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-rw-r--r--toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2reader.cc2815
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diff --git a/toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2reader.cc b/toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2reader.cc
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index 0000000000..3e6a3e89f4
--- /dev/null
+++ b/toolkit/crashreporter/google-breakpad/src/common/dwarf/dwarf2reader.cc
@@ -0,0 +1,2815 @@
+// Copyright (c) 2010 Google Inc. All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// CFI reader author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
+
+// Implementation of dwarf2reader::LineInfo, dwarf2reader::CompilationUnit,
+// and dwarf2reader::CallFrameInfo. See dwarf2reader.h for details.
+
+#include "common/dwarf/dwarf2reader.h"
+
+#include <assert.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <map>
+#include <memory>
+#include <stack>
+#include <string>
+#include <utility>
+
+#include <sys/stat.h>
+
+#include "common/dwarf/bytereader-inl.h"
+#include "common/dwarf/bytereader.h"
+#include "common/dwarf/line_state_machine.h"
+#include "common/using_std_string.h"
+
+namespace dwarf2reader {
+
+CompilationUnit::CompilationUnit(const string& path,
+ const SectionMap& sections, uint64 offset,
+ ByteReader* reader, Dwarf2Handler* handler)
+ : path_(path), offset_from_section_start_(offset), reader_(reader),
+ sections_(sections), handler_(handler), abbrevs_(),
+ string_buffer_(NULL), string_buffer_length_(0),
+ str_offsets_buffer_(NULL), str_offsets_buffer_length_(0),
+ addr_buffer_(NULL), addr_buffer_length_(0),
+ is_split_dwarf_(false), dwo_id_(0), dwo_name_(),
+ skeleton_dwo_id_(0), ranges_base_(0), addr_base_(0),
+ have_checked_for_dwp_(false), dwp_path_(),
+ dwp_byte_reader_(), dwp_reader_() {}
+
+// Initialize a compilation unit from a .dwo or .dwp file.
+// In this case, we need the .debug_addr section from the
+// executable file that contains the corresponding skeleton
+// compilation unit. We also inherit the Dwarf2Handler from
+// the executable file, and call it as if we were still
+// processing the original compilation unit.
+
+void CompilationUnit::SetSplitDwarf(const uint8_t* addr_buffer,
+ uint64 addr_buffer_length,
+ uint64 addr_base,
+ uint64 ranges_base,
+ uint64 dwo_id) {
+ is_split_dwarf_ = true;
+ addr_buffer_ = addr_buffer;
+ addr_buffer_length_ = addr_buffer_length;
+ addr_base_ = addr_base;
+ ranges_base_ = ranges_base;
+ skeleton_dwo_id_ = dwo_id;
+}
+
+// Read a DWARF2/3 abbreviation section.
+// Each abbrev consists of a abbreviation number, a tag, a byte
+// specifying whether the tag has children, and a list of
+// attribute/form pairs.
+// The list of forms is terminated by a 0 for the attribute, and a
+// zero for the form. The entire abbreviation section is terminated
+// by a zero for the code.
+
+void CompilationUnit::ReadAbbrevs() {
+ if (abbrevs_)
+ return;
+
+ // First get the debug_abbrev section. ".debug_abbrev" is the name
+ // recommended in the DWARF spec, and used on Linux;
+ // "__debug_abbrev" is the name used in Mac OS X Mach-O files.
+ SectionMap::const_iterator iter = sections_.find(".debug_abbrev");
+ if (iter == sections_.end())
+ iter = sections_.find("__debug_abbrev");
+ assert(iter != sections_.end());
+
+ abbrevs_ = new std::vector<Abbrev>;
+ abbrevs_->resize(1);
+
+ // The only way to check whether we are reading over the end of the
+ // buffer would be to first compute the size of the leb128 data by
+ // reading it, then go back and read it again.
+ const uint8_t *abbrev_start = iter->second.first +
+ header_.abbrev_offset;
+ const uint8_t *abbrevptr = abbrev_start;
+#ifndef NDEBUG
+ const uint64 abbrev_length = iter->second.second - header_.abbrev_offset;
+#endif
+
+ while (1) {
+ CompilationUnit::Abbrev abbrev;
+ size_t len;
+ const uint64 number = reader_->ReadUnsignedLEB128(abbrevptr, &len);
+
+ if (number == 0)
+ break;
+ abbrev.number = number;
+ abbrevptr += len;
+
+ assert(abbrevptr < abbrev_start + abbrev_length);
+ const uint64 tag = reader_->ReadUnsignedLEB128(abbrevptr, &len);
+ abbrevptr += len;
+ abbrev.tag = static_cast<enum DwarfTag>(tag);
+
+ assert(abbrevptr < abbrev_start + abbrev_length);
+ abbrev.has_children = reader_->ReadOneByte(abbrevptr);
+ abbrevptr += 1;
+
+ assert(abbrevptr < abbrev_start + abbrev_length);
+
+ while (1) {
+ const uint64 nametemp = reader_->ReadUnsignedLEB128(abbrevptr, &len);
+ abbrevptr += len;
+
+ assert(abbrevptr < abbrev_start + abbrev_length);
+ const uint64 formtemp = reader_->ReadUnsignedLEB128(abbrevptr, &len);
+ abbrevptr += len;
+ if (nametemp == 0 && formtemp == 0)
+ break;
+
+ const enum DwarfAttribute name =
+ static_cast<enum DwarfAttribute>(nametemp);
+ const enum DwarfForm form = static_cast<enum DwarfForm>(formtemp);
+ abbrev.attributes.push_back(std::make_pair(name, form));
+ }
+ assert(abbrev.number == abbrevs_->size());
+ abbrevs_->push_back(abbrev);
+ }
+}
+
+// Skips a single DIE's attributes.
+const uint8_t *CompilationUnit::SkipDIE(const uint8_t* start,
+ const Abbrev& abbrev) {
+ for (AttributeList::const_iterator i = abbrev.attributes.begin();
+ i != abbrev.attributes.end();
+ i++) {
+ start = SkipAttribute(start, i->second);
+ }
+ return start;
+}
+
+// Skips a single attribute form's data.
+const uint8_t *CompilationUnit::SkipAttribute(const uint8_t *start,
+ enum DwarfForm form) {
+ size_t len;
+
+ switch (form) {
+ case DW_FORM_indirect:
+ form = static_cast<enum DwarfForm>(reader_->ReadUnsignedLEB128(start,
+ &len));
+ start += len;
+ return SkipAttribute(start, form);
+
+ case DW_FORM_flag_present:
+ return start;
+ case DW_FORM_data1:
+ case DW_FORM_flag:
+ case DW_FORM_ref1:
+ return start + 1;
+ case DW_FORM_ref2:
+ case DW_FORM_data2:
+ return start + 2;
+ case DW_FORM_ref4:
+ case DW_FORM_data4:
+ return start + 4;
+ case DW_FORM_ref8:
+ case DW_FORM_data8:
+ case DW_FORM_ref_sig8:
+ return start + 8;
+ case DW_FORM_string:
+ return start + strlen(reinterpret_cast<const char *>(start)) + 1;
+ case DW_FORM_udata:
+ case DW_FORM_ref_udata:
+ case DW_FORM_GNU_str_index:
+ case DW_FORM_GNU_addr_index:
+ reader_->ReadUnsignedLEB128(start, &len);
+ return start + len;
+
+ case DW_FORM_sdata:
+ reader_->ReadSignedLEB128(start, &len);
+ return start + len;
+ case DW_FORM_addr:
+ return start + reader_->AddressSize();
+ case DW_FORM_ref_addr:
+ // DWARF2 and 3/4 differ on whether ref_addr is address size or
+ // offset size.
+ assert(header_.version >= 2);
+ if (header_.version == 2) {
+ return start + reader_->AddressSize();
+ } else if (header_.version >= 3) {
+ return start + reader_->OffsetSize();
+ }
+ break;
+
+ case DW_FORM_block1:
+ return start + 1 + reader_->ReadOneByte(start);
+ case DW_FORM_block2:
+ return start + 2 + reader_->ReadTwoBytes(start);
+ case DW_FORM_block4:
+ return start + 4 + reader_->ReadFourBytes(start);
+ case DW_FORM_block:
+ case DW_FORM_exprloc: {
+ uint64 size = reader_->ReadUnsignedLEB128(start, &len);
+ return start + size + len;
+ }
+ case DW_FORM_strp:
+ case DW_FORM_sec_offset:
+ return start + reader_->OffsetSize();
+ }
+ fprintf(stderr,"Unhandled form type");
+ return NULL;
+}
+
+// Read a DWARF2/3 header.
+// The header is variable length in DWARF3 (and DWARF2 as extended by
+// most compilers), and consists of an length field, a version number,
+// the offset in the .debug_abbrev section for our abbrevs, and an
+// address size.
+void CompilationUnit::ReadHeader() {
+ const uint8_t *headerptr = buffer_;
+ size_t initial_length_size;
+
+ assert(headerptr + 4 < buffer_ + buffer_length_);
+ const uint64 initial_length
+ = reader_->ReadInitialLength(headerptr, &initial_length_size);
+ headerptr += initial_length_size;
+ header_.length = initial_length;
+
+ assert(headerptr + 2 < buffer_ + buffer_length_);
+ header_.version = reader_->ReadTwoBytes(headerptr);
+ headerptr += 2;
+
+ assert(headerptr + reader_->OffsetSize() < buffer_ + buffer_length_);
+ header_.abbrev_offset = reader_->ReadOffset(headerptr);
+ headerptr += reader_->OffsetSize();
+
+ // Compare against less than or equal because this may be the last
+ // section in the file.
+ assert(headerptr + 1 <= buffer_ + buffer_length_);
+ header_.address_size = reader_->ReadOneByte(headerptr);
+ reader_->SetAddressSize(header_.address_size);
+ headerptr += 1;
+
+ after_header_ = headerptr;
+
+ // This check ensures that we don't have to do checking during the
+ // reading of DIEs. header_.length does not include the size of the
+ // initial length.
+ assert(buffer_ + initial_length_size + header_.length <=
+ buffer_ + buffer_length_);
+}
+
+uint64 CompilationUnit::Start() {
+ // First get the debug_info section. ".debug_info" is the name
+ // recommended in the DWARF spec, and used on Linux; "__debug_info"
+ // is the name used in Mac OS X Mach-O files.
+ SectionMap::const_iterator iter = sections_.find(".debug_info");
+ if (iter == sections_.end())
+ iter = sections_.find("__debug_info");
+ assert(iter != sections_.end());
+
+ // Set up our buffer
+ buffer_ = iter->second.first + offset_from_section_start_;
+ buffer_length_ = iter->second.second - offset_from_section_start_;
+
+ // Read the header
+ ReadHeader();
+
+ // Figure out the real length from the end of the initial length to
+ // the end of the compilation unit, since that is the value we
+ // return.
+ uint64 ourlength = header_.length;
+ if (reader_->OffsetSize() == 8)
+ ourlength += 12;
+ else
+ ourlength += 4;
+
+ // See if the user wants this compilation unit, and if not, just return.
+ if (!handler_->StartCompilationUnit(offset_from_section_start_,
+ reader_->AddressSize(),
+ reader_->OffsetSize(),
+ header_.length,
+ header_.version))
+ return ourlength;
+
+ // Otherwise, continue by reading our abbreviation entries.
+ ReadAbbrevs();
+
+ // Set the string section if we have one. ".debug_str" is the name
+ // recommended in the DWARF spec, and used on Linux; "__debug_str"
+ // is the name used in Mac OS X Mach-O files.
+ iter = sections_.find(".debug_str");
+ if (iter == sections_.end())
+ iter = sections_.find("__debug_str");
+ if (iter != sections_.end()) {
+ string_buffer_ = iter->second.first;
+ string_buffer_length_ = iter->second.second;
+ }
+
+ // Set the string offsets section if we have one.
+ iter = sections_.find(".debug_str_offsets");
+ if (iter != sections_.end()) {
+ str_offsets_buffer_ = iter->second.first;
+ str_offsets_buffer_length_ = iter->second.second;
+ }
+
+ // Set the address section if we have one.
+ iter = sections_.find(".debug_addr");
+ if (iter != sections_.end()) {
+ addr_buffer_ = iter->second.first;
+ addr_buffer_length_ = iter->second.second;
+ }
+
+ // Now that we have our abbreviations, start processing DIE's.
+ ProcessDIEs();
+
+ // If this is a skeleton compilation unit generated with split DWARF,
+ // and the client needs the full debug info, we need to find the full
+ // compilation unit in a .dwo or .dwp file.
+ if (!is_split_dwarf_
+ && dwo_name_ != NULL
+ && handler_->NeedSplitDebugInfo())
+ ProcessSplitDwarf();
+
+ return ourlength;
+}
+
+// If one really wanted, you could merge SkipAttribute and
+// ProcessAttribute
+// This is all boring data manipulation and calling of the handler.
+const uint8_t *CompilationUnit::ProcessAttribute(
+ uint64 dieoffset, const uint8_t *start, enum DwarfAttribute attr,
+ enum DwarfForm form) {
+ size_t len;
+
+ switch (form) {
+ // DW_FORM_indirect is never used because it is such a space
+ // waster.
