[OpenCL] Supports optional same image reads and writes in C++ for OpenCL 2021

[Topotuna]

Summary

Adds support for a feature macro __opencl_c_read_write_images in
C++ for OpenCL 2021 enabling a respective optional core feature
from OpenCL 3.0.

This change aims to achieve compatibility between C++ for OpenCL
2021 and OpenCL 3.0.

[Anastasia]

LGTM! Thanks

clang/lib/Sema/SemaDeclAttr.cpp

static void handleOpenCLAccessAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 
   // OpenCL v2.0 s6.6 - read_write can be used for image types to specify that
   // an image object can be read and written. OpenCL v2.0 s6.13.6 - A kernel
   // cannot read from and write to the same pipe object. Using the read_write
   // (or __read_write) qualifier with the pipe qualifier is a compilation error.
   // OpenCL v3.0 s6.8 - For OpenCL C 2.0, or with the
   // __opencl_c_read_write_images feature, image objects specified as arguments
   // to a kernel can additionally be declared to be read-write.
-  // C++ for OpenCL inherits rule from OpenCL C v2.0.
+  // C++ for OpenCL 1.0 inherits rule from OpenCL C v2.0.
+  // C++ for OpenCL 2021 inherits rule from OpenCL C v3.0.
   if (const auto *PDecl = dyn_cast<ParmVarDecl>(D)) {
     const Type *DeclTy = PDecl->getType().getCanonicalType().getTypePtr();
     if (AL.getAttrName()->getName().find("read_write") != StringRef::npos) {
-      bool ReadWriteImagesUnsupportedForOCLC =
-          (S.getLangOpts().OpenCLVersion < 200) ||
-          (S.getLangOpts().OpenCLVersion == 300 &&
+      bool ReadWriteImagesUnsupported =
+          (S.getLangOpts().getOpenCLCompatibleVersion() < 200) ||
+          (S.getLangOpts().getOpenCLCompatibleVersion() == 300 &&
            !S.getOpenCLOptions().isSupported("__opencl_c_read_write_images",
                                              S.getLangOpts()));
-      if ((!S.getLangOpts().OpenCLCPlusPlus &&
-           ReadWriteImagesUnsupportedForOCLC) ||
-          DeclTy->isPipeType()) {
+      if (ReadWriteImagesUnsupported || DeclTy->isPipeType()) {
         S.Diag(AL.getLoc(), diag::err_opencl_invalid_read_write)
             << AL << PDecl->getType() << DeclTy->isImageType();
         D->setInvalidDecl(true);
         return;
       }
     }
   }
 

clang/test/Misc/opencl-c-3.0.incorrect_options.cl

 // RUN: not %clang_cc1 -cl-std=CL3.0 -triple spir-unknown-unknown -cl-ext=-__opencl_c_fp64,+cl_khr_fp64 %s 2>&1 | FileCheck -check-prefix=CHECK-FP64 %s
 // RUN: not %clang_cc1 -cl-std=CL3.0 -triple spir-unknown-unknown -cl-ext=+__opencl_c_fp64,-cl_khr_fp64 %s 2>&1 | FileCheck -check-prefix=CHECK-FP64 %s
 // RUN: not %clang_cc1 -cl-std=clc++2021 -triple spir-unknown-unknown -cl-ext=-__opencl_c_fp64,+cl_khr_fp64 %s 2>&1 | FileCheck -check-prefix=CHECK-FP64 %s
 // RUN: not %clang_cc1 -cl-std=clc++2021 -triple spir-unknown-unknown -cl-ext=+__opencl_c_fp64,-cl_khr_fp64 %s 2>&1 | FileCheck -check-prefix=CHECK-FP64 %s
 // RUN: not %clang_cc1 -cl-std=CL3.0 -triple spir-unknown-unknown -cl-ext=+__opencl_c_read_write_images,-__opencl_c_images %s 2>&1 | FileCheck -check-prefix=CHECK-READ-WRITE-IMAGES %s
+// RUN: not %clang_cc1 -cl-std=clc++2021 -triple spir-unknown-unknown -cl-ext=+__opencl_c_read_write_images,-__opencl_c_images %s 2>&1 | FileCheck -check-prefix=CHECK-READ-WRITE-IMAGES %s
 // RUN: not %clang_cc1 -cl-std=CL3.0 -triple spir-unknown-unknown -cl-ext=+__opencl_c_pipes,-__opencl_c_generic_address_space %s 2>&1 | FileCheck -check-prefix=CHECK-PIPES %s
 // RUN: not %clang_cc1 -cl-std=clc++2021 -triple spir-unknown-unknown -cl-ext=+__opencl_c_pipes,-__opencl_c_generic_address_space %s 2>&1 | FileCheck -check-prefix=CHECK-PIPES %s
 // RUN: not %clang_cc1 -cl-std=CL3.0 -triple spir-unknown-unknown -cl-ext=+__opencl_c_3d_image_writes,+__opencl_c_images,-cl_khr_3d_image_writes %s 2>&1 | FileCheck -check-prefix=CHECK-3D-WRITE-IMAGES-DIFF %s
 // RUN: not %clang_cc1 -cl-std=CL3.0 -triple spir-unknown-unknown -cl-ext=+__opencl_c_3d_image_writes,-__opencl_c_images %s 2>&1 | FileCheck -check-prefix=CHECK-3D-WRITE-IMAGES-DEPS %s
 
