// dwarf_reader.cc -- parse dwarf2/3 debug information
-// Copyright 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+// Copyright (C) 2007-2019 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "gold.h"
#include <algorithm>
+#include <utility>
#include <vector>
#include "elfcpp_swap.h"
for (unsigned int i = 1; i < object->shnum(); ++i)
{
std::string name = object->section_name(i);
- if (name == ".debug_abbrev")
+ if (name == ".debug_abbrev" || name == ".zdebug_abbrev")
{
abbrev_shndx = i;
// Correct the offset. For incremental update links, we have a
for (unsigned int i = 1; i < object->shnum(); ++i)
{
std::string name = object->section_name(i);
- if (name == ".debug_ranges")
+ if (name == ".debug_ranges" || name == ".zdebug_ranges")
{
ranges_shndx = i;
this->output_section_offset_ = object->output_section_offset(i);
this->ranges_reloc_mapper_ = make_elf_reloc_mapper(object, symtab,
symtab_size);
this->ranges_reloc_mapper_->initialize(reloc_shndx, reloc_type);
+ this->reloc_type_ = reloc_type;
return true;
}
unsigned int shndx2 = 0;
if (this->ranges_reloc_mapper_ != NULL)
{
- shndx1 =
- this->ranges_reloc_mapper_->get_reloc_target(offset, &start);
- shndx2 =
- this->ranges_reloc_mapper_->get_reloc_target(offset + addr_size,
- &end);
+ shndx1 = this->lookup_reloc(offset, &start);
+ shndx2 = this->lookup_reloc(offset + addr_size, &end);
}
// End of list is marked by a pair of zeroes.
return ranges;
}
+// Look for a relocation at offset OFF in the range table,
+// and return the section index and offset of the target.
+
+unsigned int
+Dwarf_ranges_table::lookup_reloc(off_t off, off_t* target_off)
+{
+ off_t value;
+ unsigned int shndx =
+ this->ranges_reloc_mapper_->get_reloc_target(off, &value);
+ if (shndx == 0)
+ return 0;
+ if (this->reloc_type_ == elfcpp::SHT_REL)
+ *target_off += value;
+ else
+ *target_off = value;
+ return shndx;
+}
+
// class Dwarf_pubnames_table
-// Read the pubnames section SHNDX from the object file.
+// Read the pubnames section from the object file.
bool
-Dwarf_pubnames_table::read_section(Relobj* object, unsigned int shndx)
+Dwarf_pubnames_table::read_section(Relobj* object, const unsigned char* symtab,
+ off_t symtab_size)
{
section_size_type buffer_size;
+ unsigned int shndx = 0;
+ const char* name = this->is_pubtypes_ ? "pubtypes" : "pubnames";
+ const char* gnu_name = (this->is_pubtypes_
+ ? "gnu_pubtypes"
+ : "gnu_pubnames");
- // If we don't have relocations, shndx will be 0, and
- // we'll have to hunt for the .debug_pubnames/pubtypes section.
- if (shndx == 0)
+ for (unsigned int i = 1; i < object->shnum(); ++i)
{
- const char* name = (this->is_pubtypes_
- ? ".debug_pubtypes"
- : ".debug_pubnames");
- for (unsigned int i = 1; i < object->shnum(); ++i)
- {
- if (object->section_name(i) == name)
- {
- shndx = i;
- this->output_section_offset_ = object->output_section_offset(i);
- break;
- }
- }
- if (shndx == 0)
- return false;
+ std::string section_name = object->section_name(i);
+ const char* section_name_suffix = section_name.c_str();
+ if (is_prefix_of(".debug_", section_name_suffix))
+ section_name_suffix += 7;
+ else if (is_prefix_of(".zdebug_", section_name_suffix))
+ section_name_suffix += 8;
+ else
+ continue;
+ if (strcmp(section_name_suffix, name) == 0)
+ {
+ shndx = i;
+ break;
+ }
+ else if (strcmp(section_name_suffix, gnu_name) == 0)
+ {
+ shndx = i;
+ this->is_gnu_style_ = true;
+ break;
+ }
}
+ if (shndx == 0)
+ return false;
this->buffer_ = object->decompressed_section_contents(shndx,
&buffer_size,
if (this->buffer_ == NULL)
return false;
this->buffer_end_ = this->buffer_ + buffer_size;
+
+ // For incremental objects, we have no relocations.
