feat add dispatcher

3party/libelfin/CMakeLists.txt

@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 3.10)
+project(
+  elf
+  VERSION 0.3.0
+  LANGUAGES C CXX)
+
+add_library(
+  dwarf STATIC
+  dwarf/abbrev.cc
+  dwarf/attrs.cc
+  dwarf/cursor.cc
+  dwarf/die.cc
+  dwarf/dwarf.cc
+  dwarf/elf.cc
+  dwarf/expr.cc
+  dwarf/line.cc
+  dwarf/rangelist.cc
+  dwarf/value.cc
+  dwarf/to_string.cc)
+target_include_directories(dwarf PUBLIC dwarf/)
+
+add_library(elf STATIC elf/elf.cc elf/to_string.cc elf/mmap_loader.cc)
+target_include_directories(elf PUBLIC elf/)
+target_link_libraries(elf PUBLIC dwarf)

3party/libelfin/Makefile

@@ -0,0 +1,14 @@
+all:
+	$(MAKE) -C elf
+	$(MAKE) -C dwarf
+
+install:
+	$(MAKE) -C elf install
+	$(MAKE) -C dwarf install
+
+clean:
+	$(MAKE) -C elf clean
+	$(MAKE) -C dwarf clean
+
+check:
+	cd test && ./test.sh

3party/libelfin/dwarf/.gitignore

@@ -0,0 +1,7 @@
+*.o
+to_string.cc
+libdwarf++.a
+libdwarf++.so
+libdwarf++.so.*
+libdwarf++.pc
+/doc/

3party/libelfin/dwarf/abbrev.cc

@@ -0,0 +1,176 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+static value::type
+resolve_type(DW_AT name, DW_FORM form)
+{
+        switch (form) {
+        case DW_FORM::addr:
+                return value::type::address;
+
+        case DW_FORM::block:
+        case DW_FORM::block1:
+        case DW_FORM::block2:
+        case DW_FORM::block4:
+                // Prior to DWARF 4, exprlocs didn't have their own
+                // form and were represented as blocks.
+                // XXX Should this be predicated on version?
+                switch (name) {
+                case DW_AT::location:
+                case DW_AT::byte_size:
+                case DW_AT::bit_offset:
+                case DW_AT::bit_size:
+                case DW_AT::string_length:
+                case DW_AT::lower_bound:
+                case DW_AT::return_addr:
+                case DW_AT::bit_stride:
+                case DW_AT::upper_bound:
+                case DW_AT::count:
+                case DW_AT::data_member_location:
+                case DW_AT::frame_base:
+                case DW_AT::segment:
+                case DW_AT::static_link:
+                case DW_AT::use_location:
+                case DW_AT::vtable_elem_location:
+                case DW_AT::allocated:
+                case DW_AT::associated:
+                case DW_AT::data_location:
+                case DW_AT::byte_stride:
+                        return value::type::exprloc;
+                default:
+                        return value::type::block;
+                }
+
+        case DW_FORM::data4:
+        case DW_FORM::data8:
+                // Prior to DWARF 4, section offsets didn't have their
+                // own form and were represented as data4 or data8.
+                // DWARF 3 clarified that types that accepted both
+                // constants and section offsets were to treat data4
+                // and data8 as section offsets and other constant
+                // forms as constants.
+                // XXX Should this be predicated on version?
+                switch (name) {
+                case DW_AT::location:
+                case DW_AT::stmt_list:
+                case DW_AT::string_length:
+                case DW_AT::return_addr:
+                case DW_AT::start_scope:
+                case DW_AT::data_member_location:
+                case DW_AT::frame_base:
+                case DW_AT::macro_info:
+                case DW_AT::segment:
+                case DW_AT::static_link:
+                case DW_AT::use_location:
+                case DW_AT::vtable_elem_location:
+                case DW_AT::ranges:
+                        goto sec_offset;
+                default:
+                        // Fall through
+                        break;
+                }
+        case DW_FORM::data1:
+        case DW_FORM::data2:
+                return value::type::constant;
+        case DW_FORM::udata:
+                return value::type::uconstant;
+        case DW_FORM::sdata:
+                return value::type::sconstant;
+
+        case DW_FORM::exprloc:
+                return value::type::exprloc;
+
+        case DW_FORM::flag:
+        case DW_FORM::flag_present:
+                return value::type::flag;
+
+        case DW_FORM::ref1:
+        case DW_FORM::ref2:
+        case DW_FORM::ref4:
+        case DW_FORM::ref8:
+        case DW_FORM::ref_addr:
+        case DW_FORM::ref_sig8:
+        case DW_FORM::ref_udata:
+                return value::type::reference;
+
+        case DW_FORM::string:
+        case DW_FORM::strp:
+                return value::type::string;
+
+        case DW_FORM::indirect:
+                // There's nothing meaningful we can do
+                return value::type::invalid;
+
+        case DW_FORM::sec_offset:
+        sec_offset:
+                // The type of this form depends on the attribute
+                switch (name) {
+                case DW_AT::stmt_list:
+                        return value::type::line;
+
+                case DW_AT::location:
+                case DW_AT::string_length:
+                case DW_AT::return_addr:
+                case DW_AT::data_member_location:
+                case DW_AT::frame_base:
+                case DW_AT::segment:
+                case DW_AT::static_link:
+                case DW_AT::use_location:
+                case DW_AT::vtable_elem_location:
+                        return value::type::loclist;
+
+                case DW_AT::macro_info:
+                        return value::type::mac;
+
+                case DW_AT::start_scope:
+                case DW_AT::ranges:
+                        return value::type::rangelist;
+
+                case DW_AT::lo_user...DW_AT::hi_user:
+                        //HACK: ignore vendor extensions
+                        return value::type::invalid;
+
+                default:
+                        throw format_error("DW_FORM_sec_offset not expected for attribute " +
+                                           to_string(name));
+                }
+        }
+        throw format_error("unknown attribute form " + to_string(form));
+}
+
+attribute_spec::attribute_spec(DW_AT name, DW_FORM form)
+        : name(name), form(form), type(resolve_type(name, form))
+{
+}
+
+bool
+abbrev_entry::read(cursor *cur)
+{
+        attributes.clear();
+
+        // Section 7.5.3
+        code = cur->uleb128();
+        if (!code)
+                return false;
+
+        tag = (DW_TAG)cur->uleb128();
+        children = cur->fixed<DW_CHILDREN>() == DW_CHILDREN::yes;
+        while (1) {
+                DW_AT name = (DW_AT)cur->uleb128();
+                DW_FORM form = (DW_FORM)cur->uleb128();
+                if (name == (DW_AT)0 && form == (DW_FORM)0)
+                        break;
+                attributes.push_back(attribute_spec(name, form));
+        }
+        attributes.shrink_to_fit();
+        return true;
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/attrs.cc

@@ -0,0 +1,267 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "dwarf++.hh"
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+#define AT_ANY(name)                            \
+        value at_##name(const die &d)           \
+        {                                       \
+                return d[DW_AT::name];          \
+        }                                       \
+        static_assert(true, "")
+
+#define AT_ADDRESS(name)                                \
+        taddr at_##name(const die &d)                   \
+        {                                               \
+                return d[DW_AT::name].as_address();     \
+        }                                               \
+        static_assert(true, "")
+
+#define AT_ENUM(name, type)                                \
+        type at_##name(const die &d)                            \
+        {                                                       \
+                return (type)d[DW_AT::name].as_uconstant();     \
+        }                                                       \
+        static_assert(true, "")
+
+#define AT_FLAG(name)                                   \
+        bool at_##name(const die &d)                    \
+        {                                               \
+                return d[DW_AT::name].as_flag();        \
+        }                                               \
+        static_assert(true, "")
+
+#define AT_FLAG_(name)                                  \
+        bool at_##name(const die &d)                    \
+        {                                               \
+                return d[DW_AT::name##_].as_flag();     \
+        }                                               \
+        static_assert(true, "")
+
+#define AT_REFERENCE(name)                              \
+        die at_##name(const die &d)                     \
+        {                                               \
+                return d[DW_AT::name].as_reference();   \
+        }                                               \
+        static_assert(true, "")
+
+#define AT_STRING(name)                                 \
+        string at_##name(const die &d)                  \
+        {                                               \
+                return d[DW_AT::name].as_string();      \
+        }                                               \
+        static_assert(true, "")
+
+#define AT_UDYNAMIC(name)                                       \
+        uint64_t at_##name(const die &d, expr_context *ctx)     \
+        {                                                       \
+                return _at_udynamic(DW_AT::name, d, ctx);       \
+        }                                                       \
+        static_assert(true, "")
+
+static uint64_t _at_udynamic(DW_AT attr, const die &d, expr_context *ctx, int depth = 0)
+{
+        // DWARF4 section 2.19
+        if (depth > 16)
+                throw format_error("reference depth exceeded for " + to_string(attr));
+
+        value v(d[attr]);
+        switch (v.get_type()) {
+        case value::type::constant:
+        case value::type::uconstant:
+                return v.as_uconstant();
+        case value::type::reference:
+                return _at_udynamic(attr, v.as_reference(), ctx, depth + 1);
+        case value::type::exprloc:
+                return v.as_exprloc().evaluate(ctx).value;
+        default:
+                throw format_error(to_string(attr) + " has unexpected type " +
+                                   to_string(v.get_type()));
+        }
+}
+
+//////////////////////////////////////////////////////////////////
+// 0x0X
+//
+
+AT_REFERENCE(sibling);
+// XXX location
+AT_STRING(name);
+AT_ENUM(ordering, DW_ORD);
+AT_UDYNAMIC(byte_size);
+AT_UDYNAMIC(bit_offset);
+AT_UDYNAMIC(bit_size);
+
+//////////////////////////////////////////////////////////////////
+// 0x1X
+//
+
+// XXX stmt_list
+AT_ADDRESS(low_pc);
+taddr
+at_high_pc(const die &d)
+{
+        value v(d[DW_AT::high_pc]);
+        switch (v.get_type()) {
+        case value::type::address:
+                return v.as_address();
+        case value::type::constant:
+        case value::type::uconstant:
+                return at_low_pc(d) + v.as_uconstant();
+        default:
+                throw format_error(to_string(DW_AT::high_pc) + " has unexpected type " +
+                                   to_string(v.get_type()));
+        }
+}
+AT_ENUM(language, DW_LANG);
+AT_REFERENCE(discr);
+AT_ANY(discr_value);            // XXX Signed or unsigned
+AT_ENUM(visibility, DW_VIS);
+AT_REFERENCE(import);
+// XXX string_length
+AT_REFERENCE(common_reference);
+AT_STRING(comp_dir);
+AT_ANY(const_value);
+AT_REFERENCE(containing_type);
+// XXX default_value
+
+//////////////////////////////////////////////////////////////////
+// 0x2X
+//
+
+DW_INL at_inline(const die &d)
+{
+        // XXX Missing attribute is equivalent to DW_INL_not_inlined
+        // (DWARF4 section 3.3.8)
+        return (DW_INL)d[DW_AT::inline_].as_uconstant();
+}
+AT_FLAG(is_optional);
+AT_UDYNAMIC(lower_bound);       // XXX Language-based default?
+AT_STRING(producer);
+AT_FLAG(prototyped);
+// XXX return_addr
+// XXX start_scope
+AT_UDYNAMIC(bit_stride);
+AT_UDYNAMIC(upper_bound);
+
+//////////////////////////////////////////////////////////////////
+// 0x3X
+//
+
+AT_REFERENCE(abstract_origin);
+AT_ENUM(accessibility, DW_ACCESS);
+// XXX const address_class
+AT_FLAG(artificial);
+// XXX base_types
+AT_ENUM(calling_convention, DW_CC);
+AT_UDYNAMIC(count);
+expr_result
+at_data_member_location(const die &d, expr_context *ctx, taddr base, taddr pc)
+{
+        value v(d[DW_AT::data_member_location]);
+        switch (v.get_type()) {
+        case value::type::constant:
+        case value::type::uconstant:
+                return {expr_result::type::address, base + v.as_uconstant()};
+        case value::type::exprloc:
+                return v.as_exprloc().evaluate(ctx, base);
+        case value::type::loclist:
+                // XXX
+                throw std::runtime_error("not implemented");
+        default:
+                throw format_error("DW_AT_data_member_location has unexpected type " +
+                                   to_string(v.get_type()));
+        }
+}
+// XXX decl_column decl_file decl_line
+AT_FLAG(declaration);
+// XXX discr_list
+AT_ENUM(encoding, DW_ATE);
+AT_FLAG(external);
+
+//////////////////////////////////////////////////////////////////
+// 0x4X
+//
+
+// XXX frame_base
+die at_friend(const die &d)
+{
+        return d[DW_AT::friend_].as_reference();
+}
+AT_ENUM(identifier_case, DW_ID);
+// XXX macro_info
+AT_REFERENCE(namelist_item);
+AT_REFERENCE(priority);         // XXX Computed might be useful
+// XXX segment
+AT_REFERENCE(specification);
+// XXX static_link
+AT_REFERENCE(type);
+// XXX use_location
+AT_FLAG(variable_parameter);
+// XXX 7.11 The value DW_VIRTUALITY_none is equivalent to the absence
+// of the DW_AT_virtuality attribute.
+AT_ENUM(virtuality, DW_VIRTUALITY);
+// XXX vtable_elem_location
+AT_UDYNAMIC(allocated);
+AT_UDYNAMIC(associated);
+
+//////////////////////////////////////////////////////////////////
+// 0x5X
+//
+
+// XXX data_location
+AT_UDYNAMIC(byte_stride);
+AT_ADDRESS(entry_pc);
+AT_FLAG(use_UTF8);
+AT_REFERENCE(extension);
+rangelist
+at_ranges(const die &d)
+{
+        return d[DW_AT::ranges].as_rangelist();
+}
+// XXX trampoline
+// XXX const call_column, call_file, call_line
+AT_STRING(description);
+// XXX const binary_scale
+// XXX const decimal_scale
+AT_REFERENCE(small);
+// XXX const decimal_sign
+// XXX const digit_count
+
+//////////////////////////////////////////////////////////////////
+// 0x6X
+//
+
+AT_STRING(picture_string);
+AT_FLAG_(mutable);
+AT_FLAG(threads_scaled);
+AT_FLAG_(explicit);
+AT_REFERENCE(object_pointer);
+AT_ENUM(endianity, DW_END);
+AT_FLAG(elemental);
+AT_FLAG(pure);
+AT_FLAG(recursive);
+AT_REFERENCE(signature);        // XXX Computed might be useful
+AT_FLAG(main_subprogram);
+// XXX const data_bit_offset
+AT_FLAG(const_expr);
+AT_FLAG(enum_class);
+AT_STRING(linkage_name);
+
+rangelist
+die_pc_range(const die &d)
+{
+        // DWARF4 section 2.17
+        if (d.has(DW_AT::ranges))
+                return at_ranges(d);
+        taddr low = at_low_pc(d);
+        taddr high = d.has(DW_AT::high_pc) ? at_high_pc(d) : (low + 1);
+        return rangelist({{low, high}});
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/cursor.cc

@@ -0,0 +1,207 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+#include <stdexcept>
+#include <cstring>
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+int64_t
+cursor::sleb128()
+{
+        // Appendix C
+        uint64_t result = 0;
+        unsigned shift = 0;
+        while (pos < sec->end) {
+                uint8_t byte = *(uint8_t*)(pos++);
+                result |= (uint64_t)(byte & 0x7f) << shift;
+                shift += 7;
+                if ((byte & 0x80) == 0) {
+                        if (shift < sizeof(result)*8 && (byte & 0x40))
+                                result |= -((uint64_t)1 << shift);
+                        return result;
+                }
+        }
+        underflow();
+        return 0;
+}
+
+shared_ptr<section>
+cursor::subsection()
+{
+        // Section 7.4
+        const char *begin = pos;
+        section_length length = fixed<uword>();
+        format fmt;
+        if (length < 0xfffffff0) {
+                fmt = format::dwarf32;
+                length += sizeof(uword);
+        } else if (length == 0xffffffff) {
+                length = fixed<uint64_t>();
+                fmt = format::dwarf64;
+                length += sizeof(uword) + sizeof(uint64_t);
+        } else {
+                throw format_error("initial length has reserved value");
+        }
+        pos = begin + length;
+        return make_shared<section>(sec->type, begin, length, sec->ord, fmt);
+}
+
+void
+cursor::skip_initial_length()
+{
+        switch (sec->fmt) {
+        case format::dwarf32:
+                pos += sizeof(uword);
+                break;
+        case format::dwarf64:
+                pos += sizeof(uword) + sizeof(uint64_t);
+                break;
+        default:
+                throw logic_error("cannot skip initial length with unknown format");
+        }
+}
+
+void
+cursor::skip_unit_type()
+{
+    pos += sizeof(sbyte);
+}
+
+section_offset
+cursor::offset()
+{
+        switch (sec->fmt) {
+        case format::dwarf32:
+                return fixed<uint32_t>();
+        case format::dwarf64:
+                return fixed<uint64_t>();
+        default:
+                throw logic_error("cannot read offset with unknown format");
+        }
+}
+
+void
+cursor::string(std::string &out)
+{
+        size_t size;
+        const char *p = this->cstr(&size);
+        out.resize(size);
+        memmove(&out.front(), p, size);
+}
+
+const char *
+cursor::cstr(size_t *size_out)
+{
+        // Scan string size
+        const char *p = pos;
+        while (pos < sec->end && *pos)
+                pos++;
+        if (pos == sec->end)
+                throw format_error("unterminated string");
+        if (size_out)
+                *size_out = pos - p;
+        pos++;
+        return p;
+}
+
+void
+cursor::skip_form(DW_FORM form)
+{
+        section_offset tmp;
+
+        // Section 7.5.4
+        switch (form) {
+        case DW_FORM::addr:
+                pos += sec->addr_size;
+                break;
+        case DW_FORM::sec_offset:
+        case DW_FORM::ref_addr:
+        case DW_FORM::strp:
+                switch (sec->fmt) {
+                case format::dwarf32:
+                        pos += 4;
+                        break;
+                case format::dwarf64:
+                        pos += 8;
+                        break;
+                case format::unknown:
+                        throw logic_error("cannot read form with unknown format");
+                }
+                break;
+
+                // size+data forms
+        case DW_FORM::block1:
+                tmp = fixed<ubyte>();
+                pos += tmp;
+                break;
+        case DW_FORM::block2:
+                tmp = fixed<uhalf>();
+                pos += tmp;
+                break;
+        case DW_FORM::block4:
+                tmp = fixed<uword>();
+                pos += tmp;
+                break;
+        case DW_FORM::block:
+        case DW_FORM::exprloc:
+                tmp = uleb128();
+                pos += tmp;
+                break;
+
+                // fixed-length forms
+        case DW_FORM::flag_present:
+                break;
+        case DW_FORM::flag:
+        case DW_FORM::data1:
+        case DW_FORM::ref1:
+                pos += 1;
+                break;
+        case DW_FORM::data2:
+        case DW_FORM::ref2:
+                pos += 2;
+                break;
+        case DW_FORM::data4:
+        case DW_FORM::ref4:
+                pos += 4;
+                break;
+        case DW_FORM::data8:
+        case DW_FORM::ref_sig8:
+                pos += 8;
+                break;
+
+                // variable-length forms
+        case DW_FORM::sdata:
+        case DW_FORM::udata:
+        case DW_FORM::ref_udata:
+                while (pos < sec->end && (*(uint8_t*)pos & 0x80))
+                        pos++;
+                pos++;
+                break;
+        case DW_FORM::string:
+                while (pos < sec->end && *pos)
+                        pos++;
+                pos++;
+                break;
+
+        case DW_FORM::indirect:
+                skip_form((DW_FORM)uleb128());
+                break;
+
+        default:
+                throw format_error("unknown form " + to_string(form));
+        }
+}
+
+void
+cursor::underflow()
+{
+        throw underflow_error("cannot read past end of DWARF section");
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/data.hh