+ case DW_FORM_indirect:
+ form = static_cast<enum DwarfForm>(reader_->ReadUnsignedLEB128(start,
+ &len));
+ start += len;
+ return ProcessAttribute(dieoffset, start, attr, form);
+
+ case DW_FORM_flag_present:
+ ProcessAttributeUnsigned(dieoffset, attr, form, 1);
+ return start;
+ case DW_FORM_data1:
+ case DW_FORM_flag:
+ ProcessAttributeUnsigned(dieoffset, attr, form,
+ reader_->ReadOneByte(start));
+ return start + 1;
+ case DW_FORM_data2:
+ ProcessAttributeUnsigned(dieoffset, attr, form,
+ reader_->ReadTwoBytes(start));
+ return start + 2;
+ case DW_FORM_data4:
+ ProcessAttributeUnsigned(dieoffset, attr, form,
+ reader_->ReadFourBytes(start));
+ return start + 4;
+ case DW_FORM_data8:
+ ProcessAttributeUnsigned(dieoffset, attr, form,
+ reader_->ReadEightBytes(start));
+ return start + 8;
+ case DW_FORM_string: {
+ const char *str = reinterpret_cast<const char *>(start);
+ ProcessAttributeString(dieoffset, attr, form, str);
+ return start + strlen(str) + 1;
+ }
+ case DW_FORM_udata:
+ ProcessAttributeUnsigned(dieoffset, attr, form,
+ reader_->ReadUnsignedLEB128(start, &len));
+ return start + len;
+
+ case DW_FORM_sdata:
+ ProcessAttributeSigned(dieoffset, attr, form,
+ reader_->ReadSignedLEB128(start, &len));
+ return start + len;
+ case DW_FORM_addr:
+ ProcessAttributeUnsigned(dieoffset, attr, form,
+ reader_->ReadAddress(start));
+ return start + reader_->AddressSize();
+ case DW_FORM_sec_offset:
+ ProcessAttributeUnsigned(dieoffset, attr, form,
+ reader_->ReadOffset(start));
+ return start + reader_->OffsetSize();
+
+ case DW_FORM_ref1:
+ handler_->ProcessAttributeReference(dieoffset, attr, form,
+ reader_->ReadOneByte(start)
+ + offset_from_section_start_);
+ return start + 1;
+ case DW_FORM_ref2:
+ handler_->ProcessAttributeReference(dieoffset, attr, form,
+ reader_->ReadTwoBytes(start)
+ + offset_from_section_start_);
+ return start + 2;
+ case DW_FORM_ref4:
+ handler_->ProcessAttributeReference(dieoffset, attr, form,
+ reader_->ReadFourBytes(start)
+ + offset_from_section_start_);
+ return start + 4;
+ case DW_FORM_ref8:
+ handler_->ProcessAttributeReference(dieoffset, attr, form,
+ reader_->ReadEightBytes(start)
+ + offset_from_section_start_);
+ return start + 8;
+ case DW_FORM_ref_udata:
+ handler_->ProcessAttributeReference(dieoffset, attr, form,
+ reader_->ReadUnsignedLEB128(start,
+ &len)
+ + offset_from_section_start_);
+ return start + len;
+ case DW_FORM_ref_addr:
+ // DWARF2 and 3/4 differ on whether ref_addr is address size or
+ // offset size.
+ assert(header_.version >= 2);
+ if (header_.version == 2) {
+ handler_->ProcessAttributeReference(dieoffset, attr, form,
+ reader_->ReadAddress(start));
+ return start + reader_->AddressSize();
+ } else if (header_.version >= 3) {
+ handler_->ProcessAttributeReference(dieoffset, attr, form,
+ reader_->ReadOffset(start));
+ return start + reader_->OffsetSize();
+ }
+ break;
+ case DW_FORM_ref_sig8:
+ handler_->ProcessAttributeSignature(dieoffset, attr, form,
+ reader_->ReadEightBytes(start));
+ return start + 8;
+
+ case DW_FORM_block1: {
+ uint64 datalen = reader_->ReadOneByte(start);
+ handler_->ProcessAttributeBuffer(dieoffset, attr, form, start + 1,
+ datalen);
+ return start + 1 + datalen;
+ }
+ case DW_FORM_block2: {
+ uint64 datalen = reader_->ReadTwoBytes(start);
+ handler_->ProcessAttributeBuffer(dieoffset, attr, form, start + 2,
+ datalen);
+ return start + 2 + datalen;
+ }
+ case DW_FORM_block4: {
+ uint64 datalen = reader_->ReadFourBytes(start);
+ handler_->ProcessAttributeBuffer(dieoffset, attr, form, start + 4,
+ datalen);
+ return start + 4 + datalen;
+ }
+ case DW_FORM_block:
+ case DW_FORM_exprloc: {
+ uint64 datalen = reader_->ReadUnsignedLEB128(start, &len);
+ handler_->ProcessAttributeBuffer(dieoffset, attr, form, start + len,
+ datalen);
+ return start + datalen + len;
+ }
+ case DW_FORM_strp: {
+ assert(string_buffer_ != NULL);
+
+ const uint64 offset = reader_->ReadOffset(start);
+ assert(string_buffer_ + offset < string_buffer_ + string_buffer_length_);
+
+ const char *str = reinterpret_cast<const char *>(string_buffer_ + offset);
+ ProcessAttributeString(dieoffset, attr, form, str);
+ return start + reader_->OffsetSize();
+ }
+
+ case DW_FORM_GNU_str_index: {
+ uint64 str_index = reader_->ReadUnsignedLEB128(start, &len);
+ const uint8_t* offset_ptr =
+ str_offsets_buffer_ + str_index * reader_->OffsetSize();
+ const uint64 offset = reader_->ReadOffset(offset_ptr);
+ if (offset >= string_buffer_length_) {
+ return NULL;
+ }
+
+ const char* str = reinterpret_cast<const char *>(string_buffer_) + offset;
+ ProcessAttributeString(dieoffset, attr, form, str);
+ return start + len;
+ break;
+ }
+ case DW_FORM_GNU_addr_index: {
+ uint64 addr_index = reader_->ReadUnsignedLEB128(start, &len);
+ const uint8_t* addr_ptr =
+ addr_buffer_ + addr_base_ + addr_index * reader_->AddressSize();
+ ProcessAttributeUnsigned(dieoffset, attr, form,
+ reader_->ReadAddress(addr_ptr));
+ return start + len;
+ }
+ }
+ fprintf(stderr, "Unhandled form type\n");
+ return NULL;
+}
+
+const uint8_t *CompilationUnit::ProcessDIE(uint64 dieoffset,
+ const uint8_t *start,
+ const Abbrev& abbrev) {
+ for (AttributeList::const_iterator i = abbrev.attributes.begin();
+ i != abbrev.attributes.end();
+ i++) {
+ start = ProcessAttribute(dieoffset, start, i->first, i->second);
+ }
+
+ // If this is a compilation unit in a split DWARF object, verify that
+ // the dwo_id matches. If it does not match, we will ignore this
+ // compilation unit.
+ if (abbrev.tag == DW_TAG_compile_unit
+ && is_split_dwarf_
+ && dwo_id_ != skeleton_dwo_id_) {
+ return NULL;
+ }
+
+ return start;
+}
+
+void CompilationUnit::ProcessDIEs() {
+ const uint8_t *dieptr = after_header_;
+ size_t len;
+
+ // lengthstart is the place the length field is based on.
+ // It is the point in the header after the initial length field
+ const uint8_t *lengthstart = buffer_;
+
+ // In 64 bit dwarf, the initial length is 12 bytes, because of the
+ // 0xffffffff at the start.
+ if (reader_->OffsetSize() == 8)
+ lengthstart += 12;
+ else
+ lengthstart += 4;
+
+ std::stack<uint64> die_stack;
+
+ while (dieptr < (lengthstart + header_.length)) {
+ // We give the user the absolute offset from the beginning of
+ // debug_info, since they need it to deal with ref_addr forms.
+ uint64 absolute_offset = (dieptr - buffer_) + offset_from_section_start_;
+
+ uint64 abbrev_num = reader_->ReadUnsignedLEB128(dieptr, &len);
+
+ dieptr += len;
+
+ // Abbrev == 0 represents the end of a list of children, or padding
+ // at the end of the compilation unit.
+ if (abbrev_num == 0) {
+ if (die_stack.size() == 0)
+ // If it is padding, then we are done with the compilation unit's DIEs.
+ return;
+ const uint64 offset = die_stack.top();
+ die_stack.pop();
+ handler_->EndDIE(offset);
+ continue;
+ }
+
+ const Abbrev& abbrev = abbrevs_->at(static_cast<size_t>(abbrev_num));
+ const enum DwarfTag tag = abbrev.tag;
+ if (!handler_->StartDIE(absolute_offset, tag)) {
+ dieptr = SkipDIE(dieptr, abbrev);
+ } else {
+ dieptr = ProcessDIE(absolute_offset, dieptr, abbrev);
+ }
+
+ if (abbrev.has_children) {
+ die_stack.push(absolute_offset);
+ } else {
+ handler_->EndDIE(absolute_offset);
+ }
+ }
+}
+
+// Check for a valid ELF file and return the Address size.
+// Returns 0 if not a valid ELF file.
+inline int GetElfWidth(const ElfReader& elf) {
+ if (elf.IsElf32File())
+ return 4;
+ if (elf.IsElf64File())
+ return 8;
+ return 0;
+}
+
+void CompilationUnit::ProcessSplitDwarf() {
+ struct stat statbuf;
+ if (!have_checked_for_dwp_) {
+ // Look for a .dwp file in the same directory as the executable.
+ have_checked_for_dwp_ = true;
+ string dwp_suffix(".dwp");
+ dwp_path_ = path_ + dwp_suffix;
+ if (stat(dwp_path_.c_str(), &statbuf) != 0) {
+ // Fall back to a split .debug file in the same directory.
+ string debug_suffix(".debug");
+ dwp_path_ = path_;
+ size_t found = path_.rfind(debug_suffix);
+ if (found + debug_suffix.length() == path_.length())
+ dwp_path_ = dwp_path_.replace(found, debug_suffix.length(), dwp_suffix);
+ }
+ if (stat(dwp_path_.c_str(), &statbuf) == 0) {
+ ElfReader* elf = new ElfReader(dwp_path_);
+ int width = GetElfWidth(*elf);
+ if (width != 0) {
+ dwp_byte_reader_.reset(new ByteReader(reader_->GetEndianness()));
+ dwp_byte_reader_->SetAddressSize(width);
+ dwp_reader_.reset(new DwpReader(*dwp_byte_reader_, elf));
+ dwp_reader_->Initialize();
+ } else {
+ delete elf;
+ }
+ }
+ }
+ bool found_in_dwp = false;
+ if (dwp_reader_) {
+ // If we have a .dwp file, read the debug sections for the requested CU.
+ SectionMap sections;
+ dwp_reader_->ReadDebugSectionsForCU(dwo_id_, &sections);
+ if (!sections.empty()) {
+ found_in_dwp = true;
+ CompilationUnit dwp_comp_unit(dwp_path_, sections, 0,
+ dwp_byte_reader_.get(), handler_);
+ dwp_comp_unit.SetSplitDwarf(addr_buffer_, addr_buffer_length_, addr_base_,
+ ranges_base_, dwo_id_);
+ dwp_comp_unit.Start();
+ }
+ }
+ if (!found_in_dwp) {
+ // If no .dwp file, try to open the .dwo file.
+ if (stat(dwo_name_, &statbuf) == 0) {
+ ElfReader elf(dwo_name_);
+ int width = GetElfWidth(elf);
+ if (width != 0) {
+ ByteReader reader(ENDIANNESS_LITTLE);
+ reader.SetAddressSize(width);
+ SectionMap sections;
+ ReadDebugSectionsFromDwo(&elf, &sections);
+ CompilationUnit dwo_comp_unit(dwo_name_, sections, 0, &reader,
+ handler_);
+ dwo_comp_unit.SetSplitDwarf(addr_buffer_, addr_buffer_length_,
+ addr_base_, ranges_base_, dwo_id_);
+ dwo_comp_unit.Start();
+ }
+ }
+ }
+}
+
+void CompilationUnit::ReadDebugSectionsFromDwo(ElfReader* elf_reader,
+ SectionMap* sections) {
+ static const char* const section_names[] = {
+ ".debug_abbrev",
+ ".debug_info",
+ ".debug_str_offsets",
+ ".debug_str"
+ };
+ for (unsigned int i = 0u;
+ i < sizeof(section_names)/sizeof(*(section_names)); ++i) {
+ string base_name = section_names[i];
+ string dwo_name = base_name + ".dwo";
+ size_t section_size;
+ const char* section_data = elf_reader->GetSectionByName(dwo_name,
+ &section_size);
+ if (section_data != NULL)
+ sections->insert(std::make_pair(
+ base_name, std::make_pair(
+ reinterpret_cast<const uint8_t *>(section_data),
+ section_size)));
+ }
+}
+
+DwpReader::DwpReader(const ByteReader& byte_reader, ElfReader* elf_reader)
+ : elf_reader_(elf_reader), byte_reader_(byte_reader),
+ cu_index_(NULL), cu_index_size_(0), string_buffer_(NULL),
+ string_buffer_size_(0), version_(0), ncolumns_(0), nunits_(0),
+ nslots_(0), phash_(NULL), pindex_(NULL), shndx_pool_(NULL),
+ offset_table_(NULL), size_table_(NULL), abbrev_data_(NULL),
+ abbrev_size_(0), info_data_(NULL), info_size_(0),
+ str_offsets_data_(NULL), str_offsets_size_(0) {}
+
+DwpReader::~DwpReader() {
+ if (elf_reader_) delete elf_reader_;
+}
+
+void DwpReader::Initialize() {
+ cu_index_ = elf_reader_->GetSectionByName(".debug_cu_index",
+ &cu_index_size_);
+ if (cu_index_ == NULL) {
+ return;
+ }
+ // The .debug_str.dwo section is shared by all CUs in the file.
