Pass the function type instead of the return type to FunctionDecl::Create

Fix places where the return type of a FunctionDecl was being used in
place of the function type

FunctionDecl::Create() takes as its T parameter the type of function
that should be created, not the return type. Passing in the return type
looks to have been copypasta'd around a bit, but the number of correct
usages outweighs the incorrect ones so I've opted for keeping what T is
the same and fixing up the call sites instead.

This fixes a crash in Clang when attempting to compile the following
snippet of code with -fblocks -fsanitize=function -x objective-c++ (my
original repro case):

  void g(void(^)());
  void f()
  {
      __block int a = 0;
        g(^(){ a++; });
  }

as well as the following which only requires -fsanitize=function -x c++:

  void f(char * buf)
  {
      __builtin_os_log_format(buf, "");
  }

Patch by: Ben (bobsayshilol)

Differential revision: https://reviews.llvm.org/D53263

llvm-svn: 346601
diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index 73357f7..e7b0b82 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -3249,29 +3249,32 @@
   ASTContext &C = getContext();
   IdentifierInfo *II
     = &CGM.getContext().Idents.get("__assign_helper_atomic_property_");
-  FunctionDecl *FD = FunctionDecl::Create(C,
-                                          C.getTranslationUnitDecl(),
-                                          SourceLocation(),
-                                          SourceLocation(), II, C.VoidTy,
-                                          nullptr, SC_Static,
-                                          false,
-                                          false);
 
+  QualType ReturnTy = C.VoidTy;
   QualType DestTy = C.getPointerType(Ty);
   QualType SrcTy = Ty;
   SrcTy.addConst();
   SrcTy = C.getPointerType(SrcTy);
 
+  SmallVector<QualType, 2> ArgTys;
+  ArgTys.push_back(DestTy);
+  ArgTys.push_back(SrcTy);
+  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
+
+  FunctionDecl *FD = FunctionDecl::Create(
+      C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
+      FunctionTy, nullptr, SC_Static, false, false);
+
   FunctionArgList args;
-  ImplicitParamDecl DstDecl(getContext(), FD, SourceLocation(), /*Id=*/nullptr,
-                            DestTy, ImplicitParamDecl::Other);
+  ImplicitParamDecl DstDecl(C, FD, SourceLocation(), /*Id=*/nullptr, DestTy,
+                            ImplicitParamDecl::Other);
   args.push_back(&DstDecl);
-  ImplicitParamDecl SrcDecl(getContext(), FD, SourceLocation(), /*Id=*/nullptr,
-                            SrcTy, ImplicitParamDecl::Other);
+  ImplicitParamDecl SrcDecl(C, FD, SourceLocation(), /*Id=*/nullptr, SrcTy,
+                            ImplicitParamDecl::Other);
   args.push_back(&SrcDecl);
 
   const CGFunctionInfo &FI =
-    CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args);
+      CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
 
   llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
 
@@ -3282,7 +3285,7 @@
 
   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
 
-  StartFunction(FD, C.VoidTy, Fn, FI, args);
+  StartFunction(FD, ReturnTy, Fn, FI, args);
 
   DeclRefExpr DstExpr(&DstDecl, false, DestTy,
                       VK_RValue, SourceLocation());
@@ -3321,50 +3324,51 @@
   if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic)))
     return nullptr;
   llvm::Constant *HelperFn = nullptr;
-
   if (hasTrivialGetExpr(PID))
     return nullptr;
   assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null");
   if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty)))
     return HelperFn;
 
-
   ASTContext &C = getContext();
-  IdentifierInfo *II
-  = &CGM.getContext().Idents.get("__copy_helper_atomic_property_");
-  FunctionDecl *FD = FunctionDecl::Create(C,
-                                          C.getTranslationUnitDecl(),
-                                          SourceLocation(),
-                                          SourceLocation(), II, C.VoidTy,
-                                          nullptr, SC_Static,
-                                          false,
-                                          false);
+  IdentifierInfo *II =
+      &CGM.getContext().Idents.get("__copy_helper_atomic_property_");
 
+  QualType ReturnTy = C.VoidTy;
   QualType DestTy = C.getPointerType(Ty);
   QualType SrcTy = Ty;
   SrcTy.addConst();
   SrcTy = C.getPointerType(SrcTy);
 
+  SmallVector<QualType, 2> ArgTys;
+  ArgTys.push_back(DestTy);
+  ArgTys.push_back(SrcTy);
+  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
+
+  FunctionDecl *FD = FunctionDecl::Create(
+      C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
+      FunctionTy, nullptr, SC_Static, false, false);
+
   FunctionArgList args;
-  ImplicitParamDecl DstDecl(getContext(), FD, SourceLocation(), /*Id=*/nullptr,
-                            DestTy, ImplicitParamDecl::Other);
+  ImplicitParamDecl DstDecl(C, FD, SourceLocation(), /*Id=*/nullptr, DestTy,
+                            ImplicitParamDecl::Other);
   args.push_back(&DstDecl);
-  ImplicitParamDecl SrcDecl(getContext(), FD, SourceLocation(), /*Id=*/nullptr,
-                            SrcTy, ImplicitParamDecl::Other);
+  ImplicitParamDecl SrcDecl(C, FD, SourceLocation(), /*Id=*/nullptr, SrcTy,
+                            ImplicitParamDecl::Other);
   args.push_back(&SrcDecl);
 
   const CGFunctionInfo &FI =
-    CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args);
+      CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
 
   llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
 
-  llvm::Function *Fn =
-  llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
-                         "__copy_helper_atomic_property_", &CGM.getModule());
+  llvm::Function *Fn = llvm::Function::Create(
+      LTy, llvm::GlobalValue::InternalLinkage, "__copy_helper_atomic_property_",
+      &CGM.getModule());
 
   CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
 
-  StartFunction(FD, C.VoidTy, Fn, FI, args);
+  StartFunction(FD, ReturnTy, Fn, FI, args);
 
   DeclRefExpr SrcExpr(&SrcDecl, false, SrcTy,
                       VK_RValue, SourceLocation());