[CUDA] Allow trivial constructors as initializer for __shared__ variables.

Differential Revision: http://reviews.llvm.org/D12739

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247307 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CodeGenModule.cpp

@@ -2165,8 +2165,10 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
   if (getLangOpts().CPlusPlus && getLangOpts().CUDAIsDevice
       && D->hasAttr<CUDASharedAttr>()) {
     if (InitExpr) {
-      Error(D->getLocation(),
-            "__shared__ variable cannot have an initialization.");
+      const auto *C = dyn_cast<CXXConstructExpr>(InitExpr);
+      if (C == nullptr || !C->getConstructor()->hasTrivialBody())
+        Error(D->getLocation(),
+              "__shared__ variable cannot have an initialization.");
     }
     Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
   } else if (!InitExpr) {

test/CodeGenCUDA/address-spaces.cu

@@ -25,6 +25,8 @@ struct MyStruct {
 // CHECK: @_ZZ5func3vE1a = internal addrspace(3) global float 0.000000e+00
 // CHECK: @_ZZ5func4vE1a = internal addrspace(3) global float 0.000000e+00
 // CHECK: @b = addrspace(3) global float undef
+// CHECK: @c = addrspace(3) global %struct.c undef
+// CHECK  @d = addrspace(3) global %struct.d undef
 
 __device__ void foo() {
   // CHECK: load i32, i32* addrspacecast (i32 addrspace(1)* @i to i32*)
@@ -117,3 +119,15 @@ __device__ int construct_shared_struct() {
   return t.getData();
 // CHECK: call i32 @_ZN14StructWithCtor7getDataEv(%struct.StructWithCtor* addrspacecast (%struct.StructWithCtor addrspace(3)* @_ZZ23construct_shared_structvE1t to %struct.StructWithCtor*))
 }
+
+// Make sure we allow __shared__ structures with default or empty constructors.
+struct c {
+  int i;
+};
+__shared__ struct c c;
+
+struct d {
+  int i;
+  d() {}
+};
+__shared__ struct d d;