@@ -0,0 +1,539 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#ifndef _DWARFPP_DW_HH_
+#define _DWARFPP_DW_HH_
+
+#include <cstdint>
+#include <string>
+
+DWARFPP_BEGIN_NAMESPACE
+
+// Integer representations (Section 7.26)
+typedef std::int8_t sbyte;
+typedef std::uint8_t ubyte;
+typedef std::uint16_t uhalf;
+typedef std::uint32_t uword;
+
+// Section offsets and lengths
+typedef std::uint64_t section_offset;
+typedef std::uint64_t section_length;
+
+// A target machine address.  Targets may use smaller addresses; this
+// represents the largest supported address type.
+typedef std::uint64_t taddr;
+
+// DIE tags (Section 7, figure 18).  typedef, friend, and namespace
+// have a trailing underscore because they are reserved words.
+enum class DW_TAG {
+    array_type           = 0x01,
+    class_type           = 0x02,
+    entry_point          = 0x03,
+    enumeration_type     = 0x04,
+    formal_parameter     = 0x05,
+    imported_declaration = 0x08,
+    label                = 0x0a,
+    lexical_block        = 0x0b,
+    member               = 0x0d,
+    pointer_type         = 0x0f,
+    reference_type       = 0x10,
+    compile_unit         = 0x11,
+    string_type          = 0x12,
+    structure_type       = 0x13,
+    subroutine_type      = 0x15,
+    typedef_             = 0x16,
+
+    union_type             = 0x17,
+    unspecified_parameters = 0x18,
+    variant                = 0x19,
+    common_block           = 0x1a,
+    common_inclusion       = 0x1b,
+    inheritance            = 0x1c,
+    inlined_subroutine     = 0x1d,
+    module                 = 0x1e,
+    ptr_to_member_type     = 0x1f,
+    set_type               = 0x20,
+    subrange_type          = 0x21,
+    with_stmt              = 0x22,
+    access_declaration     = 0x23,
+    base_type              = 0x24,
+    catch_block            = 0x25,
+    const_type             = 0x26,
+    constant               = 0x27,
+    enumerator             = 0x28,
+    file_type              = 0x29,
+    friend_                = 0x2a,
+
+    namelist                 = 0x2b,
+    namelist_item            = 0x2c,
+    packed_type              = 0x2d,
+    subprogram               = 0x2e,
+    template_type_parameter  = 0x2f,
+    template_value_parameter = 0x30,
+    thrown_type              = 0x31,
+    try_block                = 0x32,
+    variant_part             = 0x33,
+    variable                 = 0x34,
+    volatile_type            = 0x35,
+    dwarf_procedure          = 0x36,
+    restrict_type            = 0x37,
+    interface_type           = 0x38,
+    namespace_               = 0x39,
+    imported_module          = 0x3a,
+    unspecified_type         = 0x3b,
+    partial_unit             = 0x3c,
+    imported_unit            = 0x3d,
+    condition                = 0x3f,
+
+    shared_type           = 0x40,
+    type_unit             = 0x41,
+    rvalue_reference_type = 0x42,
+    template_alias        = 0x43,
+    lo_user               = 0x4080,
+    hi_user               = 0xffff,
+};
+
+std::string to_string(DW_TAG v);
+
+// Child determination (Section 7, figure 19).
+enum class DW_CHILDREN : ubyte {
+    no  = 0x00,
+    yes = 0x01,
+};
+
+std::string to_string(DW_CHILDREN v);
+
+// Attribute names (Section 7, figure 20).  inline, friend, mutable,
+// and explicit have a trailing underscore because they are reserved
+// words.
+enum class DW_AT {
+    sibling          = 0x01,// reference
+    location         = 0x02,// exprloc, loclistptr
+    name             = 0x03,// string
+    ordering         = 0x09,// constant
+    byte_size        = 0x0b,// constant, exprloc, reference
+    bit_offset       = 0x0c,// constant, exprloc, reference
+    bit_size         = 0x0d,// constant, exprloc, reference
+    stmt_list        = 0x10,// lineptr
+    low_pc           = 0x11,// address
+    high_pc          = 0x12,// address, constant
+    language         = 0x13,// constant
+    discr            = 0x15,// reference
+    discr_value      = 0x16,// constant
+    visibility       = 0x17,// constant
+    import           = 0x18,// reference
+    string_length    = 0x19,// exprloc, loclistptr
+    common_reference = 0x1a,// reference
+    comp_dir         = 0x1b,// string
+    const_value      = 0x1c,// block, constant, string
+
+    containing_type      = 0x1d,// reference
+    default_value        = 0x1e,// reference
+    inline_              = 0x20,// constant
+    is_optional          = 0x21,// flag
+    lower_bound          = 0x22,// constant, exprloc, reference
+    producer             = 0x25,// string
+    prototyped           = 0x27,// flag
+    return_addr          = 0x2a,// exprloc, loclistptr
+    start_scope          = 0x2c,// constant, rangelistptr
+    bit_stride           = 0x2e,// constant, exprloc, reference
+    upper_bound          = 0x2f,// constant, exprloc, reference
+    abstract_origin      = 0x31,// reference
+    accessibility        = 0x32,// constant
+    address_class        = 0x33,// constant
+    artificial           = 0x34,// flag
+    base_types           = 0x35,// reference
+    calling_convention   = 0x36,// constant
+    count                = 0x37,// constant, exprloc, reference
+    data_member_location = 0x38,// constant, exprloc, loclistptr
+    decl_column          = 0x39,// constant
+
+    decl_file            = 0x3a,// constant
+    decl_line            = 0x3b,// constant
+    declaration          = 0x3c,// flag
+    discr_list           = 0x3d,// block
+    encoding             = 0x3e,// constant
+    external             = 0x3f,// flag
+    frame_base           = 0x40,// exprloc, loclistptr
+    friend_              = 0x41,// reference
+    identifier_case      = 0x42,// constant
+    macro_info           = 0x43,// macptr
+    namelist_item        = 0x44,// reference
+    priority             = 0x45,// reference
+    segment              = 0x46,// exprloc, loclistptr
+    specification        = 0x47,// reference
+    static_link          = 0x48,// exprloc, loclistptr
+    type                 = 0x49,// reference
+    use_location         = 0x4a,// exprloc, loclistptr
+    variable_parameter   = 0x4b,// flag
+    virtuality           = 0x4c,// constant
+    vtable_elem_location = 0x4d,// exprloc, loclistptr
+
+    // DWARF 3
+    allocated      = 0x4e,// constant, exprloc, reference
+    associated     = 0x4f,// constant, exprloc, reference
+    data_location  = 0x50,// exprloc
+    byte_stride    = 0x51,// constant, exprloc, reference
+    entry_pc       = 0x52,// address
+    use_UTF8       = 0x53,// flag
+    extension      = 0x54,// reference
+    ranges         = 0x55,// rangelistptr
+    trampoline     = 0x56,// address, flag, reference, string
+    call_column    = 0x57,// constant
+    call_file      = 0x58,// constant
+    call_line      = 0x59,// constant
+    description    = 0x5a,// string
+    binary_scale   = 0x5b,// constant
+    decimal_scale  = 0x5c,// constant
+    small          = 0x5d,// reference
+    decimal_sign   = 0x5e,// constant
+    digit_count    = 0x5f,// constant
+    picture_string = 0x60,// string
+    mutable_       = 0x61,// flag
+
+    threads_scaled = 0x62,// flag
+    explicit_      = 0x63,// flag
+    object_pointer = 0x64,// reference
+    endianity      = 0x65,// constant
+    elemental      = 0x66,// flag
+    pure           = 0x67,// flag
+    recursive      = 0x68,// flag
+
+    // DWARF 4
+    signature       = 0x69,// reference
+    main_subprogram = 0x6a,// flag
+    data_bit_offset = 0x6b,// constant
+    const_expr      = 0x6c,// flag
+    enum_class      = 0x6d,// flag
+    linkage_name    = 0x6e,// string
+
+    lo_user = 0x2000,
+    hi_user = 0x3fff,
+};
+
+std::string to_string(DW_AT v);
+
+// Attribute form encodings (Section 7, figure 21)
+enum class DW_FORM {
+    addr     = 0x01,// address
+    block2   = 0x03,// block
+    block4   = 0x04,// block
+    data2    = 0x05,// constant
+    data4    = 0x06,// constant
+    data8    = 0x07,// constant
+    string   = 0x08,// string
+    block    = 0x09,// block
+    block1   = 0x0a,// block
+    data1    = 0x0b,// constant
+    flag     = 0x0c,// flag
+    sdata    = 0x0d,// constant
+    strp     = 0x0e,// string
+    udata    = 0x0f,// constant
+    ref_addr = 0x10,// reference
+    ref1     = 0x11,// reference
+    ref2     = 0x12,// reference
+    ref4     = 0x13,// reference
+    ref8     = 0x14,// reference
+
+    ref_udata = 0x15,// reference
+    indirect  = 0x16,// (Section 7.5.3)
+
+    // DWARF 4
+    sec_offset     = 0x17,// lineptr, loclistptr, macptr, rangelistptr
+    exprloc        = 0x18,// exprloc
+    flag_present   = 0x19,// flag
+    ref_sig8       = 0x20,// reference
+    implicit_const = 0x21,
+    loclistx       = 0x22,
+    rnglistx       = 0x23,
+    ref_sup8       = 0x24,
+    strx1          = 0x25,
+    strx2          = 0x26,
+    strx3          = 0x27,
+    strx4          = 0x28,
+    addrx1         = 0x29,
+    addrx2         = 0x2a,
+    addrx4         = 0x2c,
+    addrx3         = 0x2b,
+};
+
+std::string to_string(DW_FORM v);
+
+// DWARF operation encodings (Section 7.7.1 and figure 24)
+enum class DW_OP : ubyte {
+    addr  = 0x03,// [constant address (size target specific)]
+    deref = 0x06,
+
+    const1u = 0x08,// [1-byte constant]
+    const1s = 0x09,// [1-byte constant]
+    const2u = 0x0a,// [2-byte constant]
+    const2s = 0x0b,// [2-byte constant]
+    const4u = 0x0c,// [4-byte constant]
+    const4s = 0x0d,// [4-byte constant]
+    const8u = 0x0e,// [8-byte constant]
+    const8s = 0x0f,// [8-byte constant]
+    constu  = 0x10,// [ULEB128 constant]
+    consts  = 0x11,// [SLEB128 constant]
+    dup     = 0x12,
+    drop    = 0x13,
+    over    = 0x14,
+    pick    = 0x15,// [1-byte stack index]
+    swap    = 0x16,
+    rot     = 0x17,
+    xderef  = 0x18,
+    abs     = 0x19,
+    and_    = 0x1a,
+    div     = 0x1b,
+
+    minus       = 0x1c,
+    mod         = 0x1d,
+    mul         = 0x1e,
+    neg         = 0x1f,
+    not_        = 0x20,
+    or_         = 0x21,
+    plus        = 0x22,
+    plus_uconst = 0x23,// [ULEB128 addend]
+    shl         = 0x24,
+    shr         = 0x25,
+    shra        = 0x26,
+    xor_        = 0x27,
+    skip        = 0x2f,// [signed 2-byte constant]
+    bra         = 0x28,// [signed 2-byte constant]
+    eq          = 0x29,
+    ge          = 0x2a,
+    gt          = 0x2b,
+    le          = 0x2c,
+    lt          = 0x2d,
+    ne          = 0x2e,
+
+    // Literals 0..31 = (lit0 + literal)
+    lit0  = 0x30,
+    lit31 = 0x4f,
+
+    // Registers 0..31 = (reg0 + regnum)
+    reg0  = 0x50,
+    reg31 = 0x6f,
+
+    // Base register 0..31 = (breg0 + regnum)
+    breg0  = 0x70,// [SLEB128 offset]
+    breg31 = 0x8f,// [SLEB128 offset]
+
+    regx        = 0x90,// [ULEB128 register]
+    fbreg       = 0x91,// [SLEB128 offset]
+    bregx       = 0x92,// [ULEB128 register, SLEB128 offset]
+    piece       = 0x93,// [ULEB128 size of piece addressed]
+    deref_size  = 0x94,// [1-byte size of data retrieved]
+    xderef_size = 0x95,// [1-byte size of data retrieved]
+    nop         = 0x96,
+
+    // DWARF 3
+    push_object_address = 0x97,
+    call2               = 0x98,// [2-byte offset of DIE]
+    call4               = 0x99,// [4-byte offset of DIE]
+    call_ref            = 0x9a,// [4- or 8-byte offset of DIE]
+    form_tls_address    = 0x9b,
+    call_frame_cfa      = 0x9c,
+    bit_piece           = 0x9d,// [ULEB128 size, ULEB128 offset]
+
+    // DWARF 4
+    implicit_value = 0x9e,// [ULEB128 size, block of that size]
+    stack_value    = 0x9f,
+
+    lo_user = 0xe0,
+    hi_user = 0xff,
+};
+
+std::string to_string(DW_OP v);
+
+// DW_AT::encoding constants (DWARF4 section 7.8 figure 25)
+enum class DW_ATE {
+    address         = 0x01,
+    boolean         = 0x02,
+    complex_float   = 0x03,
+    float_          = 0x04,
+    signed_         = 0x05,
+    signed_char     = 0x06,
+    unsigned_       = 0x07,
+    unsigned_char   = 0x08,
+    imaginary_float = 0x09,
+    packed_decimal  = 0x0a,
+    numeric_string  = 0x0b,
+    edited          = 0x0c,
+    signed_fixed    = 0x0d,
+    unsigned_fixed  = 0x0e,
+    decimal_float   = 0x0f,
+
+    // DWARF 4
+    UTF = 0x10,
+
+    lo_user = 0x80,
+    hi_user = 0xff,
+};
+
+std::string to_string(DW_ATE v);
+
+// DW_AT::decimal_sign constants (DWARF4 section 7.8 figure 26)
+enum class DW_DS {
+    unsigned_          = 0x01,
+    leading_overpunch  = 0x02,
+    trailing_overpunch = 0x03,
+    leading_separate   = 0x04,
+    trailing_separate  = 0x05,
+};
+
+std::string to_string(DW_DS v);
+
+// DW_AT::endianity constants (DWARF4 section 7.8 figure 27)
+enum class DW_END {
+    default_ = 0x00,
+    big      = 0x01,
+    little   = 0x02,
+    lo_user  = 0x40,
+    hi_user  = 0xff,
+};
+
+std::string to_string(DW_END v);
+
+// DW_AT::accessibility constants (DWARF4 section 7.9 figure 28)
+enum class DW_ACCESS {
+    public_    = 0x01,
+    protected_ = 0x02,
+    private_   = 0x03,
+};
+
+std::string to_string(DW_ACCESS v);
+
+// DW_AT::visibility constants (DWARF4 section 7.10 figure 29)
+enum class DW_VIS {
+    local     = 0x01,
+    exported  = 0x02,
+    qualified = 0x03,
+};
+
+std::string to_string(DW_VIS v);
+
+// DW_AT::virtuality constants (DWARF4 section 7.11 figure 30)
+enum class DW_VIRTUALITY {
+    none         = 0x00,
+    virtual_     = 0x01,
+    pure_virtual = 0x02,
+};
+
+std::string to_string(DW_VIRTUALITY v);
+
+// DW_AT::language constants (DWARF4 section 7.12 figure 31)
+enum class DW_LANG {
+    C89         = 0x0001,// Lower bound 0
+    C           = 0x0002,// Lower bound 0
+    Ada83       = 0x0003,// Lower bound 1
+    C_plus_plus = 0x0004,// Lower bound 0
+    Cobol74     = 0x0005,// Lower bound 1
+    Cobol85     = 0x0006,// Lower bound 1
+    Fortran77   = 0x0007,// Lower bound 1
+    Fortran90   = 0x0008,// Lower bound 1
+    Pascal83    = 0x0009,// Lower bound 1
+    Modula2     = 0x000a,// Lower bound 1
+    Java        = 0x000b,// Lower bound 0
+    C99         = 0x000c,// Lower bound 0
+    Ada95       = 0x000d,// Lower bound 1
+    Fortran95   = 0x000e,// Lower bound 1
+    PLI         = 0x000f,// Lower bound 1
+
+    ObjC           = 0x0010,// Lower bound 0
+    ObjC_plus_plus = 0x0011,// Lower bound 0
+    UPC            = 0x0012,// Lower bound 0
+    D              = 0x0013,// Lower bound 0
+    Python         = 0x0014,// Lower bound 0
+    lo_user        = 0x8000,
+    hi_user        = 0xffff,
+};
+
+std::string to_string(DW_LANG v);
+
+// DW_AT::identifier_case constants (DWARF4 section 7.14 figure 32)
+enum class DW_ID {
+    case_sensitive   = 0x00,
+    up_case          = 0x01,
+    down_case        = 0x02,
+    case_insensitive = 0x03,
+};
+
+std::string to_string(DW_ID v);
+
+// DW_AT::calling_convention constants (DWARF4 section 7.15 figure 33)
+enum class DW_CC {
+    normal  = 0x01,
+    program = 0x02,
+    nocall  = 0x03,
+    lo_user = 0x40,
+    hi_user = 0xff,
+};
+
+std::string to_string(DW_CC v);
+
+// DW_AT::inline constants (DWARF4 section 7.16 figure 34)
+enum class DW_INL {
+    not_inlined          = 0x00,
+    inlined              = 0x01,
+    declared_not_inlined = 0x02,
+    declared_inlined     = 0x03,
+};
+
+std::string to_string(DW_INL v);
+
+// DW_AT::ordering constants (DWARF4 section 7.17 figure 35)
+enum class DW_ORD {
+    row_major = 0x00,
+    col_major = 0x01,
+};
+
+std::string to_string(DW_ORD v);
+
+// DW_AT::discr_list constants (DWARF4 section 7.18 figure 36)
+enum class DW_DSC {
+    label = 0x00,
+    range = 0x01,
+};
+
+std::string to_string(DW_DSC v);
+
+// Line number standard opcodes (DWARF4 section 7.21 figure 37)
+enum class DW_LNS {
+    copy             = 0x01,
+    advance_pc       = 0x02,
+    advance_line     = 0x03,
+    set_file         = 0x04,
+    set_column       = 0x05,
+    negate_stmt      = 0x06,
+    set_basic_block  = 0x07,
+    const_add_pc     = 0x08,
+    fixed_advance_pc = 0x09,
+
+    // DWARF 3
+    set_prologue_end   = 0x0a,
+    set_epilogue_begin = 0x0b,
+    set_isa            = 0x0c,
+};
+
+std::string to_string(DW_LNS v);
+
+// Line number extended opcodes (DWARF4 section 7.21 figure 38)
+enum class DW_LNE {
+    end_sequence = 0x01,
+    set_address  = 0x02,
+    define_file  = 0x03,
+
+    // DWARF 4
+    set_discriminator = 0x04,
+
+    // DWARF 3
+    lo_user = 0x80,
+    hi_user = 0xff,
+};
+
+std::string to_string(DW_LNE v);
+
+DWARFPP_END_NAMESPACE
+
+#endif

3party/libelfin/dwarf/die.cc

@@ -0,0 +1,202 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+die::die(const unit *cu)
+        : cu(cu), abbrev(nullptr)
+{
+}
+
+const unit &
+die::get_unit() const
+{
+        return *cu;
+}
+
+section_offset
+die::get_section_offset() const
+{
+        return cu->get_section_offset() + offset;
+}
+
+void
+die::read(section_offset off)
+{
+        cursor cur(cu->data(), off);
+
+        offset = off;
+
+        abbrev_code acode = cur.uleb128();
+        if (acode == 0) {
+                abbrev = nullptr;
+                next = cur.get_section_offset();
+                return;
+        }
+        abbrev = &cu->get_abbrev(acode);
+
+        tag = abbrev->tag;
+
+        // XXX We can pre-compute almost all of this work in the
+        // abbrev_entry.
+        attrs.clear();
+        attrs.reserve(abbrev->attributes.size());
+        for (auto &attr : abbrev->attributes) {
+                attrs.push_back(cur.get_section_offset());
+                cur.skip_form(attr.form);
+        }
+        next = cur.get_section_offset();
+}
+
+bool
+die::has(DW_AT attr) const
+{
+        if (!abbrev)
+                return false;
+        // XXX Totally lame
+        for (auto &a : abbrev->attributes)
+                if (a.name == attr)
+                        return true;
+        return false;
+}
+
+value
+die::operator[](DW_AT attr) const
+{
+        // XXX We can pre-compute almost all of this work in the
+        // abbrev_entry.
+        if (abbrev) {
+                int i = 0;
+                for (auto &a : abbrev->attributes) {
+                        if (a.name == attr)
+                                return value(cu, a.name, a.form, a.type, attrs[i]);
+                        i++;
+                }
+        }
+        throw out_of_range("DIE does not have attribute " + to_string(attr));
+}
+
+value
+die::resolve(DW_AT attr) const
+{
+        // DWARF4 section 2.13, DWARF4 section 3.3.8
+
+        // DWARF4 is unclear about what to do when there's both a
+        // DW_AT::specification and a DW_AT::abstract_origin.
+        // Conceptually, though, a concrete inlined instance cannot
+        // itself complete an external function that wasn't first
+        // completed by its abstract instance, so we first try to
+        // resolve abstract_origin, then we resolve specification.
+
+        // XXX This traverses the abbrevs at least twice and
+        // potentially several more times
+
+        if (has(attr))
+                return (*this)[attr];
+
+        if (has(DW_AT::abstract_origin)) {
+                die ao = (*this)[DW_AT::abstract_origin].as_reference();
+                if (ao.has(attr))
+                        return ao[attr];
+                if (ao.has(DW_AT::specification)) {
+                        die s = ao[DW_AT::specification].as_reference();
+                        if (s.has(attr))
+                                return s[attr];
+                }
+        } else if (has(DW_AT::specification)) {
+                die s = (*this)[DW_AT::specification].as_reference();
+                if (s.has(attr))
+                        return s[attr];
+        }
+
+        return value();
+}
+
+die::iterator
+die::begin() const
+{
+        if (!abbrev || !abbrev->children)
+                return end();
+        return iterator(cu, next);
+}
+
+die::iterator::iterator(const unit *cu, section_offset off)
+        : d(cu)
+{
+        d.read(off);
+}
+
+die::iterator &
+die::iterator::operator++()
+{
+        if (!d.abbrev)
+                return *this;
+
+        if (!d.abbrev->children) {
+                // The DIE has no children, so its successor follows
+                // immediately
+                d.read(d.next);
+        } else if (d.has(DW_AT::sibling)) {
+                // They made it easy on us.  Follow the sibling
+                // pointer.  XXX Probably worth optimizing
+                d = d[DW_AT::sibling].as_reference();
+        } else {
+                // It's a hard-knock life.  We have to iterate through
+                // the children to find the next DIE.
+                // XXX Particularly unfortunate if the user is doing a
+                // DFS, since this will result in N^2 behavior.  Maybe
+                // a small cache of terminator locations in the CU?
+                iterator sub(d.cu, d.next);
+                while (sub->abbrev)
+                        ++sub;
+                d.read(sub->next);
+        }
+
+        return *this;
+}
+
+const vector<pair<DW_AT, value> >
+die::attributes() const
+{
+        vector<pair<DW_AT, value> > res;
+
+        if (!abbrev)
+                return res;
+
+        // XXX Quite slow, especially when using this to traverse an
+        // entire DIE tree since each DIE will produce a new vector
+        // (whereas other vectors get reused).  Might be worth a
+        // custom iterator.
+        int i = 0;
+        for (auto &a : abbrev->attributes) {
+                res.push_back(make_pair(a.name, value(cu, a.name, a.form, a.type, attrs[i])));
+                i++;
+        }
+        return res;
+}
+
+bool
+die::operator==(const die &o) const
+{
+        return cu == o.cu && offset == o.offset;
+}
+
+bool
+die::operator!=(const die &o) const
+{
+        return !(*this == o);
+}
+
+DWARFPP_END_NAMESPACE
+
+size_t
+std::hash<dwarf::die>::operator()(const dwarf::die &a) const
+{
+        return hash<decltype(a.cu)>()(a.cu) ^
+                hash<decltype(a.get_unit_offset())>()(a.get_unit_offset());
+}

