[Lldb-commits] [lldb] 979ca1c - Defer the decision whether to use the CU or TU index until after reading the unit header.
Jorge Gorbe Moya via lldb-commits
lldb-commits at lists.llvm.org
Tue Feb 23 13:26:26 PST 2021
Author: Jorge Gorbe Moya
Date: 2021-02-23T13:26:11-08:00
New Revision: 979ca1c05f83114483caec3e6d1b75daae86da79
URL: https://github.com/llvm/llvm-project/commit/979ca1c05f83114483caec3e6d1b75daae86da79
DIFF: https://github.com/llvm/llvm-project/commit/979ca1c05f83114483caec3e6d1b75daae86da79.diff
LOG: Defer the decision whether to use the CU or TU index until after reading the unit header.
In DWARF v4 compile units go in .debug_info and type units go in
.debug_types. However, in v5 both kinds of units are in .debug_info.
Therefore we can't decide whether to use the CU or TU index just by
looking at which section we're reading from. We have to wait until we
have read the unit type from the header.
Differential Revision: https://reviews.llvm.org/D96194
Added:
lldb/test/Shell/SymbolFile/DWARF/dwarf5_tu_index_abbrev_offset.s
Modified:
lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp
lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
Removed:
################################################################################
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp
index 8d393b295443..5f0af57da9e4 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp
@@ -72,16 +72,10 @@ void DWARFDebugInfo::ParseUnitsFor(DIERef::Section section) {
DWARFDataExtractor data = section == DIERef::Section::DebugTypes
? m_context.getOrLoadDebugTypesData()
: m_context.getOrLoadDebugInfoData();
- const llvm::DWARFUnitIndex *index = nullptr;
- if (m_context.isDwo())
- index = &llvm::getDWARFUnitIndex(m_context.GetAsLLVM(),
- section == DIERef::Section::DebugTypes
- ? llvm::DW_SECT_EXT_TYPES
- : llvm::DW_SECT_INFO);
lldb::offset_t offset = 0;
while (data.ValidOffset(offset)) {
llvm::Expected<DWARFUnitSP> unit_sp = DWARFUnit::extract(
- m_dwarf, m_units.size(), data, section, &offset, index);
+ m_dwarf, m_units.size(), data, section, &offset);
if (!unit_sp) {
// FIXME: Propagate this error up.
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
index a761dd3daac4..bb60ab9878c8 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
@@ -784,12 +784,11 @@ const DWARFDebugAranges &DWARFUnit::GetFunctionAranges() {
llvm::Expected<DWARFUnitHeader>
DWARFUnitHeader::extract(const DWARFDataExtractor &data,
- DIERef::Section section, lldb::offset_t *offset_ptr,
- const llvm::DWARFUnitIndex *index) {
+ DIERef::Section section,
+ lldb_private::DWARFContext &context,
+ lldb::offset_t *offset_ptr) {
DWARFUnitHeader header;
header.m_offset = *offset_ptr;
- if (index)
- header.m_index_entry = index->getFromOffset(*offset_ptr);
header.m_length = data.GetDWARFInitialLength(offset_ptr);
header.m_version = data.GetU16(offset_ptr);
if (header.m_version == 5) {
@@ -806,6 +805,16 @@ DWARFUnitHeader::extract(const DWARFDataExtractor &data,
section == DIERef::Section::DebugTypes ? DW_UT_type : DW_UT_compile;
}
+ if (context.isDwo()) {
+ if (header.IsTypeUnit()) {
+ header.m_index_entry =
+ context.GetAsLLVM().getTUIndex().getFromOffset(header.m_offset);
+ } else {
+ header.m_index_entry =
+ context.GetAsLLVM().getCUIndex().getFromOffset(header.m_offset);
+ }
+ }
+
if (header.m_index_entry) {
if (header.m_abbr_offset) {
return llvm::createStringError(
@@ -856,12 +865,11 @@ DWARFUnitHeader::extract(const DWARFDataExtractor &data,
llvm::Expected<DWARFUnitSP>
DWARFUnit::extract(SymbolFileDWARF &dwarf, user_id_t uid,
const DWARFDataExtractor &debug_info,
- DIERef::Section section, lldb::offset_t *offset_ptr,
- const llvm::DWARFUnitIndex *index) {
+ DIERef::Section section, lldb::offset_t *offset_ptr) {
assert(debug_info.ValidOffset(*offset_ptr));
- auto expected_header =
- DWARFUnitHeader::extract(debug_info, section, offset_ptr, index);
+ auto expected_header = DWARFUnitHeader::extract(
+ debug_info, section, dwarf.GetDWARFContext(), offset_ptr);
if (!expected_header)
return expected_header.takeError();
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
index 5739c36bbacb..0fc8ceae81d2 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
@@ -73,7 +73,8 @@ class DWARFUnitHeader {
static llvm::Expected<DWARFUnitHeader>
extract(const lldb_private::DWARFDataExtractor &data, DIERef::Section section,
- lldb::offset_t *offset_ptr, const llvm::DWARFUnitIndex *index);
+ lldb_private::DWARFContext &dwarf_context,
+ lldb::offset_t *offset_ptr);
};
class DWARFUnit : public lldb_private::UserID {
@@ -84,8 +85,7 @@ class DWARFUnit : public lldb_private::UserID {
static llvm::Expected<DWARFUnitSP>
extract(SymbolFileDWARF &dwarf2Data, lldb::user_id_t uid,
const lldb_private::DWARFDataExtractor &debug_info,
- DIERef::Section section, lldb::offset_t *offset_ptr,
- const llvm::DWARFUnitIndex *index);
+ DIERef::Section section, lldb::offset_t *offset_ptr);
virtual ~DWARFUnit();
bool IsDWOUnit() { return m_is_dwo; }
diff --git a/lldb/test/Shell/SymbolFile/DWARF/dwarf5_tu_index_abbrev_offset.s b/lldb/test/Shell/SymbolFile/DWARF/dwarf5_tu_index_abbrev_offset.s
new file mode 100644
index 000000000000..4dae81b48a68
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/dwarf5_tu_index_abbrev_offset.s
@@ -0,0 +1,323 @@
+## This test checks that lldb uses the abbrev_offset from .debug_tu_index when
+## reading TUs in the .debug_info section of a DWARF v5 DWP.
