[OpenCL] Relax diagnostics on OpenCL access qualifiers

Summary:
Emit warning for multiple access qualifiers if they do not conflict.

Patch by Alexey Bader

Reviewers: Anastasia, yaxunl

Reviewed By: Anastasia

Subscribers: asavonic, bader, cfe-commits

Differential Revision: https://reviews.llvm.org/D51302

llvm-svn: 341553

clang/lib/Sema/SemaDeclAttr.cpp

@@ -5900,10 +5900,16 @@ static void handleOpenCLAccessAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 
   // Check if there is only one access qualifier.
   if (D->hasAttr<OpenCLAccessAttr>()) {
-    S.Diag(AL.getLoc(), diag::err_opencl_multiple_access_qualifiers)
-        << D->getSourceRange();
-    D->setInvalidDecl(true);
-    return;
+    if (D->getAttr<OpenCLAccessAttr>()->getSemanticSpelling() ==
+        AL.getSemanticSpelling()) {
+      S.Diag(AL.getLoc(), diag::warn_duplicate_declspec)
+          << AL.getName()->getName() << AL.getRange();
+    } else {
+      S.Diag(AL.getLoc(), diag::err_opencl_multiple_access_qualifiers)
+          << D->getSourceRange();
+      D->setInvalidDecl(true);
+      return;
+    }
   }
 
   // OpenCL v2.0 s6.6 - read_write can be used for image types to specify that an

clang/lib/Sema/SemaType.cpp

@@ -7105,23 +7105,43 @@ static void HandleOpenCLAccessAttr(QualType &CurType, const ParsedAttr &Attr,
   }
 
   if (const TypedefType* TypedefTy = CurType->getAs<TypedefType>()) {
-    QualType PointeeTy = TypedefTy->desugar();
-    S.Diag(Attr.getLoc(), diag::err_opencl_multiple_access_qualifiers);
+    QualType BaseTy = TypedefTy->desugar();
 
     std::string PrevAccessQual;
-    switch (cast<BuiltinType>(PointeeTy.getTypePtr())->getKind()) {
-      #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
-    case BuiltinType::Id:                                          \
-      PrevAccessQual = #Access;                                    \
-      break;
-      #include "clang/Basic/OpenCLImageTypes.def"
-    default:
-      assert(0 && "Unable to find corresponding image type.");
+    if (BaseTy->isPipeType()) {
+      if (TypedefTy->getDecl()->hasAttr<OpenCLAccessAttr>()) {
+        OpenCLAccessAttr *Attr =
+            TypedefTy->getDecl()->getAttr<OpenCLAccessAttr>();
+        PrevAccessQual = Attr->getSpelling();
+      } else {
+        PrevAccessQual = "read_only";
+      }
+    } else if (const BuiltinType* ImgType = BaseTy->getAs<BuiltinType>()) {
+
+      switch (ImgType->getKind()) {
+        #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
+      case BuiltinType::Id:                                          \
+        PrevAccessQual = #Access;                                    \
+        break;
+        #include "clang/Basic/OpenCLImageTypes.def"
+      default:
+        llvm_unreachable("Unable to find corresponding image type.");
+      }
+    } else {
+      llvm_unreachable("unexpected type");
+    }
+    StringRef AttrName = Attr.getName()->getName();
+    if (PrevAccessQual == AttrName.ltrim("_")) {
+      // Duplicated qualifiers
+      S.Diag(Attr.getLoc(), diag::warn_duplicate_declspec)
+         << AttrName << Attr.getRange();
+    } else {
+      // Contradicting qualifiers
+      S.Diag(Attr.getLoc(), diag::err_opencl_multiple_access_qualifiers);
     }
 
     S.Diag(TypedefTy->getDecl()->getBeginLoc(),
-           diag::note_opencl_typedef_access_qualifier)
-        << PrevAccessQual;
+           diag::note_opencl_typedef_access_qualifier) << PrevAccessQual;
   } else if (CurType->isPipeType()) {
     if (Attr.getSemanticSpelling() == OpenCLAccessAttr::Keyword_write_only) {
       QualType ElemType = CurType->getAs<PipeType>()->getElementType();

clang/test/SemaOpenCL/access-qualifier.cl

@@ -60,7 +60,7 @@ kernel void k10(read_only Int img){} // expected-error {{access qualifier can on
 
 kernel void k11(read_only write_only image1d_t i){} // expected-error{{multiple access qualifiers}}
 
-kernel void k12(read_only read_only image1d_t i){} // expected-error{{multiple access qualifiers}}
+kernel void k12(read_only read_only image1d_t i){} // expected-warning {{duplicate 'read_only' declaration specifier}}
 
 #if __OPENCL_C_VERSION__ >= 200
 kernel void k13(read_write pipe int i){} // expected-error{{access qualifier 'read_write' can not be used for 'read_only pipe int'}}
@@ -78,3 +78,33 @@ kernel void k14(read_only pipe int p) {
 #if __OPENCL_C_VERSION__ < 200
 kernel void test_image3d_wo(write_only image3d_t img) {} // expected-error {{use of type '__write_only image3d_t' requires cl_khr_3d_image_writes extension to be enabled}}
 #endif
+
+#if __OPENCL_C_VERSION__ >= 200
+kernel void read_write_twice_typedef(read_write img1d_rw i){} // expected-warning {{duplicate 'read_write' declaration specifier}}
+// expected-note@-74 {{previously declared 'read_write' here}}
+
+kernel void pipe_ro_twice(read_only read_only pipe int i){} // expected-warning{{duplicate 'read_only' declaration specifier}}
+// Conflicting access qualifiers
+kernel void pipe_ro_twice_tw(read_write read_only read_only pipe int i){} // expected-error{{access qualifier 'read_write' can not be used for 'read_only pipe int'}}
+kernel void pipe_ro_wo(read_only write_only pipe int i){} // expected-error{{multiple access qualifiers}}
+
+typedef read_only pipe int ROPipeInt;
+kernel void pipe_ro_twice_typedef(read_only ROPipeInt i){} // expected-warning{{duplicate 'read_only' declaration specifier}}
+// expected-note@-2 {{previously declared 'read_only' here}}
+
+kernel void pass_ro_typedef_to_wo(ROPipeInt p) {
+  myPipeWrite(p); // expected-error {{passing 'ROPipeInt' (aka 'read_only pipe int') to parameter of incompatible type 'write_only pipe int'}}
+  // expected-note@-25 {{passing argument to parameter here}}
+}
+#endif
+
+kernel void read_only_twice_typedef(__read_only img1d_ro i){} // expected-warning {{duplicate '__read_only' declaration specifier}}
+// expected-note@-95 {{previously declared 'read_only' here}}
+
+kernel void read_only_twice_default(read_only img1d_ro_default img){} // expected-warning {{duplicate 'read_only' declaration specifier}}
+// expected-note@-101 {{previously declared 'read_only' here}}
+
+kernel void image_wo_twice(write_only __write_only image1d_t i){} // expected-warning {{duplicate '__write_only' declaration specifier}}
+kernel void image_wo_twice_typedef(write_only img1d_wo i){} // expected-warning {{duplicate 'write_only' declaration specifier}}
+// expected-note@-103 {{previously declared 'write_only' here}}
+