From: Dan Gohman Date: Mon, 25 Oct 2010 21:48:30 +0000 (+0000) Subject: Factor out the code for creating the Root and Char nodes, so that X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=224d75972a836b06e2ca708d1eafdac6f762c487;p=clang Factor out the code for creating the Root and Char nodes, so that they can be used outside of the main getTBAAInfo function. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@117320 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/CodeGen/CodeGenTBAA.cpp b/lib/CodeGen/CodeGenTBAA.cpp index 5df10589e2..d8618f0d3a 100644 --- a/lib/CodeGen/CodeGenTBAA.cpp +++ b/lib/CodeGen/CodeGenTBAA.cpp @@ -32,6 +32,28 @@ CodeGenTBAA::CodeGenTBAA(ASTContext &Ctx, llvm::LLVMContext& VMContext, CodeGenTBAA::~CodeGenTBAA() { } +llvm::MDNode *CodeGenTBAA::getRoot() { + // Define the root of the tree. This identifies the tree, so that + // if our LLVM IR is linked with LLVM IR from a different front-end + // (or a different version of this front-end), their TBAA trees will + // remain distinct, and the optimizer will treat them conservatively. + if (!Root) + Root = getTBAAInfoForNamedType("Simple C/C++ TBAA", 0); + + return Root; +} + +llvm::MDNode *CodeGenTBAA::getChar() { + // Define the root of the tree for user-accessible memory. C and C++ + // give special powers to char and certain similar types. However, + // these special powers only cover user-accessible memory, and doesn't + // include things like vtables. + if (!Char) + Char = getTBAAInfoForNamedType("omnipotent char", getRoot()); + + return Char; +} + /// getTBAAInfoForNamedType - Create a TBAA tree node with the given string /// as its identifier, and the given Parent node as its tree parent. llvm::MDNode *CodeGenTBAA::getTBAAInfoForNamedType(llvm::StringRef NameStr, @@ -51,21 +73,6 @@ CodeGenTBAA::getTBAAInfo(QualType QTy) { if (llvm::MDNode *N = MetadataCache[Ty]) return N; - // If this is our first node, create the initial tree. - if (!Root) { - // Define the root of the tree. This identifies the tree, so that - // if our LLVM IR is linked with LLVM IR from a different front-end - // (or a different version of this front-end), their TBAA trees will - // remain distinct, and the optimizer will treat them conservatively. - Root = getTBAAInfoForNamedType("Simple C/C++ TBAA", 0); - - // Define the root of the tree for user-accessible memory. C and C++ - // give special powers to char and certain similar types. However, - // these special powers only cover user-accessible memory, and doesn't - // include things like vtables. - Char = getTBAAInfoForNamedType("omnipotent char", Root); - } - // Handle builtin types. if (const BuiltinType *BTy = dyn_cast(Ty)) { switch (BTy->getKind()) { @@ -78,7 +85,7 @@ CodeGenTBAA::getTBAAInfo(QualType QTy) { case BuiltinType::Char_S: case BuiltinType::UChar: case BuiltinType::SChar: - return Char; + return getChar(); // Unsigned types can alias their corresponding signed types. case BuiltinType::UShort: @@ -97,7 +104,7 @@ CodeGenTBAA::getTBAAInfo(QualType QTy) { // "underlying types". default: return MetadataCache[Ty] = - getTBAAInfoForNamedType(BTy->getName(Features), Char); + getTBAAInfoForNamedType(BTy->getName(Features), getChar()); } } @@ -105,7 +112,8 @@ CodeGenTBAA::getTBAAInfo(QualType QTy) { // TODO: Implement C++'s type "similarity" and consider dis-"similar" // pointers distinct. if (Ty->isPointerType()) - return MetadataCache[Ty] = getTBAAInfoForNamedType("any pointer", Char); + return MetadataCache[Ty] = getTBAAInfoForNamedType("any pointer", + getChar()); // Enum types are distinct types. In C++ they have "underlying types", // however they aren't related for TBAA. @@ -116,7 +124,7 @@ CodeGenTBAA::getTBAAInfo(QualType QTy) { // members into a single identifying MDNode. if (!Features.CPlusPlus && ETy->getDecl()->getTypedefForAnonDecl()) - return MetadataCache[Ty] = Char; + return MetadataCache[Ty] = getChar(); // In C++ mode, types have linkage, so we can rely on the ODR and // on their mangled names, if they're external. @@ -124,15 +132,15 @@ CodeGenTBAA::getTBAAInfo(QualType QTy) { // decl with local linkage or no linkage? if (Features.CPlusPlus && ETy->getDecl()->getLinkage() != ExternalLinkage) - return MetadataCache[Ty] = Char; + return MetadataCache[Ty] = getChar(); // TODO: This is using the RTTI name. Is there a better way to get // a unique string for a type? llvm::SmallString<256> OutName; MContext.mangleCXXRTTIName(QualType(ETy, 0), OutName); - return MetadataCache[Ty] = getTBAAInfoForNamedType(OutName, Char); + return MetadataCache[Ty] = getTBAAInfoForNamedType(OutName, getChar()); } // For now, handle any other kind of type conservatively. - return MetadataCache[Ty] = Char; + return MetadataCache[Ty] = getChar(); } diff --git a/lib/CodeGen/CodeGenTBAA.h b/lib/CodeGen/CodeGenTBAA.h index e49d336d38..5a56079fc9 100644 --- a/lib/CodeGen/CodeGenTBAA.h +++ b/lib/CodeGen/CodeGenTBAA.h @@ -44,13 +44,16 @@ class CodeGenTBAA { /// MetadataCache - This maps clang::Types to llvm::MDNodes describing them. llvm::DenseMap MetadataCache; - /// Root - This is the mdnode for the root of the metadata type graph - /// for this translation unit. llvm::MDNode *Root; + llvm::MDNode *Char; - /// Char - This is the mdnode for "char", which is special, and any types + /// getRoot - This is the mdnode for the root of the metadata type graph + /// for this translation unit. + llvm::MDNode *getRoot(); + + /// getChar - This is the mdnode for "char", which is special, and any types /// considered to be equivalent to it. - llvm::MDNode *Char; + llvm::MDNode *getChar(); llvm::MDNode *getTBAAInfoForNamedType(llvm::StringRef NameStr, llvm::MDNode *Parent);