+##
+## The assembly here is, essentially, slightly hand-reduced output from
+## `clang -gsplit-dwarf -gdwarf-5 -fdebug-types-section`, with a manually-added
+## .debug_cu_index and a .debug_tu_index to create a DWP, and a twist: abbrevs
+## from the TU are listed *AFTER* abbrevs from the CU so that they don't begin
+## at offset 0.
+
+# 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 "image lookup -t t1" -b | FileCheck %s
+# CHECK: struct t1
+
+.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
+ .section .debug_abbrev,"", at 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,"", at 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 -8218585293556409984 # dwo_id
+ .byte 1 # Abbrev [1] 0x14:0x14 DW_TAG_skeleton_unit
+ .asciz "hello.dwo" # DW_AT_dwo_name
+ .byte 0 # 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,"", at 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 .Lfunc_begin0
+.Ldebug_addr_end0:
+
+
+.else
+## DWP file
+ .section .debug_info.dwo,"e", at progbits
+ .long .Ldebug_info_dwo_end0-.Ldebug_info_dwo_start0 # Length of Unit
+.Ldebug_info_dwo_start0:
+ .short 5 # DWARF version number
+ .byte 6 # DWARF Unit Type
+ .byte 8 # Address Size (in bytes)
+ .long 0 # Offset Into Abbrev. Section
+ .quad -4149699470930386446 # Type Signature
+ .long 31 # Type DIE Offset
+ .byte 1 # Abbrev [1] 0x18:0xe DW_TAG_type_unit
+ .short 33 # DW_AT_language
+ .long 0 # DW_AT_stmt_list
+ .byte 2 # Abbrev [2] 0x1f:0x6 DW_TAG_structure_type
+ .byte 5 # DW_AT_calling_convention
+ .byte 3 # DW_AT_name
+ .byte 1 # DW_AT_byte_size
+ .byte 0 # DW_AT_decl_file
+ .byte 1 # DW_AT_decl_line
+ .byte 0 # End Of Children Mark
+.Ldebug_info_dwo_end0:
+ .long .Ldebug_info_dwo_end1-.Ldebug_info_dwo_start1 # Length of Unit
+.Ldebug_info_dwo_start1:
+ .short 5 # DWARF version number
+ .byte 5 # DWARF Unit Type
+ .byte 8 # Address Size (in bytes)
+ .long 0 # Offset Into Abbrev. Section
+ .quad -8218585293556409984
+ .byte 3 # Abbrev [3] 0x14:0x2f DW_TAG_compile_unit
+ .byte 4 # DW_AT_producer
+ .short 33 # DW_AT_language
+ .byte 5 # DW_AT_name
+ .byte 6 # DW_AT_dwo_name
+ .byte 4 # Abbrev [4] 0x1a:0x1b DW_TAG_subprogram
+ .byte 0 # DW_AT_low_pc
+ .long 8 # DW_AT_high_pc
+ .byte 1 # DW_AT_frame_base
+ .byte 86
+ .byte 0 # DW_AT_name
+ .byte 0 # DW_AT_decl_file
+ .byte 2 # DW_AT_decl_line
+ .long 53 # DW_AT_type
+ # DW_AT_external
+ .byte 5 # Abbrev [5] 0x29:0xb DW_TAG_variable
+ .byte 2 # DW_AT_location
+ .byte 145
+ .byte 120
+ .byte 2 # DW_AT_name
+ .byte 0 # DW_AT_decl_file
+ .byte 3 # DW_AT_decl_line
+ .long 57 # DW_AT_type
+ .byte 0 # End Of Children Mark
+ .byte 6 # Abbrev [6] 0x35:0x4 DW_TAG_base_type
+ .byte 1 # DW_AT_name
+ .byte 5 # DW_AT_encoding
+ .byte 4 # DW_AT_byte_size
+ .byte 7 # Abbrev [7] 0x39:0x9 DW_TAG_structure_type
+ # DW_AT_declaration
+ .quad -4149699470930386446 # DW_AT_signature
+ .byte 0 # End Of Children Mark
+.Ldebug_info_dwo_end1:
+
+
+
+ .section .debug_str.dwo,"eMS", at progbits,1
+.Linfo_string0:
+ .asciz "main"
+.Linfo_string1:
+ .asciz "int"
+.Linfo_string2:
+ .asciz "v1"
+.Linfo_string3:
+ .asciz "t1"
+.Linfo_string4:
+ .asciz "hand-tuned clang output"
