"fragment is larger than or outside of variable" error in Windows selfhost build

[gregbedwell]

Bugzilla Link	35447
Resolution	FIXED
Resolved on	Nov 29, 2017 08:26
Version	trunk
OS	Windows NT
CC	@adrian-prantl,@rnk,@rgal

Extended Description

The fix from Bug 35416 resolved that issue, however it seems that the file in question (lib/Support/FileOutputBuffer.cpp) is still refusing to compile with TOT clang.

Here's another source-level reduced testcase (it only looks subtly different to the one from Bug 35416, so hopefully the fix is too):

$ type 1.cpp // ====================================================== struct A { int _Myval2; A() : _Myval2() {} }; struct B { double buffer[]; }; struct C { C(int) {} A _Mypair; }; int getPtr(); struct D { C takePayload() { C Tmp(getPtr()); return Tmp; } } Dd; void operator new(size_t, void ); struct F { F(D Err) : HasError() { C e = (C )(ErrorStorage.buffer); new (e) C(Err.takePayload()); } B ErrorStorage; bool HasError; }; F fn2() { return Dd; } void fn3() { fn2(); } // ======================================================

$ clang.exe -target x86_64-windows-pc-msvc -c -w -g -O2 1.cpp fragment is larger than or outside of variable call void @​llvm.dbg.value(metadata i8 0, metadata !​72, metadata !DIExpression(DW_OP_LLVM_fragment, 64, 8)), !dbg !​105 !​72 = !DILocalVariable(name: "Tmp", scope: !​70, file: !​3, line: 16, type: !​7) fragment is larger than or outside of variable call void @​llvm.dbg.value(metadata i8 0, metadata !​72, metadata !DIExpression(DW_OP_LLVM_fragment, 64, 8)), !dbg !​105 !​72 = !DILocalVariable(name: "Tmp", scope: !​70, file: !​3, line: 16, type: !​7) fatal error: error in backend: Broken module found, compilation aborted! clang.exe: error: clang frontend command failed with exit code 70 (use -v to see invocation) clang version 6.0.0 (trunk 319007) (llvm/trunk 319177) Target: x86_64-pc-windows-msvc Thread model: posix InstalledDir: C:\work\public-git\upstream-llvm\build-vs2015-ps4-master\Release\bin clang.exe: note: diagnostic msg: PLEASE submit a bug report to http://llvm.org/bugs/ and include the crash backtrace, preprocessed source, and associated run script. clang.exe: note: diagnostic msg:

---

[009b8ea0-6754-41bc-becf-d830f82bdd65]

mentioned in issue llvm/llvm-bugzilla-archive#37222

[gregbedwell]

Ought to be fixed in r319230.

Thanks! Looks like FileOutputBuffer.cpp is compiling now with that fix in.

[adrian-prantl]

Ought to be fixed in r319230.

[adrian-prantl]

It looks like the right solution is - similar in sprit to the other bug - to not generate a new dbg.value when for a piece of the alloca that is outside of the variable (since the alloca may be larger than the variable).

[adrian-prantl]

reduced testcase for opt -sroa:

; ModuleID = '' source_filename = "test.ll"

%struct.F = type { %struct.B, i8 } %struct.B = type { [0 x double], [8 x i8] }

define void @"\01?fn3@@YAXXZ"() local_unnamed_addr !dbg !​31 { entry: %tmp = alloca %struct.F, align 8 %0 = bitcast %struct.F %tmp to i8, !dbg !​34 call void @​llvm.lifetime.start.p0i8(i64 16, i8 %0), !dbg !​34 call void @​llvm.dbg.declare(metadata %struct.F %tmp, metadata !​35, metadata !DIExpression()), !dbg !​40 %_Myval2.i.i.i.i.i = bitcast %struct.F %tmp to i32, !dbg !​71 store i32 0, i32* %_Myval2.i.i.i.i.i, align 8, !dbg !​71 ret void, !dbg !​82 }

; Function Attrs: argmemonly nounwind declare void @​llvm.lifetime.start.p0i8(i64, i8* nocapture) #​0

; Function Attrs: nounwind readnone speculatable declare void @​llvm.dbg.declare(metadata, metadata, metadata) #​1

attributes #​0 = { argmemonly nounwind } attributes #​1 = { nounwind readnone speculatable }

