This is an archive of the discontinued LLVM Phabricator instance.

Differential D72597

[lldb][DWARF] Added support for new forms in DWARFv5 macro.
AbandonedPublic

Authored by SouraVX on Jan 13 2020, 3:47 AM.

Details

Reviewers
JDevlieghere
clayborg
labath
jdoerfert
shafik
Summary

This patch adds support for DWARFv5 new forms: DW_MACRO_define_strx, DW_MACRO_undef_strx.

Diff Detail

Event Timeline

SouraVX created this revision.Jan 13 2020, 3:47 AM
Herald added a reviewer: jdoerfert. · View Herald TranscriptJan 13 2020, 3:47 AM
Herald added subscribers: lldb-commits, aprantl. · View Herald Transcript
SouraVX marked an inline comment as done.Jan 13 2020, 3:49 AM
SouraVX added a subscriber: dblaikie.
SouraVX added inline comments.
lldb/test/Shell/Commands/Inputs/dwarf5-macro.s
2

This file is generated via clang/llvm with macro section support. -- will upstream that patch soon.

merge_guards_bot added a subscriber: merge_guards_bot.Jan 13 2020, 4:12 AM

Unit tests: pass. 61782 tests passed, 0 failed and 781 were skipped.

clang-tidy: unknown.

clang-format: pass.

Build artifacts: diff.json, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Harbormaster completed remote builds in B43815: Diff 237619.Jan 13 2020, 4:15 AM
clayborg added inline comments.Jan 13 2020, 10:15 AM
lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugMacro.cpp
58–59

We could also remove "offset_is_64_bit" if we fix DataExtractor to handle it as suggested below where "offset_is_64_bit" is used.

130–133

I have though about adding support to DataExtractor for extracting offsets. Anyone that initializes a DataExtractor would need to set the offset size once, and then everyone else could just call:

new_offset = debug_macro_data.GetOffset(offset);

We would need to add a field to DataExtractor:

Optional<uint32_t> m_offset_size; ///< The address size to use when extracting offsets. Defaults to m_addr_size if this has no value

It would default to the m_addr_size if m_offset_size isn't set. The "m_context.getOrLoadXXXX()" calls would then set the offset size correctly for the current DWARF when it creates the DWARFDataExtractor.

lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugMacro.h
55–58

To future proof this a bit should we pass in the "lldb_private::DWARFContext" instead of the first three arguments?

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
1055–1056

Move this into DWARFDebugMacroEntry::ReadMacroEntries() so that we don't have to pass "header" as an argument?

shafik added a reviewer: shafik.Jan 13 2020, 12:50 PM
shafik added a subscriber: shafik.
shafik added inline comments.
lldb/test/Shell/Commands/dwarf5-macro.test
2

Is there a reason why we would only want to test this feature on x86?

aprantl added inline comments.Jan 13 2020, 1:07 PM
lldb/test/Shell/Commands/dwarf5-macro.test
2

Presumably because the input is X86 assembly. That said, would it be possible to test the feature without constructing a process, so we *can* test it everywhere?

SouraVX updated this revision to Diff 237909.Jan 14 2020, 3:25 AM

Thank you everyone, for taking out time and reviewing this.
Addressed @clayborg review comments.

labath added a comment.Jan 14 2020, 3:30 AM

I have a high-level question/comment. Are you planning to implement debug_macro reading in llvm-dwarfdump? Even if you aren't, I am expecting that you will be asked to do that as a part of testing for your debug_macro generation patch... And in that case, it would be much better to write a debug_macro parser in first, and reuse that in lldb, similar to how its done for rnglists, loclists, and other "minor" sections. The slightly tricky part there is that you need to make sure to not intertwine it too much with other llvm dwarf classes, as lldb does not use all of llvm dwarf (yet). However, given that the debug_macro section is pretty independent, that shouldn't be too much of a problem?

lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugMacro.cpp
70

Surely, this should be set according to the actual str_offsets_base value, no?

SouraVX marked 4 inline comments as done.Jan 14 2020, 3:33 AM
SouraVX added inline comments.
lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugMacro.cpp
58–59

Agreed, however I think this enhancement has to be done separately.

lldb/test/Shell/Commands/dwarf5-macro.test
2

I tried, other ways also. Seems like this is bare minimum, We need to run the program to be able to expand macros. analogous behavior with GDB also.
If you've some better way in mind to test this. or where to put this. Please share.

