[llvm] b38d77f - [SimplifyCFG] Remap rewritten debug intrinsic operands.
Vedant Kumar via llvm-commits
llvm-commits at lists.llvm.org
Fri May 8 11:10:34 PDT 2020
Author: Ricky Zhou
Date: 2020-05-08T11:10:25-07:00
New Revision: b38d77f185c53cb4bf108f0c29df1d6d7cfe13b4
URL: https://github.com/llvm/llvm-project/commit/b38d77f185c53cb4bf108f0c29df1d6d7cfe13b4
DIFF: https://github.com/llvm/llvm-project/commit/b38d77f185c53cb4bf108f0c29df1d6d7cfe13b4.diff
LOG: [SimplifyCFG] Remap rewritten debug intrinsic operands.
FoldBranchToCommonDest clones instructions to a different basic block,
but handles debug intrinsics in a separate path. Previously, when
cloning debug intrinsics, their operands were not updated to reference
the correct cloned values. As a result, we would emit debug.value
intrinsics with broken operand references which are discarded in later
passes. This leads to incorrect debuginfo that reports incorrect values
for variables.
Fix this by remapping debug intrinsic operands when cloning them.
Fixes https://bugs.llvm.org/show_bug.cgi?id=45667.
Differential Revision: https://reviews.llvm.org/D79602
Added:
llvm/test/DebugInfo/simplify-cfg-preserve-dbg-values.ll
Modified:
llvm/lib/Transforms/Utils/SimplifyCFG.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 2b82b23142e2..1fea5415aa8c 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -2898,9 +2898,14 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, MemorySSAUpdater *MSSAU,
// could replace PBI's branch probabilities with BI's.
// Copy any debug value intrinsics into the end of PredBlock.
- for (Instruction &I : *BB)
- if (isa<DbgInfoIntrinsic>(I))
- I.clone()->insertBefore(PBI);
+ for (Instruction &I : *BB) {
+ if (isa<DbgInfoIntrinsic>(I)) {
+ Instruction *NewI = I.clone();
+ RemapInstruction(NewI, VMap,
+ RF_NoModuleLevelChanges | RF_IgnoreMissingLocals);
+ NewI->insertBefore(PBI);
+ }
+ }
return true;
}
diff --git a/llvm/test/DebugInfo/simplify-cfg-preserve-dbg-values.ll b/llvm/test/DebugInfo/simplify-cfg-preserve-dbg-values.ll
new file mode 100644
index 000000000000..f708c66681d1
--- /dev/null
+++ b/llvm/test/DebugInfo/simplify-cfg-preserve-dbg-values.ll
@@ -0,0 +1,134 @@
+; RUN: opt %s -simplifycfg -verify -S -o - | FileCheck %s
+;
+; Verify that SimplifyCFG does not invalidate operands for
+; llvm.dbg.value intrinsics.
+;
+; Reduced from the following example, compiled with
+; -O1 -g -fno-exceptions -fno-discard-value-names:
+;
+; void test() {
+; bool a = false;
+; bool b = false;
+; bool c = false;
+; [&a, &b, &c] { b = true; }();
+;
+; if (a || b || c) {
+; __builtin_debugtrap();
+; }
+; }
+
+; CHECK: _Z4testv
+; CHECK-NOT: llvm.dbg.value(metadata !
+; CHECK: ret void
+
+%class.anon = type { i8*, i8*, i8* }
+
+; Function Attrs: nounwind uwtable
+define dso_local void @_Z4testv() local_unnamed_addr !dbg !7 {
+entry:
+ %a = alloca i8, align 1
+ %b = alloca i8, align 1
+ %c = alloca i8, align 1
+ %ref.tmp = alloca %class.anon, align 8
+ call void @llvm.dbg.value(metadata i8* %a, metadata !12, metadata !DIExpression(DW_OP_deref)), !dbg !16
+ call void @llvm.dbg.value(metadata i8 0, metadata !12, metadata !DIExpression()), !dbg !16
+ store i8 0, i8* %a, align 1, !dbg !16
+ call void @llvm.dbg.value(metadata i8* %b, metadata !14, metadata !DIExpression(DW_OP_deref)), !dbg !16
+ call void @llvm.dbg.value(metadata i8 0, metadata !14, metadata !DIExpression()), !dbg !16
+ store i8 0, i8* %b, align 1, !dbg !16
+ call void @llvm.dbg.value(metadata i8* %c, metadata !15, metadata !DIExpression(DW_OP_deref)), !dbg !16
+ call void @llvm.dbg.value(metadata i8 0, metadata !15, metadata !DIExpression()), !dbg !16
+ store i8 0, i8* %c, align 1, !dbg !16
+ %0 = bitcast %class.anon* %ref.tmp to i8*, !dbg !16
+ %1 = getelementptr inbounds %class.anon, %class.anon* %ref.tmp, i64 0, i32 0, !dbg !16
+ store i8* %a, i8** %1, align 8, !dbg !16
+ %2 = getelementptr inbounds %class.anon, %class.anon* %ref.tmp, i64 0, i32 1, !dbg !16
+ store i8* %b, i8** %2, align 8, !dbg !16
+ %3 = getelementptr inbounds %class.anon, %class.anon* %ref.tmp, i64 0, i32 2, !dbg !16
+ store i8* %c, i8** %3, align 8, !dbg !16
+ call fastcc void @"_ZZ4testvENK3$_0clEv"(%class.anon* nonnull %ref.tmp), !dbg !16
+ %4 = load i8, i8* %a, align 1, !dbg !17
+ call void @llvm.dbg.value(metadata i8 %4, metadata !12, metadata !DIExpression()), !dbg !16