3party/libelfin/dwarf/die_str_map.cc

@@ -0,0 +1,118 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+#include <cstring>
+#include <unordered_set>
+
+using namespace std;
+
+// XXX Make this more readily available?
+namespace std {
+        template<>
+        struct hash<dwarf::DW_TAG>
+        {
+                typedef size_t result_type;
+                typedef dwarf::DW_TAG argument_type;
+                result_type operator()(argument_type a) const
+                {
+                        return (result_type)a;
+                }
+        };
+}
+
+DWARFPP_BEGIN_NAMESPACE
+
+struct string_hash
+{
+        typedef size_t result_type;
+        typedef const char *argument_type;
+        result_type operator()(const char *s) const
+        {
+                result_type h = 0;
+                for (; *s; ++s)
+                        h += 33 * h + *s;
+                return h;
+        }
+};
+
+struct string_eq 
+{
+        typedef bool result_type;
+        typedef const char *first_argument_type;
+        typedef const char *second_argument_type;
+        bool operator()(const char *x, const char *y) const
+        {
+                return strcmp(x, y) == 0;
+        }
+};
+
+struct die_str_map::impl
+{
+        impl(const die &parent, DW_AT attr,
+             const initializer_list<DW_TAG> &accept)
+                : attr(attr), accept(accept.begin(), accept.end()),
+                  pos(parent.begin()), end(parent.end()) { }
+
+        unordered_map<const char*, die, string_hash, string_eq> str_map;
+        DW_AT attr;
+        unordered_set<DW_TAG> accept;
+        die::iterator pos, end;
+        die invalid;
+};
+
+die_str_map::die_str_map(const die &parent, DW_AT attr,
+                         const initializer_list<DW_TAG> &accept)
+        : m(make_shared<impl>(parent, attr, accept))
+{
+}
+
+die_str_map
+die_str_map::from_type_names(const die &parent)
+{
+        return die_str_map
+                (parent, DW_AT::name,
+                 // All DWARF type tags (this is everything that ends
+                 // with _type except thrown_type).
+                 {DW_TAG::array_type, DW_TAG::class_type,
+                  DW_TAG::enumeration_type, DW_TAG::pointer_type,
+                  DW_TAG::reference_type, DW_TAG::string_type,
+                  DW_TAG::structure_type, DW_TAG::subroutine_type,
+                  DW_TAG::union_type, DW_TAG::ptr_to_member_type,
+                  DW_TAG::set_type, DW_TAG::subrange_type,
+                  DW_TAG::base_type, DW_TAG::const_type,
+                  DW_TAG::file_type, DW_TAG::packed_type,
+                  DW_TAG::volatile_type, DW_TAG::restrict_type,
+                  DW_TAG::interface_type, DW_TAG::unspecified_type,
+                  DW_TAG::shared_type, DW_TAG::rvalue_reference_type});
+}
+
+const die &
+die_str_map::operator[](const char *val) const
+{
+        // Do we have this value?
+        auto it = m->str_map.find(val);
+        if (it != m->str_map.end())
+                return it->second;
+        // Read more until we find the value or the end
+        while (m->pos != m->end) {
+                const die &d = *m->pos;
+                ++m->pos;
+
+                if (!m->accept.count(d.tag) || !d.has(m->attr))
+                        continue;
+                value dval(d[m->attr]);
+                if (dval.get_type() != value::type::string)
+                        continue;
+                const char *dstr = dval.as_cstr();
+                m->str_map[dstr] = d;
+                if (strcmp(val, dstr) == 0)
+                        return m->str_map[dstr];
+        }
+        // Not found
+        return m->invalid;
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/dwarf.cc

@@ -0,0 +1,366 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+//////////////////////////////////////////////////////////////////
+// class dwarf
+//
+
+struct dwarf::impl
+{
+        impl(const std::shared_ptr<loader> &l)
+                : l(l), have_type_units(false) { }
+
+        std::shared_ptr<loader> l;
+
+        std::shared_ptr<section> sec_info;
+        std::shared_ptr<section> sec_abbrev;
+
+        std::vector<compilation_unit> compilation_units;
+
+        std::unordered_map<uint64_t, type_unit> type_units;
+        bool have_type_units;
+
+        std::map<section_type, std::shared_ptr<section> > sections;
+};
+
+dwarf::dwarf(const std::shared_ptr<loader> &l)
+        : m(make_shared<impl>(l))
+{
+        const void *data;
+        size_t size;
+
+        // Get required sections
+        data = l->load(section_type::info, &size);
+        if (!data)
+                throw format_error("required .debug_info section missing");
+        m->sec_info = make_shared<section>(section_type::info, data, size, byte_order::lsb);
+
+        // Sniff the endianness from the version field of the first
+        // CU. This is always a small but non-zero integer.
+        cursor endcur(m->sec_info);
+        // Skip length.
+        section_length length = endcur.fixed<uword>();
+        if (length == 0xffffffff)
+                endcur.fixed<uint64_t>();
+        // Get version in both little and big endian.
+        uhalf version = endcur.fixed<uhalf>();
+        uhalf versionbe = (version >> 8) | ((version & 0xFF) << 8);
+        if (versionbe < version) {
+                m->sec_info = make_shared<section>(section_type::info, data, size, byte_order::msb);
+        }
+
+        data = l->load(section_type::abbrev, &size);
+        if (!data)
+                throw format_error("required .debug_abbrev section missing");
+        m->sec_abbrev = make_shared<section>(section_type::abbrev, data, size, m->sec_info->ord);
+
+        // Get compilation units.  Everything derives from these, so
+        // there's no point in doing it lazily.
+        cursor infocur(m->sec_info);
+        while (!infocur.end()) {
+                // XXX Circular reference.  Given that we now require
+                // the dwarf object to stick around for DIEs, maybe we
+                // might as well require that for units, too.
+                m->compilation_units.emplace_back(
+                        *this, infocur.get_section_offset());
+                infocur.subsection();
+        }
+}
+
+dwarf::~dwarf()
+{
+}
+
+const std::vector<compilation_unit> &
+dwarf::compilation_units() const
+{
+        static std::vector<compilation_unit> empty;
+        if (!m)
+                return empty;
+        return m->compilation_units;
+}
+
+const type_unit &
+dwarf::get_type_unit(uint64_t type_signature) const
+{
+        if (!m->have_type_units) {
+                cursor tucur(get_section(section_type::types));
+                while (!tucur.end()) {
+                        // XXX Circular reference
+                        type_unit tu(*this, tucur.get_section_offset());
+                        m->type_units[tu.get_type_signature()] = tu;
+                        tucur.subsection();
+                }
+                m->have_type_units = true;
+        }
+        if (!m->type_units.count(type_signature))
+                throw out_of_range("type signature 0x" + to_hex(type_signature));
+        return m->type_units[type_signature];
+}
+
+std::shared_ptr<section>
+dwarf::get_section(section_type type) const
+{
+        if (type == section_type::info)
+                return m->sec_info;
+        if (type == section_type::abbrev)
+                return m->sec_abbrev;
+
+        auto it = m->sections.find(type);
+        if (it != m->sections.end())
+                return it->second;
+
+        size_t size;
+        const void *data = m->l->load(type, &size);
+        if (!data)
+                throw format_error(std::string(elf::section_type_to_name(type))
+                                   + " section missing");
+        m->sections[type] = std::make_shared<section>(section_type::str, data, size, m->sec_info->ord);
+        return m->sections[type];
+}
+
+//////////////////////////////////////////////////////////////////
+// class unit
+//
+
+/**
+ * Implementation of a unit.
+ */
+struct unit::impl
+{
+        const dwarf file;
+        const section_offset offset;
+        const std::shared_ptr<section> subsec;
+        const section_offset debug_abbrev_offset;
+        const section_offset root_offset;
+
+        // Type unit-only values
+        const uint64_t type_signature;
+        const section_offset type_offset;
+
+        // Lazily constructed root and type DIEs
+        die root, type;
+
+        // Lazily constructed line table
+        line_table lt;
+
+        // Map from abbrev code to abbrev.  If the map is dense, it
+        // will be stored in the vector; otherwise it will be stored
+        // in the map.
+        bool have_abbrevs;
+        std::vector<abbrev_entry> abbrevs_vec;
+        std::unordered_map<abbrev_code, abbrev_entry> abbrevs_map;
+
+        impl(const dwarf &file, section_offset offset,
+             const std::shared_ptr<section> &subsec,
+             section_offset debug_abbrev_offset, section_offset root_offset,
+             uint64_t type_signature = 0, section_offset type_offset = 0)
+                : file(file), offset(offset), subsec(subsec),
+                  debug_abbrev_offset(debug_abbrev_offset),
+                  root_offset(root_offset), type_signature(type_signature),
+                  type_offset(type_offset), have_abbrevs(false) { }
+
+        void force_abbrevs();
+};
+
+unit::~unit()
+{
+}
+
+const dwarf &
+unit::get_dwarf() const
+{
+        return m->file;
+}
+
+section_offset
+unit::get_section_offset() const
+{
+        return m->offset;
+}
+
+const die&
+unit::root() const
+{
+        if (!m->root.valid()) {
+                m->force_abbrevs();
+                m->root = die(this);
+                m->root.read(m->root_offset);
+        }
+        return m->root;
+}
+
+const std::shared_ptr<section> &
+unit::data() const
+{
+        return m->subsec;
+}
+
+const abbrev_entry &
+unit::get_abbrev(abbrev_code acode) const
+{
+        if (!m->have_abbrevs)
+                m->force_abbrevs();
+
+        if (!m->abbrevs_vec.empty()) {
+                if (acode >= m->abbrevs_vec.size())
+                        goto unknown;
+                const abbrev_entry &entry = m->abbrevs_vec[acode];
+                if (entry.code == 0)
+                        goto unknown;
+                return entry;
+        } else {
+                auto it = m->abbrevs_map.find(acode);
+                if (it == m->abbrevs_map.end())
+                        goto unknown;
+                return it->second;
+        }
+
+unknown:
+        throw format_error("unknown abbrev code 0x" + to_hex(acode));
+}
+
+void
+unit::impl::force_abbrevs()
+{
+        // XXX Compilation units can share abbrevs.  Parse each table
+        // at most once.
+        if (have_abbrevs)
+                return;
+
+        // Section 7.5.3
+        cursor c(file.get_section(section_type::abbrev),
+                 debug_abbrev_offset);
+        abbrev_entry entry;
+        abbrev_code highest = 0;
+        while (entry.read(&c)) {
+                abbrevs_map[entry.code] = entry;
+                if (entry.code > highest)
+                        highest = entry.code;
+        }
+
+        // Typically, abbrev codes are assigned linearly, so it's more
+        // space efficient and time efficient to store the table in a
+        // vector.  Convert to a vector if it's dense enough, by some
+        // rough estimate of "enough".
+        if (highest * 10 < abbrevs_map.size() * 15) {
+                // Move the map into the vector
+                abbrevs_vec.resize(highest + 1);
+                for (auto &entry : abbrevs_map)
+                        abbrevs_vec[entry.first] = move(entry.second);
+                abbrevs_map.clear();
+        }
+
+        have_abbrevs = true;
+}
+
+//////////////////////////////////////////////////////////////////
+// class compilation_unit
+//
+
+compilation_unit::compilation_unit(const dwarf &file, section_offset offset)
+{
+        // Read the CU header (DWARF4 section 7.5.1.1)
+        cursor cur(file.get_section(section_type::info), offset);
+        std::shared_ptr<section> subsec = cur.subsection();
+        cursor sub(subsec);
+        sub.skip_initial_length();
+        uhalf version = sub.fixed<uhalf>();
+        (void)version;
+        if (version > 5)
+                throw format_error("unknown compilation unit version " + std::to_string(version));
+        // .debug_abbrev-relative offset of this unit's abbrevs
+        section_offset debug_abbrev_offset;
+        if(version >= 5)
+        {
+            sub.skip_unit_type();
+            ubyte address_size = sub.fixed<ubyte>();
+            subsec->addr_size = address_size;
+            debug_abbrev_offset = sub.offset();
+        }
+        else {
+            debug_abbrev_offset = sub.offset();
+            ubyte address_size = sub.fixed<ubyte>();
+            subsec->addr_size = address_size;
+        }
+
+        m = make_shared<impl>(file, offset, subsec, debug_abbrev_offset,
+                              sub.get_section_offset());
+}
+
+const line_table &
+compilation_unit::get_line_table() const
+{
+        if (!m->lt.valid()) {
+                const die &d = root();
+                if (!d.has(DW_AT::stmt_list) || !d.has(DW_AT::name))
+                        goto done;
+
+                shared_ptr<section> sec;
+                try {
+                        sec = m->file.get_section(section_type::line);
+                } catch (format_error &e) {
+                        goto done;
+                }
+
+                auto comp_dir = d.has(DW_AT::comp_dir) ? at_comp_dir(d) : "";
+                
+                m->lt = line_table(sec, d[DW_AT::stmt_list].as_sec_offset(),
+                                   m->subsec->addr_size, comp_dir,
+                                   at_name(d));
+        }
+done:
+        return m->lt;
+}
+
+//////////////////////////////////////////////////////////////////
+// class type_unit
+//
+
+type_unit::type_unit(const dwarf &file, section_offset offset)
+{
+        // Read the type unit header (DWARF4 section 7.5.1.2)
+        cursor cur(file.get_section(section_type::types), offset);
+        std::shared_ptr<section> subsec = cur.subsection();
+        cursor sub(subsec);
+        sub.skip_initial_length();
+        uhalf version = sub.fixed<uhalf>();
+        if (version != 4)
+                throw format_error("unknown type unit version " + std::to_string(version));
+        // .debug_abbrev-relative offset of this unit's abbrevs
+        section_offset debug_abbrev_offset = sub.offset();
+        ubyte address_size = sub.fixed<ubyte>();
+        subsec->addr_size = address_size;
+        uint64_t type_signature = sub.fixed<uint64_t>();
+        section_offset type_offset = sub.offset();
+
+        m = make_shared<impl>(file, offset, subsec, debug_abbrev_offset,
+                              sub.get_section_offset(), type_signature,
+                              type_offset);
+}
+
+uint64_t
+type_unit::get_type_signature() const
+{
+        return m->type_signature;
+}
+
+const die &
+type_unit::type() const
+{
+        if (!m->type.valid()) {
+                m->force_abbrevs();
+                m->type = die(this);
+                m->type.read(m->type_offset);
+        }
+        return m->type;
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/elf.cc

@@ -0,0 +1,54 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "dwarf++.hh"
+
+#include <cstring>
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+static const struct
+{
+        const char *name;
+        section_type type;
+} sections[] = {
+        {".debug_abbrev",   section_type::abbrev},
+        {".debug_aranges",  section_type::aranges},
+        {".debug_frame",    section_type::frame},
+        {".debug_info",     section_type::info},
+        {".debug_line",     section_type::line},
+        {".debug_loc",      section_type::loc},
+        {".debug_macinfo",  section_type::macinfo},
+        {".debug_pubnames", section_type::pubnames},
+        {".debug_pubtypes", section_type::pubtypes},
+        {".debug_ranges",   section_type::ranges},
+        {".debug_str",      section_type::str},
+        {".debug_types",    section_type::types},
+};
+
+bool
+elf::section_name_to_type(const char *name, section_type *out)
+{
+        for (auto &sec : sections) {
+                if (strcmp(sec.name, name) == 0) {
+                        *out = sec.type;
+                        return true;
+                }
+        }
+        return false;
+}
+
+const char *
+elf::section_type_to_name(section_type type)
+{
+        for (auto &sec : sections) {
+                if (sec.type == type)
+                        return sec.name;
+        }
+        return nullptr;
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/expr.cc