!llvm.dbg.cu = !{#0} !llvm.module.flags = !{#27, !​28, !​29, !​30}

!​0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !​1, producer: "clang version 6.0.0 (trunk 319178) (llvm/trunk 319187)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !​2, retainedTypes: !​2, globals: !​3) !​1 = !DIFile(filename: "/Data/radar/35723927/test.cpp", directory: "/Data/radar/35723927") !​2 = !{} !​3 = !{#4} !​4 = !DIGlobalVariableExpression(var: !​5, expr: !DIExpression()) !​5 = distinct !DIGlobalVariable(name: "Dd", linkageName: "\01?Dd@@3UD@@A", scope: !​0, file: !​1, line: 19, type: !​6, isLocal: false, isDefinition: true) !​6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "D", file: !​1, line: 14, size: 8, elements: !​7, identifier: ".?AUD@@") !​7 = !{#8} !​8 = !DISubprogram(name: "takePayload", linkageName: "\01?takePayload@D@@QEAA?AUC@@XZ", scope: !​6, file: !​1, line: 15, type: !​9, isLocal: false, isDefinition: false, scopeLine: 15, flags: DIFlagPrototyped, isOptimized: true) !​9 = !DISubroutineType(types: !​10) !​10 = !{#11, !​26} !​11 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "C", file: !​1, line: 9, size: 32, elements: !​12, identifier: ".?AUC@@") !​12 = !{#13, !​22} !​13 = !DIDerivedType(tag: DW_TAG_member, name: "_Mypair", scope: !​11, file: !​1, line: 11, baseType: !​14, size: 32) !​14 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "A", file: !​1, line: 2, size: 32, elements: !​15, identifier: ".?AUA@@") !​15 = !{#16, !​18} !​16 = !DIDerivedType(tag: DW_TAG_member, name: "_Myval2", scope: !​14, file: !​1, line: 3, baseType: !​17, size: 32) !​17 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) !​18 = !DISubprogram(name: "A", scope: !​14, file: !​1, line: 4, type: !​19, isLocal: false, isDefinition: false, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true) !​19 = !DISubroutineType(types: !​20) !​20 = !{null, !​21} !​21 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !​14, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer) !​22 = !DISubprogram(name: "C", scope: !​11, file: !​1, line: 10, type: !​23, isLocal: false, isDefinition: false, scopeLine: 10, flags: DIFlagPrototyped, isOptimized: true) !​23 = !DISubroutineType(types: !​24) !​24 = !{null, !​25, !​17} !​25 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !​11, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer) !​26 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !​6, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer) !​27 = !{i32 2, !"Dwarf Version", i32 4} !​28 = !{i32 2, !"Debug Info Version", i32 3} !​29 = !{i32 1, !"wchar_size", i32 2} !​30 = !{i32 7, !"PIC Level", i32 2} !​31 = distinct !DISubprogram(name: "fn3", linkageName: "\01?fn3@@YAXXZ", scope: !​1, file: !​1, line: 30, type: !​32, isLocal: false, isDefinition: true, scopeLine: 30, flags: DIFlagPrototyped, isOptimized: true, unit: !​0, variables: !​2) !​32 = !DISubroutineType(types: !​33) !​33 = !{null} !​34 = !DILocation(line: 30, column: 14, scope: !​31) !​35 = !DILocalVariable(name: "Tmp", scope: !​36, file: !​1, line: 16, type: !​11) !​36 = distinct !DISubprogram(name: "takePayload", linkageName: "\01?takePayload@D@@QEAA?AUC@@XZ", scope: !​6, file: !​1, line: 15, type: !​9, isLocal: false, isDefinition: true, scopeLine: 15, flags: DIFlagPrototyped, isOptimized: true, unit: !​0, declaration: !​8, variables: !​37) !​37 = !{#38, !​35} !​38 = !DILocalVariable(name: "this", arg: 1, scope: !​36, type: !​39, flags: DIFlagArtificial | DIFlagObjectPointer) !​39 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !​6, size: 64) !​40 = !DILocation(line: 16, column: 7, scope: !​36, inlinedAt: !​41) !​41 = distinct !DILocation(line: 24, column: 19, scope: !​42, inlinedAt: !​66) !