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Differential D93444

Make DWARFUnit use the dwo_id from the DWARF5 CU header.
ClosedPublic

Authored by jgorbe on Dec 16 2020, 9:59 PM.

Details

Reviewers
labath
Commits
rGa39b19821b6b: Make DWARFUnit use the dwo_id from the DWARF5 CU header.
Summary

In split DWARF v5 files, the DWO id is no longer in the DW_AT_GNU_dwo_id
attribute. It's in the CU header instead. This change makes lldb look in
both places.

Diff Detail

Event Timeline

jgorbe requested review of this revision.Dec 16 2020, 9:59 PM
jgorbe created this revision.
Herald added a project: Restricted Project. · View Herald TranscriptDec 16 2020, 9:59 PM
Harbormaster completed remote builds in B82733: Diff 312377.Dec 16 2020, 10:39 PM
Herald added a subscriber: JDevlieghere. · View Herald TranscriptDec 16 2020, 10:39 PM
labath accepted this revision.Dec 21 2020, 11:47 AM
This revision is now accepted and ready to land.Dec 21 2020, 11:47 AM
jgorbe added a comment.Jan 5 2021, 3:44 PM

Thanks for accepting the patch! (and sorry for the late reply, I was on vacation). I'll commit this now :)

This revision was landed with ongoing or failed builds.Jan 5 2021, 4:40 PM
Closed by commit rGa39b19821b6b: Make DWARFUnit use the dwo_id from the DWARF5 CU header. (authored by jgorbe). · Explain Why
This revision was automatically updated to reflect the committed changes.
jgorbe added a commit: rGa39b19821b6b: Make DWARFUnit use the dwo_id from the DWARF5 CU header..

Revision Contents

PathSize
lldb/
source/
Plugins/
SymbolFile/
DWARF/
4 lines
19 lines
3 lines
test/
Shell/
SymbolFile/
DWARF/
235 lines