+ string_buffer_ = elf_reader_->GetSectionByName(".debug_str.dwo",
+ &string_buffer_size_);
+
+ version_ = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(cu_index_));
+
+ if (version_ == 1) {
+ nslots_ = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(cu_index_)
+ + 3 * sizeof(uint32));
+ phash_ = cu_index_ + 4 * sizeof(uint32);
+ pindex_ = phash_ + nslots_ * sizeof(uint64);
+ shndx_pool_ = pindex_ + nslots_ * sizeof(uint32);
+ if (shndx_pool_ >= cu_index_ + cu_index_size_) {
+ version_ = 0;
+ }
+ } else if (version_ == 2) {
+ ncolumns_ = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(cu_index_) + sizeof(uint32));
+ nunits_ = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(cu_index_) + 2 * sizeof(uint32));
+ nslots_ = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(cu_index_) + 3 * sizeof(uint32));
+ phash_ = cu_index_ + 4 * sizeof(uint32);
+ pindex_ = phash_ + nslots_ * sizeof(uint64);
+ offset_table_ = pindex_ + nslots_ * sizeof(uint32);
+ size_table_ = offset_table_ + ncolumns_ * (nunits_ + 1) * sizeof(uint32);
+ abbrev_data_ = elf_reader_->GetSectionByName(".debug_abbrev.dwo",
+ &abbrev_size_);
+ info_data_ = elf_reader_->GetSectionByName(".debug_info.dwo", &info_size_);
+ str_offsets_data_ = elf_reader_->GetSectionByName(".debug_str_offsets.dwo",
+ &str_offsets_size_);
+ if (size_table_ >= cu_index_ + cu_index_size_) {
+ version_ = 0;
+ }
+ }
+}
+
+void DwpReader::ReadDebugSectionsForCU(uint64 dwo_id,
+ SectionMap* sections) {
+ if (version_ == 1) {
+ int slot = LookupCU(dwo_id);
+ if (slot == -1) {
+ return;
+ }
+
+ // The index table points to the section index pool, where we
+ // can read a list of section indexes for the debug sections
+ // for the CU whose dwo_id we are looking for.
+ int index = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(pindex_)
+ + slot * sizeof(uint32));
+ const char* shndx_list = shndx_pool_ + index * sizeof(uint32);
+ for (;;) {
+ if (shndx_list >= cu_index_ + cu_index_size_) {
+ version_ = 0;
+ return;
+ }
+ unsigned int shndx = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(shndx_list));
+ shndx_list += sizeof(uint32);
+ if (shndx == 0)
+ break;
+ const char* section_name = elf_reader_->GetSectionName(shndx);
+ size_t section_size;
+ const char* section_data;
+ // We're only interested in these four debug sections.
+ // The section names in the .dwo file end with ".dwo", but we
+ // add them to the sections table with their normal names.
+ if (!strncmp(section_name, ".debug_abbrev", strlen(".debug_abbrev"))) {
+ section_data = elf_reader_->GetSectionByIndex(shndx, &section_size);
+ sections->insert(std::make_pair(
+ ".debug_abbrev",
+ std::make_pair(reinterpret_cast<const uint8_t *> (section_data),
+ section_size)));
+ } else if (!strncmp(section_name, ".debug_info", strlen(".debug_info"))) {
+ section_data = elf_reader_->GetSectionByIndex(shndx, &section_size);
+ sections->insert(std::make_pair(
+ ".debug_info",
+ std::make_pair(reinterpret_cast<const uint8_t *> (section_data),
+ section_size)));
+ } else if (!strncmp(section_name, ".debug_str_offsets",
+ strlen(".debug_str_offsets"))) {
+ section_data = elf_reader_->GetSectionByIndex(shndx, &section_size);
+ sections->insert(std::make_pair(
+ ".debug_str_offsets",
+ std::make_pair(reinterpret_cast<const uint8_t *> (section_data),
+ section_size)));
+ }
+ }
+ sections->insert(std::make_pair(
+ ".debug_str",
+ std::make_pair(reinterpret_cast<const uint8_t *> (string_buffer_),
+ string_buffer_size_)));
+ } else if (version_ == 2) {
+ uint32 index = LookupCUv2(dwo_id);
+ if (index == 0) {
+ return;
+ }
+
+ // The index points to a row in each of the section offsets table
+ // and the section size table, where we can read the offsets and sizes
+ // of the contributions to each debug section from the CU whose dwo_id
+ // we are looking for. Row 0 of the section offsets table has the
+ // section ids for each column of the table. The size table begins
+ // with row 1.
+ const char* id_row = offset_table_;
+ const char* offset_row = offset_table_
+ + index * ncolumns_ * sizeof(uint32);
+ const char* size_row =
+ size_table_ + (index - 1) * ncolumns_ * sizeof(uint32);
+ if (size_row + ncolumns_ * sizeof(uint32) > cu_index_ + cu_index_size_) {
+ version_ = 0;
+ return;
+ }
+ for (unsigned int col = 0u; col < ncolumns_; ++col) {
+ uint32 section_id =
+ byte_reader_.ReadFourBytes(reinterpret_cast<const uint8_t *>(id_row)
+ + col * sizeof(uint32));
+ uint32 offset = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(offset_row)
+ + col * sizeof(uint32));
+ uint32 size = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(size_row) + col * sizeof(uint32));
+ if (section_id == DW_SECT_ABBREV) {
+ sections->insert(std::make_pair(
+ ".debug_abbrev",
+ std::make_pair(reinterpret_cast<const uint8_t *> (abbrev_data_)
+ + offset, size)));
+ } else if (section_id == DW_SECT_INFO) {
+ sections->insert(std::make_pair(
+ ".debug_info",
+ std::make_pair(reinterpret_cast<const uint8_t *> (info_data_)
+ + offset, size)));
+ } else if (section_id == DW_SECT_STR_OFFSETS) {
+ sections->insert(std::make_pair(
+ ".debug_str_offsets",
+ std::make_pair(reinterpret_cast<const uint8_t *> (str_offsets_data_)
+ + offset, size)));
+ }
+ }
+ sections->insert(std::make_pair(
+ ".debug_str",
+ std::make_pair(reinterpret_cast<const uint8_t *> (string_buffer_),
+ string_buffer_size_)));
+ }
+}
+
+int DwpReader::LookupCU(uint64 dwo_id) {
+ uint32 slot = static_cast<uint32>(dwo_id) & (nslots_ - 1);
+ uint64 probe = byte_reader_.ReadEightBytes(
+ reinterpret_cast<const uint8_t *>(phash_) + slot * sizeof(uint64));
+ if (probe != 0 && probe != dwo_id) {
+ uint32 secondary_hash =
+ (static_cast<uint32>(dwo_id >> 32) & (nslots_ - 1)) | 1;
+ do {
+ slot = (slot + secondary_hash) & (nslots_ - 1);
+ probe = byte_reader_.ReadEightBytes(
+ reinterpret_cast<const uint8_t *>(phash_) + slot * sizeof(uint64));
+ } while (probe != 0 && probe != dwo_id);
+ }
+ if (probe == 0)
+ return -1;
+ return slot;
+}
+
+uint32 DwpReader::LookupCUv2(uint64 dwo_id) {
+ uint32 slot = static_cast<uint32>(dwo_id) & (nslots_ - 1);
+ uint64 probe = byte_reader_.ReadEightBytes(
+ reinterpret_cast<const uint8_t *>(phash_) + slot * sizeof(uint64));
+ uint32 index = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(pindex_) + slot * sizeof(uint32));
+ if (index != 0 && probe != dwo_id) {
+ uint32 secondary_hash =
+ (static_cast<uint32>(dwo_id >> 32) & (nslots_ - 1)) | 1;
+ do {
+ slot = (slot + secondary_hash) & (nslots_ - 1);
+ probe = byte_reader_.ReadEightBytes(
+ reinterpret_cast<const uint8_t *>(phash_) + slot * sizeof(uint64));
+ index = byte_reader_.ReadFourBytes(
+ reinterpret_cast<const uint8_t *>(pindex_) + slot * sizeof(uint32));
+ } while (index != 0 && probe != dwo_id);
+ }
+ return index;
+}
+
+LineInfo::LineInfo(const uint8_t *buffer, uint64 buffer_length,
+ ByteReader* reader, LineInfoHandler* handler):
+ handler_(handler), reader_(reader), buffer_(buffer) {
+#ifndef NDEBUG
+ buffer_length_ = buffer_length;
+#endif
+ header_.std_opcode_lengths = NULL;
+}
+
+uint64 LineInfo::Start() {
+ ReadHeader();
+ ReadLines();
+ return after_header_ - buffer_;
+}
+
+// The header for a debug_line section is mildly complicated, because
+// the line info is very tightly encoded.
+void LineInfo::ReadHeader() {
+ const uint8_t *lineptr = buffer_;
+ size_t initial_length_size;
+
+ const uint64 initial_length
+ = reader_->ReadInitialLength(lineptr, &initial_length_size);
+
+ lineptr += initial_length_size;
+ header_.total_length = initial_length;
+ assert(buffer_ + initial_length_size + header_.total_length <=
+ buffer_ + buffer_length_);
+
+ // Address size *must* be set by CU ahead of time.
+ assert(reader_->AddressSize() != 0);
+
+ header_.version = reader_->ReadTwoBytes(lineptr);
+ lineptr += 2;
+
+ header_.prologue_length = reader_->ReadOffset(lineptr);
+ lineptr += reader_->OffsetSize();
+
+ header_.min_insn_length = reader_->ReadOneByte(lineptr);
+ lineptr += 1;
+
+ if (header_.version >= 4) {
+ __attribute__((unused)) uint8 max_ops_per_insn =
+ reader_->ReadOneByte(lineptr);
+ ++lineptr;
+ assert(max_ops_per_insn == 1);
+ }
+
+ header_.default_is_stmt = reader_->ReadOneByte(lineptr);
+ lineptr += 1;
+
+ header_.line_base = *reinterpret_cast<const int8*>(lineptr);
+ lineptr += 1;
+
+ header_.line_range = reader_->ReadOneByte(lineptr);
+ lineptr += 1;
+
+ header_.opcode_base = reader_->ReadOneByte(lineptr);
+ lineptr += 1;
+
+ header_.std_opcode_lengths = new std::vector<unsigned char>;
+ header_.std_opcode_lengths->resize(header_.opcode_base + 1);
+ (*header_.std_opcode_lengths)[0] = 0;
+ for (int i = 1; i < header_.opcode_base; i++) {
+ (*header_.std_opcode_lengths)[i] = reader_->ReadOneByte(lineptr);
+ lineptr += 1;
+ }
+
+ // It is legal for the directory entry table to be empty.
+ if (*lineptr) {
+ uint32 dirindex = 1;
+ while (*lineptr) {
+ const char *dirname = reinterpret_cast<const char *>(lineptr);
+ handler_->DefineDir(dirname, dirindex);
+ lineptr += strlen(dirname) + 1;
+ dirindex++;
+ }
+ }
+ lineptr++;
+
+ // It is also legal for the file entry table to be empty.
+ if (*lineptr) {
+ uint32 fileindex = 1;
+ size_t len;
+ while (*lineptr) {
+ const char *filename = reinterpret_cast<const char *>(lineptr);
+ lineptr += strlen(filename) + 1;
+
+ uint64 dirindex = reader_->ReadUnsignedLEB128(lineptr, &len);
+ lineptr += len;
+
+ uint64 mod_time = reader_->ReadUnsignedLEB128(lineptr, &len);
+ lineptr += len;
+
+ uint64 filelength = reader_->ReadUnsignedLEB128(lineptr, &len);
+ lineptr += len;
+ handler_->DefineFile(filename, fileindex, static_cast<uint32>(dirindex),
+ mod_time, filelength);
+ fileindex++;
+ }
+ }
+ lineptr++;
+
+ after_header_ = lineptr;
+}
+
+/* static */
+bool LineInfo::ProcessOneOpcode(ByteReader* reader,
+ LineInfoHandler* handler,
+ const struct LineInfoHeader &header,
+ const uint8_t *start,
+ struct LineStateMachine* lsm,
+ size_t* len,
+ uintptr pc,
+ bool *lsm_passes_pc) {
+ size_t oplen = 0;
+ size_t templen;
+ uint8 opcode = reader->ReadOneByte(start);
+ oplen++;
+ start++;
+
+ // If the opcode is great than the opcode_base, it is a special
+ // opcode. Most line programs consist mainly of special opcodes.