​42 = distinct !DILexicalBlock(scope: !​43, file: !​1, line: 22, column: 25) !​43 = distinct !DISubprogram(name: "F", linkageName: "\01??0F@@QEAA@UD@@@Z", scope: !​44, file: !​1, line: 22, type: !​57, isLocal: false, isDefinition: true, scopeLine: 22, flags: DIFlagPrototyped, isOptimized: true, unit: !​0, declaration: !​56, variables: !​60) !​44 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "F", file: !​1, line: 21, size: 128, elements: !​45, identifier: ".?AUF@@") !​45 = !{#46, !​54, !​56} !​46 = !DIDerivedType(tag: DW_TAG_member, name: "ErrorStorage", scope: !​44, file: !​1, line: 26, baseType: !​47, size: 64) !​47 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "B", file: !​1, line: 6, size: 64, elements: !​48, identifier: ".?AUB@@") !​48 = !{#49} !​49 = !DIDerivedType(tag: DW_TAG_member, name: "buffer", scope: !​47, file: !​1, line: 7, baseType: !​50) !​50 = !DICompositeType(tag: DW_TAG_array_type, baseType: !​51, elements: !​52) !​51 = !DIBasicType(name: "double", size: 64, encoding: DW_ATE_float) !​52 = !{#53} !​53 = !DISubrange(count: -1) !​54 = !DIDerivedType(tag: DW_TAG_member, name: "HasError", scope: !​44, file: !​1, line: 27, baseType: !​55, size: 8, offset: 64) !​55 = !DIBasicType(name: "bool", size: 8, encoding: DW_ATE_boolean) !​56 = !DISubprogram(name: "F", scope: !​44, file: !​1, line: 22, type: !​57, isLocal: false, isDefinition: false, scopeLine: 22, flags: DIFlagPrototyped, isOptimized: true) !​57 = !DISubroutineType(types: !​58) !​58 = !{null, !​59, !​6} !​59 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !​44, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer) !​60 = !{#61, !​62, !​64} !​61 = !DILocalVariable(name: "Err", arg: 2, scope: !​43, file: !​1, line: 22, type: !​6) !​62 = !DILocalVariable(name: "this", arg: 1, scope: !​43, type: !​63, flags: DIFlagArtificial | DIFlagObjectPointer) !​63 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !​44, size: 64) !​64 = !DILocalVariable(name: "e", scope: !​42, file: !​1, line: 23, type: !​65) !​65 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !​11, size: 64) !​66 = distinct !DILocation(line: 29, column: 18, scope: !​67, inlinedAt: !​70) !​67 = distinct !DISubprogram(name: "fn2", linkageName: "\01?fn2@@YA?AUF@@XZ", scope: !​1, file: !​1, line: 29, type: !​68, isLocal: false, isDefinition: true, scopeLine: 29, flags: DIFlagPrototyped, isOptimized: true, unit: !​0, variables: !​2) !​68 = !DISubroutineType(types: !​69) !​69 = !{#44} !​70 = distinct !DILocation(line: 30, column: 14, scope: !​31) !​71 = !DILocation(line: 4, column: 9, scope: !​72, inlinedAt: !​76) !​72 = distinct !DISubprogram(name: "A", linkageName: "\01??0A@@QEAA@XZ", scope: !​14, file: !​1, line: 4, type: !​19, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, unit: !​0, declaration: !​18, variables: !​73) !​73 = !{#74} !​74 = !DILocalVariable(name: "this", arg: 1, scope: !​72, type: !​75, flags: DIFlagArtificial | DIFlagObjectPointer) !​75 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !​14, size: 64) !​76 = distinct !DILocation(line: 10, column: 3, scope: !​77, inlinedAt: !​81) !​77 = distinct !DISubprogram(name: "C", linkageName: "\01??0C@@QEAA@H@Z", scope: !​11, file: !​1, line: 10, type: !​23, isLocal: false, isDefinition: true, scopeLine: 10, flags: DIFlagPrototyped, isOptimized: true, unit: !​0, declaration: !​22, variables: !​78) !​78 = !{#79, !​80} !​79 = !DILocalVariable(arg: 2, scope: !​77, file: !​1, line: 10, type: !​17) !​80 = !DILocalVariable(name: "this", arg: 1, scope: !​77, type: !​65, flags: DIFlagArtificial | DIFlagObjectPointer) !​81 = distinct !DILocation(line: 16, column: 7, scope: !​36, inlinedAt: !​41) !​82 = !DILocation(line: 30, column: 21, scope: !​31)