@@ -0,0 +1,423 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+expr_context no_expr_context;
+
+expr::expr(const unit *cu,
+           section_offset offset, section_length len)
+        : cu(cu), offset(offset), len(len)
+{
+}
+
+expr_result
+expr::evaluate(expr_context *ctx) const
+{
+        return evaluate(ctx, {});
+}
+
+expr_result
+expr::evaluate(expr_context *ctx, taddr argument) const
+{
+        return evaluate(ctx, {argument});
+}
+
+expr_result
+expr::evaluate(expr_context *ctx, const std::initializer_list<taddr> &arguments) const
+{
+        // The stack machine's stack.  The top of the stack is
+        // stack.back().
+        // XXX This stack must be in target machine representation,
+        // since I see both (DW_OP_breg0 (eax): -28; DW_OP_stack_value)
+        // and (DW_OP_lit1; DW_OP_stack_value).
+        small_vector<taddr, 8> stack;
+
+        // Create the initial stack.  arguments are in reverse order
+        // (that is, element 0 is TOS), so reverse it.
+        stack.reserve(arguments.size());
+        for (const taddr *elt = arguments.end() - 1;
+             elt >= arguments.begin(); elt--)
+                stack.push_back(*elt);
+
+        // Create a subsection for just this expression so we can
+        // easily detect the end (including premature end).
+        auto cusec = cu->data();
+        shared_ptr<section> subsec
+                (make_shared<section>(cusec->type,
+                                      cusec->begin + offset, len,
+                                      cusec->ord, cusec->fmt,
+                                      cusec->addr_size));
+        cursor cur(subsec);
+
+        // Prepare the expression result.  Some location descriptions
+        // create the result directly, rather than using the top of
+        // stack.
+        expr_result result;
+
+        // 2.6.1.1.4 Empty location descriptions
+        if (cur.end()) {
+                result.location_type = expr_result::type::empty;
+                result.value = 0;
+                return result;
+        }
+
+        // Assume the result is an address for now and should be
+        // grabbed from the top of stack at the end.
+        result.location_type = expr_result::type::address;
+
+        // Execute!
+        while (!cur.end()) {
+#define CHECK() do { if (stack.empty()) goto underflow; } while (0)
+#define CHECKN(n) do { if (stack.size() < n) goto underflow; } while (0)
+                union
+                {
+                        uint64_t u;
+                        int64_t s;
+                } tmp1, tmp2, tmp3;
+                static_assert(sizeof(tmp1) == sizeof(taddr), "taddr is not 64 bits");
+
+                // Tell GCC to warn us about missing switch cases,
+                // even though we have a default case.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic warning "-Wswitch-enum"
+                DW_OP op = (DW_OP)cur.fixed<ubyte>();
+                switch (op) {
+                        // 2.5.1.1 Literal encodings
+                case DW_OP::lit0...DW_OP::lit31:
+                        stack.push_back((unsigned)op - (unsigned)DW_OP::lit0);
+                        break;
+                case DW_OP::addr:
+                        stack.push_back(cur.address());
+                        break;
+                case DW_OP::const1u:
+                        stack.push_back(cur.fixed<uint8_t>());
+                        break;
+                case DW_OP::const2u:
+                        stack.push_back(cur.fixed<uint16_t>());
+                        break;
+                case DW_OP::const4u:
+                        stack.push_back(cur.fixed<uint32_t>());
+                        break;
+                case DW_OP::const8u:
+                        stack.push_back(cur.fixed<uint64_t>());
+                        break;
+                case DW_OP::const1s:
+                        stack.push_back(cur.fixed<int8_t>());
+                        break;
+                case DW_OP::const2s:
+                        stack.push_back(cur.fixed<int16_t>());
+                        break;
+                case DW_OP::const4s:
+                        stack.push_back(cur.fixed<int32_t>());
+                        break;
+                case DW_OP::const8s:
+                        stack.push_back(cur.fixed<int64_t>());
+                        break;
+                case DW_OP::constu:
+                        stack.push_back(cur.uleb128());
+                        break;
+                case DW_OP::consts:
+                        stack.push_back(cur.sleb128());
+                        break;
+
+                        // 2.5.1.2 Register based addressing
+                case DW_OP::fbreg:
+                        // XXX
+                        throw runtime_error("DW_OP_fbreg not implemented");
+                case DW_OP::breg0...DW_OP::breg31:
+                        tmp1.u = (unsigned)op - (unsigned)DW_OP::breg0;
+                        tmp2.s = cur.sleb128();
+                        stack.push_back((int64_t)ctx->reg(tmp1.u) + tmp2.s);
+                        break;
+                case DW_OP::bregx:
+                        tmp1.u = cur.uleb128();
+                        tmp2.s = cur.sleb128();
+                        stack.push_back((int64_t)ctx->reg(tmp1.u) + tmp2.s);
+                        break;
+
+                        // 2.5.1.3 Stack operations
+                case DW_OP::dup:
+                        CHECK();
+                        stack.push_back(stack.back());
+                        break;
+                case DW_OP::drop:
+                        CHECK();
+                        stack.pop_back();
+                        break;
+                case DW_OP::pick:
+                        tmp1.u = cur.fixed<uint8_t>();
+                        CHECKN(tmp1.u);
+                        stack.push_back(stack.revat(tmp1.u));
+                        break;
+                case DW_OP::over:
+                        CHECKN(2);
+                        stack.push_back(stack.revat(1));
+                        break;
+                case DW_OP::swap:
+                        CHECKN(2);
+                        tmp1.u = stack.back();
+                        stack.back() = stack.revat(1);
+                        stack.revat(1) = tmp1.u;
+                        break;
+                case DW_OP::rot:
+                        CHECKN(3);
+                        tmp1.u = stack.back();
+                        stack.back() = stack.revat(1);
+                        stack.revat(1) = stack.revat(2);
+                        stack.revat(2) = tmp1.u;
+                        break;
+                case DW_OP::deref:
+                        tmp1.u = subsec->addr_size;
+                        goto deref_common;
+                case DW_OP::deref_size:
+                        tmp1.u = cur.fixed<uint8_t>();
+                        if (tmp1.u > subsec->addr_size)
+                                throw expr_error("DW_OP_deref_size operand exceeds address size");
+                deref_common:
+                        CHECK();
+                        stack.back() = ctx->deref_size(stack.back(), tmp1.u);
+                        break;
+                case DW_OP::xderef:
+                        tmp1.u = subsec->addr_size;
+                        goto xderef_common;
+                case DW_OP::xderef_size:
+                        tmp1.u = cur.fixed<uint8_t>();
+                        if (tmp1.u > subsec->addr_size)
+                                throw expr_error("DW_OP_xderef_size operand exceeds address size");
+                xderef_common:
+                        CHECKN(2);
+                        tmp2.u = stack.back();
+                        stack.pop_back();
+                        stack.back() = ctx->xderef_size(tmp2.u, stack.back(), tmp1.u);
+                        break;
+                case DW_OP::push_object_address:
+                        // XXX
+                        throw runtime_error("DW_OP_push_object_address not implemented");
+                case DW_OP::form_tls_address:
+                        CHECK();
+                        stack.back() = ctx->form_tls_address(stack.back());
+                        break;
+                case DW_OP::call_frame_cfa:
+                        // XXX
+                        throw runtime_error("DW_OP_call_frame_cfa not implemented");
+
+                        // 2.5.1.4 Arithmetic and logical operations
+#define UBINOP(binop)                                                   \
+                        do {                                            \
+                                CHECKN(2);                              \
+                                tmp1.u = stack.back();                  \
+                                stack.pop_back();                       \
+                                tmp2.u = stack.back();                  \
+                                stack.back() = tmp2.u binop tmp1.u;     \
+                        } while (0)
+                case DW_OP::abs:
+                        CHECK();
+                        tmp1.u = stack.back();
+                        if (tmp1.s < 0)
+                                tmp1.s = -tmp1.s;
+                        stack.back() = tmp1.u;
+                        break;
+                case DW_OP::and_:
+                        UBINOP(&);
+                        break;
+                case DW_OP::div:
+                        CHECKN(2);
+                        tmp1.u = stack.back();
+                        stack.pop_back();
+                        tmp2.u = stack.back();
+                        tmp3.s = tmp1.s / tmp2.s;
+                        stack.back() = tmp3.u;
+                        break;
+                case DW_OP::minus:
+                        UBINOP(-);
+                        break;
+                case DW_OP::mod:
+                        UBINOP(%);
+                        break;
+                case DW_OP::mul:
+                        UBINOP(*);
+                        break;
+                case DW_OP::neg:
+                        CHECK();
+                        tmp1.u = stack.back();
+                        tmp1.s = -tmp1.s;
+                        stack.back() = tmp1.u;
+                        break;
+                case DW_OP::not_:
+                        CHECK();
+                        stack.back() = ~stack.back();
+                        break;
+                case DW_OP::or_:
+                        UBINOP(|);
+                        break;
+                case DW_OP::plus:
+                        UBINOP(+);
+                        break;
+                case DW_OP::plus_uconst:
+                        tmp1.u = cur.uleb128();
+                        CHECK();
+                        stack.back() += tmp1.u;
+                        break;
+                case DW_OP::shl:
+                        CHECKN(2);
+                        tmp1.u = stack.back();
+                        stack.pop_back();
+                        tmp2.u = stack.back();
+                        // C++ does not define what happens if you
+                        // shift by more bits than the width of the
+                        // type, so we handle this case specially
+                        if (tmp1.u < sizeof(tmp2.u)*8)
+                                stack.back() = tmp2.u << tmp1.u;
+                        else
+                                stack.back() = 0;
+                        break;
+                case DW_OP::shr:
+                        CHECKN(2);
+                        tmp1.u = stack.back();
+                        stack.pop_back();
+                        tmp2.u = stack.back();
+                        // Same as above
+                        if (tmp1.u < sizeof(tmp2.u)*8)
+                                stack.back() = tmp2.u >> tmp1.u;
+                        else
+                                stack.back() = 0;
+                        break;
+                case DW_OP::shra:
+                        CHECKN(2);
+                        tmp1.u = stack.back();
+                        stack.pop_back();
+                        tmp2.u = stack.back();
+                        // Shifting a negative number is
+                        // implementation-defined in C++.
+                        tmp3.u = (tmp2.s < 0);
+                        if (tmp3.u)
+                                tmp2.s = -tmp2.s;
+                        if (tmp1.u < sizeof(tmp2.u)*8)
+                                tmp2.u >>= tmp1.u;
+                        else
+                                tmp2.u = 0;
+                        // DWARF implies that over-shifting a negative
+                        // number should result in 0, not ~0.
+                        if (tmp3.u)
+                                tmp2.s = -tmp2.s;
+                        stack.back() = tmp2.u;
+                        break;
+                case DW_OP::xor_:
+                        UBINOP(^);
+                        break;
+#undef UBINOP
+
+                        // 2.5.1.5 Control flow operations
+#define SRELOP(relop)                                                   \
+                        do {                                            \
+                                CHECKN(2);                              \
+                                tmp1.u = stack.back();                  \
+                                stack.pop_back();                       \
+                                tmp2.u = stack.back();                  \
+                                stack.back() = (tmp2.s <= tmp1.s) ? 1 : 0; \
+                        } while (0)
+                case DW_OP::le:
+                        SRELOP(<=);
+                        break;
+                case DW_OP::ge:
+                        SRELOP(>=);
+                        break;
+                case DW_OP::eq:
+                        SRELOP(==);
+                        break;
+                case DW_OP::lt:
+                        SRELOP(<);
+                        break;
+                case DW_OP::gt:
+                        SRELOP(>);
+                        break;
+                case DW_OP::ne:
+                        SRELOP(!=);
+                        break;
+                case DW_OP::skip:
+                        tmp1.s = cur.fixed<int16_t>();
+                        goto skip_common;
+                case DW_OP::bra:
+                        tmp1.s = cur.fixed<int16_t>();
+                        CHECK();
+                        tmp2.u = stack.back();
+                        stack.pop_back();
+                        if (tmp2.u == 0)
+                                break;
+                skip_common:
+                        cur = cursor(subsec, (int64_t)cur.get_section_offset() + tmp1.s);
+                        break;
+                case DW_OP::call2:
+                case DW_OP::call4:
+                case DW_OP::call_ref:
+                        // XXX
+                        throw runtime_error(to_string(op) + " not implemented");
+#undef SRELOP
+
+                        // 2.5.1.6 Special operations
+                case DW_OP::nop:
+                        break;
+
+                        // 2.6.1.1.2 Register location descriptions
+                case DW_OP::reg0...DW_OP::reg31:
+                        result.location_type = expr_result::type::reg;
+                        result.value = (unsigned)op - (unsigned)DW_OP::reg0;
+                        break;
+                case DW_OP::regx:
+                        result.location_type = expr_result::type::reg;
+                        result.value = cur.uleb128();
+                        break;
+
+                        // 2.6.1.1.3 Implicit location descriptions
+                case DW_OP::implicit_value:
+                        result.location_type = expr_result::type::implicit;
+                        result.implicit_len = cur.uleb128();
+                        cur.ensure(result.implicit_len);
+                        result.implicit = cur.pos;
+                        break;
+                case DW_OP::stack_value:
+                        CHECK();
+                        result.location_type = expr_result::type::literal;
+                        result.value = stack.back();
+                        break;
+
+                        // 2.6.1.2 Composite location descriptions
+                case DW_OP::piece:
+                case DW_OP::bit_piece:
+                        // XXX
+                        throw runtime_error(to_string(op) + " not implemented");
+
+                case DW_OP::lo_user...DW_OP::hi_user:
+                        // XXX We could let the context evaluate this,
+                        // but it would need access to the cursor.
+                        throw expr_error("unknown user op " + to_string(op));
+
+                default:
+                        throw expr_error("bad operation " + to_string(op));
+                }
+#pragma GCC diagnostic pop
+#undef CHECK
+#undef CHECKN
+        }
+
+        if (result.location_type == expr_result::type::address) {
+                // The result type is still and address, so we should
+                // fetch it from the top of stack.
+                if (stack.empty())
+                        throw expr_error("final stack is empty; no result given");
+                result.value = stack.back();
+        }
+
+        return result;
+
+underflow:
+        throw expr_error("stack underflow evaluating DWARF expression");
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/internal.hh

@@ -0,0 +1,297 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#ifndef _DWARFPP_INTERNAL_HH_
+#define _DWARFPP_INTERNAL_HH_
+
+#include "dwarf++.hh"
+#include "../elf/to_hex.hh"
+
+#include <stdexcept>
+#include <type_traits>
+#include <unordered_map>
+#include <vector>
+
+DWARFPP_BEGIN_NAMESPACE
+
+enum class format
+{
+        unknown,
+        dwarf32,
+        dwarf64
+};
+
+enum class byte_order
+{
+        lsb,
+        msb
+};
+
+/**
+ * Return this system's native byte order.
+ */
+static inline byte_order
+native_order()
+{
+        static const union
+        {
+                int i;
+                char c[sizeof(int)];
+        } test = {1};
+
+        return test.c[0] == 1 ? byte_order::lsb : byte_order::msb;
+}
+
+/**
+ * A single DWARF section or a slice of a section.  This also tracks
+ * dynamic information necessary to decode values in this section.
+ */
+struct section
+{
+        section_type type;
+        const char *begin, *end;
+        const format fmt;
+        const byte_order ord;
+        unsigned addr_size;
+
+        section(section_type type, const void *begin,
+                section_length length,
+                byte_order ord, format fmt = format::unknown,
+                unsigned addr_size = 0)
+                : type(type), begin((char*)begin), end((char*)begin + length),
+                  fmt(fmt), ord(ord), addr_size(addr_size) { }
+
+        section(const section &o) = default;
+
+        std::shared_ptr<section> slice(section_offset start, section_length len,
+                                       format fmt = format::unknown,
+                                       unsigned addr_size = 0)
+        {
+                if (fmt == format::unknown)
+                        fmt = this->fmt;
+                if (addr_size == 0)
+                        addr_size = this->addr_size;
+
+                return std::make_shared<section>(
+                        type, begin+start,
+                        std::min(len, (section_length)(end-begin)),
+                        ord, fmt, addr_size);
+        }
+
+        size_t size() const
+        {
+                return end - begin;
+        }
+};
+
+/**
+ * A cursor pointing into a DWARF section.  Provides deserialization
+ * operations and bounds checking.
+ */
+struct cursor
+{
+        // XXX There's probably a lot of overhead to maintaining the
+        // shared pointer to the section from this.  Perhaps the rule
+        // should be that all objects keep the dwarf::impl alive
+        // (directly or indirectly) and that keeps the loader alive,
+        // so a cursor just needs a regular section*.
+
+        std::shared_ptr<section> sec;
+        const char *pos;
+
+        cursor()
+                : pos(nullptr) { }
+        cursor(const std::shared_ptr<section> sec, section_offset offset = 0)
+                : sec(sec), pos(sec->begin + offset) { }
+
+        /**
+         * Read a subsection.  The cursor must be at an initial
+         * length.  After, the cursor will point just past the end of
+         * the subsection.  The returned section has the appropriate
+         * DWARF format and begins at the current location of the
+         * cursor (so this is usually followed by a
+         * skip_initial_length).
+         */
+        std::shared_ptr<section> subsection();
+        std::int64_t sleb128();
+        section_offset offset();
+        void string(std::string &out);
+        const char *cstr(size_t *size_out = nullptr);
+
+        void
+        ensure(section_offset bytes)
+        {
+                if ((section_offset)(sec->end - pos) < bytes || pos >= sec->end)
+                        underflow();
+        }
+
+        template<typename T>
+        T fixed()
+        {
+                ensure(sizeof(T));
+                static_assert(sizeof(T) <= 8, "T too big");
+                uint64_t val = 0;
+                const unsigned char *p = (const unsigned char*)pos;
+                if (sec->ord == byte_order::lsb) {
+                        for (unsigned i = 0; i < sizeof(T); i++)
+                                val |= ((uint64_t)p[i]) << (i * 8);
+                } else {
+                        for (unsigned i = 0; i < sizeof(T); i++)
+                                val = (val << 8) | (uint64_t)p[i];
+                }
+                pos += sizeof(T);
+                return (T)val;
+        }
+
+        std::uint64_t uleb128()
+        {
+                // Appendix C
+                // XXX Pre-compute all two byte ULEB's
+                std::uint64_t result = 0;
+                int shift = 0;
+                while (pos < sec->end) {
+                        uint8_t byte = *(uint8_t*)(pos++);
+                        result |= (uint64_t)(byte & 0x7f) << shift;
+                        if ((byte & 0x80) == 0)
+                                return result;
+                        shift += 7;
+                }
+                underflow();
+                return 0;
+        }
+
+        taddr address()
+        {
+                switch (sec->addr_size) {
+                case 1:
+                        return fixed<uint8_t>();
+                case 2:
+                        return fixed<uint16_t>();
+                case 4:
+                        return fixed<uint32_t>();
+                case 8:
+                        return fixed<uint64_t>();
+                default:
+                        throw std::runtime_error("address size " + std::to_string(sec->addr_size) + " not supported");
+                }
+        }
+
+        void skip_initial_length();
+        void skip_unit_type();
+        void skip_form(DW_FORM form);
+
+        cursor &operator+=(section_offset offset)
+        {
+                pos += offset;
+                return *this;
+        }
+
+        cursor operator+(section_offset offset) const
+        {
+                return cursor(sec, pos + offset);
+        }
+
+        bool operator<(const cursor &o) const
+        {
+                return pos < o.pos;
+        }
+
+        bool end() const
+        {
+                return pos >= sec->end;
+        }
+
+        bool valid() const
+        {
+                return !!pos;
+        }
+
+        section_offset get_section_offset() const
+        {
+                return pos - sec->begin;
+        }
+
+private:
+        cursor(const std::shared_ptr<section> sec, const char *pos)
+                : sec(sec), pos(pos) { }
+
+        void underflow();
+};
+
+/**
+ * An attribute specification in an abbrev.
+ */
+struct attribute_spec
+{
+        DW_AT name;
+        DW_FORM form;
+
+        // Computed information
+        value::type type;
+
+        attribute_spec(DW_AT name, DW_FORM form);
+};
+
+typedef std::uint64_t abbrev_code;
+
+/**
+ * An entry in .debug_abbrev.
+ */
+struct abbrev_entry
+{
+        abbrev_code code;
+        DW_TAG tag;
+        bool children;
+        std::vector<attribute_spec> attributes;
+
+        abbrev_entry() : code(0) { }
+
+        bool read(cursor *cur);
+};
+
+/**
+ * A section header in .debug_pubnames or .debug_pubtypes.
+ */
+struct name_unit
+{
+        uhalf version;
+        section_offset debug_info_offset;
+        section_length debug_info_length;
+        // Cursor to the first name_entry in this unit.  This cursor's
+        // section is limited to this unit.
+        cursor entries;
+
+        void read(cursor *cur)
+        {
+                // Section 7.19
+                std::shared_ptr<section> subsec = cur->subsection();
+                cursor sub(subsec);
+                sub.skip_initial_length();
+                version = sub.fixed<uhalf>();
+                if (version != 2)
+                        throw format_error("unknown name unit version " + std::to_string(version));
+                debug_info_offset = sub.offset();
+                debug_info_length = sub.offset();
+                entries = sub;
+        }
+};
+
+/**
+ * An entry in a .debug_pubnames or .debug_pubtypes unit.
+ */
+struct name_entry
+{
+        section_offset offset;
+        std::string name;
+
+        void read(cursor *cur)
+        {
+                offset = cur->offset();
+                cur->string(name);
+        }
+};
+
+DWARFPP_END_NAMESPACE
+
+#endif

