From: Justin Lebar <jlebar@google.com>
Date: Fri, 30 Sep 2016 23:57:34 +0000 (+0000)
Subject: [CUDA] Disallow __constant__ local variables.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=682d473d4d784f32f657a141fad8640e6cb75278;p=clang

[CUDA] Disallow __constant__ local variables.

Reviewers: tra, rnk

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D25129

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@282986 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 66a5bce86c..eb8bf915e8 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -6723,6 +6723,7 @@ def err_cuda_vla : Error<
     "cannot use variable-length arrays in "
     "%select{__device__|__global__|__host__|__host__ __device__}0 functions">;
 def err_cuda_extern_shared : Error<"__shared__ variable %0 cannot be 'extern'">;
+def err_cuda_nonglobal_constant : Error<"__constant__ variables must be global">;
 
 def warn_non_pod_vararg_with_format_string : Warning<
   "cannot pass %select{non-POD|non-trivial}0 object of type %1 to variadic "
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index ff63d7b1ce..21cace432c 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -3696,6 +3696,19 @@ static void handleOptimizeNoneAttr(Sema &S, Decl *D,
     D->addAttr(Optnone);
 }
 
+static void handleConstantAttr(Sema &S, Decl *D, const AttributeList &Attr) {
+  if (checkAttrMutualExclusion<CUDASharedAttr>(S, D, Attr.getRange(),
+                                               Attr.getName()))
+    return;
+  auto *VD = cast<VarDecl>(D);
+  if (!VD->hasGlobalStorage()) {
+    S.Diag(Attr.getLoc(), diag::err_cuda_nonglobal_constant);
+    return;
+  }
+  D->addAttr(::new (S.Context) CUDAConstantAttr(
+      Attr.getRange(), S.Context, Attr.getAttributeSpellingListIndex()));
+}
+
 static void handleSharedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   if (checkAttrMutualExclusion<CUDAConstantAttr>(S, D, Attr.getRange(),
                                                  Attr.getName()))
@@ -5541,8 +5554,7 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
     handleCommonAttr(S, D, Attr);
     break;
   case AttributeList::AT_CUDAConstant:
-    handleSimpleAttributeWithExclusions<CUDAConstantAttr, CUDASharedAttr>(S, D,
-                                                                          Attr);
+    handleConstantAttr(S, D, Attr);
     break;
   case AttributeList::AT_PassObjectSize:
     handlePassObjectSizeAttr(S, D, Attr);
diff --git a/test/SemaCUDA/bad-attributes.cu b/test/SemaCUDA/bad-attributes.cu
index f3e1688462..4fb584aec4 100644
--- a/test/SemaCUDA/bad-attributes.cu
+++ b/test/SemaCUDA/bad-attributes.cu
@@ -61,3 +61,11 @@ __global__ static inline void foobar() {};
 #ifdef EXPECT_INLINE_WARNING
 // expected-warning@-2 {{ignored 'inline' attribute on kernel function 'foobar'}}
 #endif
+
+__constant__ int global_constant;
+void host_fn() {
+  __constant__ int c; // expected-error {{__constant__ variables must be global}}
+}
+__device__ void device_fn() {
+  __constant__ int c; // expected-error {{__constant__ variables must be global}}
+}