[CodeExtractor] Only rewrite scope of labels that were not inlined

[fdeazeve]

Summary

dbg.labels that were inlined from other functions should have their
scope preserved upon outlining for the same reasons described in
D139669.

[fdeazeve]

Closed by rG79d59c3f3e8a
Accidentally pushed the commit without differential tag, my bad.

llvm/lib/Transforms/Utils/CodeExtractor.cpp

static void fixupDebugInfoPostExtraction(Function &OldFunc, Function &NewFunc,
   SmallDenseMap<DINode *, DINode *> RemappedMetadata;
   SmallVector<Instruction *, 4> DebugIntrinsicsToDelete;
   DenseMap<const MDNode *, MDNode *> Cache;
   for (Instruction &I : instructions(NewFunc)) {
     auto *DII = dyn_cast<DbgInfoIntrinsic>(&I);
     if (!DII)
       continue;
 
-    // Point the intrinsic to a fresh label within the new function.
+    // Point the intrinsic to a fresh label within the new function if the
+    // intrinsic was not inlined from some other function.
     if (auto *DLI = dyn_cast<DbgLabelInst>(&I)) {
+      if (DLI->getDebugLoc().getInlinedAt())
+        continue;
       DILabel *OldLabel = DLI->getLabel();
       DINode *&NewLabel = RemappedMetadata[OldLabel];
       if (!NewLabel)
         NewLabel = DILabel::get(Ctx, NewSP, OldLabel->getName(),
                                 OldLabel->getFile(), OldLabel->getLine());
       DLI->setArgOperand(0, MetadataAsValue::get(Ctx, NewLabel));
       continue;
     }

llvm/test/Transforms/HotColdSplit/split-out-dbg-label.ll

 ; RUN: opt -passes=hotcoldsplit -hotcoldsplit-threshold=0 -S < %s | FileCheck %s
 
 ; When an llvm.dbg.label intrinsic is extracted into a new function, make sure
 ; that its metadata argument is a DILabel that points to a scope within the new
 ; function.
 ;
 ; In this example, the label "bye" points to the scope for @foo before
 ; splitting, and should point to the scope for @foo.cold.1 after splitting.
 
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.14.0"
 
 ; CHECK-LABEL: define {{.*}}@foo.cold.1
 ; CHECK: llvm.dbg.label(metadata [[LABEL:![0-9]+]]), !dbg [[LINE:![0-9]+]]
+; CHECK: llvm.dbg.label(metadata [[LABEL_IN_INLINE_ME:![0-9]+]]), !dbg [[LINE2:![0-9]+]]
 
 ; CHECK: [[FILE:![0-9]+]] = !DIFile
+; CHECK: [[INLINE_ME_SCOPE:![0-9]+]] = distinct !DISubprogram(name: "inline_me"
 ; CHECK: [[SCOPE:![0-9]+]] = distinct !DISubprogram(name: "foo.cold.1"
 ; CHECK: [[LINE]] = !DILocation(line: 1, column: 1, scope: [[SCOPE]]
 ; CHECK: [[LABEL]] = !DILabel(scope: [[SCOPE]], name: "bye", file: [[FILE]], line: 28
+; CHECK: [[LABEL_IN_INLINE_ME]] = !DILabel(scope: [[INLINE_ME_SCOPE]], name: "label_in_@inline_me", file: [[FILE]], line: 29
+; CHECK: [[LINE2]] = !DILocation(line: 2, column: 2, scope: [[INLINE_ME_SCOPE]], inlinedAt: [[LINE]]
 
 define void @foo(i32 %arg1) !dbg !6 {
 entry:
   %var = add i32 0, 0, !dbg !11
   br i1 undef, label %if.then, label %if.end
 
 if.then:                                          ; preds = %entry
   ret void
 
 if.end:                                           ; preds = %entry
   call void @llvm.dbg.label(metadata !12), !dbg !11
+  call void @llvm.dbg.label(metadata !14), !dbg !15
   call void @sink()
   ret void
 }
 
 declare void @llvm.dbg.label(metadata)
 
 declare void @sink() cold
 
+define void @inline_me() !dbg !13 {
+  ret void
+}
+
 !llvm.dbg.cu = !{!0}
 !llvm.debugify = !{!3, !4}
 !llvm.module.flags = !{!5}
 
 !0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
 !1 = !DIFile(filename: "<stdin>", directory: "/")
 !2 = !{}
 !3 = !{i32 7}
 !4 = !{i32 1}
 !5 = !{i32 2, !"Debug Info Version", i32 3}
 !6 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: null, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, retainedNodes: !8)
 !7 = !DISubroutineType(types: !2)
 !8 = !{!9}
 !9 = !DILocalVariable(name: "1", scope: !6, file: !1, line: 1, type: !10)
 !10 = !DIBasicType(name: "ty32", size: 32, encoding: DW_ATE_unsigned)
 !11 = !DILocation(line: 1, column: 1, scope: !6)
 !12 = !DILabel(scope: !6, name: "bye", file: !1, line: 28)
+!13 = distinct !DISubprogram(name: "inline_me", linkageName: "inline_me", scope: null, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, retainedNodes: !8)
+!14 = !DILabel(scope: !13, name: "label_in_@inline_me", file: !1, line: 29)
+!15 = !DILocation(line: 2, column: 2, scope: !13, inlinedAt: !11)