+ if (opcode >= header.opcode_base) {
+ opcode -= header.opcode_base;
+ const int64 advance_address = (opcode / header.line_range)
+ * header.min_insn_length;
+ const int32 advance_line = (opcode % header.line_range)
+ + header.line_base;
+
+ // Check if the lsm passes "pc". If so, mark it as passed.
+ if (lsm_passes_pc &&
+ lsm->address <= pc && pc < lsm->address + advance_address) {
+ *lsm_passes_pc = true;
+ }
+
+ lsm->address += advance_address;
+ lsm->line_num += advance_line;
+ lsm->basic_block = true;
+ *len = oplen;
+ return true;
+ }
+
+ // Otherwise, we have the regular opcodes
+ switch (opcode) {
+ case DW_LNS_copy: {
+ lsm->basic_block = false;
+ *len = oplen;
+ return true;
+ }
+
+ case DW_LNS_advance_pc: {
+ uint64 advance_address = reader->ReadUnsignedLEB128(start, &templen);
+ oplen += templen;
+
+ // Check if the lsm passes "pc". If so, mark it as passed.
+ if (lsm_passes_pc && lsm->address <= pc &&
+ pc < lsm->address + header.min_insn_length * advance_address) {
+ *lsm_passes_pc = true;
+ }
+
+ lsm->address += header.min_insn_length * advance_address;
+ }
+ break;
+ case DW_LNS_advance_line: {
+ const int64 advance_line = reader->ReadSignedLEB128(start, &templen);
+ oplen += templen;
+ lsm->line_num += static_cast<int32>(advance_line);
+
+ // With gcc 4.2.1, we can get the line_no here for the first time
+ // since DW_LNS_advance_line is called after DW_LNE_set_address is
+ // called. So we check if the lsm passes "pc" here, not in
+ // DW_LNE_set_address.
+ if (lsm_passes_pc && lsm->address == pc) {
+ *lsm_passes_pc = true;
+ }
+ }
+ break;
+ case DW_LNS_set_file: {
+ const uint64 fileno = reader->ReadUnsignedLEB128(start, &templen);
+ oplen += templen;
+ lsm->file_num = static_cast<uint32>(fileno);
+ }
+ break;
+ case DW_LNS_set_column: {
+ const uint64 colno = reader->ReadUnsignedLEB128(start, &templen);
+ oplen += templen;
+ lsm->column_num = static_cast<uint32>(colno);
+ }
+ break;
+ case DW_LNS_negate_stmt: {
+ lsm->is_stmt = !lsm->is_stmt;
+ }
+ break;
+ case DW_LNS_set_basic_block: {
+ lsm->basic_block = true;
+ }
+ break;
+ case DW_LNS_fixed_advance_pc: {
+ const uint16 advance_address = reader->ReadTwoBytes(start);
+ oplen += 2;
+
+ // Check if the lsm passes "pc". If so, mark it as passed.
+ if (lsm_passes_pc &&
+ lsm->address <= pc && pc < lsm->address + advance_address) {
+ *lsm_passes_pc = true;
+ }
+
+ lsm->address += advance_address;
+ }
+ break;
+ case DW_LNS_const_add_pc: {
+ const int64 advance_address = header.min_insn_length
+ * ((255 - header.opcode_base)
+ / header.line_range);
+
+ // Check if the lsm passes "pc". If so, mark it as passed.
+ if (lsm_passes_pc &&
+ lsm->address <= pc && pc < lsm->address + advance_address) {
+ *lsm_passes_pc = true;
+ }
+
+ lsm->address += advance_address;
+ }
+ break;
+ case DW_LNS_extended_op: {
+ const uint64 extended_op_len = reader->ReadUnsignedLEB128(start,
+ &templen);
+ start += templen;
+ oplen += templen + extended_op_len;
+
+ const uint64 extended_op = reader->ReadOneByte(start);
+ start++;
+
+ switch (extended_op) {
+ case DW_LNE_end_sequence: {
+ lsm->end_sequence = true;
+ *len = oplen;
+ return true;
+ }
+ break;
+ case DW_LNE_set_address: {
+ // With gcc 4.2.1, we cannot tell the line_no here since
+ // DW_LNE_set_address is called before DW_LNS_advance_line is
+ // called. So we do not check if the lsm passes "pc" here. See
+ // also the comment in DW_LNS_advance_line.
+ uint64 address = reader->ReadAddress(start);
+ lsm->address = address;
+ }
+ break;
+ case DW_LNE_define_file: {
+ const char *filename = reinterpret_cast<const char *>(start);
+
+ templen = strlen(filename) + 1;
+ start += templen;
+
+ uint64 dirindex = reader->ReadUnsignedLEB128(start, &templen);
+ oplen += templen;
+
+ const uint64 mod_time = reader->ReadUnsignedLEB128(start,
+ &templen);
+ oplen += templen;
+
+ const uint64 filelength = reader->ReadUnsignedLEB128(start,
+ &templen);
+ oplen += templen;
+
+ if (handler) {
+ handler->DefineFile(filename, -1, static_cast<uint32>(dirindex),
+ mod_time, filelength);
+ }
+ }
+ break;
+ }
+ }
+ break;
+
+ default: {
+ // Ignore unknown opcode silently
+ if (header.std_opcode_lengths) {
+ for (int i = 0; i < (*header.std_opcode_lengths)[opcode]; i++) {
+ reader->ReadUnsignedLEB128(start, &templen);
+ start += templen;
+ oplen += templen;
+ }
+ }
+ }
+ break;
+ }
+ *len = oplen;
+ return false;
+}
+
+void LineInfo::ReadLines() {
+ struct LineStateMachine lsm;
+
+ // lengthstart is the place the length field is based on.
+ // It is the point in the header after the initial length field
+ const uint8_t *lengthstart = buffer_;
+
+ // In 64 bit dwarf, the initial length is 12 bytes, because of the
+ // 0xffffffff at the start.
+ if (reader_->OffsetSize() == 8)
+ lengthstart += 12;
+ else
+ lengthstart += 4;
+
+ const uint8_t *lineptr = after_header_;
+ lsm.Reset(header_.default_is_stmt);
+
+ // The LineInfoHandler interface expects each line's length along
+ // with its address, but DWARF only provides addresses (sans
+ // length), and an end-of-sequence address; one infers the length
+ // from the next address. So we report a line only when we get the
+ // next line's address, or the end-of-sequence address.
+ bool have_pending_line = false;
+ uint64 pending_address = 0;
+ uint32 pending_file_num = 0, pending_line_num = 0, pending_column_num = 0;
+
+ while (lineptr < lengthstart + header_.total_length) {
+ size_t oplength;
+ bool add_row = ProcessOneOpcode(reader_, handler_, header_,
+ lineptr, &lsm, &oplength, (uintptr)-1,
+ NULL);
+ if (add_row) {
+ if (have_pending_line)
+ handler_->AddLine(pending_address, lsm.address - pending_address,
+ pending_file_num, pending_line_num,
+ pending_column_num);
+ if (lsm.end_sequence) {
+ lsm.Reset(header_.default_is_stmt);
+ have_pending_line = false;
+ } else {
+ pending_address = lsm.address;
+ pending_file_num = lsm.file_num;
+ pending_line_num = lsm.line_num;
+ pending_column_num = lsm.column_num;
+ have_pending_line = true;
+ }
+ }
+ lineptr += oplength;
+ }
+
+ after_header_ = lengthstart + header_.total_length;
+}
+
+RangeListReader::RangeListReader(const uint8_t *buffer, uint64 size,
+ ByteReader *reader, RangeListHandler *handler)
+ : buffer_(buffer), size_(size), reader_(reader), handler_(handler) { }
+
+bool RangeListReader::ReadRangeList(uint64 offset) {
+ const uint64 max_address =
+ (reader_->AddressSize() == 4) ? 0xffffffffUL
+ : 0xffffffffffffffffULL;
+ const uint64 entry_size = reader_->AddressSize() * 2;
+ bool list_end = false;
+
+ do {
+ if (offset > size_ - entry_size) {
+ return false; // Invalid range detected
+ }
+
+ uint64 start_address = reader_->ReadAddress(buffer_ + offset);
+ uint64 end_address =
+ reader_->ReadAddress(buffer_ + offset + reader_->AddressSize());
+
+ if (start_address == max_address) { // Base address selection
+ handler_->SetBaseAddress(end_address);
+ } else if (start_address == 0 && end_address == 0) { // End-of-list
+ handler_->Finish();
+ list_end = true;
+ } else { // Add a range entry
+ handler_->AddRange(start_address, end_address);
+ }
+
+ offset += entry_size;
+ } while (!list_end);
+
+ return true;
+}
+
+// A DWARF rule for recovering the address or value of a register, or
+// computing the canonical frame address. There is one subclass of this for
+// each '*Rule' member function in CallFrameInfo::Handler.
+//
+// It's annoying that we have to handle Rules using pointers (because
+// the concrete instances can have an arbitrary size). They're small,
+// so it would be much nicer if we could just handle them by value
+// instead of fretting about ownership and destruction.
+//
+// It seems like all these could simply be instances of std::tr1::bind,
+// except that we need instances to be EqualityComparable, too.
+//
+// This could logically be nested within State, but then the qualified names
+// get horrendous.
+class CallFrameInfo::Rule {
+ public:
+ virtual ~Rule() { }
+
+ // Tell HANDLER that, at ADDRESS in the program, REG can be recovered using
+ // this rule. If REG is kCFARegister, then this rule describes how to compute
+ // the canonical frame address. Return what the HANDLER member function
+ // returned.
+ virtual bool Handle(Handler *handler,
+ uint64 address, int reg) const = 0;
+
+ // Equality on rules. We use these to decide which rules we need
+ // to report after a DW_CFA_restore_state instruction.
+ virtual bool operator==(const Rule &rhs) const = 0;
+
+ bool operator!=(const Rule &rhs) const { return ! (*this == rhs); }
+
+ // Return a pointer to a copy of this rule.
+ virtual Rule *Copy() const = 0;
+
+ // If this is a base+offset rule, change its base register to REG.
+ // Otherwise, do nothing. (Ugly, but required for DW_CFA_def_cfa_register.)
+ virtual void SetBaseRegister(unsigned reg) { }
+
+ // If this is a base+offset rule, change its offset to OFFSET. Otherwise,
+ // do nothing. (Ugly, but required for DW_CFA_def_cfa_offset.)
+ virtual void SetOffset(long long offset) { }
+};
+
+// Rule: the value the register had in the caller cannot be recovered.
+class CallFrameInfo::UndefinedRule: public CallFrameInfo::Rule {
+ public:
+ UndefinedRule() { }
+ ~UndefinedRule() { }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->UndefinedRule(address, reg);
+ }
+ bool operator==(const Rule &rhs) const {
+ // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
+ // been carefully considered; cheap RTTI-like workarounds are forbidden.
+ const UndefinedRule *our_rhs = dynamic_cast<const UndefinedRule *>(&rhs);
+ return (our_rhs != NULL);
+ }
+ Rule *Copy() const { return new UndefinedRule(*this); }
+};
+
+// Rule: the register's value is the same as that it had in the caller.
+class CallFrameInfo::SameValueRule: public CallFrameInfo::Rule {
+ public:
+ SameValueRule() { }
+ ~SameValueRule() { }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->SameValueRule(address, reg);
+ }
+ bool operator==(const Rule &rhs) const {
+ // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
+ // been carefully considered; cheap RTTI-like workarounds are forbidden.
+ const SameValueRule *our_rhs = dynamic_cast<const SameValueRule *>(&rhs);
+ return (our_rhs != NULL);
+ }
+ Rule *Copy() const { return new SameValueRule(*this); }
+};
+
+// Rule: the register is saved at OFFSET from BASE_REGISTER. BASE_REGISTER
+// may be CallFrameInfo::Handler::kCFARegister.
+class CallFrameInfo::OffsetRule: public CallFrameInfo::Rule {
+ public:
+ OffsetRule(int base_register, long offset)
+ : base_register_(base_register), offset_(offset) { }
+ ~OffsetRule() { }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->OffsetRule(address, reg, base_register_, offset_);
+ }
+ bool operator==(const Rule &rhs) const {
+ // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
+ // been carefully considered; cheap RTTI-like workarounds are forbidden.
+ const OffsetRule *our_rhs = dynamic_cast<const OffsetRule *>(&rhs);
+ return (our_rhs &&
+ base_register_ == our_rhs->base_register_ &&
+ offset_ == our_rhs->offset_);
+ }
+ Rule *Copy() const { return new OffsetRule(*this); }
+ // We don't actually need SetBaseRegister or SetOffset here, since they
+ // are only ever applied to CFA rules, for DW_CFA_def_cfa_offset, and it
+ // doesn't make sense to use OffsetRule for computing the CFA: it
+ // computes the address at which a register is saved, not a value.
