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[LLVM][DWARF] Fix accelerator table switching between CU and TU #77511

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merged 5 commits into from
Jan 12, 2024
Merged

[LLVM][DWARF] Fix accelerator table switching between CU and TU #77511

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5e6ee63
[LLVM][DWARF] Fix accelerator swtiching with TU re-use
ayermolo Jan 9, 2024
0cfe1ed
Fix second bug where we reset to cu table, while still processing TUs.
ayermolo Jan 9, 2024
dcd338b
updated test description
ayermolo Jan 9, 2024
c3fbd56
updated directory inside test
ayermolo Jan 9, 2024
c09e5b0
removed kind variable
ayermolo Jan 11, 2024
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73 changes: 73 additions & 0 deletions clang/test/CodeGen/debug-names-compound-type-units.ll
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@@ -0,0 +1,73 @@
; REQUIRES: asserts

;; Tests that we use correct accelerator table when processing nested TUs.
;; Assert is not triggered.
;; File1
;; struct Foo {
;; char f;
;; };
;; struct Foo2 {
;; char f;
;; Foo f1;
;; };
;; void fooFunc() {
;; Foo2 global2;
;; }
;; clang++ <file>.cpp -O0 -g2 -fdebug-types-section -gpubnames -S -emit-llvm -o <file>.ll

; RUN: llc -O0 -dwarf-version=5 -generate-type-units -filetype=obj < %s -o %t.o
; RUN: llvm-readelf --sections %t.o | FileCheck --check-prefix=OBJ %s

; OBJ: debug_names

; ModuleID = 'main.cpp'
source_filename = "main.cpp"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%struct.Foo2 = type { i8, %struct.Foo }
%struct.Foo = type { i8 }

; Function Attrs: mustprogress noinline nounwind optnone uwtable
define dso_local void @_Z7fooFuncv() #0 !dbg !10 {
entry:
%global2 = alloca %struct.Foo2, align 1
call void @llvm.dbg.declare(metadata ptr %global2, metadata !14, metadata !DIExpression()), !dbg !23
ret void, !dbg !24
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1

attributes #0 = { mustprogress noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!2, !3, !4, !5, !6, !7, !8}
!llvm.ident = !{!9}

!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 18.0.0git", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false)
!1 = !DIFile(filename: "main.cpp", directory: "/smallMultipleTUs", checksumkind: CSK_MD5, checksum: "70bff4d50322126f3d8ca4178afad376")
!2 = !{i32 7, !"Dwarf Version", i32 5}
!3 = !{i32 2, !"Debug Info Version", i32 3}
!4 = !{i32 1, !"wchar_size", i32 4}
!5 = !{i32 8, !"PIC Level", i32 2}
!6 = !{i32 7, !"PIE Level", i32 2}
!7 = !{i32 7, !"uwtable", i32 2}
!8 = !{i32 7, !"frame-pointer", i32 2}
!9 = !{!"clang version 18.0.0git"}
!10 = distinct !DISubprogram(name: "fooFunc", linkageName: "_Z7fooFuncv", scope: !1, file: !1, line: 9, type: !11, scopeLine: 9, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !13)
!11 = !DISubroutineType(types: !12)
!12 = !{null}
!13 = !{}
!14 = !DILocalVariable(name: "global2", scope: !10, file: !1, line: 10, type: !15)
!15 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo2", file: !1, line: 4, size: 16, flags: DIFlagTypePassByValue, elements: !16, identifier: "_ZTS4Foo2")
!16 = !{!17, !19}
!17 = !DIDerivedType(tag: DW_TAG_member, name: "f", scope: !15, file: !1, line: 5, baseType: !18, size: 8)
!18 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
!19 = !DIDerivedType(tag: DW_TAG_member, name: "f1", scope: !15, file: !1, line: 6, baseType: !20, size: 8, offset: 8)
!20 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo", file: !1, line: 1, size: 8, flags: DIFlagTypePassByValue, elements: !21, identifier: "_ZTS3Foo")
!21 = !{!22}
!22 = !DIDerivedType(tag: DW_TAG_member, name: "f", scope: !20, file: !1, line: 2, baseType: !18, size: 8)
!23 = !DILocation(line: 10, column: 6, scope: !10)
!24 = !DILocation(line: 11, column: 1, scope: !10)
58 changes: 58 additions & 0 deletions clang/test/CodeGen/thinlto-debug-names-tu-reuse.ll
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Original file line number Diff line number Diff line change
@@ -0,0 +1,58 @@
; REQUIRES: asserts

;; Tests that accelerator table switches correctly from TU to CU when a top level TU is re-used.
;; Assert is not triggered.
;; File1
;; struct Foo {
;; char fChar;
;; };
;; Foo fGlobal;
;; FIle2
;; struct Foo {
;; char fChar;
;; };
;; Foo fGlobal2;
;; clang++ <file>.cpp -O0 -g2 -fdebug-types-section -gpubnames -S -emit-llvm -o <file>.ll
;; llvm-link file1.ll file2.ll -S -o thinlto-debug-names-tu-reuse.ll

