From: David Blaikie Date: Tue, 6 May 2014 03:41:57 +0000 (+0000) Subject: PR19598: Provide the ability to RAUW a declaration with itself, creating a non-tempor... X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=40a1b74db686fc3f153dcc01713d1bb51d3c24da;p=oota-llvm.git PR19598: Provide the ability to RAUW a declaration with itself, creating a non-temporary copy and using that to RAUW. Also, provide the ability to create temporary and non-temporary declarations, as not all declarations may be replaced by definitions later on. This provides the necessary infrastructure for Clang to fix PR19598, leaking temporary MDNodes in Clang's debug info generation. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208054 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/llvm/IR/DIBuilder.h b/include/llvm/IR/DIBuilder.h index df8cd75de12..8b05bbb4fdb 100644 --- a/include/llvm/IR/DIBuilder.h +++ b/include/llvm/IR/DIBuilder.h @@ -434,7 +434,7 @@ namespace llvm { /// flag set. DIType createObjectPointerType(DIType Ty); - /// createForwardDecl - Create a temporary forward-declared type. + /// \brief Create a permanent forward-declared type. DICompositeType createForwardDecl(unsigned Tag, StringRef Name, DIDescriptor Scope, DIFile F, unsigned Line, unsigned RuntimeLang = 0, @@ -442,6 +442,12 @@ namespace llvm { uint64_t AlignInBits = 0, StringRef UniqueIdentifier = StringRef()); + /// \brief Create a temporary forward-declared type. + DICompositeType createReplaceableForwardDecl( + unsigned Tag, StringRef Name, DIDescriptor Scope, DIFile F, + unsigned Line, unsigned RuntimeLang = 0, uint64_t SizeInBits = 0, + uint64_t AlignInBits = 0, StringRef UniqueIdentifier = StringRef()); + /// retainType - Retain DIType in a module even if it is not referenced /// through debug info anchors. void retainType(DIType T); diff --git a/include/llvm/IR/DebugInfo.h b/include/llvm/IR/DebugInfo.h index 82b25ace449..1b97f625421 100644 --- a/include/llvm/IR/DebugInfo.h +++ b/include/llvm/IR/DebugInfo.h @@ -339,7 +339,7 @@ public: /// replaceAllUsesWith - Replace all uses of debug info referenced by /// this descriptor. - void replaceAllUsesWith(DIDescriptor &D); + void replaceAllUsesWith(LLVMContext &VMContext, DIDescriptor D); void replaceAllUsesWith(MDNode *D); }; diff --git a/lib/IR/DIBuilder.cpp b/lib/IR/DIBuilder.cpp index 8d7d21eb168..528b43cdc88 100644 --- a/lib/IR/DIBuilder.cpp +++ b/lib/IR/DIBuilder.cpp @@ -901,6 +901,40 @@ DIBuilder::createForwardDecl(unsigned Tag, StringRef Name, DIDescriptor Scope, UniqueIdentifier.empty() ? nullptr : MDString::get(VMContext, UniqueIdentifier) }; + MDNode *Node = MDNode::get(VMContext, Elts); + DICompositeType RetTy(Node); + assert(RetTy.isCompositeType() && + "createForwardDecl result should be a DIType"); + if (!UniqueIdentifier.empty()) + retainType(RetTy); + return RetTy; +} + +/// createForwardDecl - Create a temporary forward-declared type that +/// can be RAUW'd if the full type is seen. +DICompositeType DIBuilder::createReplaceableForwardDecl( + unsigned Tag, StringRef Name, DIDescriptor Scope, DIFile F, unsigned Line, + unsigned RuntimeLang, uint64_t SizeInBits, uint64_t AlignInBits, + StringRef UniqueIdentifier) { + // Create a temporary MDNode. + Value *Elts[] = { + GetTagConstant(VMContext, Tag), + F.getFileNode(), + DIScope(getNonCompileUnitScope(Scope)).getRef(), + MDString::get(VMContext, Name), + ConstantInt::get(Type::getInt32Ty(VMContext), Line), + ConstantInt::get(Type::getInt64Ty(VMContext), SizeInBits), + ConstantInt::get(Type::getInt64Ty(VMContext), AlignInBits), + ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Offset + ConstantInt::get(Type::getInt32Ty(VMContext), DIDescriptor::FlagFwdDecl), + nullptr, + DIArray(), + ConstantInt::get(Type::getInt32Ty(VMContext), RuntimeLang), + nullptr, + nullptr, //TemplateParams + UniqueIdentifier.empty() ? nullptr + : MDString::get(VMContext, UniqueIdentifier) + }; MDNode *Node = MDNode::getTemporary(VMContext, Elts); DICompositeType RetTy(Node); assert(RetTy.isCompositeType() && diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp index cf8afe251ad..db9e56defa1 100644 --- a/lib/IR/DebugInfo.cpp +++ b/lib/IR/DebugInfo.cpp @@ -335,7 +335,7 @@ unsigned DIArray::getNumElements() const { /// replaceAllUsesWith - Replace all uses of the MDNode used by this /// type with the one in the passed descriptor. -void DIType::replaceAllUsesWith(DIDescriptor &D) { +void DIType::replaceAllUsesWith(LLVMContext &VMContext, DIDescriptor D) { assert(DbgNode && "Trying to replace an unverified type!"); @@ -344,13 +344,19 @@ void DIType::replaceAllUsesWith(DIDescriptor &D) { // which, due to uniquing, has merged with the source. We shield clients from // this detail by allowing a value to be replaced with replaceAllUsesWith() // itself. - if (DbgNode != D) { - MDNode *Node = const_cast(DbgNode); - const MDNode *DN = D; - const Value *V = cast_or_null(DN); - Node->replaceAllUsesWith(const_cast(V)); - MDNode::deleteTemporary(Node); + const MDNode *DN = D; + if (DbgNode == DN) { + SmallVector Ops(DbgNode->getNumOperands()); + for (size_t i = 0; i != Ops.size(); ++i) + Ops[i] = DbgNode->getOperand(i); + DN = MDNode::get(VMContext, Ops); } + + MDNode *Node = const_cast(DbgNode); + const Value *V = cast_or_null(DN); + Node->replaceAllUsesWith(const_cast(V)); + MDNode::deleteTemporary(Node); + DbgNode = D; } /// replaceAllUsesWith - Replace all uses of the MDNode used by this @@ -358,19 +364,12 @@ void DIType::replaceAllUsesWith(DIDescriptor &D) { void DIType::replaceAllUsesWith(MDNode *D) { assert(DbgNode && "Trying to replace an unverified type!"); - - // Since we use a TrackingVH for the node, its easy for clients to manufacture - // legitimate situations where they want to replaceAllUsesWith() on something - // which, due to uniquing, has merged with the source. We shield clients from - // this detail by allowing a value to be replaced with replaceAllUsesWith() - // itself. - if (DbgNode != D) { - MDNode *Node = const_cast(DbgNode); - const MDNode *DN = D; - const Value *V = cast_or_null(DN); - Node->replaceAllUsesWith(const_cast(V)); - MDNode::deleteTemporary(Node); - } + assert(DbgNode != D && "This replacement should always happen"); + MDNode *Node = const_cast(DbgNode); + const MDNode *DN = D; + const Value *V = cast_or_null(DN); + Node->replaceAllUsesWith(const_cast(V)); + MDNode::deleteTemporary(Node); } /// Verify - Verify that a compile unit is well formed.