Diff 314753

lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h

Show First 20 Lines • Show All 59 Lines • ▼ Show 20 Linespublic:
dw_offset_t GetLength() const { return m_length; } dw_offset_t GetLength() const { return m_length; }
dw_offset_t GetAbbrOffset() const { return m_abbr_offset; } dw_offset_t GetAbbrOffset() const { return m_abbr_offset; }
uint8_t GetUnitType() const { return m_unit_type; } uint8_t GetUnitType() const { return m_unit_type; }
const llvm::DWARFUnitIndex::Entry *GetIndexEntry() const { const llvm::DWARFUnitIndex::Entry *GetIndexEntry() const {
return m_index_entry; return m_index_entry;
} }
uint64_t GetTypeHash() const { return m_type_hash; } uint64_t GetTypeHash() const { return m_type_hash; }
dw_offset_t GetTypeOffset() const { return m_type_offset; } dw_offset_t GetTypeOffset() const { return m_type_offset; }
uint64_t GetDWOId() const { return m_dwo_id; }
bool IsTypeUnit() const { bool IsTypeUnit() const {
return m_unit_type == DW_UT_type || m_unit_type == DW_UT_split_type; return m_unit_type == DW_UT_type || m_unit_type == DW_UT_split_type;
} }
uint32_t GetNextUnitOffset() const { return m_offset + m_length + 4; } uint32_t GetNextUnitOffset() const { return m_offset + m_length + 4; }
static llvm::Expected<DWARFUnitHeader> static llvm::Expected<DWARFUnitHeader>
extract(const lldb_private::DWARFDataExtractor &data, DIERef::Section section, extract(const lldb_private::DWARFDataExtractor &data, DIERef::Section section,
lldb::offset_t *offset_ptr, const llvm::DWARFUnitIndex *index); lldb::offset_t *offset_ptr, const llvm::DWARFUnitIndex *index);
}; };
class DWARFUnit : public lldb_private::UserID { class DWARFUnit : public lldb_private::UserID {
using die_iterator_range = using die_iterator_range =
llvm::iterator_range<DWARFDebugInfoEntry::collection::iterator>; llvm::iterator_range<DWARFDebugInfoEntry::collection::iterator>;
public: public:
static llvm::Expected<DWARFUnitSP> static llvm::Expected<DWARFUnitSP>
extract(SymbolFileDWARF &dwarf2Data, lldb::user_id_t uid, extract(SymbolFileDWARF &dwarf2Data, lldb::user_id_t uid,
const lldb_private::DWARFDataExtractor &debug_info, const lldb_private::DWARFDataExtractor &debug_info,
DIERef::Section section, lldb::offset_t *offset_ptr, DIERef::Section section, lldb::offset_t *offset_ptr,
const llvm::DWARFUnitIndex *index); const llvm::DWARFUnitIndex *index);
virtual ~DWARFUnit(); virtual ~DWARFUnit();
bool IsDWOUnit() { return m_is_dwo; } bool IsDWOUnit() { return m_is_dwo; }
uint64_t GetDWOId();
void ExtractUnitDIEIfNeeded(); void ExtractUnitDIEIfNeeded();
void ExtractDIEsIfNeeded(); void ExtractDIEsIfNeeded();
class ScopedExtractDIEs { class ScopedExtractDIEs {
DWARFUnit *m_cu; DWARFUnit *m_cu;
public: public:
bool m_clear_dies = false; bool m_clear_dies = false;
▲ Show 20 Lines • Show All 229 Lines • ▼ Show 20 Linesprotected:
dw_offset_t m_str_offsets_base = 0; // Value of DW_AT_str_offsets_base. dw_offset_t m_str_offsets_base = 0; // Value of DW_AT_str_offsets_base.
llvm::Optional<llvm::DWARFDebugRnglistTable> m_rnglist_table; llvm::Optional<llvm::DWARFDebugRnglistTable> m_rnglist_table;
llvm::Optional<llvm::DWARFListTableHeader> m_loclist_table_header; llvm::Optional<llvm::DWARFListTableHeader> m_loclist_table_header;
const DIERef::Section m_section; const DIERef::Section m_section;
bool m_is_dwo; bool m_is_dwo;
/// Value of DW_AT_GNU_dwo_id (v4) or dwo_id from CU header (v5).
uint64_t m_dwo_id;
private: private:
void ParseProducerInfo(); void ParseProducerInfo();
void ExtractDIEsRWLocked(); void ExtractDIEsRWLocked();
void ClearDIEsRWLocked(); void ClearDIEsRWLocked();
void AddUnitDIE(const DWARFDebugInfoEntry &cu_die); void AddUnitDIE(const DWARFDebugInfoEntry &cu_die);
void SetDwoStrOffsetsBase(); void SetDwoStrOffsetsBase();
Show All 9 Lines

lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp

Show All 28 Lines
extern int g_verbose; extern int g_verbose;
DWARFUnit::DWARFUnit(SymbolFileDWARF &dwarf, lldb::user_id_t uid, DWARFUnit::DWARFUnit(SymbolFileDWARF &dwarf, lldb::user_id_t uid,
const DWARFUnitHeader &header, const DWARFUnitHeader &header,
const DWARFAbbreviationDeclarationSet &abbrevs, const DWARFAbbreviationDeclarationSet &abbrevs,
DIERef::Section section, bool is_dwo) DIERef::Section section, bool is_dwo)
: UserID(uid), m_dwarf(dwarf), m_header(header), m_abbrevs(&abbrevs), : UserID(uid), m_dwarf(dwarf), m_header(header), m_abbrevs(&abbrevs),
m_cancel_scopes(false), m_section(section), m_is_dwo(is_dwo) {} m_cancel_scopes(false), m_section(section), m_is_dwo(is_dwo),
m_dwo_id(header.GetDWOId()) {}
DWARFUnit::~DWARFUnit() = default; DWARFUnit::~DWARFUnit() = default;
// Parses first DIE of a compile unit. // Parses first DIE of a compile unit.
void DWARFUnit::ExtractUnitDIEIfNeeded() { void DWARFUnit::ExtractUnitDIEIfNeeded() {
{ {
llvm::sys::ScopedReader lock(m_first_die_mutex); llvm::sys::ScopedReader lock(m_first_die_mutex);
if (m_first_die) if (m_first_die)
▲ Show 20 Lines • Show All 233 Lines • ▼ Show 20 Lines if (GetVersion() >= 5) {
// Skip padding. // Skip padding.
baseOffset += 2; baseOffset += 2;
} }
SetStrOffsetsBase(baseOffset); SetStrOffsetsBase(baseOffset);
} }
uint64_t DWARFUnit::GetDWOId() {
ExtractUnitDIEIfNeeded();
return m_dwo_id;
}
// m_die_array_mutex must be already held as read/write. // m_die_array_mutex must be already held as read/write.
void DWARFUnit::AddUnitDIE(const DWARFDebugInfoEntry &cu_die) { void DWARFUnit::AddUnitDIE(const DWARFDebugInfoEntry &cu_die) {
llvm::Optional<uint64_t> addr_base, gnu_addr_base, ranges_base, llvm::Optional<uint64_t> addr_base, gnu_addr_base, ranges_base,
gnu_ranges_base; gnu_ranges_base;
DWARFAttributes attributes; DWARFAttributes attributes;
size_t num_attributes = cu_die.GetAttributes(this, attributes); size_t num_attributes = cu_die.GetAttributes(this, attributes);
Show All 37 Lines case DW_AT_stmt_list:
m_line_table_offset = form_value.Unsigned(); m_line_table_offset = form_value.Unsigned();
break; break;
case DW_AT_GNU_addr_base: case DW_AT_GNU_addr_base:
gnu_addr_base = form_value.Unsigned(); gnu_addr_base = form_value.Unsigned();
break; break;
case DW_AT_GNU_ranges_base: case DW_AT_GNU_ranges_base:
gnu_ranges_base = form_value.Unsigned(); gnu_ranges_base = form_value.Unsigned();
break; break;
case DW_AT_GNU_dwo_id:
m_dwo_id = form_value.Unsigned();
break;
} }
} }
if (m_is_dwo) { if (m_is_dwo) {
