[llvm] r299107 - Teach stripNonLineTableDebugInfo() to remap DILocations in !llvm.loop nodes.

[Adrian Prantl via llvm-commits]

Author: adrian
Date: Thu Mar 30 15:10:56 2017
New Revision: 299107

URL: http://llvm.org/viewvc/llvm-project?rev=299107&view=rev
Log:
Teach stripNonLineTableDebugInfo() to remap DILocations in !llvm.loop nodes.

Added:
    llvm/trunk/test/Transforms/Util/strip-nonlinetable-debuginfo-loops.ll
Modified:
    llvm/trunk/lib/IR/DebugInfo.cpp

Modified: llvm/trunk/lib/IR/DebugInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/DebugInfo.cpp?rev=299107&r1=299106&r2=299107&view=diff
==============================================================================
--- llvm/trunk/lib/IR/DebugInfo.cpp (original)
+++ llvm/trunk/lib/IR/DebugInfo.cpp Thu Mar 30 15:10:56 2017
@@ -601,17 +601,26 @@ bool llvm::stripNonLineTableDebugInfo(Mo
     }
     for (auto &BB : F) {
       for (auto &I : BB) {
-        if (I.getDebugLoc() == DebugLoc())
-          continue;
+        auto remapDebugLoc = [&](DebugLoc DL) -> DebugLoc {
+          auto *Scope = DL.getScope();
+          MDNode *InlinedAt = DL.getInlinedAt();
+          Scope = remap(Scope);
+          InlinedAt = remap(InlinedAt);
+          return DebugLoc::get(DL.getLine(), DL.getCol(), Scope, InlinedAt);
+        };
 
-        // Make a replacement.
-        auto &DL = I.getDebugLoc();
-        auto *Scope = DL.getScope();
-        MDNode *InlinedAt = DL.getInlinedAt();
-        Scope = remap(Scope);
-        InlinedAt = remap(InlinedAt);
-        I.setDebugLoc(
-            DebugLoc::get(DL.getLine(), DL.getCol(), Scope, InlinedAt));
+        if (I.getDebugLoc() != DebugLoc())
+          I.setDebugLoc(remapDebugLoc(I.getDebugLoc()));
+
+        // Remap DILocations in untyped MDNodes (e.g., llvm.loop).
+        SmallVector<std::pair<unsigned, MDNode *>, 2> MDs;
+        I.getAllMetadata(MDs);
+        for (auto Attachment : MDs)
+          if (auto *T = dyn_cast_or_null<MDTuple>(Attachment.second))
+            for (unsigned N = 0; N < T->getNumOperands(); ++N)
+              if (auto *Loc = dyn_cast_or_null<DILocation>(T->getOperand(N)))
+                if (Loc != DebugLoc())
+                  T->replaceOperandWith(N, remapDebugLoc(Loc));
       }
     }
   }

Added: llvm/trunk/test/Transforms/Util/strip-nonlinetable-debuginfo-loops.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Util/strip-nonlinetable-debuginfo-loops.ll?rev=299107&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Util/strip-nonlinetable-debuginfo-loops.ll (added)
+++ llvm/trunk/test/Transforms/Util/strip-nonlinetable-debuginfo-loops.ll Thu Mar 30 15:10:56 2017
@@ -0,0 +1,71 @@
+; RUN: opt -S -strip-nonlinetable-debuginfo %s -o %t
+; RUN: cat %t | FileCheck %s
+; RUN: cat %t | FileCheck %s --check-prefix=NEGATIVE
+; void f(volatile int *i) {
+;   while (--*i) {}
+; }
+source_filename = "/tmp/loop.c"
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.12.0"
+
+define void @f(i32* %i) local_unnamed_addr #0 !dbg !7 {
+entry:
+  tail call void @llvm.dbg.value(metadata i32* %i, i64 0, metadata !14, metadata !15), !dbg !16
+  br label %while.cond, !dbg !17
+
+while.cond:                                       ; preds = %while.cond, %entry
+  %0 = load volatile i32, i32* %i, align 4, !dbg !18, !tbaa !19
+  %dec = add nsw i32 %0, -1, !dbg !18
+  store volatile i32 %dec, i32* %i, align 4, !dbg !18, !tbaa !19
+  %tobool = icmp eq i32 %dec, 0, !dbg !17
+  ; CHECK: !llvm.loop ![[LOOP:[0-9]+]]
+  br i1 %tobool, label %while.end, label %while.cond, !dbg !17, !llvm.loop !23
+
+while.end:                                        ; preds = %while.cond
+  ret void, !dbg !25
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
+
+attributes #0 = { nounwind ssp uwtable }
+attributes #1 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+; CHECK: ![[CU:.*]] = distinct !DICompileUnit(language: DW_LANG_C99,
+; CHECK-SAME:                                 emissionKind: LineTablesOnly
+; NEGATIVE-NOT: !DICompileUnit({{.*}} emissionKind: FullDebug
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 5.0.0 (trunk 298880) (llvm/trunk 298875)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "/tmp/loop.c", directory: "/")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"PIC Level", i32 2}
+!6 = !{!"clang version 5.0.0 (trunk 298880) (llvm/trunk 298875)"}
+; CHECK: ![[F:[0-9]]] = distinct !DISubprogram(name: "f", scope: !1
+!7 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !13)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null, !10}
+!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 64)
+!11 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !12)
+; NEGATIVE-NOT: !DIBasicType(name: "int",
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !{!14}
+!14 = !DILocalVariable(name: "i", arg: 1, scope: !7, file: !1, line: 1, type: !10)
+!15 = !DIExpression()
+!16 = !DILocation(line: 1, column: 22, scope: !7)
+; CHECK: ![[BEGIN:[0-9]+]] = !DILocation(line: 2, column: 3, scope: ![[F]])
+!17 = !DILocation(line: 2, column: 3, scope: !7)
+!18 = !DILocation(line: 2, column: 10, scope: !7)
+!19 = !{!20, !20, i64 0}
+!20 = !{!"int", !21, i64 0}
+!21 = !{!"omnipotent char", !22, i64 0}
+!22 = !{!"Simple C/C++ TBAA"}
+; CHECK: ![[LOOP]] = distinct !{![[LOOP]], ![[BEGIN]], ![[END:[0-9]+]]}
+!23 = distinct !{!23, !17, !24}
+; CHECK: ![[END]] = !DILocation(line: 3, column: 3, scope: ![[F]])
+!24 = !DILocation(line: 3, column: 3, scope: !7)
+!25 = !DILocation(line: 4, column: 1, scope: !7)