; RUN: llc -O0 -dwarf-version=5 -generate-type-units -filetype=obj < %s -o %t.o
; RUN: llvm-readelf --sections %t.o | FileCheck --check-prefix=OBJ %s

; OBJ: debug_names

; ModuleID = 'llvm-link'
source_filename = "llvm-link"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%struct.Foo = type { i8 }

@fGlobal = dso_local global %struct.Foo zeroinitializer, align 1, !dbg !0
@fGlobal2 = dso_local global %struct.Foo zeroinitializer, align 1, !dbg !9

!llvm.dbg.cu = !{!2, !11}
!llvm.ident = !{!14, !14}
!llvm.module.flags = !{!15, !16, !17, !18, !19, !20, !21}

!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
!1 = distinct !DIGlobalVariable(name: "fGlobal", scope: !2, file: !3, line: 5, type: !5, isLocal: false, isDefinition: true)
!2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !3, producer: "clang version 18.0.0git", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, splitDebugInlining: false)
!3 = !DIFile(filename: "main.cpp", directory: "/smallTUReuse", checksumkind: CSK_MD5, checksum: "4f1831504f0948b03880356fae49cb58")
!4 = !{!0}
!5 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo", file: !3, line: 2, size: 8, flags: DIFlagTypePassByValue, elements: !6, identifier: "_ZTS3Foo")
!6 = !{!7}
!7 = !DIDerivedType(tag: DW_TAG_member, name: "fChar", scope: !5, file: !3, line: 3, baseType: !8, size: 8)
!8 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
!9 = !DIGlobalVariableExpression(var: !10, expr: !DIExpression())
!10 = distinct !DIGlobalVariable(name: "fGlobal2", scope: !11, file: !12, line: 5, type: !5, isLocal: false, isDefinition: true)
!11 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !12, producer: "clang version 18.0.0git", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !13, splitDebugInlining: false)
!12 = !DIFile(filename: "helper.cpp", directory: "/smallTUReuse", checksumkind: CSK_MD5, checksum: "014145d46991fd1eb6a2192d382feb75")
!13 = !{!9}
!14 = !{!"clang version 18.0.0git"}
!15 = !{i32 7, !"Dwarf Version", i32 5}
!16 = !{i32 2, !"Debug Info Version", i32 3}
!17 = !{i32 1, !"wchar_size", i32 4}
!18 = !{i32 8, !"PIC Level", i32 2}
!19 = !{i32 7, !"PIE Level", i32 2}
!20 = !{i32 7, !"uwtable", i32 2}
!21 = !{i32 7, !"frame-pointer", i32 2}
12 changes: 10 additions & 2 deletions llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3448,7 +3448,6 @@ uint64_t DwarfDebug::makeTypeSignature(StringRef Identifier) {
void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
StringRef Identifier, DIE &RefDie,
const DICompositeType *CTy) {
setCurrentDWARF5AccelTable(DWARF5AccelTableKind::TU);
// Fast path if we're building some type units and one has already used the
// address pool we know we're going to throw away all this work anyway, so
// don't bother building dependent types.
Expand All @@ -3461,6 +3460,7 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
return;
}

setCurrentDWARF5AccelTable(DWARF5AccelTableKind::TU);
bool TopLevelType = TypeUnitsUnderConstruction.empty();
AddrPool.resetUsedFlag();

Expand Down Expand Up @@ -3549,9 +3549,9 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
AccelTypeUnitsDebugNames.convertDieToOffset();
AccelDebugNames.addTypeEntries(AccelTypeUnitsDebugNames);
AccelTypeUnitsDebugNames.clear();
setCurrentDWARF5AccelTable(DWARF5AccelTableKind::CU);
}
CU.addDIETypeSignature(RefDie, Signature);
setCurrentDWARF5AccelTable(DWARF5AccelTableKind::CU);
}

// Add the Name along with its companion DIE to the appropriate accelerator
Expand Down Expand Up @@ -3580,6 +3580,14 @@ void DwarfDebug::addAccelNameImpl(
break;
case AccelTableKind::Dwarf: {
DWARF5AccelTable &Current = getCurrentDWARF5AccelTable();
assert((&Current == &AccelTypeUnitsDebugNames) ||
((&Current == &AccelDebugNames) &&
(Unit.getUnitDie().getTag() != dwarf::DW_TAG_type_unit)) &&
"Kind is CU but TU is being processed.");
assert((&Current == &AccelDebugNames) ||
((&Current == &AccelTypeUnitsDebugNames) &&
(Unit.getUnitDie().getTag() == dwarf::DW_TAG_type_unit)) &&
"Kind is TU but CU is being processed.");
// The type unit can be discarded, so need to add references to final
// acceleration table once we know it's complete and we emit it.
Current.addName(Ref, Die, Unit.getUniqueID());
Expand Down