SouraVX added a comment.Jan 14 2020, 3:41 AM
In D72597#1819164, @labath wrote:

I have a high-level question/comment. Are you planning to implement debug_macro reading in llvm-dwarfdump? Even if you aren't, I am expecting that you will be asked to do that as a part of testing for your debug_macro generation patch...

Hi Pavel, I've mostly completed debug_macro generation[clang/llvm] and dumping it using llvm-dwarfdump. I'll soon file a review for that also. Maybe we can address this concern while reviewing that. Till that, I think it would be nice to have minimum support for macros.

And in that case, it would be much better to write a debug_macro parser in first, and reuse that in lldb, similar to how its done for rnglists, loclists, and other "minor" sections. The slightly tricky part there is that you need to make sure to not intertwine it too much with other llvm dwarf classes, as lldb does not use all of llvm dwarf (yet). However, given that the debug_macro section is pretty independent, that shouldn't be too much of a problem?

labath added a comment.Jan 14 2020, 4:22 AM
In D72597#1819185, @SouraVX wrote:
In D72597#1819164, @labath wrote:

I have a high-level question/comment. Are you planning to implement debug_macro reading in llvm-dwarfdump? Even if you aren't, I am expecting that you will be asked to do that as a part of testing for your debug_macro generation patch...

Hi Pavel, I've mostly completed debug_macro generation[clang/llvm] and dumping it using llvm-dwarfdump. I'll soon file a review for that also. Maybe we can address this concern while reviewing that. Till that, I think it would be nice to have minimum support for macros.

I don't think this issue is particularly urgent -- a consumer is not very useful if you don't have a producer which can produce that data. And reusing the parser in llvm would allow us to largely drop the testing part of this discussion -- if the nitty-gritty encoding details are tested in llvm, then here we just need to make sure the integration works, and we already mostly have a test for that (TestMacros.py).

lldb/test/Shell/Commands/dwarf5-macro.test
2

It wouldn't be unreasonable to add some command to query active macro definitions at a given point in the program (similar to gdb's info macros command). In lldb, the best place to plug this into might be the "image lookup" command -- right now "image lookup --verbose --file a.cpp --line 10" will give you the function containing that line as well as all variables which are active at that point. It seems natural to also list the active macros too.

However, that would most likely require adding a new "macros" field to the SymbolContext class, which is a concept used throughout lldb, and so doing it may be fairly tricky and it may be better to create a separate command for this at first ("image dump macros"?)...

(also note that in the current form, this test will not only require x86, but also a linux (or at least elf) system)

SouraVX abandoned this revision.Mar 3 2021, 8:13 PM
Herald added a subscriber: sstefan1. · View Herald TranscriptMar 3 2021, 8:13 PM

Revision Contents

PathSize
lldb/
source/
Plugins/
SymbolFile/
DWARF/
11 lines
58 lines
7 lines
test/
Shell/
Commands/
Inputs/
266 lines
16 lines

Diff 237909

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

//===-- DWARFDebugMacro.h ----------------------------------------*- C++ //===-- DWARFDebugMacro.h ----------------------------------------*- C++
//-*-===// //-*-===//
// //
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information. // See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// //
//===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===//
#ifndef SymbolFileDWARF_DWARFDebugMacro_h_ #ifndef SymbolFileDWARF_DWARFDebugMacro_h_
#define SymbolFileDWARF_DWARFDebugMacro_h_ #define SymbolFileDWARF_DWARFDebugMacro_h_
#include <map> #include <map>
#include "DWARFContext.h"
#include "lldb/Core/dwarf.h" #include "lldb/Core/dwarf.h"
#include "lldb/Symbol/DebugMacros.h" #include "lldb/Symbol/DebugMacros.h"
#include "lldb/lldb-types.h" #include "lldb/lldb-types.h"
namespace lldb_private { namespace lldb_private {
class DWARFDataExtractor; class DWARFDataExtractor;
Show All 22 Linesprivate:
uint16_t m_version; uint16_t m_version;
bool m_offset_is_64_bit; bool m_offset_is_64_bit;
uint64_t m_debug_line_offset; uint64_t m_debug_line_offset;
}; };
class DWARFDebugMacroEntry { class DWARFDebugMacroEntry {
public: public:
static void static void ReadMacroEntries(lldb_private::DWARFContext &Context,
ReadMacroEntries(const lldb_private::DWARFDataExtractor &debug_macro_data, lldb::offset_t *sect_offset,
const lldb_private::DWARFDataExtractor &debug_str_data,
const bool offset_is_64_bit, lldb::offset_t *sect_offset,
SymbolFileDWARF *sym_file_dwarf, SymbolFileDWARF *sym_file_dwarf,
lldb_private::DebugMacrosSP &debug_macros_sp); lldb_private::DebugMacrosSP &debug_macros_sp);
}; };
clayborgUnsubmitted
Done
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To future proof this a bit should we pass in the "lldb_private::DWARFContext" instead of the first three arguments?