SetDwoStrOffsetsBase(); SetDwoStrOffsetsBase();
return; return;
} }
std::shared_ptr<SymbolFileDWARFDwo> dwo_symbol_file = std::shared_ptr<SymbolFileDWARFDwo> dwo_symbol_file =
m_dwarf.GetDwoSymbolFileForCompileUnit(*this, cu_die); m_dwarf.GetDwoSymbolFileForCompileUnit(*this, cu_die);
if (!dwo_symbol_file) if (!dwo_symbol_file)
return; return;
uint64_t main_dwo_id = DWARFUnit *dwo_cu = dwo_symbol_file->GetDWOCompileUnitForHash(m_dwo_id);
cu_die.GetAttributeValueAsUnsigned(this, DW_AT_GNU_dwo_id, 0);
DWARFUnit *dwo_cu = dwo_symbol_file->GetDWOCompileUnitForHash(main_dwo_id);
if (!dwo_cu) if (!dwo_cu)
return; // Can't fetch the compile unit from the dwo file. return; // Can't fetch the compile unit from the dwo file.
dwo_cu->SetUserData(this); dwo_cu->SetUserData(this);
DWARFBaseDIE dwo_cu_die = dwo_cu->GetUnitDIEOnly(); DWARFBaseDIE dwo_cu_die = dwo_cu->GetUnitDIEOnly();
if (!dwo_cu_die.IsValid()) if (!dwo_cu_die.IsValid())
return; // Can't fetch the compile unit DIE from the dwo file. return; // Can't fetch the compile unit DIE from the dwo file.
▲ Show 20 Lines • Show All 419 Lines • ▼ Show 20 LinesDWARFUnitHeader::extract(const DWARFDataExtractor &data,
if (index) if (index)
header.m_index_entry = index->getFromOffset(*offset_ptr); header.m_index_entry = index->getFromOffset(*offset_ptr);
header.m_length = data.GetDWARFInitialLength(offset_ptr); header.m_length = data.GetDWARFInitialLength(offset_ptr);
header.m_version = data.GetU16(offset_ptr); header.m_version = data.GetU16(offset_ptr);
if (header.m_version == 5) { if (header.m_version == 5) {
header.m_unit_type = data.GetU8(offset_ptr); header.m_unit_type = data.GetU8(offset_ptr);
header.m_addr_size = data.GetU8(offset_ptr); header.m_addr_size = data.GetU8(offset_ptr);
header.m_abbr_offset = data.GetDWARFOffset(offset_ptr); header.m_abbr_offset = data.GetDWARFOffset(offset_ptr);
if (header.m_unit_type == llvm::dwarf::DW_UT_skeleton) if (header.m_unit_type == llvm::dwarf::DW_UT_skeleton ||
header.m_unit_type == llvm::dwarf::DW_UT_split_compile)
header.m_dwo_id = data.GetU64(offset_ptr); header.m_dwo_id = data.GetU64(offset_ptr);
} else { } else {
header.m_abbr_offset = data.GetDWARFOffset(offset_ptr); header.m_abbr_offset = data.GetDWARFOffset(offset_ptr);
header.m_addr_size = data.GetU8(offset_ptr); header.m_addr_size = data.GetU8(offset_ptr);
header.m_unit_type = header.m_unit_type =
section == DIERef::Section::DebugTypes ? DW_UT_type : DW_UT_compile; section == DIERef::Section::DebugTypes ? DW_UT_type : DW_UT_compile;
} }
▲ Show 20 Lines • Show All 166 Lines • Show Last 20 Lines

