Index: llvm/trunk/include/llvm/IR/DIBuilder.h =================================================================== --- llvm/trunk/include/llvm/IR/DIBuilder.h +++ llvm/trunk/include/llvm/IR/DIBuilder.h @@ -757,12 +757,12 @@ const DILocation *DL, Instruction *InsertBefore); - /// Replace the vtable holder in the given composite type. + /// Replace the vtable holder in the given type. /// /// If this creates a self reference, it may orphan some unresolved cycles /// in the operands of \c T, so \a DIBuilder needs to track that. void replaceVTableHolder(DICompositeType *&T, - DICompositeType *VTableHolder); + DIType *VTableHolder); /// Replace arrays on a composite type. /// Index: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp =================================================================== --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp @@ -960,8 +960,9 @@ // This is outside the DWARF spec, but GDB expects a DW_AT_containing_type // inside C++ composite types to point to the base class with the vtable. - if (auto *ContainingType = - dyn_cast_or_null(resolve(CTy->getVTableHolder()))) + // Rust uses DW_AT_containing_type to link a vtable to the type + // for which it was created. + if (auto *ContainingType = resolve(CTy->getVTableHolder())) addDIEEntry(Buffer, dwarf::DW_AT_containing_type, *getOrCreateTypeDIE(ContainingType)); Index: llvm/trunk/lib/IR/DIBuilder.cpp =================================================================== --- llvm/trunk/lib/IR/DIBuilder.cpp +++ llvm/trunk/lib/IR/DIBuilder.cpp @@ -874,7 +874,7 @@ } void DIBuilder::replaceVTableHolder(DICompositeType *&T, - DICompositeType *VTableHolder) { + DIType *VTableHolder) { { TypedTrackingMDRef N(T); N->replaceVTableHolder(VTableHolder); Index: llvm/trunk/test/DebugInfo/Generic/containing-type-extension-rust.ll =================================================================== --- llvm/trunk/test/DebugInfo/Generic/containing-type-extension-rust.ll +++ llvm/trunk/test/DebugInfo/Generic/containing-type-extension-rust.ll @@ -0,0 +1,125 @@ +; REQUIRES: object-emission + +; RUN: %llc_dwarf -O0 -filetype=obj < %s > %t +; RUN: llvm-dwarfdump -v -debug-info %t | FileCheck %s + +; Check that any type can have a vtable holder. +; CHECK: [[SP:.*]]: DW_TAG_structure_type +; CHECK-NOT: TAG +; CHECK: DW_AT_containing_type [DW_FORM_ref4] +; CHECK: DW_AT_name [DW_FORM_strp] {{.*}}= "vtable") + +; This was compiled using +; rustc -g --emit=llvm-ir t2.rs +; ... and then edited by hand, because rustc is using a somewhat older llvm. +; +; t2.rs is: +; +; // trait object test case +; +; pub trait T { +; } +; +; impl T for f64 { +; } +; +; pub fn main() { +; let tu = &23.0f64 as &T; +; } +; t2.rs ends here ^^^ + +; ModuleID = 't2.cgu-0.rs' +source_filename = "t2.cgu-0.rs" +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +@ref.0 = internal unnamed_addr constant double 2.300000e+01, align 8 +@vtable.1 = internal unnamed_addr constant { void (double*)*, i64, i64 } { void (double*)* @_ZN4core3ptr13drop_in_place17h2818a933abde117eE, i64 8, i64 8 }, align 8, !dbg !0 +@__rustc_debug_gdb_scripts_section__ = linkonce_odr unnamed_addr constant [34 x i8] c"\01gdb_load_rust_pretty_printers.py\00", section ".debug_gdb_scripts", align 1 + +; core::ptr::drop_in_place +; Function Attrs: uwtable +define internal void @_ZN4core3ptr13drop_in_place17h2818a933abde117eE(double*) unnamed_addr #0 !dbg !11 { +start: + %arg0 = alloca double* + store double* %0, double** %arg0 + call void @llvm.dbg.declare(metadata double** %arg0, metadata !20, metadata !22), !dbg !23 + ret void, !dbg !24 +} + +; t2::main +; Function Attrs: uwtable +define internal void @_ZN2t24main17h6319e6ac7de3a097E() unnamed_addr #0 !dbg !25 { +start: + %tu = alloca { i8*, void (i8*)** } + call void @llvm.dbg.declare(metadata { i8*, void (i8*)** }* %tu, metadata !29, metadata !22), !dbg !37 + %0 = getelementptr inbounds { i8*, void (i8*)** }, { i8*, void (i8*)** }* %tu, i32 0, i32 0, !dbg !37 + store i8* bitcast (double* @ref.0 to i8*), i8** %0, !dbg !37 + %1 = getelementptr inbounds { i8*, void (i8*)** }, { i8*, void (i8*)** }* %tu, i32 0, i32 1, !dbg !37 + store void (i8*)** bitcast ({ void (double*)*, i64, i64 }* @vtable.1 to void (i8*)**), void (i8*)*** %1, !dbg !37 + ret void, !dbg !38 +} + +; Function Attrs: nounwind readnone +declare void @llvm.dbg.declare(metadata, metadata, metadata) #1 + +define i32 @main(i32, i8**) unnamed_addr #2 { +top: + %2 = load volatile i8, i8* getelementptr inbounds ([34 x i8], [34 x i8]* @__rustc_debug_gdb_scripts_section__, i32 0, i32 0), align 1 + %3 = sext i32 %0 to i64 +; call std::rt::lang_start + %4 = call i64 @_ZN3std2rt10lang_start17h2626caf1112a00beE(void ()* @_ZN2t24main17h6319e6ac7de3a097E, i64 %3, i8** %1) + %5 = trunc i64 %4 to i32 + ret i32 %5 +} + +; std::rt::lang_start +declare i64 @_ZN3std2rt10lang_start17h2626caf1112a00beE(void ()*, i64, i8**) unnamed_addr #3 + +attributes #0 = { uwtable "no-frame-pointer-elim"="true" "probe-stack"="__rust_probestack" } +attributes #1 = { nounwind readnone } +attributes #2 = { "no-frame-pointer-elim"="true" } +attributes #3 = { "no-frame-pointer-elim"="true" "probe-stack"="__rust_probestack" } + +!llvm.module.flags = !{!6, !7} +!llvm.dbg.cu = !{!8} + +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!1 = distinct !DIGlobalVariable(name: "vtable", scope: null, file: !2, type: !3, isLocal: true, isDefinition: true) +!2 = !DIFile(filename: "", directory: "") +!3 = !DICompositeType(tag: DW_TAG_structure_type, name: "vtable", file: !2, size: 64, align: 64, flags: DIFlagArtificial, elements: !4, vtableHolder: !5, identifier: "vtable") +!4 = !{} +!5 = !DIBasicType(name: "f64", size: 64, encoding: DW_ATE_float) +!6 = !{i32 1, !"PIE Level", i32 2} +!7 = !{i32 2, !"Debug Info Version", i32 3} +!8 = distinct !DICompileUnit(language: DW_LANG_Rust, file: !9, producer: "clang LLVM (rustc version 1.22.0-dev)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !10) +!9 = !DIFile(filename: "t2.rs", directory: "/home/tromey/Rust") +!10 = !{!0} +!11 = distinct !DISubprogram(name: "drop_in_place", linkageName: "_ZN4core3ptr18drop_in_placeE", scope: !13, file: !12, line: 59, type: !15, isLocal: false, isDefinition: true, scopeLine: 59, flags: DIFlagPrototyped, isOptimized: false, unit: !8, templateParams: !18, variables: !4) +!12 = !DIFile(filename: "/home/tromey/Rust/rust/src/libcore/ptr.rs", directory: "") +!13 = !DINamespace(name: "ptr", scope: !14) +!14 = !DINamespace(name: "core", scope: null) +!15 = !DISubroutineType(types: !16) +!16 = !{null, !17} +!17 = !DIDerivedType(tag: DW_TAG_pointer_type, name: "*mut f64", baseType: !5, size: 64, align: 64) +!18 = !{!19} +!19 = !DITemplateTypeParameter(name: "T", type: !5) +!20 = !DILocalVariable(arg: 1, scope: !11, file: !21, line: 1, type: !17) +!21 = !DIFile(filename: "t2.rs", directory: "") +!22 = !DIExpression() +!23 = !DILocation(line: 1, scope: !11) +!24 = !DILocation(line: 59, scope: !11) +!25 = distinct !DISubprogram(name: "main", linkageName: "_ZN2t24mainE", scope: !26, file: !9, line: 9, type: !27, isLocal: true, isDefinition: true, scopeLine: 9, flags: DIFlagPrototyped | DIFlagMainSubprogram, isOptimized: false, unit: !8, templateParams: !4, variables: !4) +!26 = !DINamespace(name: "t2", scope: null) +!27 = !DISubroutineType(types: !28) +!28 = !