clayborg: To future proof this a bit should we pass in the "lldb_private::DWARFContext" instead of the…
#endif // SymbolFileDWARF_DWARFDebugMacro_h_ #endif // SymbolFileDWARF_DWARFDebugMacro_h_

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

Show First 20 Lines • Show All 49 Lines • ▼ Show 20 Lines for (uint8_t i = 0; i < entry_count; i++) {
uint64_t operand_count = debug_macro_data.GetULEB128(offset); uint64_t operand_count = debug_macro_data.GetULEB128(offset);
for (uint64_t j = 0; j < operand_count; j++) { for (uint64_t j = 0; j < operand_count; j++) {
// Skip over the operand form // Skip over the operand form
debug_macro_data.GetU8(offset); debug_macro_data.GetU8(offset);
} }
} }
} }
void DWARFDebugMacroEntry::ReadMacroEntries( void DWARFDebugMacroEntry::ReadMacroEntries(lldb_private::DWARFContext &Context,
clayborgUnsubmitted
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We could also remove "offset_is_64_bit" if we fix DataExtractor to handle it as suggested below where "offset_is_64_bit" is used.

clayborg: We could also remove "offset_is_64_bit" if we fix DataExtractor to handle it as suggested below…
SouraVXAuthorUnsubmitted
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Agreed, however I think this enhancement has to be done separately.

SouraVX: Agreed, however I think this enhancement has to be done separately.
const DWARFDataExtractor &debug_macro_data, lldb::offset_t *offset,
const DWARFDataExtractor &debug_str_data, const bool offset_is_64_bit, SymbolFileDWARF *sym_file_dwarf,
lldb::offset_t *offset, SymbolFileDWARF *sym_file_dwarf,
DebugMacrosSP &debug_macros_sp) { DebugMacrosSP &debug_macros_sp) {
llvm::dwarf::MacroEntryType type = const DWARFDebugMacroHeader &header =
static_cast<llvm::dwarf::MacroEntryType>(debug_macro_data.GetU8(offset)); DWARFDebugMacroHeader::ParseHeader(Context.getOrLoadMacroData(), offset);
llvm::dwarf::MacroEntryType type = static_cast<llvm::dwarf::MacroEntryType>(
Context.getOrLoadMacroData().GetU8(offset));
while (type != 0) { while (type != 0) {
lldb::offset_t new_offset = 0, str_offset = 0; lldb::offset_t new_offset = 0, str_offset = 0;
uint32_t line = 0; // For DWARF32 debug_str_offsets header size is 8 bytes.
uint8_t str_offsets_base = 8, index_size = 4;
labathUnsubmitted
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Surely, this should be set according to the actual str_offsets_base value, no?

