https://github.com/felipepiovezan created https://github.com/llvm/llvm-project/pull/78486
This allows us to query the AT_Name of a DIE without parsing the entire CU. Part of the ongoing effort to support IDX_Parent in accelerator tables [1]. [1]: https://discourse.llvm.org/t/rfc-improve-dwarf-5-debug-names-type-lookup-parsing-speed/74151/44 >From 0bfe58000b8d643efde8b84a6f80fc25dd48d48d Mon Sep 17 00:00:00 2001 From: Felipe de Azevedo Piovezan <fpiove...@apple.com> Date: Thu, 7 Dec 2023 11:26:52 -0800 Subject: [PATCH] [lldb][DWARFUnit] Implement PeekDIEName query This allows us to query the AT_Name of a DIE without parsing the entire CU. Part of the ongoing effort to support IDX_Parent in accelerator tables [1]. [1]: https://discourse.llvm.org/t/rfc-improve-dwarf-5-debug-names-type-lookup-parsing-speed/74151/44 --- .../SymbolFile/DWARF/DWARFDebugInfo.cpp | 7 +++ .../Plugins/SymbolFile/DWARF/DWARFDebugInfo.h | 5 ++ .../Plugins/SymbolFile/DWARF/DWARFUnit.cpp | 8 +++ .../Plugins/SymbolFile/DWARF/DWARFUnit.h | 5 ++ .../SymbolFile/DWARF/DWARFDIETest.cpp | 58 +++++++++++++++++++ 5 files changed, 83 insertions(+) diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp index 553b6a4c551d205..775b7a2e73f512f 100644 --- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp +++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp @@ -191,3 +191,10 @@ DWARFDebugInfo::GetDIE(const DIERef &die_ref) { return cu->GetNonSkeletonUnit().GetDIE(die_ref.die_offset()); return DWARFDIE(); // Not found } + +llvm::StringRef +DWARFDebugInfo::PeekDIEName(const DIERef &die_ref) { + if(DWARFUnit *cu = GetUnit(die_ref)) + return cu->GetNonSkeletonUnit().PeekDIEName(die_ref.die_offset()); + return llvm::StringRef(); +} diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.h index d5e48f312ea0e98..a8b5abc3beed2d0 100644 --- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.h +++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.h @@ -43,6 +43,11 @@ class DWARFDebugInfo { bool ContainsTypeUnits(); DWARFDIE GetDIE(const DIERef &die_ref); + /// Returns the AT_Name of this DIE, if it exists, without parsing the entire + /// compile unit. An empty is string is returned upon error or if the + /// attribute is not present. + llvm::StringRef PeekDIEName(const DIERef &die_ref); + enum { eDumpFlag_Verbose = (1 << 0), // Verbose dumping eDumpFlag_ShowForm = (1 << 1), // Show the DW_form type diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp index 0e2f4d45543bb53..7db279ed37d04aa 100644 --- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp +++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp @@ -663,6 +663,14 @@ DWARFUnit::GetDIE(dw_offset_t die_offset) { return DWARFDIE(); // Not found } +llvm::StringRef DWARFUnit::PeekDIEName(dw_offset_t die_offset) { + const DWARFDataExtractor &data = GetData(); + DWARFDebugInfoEntry die; + if (!die.Extract(data, this, &die_offset)) + return llvm::StringRef(); + return die.GetName(this); +} + DWARFUnit &DWARFUnit::GetNonSkeletonUnit() { ExtractUnitDIEIfNeeded(); if (m_dwo) diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h index 3f528e913d8cfab..bc225a52e1d0309 100644 --- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h +++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h @@ -187,6 +187,11 @@ class DWARFUnit : public UserID { DWARFDIE GetDIE(dw_offset_t die_offset); + /// Returns the AT_Name of the DIE at `die_offset`, if it exists, without + /// parsing the entire compile unit. An empty is string is returned upon + /// error or if the attribute is not present. + llvm::StringRef PeekDIEName(dw_offset_t die_offset); + DWARFUnit &GetNonSkeletonUnit(); static uint8_t GetAddressByteSize(const DWARFUnit *cu); diff --git a/lldb/unittests/SymbolFile/DWARF/DWARFDIETest.cpp b/lldb/unittests/SymbolFile/DWARF/DWARFDIETest.cpp index 8497855b2f3db59..074873b65bc8dd4 100644 --- a/lldb/unittests/SymbolFile/DWARF/DWARFDIETest.cpp +++ b/lldb/unittests/SymbolFile/DWARF/DWARFDIETest.cpp @@ -7,6 +7,7 @@ //===----------------------------------------------------------------------===// #include "Plugins/SymbolFile/DWARF/DWARFDIE.h" +#include "Plugins/SymbolFile/DWARF/DWARFDebugInfo.h" #include "TestingSupport/Symbol/YAMLModuleTester.h" #include "llvm/ADT/STLExtras.h" #include "gmock/gmock.h" @@ -104,3 +105,60 @@ TEST(DWARFDIETest, ChildIteration) { DWARFDIE no_children_die(unit, die_child0); EXPECT_TRUE(no_children_die.children().empty()); } + +TEST(DWARFDIETest, PeekName) { + const char *yamldata = R"( +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_EXEC + Machine: EM_386 +DWARF: + debug_str: + - 'NameType1' + - 'NameType2' + debug_abbrev: + - Table: + - Code: 0x00000001 + Tag: DW_TAG_compile_unit + Children: DW_CHILDREN_yes + Attributes: + - Attribute: DW_AT_language + Form: DW_FORM_data2 + - Code: 0x00000002 + Tag: DW_TAG_base_type + Children: DW_CHILDREN_no + Attributes: + - Attribute: DW_AT_name + Form: DW_FORM_strp + debug_info: + - Version: 4 + AddrSize: 8 + Entries: + - AbbrCode: 0x00000001 + Values: + - Value: 0x000000000000000C + - AbbrCode: 0x00000002 + Values: + - Value: 0x0000000000000000 # Name = NameType1 + - AbbrCode: 0x00000002 + Values: + - Value: 0x000000000000000a # Name = NameType2 + - AbbrCode: 0x00000000 +)"; + + YAMLModuleTester t(yamldata); + auto *symbol_file = + llvm::cast<SymbolFileDWARF>(t.GetModule()->GetSymbolFile()); + auto &debug_info = symbol_file->DebugInfo(); + + DIERef first_die(std::nullopt, DIERef::Section::DebugInfo, 11 /*FirstDIEOffset*/); + EXPECT_EQ(debug_info.PeekDIEName(first_die), ""); + + DIERef second_die(std::nullopt, DIERef::Section::DebugInfo, 14); + EXPECT_EQ(debug_info.PeekDIEName(second_die), "NameType1"); + + DIERef third_die(std::nullopt, DIERef::Section::DebugInfo, 19); + EXPECT_EQ(debug_info.PeekDIEName(third_die), "NameType2"); +} _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