+ private:
+ int base_register_;
+ long offset_;
+};
+
+// Rule: the value the register had in the caller is the value of
+// BASE_REGISTER plus offset. BASE_REGISTER may be
+// CallFrameInfo::Handler::kCFARegister.
+class CallFrameInfo::ValOffsetRule: public CallFrameInfo::Rule {
+ public:
+ ValOffsetRule(int base_register, long offset)
+ : base_register_(base_register), offset_(offset) { }
+ ~ValOffsetRule() { }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->ValOffsetRule(address, reg, base_register_, offset_);
+ }
+ bool operator==(const Rule &rhs) const {
+ // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
+ // been carefully considered; cheap RTTI-like workarounds are forbidden.
+ const ValOffsetRule *our_rhs = dynamic_cast<const ValOffsetRule *>(&rhs);
+ return (our_rhs &&
+ base_register_ == our_rhs->base_register_ &&
+ offset_ == our_rhs->offset_);
+ }
+ Rule *Copy() const { return new ValOffsetRule(*this); }
+ void SetBaseRegister(unsigned reg) { base_register_ = reg; }
+ void SetOffset(long long offset) { offset_ = offset; }
+ private:
+ int base_register_;
+ long offset_;
+};
+
+// Rule: the register has been saved in another register REGISTER_NUMBER_.
+class CallFrameInfo::RegisterRule: public CallFrameInfo::Rule {
+ public:
+ explicit RegisterRule(int register_number)
+ : register_number_(register_number) { }
+ ~RegisterRule() { }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->RegisterRule(address, reg, register_number_);
+ }
+ bool operator==(const Rule &rhs) const {
+ // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
+ // been carefully considered; cheap RTTI-like workarounds are forbidden.
+ const RegisterRule *our_rhs = dynamic_cast<const RegisterRule *>(&rhs);
+ return (our_rhs && register_number_ == our_rhs->register_number_);
+ }
+ Rule *Copy() const { return new RegisterRule(*this); }
+ private:
+ int register_number_;
+};
+
+// Rule: EXPRESSION evaluates to the address at which the register is saved.
+class CallFrameInfo::ExpressionRule: public CallFrameInfo::Rule {
+ public:
+ explicit ExpressionRule(const string &expression)
+ : expression_(expression) { }
+ ~ExpressionRule() { }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->ExpressionRule(address, reg, expression_);
+ }
+ bool operator==(const Rule &rhs) const {
+ // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
+ // been carefully considered; cheap RTTI-like workarounds are forbidden.
+ const ExpressionRule *our_rhs = dynamic_cast<const ExpressionRule *>(&rhs);
+ return (our_rhs && expression_ == our_rhs->expression_);
+ }
+ Rule *Copy() const { return new ExpressionRule(*this); }
+ private:
+ string expression_;
+};
+
+// Rule: EXPRESSION evaluates to the address at which the register is saved.
+class CallFrameInfo::ValExpressionRule: public CallFrameInfo::Rule {
+ public:
+ explicit ValExpressionRule(const string &expression)
+ : expression_(expression) { }
+ ~ValExpressionRule() { }
+ bool Handle(Handler *handler, uint64 address, int reg) const {
+ return handler->ValExpressionRule(address, reg, expression_);
+ }
+ bool operator==(const Rule &rhs) const {
+ // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
+ // been carefully considered; cheap RTTI-like workarounds are forbidden.
+ const ValExpressionRule *our_rhs =
+ dynamic_cast<const ValExpressionRule *>(&rhs);
+ return (our_rhs && expression_ == our_rhs->expression_);
+ }
+ Rule *Copy() const { return new ValExpressionRule(*this); }
+ private:
+ string expression_;
+};
+
+// A map from register numbers to rules.
+class CallFrameInfo::RuleMap {
+ public:
+ RuleMap() : cfa_rule_(NULL) { }
+ RuleMap(const RuleMap &rhs) : cfa_rule_(NULL) { *this = rhs; }
+ ~RuleMap() { Clear(); }
+
+ RuleMap &operator=(const RuleMap &rhs);
+
+ // Set the rule for computing the CFA to RULE. Take ownership of RULE.
+ void SetCFARule(Rule *rule) { delete cfa_rule_; cfa_rule_ = rule; }
+
+ // Return the current CFA rule. Unlike RegisterRule, this RuleMap retains
+ // ownership of the rule. We use this for DW_CFA_def_cfa_offset and
+ // DW_CFA_def_cfa_register, and for detecting references to the CFA before
+ // a rule for it has been established.
+ Rule *CFARule() const { return cfa_rule_; }
+
+ // Return the rule for REG, or NULL if there is none. The caller takes
+ // ownership of the result.
+ Rule *RegisterRule(int reg) const;
+
+ // Set the rule for computing REG to RULE. Take ownership of RULE.
+ void SetRegisterRule(int reg, Rule *rule);
+
+ // Make all the appropriate calls to HANDLER as if we were changing from
+ // this RuleMap to NEW_RULES at ADDRESS. We use this to implement
+ // DW_CFA_restore_state, where lots of rules can change simultaneously.
+ // Return true if all handlers returned true; otherwise, return false.
+ bool HandleTransitionTo(Handler *handler, uint64 address,
+ const RuleMap &new_rules) const;
+
+ private:
+ // A map from register numbers to Rules.
+ typedef std::map<int, Rule *> RuleByNumber;
+
+ // Remove all register rules and clear cfa_rule_.
+ void Clear();
+
+ // The rule for computing the canonical frame address. This RuleMap owns
+ // this rule.
+ Rule *cfa_rule_;
+
+ // A map from register numbers to postfix expressions to recover
+ // their values. This RuleMap owns the Rules the map refers to.
+ RuleByNumber registers_;
+};
+
+CallFrameInfo::RuleMap &CallFrameInfo::RuleMap::operator=(const RuleMap &rhs) {
+ Clear();
+ // Since each map owns the rules it refers to, assignment must copy them.
+ if (rhs.cfa_rule_) cfa_rule_ = rhs.cfa_rule_->Copy();
+ for (RuleByNumber::const_iterator it = rhs.registers_.begin();
+ it != rhs.registers_.end(); it++)
+ registers_[it->first] = it->second->Copy();
+ return *this;
+}
+
+CallFrameInfo::Rule *CallFrameInfo::RuleMap::RegisterRule(int reg) const {
+ assert(reg != Handler::kCFARegister);
+ RuleByNumber::const_iterator it = registers_.find(reg);
+ if (it != registers_.end())
+ return it->second->Copy();
+ else
+ return NULL;
+}
+
+void CallFrameInfo::RuleMap::SetRegisterRule(int reg, Rule *rule) {
+ assert(reg != Handler::kCFARegister);
+ assert(rule);
+ Rule **slot = &registers_[reg];
+ delete *slot;
+ *slot = rule;
+}
+
+bool CallFrameInfo::RuleMap::HandleTransitionTo(
+ Handler *handler,
+ uint64 address,
+ const RuleMap &new_rules) const {
+ // Transition from cfa_rule_ to new_rules.cfa_rule_.
+ if (cfa_rule_ && new_rules.cfa_rule_) {
+ if (*cfa_rule_ != *new_rules.cfa_rule_ &&
+ !new_rules.cfa_rule_->Handle(handler, address,
+ Handler::kCFARegister))
+ return false;
+ } else if (cfa_rule_) {
+ // this RuleMap has a CFA rule but new_rules doesn't.
+ // CallFrameInfo::Handler has no way to handle this --- and shouldn't;
+ // it's garbage input. The instruction interpreter should have
+ // detected this and warned, so take no action here.
+ } else if (new_rules.cfa_rule_) {
+ // This shouldn't be possible: NEW_RULES is some prior state, and
+ // there's no way to remove entries.
+ assert(0);
+ } else {
+ // Both CFA rules are empty. No action needed.
+ }
+
+ // Traverse the two maps in order by register number, and report
+ // whatever differences we find.
+ RuleByNumber::const_iterator old_it = registers_.begin();
+ RuleByNumber::const_iterator new_it = new_rules.registers_.begin();
+ while (old_it != registers_.end() && new_it != new_rules.registers_.end()) {
+ if (old_it->first < new_it->first) {
+ // This RuleMap has an entry for old_it->first, but NEW_RULES
+ // doesn't.
+ //
+ // This isn't really the right thing to do, but since CFI generally
+ // only mentions callee-saves registers, and GCC's convention for
+ // callee-saves registers is that they are unchanged, it's a good
+ // approximation.
+ if (!handler->SameValueRule(address, old_it->first))
+ return false;
+ old_it++;
+ } else if (old_it->first > new_it->first) {
+ // NEW_RULES has entry for new_it->first, but this RuleMap
+ // doesn't. This shouldn't be possible: NEW_RULES is some prior
+ // state, and there's no way to remove entries.
+ assert(0);
+ } else {
+ // Both maps have an entry for this register. Report the new
+ // rule if it is different.
+ if (*old_it->second != *new_it->second &&
+ !new_it->second->Handle(handler, address, new_it->first))
+ return false;
+ new_it++, old_it++;
+ }
+ }
+ // Finish off entries from this RuleMap with no counterparts in new_rules.
+ while (old_it != registers_.end()) {
+ if (!handler->SameValueRule(address, old_it->first))
+ return false;
+ old_it++;
+ }
+ // Since we only make transitions from a rule set to some previously
+ // saved rule set, and we can only add rules to the map, NEW_RULES
+ // must have fewer rules than *this.
+ assert(new_it == new_rules.registers_.end());
+
+ return true;
+}
+
+// Remove all register rules and clear cfa_rule_.
+void CallFrameInfo::RuleMap::Clear() {
+ delete cfa_rule_;
+ cfa_rule_ = NULL;
+ for (RuleByNumber::iterator it = registers_.begin();
+ it != registers_.end(); it++)
+ delete it->second;
+ registers_.clear();
+}
+
+// The state of the call frame information interpreter as it processes
+// instructions from a CIE and FDE.
+class CallFrameInfo::State {
+ public:
+ // Create a call frame information interpreter state with the given
+ // reporter, reader, handler, and initial call frame info address.
+ State(ByteReader *reader, Handler *handler, Reporter *reporter,
+ uint64 address)
+ : reader_(reader), handler_(handler), reporter_(reporter),
+ address_(address), entry_(NULL), cursor_(NULL) { }
+
+ // Interpret instructions from CIE, save the resulting rule set for
+ // DW_CFA_restore instructions, and return true. On error, report
+ // the problem to reporter_ and return false.
+ bool InterpretCIE(const CIE &cie);
+
+ // Interpret instructions from FDE, and return true. On error,
+ // report the problem to reporter_ and return false.
+ bool InterpretFDE(const FDE &fde);
+
+ private:
+ // The operands of a CFI instruction, for ParseOperands.
+ struct Operands {
+ unsigned register_number; // A register number.
+ uint64 offset; // An offset or address.
+ long signed_offset; // A signed offset.
+ string expression; // A DWARF expression.
+ };
+
+ // Parse CFI instruction operands from STATE's instruction stream as
+ // described by FORMAT. On success, populate OPERANDS with the
+ // results, and return true. On failure, report the problem and
+ // return false.
+ //
+ // Each character of FORMAT should be one of the following:
+ //
+ // 'r' unsigned LEB128 register number (OPERANDS->register_number)
+ // 'o' unsigned LEB128 offset (OPERANDS->offset)
+ // 's' signed LEB128 offset (OPERANDS->signed_offset)
+ // 'a' machine-size address (OPERANDS->offset)
+ // (If the CIE has a 'z' augmentation string, 'a' uses the
+ // encoding specified by the 'R' argument.)
+ // '1' a one-byte offset (OPERANDS->offset)
+ // '2' a two-byte offset (OPERANDS->offset)
+ // '4' a four-byte offset (OPERANDS->offset)
+ // '8' an eight-byte offset (OPERANDS->offset)
+ // 'e' a DW_FORM_block holding a (OPERANDS->expression)
+ // DWARF expression
+ bool ParseOperands(const char *format, Operands *operands);
+
+ // Interpret one CFI instruction from STATE's instruction stream, update
+ // STATE, report any rule changes to handler_, and return true. On
+ // failure, report the problem and return false.
+ bool DoInstruction();
+
+ // The following Do* member functions are subroutines of DoInstruction,
+ // factoring out the actual work of operations that have several
+ // different encodings.
+
+ // Set the CFA rule to be the value of BASE_REGISTER plus OFFSET, and
+ // return true. On failure, report and return false. (Used for
+ // DW_CFA_def_cfa and DW_CFA_def_cfa_sf.)
+ bool DoDefCFA(unsigned base_register, long offset);
+
+ // Change the offset of the CFA rule to OFFSET, and return true. On
+ // failure, report and return false. (Subroutine for
+ // DW_CFA_def_cfa_offset and DW_CFA_def_cfa_offset_sf.)
+ bool DoDefCFAOffset(long offset);
+
+ // Specify that REG can be recovered using RULE, and return true. On
+ // failure, report and return false.