labath: Surely, this should be set according to the actual str_offsets_base value, no?
uint32_t line = 0, str_index = 0;
const char *macro_str = nullptr; const char *macro_str = nullptr;
uint32_t debug_line_file_idx = 0; uint32_t debug_line_file_idx = 0;
bool offset_is_64_bit = header.OffsetIs64Bit();
switch (type) { switch (type) {
case DW_MACRO_define: case DW_MACRO_define:
case DW_MACRO_undef: case DW_MACRO_undef:
line = debug_macro_data.GetULEB128(offset); line = Context.getOrLoadMacroData().GetULEB128(offset);
macro_str = debug_macro_data.GetCStr(offset); macro_str = Context.getOrLoadMacroData().GetCStr(offset);
if (type == DW_MACRO_define) if (type == DW_MACRO_define)
debug_macros_sp->AddMacroEntry( debug_macros_sp->AddMacroEntry(
DebugMacroEntry::CreateDefineEntry(line, macro_str)); DebugMacroEntry::CreateDefineEntry(line, macro_str));
else else
debug_macros_sp->AddMacroEntry( debug_macros_sp->AddMacroEntry(
DebugMacroEntry::CreateUndefEntry(line, macro_str)); DebugMacroEntry::CreateUndefEntry(line, macro_str));
break; break;
case DW_MACRO_define_strp: case DW_MACRO_define_strp:
case DW_MACRO_undef_strp: case DW_MACRO_undef_strp:
line = debug_macro_data.GetULEB128(offset); line = Context.getOrLoadMacroData().GetULEB128(offset);
if (offset_is_64_bit) if (offset_is_64_bit)
str_offset = debug_macro_data.GetU64(offset); str_offset = Context.getOrLoadMacroData().GetU64(offset);
else else
str_offset = debug_macro_data.GetU32(offset); str_offset = Context.getOrLoadMacroData().GetU32(offset);
macro_str = debug_str_data.GetCStr(&str_offset); macro_str = Context.getOrLoadStrData().GetCStr(&str_offset);
if (type == DW_MACRO_define_strp) if (type == DW_MACRO_define_strp)
debug_macros_sp->AddMacroEntry( debug_macros_sp->AddMacroEntry(
DebugMacroEntry::CreateDefineEntry(line, macro_str)); DebugMacroEntry::CreateDefineEntry(line, macro_str));
else else
debug_macros_sp->AddMacroEntry( debug_macros_sp->AddMacroEntry(
DebugMacroEntry::CreateUndefEntry(line, macro_str)); DebugMacroEntry::CreateUndefEntry(line, macro_str));
break; break;
case DW_MACRO_define_strx:
case DW_MACRO_undef_strx:
line = Context.getOrLoadMacroData().GetULEB128(offset);
str_index = Context.getOrLoadMacroData().GetULEB128(offset);
str_offset = str_offsets_base + str_index * index_size;
str_offset =
Context.getOrLoadStrOffsetsData().GetMaxU64(&str_offset, index_size);
macro_str = Context.getOrLoadStrData().GetCStr(&str_offset);
if (type == DW_MACRO_define_strx)
debug_macros_sp->AddMacroEntry(
DebugMacroEntry::CreateDefineEntry(line, macro_str));
else
debug_macros_sp->AddMacroEntry(
DebugMacroEntry::CreateUndefEntry(line, macro_str));
break;
case DW_MACRO_start_file: case DW_MACRO_start_file:
line = debug_macro_data.GetULEB128(offset); line = Context.getOrLoadMacroData().GetULEB128(offset);
debug_line_file_idx = debug_macro_data.GetULEB128(offset); debug_line_file_idx = Context.getOrLoadMacroData().GetULEB128(offset);
debug_macros_sp->AddMacroEntry( debug_macros_sp->AddMacroEntry(
DebugMacroEntry::CreateStartFileEntry(line, debug_line_file_idx)); DebugMacroEntry::CreateStartFileEntry(line, debug_line_file_idx));
break; break;
case DW_MACRO_end_file: case DW_MACRO_end_file:
// This operation has no operands. // This operation has no operands.
debug_macros_sp->AddMacroEntry(DebugMacroEntry::CreateEndFileEntry()); debug_macros_sp->AddMacroEntry(DebugMacroEntry::CreateEndFileEntry());
break; break;
case DW_MACRO_import: case DW_MACRO_import:
if (offset_is_64_bit) if (offset_is_64_bit)
new_offset = debug_macro_data.GetU64(offset); new_offset = Context.getOrLoadMacroData().GetU64(offset);
else else
new_offset = debug_macro_data.GetU32(offset); new_offset = Context.getOrLoadMacroData().GetU32(offset);
clayborgUnsubmitted
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I have though about adding support to DataExtractor for extracting offsets. Anyone that initializes a DataExtractor would need to set the offset size once, and then everyone else could just call:

new_offset = debug_macro_data.GetOffset(offset);

We would need to add a field to DataExtractor:

Optional<uint32_t> m_offset_size; ///< The address size to use when extracting offsets. Defaults to m_addr_size if this has no value

