[OpenCL] Support -fdeclare-opencl-builtins in C++ mode

Support for C++ mode was accidentally lacking due to not checking the
OpenCLCPlusPlus LangOpts version.

Differential Revision: https://reviews.llvm.org/D69233

Author: svenvh

clang/lib/Sema/SemaLookup.cpp

@@ -765,10 +765,13 @@ static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR,
     ASTContext &Context = S.Context;
 
     // Ignore this BIF if its version does not match the language options.
-    if (Context.getLangOpts().OpenCLVersion < OpenCLBuiltin.MinVersion)
+    unsigned OpenCLVersion = Context.getLangOpts().OpenCLVersion;
+    if (Context.getLangOpts().OpenCLCPlusPlus)
+      OpenCLVersion = 200;
+    if (OpenCLVersion < OpenCLBuiltin.MinVersion)
       continue;
     if ((OpenCLBuiltin.MaxVersion != 0) &&
-        (Context.getLangOpts().OpenCLVersion >= OpenCLBuiltin.MaxVersion))
+        (OpenCLVersion >= OpenCLBuiltin.MaxVersion))
       continue;
 
     SmallVector<QualType, 1> RetTypes;

clang/test/SemaOpenCL/fdeclare-opencl-builtins.cl

@@ -4,8 +4,10 @@
 // RUN: %clang_cc1 %s -triple spir -verify -pedantic -Wconversion -Werror -fsyntax-only -cl-std=CL1.2 -fdeclare-opencl-builtins -finclude-default-header
 // RUN: %clang_cc1 %s -triple spir -verify -pedantic -Wconversion -Werror -fsyntax-only -cl-std=CL2.0 -fdeclare-opencl-builtins -DNO_HEADER
 // RUN: %clang_cc1 %s -triple spir -verify -pedantic -Wconversion -Werror -fsyntax-only -cl-std=CL2.0 -fdeclare-opencl-builtins -finclude-default-header
+// RUN: %clang_cc1 %s -triple spir -verify -pedantic -Wconversion -Werror -fsyntax-only -cl-std=CLC++ -fdeclare-opencl-builtins -DNO_HEADER
+// RUN: %clang_cc1 %s -triple spir -verify -pedantic -Wconversion -Werror -fsyntax-only -cl-std=CLC++ -fdeclare-opencl-builtins -finclude-default-header
 
-#if __OPENCL_C_VERSION__ >= CL_VERSION_2_0
+#if defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ >= CL_VERSION_2_0
 // expected-no-diagnostics
 #endif
 
@@ -97,7 +99,7 @@ kernel void basic_image_writeonly(write_only image1d_buffer_t image_write_only_i
 
 kernel void basic_subgroup(global uint *out) {
   out[0] = get_sub_group_size();
-#if __OPENCL_C_VERSION__ < CL_VERSION_2_0
+#if !defined(__OPENCL_CPP_VERSION__) && __OPENCL_C_VERSION__ < CL_VERSION_2_0
 // expected-error@-2{{implicit declaration of function 'get_sub_group_size' is invalid in OpenCL}}
 // expected-error@-3{{implicit conversion changes signedness: 'int' to 'uint' (aka 'unsigned int')}}
 #endif
@@ -130,7 +132,7 @@ kernel void basic_work_item() {
   uint ui;
 
   get_enqueued_local_size(ui);
-#if __OPENCL_C_VERSION__ < CL_VERSION_2_0
+#if !defined(__OPENCL_CPP_VERSION__) && __OPENCL_C_VERSION__ < CL_VERSION_2_0
 // expected-error@-2{{implicit declaration of function 'get_enqueued_local_size' is invalid in OpenCL}}
 #endif
 }