OpenCL: disallow '#pragma OPENCL EXTENSION all : enable', per OpenCL 1.1 9.1

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141270 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Parse/ParsePragma.cpp

@@ -451,8 +451,11 @@ PragmaOpenCLExtensionHandler::HandlePragma(Preprocessor &PP,
   }
 
   OpenCLOptions &f = Actions.getOpenCLOptions();
-  if (ename->isStr("all")) {
-#define OPENCLEXT(nm)   f.nm = state;
+  // OpenCL 1.1 9.1: "The all variant sets the behavior for all extensions,
+  // overriding all previously issued extension directives, but only if the
+  // behavior is set to disable."
+  if (state == 0 && ename->isStr("all")) {
+#define OPENCLEXT(nm)   f.nm = 0;
 #include "clang/Basic/OpenCLExtensions.def"
   }
 #define OPENCLEXT(nm) else if (ename->isStr(#nm)) { f.nm = state; }

test/Parser/opencl-pragma.cl

@@ -4,6 +4,9 @@
 
 #pragma OPENCL EXTENSION cl_no_such_extension : disable /* expected-warning {{unknown OpenCL extension 'cl_no_such_extension' - ignoring}} */
 
+#pragma OPENCL EXTENSION all : disable
+#pragma OPENCL EXTENSION all : enable /* expected-warning {{unknown OpenCL extension 'all' - ignoring}} */
+
 #pragma OPENCL EXTENSION cl_khr_fp64 : on /* expected-warning {{expected 'enable' or 'disable' - ignoring}} */
 
 #pragma OPENCL FP_CONTRACT ON