It would default to the m_addr_size if m_offset_size isn't set. The "m_context.getOrLoadXXXX()" calls would then set the offset size correctly for the current DWARF when it creates the DWARFDataExtractor.

clayborg: I have though about adding support to DataExtractor for extracting offsets. Anyone that…
debug_macros_sp->AddMacroEntry(DebugMacroEntry::CreateIndirectEntry( debug_macros_sp->AddMacroEntry(DebugMacroEntry::CreateIndirectEntry(
sym_file_dwarf->ParseDebugMacros(&new_offset))); sym_file_dwarf->ParseDebugMacros(&new_offset)));
break; break;
default: default:
// TODO: Add support for other standard operations. // TODO: Add support for other standard operations.
// TODO: Provide mechanism to hook handling of non-standard/extension // TODO: Provide mechanism to hook handling of non-standard/extension
// operands. // operands.
return; return;
} }
type = static_cast<llvm::dwarf::MacroEntryType>( type = static_cast<llvm::dwarf::MacroEntryType>(
debug_macro_data.GetU8(offset)); Context.getOrLoadMacroData().GetU8(offset));
} }
} }

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

Show First 20 Lines • Show All 1,046 Lines • ▼ Show 20 Lines if (iter != m_debug_macros_map.end())
return iter->second; return iter->second;
const DWARFDataExtractor &debug_macro_data = m_context.getOrLoadMacroData(); const DWARFDataExtractor &debug_macro_data = m_context.getOrLoadMacroData();
if (debug_macro_data.GetByteSize() == 0) if (debug_macro_data.GetByteSize() == 0)
return DebugMacrosSP(); return DebugMacrosSP();
lldb_private::DebugMacrosSP debug_macros_sp(new lldb_private::DebugMacros()); lldb_private::DebugMacrosSP debug_macros_sp(new lldb_private::DebugMacros());
m_debug_macros_map[*offset] = debug_macros_sp; m_debug_macros_map[*offset] = debug_macros_sp;
const DWARFDebugMacroHeader &header = DWARFDebugMacroEntry::ReadMacroEntries(m_context, offset, this,
clayborgUnsubmitted
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Move this into DWARFDebugMacroEntry::ReadMacroEntries() so that we don't have to pass "header" as an argument?

clayborg: Move this into DWARFDebugMacroEntry::ReadMacroEntries() so that we don't have to pass "header"…
DWARFDebugMacroHeader::ParseHeader(debug_macro_data, offset); debug_macros_sp);
DWARFDebugMacroEntry::ReadMacroEntries(
debug_macro_data, m_context.getOrLoadStrData(), header.OffsetIs64Bit(),
offset, this, debug_macros_sp);
return debug_macros_sp; return debug_macros_sp;
} }
bool SymbolFileDWARF::ParseDebugMacros(CompileUnit &comp_unit) { bool SymbolFileDWARF::ParseDebugMacros(CompileUnit &comp_unit) {
std::lock_guard<std::recursive_mutex> guard(GetModuleMutex()); std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit); DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
▲ Show 20 Lines • Show All 2,923 Lines • Show Last 20 Lines

lldb/test/Shell/Commands/Inputs/dwarf5-macro.s

  • This file was added.
.text
.file "test.c"
SouraVXAuthorUnsubmitted
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This file is generated via clang/llvm with macro section support. -- will upstream that patch soon.

