// 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::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