fix cursor crash
This commit is contained in:
tqcq
parent
60ff77ec1d
commit
2d12117cfb
@ -4,8 +4,8 @@
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#include "internal.hh"
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#include <stdexcept>
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#include <cstring>
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#include <stdexcept>
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using namespace std;
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@ -14,57 +14,56 @@ DWARFPP_BEGIN_NAMESPACE
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int64_t
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cursor::sleb128()
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{
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// Appendix C
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uint64_t result = 0;
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unsigned shift = 0;
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while (pos < sec->end) {
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uint8_t byte = *(uint8_t*)(pos++);
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result |= (uint64_t)(byte & 0x7f) << shift;
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shift += 7;
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if ((byte & 0x80) == 0) {
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if (shift < sizeof(result)*8 && (byte & 0x40))
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result |= -((uint64_t)1 << shift);
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return result;
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}
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// Appendix C
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uint64_t result = 0;
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unsigned shift = 0;
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while (pos < sec->end) {
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uint8_t byte = *(uint8_t *) (pos++);
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result |= (uint64_t) (byte & 0x7f) << shift;
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shift += 7;
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if ((byte & 0x80) == 0) {
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if (shift < sizeof(result) * 8 && (byte & 0x40)) result |= -((uint64_t) 1 << shift);
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return result;
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}
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underflow();
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return 0;
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}
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underflow();
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return 0;
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}
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shared_ptr<section>
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cursor::subsection()
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{
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// Section 7.4
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const char *begin = pos;
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section_length length = fixed<uword>();
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format fmt;
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if (length < 0xfffffff0) {
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fmt = format::dwarf32;
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length += sizeof(uword);
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} else if (length == 0xffffffff) {
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length = fixed<uint64_t>();
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fmt = format::dwarf64;
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length += sizeof(uword) + sizeof(uint64_t);
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} else {
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throw format_error("initial length has reserved value");
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}
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pos = begin + length;
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return make_shared<section>(sec->type, begin, length, sec->ord, fmt);
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// Section 7.4
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const char *begin = pos;
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section_length length = fixed<uword>();
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format fmt;
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if (length < 0xfffffff0) {
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fmt = format::dwarf32;
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length += sizeof(uword);
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} else if (length == 0xffffffff) {
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length = fixed<uint64_t>();
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fmt = format::dwarf64;
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length += sizeof(uword) + sizeof(uint64_t);
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} else {
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throw format_error("initial length has reserved value");
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}
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pos = begin + length;
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return make_shared<section>(sec->type, begin, length, sec->ord, fmt);
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}
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void
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cursor::skip_initial_length()
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{
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switch (sec->fmt) {
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case format::dwarf32:
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pos += sizeof(uword);
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break;
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case format::dwarf64:
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pos += sizeof(uword) + sizeof(uint64_t);
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break;
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default:
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throw logic_error("cannot skip initial length with unknown format");
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}
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switch (sec->fmt) {
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case format::dwarf32:
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pos += sizeof(uword);
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break;
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case format::dwarf64:
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pos += sizeof(uword) + sizeof(uint64_t);
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break;
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default:
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throw logic_error("cannot skip initial length with unknown format");
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}
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}
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void
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@ -76,132 +75,128 @@ cursor::skip_unit_type()
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section_offset
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cursor::offset()
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{
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switch (sec->fmt) {
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case format::dwarf32:
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return fixed<uint32_t>();
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case format::dwarf64:
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return fixed<uint64_t>();
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default:
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throw logic_error("cannot read offset with unknown format");
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}
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switch (sec->fmt) {
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case format::dwarf32:
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return fixed<uint32_t>();
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case format::dwarf64:
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return fixed<uint64_t>();
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default:
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throw logic_error("cannot read offset with unknown format");
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}
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}
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void
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cursor::string(std::string &out)
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{
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size_t size;
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const char *p = this->cstr(&size);
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out.resize(size);
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memmove(&out.front(), p, size);
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size_t size;
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const char *p = this->cstr(&size);
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// out.resize(size);
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// memmove(&out.front(), p, size);
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out = std::string(p, p + size);
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}
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const char *
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cursor::cstr(size_t *size_out)
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{
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// Scan string size
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const char *p = pos;
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while (pos < sec->end && *pos)
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pos++;
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if (pos == sec->end)
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throw format_error("unterminated string");
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if (size_out)
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*size_out = pos - p;
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pos++;
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return p;
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// Scan string size
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const char *p = pos;
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while (pos < sec->end && *pos) pos++;
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if (pos == sec->end) throw format_error("unterminated string");
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if (size_out) *size_out = pos - p;
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pos++;