SouraVX: This file is generated via clang/llvm with macro section support. -- will upstream that patch…
.file 0 "/home/" "test.c" md5 0xef6a7032e0c7ceeef621583f2c00dc80
.globl main # -- Begin function main
.p2align 4, 0x90
.type main,@function
main: # @main
.Lfunc_begin0:
.loc 0 9 0 # test.c:9:0
.cfi_startproc
# %bb.0:
xorl %eax, %eax
.Ltmp0:
.loc 0 10 5 prologue_end # test.c:10:5
movl $3, -4(%rsp)
.loc 0 11 5 # test.c:11:5
movl $5, -8(%rsp)
.loc 0 12 1 # test.c:12:1
retq
.Ltmp1:
.Lfunc_end0:
.size main, .Lfunc_end0-main
.cfi_endproc
# -- End function
.section .debug_abbrev,"",@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 114 # DW_AT_str_offsets_base
.byte 23 # DW_FORM_sec_offset
.byte 16 # DW_AT_stmt_list
.byte 23 # DW_FORM_sec_offset
.byte 27 # DW_AT_comp_dir
.byte 37 # DW_FORM_strx1
.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 121 # DW_AT_macros
.byte 23 # DW_FORM_sec_offset
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 2 # 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 3 # 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 4 # 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 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 1 # DWARF Unit Type
.byte 8 # Address Size (in bytes)
.long .debug_abbrev # Offset Into Abbrev. Section
.byte 1 # Abbrev [1] 0xc:0x46 DW_TAG_compile_unit
.byte 0 # DW_AT_producer
.short 12 # DW_AT_language
.byte 1 # DW_AT_name
.long .Lstr_offsets_base0 # DW_AT_str_offsets_base
.long .Lline_table_start0 # DW_AT_stmt_list
.byte 2 # DW_AT_comp_dir
.byte 0 # DW_AT_low_pc
.long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
.long .Laddr_table_base0 # DW_AT_addr_base
.long .Lcu_macro_begin0-.debug_macro # DW_AT_macros
.byte 2 # Abbrev [2] 0x27:0x26 DW_TAG_subprogram
.byte 0 # DW_AT_low_pc
.long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
.byte 1 # DW_AT_frame_base
.byte 87
.byte 3 # DW_AT_name
.byte 0 # DW_AT_decl_file
.byte 9 # DW_AT_decl_line
.long 77 # DW_AT_type
# DW_AT_external
.byte 3 # Abbrev [3] 0x36:0xb DW_TAG_variable
.byte 2 # DW_AT_location
.byte 145
.byte 124
.byte 5 # DW_AT_name
.byte 0 # DW_AT_decl_file
.byte 10 # DW_AT_decl_line
.long 77 # DW_AT_type
.byte 3 # Abbrev [3] 0x41:0xb DW_TAG_variable
.byte 2 # DW_AT_location
.byte 145
.byte 120
.byte 6 # DW_AT_name
.byte 0 # DW_AT_decl_file
.byte 11 # DW_AT_decl_line
.long 77 # DW_AT_type
.byte 0 # End Of Children Mark
.byte 4 # Abbrev [4] 0x4d:0x4 DW_TAG_base_type
.byte 4 # DW_AT_name
.byte 5 # DW_AT_encoding
.byte 4 # DW_AT_byte_size
.byte 0 # End Of Children Mark
.Ldebug_info_end0:
.section .debug_macro,"",@progbits
.Lcu_macro_begin0:
.short 5 # Macro information version
.byte 2 # Flags: 32 bit, lineptr present
.long .Lline_table_start0 # lineptr
.byte 3 # DW_MACRO_start_file
.byte 0 # Line Number
.byte 0 # File Number
.byte 3 # DW_MACRO_start_file
.byte 1 # Line Number
.file 1 "." "foo.h" md5 0x0f0cd0e22b44f49d3944992c8dc28661 # File Number
.byte 1
.byte 11 # DW_MACRO_define_strx
.byte 1 # Line Number
.byte 7 # Macro String Index
.byte 4 # DW_MACRO_end_file
.byte 3 # DW_MACRO_start_file
.byte 2 # Line Number
.file 2 "." "bar.h" md5 0xbf4b34c333eaaa1d7085c25313b8d100 # File Number
.byte 2
.byte 11 # DW_MACRO_define_strx
.byte 1 # Line Number
.byte 8 # Macro String Index
.byte 4 # DW_MACRO_end_file
.byte 11 # DW_MACRO_define_strx
.byte 4 # Line Number
.byte 9 # Macro String Index
.byte 11 # DW_MACRO_define_strx
.byte 5 # Line Number
.byte 10 # Macro String Index
.byte 12 # DW_MACRO_undef_strx
.byte 14 # Line Number
.byte 11 # Macro String Index
.byte 4 # DW_MACRO_end_file
.byte 11 # DW_MACRO_define_strx
.byte 0 # Line Number
.byte 12 # Macro String Index
.byte 11 # DW_MACRO_define_strx
.byte 0 # Line Number
.byte 13 # Macro String Index
.byte 11 # DW_MACRO_define_strx
.byte 0 # Line Number
.byte 14 # Macro String Index
.byte 11 # DW_MACRO_define_strx
.byte 0 # Line Number
.byte 15 # Macro String Index
.byte 0 # End Of Macro List Mark
.section .debug_str_offsets,"",@progbits
.long 68
.short 5
.short 0
.Lstr_offsets_base0:
.section .debug_str,"MS",@progbits,1
.Linfo_string0:
.asciz "clang version 10.0.0" # string offset=0
.Linfo_string1:
.asciz "test.c" # string offset=21
.Linfo_string2:
.asciz "/home/" # string offset=28
.Linfo_string3:
.asciz "main" # string offset=35
.Linfo_string4:
.asciz "int" # string offset=40
.Linfo_string5:
.asciz "a" # string offset=44
.Linfo_string6:
.asciz "b" # string offset=46
.Linfo_string7:
.asciz "FOO 5" # string offset=48
.Linfo_string8:
.asciz "BAR 6" # string offset=54
.Linfo_string9:
.asciz "BAZ 7" # string offset=60
.Linfo_string10:
.asciz "YEA 8" # string offset=66
.Linfo_string11:
.asciz "YEA " # string offset=72
.Linfo_string12:
.asciz "__llvm__ 1" # string offset=77
.Linfo_string13:
.asciz "__clang__ 1" # string offset=88
.Linfo_string14:
.asciz "__clang_major__ 10" # string offset=100
.Linfo_string15:
.asciz "__clang_minor__ 0" # string offset=119
.section .debug_str_offsets,"",@progbits
.long .Linfo_string0
.long .Linfo_string1
.long .Linfo_string2
.long .Linfo_string3
.long .Linfo_string4
.long .Linfo_string5
.long .Linfo_string6
.long .Linfo_string7
.long .Linfo_string8
.long .Linfo_string9
.long .Linfo_string10
.long .Linfo_string11
.long .Linfo_string12
.long .Linfo_string13
.long .Linfo_string14
.long .Linfo_string15
.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 .Lfunc_begin0
.Ldebug_addr_end0:
.ident "clang version 10.0.0"
.section ".note.GNU-stack","",@progbits
.addrsig
.section .debug_line,"",@progbits
.Lline_table_start0:

lldb/test/Shell/Commands/dwarf5-macro.test

  • This file was added.
# REQUIRES: x86
# This test checks lldb macro expansion when macro section
shafikUnsubmitted
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Is there a reason why we would only want to test this feature on x86?

shafik: Is there a reason why we would only want to test this feature on x86?
aprantlUnsubmitted
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Presumably because the input is X86 assembly. That said, would it be possible to test the feature without constructing a process, so we *can* test it everywhere?

aprantl: Presumably because the input is X86 assembly. That said, would it be possible to test the…
SouraVXAuthorUnsubmitted
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I tried, other ways also. Seems like this is bare minimum, We need to run the program to be able to expand macros. analogous behavior with GDB also.
If you've some better way in mind to test this. or where to put this. Please share.

SouraVX: I tried, other ways also. Seems like this is bare minimum, We need to run the program to be…
labathUnsubmitted
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It wouldn't be unreasonable to add some command to query active macro definitions at a given point in the program (similar to gdb's info macros command). In lldb, the best place to plug this into might be the "image lookup" command -- right now "image lookup --verbose --file a.cpp --line 10" will give you the function containing that line as well as all variables which are active at that point. It seems natural to also list the active macros too.

However, that would most likely require adding a new "macros" field to the SymbolContext class, which is a concept used throughout lldb, and so doing it may be fairly tricky and it may be better to create a separate command for this at first ("image dump macros"?)...

(also note that in the current form, this test will not only require x86, but also a linux (or at least elf) system)

labath: It wouldn't be unreasonable to add some command to query active macro definitions at a given…
# contains DWARFv5 DW_MACRO_define_strx/DW_MACRO_undef_strx forms
#
# RUN: %clang_host -gdwarf-5 %p/Inputs/dwarf5-macro.s -o %t
# RUN: %lldb -s %s %t 2>&1 | FileCheck %s
display FOO
display BAR
b main
run
# CHECK: Hook {{.*}} (expr -- FOO)
# CHECK-NEXT: {{.*}} 5
#
# CHECK: Hook {{.*}} (expr -- BAR)
# CHECK-NEXT: {{.*}} 6