 // CHECK-FP64: error: options cl_khr_fp64 and __opencl_c_fp64 are set to different values
 
 // CHECK-READ-WRITE-IMAGES: error: feature __opencl_c_read_write_images requires support of __opencl_c_images feature
 
 // CHECK-3D-WRITE-IMAGES-DIFF: options cl_khr_3d_image_writes and __opencl_c_3d_image_writes are set to different values
 // CHECK-3D-WRITE-IMAGES-DEPS: error: feature __opencl_c_3d_image_writes requires support of __opencl_c_images feature
 
 // CHECK-PIPES: error: feature __opencl_c_pipes requires support of __opencl_c_generic_address_space feature

clang/test/SemaOpenCL/access-qualifier.cl

 // RUN: %clang_cc1 -triple spir-unknown-unknown -verify -pedantic -fsyntax-only -cl-std=CL1.2 %s -cl-ext=-cl_khr_3d_image_writes
 // RUN: %clang_cc1 -triple spir-unknown-unknown -verify -pedantic -fsyntax-only -cl-std=CL2.0 %s
 // RUN: %clang_cc1 -triple spir-unknown-unknown -verify -pedantic -fsyntax-only -cl-std=CL3.0 %s
 // RUN: %clang_cc1 -triple spir-unknown-unknown -verify -pedantic -fsyntax-only -cl-std=CL3.0 %s -cl-ext=-__opencl_c_read_write_images
+// RUN: %clang_cc1 -triple spir-unknown-unknown -verify -pedantic -fsyntax-only -cl-std=clc++2021 %s
+// RUN: %clang_cc1 -triple spir-unknown-unknown -verify -pedantic -fsyntax-only -cl-std=clc++2021 %s -cl-ext=-__opencl_c_read_write_images
 
 typedef image1d_t img1d_ro_default; // expected-note {{previously declared 'read_only' here}}
 
 typedef write_only image1d_t img1d_wo; // expected-note {{previously declared 'write_only' here}}
 typedef read_only image1d_t img1d_ro;
 
-#if (__OPENCL_C_VERSION__ == 200) || (__OPENCL_C_VERSION__ == 300 && defined(__opencl_c_read_write_images))
+#if (__OPENCL_C_VERSION__ == 200) || ((__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300) && defined(__opencl_c_read_write_images))
 typedef read_write image1d_t img1d_rw;
 #endif
 
 typedef int Int;
 typedef read_only int IntRO; // expected-error {{access qualifier can only be used for pipe and image type}}
 
+void myWrite(write_only image1d_t);
+#if !defined(__OPENCL_CPP_VERSION__)
+// expected-note@-2 {{passing argument to parameter here}}
+// expected-note@-3 {{passing argument to parameter here}}
+#else
+// expected-note@-5 {{candidate function not viable: no known conversion from '__private img1d_ro' (aka '__private __read_only image1d_t') to '__private __write_only image1d_t' for 1st argument}}
+// expected-note@-6 {{candidate function not viable: no known conversion from '__private img1d_ro_default' (aka '__private __read_only image1d_t') to '__private __write_only image1d_t' for 1st argument}}
+#endif
 
-void myWrite(write_only image1d_t); // expected-note {{passing argument to parameter here}} expected-note {{passing argument to parameter here}}
-void myRead(read_only image1d_t); // expected-note {{passing argument to parameter here}}
+void myRead(read_only image1d_t);
+#if !defined(__OPENCL_CPP_VERSION__)
+// expected-note@-2 {{passing argument to parameter here}}
+#else
+// expected-note@-4 {{candidate function not viable: no known conversion from '__private img1d_wo' (aka '__private __write_only image1d_t') to '__private __read_only image1d_t' for 1st argument}}
+#endif
 