3party/libelfin/dwarf/line.cc

@@ -0,0 +1,438 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+#include <cassert>
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+// The expected number of arguments for standard opcodes.  This is
+// used to check the opcode_lengths header field for compatibility.
+static const int opcode_lengths[] = {
+        0,
+        // DW_LNS::copy
+        0, 1, 1, 1, 1,
+        // DW_LNS::negate_stmt
+        0, 0, 0, 1, 0,
+        // DW_LNS::set_epilogue_begin
+        0, 1
+};
+
+struct line_table::impl
+{
+        shared_ptr<section> sec;
+
+        // Header information
+        section_offset program_offset;
+        ubyte minimum_instruction_length;
+        ubyte maximum_operations_per_instruction;
+        bool default_is_stmt;
+        sbyte line_base;
+        ubyte line_range;
+        ubyte opcode_base;
+        vector<ubyte> standard_opcode_lengths;
+        vector<string> include_directories;
+        vector<file> file_names;
+
+        // The offset in sec following the last read file name entry.
+        // File name entries can appear both in the line table header
+        // and in the line number program itself.  Since we can
+        // iterate over the line number program repeatedly, this keeps
+        // track of how far we've gotten so we don't add the same
+        // entry twice.
+        section_offset last_file_name_end;
+        // If an iterator has traversed the entire program, then we
+        // know we've gathered all file names.
+        bool file_names_complete;
+
+        impl() : last_file_name_end(0), file_names_complete(false) {};
+
+        bool read_file_entry(cursor *cur, bool in_header);
+};
+
+line_table::line_table(const shared_ptr<section> &sec, section_offset offset,
+                       unsigned cu_addr_size, const string &cu_comp_dir,
+                       const string &cu_name)
+        : m(make_shared<impl>())
+{
+        // XXX DWARF2 and 3 give a weird specification for DW_AT_comp_dir
+
+        string comp_dir, abs_path;
+        if (cu_comp_dir.empty() || cu_comp_dir.back() == '/')
+                comp_dir = cu_comp_dir;
+        else
+                comp_dir = cu_comp_dir + '/';
+
+        // Read the line table header (DWARF2 section 6.2.4, DWARF3
+        // section 6.2.4, DWARF4 section 6.2.3)
+        cursor cur(sec, offset);
+        m->sec = cur.subsection();
+        cur = cursor(m->sec);
+        cur.skip_initial_length();
+        m->sec->addr_size = cu_addr_size;
+
+        // Basic header information
+        uhalf version = cur.fixed<uhalf>();
+        if (version < 2 || version > 4)
+                throw format_error("unknown line number table version " +
+                                   std::to_string(version));
+        section_length header_length = cur.offset();
+        m->program_offset = cur.get_section_offset() + header_length;
+        m->minimum_instruction_length = cur.fixed<ubyte>();
+        m->maximum_operations_per_instruction = 1;
+        if (version >= 4)
+                m->maximum_operations_per_instruction = cur.fixed<ubyte>();
+        if (m->maximum_operations_per_instruction == 0)
+                throw format_error("maximum_operations_per_instruction cannot"
+                                   " be 0 in line number table");
+        m->default_is_stmt = cur.fixed<ubyte>();
+        m->line_base = cur.fixed<sbyte>();
+        m->line_range = cur.fixed<ubyte>();
+        if (m->line_range == 0)
+                throw format_error("line_range cannot be 0 in line number table");
+        m->opcode_base = cur.fixed<ubyte>();
+        
+        static_assert(sizeof(opcode_lengths) / sizeof(opcode_lengths[0]) == 13,
+                      "opcode_lengths table has wrong length");
+
+        // Opcode length table
+        m->standard_opcode_lengths.resize(m->opcode_base);
+        m->standard_opcode_lengths[0] = 0;
+        for (unsigned i = 1; i < m->opcode_base; i++) {
+                ubyte length = cur.fixed<ubyte>();
+                if (length != opcode_lengths[i])
+                        // The spec never says what to do if the
+                        // opcode length of a standard opcode doesn't
+                        // match the header.  Do the safe thing.
+                        throw format_error(
+                                "expected " +
+                                std::to_string(opcode_lengths[i]) +
+                                " arguments for line number opcode " +
+                                std::to_string(i) + ", got " +
+                                std::to_string(length));
+                m->standard_opcode_lengths[i] = length;
+        }
+
+        // Include directories list
+        string incdir;
+        // Include directory 0 is implicitly the compilation unit
+        // current directory
+        m->include_directories.push_back(comp_dir);
+        while (true) {
+                cur.string(incdir);
+                if (incdir.empty())
+                        break;
+                if (incdir.back() != '/')
+                        incdir += '/';
+                if (incdir[0] == '/')
+                        m->include_directories.push_back(move(incdir));
+                else
+                        m->include_directories.push_back(comp_dir + incdir);
+        }
+
+        // File name list
+        string file_name;
+        // File name 0 is implicitly the compilation unit file name.
+        // cu_name can be relative to comp_dir or absolute.
+        if (!cu_name.empty() && cu_name[0] == '/')
+                m->file_names.emplace_back(cu_name);
+        else
+                m->file_names.emplace_back(comp_dir + cu_name);
+        while (m->read_file_entry(&cur, true));
+}
+
+line_table::iterator
+line_table::begin() const
+{
+        if (!valid())
+                return iterator(nullptr, 0);
+        return iterator(this, m->program_offset);
+}
+
+line_table::iterator
+line_table::end() const
+{
+        if (!valid())
+                return iterator(nullptr, 0);
+        return iterator(this, m->sec->size());
+}
+
+line_table::iterator
+line_table::find_address(taddr addr) const
+{
+        iterator prev = begin(), e = end();
+        if (prev == e)
+                return prev;
+
+        iterator it = prev;
+        for (++it; it != e; prev = it++) {
+                if (prev->address <= addr && it->address > addr &&
+                    !prev->end_sequence)
+                        return prev;
+        }
+        prev = e;
+        return prev;
+}
+
+const line_table::file *
+line_table::get_file(unsigned index) const
+{
+        if (index >= m->file_names.size()) {
+                // It could be declared in the line table program.
+                // This is unlikely, so we don't have to be
+                // super-efficient about this.  Just force our way
+                // through the whole line table program.
+                if (!m->file_names_complete) {
+                        for (auto &ent : *this)
+                                (void)ent;
+                }
+                if (index >= m->file_names.size())
+                        throw out_of_range
+                                ("file name index " + std::to_string(index) +
+                                 " exceeds file table size of " +
+                                 std::to_string(m->file_names.size()));
+        }
+        return &m->file_names[index];
+}
+
+bool
+line_table::impl::read_file_entry(cursor *cur, bool in_header)
+{
+        assert(cur->sec == sec);
+
+        string file_name;
+        cur->string(file_name);
+        if (in_header && file_name.empty())
+                return false;
+        uint64_t dir_index = cur->uleb128();
+        uint64_t mtime = cur->uleb128();
+        uint64_t length = cur->uleb128();
+
+        // Have we already processed this file entry?
+        if (cur->get_section_offset() <= last_file_name_end)
+                return true;
+        last_file_name_end = cur->get_section_offset();
+
+        if (file_name[0] == '/')
+                file_names.emplace_back(move(file_name), mtime, length);
+        else if (dir_index < include_directories.size())
+                file_names.emplace_back(
+                        include_directories[dir_index] + file_name,
+                        mtime, length);
+        else
+                throw format_error("file name directory index out of range: " +
+                                   std::to_string(dir_index));
+
+        return true;
+}
+
+line_table::file::file(string path, uint64_t mtime, uint64_t length)
+        : path(path), mtime(mtime), length(length)
+{
+}
+
+void
+line_table::entry::reset(bool is_stmt)
+{
+        address = op_index = 0;
+        file = nullptr;
+        file_index = line = 1;
+        column = 0;
+        this->is_stmt = is_stmt;
+        basic_block = end_sequence = prologue_end = epilogue_begin = false;
+        isa = discriminator = 0;
+}
+
+string
+line_table::entry::get_description() const
+{
+        string res = file->path;
+        if (line) {
+                res.append(":").append(std::to_string(line));
+                if (column)
+                        res.append(":").append(std::to_string(column));
+        }
+        return res;
+}
+
+line_table::iterator::iterator(const line_table *table, section_offset pos)
+        : table(table), pos(pos)
+{
+        if (table) {
+                regs.reset(table->m->default_is_stmt);
+                ++(*this);
+        }
+}
+
+line_table::iterator &
+line_table::iterator::operator++()
+{
+        cursor cur(table->m->sec, pos);
+
+        // Execute opcodes until we reach the end of the stream or an
+        // opcode emits a line table row
+        bool stepped = false, output = false;
+        while (!cur.end() && !output) {
+                output = step(&cur);
+                stepped = true;
+        }
+        if (stepped && !output)
+                throw format_error("unexpected end of line table");
+        if (stepped && cur.end()) {
+                // Record that all file names must be known now
+                table->m->file_names_complete = true;
+        }
+        if (output) {
+                // Resolve file name of entry
+                if (entry.file_index < table->m->file_names.size())
+                        entry.file = &table->m->file_names[entry.file_index];
+                else
+                        throw format_error("bad file index " +
+                                           std::to_string(entry.file_index) +
+                                           " in line table");
+        }
+
+        pos = cur.get_section_offset();
+        return *this;
+}
+
+bool
+line_table::iterator::step(cursor *cur)
+{
+        struct line_table::impl *m = table->m.get();
+
+        // Read the opcode (DWARF4 section 6.2.3)
+        ubyte opcode = cur->fixed<ubyte>();
+        if (opcode >= m->opcode_base) {
+                // Special opcode (DWARF4 section 6.2.5.1)
+                ubyte adjusted_opcode = opcode - m->opcode_base;
+                unsigned op_advance = adjusted_opcode / m->line_range;
+                signed line_inc = m->line_base + (signed)adjusted_opcode % m->line_range;
+
+                regs.line += line_inc;
+                regs.address += m->minimum_instruction_length *
+                        ((regs.op_index + op_advance)
+                         / m->maximum_operations_per_instruction);
+                regs.op_index = (regs.op_index + op_advance)
+                        % m->maximum_operations_per_instruction;
+                entry = regs;
+
+                regs.basic_block = regs.prologue_end =
+                        regs.epilogue_begin = false;
+                regs.discriminator = 0;
+
+                return true;
+        } else if (opcode != 0) {
+                // Standard opcode (DWARF4 sections 6.2.3 and 6.2.5.2)
+                //
+                // According to the standard, any opcode between the
+                // highest defined opcode for a given DWARF version
+                // and opcode_base should be treated as a
+                // vendor-specific opcode. However, the de facto
+                // standard seems to be to process these as standard
+                // opcodes even if they're from a later version of the
+                // standard than the line table header claims.
+                uint64_t uarg;
+#pragma GCC diagnostic push
+#pragma GCC diagnostic warning "-Wswitch-enum"
+                switch ((DW_LNS)opcode) {
+                case DW_LNS::copy:
+                        entry = regs;
+                        regs.basic_block = regs.prologue_end =
+                                regs.epilogue_begin = false;
+                        regs.discriminator = 0;
+                        break;
+                case DW_LNS::advance_pc:
+                        // Opcode advance (as for special opcodes)
+                        uarg = cur->uleb128();
+                advance_pc:
+                        regs.address += m->minimum_instruction_length *
+                                ((regs.op_index + uarg)
+                                 / m->maximum_operations_per_instruction);
+                        regs.op_index = (regs.op_index + uarg)
+                                % m->maximum_operations_per_instruction;
+                        break;
+                case DW_LNS::advance_line:
+                        regs.line = (signed)regs.line + cur->sleb128();
+                        break;
+                case DW_LNS::set_file:
+                        regs.file_index = cur->uleb128();
+                        break;
+                case DW_LNS::set_column:
+                        regs.column = cur->uleb128();
+                        break;
+                case DW_LNS::negate_stmt:
+                        regs.is_stmt = !regs.is_stmt;
+                        break;
+                case DW_LNS::set_basic_block:
+                        regs.basic_block = true;
+                        break;
+                case DW_LNS::const_add_pc:
+                        uarg = (255 - m->opcode_base) / m->line_range;
+                        goto advance_pc;
+                case DW_LNS::fixed_advance_pc:
+                        regs.address += cur->fixed<uhalf>();
+                        regs.op_index = 0;
+                        break;
+                case DW_LNS::set_prologue_end:
+                        regs.prologue_end = true;
+                        break;
+                case DW_LNS::set_epilogue_begin:
+                        regs.epilogue_begin = true;
+                        break;
+                case DW_LNS::set_isa:
+                        regs.isa = cur->uleb128();
+                        break;
+                default:
+                        // XXX Vendor extensions
+                        throw format_error("unknown line number opcode " +
+                                           to_string((DW_LNS)opcode));
+                }
+                return ((DW_LNS)opcode == DW_LNS::copy);
+        } else { // opcode == 0
+                // Extended opcode (DWARF4 sections 6.2.3 and 6.2.5.3)
+                assert(opcode == 0);
+                uint64_t length = cur->uleb128();
+                section_offset end = cur->get_section_offset() + length;
+                opcode = cur->fixed<ubyte>();
+                switch ((DW_LNE)opcode) {
+                case DW_LNE::end_sequence:
+                        regs.end_sequence = true;
+                        entry = regs;
+                        regs.reset(m->default_is_stmt);
+                        break;
+                case DW_LNE::set_address:
+                        regs.address = cur->address();
+                        regs.op_index = 0;
+                        break;
+                case DW_LNE::define_file:
+                        m->read_file_entry(cur, false);
+                        break;
+                case DW_LNE::set_discriminator:
+                        // XXX Only DWARF4
+                        regs.discriminator = cur->uleb128();
+                        break;
+                case DW_LNE::lo_user...DW_LNE::hi_user:
+                        // XXX Vendor extensions
+                        throw runtime_error("vendor line number opcode " +
+                                            to_string((DW_LNE)opcode) +
+                                            " not implemented");
+                default:
+                        // XXX Prior to DWARF4, any opcode number
+                        // could be a vendor extension
+                        throw format_error("unknown line number opcode " +
+                                           to_string((DW_LNE)opcode));
+                }
+#pragma GCC diagnostic pop
+                if (cur->get_section_offset() > end)
+                        throw format_error("extended line number opcode exceeded its size");
+                cur += end - cur->get_section_offset();
+                return ((DW_LNE)opcode == DW_LNE::end_sequence);
+        }
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/rangelist.cc

@@ -0,0 +1,103 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+rangelist::rangelist(const std::shared_ptr<section> &sec, section_offset off,
+                     unsigned cu_addr_size, taddr cu_low_pc)
+        : sec(sec->slice(off, ~0, format::unknown, cu_addr_size)),
+          base_addr(cu_low_pc)
+{
+}
+
+rangelist::rangelist(const initializer_list<pair<taddr, taddr> > &ranges)
+{
+        synthetic.reserve(ranges.size() * 2 + 2);
+        for (auto &range : ranges) {
+                synthetic.push_back(range.first);
+                synthetic.push_back(range.second);
+        }
+        synthetic.push_back(0);
+        synthetic.push_back(0);
+
+        sec = make_shared<section>(
+                section_type::ranges, (const char*)synthetic.data(),
+                synthetic.size() * sizeof(taddr),
+                native_order(), format::unknown, sizeof(taddr));
+
+        base_addr = 0;
+}
+
+rangelist::iterator
+rangelist::begin() const
+{
+        if (sec)
+                return iterator(sec, base_addr);
+        return end();
+}
+
+rangelist::iterator
+rangelist::end() const
+{
+        return iterator();
+}
+
+bool
+rangelist::contains(taddr addr) const
+{
+        for (auto ent : *this)
+                if (ent.contains(addr))
+                        return true;
+        return false;
+}
+
+rangelist::iterator::iterator(const std::shared_ptr<section> &sec, taddr base_addr)
+        : sec(sec), base_addr(base_addr), pos(0)
+{
+        // Read in the first entry
+        ++(*this);
+}
+
+rangelist::iterator &
+rangelist::iterator::operator++()
+{
+        // DWARF4 section 2.17.3
+        taddr largest_offset = ~(taddr)0;
+        if (sec->addr_size < sizeof(taddr))
+                largest_offset += 1 << (8 * sec->addr_size);
+
+        // Read in entries until we reach a regular entry of an
+        // end-of-list.  Note that pos points to the beginning of the
+        // entry *following* the current entry, so that's where we
+        // start.
+        cursor cur(sec, pos);
+        while (true) {
+                entry.low = cur.address();
+                entry.high = cur.address();
+
+                if (entry.low == 0 && entry.high == 0) {
+                        // End of list
+                        sec.reset();
+                        pos = 0;
+                        break;
+                } else if (entry.low == largest_offset) {
+                        // Base address change
+                        base_addr = entry.high;
+                } else {
+                        // Regular entry.  Adjust by base address.
+                        entry.low += base_addr;
+                        entry.high += base_addr;
+                        pos = cur.get_section_offset();
+                        break;
+                }
+        }
+
+        return *this;
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/dwarf/small_vector.hh

@@ -0,0 +1,197 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#ifndef _DWARFPP_SMALL_VECTOR_HH_
+#define _DWARFPP_SMALL_VECTOR_HH_
+
+DWARFPP_BEGIN_NAMESPACE
+
+/**
+ * A vector-like class that only heap allocates above a specified
+ * size.
+ */
+template<class T, unsigned Min>
+class small_vector
+{
+public:
+        typedef T value_type;
+        typedef value_type& reference;
+        typedef const value_type& const_reference;
+        typedef size_t size_type;
+
+        small_vector()
+                : base((T*)buf), end(base), cap((T*)&buf[sizeof(T[Min])])
+        {
+        }
+
+        small_vector(const small_vector<T, Min> &o)
+                : base((T*)buf), end(base), cap((T*)&buf[sizeof(T[Min])])
+        {
+                *this = o;
+        }
+
+        small_vector(small_vector<T, Min> &&o)
+                : base((T*)buf), end(base), cap((T*)&buf[sizeof(T[Min])])
+        {
+                if ((char*)o.base == o.buf) {
+                        // Elements are inline; have to copy them
+                        base = (T*)buf;
+                        end = base;
+                        cap = (T*)&buf[sizeof(T[Min])];
+
+                        *this = o;
+                        o.clear();
+                } else {
+                        // Elements are external; swap pointers
+                        base = o.base;
+                        end = o.end;
+                        cap = o.cap;
+
+                        o.base = (T*)o.buf;
+                        o.end = o.base;
+                        o.cap = (T*)&o.buf[sizeof(T[Min])];
+                }
+        }
+
+        ~small_vector()
+        {
+                clear();
+                if ((char*)base != buf)
+                        delete[] (char*)base;
+        }
+
+        small_vector &operator=(const small_vector<T, Min> &o)
+        {
+                size_type osize = o.size();
+                clear();
+                reserve(osize);
+                for (size_type i = 0; i < osize; i++)
+                        new (&base[i]) T(o[i]);
+                end = base + osize;
+                return *this;
+        }
+
+        size_type size() const
+        {
+                return end - base;
+        }
+
+        bool empty() const
+        {
+                return base == end;
+        }
+
+        void reserve(size_type n)
+        {
+                if (n <= (size_type)(cap - base))
+                        return;
+
+                size_type target = cap - base;
+                if (target == 0)
+                        target = 1;
+                while (target < n)
+                        target <<= 1;
+
+                char *newbuf = new char[sizeof(T[target])];
+                T *src = base, *dest = (T*)newbuf;
+                for (; src < end; src++, dest++) {
+                        new(dest) T(*src);
+                        dest->~T();
+                }
+                if ((char*)base != buf)
+                        delete[] (char*)base;
+                base = (T*)newbuf;
+                end = dest;
+                cap = base + target;
+        }
+
+        reference operator[](size_type n)
+        {
+                return base[n];
+        }
+
+        const_reference operator[](size_type n) const
+        {
+                return base[n];
+        }
+
+        reference at(size_type n)
+        {
+                return base[n];
+        }
+
+        const_reference at(size_type n) const
+        {
+                return base[n];
+        }
+
+        /**
+         * "Reverse at".  revat(0) is equivalent to back().  revat(1)
+         * is the element before back.  Etc.
+         */
+        reference revat(size_type n)
+        {
+                return *(end - 1 - n);
+        }
+
+        const_reference revat(size_type n) const
+        {
+                return *(end - 1 - n);
+        }
+
+        reference front()
+        {
+                return base[0];
+        }
+
+        const_reference front() const
+        {
+                return base[0];
+        }
+
+        reference back()
+        {
+                return *(end-1);
+        }
+
+        const_reference back() const
+        {
+                return *(end-1);
+        }
+
+        void push_back(const T& x)
+        {
+                reserve(size() + 1);
+                new (end) T(x);
+                end++;
+        }
+
+        void push_back(T&& x)
+        {
+                reserve(size() + 1);
+                new (end) T(std::move(x));
+                end++;
+        }
+
+        void pop_back()
+        {
+                end--;
+                end->~T();
+        }
+
+        void clear()
+        {
+                for (T* p = base; p < end; ++p)
+                        p->~T();
+                end = base;
+        }
+
+private:
+        char buf[sizeof(T[Min])];
+        T *base, *end, *cap;
+};
+
+DWARFPP_END_NAMESPACE
+
+#endif

3party/libelfin/dwarf/value.cc

@@ -0,0 +1,336 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "internal.hh"
+
+#include <cstring>
+
+using namespace std;
+
+DWARFPP_BEGIN_NAMESPACE
+
+value::value(const unit *cu,
+             DW_AT name, DW_FORM form, type typ, section_offset offset)
+        : cu(cu), form(form), typ(typ), offset(offset) {
+        if (form == DW_FORM::indirect)
+                resolve_indirect(name);
+}
+
+section_offset
+value::get_section_offset() const
+{
+        return cu->get_section_offset() + offset;
+}
+
+taddr
+value::as_address() const
+{
+        if (form != DW_FORM::addr)
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as address");
+
+        cursor cur(cu->data(), offset);
+        return cur.address();
+}
+
+const void *
+value::as_block(size_t *size_out) const
+{
+        // XXX Blocks can contain all sorts of things, including
+        // references, which couldn't be resolved by callers in the
+        // current minimal API.
+        cursor cur(cu->data(), offset);
+        switch (form) {
+        case DW_FORM::block1:
+                *size_out = cur.fixed<uint8_t>();
+                break;
+        case DW_FORM::block2:
+                *size_out = cur.fixed<uint16_t>();
+                break;
+        case DW_FORM::block4:
+                *size_out = cur.fixed<uint32_t>();
+                break;
+        case DW_FORM::block:
+        case DW_FORM::exprloc:
+                *size_out = cur.uleb128();
+                break;
+        default:
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as block");
+        }
+        cur.ensure(*size_out);
+        return cur.pos;
+}
+
+uint64_t
+value::as_uconstant() const
+{
+        cursor cur(cu->data(), offset);
+        switch (form) {
+        case DW_FORM::data1:
+                return cur.fixed<uint8_t>();
+        case DW_FORM::data2:
+                return cur.fixed<uint16_t>();
+        case DW_FORM::data4:
+                return cur.fixed<uint32_t>();
+        case DW_FORM::data8:
+                return cur.fixed<uint64_t>();
+        case DW_FORM::udata:
+                return cur.uleb128();
+        default:
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as uconstant");
+        }
+}
+
+int64_t
+value::as_sconstant() const
+{
+        cursor cur(cu->data(), offset);
+        switch (form) {
+        case DW_FORM::data1:
+                return cur.fixed<int8_t>();
+        case DW_FORM::data2:
+                return cur.fixed<int16_t>();
+        case DW_FORM::data4:
+                return cur.fixed<int32_t>();
+        case DW_FORM::data8:
+                return cur.fixed<int64_t>();
+        case DW_FORM::sdata:
+                return cur.sleb128();
+        default:
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as sconstant");
+        }
+}
+
+expr
+value::as_exprloc() const
+{
+        cursor cur(cu->data(), offset);
+        size_t size;
+        // Prior to DWARF 4, exprlocs were encoded as blocks.
+        switch (form) {
+        case DW_FORM::exprloc:
+        case DW_FORM::block:
+                size = cur.uleb128();
+                break;
+        case DW_FORM::block1:
+                size = cur.fixed<uint8_t>();
+                break;
+        case DW_FORM::block2:
+                size = cur.fixed<uint16_t>();
+                break;
+        case DW_FORM::block4:
+                size = cur.fixed<uint32_t>();
+                break;
+        default:
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as exprloc");
+        }
+        return expr(cu, cur.get_section_offset(), size);
+}
+
+bool
+value::as_flag() const
+{
+        switch (form) {
+        case DW_FORM::flag: {
+                cursor cur(cu->data(), offset);
+                return cur.fixed<ubyte>() != 0;
+        }
+        case DW_FORM::flag_present:
+                return true;
+        default:
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as flag");
+        }
+}
+
+rangelist
+value::as_rangelist() const
+{
+        section_offset off = as_sec_offset();
+
+        // The compilation unit may not have a base address.  In this
+        // case, the first entry in the range list must be a base
+        // address entry, but we'll just assume 0 for the initial base
+        // address.
+        die cudie = cu->root();
+        taddr cu_low_pc = cudie.has(DW_AT::low_pc) ? at_low_pc(cudie) : 0;
+        auto sec = cu->get_dwarf().get_section(section_type::ranges);
+        auto cusec = cu->data();
+        return rangelist(sec, off, cusec->addr_size, cu_low_pc);
+}
+
+die
+value::as_reference() const
+{
+        section_offset off;
+        // XXX Would be nice if we could avoid this.  The cursor is
+        // all overhead here.
+        cursor cur(cu->data(), offset);
+        switch (form) {
+        case DW_FORM::ref1:
+                off = cur.fixed<ubyte>();
+                break;
+        case DW_FORM::ref2:
+                off = cur.fixed<uhalf>();
+                break;
+        case DW_FORM::ref4:
+                off = cur.fixed<uword>();
+                break;
+        case DW_FORM::ref8:
+                off = cur.fixed<uint64_t>();
+                break;
+        case DW_FORM::ref_udata:
+                off = cur.uleb128();
+                break;
+
+        case DW_FORM::ref_addr: {
+                off = cur.offset();
+                // These seem to be extremely rare in practice (I
+                // haven't been able to get gcc to produce a
+                // ref_addr), so it's not worth caching this lookup.
+                const compilation_unit *base_cu = nullptr;
+                for (auto &file_cu : cu->get_dwarf().compilation_units()) {
+                        if (file_cu.get_section_offset() > off)
+                                break;
+                        base_cu = &file_cu;
+                }
+                die d(base_cu);
+                d.read(off - base_cu->get_section_offset());
+                return d;
+        }
+
+        case DW_FORM::ref_sig8: {
+                uint64_t sig = cur.fixed<uint64_t>();
+                try {
+                        return cu->get_dwarf().get_type_unit(sig).type();
+                } catch (std::out_of_range &e) {
+                        throw format_error("unknown type signature 0x" + to_hex(sig));
+                }
+        }
+
+        default:
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as reference");
+        }
+
+        die d(cu);
+        d.read(off);
+        return d;
+}
+
+void
+value::as_string(string &buf) const
+{
+        size_t size;
+        const char *p = as_cstr(&size);
+        buf.resize(size);
+        memmove(&buf.front(), p, size);
+}
+
+string
+value::as_string() const
+{
+        size_t size;
+        const char *s = as_cstr(&size);
+        return string(s, size);
+}
+
+const char *
+value::as_cstr(size_t *size_out) const
+{
+        cursor cur(cu->data(), offset);
+        switch (form) {
+        case DW_FORM::string:
+                return cur.cstr(size_out);
+        case DW_FORM::strp: {
+                section_offset off = cur.offset();
+                cursor scur(cu->get_dwarf().get_section(section_type::str), off);
+                return scur.cstr(size_out);
+        }
+        default:
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as string");
+        }
+}
+
+section_offset
+value::as_sec_offset() const
+{
+        // Prior to DWARF 4, sec_offsets were encoded as data4 or
+        // data8.
+        cursor cur(cu->data(), offset);
+        switch (form) {
+        case DW_FORM::data4:
+                return cur.fixed<uint32_t>();
+        case DW_FORM::data8:
+                return cur.fixed<uint64_t>();
+        case DW_FORM::sec_offset:
+                return cur.offset();
+        default:
+                throw value_type_mismatch("cannot read " + to_string(typ) + " as sec_offset");
+        }
+}
+
+void
+value::resolve_indirect(DW_AT name)
+{
+        if (form != DW_FORM::indirect)
+                return;
+
+        cursor c(cu->data(), offset);
+        DW_FORM form;
+        do {
+                form = (DW_FORM)c.uleb128();
+        } while (form == DW_FORM::indirect);
+        typ = attribute_spec(name, form).type;
+        offset = c.get_section_offset();
+}
+
+string
+to_string(const value &v)
+{
+        switch (v.get_type()) {
+        case value::type::invalid:
+                return "<invalid value type>";
+        case value::type::address:
+                return "0x" + to_hex(v.as_address());
+        case value::type::block: {
+                size_t size;
+                const char *b = (const char*)v.as_block(&size);
+                string res = ::to_string(size) + " byte block:";
+                for (size_t pos = 0; pos < size; ++pos) {
+                        res += ' ';
+                        res += to_hex(b[pos]);
+                }
+                return res;
+        }
+        case value::type::constant:
+                return "0x" + to_hex(v.as_uconstant());
+        case value::type::uconstant:
+                return ::to_string(v.as_uconstant());
+        case value::type::sconstant:
+                return ::to_string(v.as_sconstant());
+        case value::type::exprloc:
+                // XXX
+                return "<exprloc>";
+        case value::type::flag:
+                return v.as_flag() ? "true" : "false";
+        case value::type::line:
+                return "<line 0x" + to_hex(v.as_sec_offset()) + ">";
+        case value::type::loclist:
+                return "<loclist 0x" + to_hex(v.as_sec_offset()) + ">";
+        case value::type::mac:
+                return "<mac 0x" + to_hex(v.as_sec_offset()) + ">";
+        case value::type::rangelist:
+                return "<rangelist 0x" + to_hex(v.as_sec_offset()) + ">";
+        case value::type::reference: {
+                die d = v.as_reference();
+                auto tu = dynamic_cast<const type_unit*>(&d.get_unit());
+                if (tu)
+                        return "<.debug_types+0x" + to_hex(d.get_section_offset()) + ">";
+                return "<0x" + to_hex(d.get_section_offset()) + ">";
+        }
+        case value::type::string:
+                return v.as_string();
+        }
+        return "<unexpected value type " + to_string(v.get_type()) + ">";
+}
+
+DWARFPP_END_NAMESPACE