+ if (object->is_incremental())
+ return true;
+
+ // Find the relocation section
+ unsigned int reloc_shndx = 0;
+ unsigned int reloc_type = 0;
+ for (unsigned int i = 0; i < object->shnum(); ++i)
+ {
+ reloc_type = object->section_type(i);
+ if ((reloc_type == elfcpp::SHT_REL
+ || reloc_type == elfcpp::SHT_RELA)
+ && object->section_info(i) == shndx)
+ {
+ reloc_shndx = i;
+ break;
+ }
+ }
+
+ this->reloc_mapper_ = make_elf_reloc_mapper(object, symtab, symtab_size);
+ this->reloc_mapper_->initialize(reloc_shndx, reloc_type);
+ this->reloc_type_ = reloc_type;
+
return true;
}
bool
Dwarf_pubnames_table::read_header(off_t offset)
{
- // Correct the offset. For incremental update links, we have a
- // relocated offset that is relative to the output section, but
- // here we need an offset relative to the input section.
- offset -= this->output_section_offset_;
+ // Make sure we have actually read the section.
+ gold_assert(this->buffer_ != NULL);
if (offset < 0 || offset + 14 >= this->buffer_end_ - this->buffer_)
return false;
const unsigned char* pinfo = this->buffer_ + offset;
// Read the unit_length field.
- uint32_t unit_length = this->dwinfo_->read_from_pointer<32>(pinfo);
+ uint64_t unit_length = this->dwinfo_->read_from_pointer<32>(pinfo);
pinfo += 4;
if (unit_length == 0xffffffff)
{
unit_length = this->dwinfo_->read_from_pointer<64>(pinfo);
+ this->unit_length_ = unit_length + 12;
pinfo += 8;
this->offset_size_ = 8;
}
else
- this->offset_size_ = 4;
+ {
+ this->unit_length_ = unit_length + 4;
+ this->offset_size_ = 4;
+ }
+ this->end_of_table_ = pinfo + unit_length;
+
+ // If unit_length is too big, maybe we should reject the whole table,
+ // but in cases we know about, it seems OK to assume that the table
+ // is valid through the actual end of the section.
+ if (this->end_of_table_ > this->buffer_end_)
+ this->end_of_table_ = this->buffer_end_;
// Check the version.
unsigned int version = this->dwinfo_->read_from_pointer<16>(pinfo);
if (version != 2)
return false;
+ this->reloc_mapper_->get_reloc_target(pinfo - this->buffer_,
+ &this->cu_offset_);
+
// Skip the debug_info_offset and debug_info_size fields.
pinfo += 2 * this->offset_size_;
// Read the next name from the set.
const char*
-Dwarf_pubnames_table::next_name()
+Dwarf_pubnames_table::next_name(uint8_t* flag_byte)
{
const unsigned char* pinfo = this->pinfo_;
- // Read the offset within the CU. If this is zero, we have reached
- // the end of the list.
- uint32_t offset;
- if (this->offset_size_ == 4)
- offset = this->dwinfo_->read_from_pointer<32>(&pinfo);
- else
- offset = this->dwinfo_->read_from_pointer<64>(&pinfo);
- if (offset == 0)
+ // Check for end of list. The table should be terminated by an
+ // entry containing nothing but a DIE offset of 0.
+ if (pinfo + this->offset_size_ >= this->end_of_table_)
return NULL;
+ // Skip the offset within the CU. If this is zero, but we're not
+ // at the end of the table, then we have a real pubnames entry
+ // whose DIE offset is 0 (likely to be a GCC bug). Since we
+ // don't actually use the DIE offset in building .gdb_index,
+ // it's harmless.
