Standardize the parsing of function type attributes in a way that

follows (as conservatively as possible) gcc's current behavior:  attributes
written on return types that don't apply there are applied to the function
instead, etc.  Only parse CC attributes as type attributes, not as decl attributes;
don't accepet noreturn as a decl attribute on ValueDecls, either (it still
needs to apply to other decls, like blocks).  Consistently consume CC/noreturn
information throughout codegen;  enforce this by removing their default values
in CodeGenTypes::getFunctionInfo().



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95436 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 29 deletions

diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index ce361f08fe..7a47d5bcc0 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -33,12 +33,19 @@ using namespace CodeGen;
 
 // FIXME: Use iterator and sidestep silly type array creation.
 
+static unsigned ClangCallConvToLLVMCallConv(CallingConv CC) {
+  switch (CC) {
+  default: return llvm::CallingConv::C;
+  case CC_X86StdCall: return llvm::CallingConv::X86_StdCall;
+  case CC_X86FastCall: return llvm::CallingConv::X86_FastCall;
+  }
+}
+
 const
 CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionNoProtoType *FTNP) {
-  // FIXME: Set calling convention correctly, it needs to be associated with the
-  // type somehow.
   return getFunctionInfo(FTNP->getResultType(),
-                         llvm::SmallVector<QualType, 16>(), 0);
+                         llvm::SmallVector<QualType, 16>(),
+                         FTNP->getCallConv(), FTNP->getNoReturnAttr());
 }
 
 const
@@ -47,20 +54,19 @@ CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionProtoType *FTP) {
   // FIXME: Kill copy.
   for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i)
     ArgTys.push_back(FTP->getArgType(i));
-  // FIXME: Set calling convention correctly, it needs to be associated with the
-  // type somehow.
-  return getFunctionInfo(FTP->getResultType(), ArgTys, 0);
+  return getFunctionInfo(FTP->getResultType(), ArgTys,
+                         FTP->getCallConv(), FTP->getNoReturnAttr());
 }
 
-static unsigned getCallingConventionForDecl(const Decl *D) {
+static CallingConv getCallingConventionForDecl(const Decl *D) {
   // Set the appropriate calling convention for the Function.
   if (D->hasAttr<StdCallAttr>())
-    return llvm::CallingConv::X86_StdCall;
+    return CC_X86StdCall;
 
   if (D->hasAttr<FastCallAttr>())
-    return llvm::CallingConv::X86_FastCall;
+    return CC_X86FastCall;
 
-  return llvm::CallingConv::C;
+  return CC_C;
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXRecordDecl *RD,
@@ -75,7 +81,8 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXRecordDecl *RD,
   
   // FIXME: Set calling convention correctly, it needs to be associated with the
   // type somehow.
-  return getFunctionInfo(FTP->getResultType(), ArgTys, 0);
+  return getFunctionInfo(FTP->getResultType(), ArgTys,
+                         FTP->getCallConv(), FTP->getNoReturnAttr());
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXMethodDecl *MD) {
@@ -87,8 +94,8 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXMethodDecl *MD) {
   const FunctionProtoType *FTP = MD->getType()->getAs<FunctionProtoType>();
   for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i)
     ArgTys.push_back(FTP->getArgType(i));
-  return getFunctionInfo(FTP->getResultType(), ArgTys,
-                         getCallingConventionForDecl(MD));
+  return getFunctionInfo(FTP->getResultType(), ArgTys, FTP->getCallConv(),
+                         FTP->getNoReturnAttr());
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXConstructorDecl *D, 
@@ -105,8 +112,8 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXConstructorDecl *D,
   const FunctionProtoType *FTP = D->getType()->getAs<FunctionProtoType>();
   for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i)
     ArgTys.push_back(FTP->getArgType(i));
-  return getFunctionInfo(FTP->getResultType(), ArgTys,
-                         getCallingConventionForDecl(D));
+  return getFunctionInfo(FTP->getResultType(), ArgTys, FTP->getCallConv(),
+                         FTP->getNoReturnAttr());
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXDestructorDecl *D,
@@ -123,8 +130,8 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXDestructorDecl *D,
   const FunctionProtoType *FTP = D->getType()->getAs<FunctionProtoType>();
   for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i)
     ArgTys.push_back(FTP->getArgType(i));
-  return getFunctionInfo(FTP->getResultType(), ArgTys,
-                         getCallingConventionForDecl(D));
+  return getFunctionInfo(FTP->getResultType(), ArgTys, FTP->getCallConv(),
+                         FTP->getNoReturnAttr());
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionDecl *FD) {
@@ -132,19 +139,19 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionDecl *FD) {
     if (MD->isInstance())
       return getFunctionInfo(MD);
 