3party/libelfin/elf/.gitignore

@@ -0,0 +1,6 @@
+*.o
+to_string.cc
+libelf++.a
+libelf++.so
+libelf++.so.*
+libelf++.pc

3party/libelfin/elf/common.hh

@@ -0,0 +1,109 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#ifndef _ELFPP_COMMON_HH_
+#define _ELFPP_COMMON_HH_
+
+#define ELFPP_BEGIN_NAMESPACE namespace elf {
+#define ELFPP_END_NAMESPACE   }
+#define ELFPP_BEGIN_INTERNAL  namespace internal {
+#define ELFPP_END_INTERNAL    }
+
+#include <cstdint>
+
+ELFPP_BEGIN_NAMESPACE
+
+/**
+ * A byte ordering.
+ */
+enum class byte_order
+{
+        native,
+        lsb,
+        msb
+};
+
+/**
+ * Return either byte_order::lsb or byte_order::msb.  If the argument
+ * is byte_order::native, it will be resolved to whatever the native
+ * byte order is.
+ */
+static inline byte_order
+resolve_order(byte_order o)
+{
+        static const union
+        {
+                int i;
+                char c[sizeof(int)];
+        } test = {1};
+
+        if (o == byte_order::native)
+                return test.c[0] == 1 ? byte_order::lsb : byte_order::msb;
+        return o;
+}
+
+/**
+ * Return v converted from one byte order to another.
+ */
+template<typename T>
+T
+swizzle(T v, byte_order from, byte_order to)
+{
+        static_assert(sizeof(T) == 1 ||
+                      sizeof(T) == 2 ||
+                      sizeof(T) == 4 ||
+                      sizeof(T) == 8,
+                      "cannot swizzle type");
+
+        from = resolve_order(from);
+        to = resolve_order(to);
+
+        if (from == to)
+                return v;
+
+        switch (sizeof(T)) {
+        case 1:
+                return v;
+        case 2: {
+                std::uint16_t x = (std::uint16_t)v;
+                return (T)(((x&0xFF) << 8) | (x >> 8));
+        }
+        case 4:
+                return (T)__builtin_bswap32((std::uint32_t)v);
+        case 8:
+                return (T)__builtin_bswap64((std::uint64_t)v);
+        }
+}
+
+ELFPP_BEGIN_INTERNAL
+
+/**
+ * OrderPick selects between Native, LSB, and MSB based on ord.
+ */
+template<byte_order ord, typename Native, typename LSB, typename MSB>
+struct OrderPick;
+
+template<typename Native, typename LSB, typename MSB>
+struct OrderPick<byte_order::native, Native, LSB, MSB>
+{
+        typedef Native T;
+};
+
+template<typename Native, typename LSB, typename MSB>
+struct OrderPick<byte_order::lsb, Native, LSB, MSB>
+{
+        typedef LSB T;
+};
+
+template<typename Native, typename LSB, typename MSB>
+struct OrderPick<byte_order::msb, Native, LSB, MSB>
+{
+        typedef MSB T;
+};
+
+ELFPP_END_INTERNAL
+
+ELFPP_END_NAMESPACE
+
+#endif

3party/libelfin/elf/data.hh

@@ -0,0 +1,574 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#ifndef _ELFPP_DATA_HH_
+#define _ELFPP_DATA_HH_
+
+#include "common.hh"
+
+#include <cstdint>
+#include <cstring>
+#include <string>
+
+ELFPP_BEGIN_NAMESPACE
+
+// Object file classes (ELF64 table 3)
+enum class elfclass : unsigned char
+{
+        _32 = 1,                // 32-bit objects
+        _64 = 2,                // 64-bit objects
+};
+
+std::string
+to_string(elfclass v);
+
+// Common basic data types
+struct ElfTypes
+{
+        typedef std::uint16_t Half;
+        typedef std::uint32_t Word;
+        typedef std::int32_t  Sword;
+};
+
+struct Elf32 : public ElfTypes
+{
+        // ELF class
+        static const elfclass cls = elfclass::_32;
+
+        // Basic data types (ELF32 figure 1-2)
+        typedef std::uint32_t Addr;
+        typedef std::uint32_t Off;
+
+        // Predicated types
+        typedef Word Word32_Xword64;
+
+        template<typename t32, typename t64>
+        struct pick
+        {
+                typedef t32 t;
+        };
+};
+
+struct Elf64 : ElfTypes
+{
+        // ELF class
+        static const elfclass cls = elfclass::_64;
+
+        // Basic data types (ELF64 table 1)
+        typedef std::uint64_t Addr;
+        typedef std::uint64_t Off;
+        typedef std::uint64_t Xword;
+        typedef std::int64_t  Sxword;
+
+        // Predicated types
+        typedef Xword Word32_Xword64;
+
+        template<typename t32, typename t64>
+        struct pick
+        {
+                typedef t64 t;
+        };
+};
+
+// Data encodings (ELF64 table 4)
+enum class elfdata : unsigned char
+{
+        lsb = 1,
+        msb = 2,
+};
+
+std::string
+to_string(elfdata v);
+
+// Operating system and ABI identifiers (ELF64 table 5)
+enum class elfosabi : unsigned char
+{
+        sysv = 0,
+        hpux = 1,
+        standalone = 255,
+};
+
+std::string
+to_string(elfosabi v);
+
+// Object file types (ELF64 table 6)
+enum class et : ElfTypes::Half
+{
+        none   = 0,             // No file type
+        rel    = 1,             // Relocatable object file
+        exec   = 2,             // Executable file
+        dyn    = 3,             // Shared object file
+        core   = 4,             // Core file
+        loos   = 0xfe00,        // Environment-specific use
+        hios   = 0xfeff,
+        loproc = 0xff00,        // Processor-specific use
+        hiproc = 0xffff,
+};
+
+std::string
+to_string(et v);
+
+// ELF header (ELF32 figure 1-3, ELF64 figure 2)
+template<typename E = Elf64, byte_order Order = byte_order::native>
+struct Ehdr
+{
+        typedef E types;
+        static const byte_order order = Order;
+
+        // ELF identification
+        unsigned char ei_magic[4];
+        elfclass ei_class;
+        elfdata ei_data;
+        unsigned char ei_version;
+        elfosabi ei_osabi;
+        unsigned char ei_abiversion;
+        unsigned char ei_pad[7];
+
+        et               type;           // Object file type
+        typename E::Half machine;        // Machine type
+        typename E::Word version;        // Object file version
+        typename E::Addr entry;          // Entry point address
+        typename E::Off  phoff;          // Program header offset
+        typename E::Off  shoff;          // Section header offset
+        typename E::Word flags;          // Processor-specific flags
+        typename E::Half ehsize;         // ELF header size
+        typename E::Half phentsize;      // Size of program header entry
+        typename E::Half phnum;          // Number of program header entries
+        typename E::Half shentsize;      // Size of section header entry
+        typename E::Half shnum;          // Number of section header entries
+        typename E::Half shstrndx;       // Section name string table index
+
+        template<typename E2>
+        void from(const E2 &o)
+        {
+                std::memcpy(ei_magic, o.ei_magic, sizeof(ei_magic));
+                ei_class = swizzle(o.ei_class, o.order, order);
+                ei_data = swizzle(o.ei_data, o.order, order);
+                ei_version = swizzle(o.ei_version, o.order, order);
+                ei_osabi = swizzle(o.ei_osabi, o.order, order);
+                ei_abiversion = swizzle(o.ei_abiversion, o.order, order);
+                std::memcpy(ei_pad, o.ei_pad, sizeof(ei_pad));
+
+                type      = swizzle(o.type, o.order, order);
+                machine   = swizzle(o.machine, o.order, order);
+                version   = swizzle(o.version, o.order, order);
+                entry     = swizzle(o.entry, o.order, order);
+                phoff     = swizzle(o.phoff, o.order, order);
+                shoff     = swizzle(o.shoff, o.order, order);
+                flags     = swizzle(o.flags, o.order, order);
+                ehsize    = swizzle(o.ehsize, o.order, order);
+                phentsize = swizzle(o.phentsize, o.order, order);
+                phnum     = swizzle(o.phnum, o.order, order);
+                shentsize = swizzle(o.shentsize, o.order, order);
+                shnum     = swizzle(o.shnum, o.order, order);
+                shstrndx  = swizzle(o.shstrndx, o.order, order);
+        }
+};
+
+// Special section indices (ELF32 figure 1-7, ELF64 table 7)
+//
+// This is an integer with a few special values, so this is a regular
+// enum, rather than a type-safe enum.  However, this is declared in a
+// namespace and then used to avoid polluting the elf:: namespace.
+namespace enums {
+enum shn : ElfTypes::Half       // This is a Word in Shdr and Half in Sym.
+{
+        undef = 0,              // Undefined or meaningless
+
+        loproc = 0xff00,        // Processor-specific use
+        hiproc = 0xff1f,
+        loos   = 0xff20,        // Environment-specific use
+        hios   = 0xff3f,
+
+        abs    = 0xfff1,        // Reference is an absolute value
+        common = 0xfff2,        // Symbol declared as a common block
+};
+
+std::string
+to_string(shn v);
+}
+
+using enums::shn;
+
+// Section types (ELF64 table 8)
+enum class sht : ElfTypes::Word
+{
+        null     = 0,           // Marks an unseen section header
+        progbits = 1,           // Contains information defined by the program
+        symtab   = 2,           // Contains a linker symbol table
+        strtab   = 3,           // Contains a string table
+        rela     = 4,           // Contains "Rela" type relocation entries
+        hash     = 5,           // Contains a symbol hash table
+        dynamic  = 6,           // Contains dynamic linking tables
+        note     = 7,           // Contains note information
+        nobits   = 8,           // Contains uninitialized space;
+                                // does not occupy any space in the file
+        rel      = 9,           // Contains "Rel" type relocation entries
+        shlib    = 10,          // Reserved
+        dynsym   = 11,          // Contains a dynamic loader symbol table
+        loos     = 0x60000000,  // Environment-specific use
+        hios     = 0x6FFFFFFF,
+        loproc   = 0x70000000,  // Processor-specific use
+        hiproc   = 0x7FFFFFFF,
+};
+
+std::string
+to_string(sht v);
+
+// Section attributes (ELF64 table 9).  Note: This is an Elf32_Word in
+// ELF32.  We use the larger ELF64 type for the canonical
+// representation and switch it out for a plain Elf32_Word in the
+// ELF32 format.
+enum class shf : Elf64::Xword
+{
+        write     = 0x1,        // Section contains writable data
+        alloc     = 0x2,        // Section is allocated in memory image of program
+        execinstr = 0x4,        // Section contains executable instructions
+        maskos    = 0x0F000000, // Environment-specific use
+        maskproc  = 0xF0000000, // Processor-specific use
+};
+
+std::string
+to_string(shf v);
+
+static inline constexpr shf operator&(shf a, shf b)
+{
+        return (shf)((std::uint64_t)a & (std::uint64_t)b);
+}
+
+static inline constexpr shf operator|(shf a, shf b)
+{
+        return (shf)((std::uint64_t)a | (std::uint64_t)b);
+}
+
+static inline constexpr shf operator^(shf a, shf b)
+{
+        return (shf)((std::uint64_t)a ^ (std::uint64_t)b);
+}
+
+static inline constexpr shf operator~(shf a)
+{
+        return (shf)~((std::uint64_t)a);
+}
+
+static inline shf& operator&=(shf &a, shf b)
+{
+        a = a & b;
+        return a;
+}
+
+static inline shf& operator|=(shf &a, shf b)
+{
+        a = a | b;
+        return a;
+}
+
+static inline shf& operator^=(shf &a, shf b)
+{
+        a = a ^ b;
+        return a;
+}
+
+// Section header (ELF32 figure 1-8, ELF64 figure 3)
+template<typename E = Elf64, byte_order Order = byte_order::native>
+struct Shdr
+{
+        typedef E types;
+        static const byte_order order = Order;
+        // Section numbers are half-words in some structures and full
+        // words in others. Here we declare a local shn type that is
+        // elf::shn for the native byte order, but the full word for
+        // specific encoding byte orders.
+        typedef typename internal::OrderPick<Order, elf::shn, typename E::Word, typename E::Word>::T shn;
+
+        typename E::Word           name; // Section name
+        sht                        type; // Section type
+        typename E::template pick<typename E::Word, shf>::t flags; // Section attributes
+        typename E::Addr           addr; // Virtual address in memory
+        typename E::Off            offset; // Offset in file
+        typename E::Word32_Xword64 size; // Size of section
+        shn                        link; // Link to other section
+        typename E::Word           info; // Miscellaneous information
+        typename E::Word32_Xword64 addralign; // Address alignment boundary
+        typename E::Word32_Xword64 entsize; // Size of entries, if section has table
+
+        template<typename E2>
+        void from(const E2 &o)
+        {
+                name      = swizzle(o.name, o.order, order);
+                type      = swizzle(o.type, o.order, order);
+                flags     = (decltype(flags))swizzle(o.flags, o.order, order);
+                addr      = swizzle(o.addr, o.order, order);
+                offset    = swizzle(o.offset, o.order, order);
+                size      = swizzle(o.size, o.order, order);
+                link      = (decltype(link))swizzle((typename E::Word)o.link, o.order, order);
+                info      = swizzle(o.info, o.order, order);
+                addralign = swizzle(o.addralign, o.order, order);
+                entsize   = swizzle(o.entsize, o.order, order);
+        }
+};
+
+// Segment types (ELF64 table 16)
+enum class pt : ElfTypes::Word
+{
+        null    = 0,            // Unused entry
+        load    = 1,            // Loadable segment
+        dynamic = 2,            // Dynamic linking tables
+        interp  = 3,            // Program interpreter path name
+        note    = 4,            // Note sections
+        shlib   = 5,            // Reserved
+        phdr    = 6,            // Program header table
+        loos    = 0x60000000,   // Environment-specific use
+        hios    = 0x6FFFFFFF,
+        loproc  = 0x70000000,   // Processor-specific use
+        hiproc  = 0x7FFFFFFF,
+};
+
+std::string
+to_string(pt v);
+
+// Segment attributes
+enum class pf : ElfTypes::Word
+{
+        x        = 0x1,         // Execute permission
+        w        = 0x2,         // Write permission
+        r        = 0x4,         // Read permission
+        maskos   = 0x00FF0000,  // Environment-specific use
+        maskproc = 0xFF000000,  // Processor-specific use
+};
+
+std::string
+to_string(pf v);
+
+static inline constexpr pf operator&(pf a, pf b)
+{
+        return (pf)((std::uint64_t)a & (std::uint64_t)b);
+}
+
+static inline constexpr pf operator|(pf a, pf b)
+{
+        return (pf)((std::uint64_t)a | (std::uint64_t)b);
+}
+
+static inline constexpr pf operator^(pf a, pf b)
+{
+        return (pf)((std::uint64_t)a ^ (std::uint64_t)b);
+}
+
+static inline constexpr pf operator~(pf a)
+{
+        return (pf)~((std::uint64_t)a);
+}
+
+static inline pf& operator&=(pf &a, pf b)
+{
+        a = a & b;
+        return a;
+}
+
+static inline pf& operator|=(pf &a, pf b)
+{
+        a = a | b;
+        return a;
+}
+
+static inline pf& operator^=(pf &a, pf b)
+{
+        a = a ^ b;
+        return a;
+}
+
+// Program header (ELF32 figure 2-1, ELF64 figure 6)
+template<typename E = Elf64, byte_order Order = byte_order::native>
+struct Phdr;
+
+template<byte_order Order>
+struct Phdr<Elf32, Order>
+{
+        typedef Elf32 types;
+        static const byte_order order = Order;
+
+        pt           type;      // Type of segment
+        Elf32::Off   offset;    // Offset in file
+        Elf32::Addr  vaddr;     // Virtual address in memory
+        Elf32::Addr  paddr;     // Reserved
+        Elf32::Word  filesz;    // Size of segment in file
+        Elf32::Word  memsz;     // Size of segment in memory
+        pf           flags;     // Segment attributes
+        Elf32::Word  align;     // Alignment of segment
+
+        template<typename E2>
+        void from(const E2 &o)
+        {
+                type   = swizzle(o.type, o.order, order);
+                offset = swizzle(o.offset, o.order, order);
+                vaddr  = swizzle(o.vaddr, o.order, order);
+                paddr  = swizzle(o.paddr, o.order, order);
+                filesz = swizzle(o.filesz, o.order, order);
+                memsz  = swizzle(o.memsz, o.order, order);
+                flags  = swizzle(o.flags, o.order, order);
+                align  = swizzle(o.align, o.order, order);
+        }
+};
+
+template<byte_order Order>
+struct Phdr<Elf64, Order>
+{
+        typedef Elf64 types;
+        static const byte_order order = Order;
+
+        pt           type;      // Type of segment
+        pf           flags;     // Segment attributes
+        Elf64::Off   offset;    // Offset in file
+        Elf64::Addr  vaddr;     // Virtual address in memory
+        Elf64::Addr  paddr;     // Reserved
+        Elf64::Xword filesz;    // Size of segment in file
+        Elf64::Xword memsz;     // Size of segment in memory
+        Elf64::Xword align;     // Alignment of segment
+
+        template<typename E2>
+        void from(const E2 &o)
+        {
+                type   = swizzle(o.type, o.order, order);
+                offset = swizzle(o.offset, o.order, order);
+                vaddr  = swizzle(o.vaddr, o.order, order);
+                paddr  = swizzle(o.paddr, o.order, order);
+                filesz = swizzle(o.filesz, o.order, order);
+                memsz  = swizzle(o.memsz, o.order, order);
+                flags  = swizzle(o.flags, o.order, order);
+                align  = swizzle(o.align, o.order, order);
+        }
+};
+
+// Symbol bindings (ELF32 figure 1-16, ELF64 table 14)
+enum class stb : unsigned char
+{
+        local  = 0,             // Not visible outside the object file
+        global = 1,             // Global symbol
+        weak   = 2,             // Global scope, but with lower
+                                // precedence than global symbols
+        loos   = 10,            // Environment-specific use
+        hios   = 12,
+        loproc = 13,            // Processor-specific use
+        hiproc = 15,
+};
+
+std::string
+to_string(stb v);
+
+// Symbol types (ELF32 figure 1-17, ELF64 table 15)
+enum class stt : unsigned char
+{
+        notype  = 0,            // No type (e.g., absolute symbol)
+        object  = 1,            // Data object
+        func    = 2,            // Function entry point
+        section = 3,            // Symbol is associated with a section
+        file    = 4,            // Source file associated with the
+                                // object file
+        loos    = 10,           // Environment-specific use
+        hios    = 12,
+        loproc  = 13,           // Processor-specific use
+        hiproc  = 15,
+};
+
+std::string
+to_string(stt v);
+
+// Symbol table (ELF32 figure 1-15, ELF64 figure 4)
+template<typename E = Elf64, byte_order Order = byte_order::native>
+struct Sym;
+
+template<byte_order Order>
+struct Sym<Elf32, Order>
+{
+        typedef Elf32 types;
+        static const byte_order order = Order;
+
+        Elf32::Word   name;  // Symbol name (strtab offset)
+        Elf32::Addr   value; // Symbol value (address)
+        Elf32::Word   size;  // Size of object
+        unsigned char info;  // Type and binding attributes
+        unsigned char other; // Reserved
+        shn           shnxd; // Section table index
+
+        template<typename E2>
+        void from(const E2 &o)
+        {
+                name  = swizzle(o.name, o.order, order);
+                value = swizzle(o.value, o.order, order);
+                size  = swizzle(o.size, o.order, order);
+                info  = o.info;
+                other = o.other;
+                shnxd = swizzle(o.shnxd, o.order, order);
+        }
+
+        stb binding() const
+        {
+                return (stb)(info >> 4);
+        }
+
+        void set_binding(stb v)
+        {
+                info = (info & 0x0F) | ((unsigned char)v << 4);
+        }
+
+        stt type() const
+        {
+                return (stt)(info & 0xF);
+        }
+
+        void set_type(stt v)
+        {
+                info = (info & 0xF0) | (unsigned char)v;
+        }
+};
+
+template<byte_order Order>
+struct Sym<Elf64, Order>
+{
+        typedef Elf64 types;
+        static const byte_order order = Order;
+
+        Elf64::Word   name;  // Symbol name (strtab offset)
+        unsigned char info;  // Type and binding attributes
+        unsigned char other; // Reserved
+        shn           shnxd; // Section table index
+        Elf64::Addr   value; // Symbol value (address)
+        Elf64::Xword  size;  // Size of object
+
+        template<typename E2>
+        void from(const E2 &o)
+        {
+                name  = swizzle(o.name, o.order, order);
+                value = swizzle(o.value, o.order, order);
+                size  = swizzle(o.size, o.order, order);
+                info  = o.info;
+                other = o.other;
+                shnxd = swizzle(o.shnxd, o.order, order);
+        }
+
+        stb binding() const
+        {
+                return (stb)(info >> 4);
+        }
+
+        void set_binding(stb v)
+        {
+                info = (info & 0xF) | ((unsigned char)v << 4);
+        }
+
+        stt type() const
+        {
+                return (stt)(info & 0xF);
+        }
+
+        void set_type(stt v)
+        {
+                info = (info & 0xF0) | (unsigned char)v;
+        }
+};
+
+ELFPP_END_NAMESPACE
+
+#endif

