[llvm] r296005 - Revert "Teach the IR verifier to reject conflicting debug info for function arguments."

[Adrian Prantl via llvm-commits]

Author: adrian
Date: Thu Feb 23 13:13:48 2017
New Revision: 296005

URL: http://llvm.org/viewvc/llvm-project?rev=296005&view=rev
Log:
Revert "Teach the IR verifier to reject conflicting debug info for function arguments."

This reverts commit r295749 while investigating PR32042.

It looks like this check uncovered a problem in the frontend that
needs to be fixed before the check can be enabled again.

Removed:
    llvm/trunk/test/Verifier/fnarg-debuginfo.ll
Modified:
    llvm/trunk/lib/IR/Verifier.cpp

Modified: llvm/trunk/lib/IR/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifier.cpp?rev=296005&r1=296004&r2=296005&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Verifier.cpp (original)
+++ llvm/trunk/lib/IR/Verifier.cpp Thu Feb 23 13:13:48 2017
@@ -297,9 +297,6 @@ class Verifier : public InstVisitor<Veri
   // constant expressions, we can arrive at a particular user many times.
   SmallPtrSet<const Value *, 32> GlobalValueVisited;
 
-  // Keeps track of duplicate function argument debug info.
-  SmallVector<const DILocalVariable *, 16> DebugFnArgs;
-
   TBAAVerifier TBAAVerifyHelper;
 
   void checkAtomicMemAccessSize(Type *Ty, const Instruction *I);
@@ -501,7 +498,6 @@ private:
   void verifySiblingFuncletUnwinds();
 
   void verifyFragmentExpression(const DbgInfoIntrinsic &I);
-  void verifyFnArgs(const DbgInfoIntrinsic &I);
 
   /// Module-level debug info verification...
   void verifyCompileUnits();
@@ -1950,8 +1946,6 @@ void Verifier::verifySiblingFuncletUnwin
 // visitFunction - Verify that a function is ok.
 //
 void Verifier::visitFunction(const Function &F) {
-  DebugFnArgs.clear();
-
   visitGlobalValue(F);
 
   // Check function arguments.
@@ -4354,8 +4348,6 @@ void Verifier::visitDbgIntrinsic(StringR
                                " variable and !dbg attachment",
            &DII, BB, F, Var, Var->getScope()->getSubprogram(), Loc,
            Loc->getScope()->getSubprogram());
-
-  verifyFnArgs(DII);
 }
 
 static uint64_t getVariableSize(const DILocalVariable &V) {
@@ -4424,36 +4416,6 @@ void Verifier::verifyFragmentExpression(
   AssertDI(FragSize != VarSize, "fragment covers entire variable", &I, V, E);
 }
 
-void Verifier::verifyFnArgs(const DbgInfoIntrinsic &I) {
-  DILocalVariable *Var;
-  if (auto *DV = dyn_cast<DbgValueInst>(&I)) {
-    // For performance reasons only check non-inlined ones.
-    if (DV->getDebugLoc()->getInlinedAt())
-      return;
-    Var = DV->getVariable();
-  } else {
-    auto *DD = cast<DbgDeclareInst>(&I);
-    if (DD->getDebugLoc()->getInlinedAt())
-      return;
-    Var = DD->getVariable();
-  }
-  AssertDI(Var, "dbg intrinsic without variable");
-
-  unsigned ArgNo = Var->getArg();
-  if (!ArgNo)
-    return;
-
-  // Verify there are no duplicate function argument debug info entries.
-  // These will cause hard-to-debug assertions in the DWARF backend.
-  if (DebugFnArgs.size() < ArgNo)
-    DebugFnArgs.resize(ArgNo, nullptr);
-
-  auto *Prev = DebugFnArgs[ArgNo - 1];
-  DebugFnArgs[ArgNo - 1] = Var;
-  AssertDI(!Prev || (Prev == Var), "conflicting debug info for argument", &I,
-           Prev, Var);
-}
-
 void Verifier::verifyCompileUnits() {
   auto *CUs = M.getNamedMetadata("llvm.dbg.cu");
   SmallPtrSet<const Metadata *, 2> Listed;

Removed: llvm/trunk/test/Verifier/fnarg-debuginfo.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Verifier/fnarg-debuginfo.ll?rev=296004&view=auto
==============================================================================
--- llvm/trunk/test/Verifier/fnarg-debuginfo.ll (original)
+++ llvm/trunk/test/Verifier/fnarg-debuginfo.ll (removed)
@@ -1,26 +0,0 @@
-; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
-
-declare void @llvm.dbg.declare(metadata, metadata, metadata) 
-declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
-
-define void @foo() !dbg !2 {
-entry:
-  %a = alloca i32
-  ; CHECK: conflicting debug info for argument
-  call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !3, metadata !DIExpression()), !dbg !6
-  call void @llvm.dbg.declare(metadata i32* %a, metadata !4, metadata !DIExpression()), !dbg !6
-  ret void, !dbg !6
-}
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!7, !8}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", emissionKind: FullDebug)
-!1 = !DIFile(filename: "x.c", directory: "/")
-!2 = distinct !DISubprogram(name: "foo", scope: !0, isDefinition: true, unit: !0)
-!3 = !DILocalVariable(name: "a", arg: 1, scope: !2, file: !1, line: 1, type: !5)
-!4 = !DILocalVariable(name: "b", arg: 1, scope: !2, file: !1, line: 1, type: !5)
-!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-!6 = !DILocation(line: 1, scope: !2)
-!7 = !{i32 2, !"Dwarf Version", i32 4}
-!8 = !{i32 1, !"Debug Info Version", i32 3}