From bcb8a119df210753c5f1a3ac346d49597fef0f51 Mon Sep 17 00:00:00 2001 From: Derek Schuff Date: Wed, 30 Sep 2020 11:55:12 -0700 Subject: [PATCH] [WebAssembly] Add support for DWARF type units Since Wasm comdat sections work similarly to ELF, we can use that mechanism to eliminate duplicate dwarf type information in the same way. Differential Revision: https://reviews.llvm.org/D88603 --- clang/lib/Driver/ToolChains/Clang.cpp | 2 +- clang/test/Driver/debug-options.c | 3 + llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 5 +- llvm/lib/MC/MCObjectFileInfo.cpp | 4 +- llvm/lib/MC/WasmObjectWriter.cpp | 3 - .../DebugInfo/WebAssembly/dwarf-headers.ll | 116 ++++++++++++++++++ 6 files changed, 126 insertions(+), 7 deletions(-) create mode 100644 llvm/test/DebugInfo/WebAssembly/dwarf-headers.ll diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 61e367bd835d..59cf34749bb4 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -3989,7 +3989,7 @@ static void RenderDebugOptions(const ToolChain &TC, const Driver &D, if (Args.hasFlag(options::OPT_fdebug_types_section, options::OPT_fno_debug_types_section, false)) { - if (!T.isOSBinFormatELF()) { + if (!(T.isOSBinFormatELF() || T.isOSBinFormatWasm())) { D.Diag(diag::err_drv_unsupported_opt_for_target) << Args.getLastArg(options::OPT_fdebug_types_section) ->getAsString(Args) diff --git a/clang/test/Driver/debug-options.c b/clang/test/Driver/debug-options.c index 1be976d9743a..bedc9d044a2c 100644 --- a/clang/test/Driver/debug-options.c +++ b/clang/test/Driver/debug-options.c @@ -214,6 +214,9 @@ // RUN: %clang -### -fdebug-types-section -fno-debug-types-section -target x86_64-unknown-linux %s 2>&1 \ // RUN: | FileCheck -check-prefix=NOFDTS %s // +// RUN: %clang -### -fdebug-types-section -target wasm32-unknown-unknown %s 2>&1 \ +// RUN: | FileCheck -check-prefix=FDTS %s +// // RUN: %clang -### -fdebug-types-section -target x86_64-apple-darwin %s 2>&1 \ // RUN: | FileCheck -check-prefix=FDTSE %s // diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp index e460402e7941..859956e6c3a5 100644 --- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -394,8 +394,9 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M) UseSectionsAsReferences = DwarfSectionsAsReferences == Enable; // Don't generate type units for unsupported object file formats. - GenerateTypeUnits = - A->TM.getTargetTriple().isOSBinFormatELF() && GenerateDwarfTypeUnits; + GenerateTypeUnits = (A->TM.getTargetTriple().isOSBinFormatELF() || + A->TM.getTargetTriple().isOSBinFormatWasm()) && + GenerateDwarfTypeUnits; TheAccelTableKind = computeAccelTableKind( DwarfVersion, GenerateTypeUnits, DebuggerTuning, A->TM.getTargetTriple()); diff --git a/llvm/lib/MC/MCObjectFileInfo.cpp b/llvm/lib/MC/MCObjectFileInfo.cpp index d8ea0a879f2b..fcae22c8ce2e 100644 --- a/llvm/lib/MC/MCObjectFileInfo.cpp +++ b/llvm/lib/MC/MCObjectFileInfo.cpp @@ -963,9 +963,11 @@ MCSection *MCObjectFileInfo::getDwarfComdatSection(const char *Name, case Triple::ELF: return Ctx->getELFSection(Name, ELF::SHT_PROGBITS, ELF::SHF_GROUP, 0, utostr(Hash)); + case Triple::Wasm: + return Ctx->getWasmSection(Name, SectionKind::getMetadata(), utostr(Hash), + MCContext::GenericSectionID); case Triple::MachO: case Triple::COFF: - case Triple::Wasm: case Triple::GOFF: case Triple::XCOFF: case Triple::UnknownObjectFormat: diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp index f81a83d1651c..2f1277eb8110 100644 --- a/llvm/lib/MC/WasmObjectWriter.cpp +++ b/llvm/lib/MC/WasmObjectWriter.cpp @@ -1378,9 +1378,6 @@ uint64_t WasmObjectWriter::writeOneObject(MCAssembler &Asm, MCSymbol *Begin = Sec.getBeginSymbol(); if (Begin) { WasmIndices[cast(Begin)] = CustomSections.size(); - if (SectionName != Begin->getName()) - report_fatal_error("section name and begin symbol should match: " + - Twine(SectionName)); } // Separate out the producers and target features sections diff --git a/llvm/test/DebugInfo/WebAssembly/dwarf-headers.ll b/llvm/test/DebugInfo/WebAssembly/dwarf-headers.ll new file mode 100644 index 000000000000..a35bbca2cd21 --- /dev/null +++ b/llvm/test/DebugInfo/WebAssembly/dwarf-headers.ll @@ -0,0 +1,116 @@ +; RUN: llc -dwarf-version=4 -generate-type-units \ +; RUN: -filetype=obj -O0 -mtriple=wasm32-unknown-unknown < %s \ +; RUN: | llvm-dwarfdump -v - | FileCheck %s --check-prefix=SINGLE-4 + +; RUN: llc -split-dwarf-file=foo.dwo -split-dwarf-output=%t.dwo \ +; RUN: -dwarf-version=4 -generate-type-units \ +; RUN: -filetype=obj -O0 -mtriple=wasm32-unknown-unknown < %s \ +; RUN: | llvm-dwarfdump -v - | FileCheck %s --check-prefix=O-4 +; RUN: llvm-dwarfdump -v %t.dwo | FileCheck %s --check-prefix=DWO-4 + +; TODO: enable testing for dwarf v5 +; RUN: llc -dwarf-version=5 -generate-type-units \ +; RUN: -filetype=obj -O0 -mtriple= < %s \ +; RUN: | llvm-dwarfdump -v - | FileCheck %s --check-prefix=SINGLE-5 + +; RUN: llc -split-dwarf-file=foo.dwo -split-dwarf-output=%t.dwo \ +; RUN: -dwarf-version=5 -generate-type-units \ +; RUN: -filetype=obj -O0 -mtriple= < %s \ +; RUN: | llvm-dwarfdump -v - | FileCheck %s --check-prefix=O-5 +; RUN: llvm-dwarfdump -v %t.dwo | FileCheck %s --check-prefix=DWO-5 + +; This test is derived from test/CodeGen/X86/dwarf-headers.ll + +; Looking for DWARF headers to be generated correctly. +; There are 8 variants with 5 formats: v4 CU, v4 TU, v5 normal/partial CU, +; v5 skeleton/split CU, v5 normal/split TU. Some v5 variants differ only +; in the unit_type code, and the skeleton/split CU differs from normal/partial +; by having one extra field (dwo_id). +; (v2 thru v4 CUs are all the same, and TUs were invented in v4, +; so we don't bother checking older versions.) + +; Test case built from: +;struct S { +; int s1; +;}; +; +;S s; + +; Verify the v4 non-split headers. +; Note that we check the exact offset of the DIEs because that tells us +; the length of the header. +; +; SINGLE-4: .debug_info contents: +; SINGLE-4: 0x00000000: Compile Unit: {{.*}} version = 0x0004, abbr_offset +; SINGLE-4: 0x0000000b: DW_TAG_compile_unit +; +; SINGLE-4: .debug_types contents: +; SINGLE-4: 0x00000000: Type Unit: {{.*}} version = 0x0004, abbr_offset +; SINGLE-4: 0x00000017: DW_TAG_type_unit + +; Verify the v4 split headers. +; +; O-4: .debug_info contents: +; O-4: 0x00000000: Compile Unit: {{.*}} version = 0x0004, abbr_offset +; O-4: 0x0000000b: DW_TAG_compile_unit +; +; DWO-4: .debug_info.dwo contents: +; DWO-4: 0x00000000: Compile Unit: {{.*}} version = 0x0004, abbr_offset +; DWO-4: 0x0000000b: DW_TAG_compile_unit +; +; DWO-4: .debug_types.dwo contents: +; DWO-4: 0x00000000: Type Unit: {{.*}} version = 0x0004, abbr_offset +; DWO-4: 0x00000017: DW_TAG_type_unit + +; Verify the v5 non-split headers. Type units come first. +; All .debug_info sections are reported in one go, but the offset resets for +; each new section. +; +; SINGLE-5: .debug_info contents: +; SINGLE-5: 0x00000000: Type Unit: {{.*}} version = 0x0005, unit_type = DW_UT_type, abbr_offset +; SINGLE-5: 0x00000018: DW_TAG_type_unit +; SINGLE-5-NOT: contents: +; SINGLE-5: 0x00000000: Compile Unit: {{.*}} version = 0x0005, unit_type = DW_UT_compile, abbr_offset +; SINGLE-5: 0x0000000c: DW_TAG_compile_unit + +; Verify the v5 split headers. +; +; O-5: .debug_info contents: +; O-5: 0x00000000: Compile Unit: {{.*}} version = 0x0005, unit_type = DW_UT_skeleton, abbr_offset +; O-5-SAME: DWO_id = 0xccd7e58ef8bf4aa6 +; O-5: 0x00000014: DW_TAG_skeleton_unit +; +; DWO-5: .debug_info.dwo contents: +; DWO-5: 0x00000000: Type Unit: {{.*}} version = 0x0005, unit_type = DW_UT_split_type, abbr_offset +; DWO-5: 0x00000018: DW_TAG_type_unit +; DWO-5: 0x00000033: Compile Unit: {{.*}} version = 0x0005, unit_type = DW_UT_split_compile, abbr_offset +; DWO-5-SAME: DWO_id = 0xccd7e58ef8bf4aa6 +; DWO-5: 0x00000047: DW_TAG_compile_unit + + +; ModuleID = 't.cpp' +source_filename = "t.cpp" +target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128" +target triple = "wasm32-unknown-unknown-wasm" + +%struct.S = type { i32 } + +@s = global %struct.S zeroinitializer, align 4, !dbg !0 + +!llvm.dbg.cu = !{!2} +!llvm.module.flags = !{!10, !11} +!llvm.ident = !{!12} + +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!1 = distinct !DIGlobalVariable(name: "s", scope: !2, file: !3, line: 5, type: !6, isLocal: false, isDefinition: true) +!2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "clang version 5.0.0 (trunk 295942)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5) +!3 = !DIFile(filename: "t.cpp", directory: "/home/probinson/projects/scratch") +!4 = !{} +!5 = !{!0} +!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "S", file: !3, line: 1, size: 32, elements: !7, identifier: "_ZTS1S") +!7 = !{!8} +!8 = !DIDerivedType(tag: DW_TAG_member, name: "s1", scope: !6, file: !3, line: 2, baseType: !9, size: 32) +!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!10 = !{i32 2, !"Dwarf Version", i32 4} +!11 = !{i32 2, !"Debug Info Version", i32 3} +!12 = !{!"clang version 5.0.0 (trunk 295942)"}