Commit 5c83bede authored by Adrian Prantl's avatar Adrian Prantl
Browse files

More principled implementation of DISubprogram::describes() 

Previously we would also accept DISubprograms that matched in name
only, but this doesn't appear to be necessary any more.

I did a Full and Thin LTO build of Clang and it completed without a warning.

Differential Revision: https://reviews.llvm.org/D75213
parent e691b301

llvm/lib/IR/DebugInfoMetadata.cpp

+1 −6
Original line number Diff line number Diff line
@@ -660,12 +660,7 @@ DISubprogram *DISubprogram::getImpl( 


bool DISubprogram::describes(const Function *F) const {

  assert(F && "Invalid function");

  if (F->getSubprogram() == this)

    return true;

  StringRef Name = getLinkageName();

  if (Name.empty())

    Name = getName();

  return F->getName() == Name;

  return F->getSubprogram() == this;

}



DILexicalBlock *DILexicalBlock::getImpl(LLVMContext &Context, Metadata *Scope,

llvm/lib/IR/Verifier.cpp

+1 −4
Original line number Diff line number Diff line
@@ -2364,8 +2364,7 @@ void Verifier::visitFunction(const Function &F) { 
  if (!HasDebugInfo)

    return;



  // Check that all !dbg attachments lead to back to N (or, at least, another

  // subprogram that describes the same function).

  // Check that all !dbg attachments lead to back to N.

  //

  // FIXME: Check this incrementally while visiting !dbg attachments.

  // FIXME: Only check when N is the canonical subprogram for F.
@@ -2394,11 +2393,9 @@ void Verifier::visitFunction(const Function &F) { 
    if (SP && ((Scope != SP) && !Seen.insert(SP).second))

      return;



    // FIXME: Once N is canonical, check "SP == &N".

    AssertDI(SP->describes(&F),

             "!dbg attachment points at wrong subprogram for function", N, &F,

             &I, DL, Scope, SP);

    visitMDNode(*SP);

  };

  for (auto &BB : F)

    for (auto &I : BB) {

llvm/test/Verifier/disubprogram-name-match-only.ll

0 → 100644
+26 −0
Original line number Diff line number Diff line 
; RUN: llvm-as -disable-output <%s 2>&1| FileCheck %s



define void @f() !dbg !14 {

  ret void, !dbg !5

}



!llvm.module.flags = !{!15}

!llvm.dbg.cu = !{!4}



!0 = !{null}

!1 = distinct !DICompositeType(tag: DW_TAG_structure_type)

!2 = !DIFile(filename: "f.c", directory: "/")

!3 = !DISubroutineType(types: !0)

!4 = distinct !DICompileUnit(language: DW_LANG_C, file: !2)

; CHECK: !dbg attachment points at wrong subprogram for function

; CHECK: warning: ignoring invalid debug info

!5 = !DILocation(line: 1, scope: !9)

!9 = distinct !DISubprogram(name: "f", scope: !1,

                            file: !2, line: 1, type: !3, isLocal: true,

                            isDefinition: true, scopeLine: 2,

                            unit: !4)

!14 = distinct !DISubprogram(name: "f", scope: !1,

                            file: !2, line: 1, type: !3, isLocal: true,

                            isDefinition: true, scopeLine: 2,

                            unit: !4)

!15 = !{i32 1, !"Debug Info Version", i32 3}