[OpenCL] Diagnose scoped address-space qualified variables

Produce an error if variables qualified with a local or
a constant address space are not declared in the outermost
scope of a kernel.

Patch by Simon Perretta.

Differential Revision: https://reviews.llvm.org/D34024

llvm-svn: 305798

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -8311,6 +8311,9 @@ def err_opencl_ext_vector_component_invalid_length : Error<
   "vector component access has invalid length %0.  Supported: 1,2,3,4,8,16.">;
 def err_opencl_function_variable : Error<
   "%select{non-kernel function|function scope}0 variable cannot be declared in %1 address space">;
+def err_opencl_addrspace_scope : Error<
+  "variables in the %0 address space can only be declared in the outermost "
+  "scope of a kernel function">;
 def err_static_function_scope : Error<
   "variables in function scope cannot be declared static">;
 def err_opencl_bitfields : Error<

clang/lib/Sema/SemaDecl.cpp

@@ -7260,11 +7260,11 @@ void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
         NewVD->setInvalidDecl();
         return;
       }
-      // OpenCL v1.1 s6.5.2 and s6.5.3 no local or constant variables
-      // in functions.
       if (T.getAddressSpace() == LangAS::opencl_constant ||
           T.getAddressSpace() == LangAS::opencl_local) {
         FunctionDecl *FD = getCurFunctionDecl();
+        // OpenCL v1.1 s6.5.2 and s6.5.3: no local or constant variables
+        // in functions.
         if (FD && !FD->hasAttr<OpenCLKernelAttr>()) {
           if (T.getAddressSpace() == LangAS::opencl_constant)
             Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
@@ -7275,6 +7275,20 @@ void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
           NewVD->setInvalidDecl();
           return;
         }
+        // OpenCL v2.0 s6.5.2 and s6.5.3: local and constant variables must be
+        // in the outermost scope of a kernel function.
+        if (FD && FD->hasAttr<OpenCLKernelAttr>()) {
+          if (!getCurScope()->isFunctionScope()) {
+            if (T.getAddressSpace() == LangAS::opencl_constant)
+              Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
+                  << "constant";
+            else
+              Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
+                  << "local";
+            NewVD->setInvalidDecl();
+            return;
+          }
+        }
       } else if (T.getAddressSpace() != LangAS::Default) {
         // Do not allow other address spaces on automatic variable.
         Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 1;

clang/test/SemaOpenCL/storageclass.cl

@@ -13,6 +13,11 @@ void kernel foo(int x) {
   constant int L1 = 0;
   local int L2;
 
+  if (true) {
+    local int L1; // expected-error {{variables in the local address space can only be declared in the outermost scope of a kernel function}}
+    constant int L1 = 42; // expected-error {{variables in the constant address space can only be declared in the outermost scope of a kernel function}}
+  }
+
   auto int L3 = 7;                            // expected-error{{OpenCL version 1.2 does not support the 'auto' storage class specifier}}
   global int L4;                              // expected-error{{function scope variable cannot be declared in global address space}}
   __attribute__((address_space(100))) int L5; // expected-error{{automatic variable qualified with an invalid address space}}