-#if (__OPENCL_C_VERSION__ == 200) || (__OPENCL_C_VERSION__ == 300 && defined(__opencl_c_read_write_images))
+#if (__OPENCL_C_VERSION__ == 200) || ((__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300) && defined(__opencl_c_read_write_images))
 void myReadWrite(read_write image1d_t);
 #else
 void myReadWrite(read_write image1d_t); // expected-error {{access qualifier 'read_write' can not be used for '__read_write image1d_t' prior to OpenCL C version 2.0 or in version 3.0 and without __opencl_c_read_write_images feature}}
 #endif
 
 
 kernel void k1(img1d_wo img) {
-  myRead(img); // expected-error {{passing '__private img1d_wo' (aka '__private __write_only image1d_t') to parameter of incompatible type '__read_only image1d_t'}}
+  myRead(img);
+#if !defined(__OPENCL_CPP_VERSION__)
+// expected-error@-2 {{passing '__private img1d_wo' (aka '__private __write_only image1d_t') to parameter of incompatible type '__read_only image1d_t'}}
+#else
+// expected-error@-4 {{no matching function for call to 'myRead'}}
+#endif
 }
 
 kernel void k2(img1d_ro img) {
-  myWrite(img); // expected-error {{passing '__private img1d_ro' (aka '__private __read_only image1d_t') to parameter of incompatible type '__write_only image1d_t'}}
+  myWrite(img);
+#if !defined(__OPENCL_CPP_VERSION__)
+// expected-error@-2 {{passing '__private img1d_ro' (aka '__private __read_only image1d_t') to parameter of incompatible type '__write_only image1d_t'}}
+#else
+// expected-error@-4 {{no matching function for call to 'myWrite'}}
+#endif
 }
 
 kernel void k3(img1d_wo img) {
   myWrite(img);
 }
 
-#if (__OPENCL_C_VERSION__ == 200) || (__OPENCL_C_VERSION__ == 300 && defined(__opencl_c_read_write_images))
+#if (__OPENCL_C_VERSION__ == 200) || ((__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300) && defined(__opencl_c_read_write_images))
 kernel void k4(img1d_rw img) {
   myReadWrite(img);
 }
 #endif
 
 kernel void k5(img1d_ro_default img) {
-  myWrite(img); // expected-error {{passing '__private img1d_ro_default' (aka '__private __read_only image1d_t') to parameter of incompatible type '__write_only image1d_t'}}
+  myWrite(img);
+#if !defined(__OPENCL_CPP_VERSION__)
+// expected-error@-2 {{passing '__private img1d_ro_default' (aka '__private __read_only image1d_t') to parameter of incompatible type '__write_only image1d_t'}}
+#else
+// expected-error@-4 {{no matching function for call to 'myWrite'}}
+#endif
 }
 
 kernel void k6(img1d_ro img) {
   myRead(img);
 }
 
 kernel void k7(read_only img1d_wo img){} // expected-error {{multiple access qualifiers}}
 
 kernel void k8(write_only img1d_ro_default img){} // expected-error {{multiple access qualifiers}}
 
 kernel void k9(read_only int i){} // expected-error{{access qualifier can only be used for pipe and image type}}
 
 kernel void k10(read_only Int img){} // expected-error {{access qualifier can only be used for pipe and image type}}
 
 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-warning {{duplicate 'read_only' declaration specifier}}
 
-#if (__OPENCL_C_VERSION__ == 200) || (__OPENCL_C_VERSION__ == 300 && defined(__opencl_c_read_write_images))
+#if (__OPENCL_C_VERSION__ == 200) || ((__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300) && defined(__opencl_c_read_write_images))
 kernel void k13(read_write pipe int i){} // expected-error{{access qualifier 'read_write' can not be used for 'read_only pipe int'}}
 #else
 kernel void k13(__read_write image1d_t i){} // expected-error{{access qualifier '__read_write' can not be used for '__read_write image1d_t' prior to OpenCL C version 2.0 or in version 3.0 and without __opencl_c_read_write_images feature}}
 #endif
 
-#if __OPENCL_C_VERSION__ < 200
+#if defined(__OPENCL_C_VERSION__) && __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 support}}
 #endif
 
-#if (__OPENCL_C_VERSION__ == 200) || (__OPENCL_C_VERSION__ == 300 && defined(__opencl_c_read_write_images))
+#if (__OPENCL_C_VERSION__ == 200) || ((__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300) && defined(__opencl_c_read_write_images))
 kernel void read_write_twice_typedef(read_write img1d_rw i){} // expected-warning {{duplicate 'read_write' declaration specifier}}
-// expected-note@-67 {{previously declared 'read_write' here}}
+// expected-note@-95 {{previously declared 'read_write' here}}
 #endif
 
 #if __OPENCL_C_VERSION__ >= 200
 void myPipeWrite(write_only pipe int); // expected-note {{passing argument to parameter here}}
 kernel void k14(read_only pipe int p) {
   myPipeWrite(p); // expected-error {{passing '__private read_only pipe int' to parameter of incompatible type 'write_only pipe int'}}
 }
 
 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 '__private ROPipeInt' (aka '__private read_only pipe int') to parameter of incompatible type 'write_only pipe int'}}
   // expected-note@-16 {{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}}
+// expected-note@-123 {{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}}
+// expected-note@-129 {{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}}
-
+// expected-note@-131 {{previously declared 'write_only' here}}