[CUDA] Create __host__ and device variants of standard allocator declarations.

[tra]

Summary

Implicit functions are treated as if they were host device and clang does not allow overloading
those with host or device variants.

In order for users to provide their own standard allocators, we must create host and device variants of these declarations during CUDA compilation.

[jlebar]

Is it not possible to write a testcase for this?

[jlebar]

lib/Sema/SemaExprCXX.cpp

2596

Nit, no need for empty parens.

2622

I kind of feel like it would be easier to add a boolean parameter to CreateAllocationFunctionDecl, then you don't need to repeat these two lines.

[tra]

Addressed jlebar's comments.

[jlebar]

lib/Sema/SemaExprCXX.cpp

2596–2601

Oh, I like this way better than a bool arg.

[tra]

Landed in r284879.

lib/Sema/SemaExprCXX.cpp

if (!getLangOpts().CPlusPlus11) {
       EPI.ExceptionSpec.Type = EST_Dynamic;
       EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
     }
   } else {
     EPI.ExceptionSpec =
         getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
   }
 
+  auto CreateAllocationFunctionDecl = [&]() {
     QualType FnType = Context.getFunctionType(Return, Params, EPI);
-  FunctionDecl *Alloc =
-    FunctionDecl::Create(Context, GlobalCtx, SourceLocation(),
-                         SourceLocation(), Name,
-                         FnType, /*TInfo=*/nullptr, SC_None, false, true);
+    FunctionDecl *Alloc = FunctionDecl::Create(
+        Context, GlobalCtx, SourceLocation(), SourceLocation(), Name,
     Alloc->setImplicit();
 
     // Implicit sized deallocation functions always have default visibility.
-  Alloc->addAttr(VisibilityAttr::CreateImplicit(Context,
-                                                VisibilityAttr::Default));
+    Alloc->addAttr(
+        VisibilityAttr::CreateImplicit(Context, VisibilityAttr::Default));
 
-  llvm::SmallVector<ParmVarDecl*, 3> ParamDecls;
+    llvm::SmallVector<ParmVarDecl *, 3> ParamDecls;
     for (QualType T : Params) {
-    ParamDecls.push_back(
-        ParmVarDecl::Create(Context, Alloc, SourceLocation(), SourceLocation(),
-                            nullptr, T, /*TInfo=*/nullptr, SC_None, nullptr));
+      ParamDecls.push_back(ParmVarDecl::Create(
+          Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T,
+          /*TInfo=*/nullptr, SC_None, nullptr));
       ParamDecls.back()->setImplicit();
     }
     Alloc->setParams(ParamDecls);
+    return Alloc;
+  };
 
+  FunctionDecl *Alloc = CreateAllocationFunctionDecl();
+  if (LangOpts.CUDA)
+    Alloc->addAttr(CUDAHostAttr::CreateImplicit(Context));
   Context.getTranslationUnitDecl()->addDecl(Alloc);
   IdResolver.tryAddTopLevelDecl(Alloc, Name);
+
+  if (LangOpts.CUDA) {
+    Alloc = CreateAllocationFunctionDecl();
+    Alloc->addAttr(CUDADeviceAttr::CreateImplicit(Context));
+    Context.getTranslationUnitDecl()->addDecl(Alloc);
+    IdResolver.tryAddTopLevelDecl(Alloc, Name);
+  }
 }
 
 FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc,
                                                   bool CanProvideSize,
                                                   bool Overaligned,
                                                   DeclarationName Name) {
   DeclareGlobalNewDelete();