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.cpp

Show First 20 Lines • Show All 43 Lines • ▼ Show 20 Lines if (const llvm::DWARFUnitIndex::Entry *entry = index.getFromHash(hash)) {
unit_contrib->Offset)); unit_contrib->Offset));
} }
return nullptr; return nullptr;
} }
DWARFCompileUnit *cu = FindSingleCompileUnit(); DWARFCompileUnit *cu = FindSingleCompileUnit();
if (!cu) if (!cu)
return nullptr; return nullptr;
if (hash != if (hash != cu->GetDWOId())
cu->GetUnitDIEOnly().GetAttributeValueAsUnsigned(DW_AT_GNU_dwo_id, 0))
return nullptr; return nullptr;
return cu; return cu;
} }
DWARFCompileUnit *SymbolFileDWARFDwo::FindSingleCompileUnit() { DWARFCompileUnit *SymbolFileDWARFDwo::FindSingleCompileUnit() {
DWARFDebugInfo &debug_info = DebugInfo(); DWARFDebugInfo &debug_info = DebugInfo();
// Right now we only support dwo files with one compile unit. If we don't have // Right now we only support dwo files with one compile unit. If we don't have
▲ Show 20 Lines • Show All 70 Lines • Show Last 20 Lines

lldb/test/Shell/SymbolFile/DWARF/dwarf5-split.s

  • This file was added.
## This test checks that lldb reads debug info from a dwp file when the dwo_id
## is in a DWARF5 CU header instead of a DW_AT_GNU_dwo_id attribute.
# RUN: llvm-mc --filetype=obj --triple x86_64 %s -o %t --defsym MAIN=1
# RUN: llvm-mc --filetype=obj --triple x86_64 %s -o %t.dwp
# RUN: %lldb %t -o "target variable i" -b | FileCheck %s
# CHECK: (int) i = 42
.ifdef MAIN
## Main file
.text
.globl main # -- Begin function main
main: # @main
.Lfunc_begin0:
pushq %rbp
movq %rsp, %rbp
xorl %eax, %eax
popq %rbp
retq
.Lfunc_end0:
# -- End function
.data
i:
.long 42 # 0x2a
.section .debug_abbrev,"",@progbits
.byte 1 # Abbreviation Code
.byte 74 # DW_TAG_skeleton_unit
.byte 0 # DW_CHILDREN_no
.byte 118 # DW_AT_dwo_name
.byte 8 # DW_FORM_string
.byte 17 # DW_AT_low_pc
.byte 27 # DW_FORM_addrx
.byte 18 # DW_AT_high_pc
.byte 6 # DW_FORM_data4
.byte 115 # DW_AT_addr_base
.byte 23 # DW_FORM_sec_offset
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 0 # EOM(3)
.section .debug_info,"",@progbits
.Lcu_begin0:
.long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
.Ldebug_info_start0:
.short 5 # DWARF version number
.byte 4 # DWARF Unit Type
.byte 8 # Address Size (in bytes)
.long .debug_abbrev # Offset Into Abbrev. Section
.quad 1026699901672188186 # dwo_id
.byte 1 # Abbrev [1] 0x14:0x14 DW_TAG_skeleton_unit
.asciz "hello.dwo" # DW_AT_dwo_name
.byte 1 # DW_AT_low_pc
.long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
.long .Laddr_table_base0 # DW_AT_addr_base
.Ldebug_info_end0:
.section .debug_addr,"",@progbits
.long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
.Ldebug_addr_start0:
.short 5 # DWARF version number
.byte 8 # Address size
.byte 0 # Segment selector size
.Laddr_table_base0:
.quad i
.quad .Lfunc_begin0
.Ldebug_addr_end0:
.else
## DWP file
.section .debug_str_offsets.dwo,"e",@progbits
.long 28
.short 5
.short 0
.section .debug_str.dwo,"eMS",@progbits,1
.Linfo_string0:
.asciz "i"
.Linfo_string1:
.asciz "int"
.Linfo_string2:
.asciz "main"
.Linfo_string3:
.asciz "hand-tuned clang output"
.Linfo_string4:
.asciz "hello.c"
.Linfo_string5:
.asciz "hello.dwo"
.section .debug_str_offsets.dwo,"e",@progbits
.long .Linfo_string0-.debug_str.dwo
.long .Linfo_string1-.debug_str.dwo
.long .Linfo_string2-.debug_str.dwo
.long .Linfo_string3-.debug_str.dwo