+ pinfo += this->offset_size_;
+
+ if (this->is_gnu_style_)
+ *flag_byte = *pinfo++;
+ else
+ *flag_byte = 0;
+
// Return a pointer to the string at the current location,
// and advance the pointer to the next entry.
const char* ret = reinterpret_cast<const char*>(pinfo);
break;
}
case elfcpp::DW_FORM_addr:
- case elfcpp::DW_FORM_ref_addr:
{
off_t sec_off;
if (this->dwinfo_->address_size() == 4)
ref_form = true;
break;
}
+ case elfcpp::DW_FORM_ref_addr:
+ {
+ off_t sec_off;
+ if (this->dwinfo_->ref_addr_size() == 4)
+ sec_off = this->dwinfo_->read_from_pointer<32>(&pattr);
+ else
+ sec_off = this->dwinfo_->read_from_pointer<64>(&pattr);
+ unsigned int shndx =
+ this->dwinfo_->lookup_reloc(attr_off, &sec_off);
+ attr_value.aux.shndx = shndx;
+ attr_value.val.refval = sec_off;
+ ref_form = true;
+ break;
+ }
case elfcpp::DW_FORM_block1:
attr_value.aux.blocklen = *pattr++;
attr_value.val.blockval = pattr;
pattr += this->dwinfo_->offset_size();
break;
case elfcpp::DW_FORM_addr:
- case elfcpp::DW_FORM_ref_addr:
pattr += this->dwinfo_->address_size();
break;
+ case elfcpp::DW_FORM_ref_addr:
+ pattr += this->dwinfo_->ref_addr_size();
+ break;
case elfcpp::DW_FORM_block1:
pattr += 1 + *pattr;
break;
for (unsigned int i = 1; i < this->object_->shnum(); ++i)
{
std::string name = object->section_name(i);
- if (name == ".debug_str")
+ if (name == ".debug_str" || name == ".zdebug_str")
{
string_shndx = i;
this->string_output_section_offset_ =
header_.min_insn_length = *lineptr;
lineptr += 1;
+ if (header_.version < 4)
+ header_.max_ops_per_insn = 1;
+ else
+ {
+ // DWARF 4 added the maximum_operations_per_instruction field.
+ header_.max_ops_per_insn = *lineptr;
+ lineptr += 1;
+ // TODO: Add support for values other than 1.
+ gold_assert(header_.max_ops_per_insn == 1);
+ }
+
header_.default_is_stmt = *lineptr;
lineptr += 1;
return "";
std::string result = this->format_file_lineno(*it);
+ gold_debug(DEBUG_LOCATION, "do_addr2line: canonical result: %s",
+ result.c_str());
if (other_lines != NULL)
- for (++it; it != offsets->end() && it->offset == offset; ++it)
- {
- if (it->line_num == -1)
- continue; // The end of a previous function.
- other_lines->push_back(this->format_file_lineno(*it));
- }
+ {
+ unsigned int last_file_num = it->file_num;
+ int last_line_num = it->line_num;
+ // Return up to 4 more locations from the beginning of the function
+ // for fuzzy matching.
+ for (++it; it != offsets->end(); ++it)
+ {
+ if (it->offset == offset && it->line_num == -1)
+ continue; // The end of a previous function.
+ if (it->line_num == -1)
+ break; // The end of the current function.
+ if (it->file_num != last_file_num || it->line_num != last_line_num)
+ {
+ other_lines->push_back(this->format_file_lineno(*it));
+ gold_debug(DEBUG_LOCATION, "do_addr2line: other: %s",
+ other_lines->back().c_str());
+ last_file_num = it->file_num;
+ last_line_num = it->line_num;
+ }
+ if (it->offset > offset && other_lines->size() >= 4)
+ break;
+ }
+ }
+
return result;
}