{null} +!29 = !DILocalVariable(name: "tu", scope: !30, file: !9, line: 10, type: !31, align: 8) +!30 = distinct !DILexicalBlock(scope: !25, file: !9, line: 10, column: 4) +!31 = !DICompositeType(tag: DW_TAG_structure_type, name: "&T", scope: !26, file: !2, size: 128, align: 64, elements: !32, identifier: "b9f642b757d8ad3984c1e721e3ce6016d14d9322") +!32 = !{!33, !36} +!33 = !DIDerivedType(tag: DW_TAG_member, name: "pointer", scope: !31, file: !2, baseType: !34, size: 64, align: 64, flags: DIFlagArtificial) +!34 = !DIDerivedType(tag: DW_TAG_pointer_type, name: "*const u8", baseType: !35, size: 64, align: 64) +!35 = !DIBasicType(name: "u8", size: 8, encoding: DW_ATE_unsigned) +!36 = !DIDerivedType(tag: DW_TAG_member, name: "vtable", scope: !31, file: !2, baseType: !34, size: 64, align: 64, offset: 64, flags: DIFlagArtificial) +!37 = !DILocation(line: 10, scope: !30) +!38 = !DILocation(line: 11, scope: !25) Index: llvm/trunk/test/DebugInfo/Generic/containing-type-extension.ll =================================================================== --- llvm/trunk/test/DebugInfo/Generic/containing-type-extension.ll +++ llvm/trunk/test/DebugInfo/Generic/containing-type-extension.ll @@ -0,0 +1,39 @@ +; REQUIRES: object-emission + +; RUN: %llc_dwarf -O0 -filetype=obj < %s > %t +; RUN: llvm-dwarfdump -v -debug-info %t | FileCheck %s + +; Check that any type can have a vtable holder. +; CHECK: [[SP:.*]]: DW_TAG_structure_type +; CHECK-NOT: TAG +; CHECK: DW_AT_containing_type [DW_FORM_ref4] +; CHECK: DW_AT_name [DW_FORM_strp] {{.*}}= "vtable") + +; The code doesn't actually matter. +define i32 @main() #0 !dbg !4 { +entry: + %retval = alloca i32, align 4 + store i32 0, i32* %retval + ret i32 0, !dbg !10 +} + +attributes #0 = { nounwind uwtable } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!9, !11} + +!0 = distinct !DICompileUnit(language: DW_LANG_Rust, producer: "clang version 3.4 (trunk 185475)", isOptimized: false, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, globals: !15, imports: !2) +!1 = !DIFile(filename: "CodeGen/dwarf-version.c", directory: "test") +!2 = !{} +!4 = distinct !DISubprogram(name: "main", line: 6, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped | DIFlagMainSubprogram, isOptimized: false, unit: !0, scopeLine: 6, file: !1, scope: !5, type: !6, variables: !2) +!5 = !DIFile(filename: "CodeGen/dwarf-version.c", directory: "test") +!6 = !DISubroutineType(types: !7) +!7 = !{!8} +!8 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed) +!9 = !{i32 2, !"Dwarf Version", i32 4} +!10 = !DILocation(line: 7, scope: !4) +!11 = !{i32 1, !"Debug Info Version", i32 3} +!12 = !DICompositeType(tag: DW_TAG_structure_type, name: "vtable", size: 8, align: 8, elements: !2, identifier: "vtable", vtableHolder: !8) +!13 = !DIGlobalVariableExpression(var: !14, expr: !DIExpression()) +!14 = !DIGlobalVariable(name: "vtable", linkageName: "vtable", scope: null, file: !1, line: 1, type: !12, isLocal: true, isDefinition: true) +!15 = !{!13} Index: llvm/trunk/unittests/IR/MetadataTest.cpp =================================================================== --- llvm/trunk/unittests/IR/MetadataTest.cpp +++ llvm/trunk/unittests/IR/MetadataTest.cpp @@ -1314,6 +1314,11 @@ EXPECT_EQ(nullptr, N->getVTableHolder()); N->replaceVTableHolder(VTableHolder); EXPECT_EQ(VTableHolder, N->getVTableHolder()); + // As an extension, the containing type can be anything. This is + // used by Rust to associate vtables with their concrete type. + DIType *BasicType = getBasicType("basic"); + N->replaceVTableHolder(BasicType); + EXPECT_EQ(BasicType, N->getVTableHolder()); N->replaceVTableHolder(nullptr); EXPECT_EQ(nullptr, N->getVTableHolder());