From dbd454dbe47e584571388fc3533193416bdce67f Mon Sep 17 00:00:00 2001 From: Sterling Augustine Date: Fri, 13 Dec 2019 16:54:50 -0800 Subject: [PATCH] Add dwarf5 compilation-unit header handling. Fix a small typo in DW_LANG__Python. Change-Id: I1fe54e501a5e8da5057ecc9ac00c7e7259a9bb3f Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/1967975 Reviewed-by: Mark Mentovai --- src/common/dwarf/dwarf2enums.h | 2 +- src/common/dwarf/dwarf2reader.cc | 84 +++++++++++++++---- src/common/dwarf/dwarf2reader.h | 21 +++++ src/common/dwarf/dwarf2reader_die_unittest.cc | 6 +- src/common/dwarf/dwarf2reader_test_common.h | 10 ++- 5 files changed, 105 insertions(+), 18 deletions(-) diff --git a/src/common/dwarf/dwarf2enums.h b/src/common/dwarf/dwarf2enums.h index 51253ed4..b11a4fd1 100644 --- a/src/common/dwarf/dwarf2enums.h +++ b/src/common/dwarf/dwarf2enums.h @@ -686,7 +686,7 @@ enum DwarfLanguage DW_LANG_ObjC_plus_plus =0x0011, DW_LANG_UPC =0x0012, DW_LANG_D =0x0013, - DW_LANG__Python =0x0014, + DW_LANG_Python =0x0014, DW_LANG_OpenCL =0x0015, DW_LANG_Go =0x0016, DW_LANG_Modula3 =0x0017, diff --git a/src/common/dwarf/dwarf2reader.cc b/src/common/dwarf/dwarf2reader.cc index 3e6a3e89..7b8e043d 100644 --- a/src/common/dwarf/dwarf2reader.cc +++ b/src/common/dwarf/dwarf2reader.cc @@ -243,11 +243,51 @@ const uint8_t *CompilationUnit::SkipAttribute(const uint8_t *start, return NULL; } -// Read a DWARF2/3 header. -// The header is variable length in DWARF3 (and DWARF2 as extended by +// Read the abbreviation offset from a compilation unit header. +int CompilationUnit::ReadAbbrevOffset(const uint8_t *headerptr) { + assert(headerptr + reader_->OffsetSize() < buffer_ + buffer_length_); + header_.abbrev_offset = reader_->ReadOffset(headerptr); + return reader_->OffsetSize(); +} + +// Read the address size from a compilation unit header. +int CompilationUnit::ReadAddressSize(const uint8_t *headerptr) { + // 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); + return 1; +} + +// Read the DWO id from a split or skeleton compilation unit header. +int CompilationUnit::ReadDwoId(const uint8_t *headerptr) { + assert(headerptr + 8 <= buffer_ + buffer_length_); + dwo_id_ = reader_->ReadEightBytes(headerptr); + return 8; +} + +// Read the type signature from a type or split type compilation unit header. +int CompilationUnit::ReadTypeSignature(const uint8_t *headerptr) { + assert(headerptr + 8 <= buffer_ + buffer_length_); + type_signature_ = reader_->ReadEightBytes(headerptr); + return 8; +} + +// Read the DWO id from a split or skeleton compilation unit header. +int CompilationUnit::ReadTypeOffset(const uint8_t *headerptr) { + assert(headerptr + reader_->OffsetSize() < buffer_ + buffer_length_); + type_offset_ = reader_->ReadOffset(headerptr); + return reader_->OffsetSize(); +} + + +// Read a DWARF header. +// The header is variable length in DWARF3 and DWARF4 (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. +// address size. DWARF5 adds a unit_type to distinguish between +// partial-, full-, skeleton-, split-, and type- compilation units. void CompilationUnit::ReadHeader() { const uint8_t *headerptr = buffer_; size_t initial_length_size; @@ -262,17 +302,33 @@ void CompilationUnit::ReadHeader() { 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; - + if (header_.version <= 4) { + // Older versions of dwarf have a relatively simple structure. + headerptr += ReadAbbrevOffset(headerptr); + headerptr += ReadAddressSize(headerptr); + } else { + // DWARF5 adds a unit_type field, and various fields based on unit_type. + assert(headerptr + 1 < buffer_ + buffer_length_); + int unit_type = reader_->ReadOneByte(headerptr); + headerptr += 1; + headerptr += ReadAddressSize(headerptr); + headerptr += ReadAbbrevOffset(headerptr); + switch (unit_type) { + case DW_UT_compile: + case DW_UT_partial: + // nothing else to read + break; + case DW_UT_skeleton: + case DW_UT_split_compile: + headerptr += ReadDwoId(headerptr);; + break; + case DW_UT_type: + case DW_UT_split_type: + headerptr += ReadTypeSignature(headerptr);; + headerptr += ReadTypeOffset(headerptr);; + break; + } + } after_header_ = headerptr; // This check ensures that we don't have to do checking during the diff --git a/src/common/dwarf/dwarf2reader.h b/src/common/dwarf/dwarf2reader.h index 902d9ef1..6f1b1a4d 100644 --- a/src/common/dwarf/dwarf2reader.h +++ b/src/common/dwarf/dwarf2reader.h @@ -410,6 +410,21 @@ class CompilationUnit { // Reads the DWARF2/3 abbreviations for this compilation unit void ReadAbbrevs(); + // Read the abbreviation offset for this compilation unit + int ReadAbbrevOffset(const uint8_t *headerptr); + + // Read the address size for this compilation unit + int ReadAddressSize(const uint8_t *headerptr); + + // Read the DWO id from a split or skeleton compilation unit header + int ReadDwoId(const uint8_t *headerptr); + + // Read the type signature from a type or split type compilation unit header + int ReadTypeSignature(const uint8_t *headerptr); + + // Read the DWO id from a split or skeleton compilation unit header + int ReadTypeOffset(const uint8_t *headerptr); + // Processes a single DIE for this compilation unit and return a new // pointer just past the end of it const uint8_t *ProcessDIE(uint64 dieoffset, @@ -564,6 +579,12 @@ class CompilationUnit { // The value of the DW_AT_GNU_dwo_id attribute, if any. uint64 dwo_id_; + // The value of the DW_AT_GNU_type_signature attribute, if any. + uint64 type_signature_; + + // The value of the DW_AT_GNU_type_offset attribute, if any. + size_t type_offset_; + // The value of the DW_AT_GNU_dwo_name attribute, if any. const char* dwo_name_; diff --git a/src/common/dwarf/dwarf2reader_die_unittest.cc b/src/common/dwarf/dwarf2reader_die_unittest.cc index 71418eb8..60541ff5 100644 --- a/src/common/dwarf/dwarf2reader_die_unittest.cc +++ b/src/common/dwarf/dwarf2reader_die_unittest.cc @@ -217,6 +217,8 @@ INSTANTIATE_TEST_CASE_P( DwarfHeaderParams(kLittleEndian, 8, 3, 8), DwarfHeaderParams(kLittleEndian, 8, 4, 4), DwarfHeaderParams(kLittleEndian, 8, 4, 8), + DwarfHeaderParams(kLittleEndian, 8, 5, 4), + DwarfHeaderParams(kLittleEndian, 8, 5, 8), DwarfHeaderParams(kBigEndian, 4, 2, 4), DwarfHeaderParams(kBigEndian, 4, 2, 8), DwarfHeaderParams(kBigEndian, 4, 3, 4), @@ -228,7 +230,9 @@ INSTANTIATE_TEST_CASE_P( DwarfHeaderParams(kBigEndian, 8, 3, 4), DwarfHeaderParams(kBigEndian, 8, 3, 8), DwarfHeaderParams(kBigEndian, 8, 4, 4), - DwarfHeaderParams(kBigEndian, 8, 4, 8))); + DwarfHeaderParams(kBigEndian, 8, 4, 8), + DwarfHeaderParams(kBigEndian, 8, 5, 4), + DwarfHeaderParams(kBigEndian, 8, 5, 8))); struct DwarfFormsFixture: public DIEFixture { // Start a compilation unit, as directed by |params|, containing one diff --git a/src/common/dwarf/dwarf2reader_test_common.h b/src/common/dwarf/dwarf2reader_test_common.h index e91de906..545bc455 100644 --- a/src/common/dwarf/dwarf2reader_test_common.h +++ b/src/common/dwarf/dwarf2reader_test_common.h @@ -80,8 +80,14 @@ class TestCompilationUnit: public google_breakpad::test_assembler::Section { } post_length_offset_ = Size(); D16(version); - SectionOffset(abbrev_offset); - D8(address_size); + if (version <= 4) { + SectionOffset(abbrev_offset); + D8(address_size); + } else { + D8(0x01); // DW_UT_compile + D8(address_size); + SectionOffset(abbrev_offset); + } return *this; }