-  unsigned CallingConvention = getCallingConventionForDecl(FD);
   const FunctionType *FTy = FD->getType()->getAs<FunctionType>();
   if (const FunctionNoProtoType *FNTP = dyn_cast<FunctionNoProtoType>(FTy))
     return getFunctionInfo(FNTP->getResultType(), 
                            llvm::SmallVector<QualType, 16>(),
-                           CallingConvention);
+                           FNTP->getCallConv(), FNTP->getNoReturnAttr());
   
   const FunctionProtoType *FPT = cast<FunctionProtoType>(FTy);
   llvm::SmallVector<QualType, 16> ArgTys;
   // FIXME: Kill copy.
   for (unsigned i = 0, e = FPT->getNumArgs(); i != e; ++i)
     ArgTys.push_back(FPT->getArgType(i));
-  return getFunctionInfo(FPT->getResultType(), ArgTys, CallingConvention);
+  return getFunctionInfo(FPT->getResultType(), ArgTys,
+                         FPT->getCallConv(), FPT->getNoReturnAttr());
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const ObjCMethodDecl *MD) {
@@ -156,37 +163,43 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const ObjCMethodDecl *MD) {
          e = MD->param_end(); i != e; ++i)
     ArgTys.push_back((*i)->getType());
   return getFunctionInfo(MD->getResultType(), ArgTys,
-                         getCallingConventionForDecl(MD));
+                         getCallingConventionForDecl(MD),
+                         /*NoReturn*/ false);
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy,
                                                     const CallArgList &Args,
-                                                    unsigned CallingConvention){
+                                                    CallingConv CC,
+                                                    bool NoReturn) {
   // FIXME: Kill copy.
   llvm::SmallVector<QualType, 16> ArgTys;
   for (CallArgList::const_iterator i = Args.begin(), e = Args.end();
        i != e; ++i)
     ArgTys.push_back(i->second);
-  return getFunctionInfo(ResTy, ArgTys, CallingConvention);
+  return getFunctionInfo(ResTy, ArgTys, CC, NoReturn);
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy,
                                                     const FunctionArgList &Args,
-                                                    unsigned CallingConvention){
+                                                    CallingConv CC,
+                                                    bool NoReturn) {
   // FIXME: Kill copy.
   llvm::SmallVector<QualType, 16> ArgTys;
   for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
        i != e; ++i)
     ArgTys.push_back(i->second);
-  return getFunctionInfo(ResTy, ArgTys, CallingConvention);
+  return getFunctionInfo(ResTy, ArgTys, CC, NoReturn);
 }
 
 const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy,
                                   const llvm::SmallVector<QualType, 16> &ArgTys,
-                                                    unsigned CallingConvention){
+                                                    CallingConv CallConv,
+                                                    bool NoReturn) {
+  unsigned CC = ClangCallConvToLLVMCallConv(CallConv);
+
   // Lookup or create unique function info.
   llvm::FoldingSetNodeID ID;
-  CGFunctionInfo::Profile(ID, CallingConvention, ResTy,
+  CGFunctionInfo::Profile(ID, CC, NoReturn, ResTy,
                           ArgTys.begin(), ArgTys.end());
 
   void *InsertPos = 0;
@@ -195,7 +208,7 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy,
     return *FI;
 
   // Construct the function info.
-  FI = new CGFunctionInfo(CallingConvention, ResTy, ArgTys);
+  FI = new CGFunctionInfo(CC, NoReturn, ResTy, ArgTys);
   FunctionInfos.InsertNode(FI, InsertPos);
 
   // Compute ABI information.
@@ -205,10 +218,12 @@ const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy,
 }
 
 CGFunctionInfo::CGFunctionInfo(unsigned _CallingConvention,
+                               bool _NoReturn,
                                QualType ResTy,
                                const llvm::SmallVector<QualType, 16> &ArgTys) 
   : CallingConvention(_CallingConvention),
-    EffectiveCallingConvention(_CallingConvention)
+    EffectiveCallingConvention(_CallingConvention),
+    NoReturn(_NoReturn)
 {
   NumArgs = ArgTys.size();
   Args = new ArgInfo[1 + NumArgs];
@@ -490,6 +505,9 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
 
   CallingConv = FI.getEffectiveCallingConvention();
 
+  if (FI.isNoReturn())
+    FuncAttrs |= llvm::Attribute::NoReturn;
+
   // FIXME: handle sseregparm someday...
   if (TargetDecl) {
     if (TargetDecl->hasAttr<NoThrowAttr>())