3party/libelfin/elf/elf++.hh

@@ -0,0 +1,454 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#ifndef _ELFPP_HH_
+#define _ELFPP_HH_
+
+#include "common.hh"
+#include "data.hh"
+
+#include <cstddef>
+#include <memory>
+#include <stdexcept>
+#include <vector>
+
+ELFPP_BEGIN_NAMESPACE
+
+class elf;
+class loader;
+class section;
+class strtab;
+class symtab;
+class segment;
+// XXX Audit for binary compatibility
+
+// XXX Segments, other section types
+
+/**
+ * An exception indicating malformed ELF data.
+ */
+class format_error : public std::runtime_error
+{
+public:
+        explicit format_error(const std::string &what_arg)
+                : std::runtime_error(what_arg) { }
+        explicit format_error(const char *what_arg)
+                : std::runtime_error(what_arg) { }
+};
+
+/**
+ * An ELF file.
+ *
+ * This class is internally reference counted and efficiently
+ * copyable.
+ *
+ * Raw pointers to ELF data returned by any method of this object or
+ * any object derived from this object point directly into loaded
+ * section data.  Hence, callers must ensure that the loader passed to
+ * this file remains live as long as any such pointer is in use.
+ * Keeping any object that can return such a pointer live is
+ * sufficient to keep the loader live.
+ */
+class elf
+{
+public:
+        /**
+         * Construct an ELF file that is backed by data read from the
+         * given loader.
+         */
+        explicit elf(const std::shared_ptr<loader> &l);
+
+        /**
+         * Construct an ELF file that is initially not valid.  Calling
+         * methods other than operator= and valid on this results in
+         * undefined behavior.
+         */
+        elf() = default;
+        elf(const elf &o) = default;
+        elf(elf &&o) = default;
+
+        elf& operator=(const elf &o) = default;
+
+        bool valid() const
+        {
+                return !!m;
+        }
+
+        /**
+         * Return the ELF file header in canonical form (ELF64 in
+         * native byte order).
+         */
+        const Ehdr<> &get_hdr() const;
+
+        /**
+         * Return the loader used by this file.
+         */
+        std::shared_ptr<loader> get_loader() const;
+
+        /**
+         * Return the segments in this file.
+         */
+        const std::vector<segment> &segments() const;
+
+        /**
+         * Return the segment at the given index. If no such segment
+         * is found, return an invalid segment.
+         */
+        const segment &get_segment(unsigned index) const;
+
+        /**
+         * Return the sections in this file.
+         */
+        const std::vector<section> &sections() const;
+
+        /**
+         * Return the section with the specified name. If no such
+         * section is found, return an invalid section.
+         */
+        const section &get_section(const std::string &name) const;
+
+        /**
+         * Return the section at the given index.  If no such section
+         * is found, return an invalid section.
+         */
+        const section &get_section(unsigned index) const;
+
+private:
+        struct impl;
+        std::shared_ptr<impl> m;
+};
+
+/**
+ * An interface for loading sections of an ELF file.
+ */
+class loader
+{
+public:
+        virtual ~loader() { }
+
+        /**
+         * Load the requested file section into memory and return a
+         * pointer to the beginning of it.  This memory must remain
+         * valid and unchanged until the loader is destroyed.  If the
+         * loader cannot satisfy the full request for any reason
+         * (including a premature EOF), it must throw an exception.
+         */
+        virtual const void *load(off_t offset, size_t size) = 0;
+};
+
+/**
+ * An mmap-based loader that maps requested sections on demand.  This
+ * will close fd when done, so the caller should dup the file
+ * descriptor if it intends to continue using it.
+ */
+std::shared_ptr<loader> create_mmap_loader(int fd);
+
+/**
+ * An exception indicating that a section is not of the requested type.
+ */
+class section_type_mismatch : public std::logic_error
+{
+public:
+        explicit section_type_mismatch(const std::string &what_arg)
+                : std::logic_error(what_arg) { }
+        explicit section_type_mismatch(const char *what_arg)
+                : std::logic_error(what_arg) { }
+};
+
+/**
+ * An ELF segment.
+ *
+ * This class is internally reference counted and efficiently
+ * copyable.
+ */
+class segment
+{
+public:
+       /**
+        * Construct a segment that is initially not valid.  Calling
+        * methods other than operator= and valid on this results in
+        * undefined behavior.
+        */
+       segment() { }
+
+       segment(const elf &f, const void *hdr);
+       segment(const segment &o) = default;
+       segment(segment &&o) = default;
+
+       /**
+        * Return true if this segment is valid and corresponds to a
+        * segment in the ELF file.
+        */
+       bool valid() const
+       {
+               return !!m;
+       }
+
+       /**
+        * Return the ELF section header in canonical form (ELF64 in
+        * native byte order).
+        */
+       const Phdr<> &get_hdr() const;
+
+       /**
+        * Return this segment's data. The returned buffer will
+        * be file_size() bytes long.
+        */
+       const void *data() const;
+
+       /**
+        * Return the on disk size of this segment in bytes.
+        */
+       size_t file_size() const;
+
+       /**
+        * Return the in-memory size of this segment in bytes.
+        * Bytes between file_size() and mem_size() are implicitly zeroes.
+        */
+       size_t mem_size() const;
+
+private:
+       struct impl;
+       std::shared_ptr<impl> m;
+};
+
+/**
+ * An ELF section.
+ *
+ * This class is internally reference counted and efficiently
+ * copyable.
+ */
+class section
+{
+public:
+        /**
+         * Construct a section that is initially not valid.  Calling
+         * methods other than operator= and valid on this results in
+         * undefined behavior.
+         */
+        section() { }
+
+        section(const elf &f, const void *hdr);
+        section(const section &o) = default;
+        section(section &&o) = default;
+
+        /**
+         * Return true if this section is valid and corresponds to a
+         * section in the ELF file.
+         */
+        bool valid() const
+        {
+                return !!m;
+        }
+
+        /**
+         * Return the ELF section header in canonical form (ELF64 in
+         * native byte order).
+         */
+        const Shdr<> &get_hdr() const;
+
+        /**
+         * Return this section's name.
+         */
+        const char *get_name(size_t *len_out) const;
+        /**
+         * Return this section's name.  The returned string copies its
+         * data, so loader liveness requirements don't apply.
+         */
+        std::string get_name() const;
+
+        /**
+         * Return this section's data.  If this is a NOBITS section,
+         * return nullptr.
+         */
+        const void *data() const;
+        /**
+         * Return the size of this section in bytes.
+         */
+        size_t size() const;
+
+        /**
+         * Return this section as a strtab.  Throws
+         * section_type_mismatch if this section is not a string
+         * table.
+         */
+        strtab as_strtab() const;
+
+        /**
+         * Return this section as a symtab.  Throws
+         * section_type_mismatch if this section is not a symbol
+         * table.
+         */
+        symtab as_symtab() const;
+
+private:
+        struct impl;
+        std::shared_ptr<impl> m;
+};
+
+/**
+ * A string table.
+ *
+ * This class is internally reference counted and efficiently
+ * copyable.
+ */
+class strtab
+{
+public:
+        /**
+         * Construct a strtab that is initially not valid.  Calling
+         * methods other than operator= and valid on this results in
+         * undefined behavior.
+         */
+        strtab() = default;
+        strtab(elf f, const void *data, size_t size);
+
+        bool valid() const
+        {
+                return !!m;
+        }
+
+        /**
+         * Return the string at the given offset in this string table.
+         * If the offset is out of bounds, throws std::range_error.
+         * This is very efficient since the returned pointer points
+         * directly into the loaded section, though this still
+         * verifies that the returned string is NUL-terminated.
+         */
+        const char *get(Elf64::Off offset, size_t *len_out) const;
+        /**
+         * Return the string at the given offset in this string table.
+         */
+        std::string get(Elf64::Off offset) const;
+
+private:
+        struct impl;
+        std::shared_ptr<impl> m;
+};
+
+/**
+ * A symbol from a symbol table.
+ */
+class sym
+{
+        const strtab strs;
+        Sym<> data;
+
+public:
+        sym(elf f, const void *data, strtab strs);
+
+        /**
+         * Return this symbol's raw data.
+         */
+        const Sym<> &get_data() const
+        {
+                return data;
+        }
+
+        /**
+         * Return this symbol's name.
+         *
+         * This returns a pointer into the string table and, as such,
+         * is very efficient.  If len_out is non-nullptr, *len_out
+         * will be set the length of the returned string.
+         */
+        const char *get_name(size_t *len_out) const;
+
+        /**
+         * Return this symbol's name as a string.
+         */
+        std::string get_name() const;
+};
+
+/**
+ * A symbol table.
+ *
+ * This class is internally reference counted and efficiently
+ * copyable.
+ */
+class symtab
+{
+public:
+        /**
+         * Construct a symtab that is initially not valid.  Calling
+         * methods other than operator= and valid on this results in
+         * undefined behavior.
+         */
+        symtab() = default;
+        symtab(elf f, const void *data, size_t size, strtab strs);
+
+        bool valid() const
+        {
+                return !!m;
+        }
+
+        class iterator
+        {
+                const elf f;
+                const strtab strs;
+                const char *pos;
+                size_t stride;
+
+                iterator(const symtab &tab, const char *pos);
+                friend class symtab;
+
+        public:
+                sym operator*() const
+                {
+                        return sym(f, pos, strs);
+                }
+
+                iterator& operator++()
+                {
+                        return *this += 1;
+                }
+
+                iterator operator++(int)
+                {
+                        iterator cur(*this);
+                        *this += 1;
+                        return cur;
+                }
+
+                iterator& operator+=(std::ptrdiff_t x)
+                {
+                        pos += x * stride;
+                        return *this;
+                }
+
+                iterator& operator-=(std::ptrdiff_t x)
+                {
+                        pos -= x * stride;
+                        return *this;
+                }
+
+                bool operator==(iterator &o) const
+                {
+                        return pos == o.pos;
+                }
+
+                bool operator!=(iterator &o) const
+                {
+                        return pos != o.pos;
+                }
+        };
+
+        /**
+         * Return an iterator to the first symbol.
+         */
+        iterator begin() const;
+
+        /**
+         * Return an iterator just past the last symbol.
+         */
+        iterator end() const;
+
+private:
+        struct impl;
+        std::shared_ptr<impl> m;
+};
+
+ELFPP_END_NAMESPACE
+
+#endif

3party/libelfin/elf/elf.cc

@@ -0,0 +1,403 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "elf++.hh"
+
+#include <cstring>
+
+using namespace std;
+
+ELFPP_BEGIN_NAMESPACE
+
+template<template<typename E, byte_order Order> class Hdr>
+void canon_hdr(Hdr<Elf64, byte_order::native> *out, const void *data,
+               elfclass ei_class, elfdata ei_data)
+{
+        switch (ei_class) {
+        case elfclass::_32:
+                switch (ei_data) {
+                case elfdata::lsb:
+                        out->from(*(Hdr<Elf32, byte_order::lsb>*)data);
+                        break;
+                case elfdata::msb:
+                        out->from(*(Hdr<Elf32, byte_order::msb>*)data);
+                        break;
+                }
+                break;
+        case elfclass::_64:
+                switch (ei_data) {
+                case elfdata::lsb:
+                        out->from(*(Hdr<Elf64, byte_order::lsb>*)data);
+                        break;
+                case elfdata::msb:
+                        out->from(*(Hdr<Elf64, byte_order::msb>*)data);
+                        return;
+                }
+        }
+}
+
+//////////////////////////////////////////////////////////////////
+// class elf
+//
+
+struct elf::impl
+{
+        impl(const shared_ptr<loader> &l)
+                : l(l) { }
+
+        const shared_ptr<loader> l;
+        Ehdr<> hdr;
+        vector<section> sections;
+        vector<segment> segments;
+
+        section invalid_section;
+        segment invalid_segment;
+};
+
+elf::elf(const std::shared_ptr<loader> &l)
+        : m(make_shared<impl>(l))
+{
+        // Read the first six bytes to check the magic number, ELF
+        // class, and byte order.
+        struct core_hdr
+        {
+                char ei_magic[4];
+                elfclass ei_class;
+                elfdata ei_data;
+                unsigned char ei_version;
+        } *core_hdr = (struct core_hdr*)l->load(0, sizeof *core_hdr);
+
+        // Check basic header
+        if (strncmp(core_hdr->ei_magic, "\x7f" "ELF", 4) != 0)
+                throw format_error("bad ELF magic number");
+        if (core_hdr->ei_version != 1)
+                throw format_error("unknown ELF version");
+        if (core_hdr->ei_class != elfclass::_32 &&
+            core_hdr->ei_class != elfclass::_64)
+                throw format_error("bad ELF class");
+        if (core_hdr->ei_data != elfdata::lsb &&
+            core_hdr->ei_data != elfdata::msb)
+                throw format_error("bad ELF data order");
+
+        // Read in the real header and canonicalize it
+        size_t hdr_size = (core_hdr->ei_class == elfclass::_32 ?
+                           sizeof(Ehdr<Elf32>) : sizeof(Ehdr<Elf64>));
+        const void *hdr = l->load(0, hdr_size);
+        canon_hdr(&m->hdr, hdr, core_hdr->ei_class, core_hdr->ei_data);
+
+        // More checks
+        if (m->hdr.version != 1)
+                throw format_error("bad section ELF version");
+        if (m->hdr.shnum && m->hdr.shstrndx >= m->hdr.shnum)
+                throw format_error("bad section name string table index");
+
+        // Load segments
+        const void *seg_data = l->load(m->hdr.phoff,
+                                       m->hdr.phentsize * m->hdr.phnum);
+        for (unsigned i = 0; i < m->hdr.phnum; i++) {
+                const void *seg = ((const char*)seg_data) + i * m->hdr.phentsize;
+                m->segments.push_back(segment(*this, seg));
+        }
+
+        // Load sections
+        const void *sec_data = l->load(m->hdr.shoff,
+                                       m->hdr.shentsize * m->hdr.shnum);
+        for (unsigned i = 0; i < m->hdr.shnum; i++) {
+                const void *sec = ((const char*)sec_data) + i * m->hdr.shentsize;
+                // XXX Circular reference.  Maybe this should be
+                // constructed on the fly?  Canonicalizing the header
+                // isn't super-cheap.
+                m->sections.push_back(section(*this, sec));
+        }
+}
+
+const Ehdr<> &
+elf::get_hdr() const
+{
+        return m->hdr;
+}
+
+shared_ptr<loader>
+elf::get_loader() const
+{
+        return m->l;
+}
+
+const std::vector<section> &
+elf::sections() const
+{
+        return m->sections;
+}
+
+const std::vector<segment> &
+elf::segments() const
+{
+        return m->segments;
+}
+
+const section &
+elf::get_section(const std::string &name) const
+{
+        for (auto &sec : sections())
+                if (name == sec.get_name(nullptr))
+                        return sec;
+        return m->invalid_section;
+}
+
+const section &
+elf::get_section(unsigned index) const
+{
+        if (index >= sections().size())
+                return m->invalid_section;
+        return sections().at(index);
+}
+
+const segment&
+elf::get_segment(unsigned index) const
+{
+        if (index >= segments().size())
+                return m->invalid_segment;
+        return segments().at(index);
+}
+
+//////////////////////////////////////////////////////////////////
+// class segment
+//
+
+struct segment::impl {
+        impl(const elf &f)
+                : f(f), data(nullptr) { }
+
+        const elf f;
+        Phdr<> hdr;
+        const void *data;
+};
+
+segment::segment(const elf &f, const void *hdr)
+    : m(make_shared<impl>(f)) {
+        canon_hdr(&m->hdr, hdr, f.get_hdr().ei_class, f.get_hdr().ei_data);
+}
+
+const Phdr<> &
+segment::get_hdr() const {
+        return m->hdr;
+}
+
+const void *
+segment::data() const {
+        if (!m->data)
+                m->data = m->f.get_loader()->load(m->hdr.offset,
+                                                  m->hdr.filesz);
+        return m->data;
+}
+
+size_t
+segment::file_size() const {
+        return m->hdr.filesz;
+}
+
+size_t
+segment::mem_size() const {
+        return m->hdr.memsz;
+}
+
+//////////////////////////////////////////////////////////////////
+// class section
+//
+
+std::string
+enums::to_string(shn v)
+{
+        if (v == shn::undef)
+                return "undef";
+        if (v == shn::abs)
+                return "abs";
+        if (v == shn::common)
+                return "common";
+        return std::to_string(v);
+}
+
+struct section::impl
+{
+        impl(const elf &f)
+                : f(f), name(nullptr), data(nullptr) { }
+
+        const elf f;
+        Shdr<> hdr;
+        const char *name;
+        size_t name_len;
+        const void *data;
+};
+
+section::section(const elf &f, const void *hdr)
+        : m(make_shared<impl>(f))
+{
+        canon_hdr(&m->hdr, hdr, f.get_hdr().ei_class, f.get_hdr().ei_data);
+}
+
+const Shdr<> &
+section::get_hdr() const
+{
+        return m->hdr;
+}
+
+const char *
+section::get_name(size_t *len_out) const
+{
+        // XXX Should the section name strtab be cached?
+        if (!m->name)
+                m->name = m->f.get_section(m->f.get_hdr().shstrndx)
+                        .as_strtab().get(m->hdr.name, &m->name_len);
+        if (len_out)
+                *len_out = m->name_len;
+        return m->name;
+}
+
+string
+section::get_name() const
+{
+        return get_name(nullptr);
+}
+
+const void *
+section::data() const
+{
+        if (m->hdr.type == sht::nobits)
+                return nullptr;
+        if (!m->data)
+                m->data = m->f.get_loader()->load(m->hdr.offset, m->hdr.size);
+        return m->data;
+}
+
+size_t
+section::size() const
+{
+        return m->hdr.size;
+}
+
+strtab
+section::as_strtab() const
+{
+        if (m->hdr.type != sht::strtab)
+                throw section_type_mismatch("cannot use section as strtab");
+        return strtab(m->f, data(), size());
+}
+
+symtab
+section::as_symtab() const
+{
+        if (m->hdr.type != sht::symtab && m->hdr.type != sht::dynsym)
+                throw section_type_mismatch("cannot use section as symtab");
+        return symtab(m->f, data(), size(),
+                      m->f.get_section(get_hdr().link).as_strtab());
+}
+
+//////////////////////////////////////////////////////////////////
+// class strtab
+//
+
+struct strtab::impl
+{
+        impl(const elf &f, const char *data, const char *end)
+                : f(f), data(data), end(end) { }
+
+        const elf f;
+        const char *data, *end;
+};
+
+strtab::strtab(elf f, const void *data, size_t size)
+        : m(make_shared<impl>(f, (const char*)data, (const char *)data + size))
+{
+}
+
+const char *
+strtab::get(Elf64::Off offset, size_t *len_out) const
+{
+        const char *start = m->data + offset;
+
+        if (start >= m->end)
+                throw range_error("string offset " + std::to_string(offset) + " exceeds section size");
+
+        // Find the null terminator
+        const char *p = start;
+        while (p < m->end && *p)
+                p++;
+        if (p == m->end)
+                throw format_error("unterminated string");
+
+        if (len_out)
+                *len_out = p - start;
+        return start;
+}
+
+std::string
+strtab::get(Elf64::Off offset) const
+{
+        return get(offset, nullptr);
+}
+
+//////////////////////////////////////////////////////////////////
+// class sym
+//
+
+sym::sym(elf f, const void *data, strtab strs)
+        : strs(strs)
+{
+        canon_hdr(&this->data, data, f.get_hdr().ei_class, f.get_hdr().ei_data);
+}
+
+const char *
+sym::get_name(size_t *len_out) const
+{
+        return strs.get(get_data().name, len_out);
+}
+
+std::string
+sym::get_name() const
+{
+        return strs.get(get_data().name);
+}
+
+//////////////////////////////////////////////////////////////////
+// class symtab
+//
+
+struct symtab::impl
+{
+        impl(const elf &f, const char *data, const char *end, strtab strs)
+                : f(f), data(data), end(end), strs(strs) { }
+
+        const elf f;
+        const char *data, *end;
+        const strtab strs;
+};
+
+symtab::symtab(elf f, const void *data, size_t size, strtab strs)
+        : m(make_shared<impl>(f, (const char*)data, (const char *)data + size,
+                              strs))
+{
+}
+
+symtab::iterator::iterator(const symtab &tab, const char *pos)
+        : f(tab.m->f), strs(tab.m->strs), pos(pos)
+{
+        if (f.get_hdr().ei_class == elfclass::_32)
+                stride = sizeof(Sym<Elf32>);
+        else
+                stride = sizeof(Sym<Elf64>);
+}
+
+symtab::iterator
+symtab::begin() const
+{
+        return iterator(*this, m->data);
+}
+
+symtab::iterator
+symtab::end() const
+{
+        return iterator(*this, m->end);
+}
+
+ELFPP_END_NAMESPACE