.long .Linfo_string4-.debug_str.dwo
.long .Linfo_string5-.debug_str.dwo
.Lstr_offsets_end:
.section .debug_info.dwo,"e",@progbits
.long .Ldebug_info_dwo_end0-.Ldebug_info_dwo_start0 # Length of Unit
.Ldebug_info_dwo_start0:
.short 5 # DWARF version number
.byte 5 # DWARF Unit Type
.byte 8 # Address Size (in bytes)
.long 0 # Offset Into Abbrev. Section
.quad 1026699901672188186 # dwo_id
.byte 1 # Abbrev [1] 0x14:0x25 DW_TAG_compile_unit
.byte 3 # DW_AT_producer
.short 12 # DW_AT_language
.byte 4 # DW_AT_name
.byte 5 # DW_AT_dwo_name
.byte 2 # Abbrev [2] 0x1a:0xb DW_TAG_variable
.byte 0 # DW_AT_name
.long 37 # DW_AT_type
# DW_AT_external
.byte 0 # DW_AT_decl_file
.byte 2 # DW_AT_decl_line
.byte 2 # DW_AT_location
.byte 161
.byte 0
.byte 3 # Abbrev [3] 0x25:0x4 DW_TAG_base_type
.byte 1 # DW_AT_name
.byte 5 # DW_AT_encoding
.byte 4 # DW_AT_byte_size
.byte 4 # Abbrev [4] 0x29:0xf DW_TAG_subprogram
.byte 1 # DW_AT_low_pc
.long 8 # DW_AT_high_pc
.byte 1 # DW_AT_frame_base
.byte 86
.byte 2 # DW_AT_name
.byte 0 # DW_AT_decl_file
.byte 3 # DW_AT_decl_line
.long 37 # DW_AT_type
# DW_AT_external
.byte 0 # End Of Children Mark
.Ldebug_info_dwo_end0:
.section .debug_abbrev.dwo,"e",@progbits
.byte 1 # Abbreviation Code
.byte 17 # DW_TAG_compile_unit
.byte 1 # DW_CHILDREN_yes
.byte 37 # DW_AT_producer
.byte 37 # DW_FORM_strx1
.byte 19 # DW_AT_language
.byte 5 # DW_FORM_data2
.byte 3 # DW_AT_name
.byte 37 # DW_FORM_strx1
.byte 118 # DW_AT_dwo_name
.byte 37 # DW_FORM_strx1
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 2 # Abbreviation Code
.byte 52 # DW_TAG_variable
.byte 0 # DW_CHILDREN_no
.byte 3 # DW_AT_name
.byte 37 # DW_FORM_strx1
.byte 73 # DW_AT_type
.byte 19 # DW_FORM_ref4
.byte 63 # DW_AT_external
.byte 25 # DW_FORM_flag_present
.byte 58 # DW_AT_decl_file
.byte 11 # DW_FORM_data1
.byte 59 # DW_AT_decl_line
.byte 11 # DW_FORM_data1
.byte 2 # DW_AT_location
.byte 24 # DW_FORM_exprloc
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 3 # Abbreviation Code
.byte 36 # DW_TAG_base_type
.byte 0 # DW_CHILDREN_no
.byte 3 # DW_AT_name
.byte 37 # DW_FORM_strx1
.byte 62 # DW_AT_encoding
.byte 11 # DW_FORM_data1
.byte 11 # DW_AT_byte_size
.byte 11 # DW_FORM_data1
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 4 # Abbreviation Code
.byte 46 # DW_TAG_subprogram
.byte 0 # DW_CHILDREN_no
.byte 17 # DW_AT_low_pc
.byte 27 # DW_FORM_addrx
.byte 18 # DW_AT_high_pc
.byte 6 # DW_FORM_data4
.byte 64 # DW_AT_frame_base
.byte 24 # DW_FORM_exprloc
.byte 3 # DW_AT_name
.byte 37 # DW_FORM_strx1
.byte 58 # DW_AT_decl_file
.byte 11 # DW_FORM_data1
.byte 59 # DW_AT_decl_line
.byte 11 # DW_FORM_data1
.byte 73 # DW_AT_type
.byte 19 # DW_FORM_ref4
.byte 63 # DW_AT_external
.byte 25 # DW_FORM_flag_present
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 0 # EOM(3)
.Ldebug_abbrev_end:
.section .debug_cu_index,"",@progbits
.short 5 # DWARF version number
.short 0 # Reserved
.long 3 # Section count
.long 1 # Unit count
.long 2 # Slot count
.quad 1026699901672188186, 0 # Hash table
.long 1, 0 # Index table
## Table header
.long 1 # DW_SECT_INFO
.long 3 # DW_SECT_ABBREV
.long 6 # DW_SECT_STR_OFFSETS
## Offsets
.long 0 # offset into .debug_info.dwo
.long 0 # offset into .debug_abbrev.dwo
.long 0 # offset into .debug_str_offsets.dwo
## Sizes
.long .Ldebug_info_dwo_end0 - .debug_info.dwo
.long .Ldebug_abbrev_end - .debug_abbrev.dwo
.long .Lstr_offsets_end - .debug_str_offsets.dwo
.endif