[adrian-prantl]

It's again happening in SROA

IR Dump After Deduce function attributes ; Function Attrs: uwtable define void @"\01?fn3@@YAXXZ"() local_unnamed_addr #​0 !dbg !​34 { entry: %tmp = alloca %struct.F, align 8 %0 = bitcast %struct.F %tmp to i8, !dbg !​37 call void @​llvm.lifetime.start.p0i8(i64 16, i8 %0) #​5, !dbg !​37 call void @​llvm.dbg.value(metadata %struct.F %tmp, metadata !​38, metadata !DIExpression()), !dbg !​61 %HasError.i.i = getelementptr inbounds %struct.F, %struct.F %tmp, i64 0, i32 1, !dbg !​67 store i8 0, i8 %HasError.i.i, align 8, !dbg !​67, !tbaa !​68, !alias.scope !​72 call void @​llvm.dbg.value(metadata %struct.F %tmp, metadata !​58, metadata !DIExpression()), !dbg !​75 call void @​llvm.dbg.value(metadata %struct.D undef, metadata !​57, metadata !DIExpression()), !dbg !​76 call void @​llvm.dbg.value(metadata %struct.D undef, metadata !​77, metadata !DIExpression()), !dbg !​82 call void @​llvm.dbg.declare(metadata %struct.F %tmp, metadata !​80, metadata !DIExpression()), !dbg !​84 %call.i.i.i = call i32 @"\01?getPtr@@YAHXZ"(), !dbg !​85, !noalias !​86 call void @​llvm.dbg.value(metadata i32 %call.i.i.i, metadata !​89, metadata !DIExpression()), !dbg !​93 call void @​llvm.dbg.value(metadata %struct.F %tmp, metadata !​92, metadata !DIExpression()), !dbg !​95 call void @​llvm.dbg.value(metadata %struct.F %tmp, metadata !​96, metadata !DIExpression(DW_OP_stack_value)), !dbg !​100 %_Myval2.i.i.i.i.i = bitcast %struct.F %tmp to i32, !dbg !​102 store i32 0, i32 %_Myval2.i.i.i.i.i, align 8, !dbg !​102, !tbaa !​103, !alias.scope !​86 call void @​llvm.lifetime.end.p0i8(i64 16, i8 %0) #​5, !dbg !​37 ret void, !dbg !​106 } IR Dump After SROA ; Function Attrs: uwtable define void @"\01?fn3@@YAXXZ"() local_unnamed_addr #​0 !dbg !​117 { entry: call void @​llvm.dbg.declare(metadata !​4, metadata !​72, metadata !DIExpression()), !dbg !​120 call void @​llvm.dbg.declare(metadata !​4, metadata !​72, metadata !DIExpression(DW_OP_LLVM_fragment, 72, 56)), !dbg !​120 call void @​llvm.dbg.value(metadata %struct.F undef, metadata !​53, metadata !DIExpression()), !dbg !​124 call void @​llvm.dbg.value(metadata i8 0, metadata !​72, metadata !DIExpression(DW_OP_LLVM_fragment, 64, 8)), !dbg !​120 call void @​llvm.dbg.value(metadata %struct.F undef, metadata !​57, metadata !DIExpression()), !dbg !​125 call void @​llvm.dbg.value(metadata %struct.D undef, metadata !​56, metadata !DIExpression()), !dbg !​126 call void @​llvm.dbg.value(metadata %struct.D undef, metadata !​69, metadata !DIExpression()), !dbg !​127 %call.i.i.i = call i32 @"\01?getPtr@@YAHXZ"(), !dbg !​128, !noalias !​129 call void @​llvm.dbg.value(metadata i32 %call.i.i.i, metadata !​81, metadata !DIExpression()), !dbg !​134 call void @​llvm.dbg.value(metadata %struct.F undef, metadata !​84, metadata !DIExpression()), !dbg !​136 call void @​llvm.dbg.value(metadata %struct.F undef, metadata !​88, metadata !DIExpression(DW_OP_stack_value)), !dbg !​137 call void @​llvm.dbg.value(metadata i32 0, metadata !​72, metadata !DIExpression()), !dbg !​120 ret void, !dbg !​139 }

[adrian-prantl]

Thanks! I will try to fix this today.

[gregbedwell]

assigned to @adrian-prantl