3party/libelfin/elf/enum-print.py

@@ -0,0 +1,163 @@
+# Copyright (c) 2013 Austin T. Clements. All rights reserved.
+# Use of this source code is governed by an MIT license
+# that can be found in the LICENSE file.
+
+import sys, re
+from optparse import OptionParser
+
+def read_toks():
+    data = sys.stdin.read()
+    while data:
+        data = data.lstrip()
+        if data.startswith("//") or data.startswith("#"):
+            data = data.split("\n",1)[1]
+        elif data.startswith("/*"):
+            data = data.split("*/",1)[1]
+        elif data.startswith("\"") or data.startswith("'"):
+            c = data[0]
+            m = re.match(r'%s([^\\%s]|\\.)*%s' % (c,c,c), data)
+            yield m.group(0)
+            data = data[m.end():]
+        else:
+            m = re.match(r"[_a-zA-Z0-9]+|[{}();]|[^_a-zA-Z0-9 \n\t\f]+", data)
+            yield m.group(0)
+            data = data[m.end():]
+
+enums = {}
+
+def do_top_level(toks, ns=[]):
+    while toks:
+        tok = toks.pop(0)
+        if tok == "enum" and toks[0] == "class":
+            toks.pop(0)
+            name = toks.pop(0)
+            # Get to the first token in the body
+            while toks.pop(0) != "{":
+                pass
+            # Consume body and close brace
+            do_enum_body("::".join(ns + [name]), toks)
+        elif tok == "class":
+            name = do_qname(toks)
+            # Find the class body, if there is one
+            while toks[0] != "{" and toks[0] != ";":
+                toks.pop(0)
+            # Enter the class's namespace
+            if toks[0] == "{":
+                toks.pop(0)
+                do_top_level(toks, ns + [name])
+        elif tok == "{":
+            # Enter an unknown namespace
+            do_top_level(toks, ns + [None])
+        elif tok == "}":
+            # Exit the namespace
+            assert len(ns)
+            return
+        elif not ns and tok == "string" and toks[:2] == ["to_string", "("]:
+            # Get the argument type and name
+            toks.pop(0)
+            toks.pop(0)
+            typ = do_qname(toks)
+            if typ not in enums:
+                continue
+            arg = toks.pop(0)
+            assert toks[0] == ")"
+
+            if typ in options.mask:
+                make_to_string_mask(typ, arg)
+            else:
+                make_to_string(typ, arg)
+
+def fmt_value(typ, key):
+    if options.no_type:
+        val = key
+    else:
+        val = "%s%s%s" % (typ, options.separator, key)
+    if options.strip_underscore:
+        val = val.strip("_")
+    return val
+
+def expr_remainder(typ, arg):
+    if options.hex:
+        return "\"(%s)0x\" + to_hex((int)%s)" % (typ, arg)
+    else:
+        return "\"(%s)\" + std::to_string((int)%s)" % (typ, arg)
+
+def make_to_string(typ, arg):
+    print("std::string")
+    print("to_string(%s %s)" % (typ, arg))
+    print("{")
+    print("        switch (%s) {" % arg)
+    for key in enums[typ]:
+        if key in options.exclude:
+            print("        case %s::%s: break;" % (typ, key))
+            continue
+        print("        case %s::%s: return \"%s\";" % \
+            (typ, key, fmt_value(typ, key)))
+    print("        }")
+    print("        return %s;" % expr_remainder(typ, arg))
+    print("}")
+    print()
+
+def make_to_string_mask(typ, arg):
+    print("std::string")
+    print("to_string(%s %s)" % (typ, arg))
+    print("{")
+    print("        std::string res;")
+    for key in enums[typ]:
+        if key in options.exclude:
+            continue
+        print("        if ((%s & %s::%s) == %s::%s) { res += \"%s|\"; %s &= ~%s::%s; }" % \
+            (arg, typ, key, typ, key, fmt_value(typ, key), arg, typ, key))
+    print("        if (res.empty() || %s != (%s)0) res += %s;" % \
+        (arg, typ, expr_remainder(typ, arg)))
+    print("        else res.pop_back();")
+    print("        return res;")
+    print("}")
+    print()
+
+def do_enum_body(name, toks):
+    keys = []
+    while True:
+        key = toks.pop(0)
+        if key == "}":
+            assert toks.pop(0) == ";"
+            enums[name] = keys
+            return
+        keys.append(key)
+        if toks[0] == "=":
+            toks.pop(0)
+            toks.pop(0)
+        if toks[0] == ",":
+            toks.pop(0)
+        else:
+            assert toks[0] == "}"
+
+def do_qname(toks):
+    # Get a nested-name-specifier followed by an identifier
+    res = []
+    while True:
+        res.append(toks.pop(0))
+        if toks[0] != "::":
+            return "::".join(res)
+        toks.pop(0)
+
+parser = OptionParser()
+parser.add_option("-x", "--exclude", dest="exclude", action="append",
+                  help="exclude FIELD", metavar="FIELD", default=[])
+parser.add_option("-u", "--strip-underscore", dest="strip_underscore",
+                  action="store_true",
+                  help="strip leading and trailing underscores")
+parser.add_option("-s", "--separator", dest="separator",
+                  help="use SEP between type and field", metavar="SEP",
+                  default="::")
+parser.add_option("--hex", dest="hex", action="store_true",
+                  help="return unknown values in hex", default=False)
+parser.add_option("--no-type", dest="no_type", action="store_true",
+                  help="omit type")
+parser.add_option("--mask", dest="mask", action="append",
+                  help="treat TYPE as a bit-mask", metavar="TYPE", default=[])
+(options, args) = parser.parse_args()
+if args:
+    parser.error("expected 0 arguments")
+
+do_top_level(list(read_toks()))

3party/libelfin/elf/mmap_loader.cc

@@ -0,0 +1,60 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#include "elf++.hh"
+
+#include <system_error>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+using namespace std;
+
+ELFPP_BEGIN_NAMESPACE
+
+class mmap_loader : public loader
+{
+        void *base;
+        size_t lim;
+
+public:
+        mmap_loader(int fd)
+        {
+                off_t end = lseek(fd, 0, SEEK_END);
+                if (end == (off_t)-1)
+                        throw system_error(errno, system_category(),
+                                           "finding file length");
+                lim = end;
+
+                base = mmap(nullptr, lim, PROT_READ, MAP_SHARED, fd, 0);
+                if (base == MAP_FAILED)
+                        throw system_error(errno, system_category(),
+                                           "mmap'ing file");
+                close(fd);
+        }
+
+        ~mmap_loader()
+        {
+                munmap(base, lim);
+        }
+
+        const void *load(off_t offset, size_t size)
+        {
+                if (offset + size > lim)
+                        throw range_error("offset exceeds file size");
+                return (const char*)base + offset;
+        }
+};
+
+std::shared_ptr<loader>
+create_mmap_loader(int fd)
+{
+        return make_shared<mmap_loader>(fd);
+}
+
+ELFPP_END_NAMESPACE

3party/libelfin/elf/to_hex.hh

@@ -0,0 +1,34 @@
+// Copyright (c) 2013 Austin T. Clements. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+#ifndef _ELFPP_TO_HEX_HH_
+#define _ELFPP_TO_HEX_HH_
+
+#include <string>
+#include <type_traits>
+
+template<typename T>
+std::string
+to_hex(T v)
+{
+        static_assert(std::is_integral<T>::value,
+                "to_hex applied to non-integral type");
+        if (v == 0)
+                return std::string("0");
+        char buf[sizeof(T)*2 + 1];
+        char *pos = &buf[sizeof(buf)-1];
+        *pos-- = '\0';
+        while (v && pos >= buf) {
+                int digit = v & 0xf;
+                if (digit < 10)
+                        *pos = '0' + digit;
+                else
+                        *pos = 'a' + (digit - 10);
+                pos--;
+                v >>= 4;
+        }
+        return std::string(pos + 1);
+}
+
+#endif // _ELFPP_TO_HEX_HH_

CMakeLists.txt

@@ -7,6 +7,8 @@ project(
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_STANDARD_EXTENSIONS OFF)
+# set(CMAKE_C_FLAGS "-gdwarf-3 -gstrict-dwarf") set(CMAKE_CXX_FLAGS "-gdwarf-3
+# -gstrict-dwarf")
 
 option(SLED_BUILD_BENCHMARK "Build benchmark" OFF)
 option(SLED_BUILD_TESTS "Build tests" OFF)
@@ -24,6 +26,7 @@ target_include_directories(benchmark_main PUBLIC src/)
 
 add_library(sled STATIC "")
 
+add_subdirectory(3party/libelfin EXCLUDE_FROM_ALL)
 add_subdirectory(3party/minilua EXCLUDE_FROM_ALL)
 # add_subdirectory(3party/gperftools EXCLUDE_FROM_ALL)
 add_subdirectory(3party/asyncplusplus EXCLUDE_FROM_ALL)
@@ -50,8 +53,7 @@ target_include_directories(sled PUBLIC src/ 3party/eigen 3party/inja
                                        3party/rxcpp)
 target_sources(
   sled
-  PRIVATE 
-  src/sled/async/async.cc
+  PRIVATE src/sled/async/async.cc
           src/sled/debugging/demangle.cc
           src/sled/debugging/symbolize.cc
           src/sled/event_bus/event_bus.cc
@@ -88,20 +90,12 @@ target_sources(
           src/sled/time_utils.cc
           src/sled/units/time_delta.cc
           src/sled/units/timestamp.cc
-          src/sled/uri.cc
-)
-# set(BUILD_RTTR_DYNAMIC OFF) set(BUILD_UNIT_TESTS OFF)
-# set(BUILD_WITH_STATIC_RUNTIME_LIBS ON) set(BUILD_WITH_DOCUMENTATION OFF)
-# add_subdirectory(3party/rttr EXCLUDE_FROM_ALL) include(CheckCCompilerFlag)
-# check_c_compiler_flag("-Wl,--whole-archive" SUPPORT_COMPILE_WHOLE_ARCHIVE)
-# if(SUPPORT_COMPILE_WHOLE_ARCHIVE) set(WHOLE_ARCHIVE_WRAPPER_START
-# "-Wl,--whole-archive") set(WHOLE_ARCHIVE_WRAPPER_END "-Wl,--no-whole-archive")
-# endif()
+          src/sled/uri.cc)
 
 target_link_libraries(
   sled
   PUBLIC rpc_core fmt marl Async++ minilua
-  PRIVATE dl
+  PRIVATE dl elf
   # protobuf::libprotobuf ${WHOLE_ARCHIVE_WRAPPER_START}
   # tcmalloc_and_profiler_static ${WHOLE_ARCHIVE_WRAPPER_END}
 )

src/sled/debugging/symbolize.cc

@@ -2,6 +2,7 @@
 #include "sled/lang/attributes.h"
 
 #ifdef _WIN32
+namespace sled {
 void
 InitializeSymbolizer(const char *argv0)
 {}
@@ -11,6 +12,7 @@ Symbolize(const void *pc, char *out, int out_size)
 {
     return false;
 }
+}// namespace sled
 #elif defined(__APPLE__)
 #include "symbolize_darwin.inc"
 #elif defined(__linux__)

src/sled/debugging/symbolize_elf.inc

@@ -1,140 +1,61 @@
-#include <array>
-#include <cxxabi.h>
-#include <dlfcn.h>
-#include <elf.h>
-#include <errno.h>
+#include "sled/log/log.h"
+#include <dwarf++.hh>
+#include <elf++.hh>
 #include <fcntl.h>
-#include <link.h>
-#include <sled/log/log.h>
-#include <sled/strings/utils.h>
-#include <sstream>
-#include <stdint.h>
 #include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <unistd.h>
 
 namespace sled {
 
-static constexpr char kTag[] = "symbolizer";
-static char *g_exe           = nullptr;
-
-static const uint64_t
-GetHex(const char *start, const char *end)
-{
-    uint64_t hex = 0;
-    for (const char *p = start; p < end; ++p) {
-        int ch = *p;
-        if (ch >= '0' && ch <= '9') {
-            hex = hex * 16 + (ch - '0');
-        } else if (ch >= 'a' && ch <= 'f') {
-            hex = hex * 16 + (ch - 'a' + 10);
-        } else if (ch >= 'A' && ch <= 'F') {
-            hex = hex * 16 + (ch - 'A' + 10);
-        } else {
-            break;
-        }
-    }
-
-    return hex;
-}
-
-static const uint64_t
-GetHex(const std::string &str)
-{
-    return GetHex(str.c_str(), str.c_str() + str.size());
-}
-
-struct ObjFile {
-    ObjFile() : filename(nullptr), start_addr(nullptr), end_addr(nullptr), offset(0), fd(-1), elf_type(-1)
-    {
-        memset(&elf_header, 0, sizeof(elf_header));
-        memset(phdrs.data(), 0, sizeof(ElfW(Phdr)) * phdrs.size());
-    }
-
-    char *filename;
-    const void *start_addr;
-    const void *end_addr;
-    uint64_t offset;
-
-    int fd;
-    int elf_type;
-    ElfW(Ehdr) elf_header;
-
-    std::array<ElfW(Phdr), 16> phdrs;
-};
-
-std::string
-ReadFullFile(int fd)
-{
-    std::stringstream ss;
-    char buf[4096];
-    ssize_t n;
-    while ((n = read(fd, buf, sizeof(buf))) > 0) { ss.write(buf, n); }
-    return ss.str();
-}
-
-bool
-ReadAddrMap()
-{
-    char maps_path[80];
-    snprintf(maps_path, sizeof(maps_path), "/proc/self/task/%d/maps", getpid());
-    int maps_fd;
-    do {
-        maps_fd = open(maps_path, O_RDONLY);
-    } while (maps_fd < 0 && errno == EINTR);
-
-    if (maps_fd < 0) {
-        LOGE(kTag, "open {} failed, {}", maps_path, strerror(errno));
-        return false;
-    }
-
-    std::string full_file = ReadFullFile(maps_fd);
-    auto lines            = sled::StrSplit(full_file, "\n");
-
-    // maps start_addr-end_addr permission offset dev inode pathname
-    for (const auto &line : lines) {
-        auto fields = sled::StrSplit(line, " \n\t", true);
-        if (fields.size() < 6) { continue; }
-        auto addrs = sled::StrSplit(fields[0], "-", false);
-
-        uint64_t start_addr = GetHex(addrs[0]);
-        uint64_t end_addr   = GetHex(addrs[1]);
-        uint64_t offset     = GetHex(fields[2]);
-        LOGD(kTag, "addr: {}-{} {} {} {}", start_addr, end_addr, offset, fields[1], fields[5]);
-    }
-
-    return true;
-}
-
-class Symbolizer {};
+static elf::elf *g_elf       = nullptr;
+static dwarf::dwarf *g_dwarf = nullptr;
 
 void
 InitializeSymbolizer(const char *argv0)
 {
-    if (g_exe) {
-        free(g_exe);
-        g_exe = nullptr;
-    }
+    if (g_elf) { return; }
+    int self_fd = open(argv0, O_RDONLY);
+    if (self_fd < 0) { return; }
+    g_elf   = new elf::elf(elf::create_mmap_loader(self_fd));
+    g_dwarf = new dwarf::dwarf(dwarf::elf::create_loader(*g_elf));
+}
 
-    if (argv0 && argv0[0] != '\0') { g_exe = strdup(argv0); }
+static bool
+FindPC(dwarf::taddr pc)
+{
+    return false;
 }
 
 bool
 Symbolize(const void *pc, char *out, int out_size)
 {
-    Dl_info info;
-    if (!dladdr(pc, &info)) { return false; }
-    if (info.dli_fname && out_size > 0) {
-        strncpy(out, info.dli_fname, out_size);
+    if (!g_elf || !g_dwarf) { return false; }
+    if (out_size <= 0) { return false; }
+    out[0] = '\0';
 
-        const auto end_pos = static_cast<size_t>(out_size) - 1;
-        if (out[end_pos] != '\0') {
-            // add ...
-            out[end_pos] = '\0';
-        }
+    union {
+        const void *void_pc;
+        dwarf::taddr pc_addr;
+    } u;
+
+    u.void_pc  = pc;
+    bool found = false;
+    for (auto &cu : g_dwarf->compilation_units()) {
+        try {
+            if (dwarf::die_pc_range(cu.root()).contains(u.pc_addr)) {
+                auto &lt  = cu.get_line_table();
+                auto iter = lt.find_address(u.pc_addr);
+                if (iter == lt.end()) {
+                    return false;
+                } else {
+                    LOGD("found line {}", iter->get_description());
+                }
+                found = true;
+                break;
+            }
+        } catch (...) {}
     }
 
-    return true;
+    return found;
 }
 }// namespace sled

src/sled/debugging/symbolize_test.cc

@@ -64,7 +64,7 @@ void_cast(TRet (TClass::*mem_func)(Args...))
 }
 
 // TODO: Support Linux
-#if defined(__APPLE__)
+// #if defined(__APPLE__)
 TEST_SUITE("Symbolize")
 {
     TEST_CASE("Trivial Function")
@@ -87,7 +87,8 @@ TEST_SUITE("Symbolize")
         CHECK_EQ(doctest::String("Class::StaticFunc()"), TrySymbolize(void_cast(&Class::StaticFunc)));
     }
 }
-#endif
+
+// #endif
 
 int
 main(int argc, char *argv[])

src/sled/experimental/design_patterns/dispatcher.h

@@ -0,0 +1,59 @@
+#ifndef SLED_EXP_DESIGN_PATTERNS_DISPATCHER_H
+#define SLED_EXP_DESIGN_PATTERNS_DISPATCHER_H
+
+#include "sled/synchronization/mutex.h"
+#include <memory>
+#include <set>
+
+namespace sled {
+namespace experimental {
+
+template<typename T>
+class Dispatcher {
+public:
+    enum class DispatchResult { kHandled, kNotFound };
+
+    struct Handler {
+        virtual ~Handler()                    = default;
+        virtual bool HandleMessage(const T &) = 0;
+        virtual bool OnMessage(T &&)          = 0;
+    };
+
+    virtual ~Dispatcher() = default;
+
+    void AddHandler(std::shared_ptr<Handler> handler)
+    {
+        if (!handler) { return; }
+        // sled::MutexLock lock(&mutex_);
+        sled::SharedMutexWriteLock lock(&rwlock_);
+        handlers_.insert(handler);
+    }
+
+    void RemoveHandler(std::shared_ptr<Handler> handler)
+    {
+        if (!handler) { return; }
+        // sled::MutexLock lock(&mutex_);
+        sled::SharedMutexWriteLock lock(&rwlock_);
+        handlers_.erase(handler);
+    }
+
+    DispatchResult Dispatch(const T &message)
+    {
+        // sled::MutexLock lock(&mutex_);
+        sled::SharedMutexReadLock lock(&rwlock_);
+        for (auto &handler : handlers_) {
+            if (handler->HandleMessage(message)) { return DispatchResult::kHandled; }
+        }
+        return DispatchResult::kNotFound;
+    }
+
+private:
+    std::set<std::shared_ptr<Handler>> handlers_;
+    sled::SharedMutex rwlock_;
+    // sled::Mutex mutex_;
+};
+
+}// namespace experimental
+
+}// namespace sled
+#endif// SLED_EXP_DESIGN_PATTERNS_DISPATCHER_H

src/sled/uri_fuzz.cc

@@ -4,6 +4,7 @@
 extern "C" int
 LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 {
+    if (size > 15) { return 1; }
     auto uri_or = sled::URI::ParseURI(std::string(reinterpret_cast<const char *>(data), size));
     if (!uri_or.ok()) { return 0; }
     auto uri = std::move(uri_or.value());