+.Linfo_string5:
+ .asciz "test.cc"
+.Linfo_string6:
+ .asciz "test.dwo"
+
+
+ .section .debug_str_offsets.dwo,"e", at progbits
+ .long 32 # Length of String Offsets Set
+ .short 5
+ .short 0
+
+ .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
+ .long .Linfo_string6-.debug_str.dwo
+.Lstr_offsets_end:
+
+ .section .debug_abbrev.dwo,"e", at progbits
+.Ldebug_cu_abbrev_begin:
+ .byte 3 # 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 4 # Abbreviation Code
+ .byte 46 # DW_TAG_subprogram
+ .byte 1 # DW_CHILDREN_yes
+ .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 5 # Abbreviation Code
+ .byte 52 # DW_TAG_variable
+ .byte 0 # DW_CHILDREN_no
+ .byte 2 # DW_AT_location
+ .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 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 6 # 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 7 # Abbreviation Code
+ .byte 19 # DW_TAG_structure_type
+ .byte 0 # DW_CHILDREN_no
+ .byte 60 # DW_AT_declaration
+ .byte 25 # DW_FORM_flag_present
+ .byte 105 # DW_AT_signature
+ .byte 32 # DW_FORM_ref_sig8
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 0 # EOM(3)
+.Ldebug_cu_abbrev_end:
+.Ldebug_tu_abbrev_begin:
+ .byte 1 # Abbreviation Code
+ .byte 65 # DW_TAG_type_unit
+ .byte 1 # DW_CHILDREN_yes
+ .byte 19 # DW_AT_language
+ .byte 5 # DW_FORM_data2
+ .byte 16 # DW_AT_stmt_list
+ .byte 23 # DW_FORM_sec_offset
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 2 # Abbreviation Code
+ .byte 19 # DW_TAG_structure_type
+ .byte 0 # DW_CHILDREN_no
+ .byte 54 # DW_AT_calling_convention
+ .byte 11 # DW_FORM_data1
+ .byte 3 # DW_AT_name
+ .byte 37 # DW_FORM_strx1
+ .byte 11 # DW_AT_byte_size
+ .byte 11 # DW_FORM_data1
+ .byte 58 # DW_AT_decl_file
+ .byte 11 # DW_FORM_data1
+ .byte 59 # DW_AT_decl_line
+ .byte 11 # DW_FORM_data1
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 0 # EOM(3)
+.Ldebug_tu_abbrev_end:
+.Ldebug_abbrev_dwo_end:
+
+.section .debug_tu_index,"", at progbits
+.short 5 # DWARF version number
+.short 0 # Reserved
+.long 3 # Section count
+.long 1 # Unit count
+.long 2 # Slot count
+
+.quad -4149699470930386446, 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 .Ldebug_tu_abbrev_begin - .debug_abbrev.dwo # offset into .debug_abbrev.dwo
+.long 0 # offset into .debug_str_offsets.dwo
+
+## Sizes
+.long .Ldebug_info_dwo_end0 - .debug_info.dwo
+.long .Ldebug_tu_abbrev_end - .Ldebug_tu_abbrev_begin
+.long .Lstr_offsets_end - .debug_str_offsets.dwo
+
+
+.section .debug_cu_index,"", at progbits
+.short 5 # DWARF version number
+.short 0 # Reserved
+.long 3 # Section count
+.long 1 # Unit count
+.long 2 # Slot count
+
+.quad -8218585293556409984, 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 .Ldebug_info_dwo_end0 - .debug_info.dwo # offset into .debug_info.dwo
+.long .Ldebug_cu_abbrev_begin - .debug_abbrev.dwo # offset into .debug_abbrev.dwo
+.long 0 # offset into .debug_str_offsets.dwo
+
+## Sizes
+.long .Ldebug_info_dwo_end1 - .Ldebug_info_dwo_end0
+.long .Ldebug_cu_abbrev_end - .Ldebug_cu_abbrev_begin
+.long .Lstr_offsets_end - .debug_str_offsets.dwo
+
+
+.endif
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