[DWARF] LLVM ERROR: Broken function found, while removing Debug Intrinsics.
Check that when SimplifyCFG is flattening a 'br', all their debug intrinsic instructions are removed, including any dbg.label referencing a label associated with the basic blocks being removed.
Differential Revision: https://reviews.llvm.org/D57444
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353511 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h
index 285666a..6032f65 100644
--- a/include/llvm/Transforms/Utils/Local.h
+++ b/include/llvm/Transforms/Utils/Local.h
@@ -467,8 +467,7 @@
/// \p DomBlock, by moving its instructions to the insertion point \p InsertPt.
///
/// The moved instructions receive the insertion point debug location values
-/// (DILocations) and their debug intrinsic instructions (dbg.values) are
-/// removed.
+/// (DILocations) and their debug intrinsic instructions are removed.
void hoistAllInstructionsInto(BasicBlock *DomBlock, Instruction *InsertPt,
BasicBlock *BB);
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index d9f6f6b..70812dc 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -2530,13 +2530,13 @@
BasicBlock *BB) {
// Since we are moving the instructions out of its basic block, we do not
// retain their original debug locations (DILocations) and debug intrinsic
- // instructions (dbg.values).
+ // instructions.
//
// Doing so would degrade the debugging experience and adversely affect the
// accuracy of profiling information.
//
// Currently, when hoisting the instructions, we take the following actions:
- // - Remove their dbg.values.
+ // - Remove their debug intrinsic instructions.
// - Set their debug locations to the values from the insertion point.
//
// As per PR39141 (comment #8), the more fundamental reason why the dbg.values
@@ -2554,7 +2554,7 @@
I->dropUnknownNonDebugMetadata();
if (I->isUsedByMetadata())
dropDebugUsers(*I);
- if (isa<DbgVariableIntrinsic>(I)) {
+ if (isa<DbgInfoIntrinsic>(I)) {
// Remove DbgInfo Intrinsics.
II = I->eraseFromParent();
continue;
diff --git a/test/CodeGen/X86/bbi-23595.ll b/test/CodeGen/X86/bbi-23595.ll
new file mode 100644
index 0000000..676a80b
--- /dev/null
+++ b/test/CodeGen/X86/bbi-23595.ll
@@ -0,0 +1,50 @@
+; RUN: opt < %s -S -simplifycfg | FileCheck %s
+
+; In 'simplifycfg', during the flattening of a 'br', the instructions for the
+; 'true' and 'false' parts, are moved out from their respective basic blocks.
+; Their original debug locations (DILocations) and debug intrinsic instructions
+; (dbg.values) are removed.
+; As those basic blocks are now empty, their associated labels are removed.
+;
+; For the given test case, the labels 'W' and 'cleanup4' are removed.
+; We're expecting the dbg.label associated with 'W' to disappear, because
+; the 'W' label was removed.
+
+; CHECK-LABEL: _Z7test_itv()
+; CHECK: entry:
+; CHECK-NEXT: %retval.0 = select i1 undef, i16 1, i16 0
+; CHECK-NEXT: ret i16 0
+
+define i16 @_Z7test_itv() {
+entry:
+ br label %sw.bb
+
+sw.bb: ; preds = %entry
+ br i1 undef, label %W, label %cleanup4
+
+W: ; preds = %sw.bb
+ call void @llvm.dbg.label(metadata !1), !dbg !8
+ br label %cleanup4
+
+cleanup4: ; preds = %W, %sw.bb
+ %retval.0 = phi i16 [ 1, %W ], [ 0, %sw.bb ]
+ ret i16 0
+}
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.label(metadata) #0
+
+attributes #0 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{}
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 2, !"Debug Info Version", i32 3}
+!1 = !DILabel(scope: !2, name: "W", file: !3, line: 47)
+!2 = distinct !DILexicalBlock(scope: !4, file: !3, line: 40, column: 3)
+!3 = !DIFile(filename: "foo.c", directory: "./")
+!4 = distinct !DISubprogram(name: "test_it", scope: !3, file: !3, line: 35, type: !5, scopeLine: 36, unit: !7)
+!5 = !DISubroutineType(types: !6)
+!6 = !{}
+!7 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
+!8 = !DILocation(line: 47, column: 2, scope: !2)