+ bool DoRule(unsigned reg, Rule *rule);
+
+ // Specify that REG can be found at OFFSET from the CFA, and return true.
+ // On failure, report and return false. (Subroutine for DW_CFA_offset,
+ // DW_CFA_offset_extended, and DW_CFA_offset_extended_sf.)
+ bool DoOffset(unsigned reg, long offset);
+
+ // Specify that the caller's value for REG is the CFA plus OFFSET,
+ // and return true. On failure, report and return false. (Subroutine
+ // for DW_CFA_val_offset and DW_CFA_val_offset_sf.)
+ bool DoValOffset(unsigned reg, long offset);
+
+ // Restore REG to the rule established in the CIE, and return true. On
+ // failure, report and return false. (Subroutine for DW_CFA_restore and
+ // DW_CFA_restore_extended.)
+ bool DoRestore(unsigned reg);
+
+ // Return the section offset of the instruction at cursor. For use
+ // in error messages.
+ uint64 CursorOffset() { return entry_->offset + (cursor_ - entry_->start); }
+
+ // Report that entry_ is incomplete, and return false. For brevity.
+ bool ReportIncomplete() {
+ reporter_->Incomplete(entry_->offset, entry_->kind);
+ return false;
+ }
+
+ // For reading multi-byte values with the appropriate endianness.
+ ByteReader *reader_;
+
+ // The handler to which we should report the data we find.
+ Handler *handler_;
+
+ // For reporting problems in the info we're parsing.
+ Reporter *reporter_;
+
+ // The code address to which the next instruction in the stream applies.
+ uint64 address_;
+
+ // The entry whose instructions we are currently processing. This is
+ // first a CIE, and then an FDE.
+ const Entry *entry_;
+
+ // The next instruction to process.
+ const uint8_t *cursor_;
+
+ // The current set of rules.
+ RuleMap rules_;
+
+ // The set of rules established by the CIE, used by DW_CFA_restore
+ // and DW_CFA_restore_extended. We set this after interpreting the
+ // CIE's instructions.
+ RuleMap cie_rules_;
+
+ // A stack of saved states, for DW_CFA_remember_state and
+ // DW_CFA_restore_state.
+ std::stack<RuleMap> saved_rules_;
+};
+
+bool CallFrameInfo::State::InterpretCIE(const CIE &cie) {
+ entry_ = &cie;
+ cursor_ = entry_->instructions;
+ while (cursor_ < entry_->end)
+ if (!DoInstruction())
+ return false;
+ // Note the rules established by the CIE, for use by DW_CFA_restore
+ // and DW_CFA_restore_extended.
+ cie_rules_ = rules_;
+ return true;
+}
+
+bool CallFrameInfo::State::InterpretFDE(const FDE &fde) {
+ entry_ = &fde;
+ cursor_ = entry_->instructions;
+ while (cursor_ < entry_->end)
+ if (!DoInstruction())
+ return false;
+ return true;
+}
+
+bool CallFrameInfo::State::ParseOperands(const char *format,
+ Operands *operands) {
+ size_t len;
+ const char *operand;
+
+ for (operand = format; *operand; operand++) {
+ size_t bytes_left = entry_->end - cursor_;
+ switch (*operand) {
+ case 'r':
+ operands->register_number = reader_->ReadUnsignedLEB128(cursor_, &len);
+ if (len > bytes_left) return ReportIncomplete();
+ cursor_ += len;
+ break;
+
+ case 'o':
+ operands->offset = reader_->ReadUnsignedLEB128(cursor_, &len);
+ if (len > bytes_left) return ReportIncomplete();
+ cursor_ += len;
+ break;
+
+ case 's':
+ operands->signed_offset = reader_->ReadSignedLEB128(cursor_, &len);
+ if (len > bytes_left) return ReportIncomplete();
+ cursor_ += len;
+ break;
+
+ case 'a':
+ operands->offset =
+ reader_->ReadEncodedPointer(cursor_, entry_->cie->pointer_encoding,
+ &len);
+ if (len > bytes_left) return ReportIncomplete();
+ cursor_ += len;
+ break;
+
+ case '1':
+ if (1 > bytes_left) return ReportIncomplete();
+ operands->offset = static_cast<unsigned char>(*cursor_++);
+ break;
+
+ case '2':
+ if (2 > bytes_left) return ReportIncomplete();
+ operands->offset = reader_->ReadTwoBytes(cursor_);
+ cursor_ += 2;
+ break;
+
+ case '4':
+ if (4 > bytes_left) return ReportIncomplete();
+ operands->offset = reader_->ReadFourBytes(cursor_);
+ cursor_ += 4;
+ break;
+
+ case '8':
+ if (8 > bytes_left) return ReportIncomplete();
+ operands->offset = reader_->ReadEightBytes(cursor_);
+ cursor_ += 8;
+ break;
+
+ case 'e': {
+ size_t expression_length = reader_->ReadUnsignedLEB128(cursor_, &len);
+ if (len > bytes_left || expression_length > bytes_left - len)
+ return ReportIncomplete();
+ cursor_ += len;
+ operands->expression = string(reinterpret_cast<const char *>(cursor_),
+ expression_length);
+ cursor_ += expression_length;
+ break;
+ }
+
+ default:
+ assert(0);
+ }
+ }
+
+ return true;
+}
+
+bool CallFrameInfo::State::DoInstruction() {
+ CIE *cie = entry_->cie;
+ Operands ops;
+
+ // Our entry's kind should have been set by now.
+ assert(entry_->kind != kUnknown);
+
+ // We shouldn't have been invoked unless there were more
+ // instructions to parse.
+ assert(cursor_ < entry_->end);
+
+ unsigned opcode = *cursor_++;
+ if ((opcode & 0xc0) != 0) {
+ switch (opcode & 0xc0) {
+ // Advance the address.
+ case DW_CFA_advance_loc: {
+ size_t code_offset = opcode & 0x3f;
+ address_ += code_offset * cie->code_alignment_factor;
+ break;
+ }
+
+ // Find a register at an offset from the CFA.
+ case DW_CFA_offset:
+ if (!ParseOperands("o", &ops) ||
+ !DoOffset(opcode & 0x3f, ops.offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // Restore the rule established for a register by the CIE.
+ case DW_CFA_restore:
+ if (!DoRestore(opcode & 0x3f)) return false;
+ break;
+
+ // The 'if' above should have excluded this possibility.
+ default:
+ assert(0);
+ }
+
+ // Return here, so the big switch below won't be indented.
+ return true;
+ }
+
+ switch (opcode) {
+ // Set the address.
+ case DW_CFA_set_loc:
+ if (!ParseOperands("a", &ops)) return false;
+ address_ = ops.offset;
+ break;
+
+ // Advance the address.
+ case DW_CFA_advance_loc1:
+ if (!ParseOperands("1", &ops)) return false;
+ address_ += ops.offset * cie->code_alignment_factor;
+ break;
+
+ // Advance the address.
+ case DW_CFA_advance_loc2:
+ if (!ParseOperands("2", &ops)) return false;
+ address_ += ops.offset * cie->code_alignment_factor;
+ break;
+
+ // Advance the address.
+ case DW_CFA_advance_loc4:
+ if (!ParseOperands("4", &ops)) return false;
+ address_ += ops.offset * cie->code_alignment_factor;
+ break;
+
+ // Advance the address.
+ case DW_CFA_MIPS_advance_loc8:
+ if (!ParseOperands("8", &ops)) return false;
+ address_ += ops.offset * cie->code_alignment_factor;
+ break;
+
+ // Compute the CFA by adding an offset to a register.
+ case DW_CFA_def_cfa:
+ if (!ParseOperands("ro", &ops) ||
+ !DoDefCFA(ops.register_number, ops.offset))
+ return false;
+ break;
+
+ // Compute the CFA by adding an offset to a register.
+ case DW_CFA_def_cfa_sf:
+ if (!ParseOperands("rs", &ops) ||
+ !DoDefCFA(ops.register_number,
+ ops.signed_offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // Change the base register used to compute the CFA.
+ case DW_CFA_def_cfa_register: {
+ if (!ParseOperands("r", &ops)) return false;
+ Rule *cfa_rule = rules_.CFARule();
+ if (!cfa_rule) {
+ if (!DoDefCFA(ops.register_number, ops.offset)) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ } else {
+ cfa_rule->SetBaseRegister(ops.register_number);
+ if (!cfa_rule->Handle(handler_, address_,
+ Handler::kCFARegister))
+ return false;
+ }
+ break;
+ }
+
+ // Change the offset used to compute the CFA.
+ case DW_CFA_def_cfa_offset:
+ if (!ParseOperands("o", &ops) ||
+ !DoDefCFAOffset(ops.offset))
+ return false;
+ break;
+
+ // Change the offset used to compute the CFA.
+ case DW_CFA_def_cfa_offset_sf:
+ if (!ParseOperands("s", &ops) ||
+ !DoDefCFAOffset(ops.signed_offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // Specify an expression whose value is the CFA.
+ case DW_CFA_def_cfa_expression: {
+ if (!ParseOperands("e", &ops))
+ return false;
+ Rule *rule = new ValExpressionRule(ops.expression);
+ rules_.SetCFARule(rule);
+ if (!rule->Handle(handler_, address_,
+ Handler::kCFARegister))
+ return false;
+ break;
+ }
+
+ // The register's value cannot be recovered.
+ case DW_CFA_undefined: {
+ if (!ParseOperands("r", &ops) ||
+ !DoRule(ops.register_number, new UndefinedRule()))
+ return false;
+ break;
+ }
+
+ // The register's value is unchanged from its value in the caller.
+ case DW_CFA_same_value: {
+ if (!ParseOperands("r", &ops) ||
+ !DoRule(ops.register_number, new SameValueRule()))
+ return false;
+ break;
+ }
+
+ // Find a register at an offset from the CFA.
+ case DW_CFA_offset_extended:
+ if (!ParseOperands("ro", &ops) ||
+ !DoOffset(ops.register_number,
+ ops.offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register is saved at an offset from the CFA.
+ case DW_CFA_offset_extended_sf:
+ if (!ParseOperands("rs", &ops) ||
+ !DoOffset(ops.register_number,
+ ops.signed_offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register is saved at an offset from the CFA.
+ case DW_CFA_GNU_negative_offset_extended:
+ if (!ParseOperands("ro", &ops) ||
+ !DoOffset(ops.register_number,
+ -ops.offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register's value is the sum of the CFA plus an offset.
+ case DW_CFA_val_offset:
+ if (!ParseOperands("ro", &ops) ||
+ !DoValOffset(ops.register_number,
+ ops.offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register's value is the sum of the CFA plus an offset.
+ case DW_CFA_val_offset_sf:
+ if (!ParseOperands("rs", &ops) ||
+ !DoValOffset(ops.register_number,
+ ops.signed_offset * cie->data_alignment_factor))
+ return false;
+ break;
+
+ // The register has been saved in another register.
+ case DW_CFA_register: {
+ if (!ParseOperands("ro", &ops) ||
+ !DoRule(ops.register_number, new RegisterRule(ops.offset)))
+ return false;
+ break;
+ }
+
+ // An expression yields the address at which the register is saved.
+ case DW_CFA_expression: {
+ if (!ParseOperands("re", &ops) ||
+ !DoRule(ops.register_number, new ExpressionRule(ops.expression)))
+ return false;
+ break;
+ }
+
+ // An expression yields the caller's value for the register.
+ case DW_CFA_val_expression: {
+ if (!ParseOperands("re", &ops) ||
+ !DoRule(ops.register_number, new ValExpressionRule(ops.expression)))
+ return false;
+ break;
+ }
+
+ // Restore the rule established for a register by the CIE.
+ case DW_CFA_restore_extended:
+ if (!ParseOperands("r", &ops) ||
+ !DoRestore( ops.register_number))
+ return false;
+ break;
+
+ // Save the current set of rules on a stack.
+ case DW_CFA_remember_state:
+ saved_rules_.push(rules_);
+ break;
+
+ // Pop the current set of rules off the stack.
+ case DW_CFA_restore_state: {
+ if (saved_rules_.empty()) {
+ reporter_->EmptyStateStack(entry_->offset, entry_->kind,
+ CursorOffset());
+ return false;
+ }
+ const RuleMap &new_rules = saved_rules_.top();
+ if (rules_.CFARule() && !new_rules.CFARule()) {
+ reporter_->ClearingCFARule(entry_->offset, entry_->kind,
+ CursorOffset());
+ return false;
+ }
+ rules_.HandleTransitionTo(handler_, address_, new_rules);
+ rules_ = new_rules;
+ saved_rules_.pop();
+ break;
+ }
+
+ // No operation. (Padding instruction.)
+ case DW_CFA_nop:
+ break;
+
+ // A SPARC register window save: Registers 8 through 15 (%o0-%o7)
+ // are saved in registers 24 through 31 (%i0-%i7), and registers
+ // 16 through 31 (%l0-%l7 and %i0-%i7) are saved at CFA offsets
+ // (0-15 * the register size). The register numbers must be
+ // hard-coded. A GNU extension, and not a pretty one.