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return p;
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}
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void
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cursor::skip_form(DW_FORM form)
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{
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section_offset tmp;
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section_offset tmp;
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// Section 7.5.4
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switch (form) {
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case DW_FORM::addr:
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pos += sec->addr_size;
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break;
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case DW_FORM::sec_offset:
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case DW_FORM::ref_addr:
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case DW_FORM::strp:
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switch (sec->fmt) {
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case format::dwarf32:
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pos += 4;
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break;
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case format::dwarf64:
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pos += 8;
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break;
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case format::unknown:
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throw logic_error("cannot read form with unknown format");
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}
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break;
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// size+data forms
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case DW_FORM::block1:
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tmp = fixed<ubyte>();
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pos += tmp;
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break;
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case DW_FORM::block2:
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tmp = fixed<uhalf>();
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pos += tmp;
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break;
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case DW_FORM::block4:
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tmp = fixed<uword>();
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pos += tmp;
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break;
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case DW_FORM::block:
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case DW_FORM::exprloc:
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tmp = uleb128();
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pos += tmp;
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break;
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// fixed-length forms
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case DW_FORM::flag_present:
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break;
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case DW_FORM::flag:
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case DW_FORM::data1:
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case DW_FORM::ref1:
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pos += 1;
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break;
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case DW_FORM::data2:
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case DW_FORM::ref2:
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pos += 2;
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break;
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case DW_FORM::data4:
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case DW_FORM::ref4:
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pos += 4;
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break;
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case DW_FORM::data8:
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case DW_FORM::ref_sig8:
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pos += 8;
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break;
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// variable-length forms
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case DW_FORM::sdata:
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case DW_FORM::udata:
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case DW_FORM::ref_udata:
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while (pos < sec->end && (*(uint8_t*)pos & 0x80))
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pos++;
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pos++;
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break;
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case DW_FORM::string:
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while (pos < sec->end && *pos)
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pos++;
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pos++;
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break;
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case DW_FORM::indirect:
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skip_form((DW_FORM)uleb128());
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break;
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default:
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throw format_error("unknown form " + to_string(form));
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// Section 7.5.4
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switch (form) {
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case DW_FORM::addr:
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pos += sec->addr_size;
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break;
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case DW_FORM::sec_offset:
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case DW_FORM::ref_addr:
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case DW_FORM::strp:
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switch (sec->fmt) {
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case format::dwarf32:
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pos += 4;
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break;
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case format::dwarf64:
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pos += 8;
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break;
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case format::unknown:
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throw logic_error("cannot read form with unknown format");
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}
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break;
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// size+data forms
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case DW_FORM::block1:
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tmp = fixed<ubyte>();
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pos += tmp;
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break;
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case DW_FORM::block2:
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tmp = fixed<uhalf>();
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pos += tmp;
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break;
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case DW_FORM::block4:
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tmp = fixed<uword>();
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pos += tmp;
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break;
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case DW_FORM::block:
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case DW_FORM::exprloc:
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tmp = uleb128();
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pos += tmp;
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break;
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// fixed-length forms
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case DW_FORM::flag_present:
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break;
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case DW_FORM::flag:
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case DW_FORM::data1:
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case DW_FORM::ref1:
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pos += 1;
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break;
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case DW_FORM::data2:
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case DW_FORM::ref2:
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pos += 2;
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break;
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case DW_FORM::data4:
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case DW_FORM::ref4:
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pos += 4;
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break;
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case DW_FORM::data8:
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case DW_FORM::ref_sig8:
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pos += 8;
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break;
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// variable-length forms
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case DW_FORM::sdata:
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case DW_FORM::udata:
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case DW_FORM::ref_udata:
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while (pos < sec->end && (*(uint8_t *) pos & 0x80)) pos++;
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pos++;
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break;
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case DW_FORM::string:
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while (pos < sec->end && *pos) pos++;
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pos++;
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break;
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case DW_FORM::indirect:
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skip_form((DW_FORM) uleb128());
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break;
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default:
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throw format_error("unknown form " + to_string(form));
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}
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}
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void
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cursor::underflow()
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{
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throw underflow_error("cannot read past end of DWARF section");
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throw underflow_error("cannot read past end of DWARF section");
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}
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DWARFPP_END_NAMESPACE
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