Read dwarf5 compilation unit headers.
Change-Id: Ia85b2fb7b3cb821ad353a0003223d8b8465e792d
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2265259
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
diff --git a/src/common/dwarf/dwarf2enums.h b/src/common/dwarf/dwarf2enums.h
index bed7032..2b93aba 100644
--- a/src/common/dwarf/dwarf2enums.h
+++ b/src/common/dwarf/dwarf2enums.h
@@ -115,6 +115,16 @@
DW_TAG_PGI_interface_block = 0xA020
};
+enum DwarfUnitHeader {
+ DW_UT_compile = 0x01,
+ DW_UT_type = 0x02,
+ DW_UT_partial = 0x03,
+ DW_UT_skeleton = 0x04,
+ DW_UT_split_compile = 0x05,
+ DW_UT_split_type = 0x06,
+ DW_UT_lo_user = 0x80,
+ DW_UT_hi_user = 0xFF
+};
enum DwarfHasChild {
DW_children_no = 0,
diff --git a/src/common/dwarf/dwarf2reader.cc b/src/common/dwarf/dwarf2reader.cc
index fbfff27..138f920 100644
--- a/src/common/dwarf/dwarf2reader.cc
+++ b/src/common/dwarf/dwarf2reader.cc
@@ -253,11 +253,50 @@
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.
+// Read the abbreviation offset from a compilation unit header.
+size_t 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.
+size_t 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.
+size_t 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.
+size_t 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.
+size_t 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. 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;
@@ -272,17 +311,36 @@
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_);
+ uint8_t 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;
+ default:
+ fprintf(stderr, "Unhandled compilation unit type 0x%x", unit_type);
+ 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 593f5c0..cd91b10 100644
--- a/src/common/dwarf/dwarf2reader.h
+++ b/src/common/dwarf/dwarf2reader.h
@@ -411,6 +411,21 @@
// Reads the DWARF2/3 abbreviations for this compilation unit
void ReadAbbrevs();
+ // Read the abbreviation offset for this compilation unit
+ size_t ReadAbbrevOffset(const uint8_t* headerptr);
+
+ // Read the address size for this compilation unit
+ size_t ReadAddressSize(const uint8_t* headerptr);
+
+ // Read the DWO id from a split or skeleton compilation unit header
+ size_t ReadDwoId(const uint8_t* headerptr);
+
+ // Read the type signature from a type or split type compilation unit header
+ size_t ReadTypeSignature(const uint8_t* headerptr);
+
+ // Read the DWO id from a split or skeleton compilation unit header
+ size_t 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_t dieoffset,
@@ -603,6 +618,12 @@
// The value of the DW_AT_GNU_dwo_id attribute, if any.
uint64_t dwo_id_;
+ // The value of the DW_AT_GNU_type_signature attribute, if any.
+ uint64_t 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 ca44cad..ab9f7cb 100644
--- a/src/common/dwarf/dwarf2reader_die_unittest.cc
+++ b/src/common/dwarf/dwarf2reader_die_unittest.cc
@@ -218,6 +218,8 @@
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),
@@ -229,7 +231,9 @@
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 e91de90..c81d54a 100644
--- a/src/common/dwarf/dwarf2reader_test_common.h
+++ b/src/common/dwarf/dwarf2reader_test_common.h
@@ -57,7 +57,7 @@
assert(format_size == 4 || format_size == 8);
format_size_ = format_size;
}
-
+
// Append a DWARF section offset value, of the appropriate size for this
// compilation unit.
template<typename T>
@@ -80,8 +80,14 @@
}
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;
}