+ case DW_CFA_GNU_window_save: {
+ // Save %o0-%o7 in %i0-%i7.
+ for (int i = 8; i < 16; i++)
+ if (!DoRule(i, new RegisterRule(i + 16)))
+ return false;
+ // Save %l0-%l7 and %i0-%i7 at the CFA.
+ for (int i = 16; i < 32; i++)
+ // Assume that the byte reader's address size is the same as
+ // the architecture's register size. !@#%*^ hilarious.
+ if (!DoRule(i, new OffsetRule(Handler::kCFARegister,
+ (i - 16) * reader_->AddressSize())))
+ return false;
+ break;
+ }
+
+ // I'm not sure what this is. GDB doesn't use it for unwinding.
+ case DW_CFA_GNU_args_size:
+ if (!ParseOperands("o", &ops)) return false;
+ break;
+
+ // An opcode we don't recognize.
+ default: {
+ reporter_->BadInstruction(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ }
+
+ return true;
+}
+
+bool CallFrameInfo::State::DoDefCFA(unsigned base_register, long offset) {
+ Rule *rule = new ValOffsetRule(base_register, offset);
+ rules_.SetCFARule(rule);
+ return rule->Handle(handler_, address_,
+ Handler::kCFARegister);
+}
+
+bool CallFrameInfo::State::DoDefCFAOffset(long offset) {
+ Rule *cfa_rule = rules_.CFARule();
+ if (!cfa_rule) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ cfa_rule->SetOffset(offset);
+ return cfa_rule->Handle(handler_, address_,
+ Handler::kCFARegister);
+}
+
+bool CallFrameInfo::State::DoRule(unsigned reg, Rule *rule) {
+ rules_.SetRegisterRule(reg, rule);
+ return rule->Handle(handler_, address_, reg);
+}
+
+bool CallFrameInfo::State::DoOffset(unsigned reg, long offset) {
+ if (!rules_.CFARule()) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ return DoRule(reg,
+ new OffsetRule(Handler::kCFARegister, offset));
+}
+
+bool CallFrameInfo::State::DoValOffset(unsigned reg, long offset) {
+ if (!rules_.CFARule()) {
+ reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
+ return false;
+ }
+ return DoRule(reg,
+ new ValOffsetRule(Handler::kCFARegister, offset));
+}
+
+bool CallFrameInfo::State::DoRestore(unsigned reg) {
+ // DW_CFA_restore and DW_CFA_restore_extended don't make sense in a CIE.
+ if (entry_->kind == kCIE) {
+ reporter_->RestoreInCIE(entry_->offset, CursorOffset());
+ return false;
+ }
+ Rule *rule = cie_rules_.RegisterRule(reg);
+ if (!rule) {
+ // This isn't really the right thing to do, but since CFI generally
+ // only mentions callee-saves registers, and GCC's convention for
+ // callee-saves registers is that they are unchanged, it's a good
+ // approximation.
+ rule = new SameValueRule();
+ }
+ return DoRule(reg, rule);
+}
+
+bool CallFrameInfo::ReadEntryPrologue(const uint8_t *cursor, Entry *entry) {
+ const uint8_t *buffer_end = buffer_ + buffer_length_;
+
+ // Initialize enough of ENTRY for use in error reporting.
+ entry->offset = cursor - buffer_;
+ entry->start = cursor;
+ entry->kind = kUnknown;
+ entry->end = NULL;
+
+ // Read the initial length. This sets reader_'s offset size.
+ size_t length_size;
+ uint64 length = reader_->ReadInitialLength(cursor, &length_size);
+ if (length_size > size_t(buffer_end - cursor))
+ return ReportIncomplete(entry);
+ cursor += length_size;
+
+ // In a .eh_frame section, a length of zero marks the end of the series
+ // of entries.
+ if (length == 0 && eh_frame_) {
+ entry->kind = kTerminator;
+ entry->end = cursor;
+ return true;
+ }
+
+ // Validate the length.
+ if (length > size_t(buffer_end - cursor))
+ return ReportIncomplete(entry);
+
+ // The length is the number of bytes after the initial length field;
+ // we have that position handy at this point, so compute the end
+ // now. (If we're parsing 64-bit-offset DWARF on a 32-bit machine,
+ // and the length didn't fit in a size_t, we would have rejected it
+ // above.)
+ entry->end = cursor + length;
+
+ // Parse the next field: either the offset of a CIE or a CIE id.
+ size_t offset_size = reader_->OffsetSize();
+ if (offset_size > size_t(entry->end - cursor)) return ReportIncomplete(entry);
+ entry->id = reader_->ReadOffset(cursor);
+
+ // Don't advance cursor past id field yet; in .eh_frame data we need
+ // the id's position to compute the section offset of an FDE's CIE.
+
+ // Now we can decide what kind of entry this is.
+ if (eh_frame_) {
+ // In .eh_frame data, an ID of zero marks the entry as a CIE, and
+ // anything else is an offset from the id field of the FDE to the start
+ // of the CIE.
+ if (entry->id == 0) {
+ entry->kind = kCIE;
+ } else {
+ entry->kind = kFDE;
+ // Turn the offset from the id into an offset from the buffer's start.
+ entry->id = (cursor - buffer_) - entry->id;
+ }
+ } else {
+ // In DWARF CFI data, an ID of ~0 (of the appropriate width, given the
+ // offset size for the entry) marks the entry as a CIE, and anything
+ // else is the offset of the CIE from the beginning of the section.
+ if (offset_size == 4)
+ entry->kind = (entry->id == 0xffffffff) ? kCIE : kFDE;
+ else {
+ assert(offset_size == 8);
+ entry->kind = (entry->id == 0xffffffffffffffffULL) ? kCIE : kFDE;
+ }
+ }
+
+ // Now advance cursor past the id.
+ cursor += offset_size;
+
+ // The fields specific to this kind of entry start here.
+ entry->fields = cursor;
+
+ entry->cie = NULL;
+
+ return true;
+}
+
+bool CallFrameInfo::ReadCIEFields(CIE *cie) {
+ const uint8_t *cursor = cie->fields;
+ size_t len;
+
+ assert(cie->kind == kCIE);
+
+ // Prepare for early exit.
+ cie->version = 0;
+ cie->augmentation.clear();
+ cie->code_alignment_factor = 0;
+ cie->data_alignment_factor = 0;
+ cie->return_address_register = 0;
+ cie->has_z_augmentation = false;
+ cie->pointer_encoding = DW_EH_PE_absptr;
+ cie->instructions = 0;
+
+ // Parse the version number.
+ if (cie->end - cursor < 1)
+ return ReportIncomplete(cie);
+ cie->version = reader_->ReadOneByte(cursor);
+ cursor++;
+
+ // If we don't recognize the version, we can't parse any more fields of the
+ // CIE. For DWARF CFI, we handle versions 1 through 4 (there was never a
+ // version 2 of CFI data). For .eh_frame, we handle versions 1 and 4 as well;
+ // the difference between those versions seems to be the same as for
+ // .debug_frame.
+ if (cie->version < 1 || cie->version > 4) {
+ reporter_->UnrecognizedVersion(cie->offset, cie->version);
+ return false;
+ }
+
+ const uint8_t *augmentation_start = cursor;
+ const uint8_t *augmentation_end =
+ reinterpret_cast<const uint8_t *>(memchr(augmentation_start, '\0',
+ cie->end - augmentation_start));
+ if (! augmentation_end) return ReportIncomplete(cie);
+ cursor = augmentation_end;
+ cie->augmentation = string(reinterpret_cast<const char *>(augmentation_start),
+ cursor - augmentation_start);
+ // Skip the terminating '\0'.
+ cursor++;
+
+ // Is this CFI augmented?
+ if (!cie->augmentation.empty()) {
+ // Is it an augmentation we recognize?
+ if (cie->augmentation[0] == DW_Z_augmentation_start) {
+ // Linux C++ ABI 'z' augmentation, used for exception handling data.
+ cie->has_z_augmentation = true;
+ } else {
+ // Not an augmentation we recognize. Augmentations can have arbitrary
+ // effects on the form of rest of the content, so we have to give up.
+ reporter_->UnrecognizedAugmentation(cie->offset, cie->augmentation);
+ return false;
+ }
+ }
+
+ if (cie->version >= 4) {
+ cie->address_size = *cursor++;
+ if (cie->address_size != 8 && cie->address_size != 4) {
+ reporter_->UnexpectedAddressSize(cie->offset, cie->address_size);
+ return false;
+ }
+
+ cie->segment_size = *cursor++;
+ if (cie->segment_size != 0) {
+ reporter_->UnexpectedSegmentSize(cie->offset, cie->segment_size);
+ return false;
+ }
+ }
+
+ // Parse the code alignment factor.
+ cie->code_alignment_factor = reader_->ReadUnsignedLEB128(cursor, &len);
+ if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
+ cursor += len;
+
+ // Parse the data alignment factor.
+ cie->data_alignment_factor = reader_->ReadSignedLEB128(cursor, &len);
+ if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
+ cursor += len;
+
+ // Parse the return address register. This is a ubyte in version 1, and
+ // a ULEB128 in version 3.
+ if (cie->version == 1) {
+ if (cursor >= cie->end) return ReportIncomplete(cie);
+ cie->return_address_register = uint8(*cursor++);
+ } else {
+ cie->return_address_register = reader_->ReadUnsignedLEB128(cursor, &len);
+ if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
+ cursor += len;
+ }
+
+ // If we have a 'z' augmentation string, find the augmentation data and
+ // use the augmentation string to parse it.
+ if (cie->has_z_augmentation) {
+ uint64_t data_size = reader_->ReadUnsignedLEB128(cursor, &len);
+ if (size_t(cie->end - cursor) < len + data_size)
+ return ReportIncomplete(cie);
+ cursor += len;
+ const uint8_t *data = cursor;
+ cursor += data_size;
+ const uint8_t *data_end = cursor;
+
+ cie->has_z_lsda = false;
+ cie->has_z_personality = false;
+ cie->has_z_signal_frame = false;
+
+ // Walk the augmentation string, and extract values from the
+ // augmentation data as the string directs.
+ for (size_t i = 1; i < cie->augmentation.size(); i++) {
+ switch (cie->augmentation[i]) {
+ case DW_Z_has_LSDA:
+ // The CIE's augmentation data holds the language-specific data
+ // area pointer's encoding, and the FDE's augmentation data holds
+ // the pointer itself.
+ cie->has_z_lsda = true;
+ // Fetch the LSDA encoding from the augmentation data.
+ if (data >= data_end) return ReportIncomplete(cie);
+ cie->lsda_encoding = DwarfPointerEncoding(*data++);
+ if (!reader_->ValidEncoding(cie->lsda_encoding)) {
+ reporter_->InvalidPointerEncoding(cie->offset, cie->lsda_encoding);
+ return false;
+ }
+ // Don't check if the encoding is usable here --- we haven't
+ // read the FDE's fields yet, so we're not prepared for
+ // DW_EH_PE_funcrel, although that's a fine encoding for the
+ // LSDA to use, since it appears in the FDE.
+ break;
+
+ case DW_Z_has_personality_routine:
+ // The CIE's augmentation data holds the personality routine
+ // pointer's encoding, followed by the pointer itself.
+ cie->has_z_personality = true;
+ // Fetch the personality routine pointer's encoding from the
+ // augmentation data.
+ if (data >= data_end) return ReportIncomplete(cie);
+ cie->personality_encoding = DwarfPointerEncoding(*data++);
+ if (!reader_->ValidEncoding(cie->personality_encoding)) {
+ reporter_->InvalidPointerEncoding(cie->offset,
+ cie->personality_encoding);
+ return false;
+ }
+ if (!reader_->UsableEncoding(cie->personality_encoding)) {
+ reporter_->UnusablePointerEncoding(cie->offset,
+ cie->personality_encoding);
+ return false;
+ }
+ // Fetch the personality routine's pointer itself from the data.
+ cie->personality_address =
+ reader_->ReadEncodedPointer(data, cie->personality_encoding,
+ &len);
+ if (len > size_t(data_end - data))
+ return ReportIncomplete(cie);
+ data += len;
+ break;
+
+ case DW_Z_has_FDE_address_encoding:
+ // The CIE's augmentation data holds the pointer encoding to use
+ // for addresses in the FDE.
+ if (data >= data_end) return ReportIncomplete(cie);
+ cie->pointer_encoding = DwarfPointerEncoding(*data++);
+ if (!reader_->ValidEncoding(cie->pointer_encoding)) {
+ reporter_->InvalidPointerEncoding(cie->offset,
+ cie->pointer_encoding);
+ return false;
+ }
+ if (!reader_->UsableEncoding(cie->pointer_encoding)) {
+ reporter_->UnusablePointerEncoding(cie->offset,
+ cie->pointer_encoding);
+ return false;
+ }
+ break;
+
+ case DW_Z_is_signal_trampoline:
+ // Frames using this CIE are signal delivery frames.
+ cie->has_z_signal_frame = true;
+ break;
+
+ default:
+ // An augmentation we don't recognize.
+ reporter_->UnrecognizedAugmentation(cie->offset, cie->augmentation);
+ return false;
+ }
+ }
+ }
+
+ // The CIE's instructions start here.
