[DebugInfo] Refactoring DIType::setFlags to DIType::cloneWithFlags, NFC

and using the latter in DIBuilder::createArtificialType and
DIBuilder::createObjectPointerType methods as well as introducing
mirroring DISubprogram::cloneWithFlags and
DIBuilder::createArtificialSubprogram methods.

The primary goal here is to add createArtificialSubprogram to support
a pass downstream while keeping the method consistent with the
existing ones and making sure we don't encourage changing already
created DI-nodes.

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D47615

llvm-svn: 333806

llvm/include/llvm-c/DebugInfo.h

@@ -678,8 +678,7 @@ LLVMDIBuilderCreateObjCProperty(LLVMDIBuilderRef Builder,
                                 LLVMMetadataRef Ty);
 
 /**
- * Create a new DIType* with the "object pointer"
- * flag set.
+ * Create a uniqued DIType* clone with FlagObjectPointer and FlagArtificial set.
  * \param Builder   The DIBuilder.
  * \param Type      The underlying type to which this pointer points.
  */
@@ -851,7 +850,7 @@ LLVMMetadataRef LLVMDIBuilderCreateClassType(LLVMDIBuilderRef Builder,
     const char *UniqueIdentifier, size_t UniqueIdentifierLen);
 
 /**
- * Create a new DIType* with "artificial" flag set.
+ * Create a uniqued DIType* clone with FlagArtificial set.
  * \param Builder     The DIBuilder.
  * \param Type        The underlying type.
  */

llvm/include/llvm/IR/DIBuilder.h

@@ -515,12 +515,15 @@ namespace llvm {
                          DINode::DIFlags Flags = DINode::FlagZero,
                          unsigned CC = 0);
 
-    /// Create a new DIType* with "artificial" flag set.
-    DIType *createArtificialType(DIType *Ty);
+    /// Create a distinct clone of \p SP with FlagArtificial set.
+    static DISubprogram *createArtificialSubprogram(DISubprogram *SP);
 
-    /// Create a new DIType* with the "object pointer"
-    /// flag set.
-    DIType *createObjectPointerType(DIType *Ty);
+    /// Create a uniqued clone of \p Ty with FlagArtificial set.
+    static DIType *createArtificialType(DIType *Ty);
+
+    /// Create a uniqued clone of \p Ty with FlagObjectPointer and
+    /// FlagArtificial set.
+    static DIType *createObjectPointerType(DIType *Ty);
 
     /// Create a permanent forward-declared type.
     DICompositeType *createForwardDecl(unsigned Tag, StringRef Name,

llvm/include/llvm/IR/DebugInfoMetadata.h

@@ -679,9 +679,11 @@ public:
   Metadata *getRawScope() const { return getOperand(1); }
   MDString *getRawName() const { return getOperandAs<MDString>(2); }
 
-  void setFlags(DIFlags NewFlags) {
-    assert(!isUniqued() && "Cannot set flags on uniqued nodes");
-    Flags = NewFlags;
+  /// Returns a new temporary DIType with updated Flags
+  TempDIType cloneWithFlags(DIFlags NewFlags) const {
+    auto NewTy = clone();
+    NewTy->Flags = NewFlags;
+    return NewTy;
   }
 
   bool isPrivate() const {
@@ -1679,6 +1681,13 @@ public:
 
   TempDISubprogram clone() const { return cloneImpl(); }
 
+  /// Returns a new temporary DISubprogram with updated Flags
+  TempDISubprogram cloneWithFlags(DIFlags NewFlags) const {
+    auto NewSP = clone();
+    NewSP->Flags = NewFlags;
+    return NewSP;
+  }
+
 public:
   unsigned getLine() const { return Line; }
   unsigned getVirtuality() const { return Virtuality; }

llvm/lib/IR/DIBuilder.cpp

@@ -535,10 +535,14 @@ DICompositeType *DIBuilder::createVectorType(uint64_t Size,
   return R;
 }
 
-static DIType *createTypeWithFlags(LLVMContext &Context, DIType *Ty,
+DISubprogram *DIBuilder::createArtificialSubprogram(DISubprogram *SP) {
+  auto NewSP = SP->cloneWithFlags(SP->getFlags() | DINode::FlagArtificial);
+  return MDNode::replaceWithDistinct(std::move(NewSP));
+}
+
+static DIType *createTypeWithFlags(const DIType *Ty,
                                    DINode::DIFlags FlagsToSet) {
-  auto NewTy = Ty->clone();
-  NewTy->setFlags(NewTy->getFlags() | FlagsToSet);
+  auto NewTy = Ty->cloneWithFlags(Ty->getFlags() | FlagsToSet);
   return MDNode::replaceWithUniqued(std::move(NewTy));
 }
 
@@ -546,7 +550,7 @@ DIType *DIBuilder::createArtificialType(DIType *Ty) {
   // FIXME: Restrict this to the nodes where it's valid.
   if (Ty->isArtificial())
     return Ty;
-  return createTypeWithFlags(VMContext, Ty, DINode::FlagArtificial);
+  return createTypeWithFlags(Ty, DINode::FlagArtificial);
 }
 
 DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
@@ -554,7 +558,7 @@ DIType *DIBuilder::createObjectPointerType(DIType *Ty) {
   if (Ty->isObjectPointer())
     return Ty;
   DINode::DIFlags Flags = DINode::FlagObjectPointer | DINode::FlagArtificial;
-  return createTypeWithFlags(VMContext, Ty, Flags);
+  return createTypeWithFlags(Ty, Flags);
 }
 
 void DIBuilder::retainType(DIScope *T) {

llvm/unittests/IR/IRBuilderTest.cpp

@@ -459,6 +459,62 @@ TEST_F(IRBuilderTest, DIBuilder) {
   EXPECT_TRUE(verifyModule(*M));
 }
 
+TEST_F(IRBuilderTest, createArtificialSubprogram) {
+  IRBuilder<> Builder(BB);
+  DIBuilder DIB(*M);
+  auto File = DIB.createFile("main.c", "/");
+  auto CU = DIB.createCompileUnit(dwarf::DW_LANG_C, File, "clang",
+                                  /*isOptimized=*/true, /*Flags=*/"",
+                                  /*Runtime Version=*/0);
+  auto Type = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
+  auto SP = DIB.createFunction(CU, "foo", /*LinkageName=*/"", File,
+                               /*LineNo=*/1, Type, /*isLocalToUnit=*/false,
+                               /*isDefinition=*/true, /*ScopeLine=*/2,
+                               DINode::FlagZero, /*isOptimized=*/true);
+  EXPECT_TRUE(SP->isDistinct());
+
+  F->setSubprogram(SP);
+  AllocaInst *I = Builder.CreateAlloca(Builder.getInt8Ty());
+  ReturnInst *R = Builder.CreateRetVoid();
+  I->setDebugLoc(DebugLoc::get(3, 2, SP));
+  R->setDebugLoc(DebugLoc::get(4, 2, SP));
+  DIB.finalize();
+  EXPECT_FALSE(verifyModule(*M));
+
+  Function *G = Function::Create(F->getFunctionType(),
+                                 Function::ExternalLinkage, "", M.get());
+  BasicBlock *GBB = BasicBlock::Create(Ctx, "", G);
+  Builder.SetInsertPoint(GBB);
+  I->removeFromParent();
+  Builder.Insert(I);
+  Builder.CreateRetVoid();
+  EXPECT_FALSE(verifyModule(*M));
+
+  DISubprogram *GSP = DIBuilder::createArtificialSubprogram(F->getSubprogram());
+  EXPECT_EQ(SP->getFile(), GSP->getFile());
+  EXPECT_EQ(SP->getType(), GSP->getType());
+  EXPECT_EQ(SP->getLine(), GSP->getLine());
+  EXPECT_EQ(SP->getScopeLine(), GSP->getScopeLine());
+  EXPECT_TRUE(GSP->isDistinct());
+
+  G->setSubprogram(GSP);
+  EXPECT_TRUE(verifyModule(*M));
+
+  auto *InlinedAtNode =
+      DILocation::getDistinct(Ctx, GSP->getScopeLine(), 0, GSP);
+  DebugLoc DL = I->getDebugLoc();
+  DenseMap<const MDNode *, MDNode *> IANodes;
+  auto IA = DebugLoc::appendInlinedAt(DL, InlinedAtNode, Ctx, IANodes);
+  auto NewDL = DebugLoc::get(DL.getLine(), DL.getCol(), DL.getScope(), IA);
+  I->setDebugLoc(NewDL);
+  EXPECT_FALSE(verifyModule(*M));
+
+  EXPECT_EQ("foo", SP->getName());
+  EXPECT_EQ("foo", GSP->getName());
+  EXPECT_FALSE(SP->isArtificial());
+  EXPECT_TRUE(GSP->isArtificial());
+}
+
 TEST_F(IRBuilderTest, InsertExtractElement) {
   IRBuilder<> Builder(BB);
 

llvm/unittests/IR/MetadataTest.cpp

@@ -1051,7 +1051,7 @@ TEST_F(DITypeTest, clone) {
   EXPECT_EQ(N, MDNode::replaceWithUniqued(std::move(Temp)));
 }
 
-TEST_F(DITypeTest, setFlags) {
+TEST_F(DITypeTest, cloneWithFlags) {
   // void (void)
   Metadata *TypesOps[] = {nullptr};
   Metadata *Types = MDTuple::get(Context, TypesOps);
@@ -1059,17 +1059,15 @@ TEST_F(DITypeTest, setFlags) {
   DIType *D =
       DISubroutineType::getDistinct(Context, DINode::FlagZero, 0, Types);
   EXPECT_EQ(DINode::FlagZero, D->getFlags());
-  D->setFlags(DINode::FlagRValueReference);
-  EXPECT_EQ(DINode::FlagRValueReference, D->getFlags());
-  D->setFlags(DINode::FlagZero);
+  TempDIType D2 = D->cloneWithFlags(DINode::FlagRValueReference);
+  EXPECT_EQ(DINode::FlagRValueReference, D2->getFlags());
   EXPECT_EQ(DINode::FlagZero, D->getFlags());
 
   TempDIType T =
       DISubroutineType::getTemporary(Context, DINode::FlagZero, 0, Types);
   EXPECT_EQ(DINode::FlagZero, T->getFlags());
-  T->setFlags(DINode::FlagRValueReference);
-  EXPECT_EQ(DINode::FlagRValueReference, T->getFlags());
-  T->setFlags(DINode::FlagZero);
+  TempDIType T2 = T->cloneWithFlags(DINode::FlagRValueReference);
+  EXPECT_EQ(DINode::FlagRValueReference, T2->getFlags());
   EXPECT_EQ(DINode::FlagZero, T->getFlags());
 }