+ %tobool = icmp eq i8 %4, 0, !dbg !17
+ br i1 %tobool, label %lor.lhs.false, label %if.then, !dbg !17
+
+lor.lhs.false: ; preds = %entry
+ %5 = load i8, i8* %b, align 1, !dbg !17
+ call void @llvm.dbg.value(metadata i8 %5, metadata !14, metadata !DIExpression()), !dbg !16
+ %tobool1 = icmp eq i8 %5, 0, !dbg !17
+ br i1 %tobool1, label %lor.lhs.false2, label %if.then, !dbg !17
+
+lor.lhs.false2: ; preds = %lor.lhs.false
+ %6 = load i8, i8* %c, align 1, !dbg !17
+ call void @llvm.dbg.value(metadata i8 %6, metadata !15, metadata !DIExpression()), !dbg !16
+ %tobool3 = icmp eq i8 %6, 0, !dbg !17
+ br i1 %tobool3, label %if.end, label %if.then, !dbg !16
+
+if.then: ; preds = %lor.lhs.false2, %lor.lhs.false, %entry
+ call void @llvm.debugtrap(), !dbg !19
+ br label %if.end, !dbg !19
+
+if.end: ; preds = %lor.lhs.false2, %if.then
+ call void @llvm.dbg.value(metadata i8* %c, metadata !15, metadata !DIExpression(DW_OP_deref)), !dbg !16
+ call void @llvm.dbg.value(metadata i8* %b, metadata !14, metadata !DIExpression(DW_OP_deref)), !dbg !16
+ call void @llvm.dbg.value(metadata i8* %a, metadata !12, metadata !DIExpression(DW_OP_deref)), !dbg !16
+ ret void, !dbg !16
+}
+
+; Function Attrs: inlinehint nounwind uwtable
+define internal fastcc void @"_ZZ4testvENK3$_0clEv"(%class.anon* %this) unnamed_addr align 2 !dbg !21 {
+entry:
+ call void @llvm.dbg.value(metadata %class.anon* %this, metadata !34, metadata !DIExpression()), !dbg !36
+ %0 = getelementptr inbounds %class.anon, %class.anon* %this, i32 0, i32 1, !dbg !36
+ %1 = load i8*, i8** %0, align 8, !dbg !36
+ store i8 1, i8* %1, align 1, !dbg !36
+ ret void, !dbg !36
+}
+
+; Function Attrs: nounwind
+declare void @llvm.debugtrap()
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.1-4 (tags/RELEASE_801/final)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.cc", directory: "/dir")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.1-4 (tags/RELEASE_801/final)"}
+!7 = distinct !DISubprogram(name: "test", linkageName: "_Z4testv", scope: !8, file: !8, line: 1, type: !9, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11)
+!8 = !DIFile(filename: "test.cc", directory: "/dir")
+!9 = !DISubroutineType(types: !10)
+!10 = !{null}
+!11 = !{!12, !14, !15}
+!12 = !DILocalVariable(name: "a", scope: !7, file: !8, line: 2, type: !13)
+!13 = !DIBasicType(name: "bool", size: 8, encoding: DW_ATE_boolean)
+!14 = !DILocalVariable(name: "b", scope: !7, file: !8, line: 3, type: !13)
+!15 = !DILocalVariable(name: "c", scope: !7, file: !8, line: 4, type: !13)
+!16 = !DILocation(line: 2, scope: !7)
+!17 = !DILocation(line: 7, scope: !18)
+!18 = distinct !DILexicalBlock(scope: !7, file: !8, line: 7)
+!19 = !DILocation(line: 8, scope: !20)
+!20 = distinct !DILexicalBlock(scope: !18, file: !8, line: 7)
+!21 = distinct !DISubprogram(name: "operator()", linkageName: "_ZZ4testvENK3$_0clEv", scope: !22, file: !8, line: 5, type: !28, scopeLine: 5, flags: DIFlagPrototyped, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, declaration: !32, retainedNodes: !33)
+!22 = distinct !DICompositeType(tag: DW_TAG_class_type, scope: !7, file: !8, line: 5, size: 192, flags: DIFlagTypePassByValue, elements: !23)
+!23 = !{!24, !26, !27}
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !22, file: !8, line: 5, baseType: !25, size: 64)
+!25 = !DIDerivedType(tag: DW_TAG_reference_type, baseType: !13, size: 64)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !22, file: !8, line: 5, baseType: !25, size: 64, offset: 64)
+!27 = !DIDerivedType(tag: DW_TAG_member, name: "c", scope: !22, file: !8, line: 5, baseType: !25, size: 64, offset: 128)
+!28 = !DISubroutineType(types: !29)
+!29 = !{null, !30}
+!30 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !31, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
+!31 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !22)
+!32 = !DISubprogram(name: "operator()", scope: !22, file: !8, line: 5, type: !28, scopeLine: 5, flags: DIFlagPublic | DIFlagPrototyped, spFlags: DISPFlagOptimized)
+!33 = !{!34}
+!34 = !DILocalVariable(name: "this", arg: 1, scope: !21, type: !35, flags: DIFlagArtificial | DIFlagObjectPointer)
+!35 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !31, size: 64)
+!36 = !DILocation(line: 0, scope: !21)
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