+ cie->instructions = cursor;
+
+ return true;
+}
+
+bool CallFrameInfo::ReadFDEFields(FDE *fde) {
+ const uint8_t *cursor = fde->fields;
+ size_t size;
+
+ fde->address = reader_->ReadEncodedPointer(cursor, fde->cie->pointer_encoding,
+ &size);
+ if (size > size_t(fde->end - cursor))
+ return ReportIncomplete(fde);
+ cursor += size;
+ reader_->SetFunctionBase(fde->address);
+
+ // For the length, we strip off the upper nybble of the encoding used for
+ // the starting address.
+ DwarfPointerEncoding length_encoding =
+ DwarfPointerEncoding(fde->cie->pointer_encoding & 0x0f);
+ fde->size = reader_->ReadEncodedPointer(cursor, length_encoding, &size);
+ if (size > size_t(fde->end - cursor))
+ return ReportIncomplete(fde);
+ cursor += size;
+
+ // If the CIE has a 'z' augmentation string, then augmentation data
+ // appears here.
+ if (fde->cie->has_z_augmentation) {
+ uint64_t data_size = reader_->ReadUnsignedLEB128(cursor, &size);
+ if (size_t(fde->end - cursor) < size + data_size)
+ return ReportIncomplete(fde);
+ cursor += size;
+
+ // In the abstract, we should walk the augmentation string, and extract
+ // items from the FDE's augmentation data as we encounter augmentation
+ // string characters that specify their presence: the ordering of items
+ // in the augmentation string determines the arrangement of values in
+ // the augmentation data.
+ //
+ // In practice, there's only ever one value in FDE augmentation data
+ // that we support --- the LSDA pointer --- and we have to bail if we
+ // see any unrecognized augmentation string characters. So if there is
+ // anything here at all, we know what it is, and where it starts.
+ if (fde->cie->has_z_lsda) {
+ // Check whether the LSDA's pointer encoding is usable now: only once
+ // we've parsed the FDE's starting address do we call reader_->
+ // SetFunctionBase, so that the DW_EH_PE_funcrel encoding becomes
+ // usable.
+ if (!reader_->UsableEncoding(fde->cie->lsda_encoding)) {
+ reporter_->UnusablePointerEncoding(fde->cie->offset,
+ fde->cie->lsda_encoding);
+ return false;
+ }
+
+ fde->lsda_address =
+ reader_->ReadEncodedPointer(cursor, fde->cie->lsda_encoding, &size);
+ if (size > data_size)
+ return ReportIncomplete(fde);
+ // Ideally, we would also complain here if there were unconsumed
+ // augmentation data.
+ }
+
+ cursor += data_size;
+ }
+
+ // The FDE's instructions start after those.
+ fde->instructions = cursor;
+
+ return true;
+}
+
+bool CallFrameInfo::Start() {
+ const uint8_t *buffer_end = buffer_ + buffer_length_;
+ const uint8_t *cursor;
+ bool all_ok = true;
+ const uint8_t *entry_end;
+ bool ok;
+
+ // Traverse all the entries in buffer_, skipping CIEs and offering
+ // FDEs to the handler.
+ for (cursor = buffer_; cursor < buffer_end;
+ cursor = entry_end, all_ok = all_ok && ok) {
+ FDE fde;
+
+ // Make it easy to skip this entry with 'continue': assume that
+ // things are not okay until we've checked all the data, and
+ // prepare the address of the next entry.
+ ok = false;
+
+ // Read the entry's prologue.
+ if (!ReadEntryPrologue(cursor, &fde)) {
+ if (!fde.end) {
+ // If we couldn't even figure out this entry's extent, then we
+ // must stop processing entries altogether.
+ all_ok = false;
+ break;
+ }
+ entry_end = fde.end;
+ continue;
+ }
+
+ // The next iteration picks up after this entry.
+ entry_end = fde.end;
+
+ // Did we see an .eh_frame terminating mark?
+ if (fde.kind == kTerminator) {
+ // If there appears to be more data left in the section after the
+ // terminating mark, warn the user. But this is just a warning;
+ // we leave all_ok true.
+ if (fde.end < buffer_end) reporter_->EarlyEHTerminator(fde.offset);
+ break;
+ }
+
+ // In this loop, we skip CIEs. We only parse them fully when we
+ // parse an FDE that refers to them. This limits our memory
+ // consumption (beyond the buffer itself) to that needed to
+ // process the largest single entry.
+ if (fde.kind != kFDE) {
+ ok = true;
+ continue;
+ }
+
+ // Validate the CIE pointer.
+ if (fde.id > buffer_length_) {
+ reporter_->CIEPointerOutOfRange(fde.offset, fde.id);
+ continue;
+ }
+
+ CIE cie;
+
+ // Parse this FDE's CIE header.
+ if (!ReadEntryPrologue(buffer_ + fde.id, &cie))
+ continue;
+ // This had better be an actual CIE.
+ if (cie.kind != kCIE) {
+ reporter_->BadCIEId(fde.offset, fde.id);
+ continue;
+ }
+ if (!ReadCIEFields(&cie))
+ continue;
+
+ // TODO(nbilling): This could lead to strange behavior if a single buffer
+ // contained a mixture of DWARF versions as well as address sizes. Not
+ // sure if it's worth handling such a case.
+
+ // DWARF4 CIE specifies address_size, so use it for this call frame.
+ if (cie.version >= 4) {
+ reader_->SetAddressSize(cie.address_size);
+ }
+
+ // We now have the values that govern both the CIE and the FDE.
+ cie.cie = &cie;
+ fde.cie = &cie;
+
+ // Parse the FDE's header.
+ if (!ReadFDEFields(&fde))
+ continue;
+
+ // Call Entry to ask the consumer if they're interested.
+ if (!handler_->Entry(fde.offset, fde.address, fde.size,
+ cie.version, cie.augmentation,
+ cie.return_address_register)) {
+ // The handler isn't interested in this entry. That's not an error.
+ ok = true;
+ continue;
+ }
+
+ if (cie.has_z_augmentation) {
+ // Report the personality routine address, if we have one.
+ if (cie.has_z_personality) {
+ if (!handler_
+ ->PersonalityRoutine(cie.personality_address,
+ IsIndirectEncoding(cie.personality_encoding)))
+ continue;
+ }
+
+ // Report the language-specific data area address, if we have one.
+ if (cie.has_z_lsda) {
+ if (!handler_
+ ->LanguageSpecificDataArea(fde.lsda_address,
+ IsIndirectEncoding(cie.lsda_encoding)))
+ continue;
+ }
+
+ // If this is a signal-handling frame, report that.
+ if (cie.has_z_signal_frame) {
+ if (!handler_->SignalHandler())
+ continue;
+ }
+ }
+
+ // Interpret the CIE's instructions, and then the FDE's instructions.
+ State state(reader_, handler_, reporter_, fde.address);
+ ok = state.InterpretCIE(cie) && state.InterpretFDE(fde);
+
+ // Tell the ByteReader that the function start address from the
+ // FDE header is no longer valid.
+ reader_->ClearFunctionBase();
+
+ // Report the end of the entry.
+ handler_->End();
+ }
+
+ return all_ok;
+}
+
+const char *CallFrameInfo::KindName(EntryKind kind) {
+ if (kind == CallFrameInfo::kUnknown)
+ return "entry";
+ else if (kind == CallFrameInfo::kCIE)
+ return "common information entry";
+ else if (kind == CallFrameInfo::kFDE)
+ return "frame description entry";
+ else {
+ assert (kind == CallFrameInfo::kTerminator);
+ return ".eh_frame sequence terminator";
+ }
+}
+
+bool CallFrameInfo::ReportIncomplete(Entry *entry) {
+ reporter_->Incomplete(entry->offset, entry->kind);
+ return false;
+}
+
+void CallFrameInfo::Reporter::Incomplete(uint64 offset,
+ CallFrameInfo::EntryKind kind) {
+ fprintf(stderr,
+ "%s: CFI %s at offset 0x%llx in '%s': entry ends early\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind), offset,
+ section_.c_str());
+}
+
+void CallFrameInfo::Reporter::EarlyEHTerminator(uint64 offset) {
+ fprintf(stderr,
+ "%s: CFI at offset 0x%llx in '%s': saw end-of-data marker"
+ " before end of section contents\n",
+ filename_.c_str(), offset, section_.c_str());
+}
+
+void CallFrameInfo::Reporter::CIEPointerOutOfRange(uint64 offset,
+ uint64 cie_offset) {
+ fprintf(stderr,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE pointer is out of range: 0x%llx\n",
+ filename_.c_str(), offset, section_.c_str(), cie_offset);
+}
+
+void CallFrameInfo::Reporter::BadCIEId(uint64 offset, uint64 cie_offset) {
+ fprintf(stderr,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE pointer does not point to a CIE: 0x%llx\n",
+ filename_.c_str(), offset, section_.c_str(), cie_offset);
+}
+
+void CallFrameInfo::Reporter::UnexpectedAddressSize(uint64 offset,
+ uint8_t address_size) {
+ fprintf(stderr,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE specifies unexpected address size: %d\n",
+ filename_.c_str(), offset, section_.c_str(), address_size);
+}
+
+void CallFrameInfo::Reporter::UnexpectedSegmentSize(uint64 offset,
+ uint8_t segment_size) {
+ fprintf(stderr,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE specifies unexpected segment size: %d\n",
+ filename_.c_str(), offset, section_.c_str(), segment_size);
+}
+
+void CallFrameInfo::Reporter::UnrecognizedVersion(uint64 offset, int version) {
+ fprintf(stderr,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE specifies unrecognized version: %d\n",
+ filename_.c_str(), offset, section_.c_str(), version);
+}
+
+void CallFrameInfo::Reporter::UnrecognizedAugmentation(uint64 offset,
+ const string &aug) {
+ fprintf(stderr,
+ "%s: CFI frame description entry at offset 0x%llx in '%s':"
+ " CIE specifies unrecognized augmentation: '%s'\n",
+ filename_.c_str(), offset, section_.c_str(), aug.c_str());
+}
+
+void CallFrameInfo::Reporter::InvalidPointerEncoding(uint64 offset,
+ uint8 encoding) {
+ fprintf(stderr,
+ "%s: CFI common information entry at offset 0x%llx in '%s':"
+ " 'z' augmentation specifies invalid pointer encoding: 0x%02x\n",
+ filename_.c_str(), offset, section_.c_str(), encoding);
+}
+
+void CallFrameInfo::Reporter::UnusablePointerEncoding(uint64 offset,
+ uint8 encoding) {
+ fprintf(stderr,
+ "%s: CFI common information entry at offset 0x%llx in '%s':"
+ " 'z' augmentation specifies a pointer encoding for which"
+ " we have no base address: 0x%02x\n",
+ filename_.c_str(), offset, section_.c_str(), encoding);
+}
+
+void CallFrameInfo::Reporter::RestoreInCIE(uint64 offset, uint64 insn_offset) {
+ fprintf(stderr,
+ "%s: CFI common information entry at offset 0x%llx in '%s':"
+ " the DW_CFA_restore instruction at offset 0x%llx"
+ " cannot be used in a common information entry\n",
+ filename_.c_str(), offset, section_.c_str(), insn_offset);
+}
+
+void CallFrameInfo::Reporter::BadInstruction(uint64 offset,
+ CallFrameInfo::EntryKind kind,
+ uint64 insn_offset) {
+ fprintf(stderr,
+ "%s: CFI %s at offset 0x%llx in section '%s':"
+ " the instruction at offset 0x%llx is unrecognized\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind),
+ offset, section_.c_str(), insn_offset);
+}
+
+void CallFrameInfo::Reporter::NoCFARule(uint64 offset,
+ CallFrameInfo::EntryKind kind,
+ uint64 insn_offset) {
+ fprintf(stderr,
+ "%s: CFI %s at offset 0x%llx in section '%s':"
+ " the instruction at offset 0x%llx assumes that a CFA rule has"
+ " been set, but none has been set\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind), offset,
+ section_.c_str(), insn_offset);
+}
+
+void CallFrameInfo::Reporter::EmptyStateStack(uint64 offset,
+ CallFrameInfo::EntryKind kind,
+ uint64 insn_offset) {
+ fprintf(stderr,
+ "%s: CFI %s at offset 0x%llx in section '%s':"
+ " the DW_CFA_restore_state instruction at offset 0x%llx"
+ " should pop a saved state from the stack, but the stack is empty\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind), offset,
+ section_.c_str(), insn_offset);
+}
+
+void CallFrameInfo::Reporter::ClearingCFARule(uint64 offset,
+ CallFrameInfo::EntryKind kind,
+ uint64 insn_offset) {
+ fprintf(stderr,
+ "%s: CFI %s at offset 0x%llx in section '%s':"
+ " the DW_CFA_restore_state instruction at offset 0x%llx"
+ " would clear the CFA rule in effect\n",
+ filename_.c_str(), CallFrameInfo::KindName(kind), offset,
+ section_.c_str(), insn_offset);
+}
+
+} // namespace dwarf2reader