[C++4OpenCL] NULL redefined as nullptr

[Topotuna]

Summary

Redefines NULL as nullptr instead of ((void*)0) in C++ for OpenCL.

Such internal representation of NULL provides compatibility with
C++11 and later language standards.

Fixes llvm.org/PR48098

[Anastasia]

clang/test/SemaOpenCL/null_literal.cl

2

I think these lines here are from another patch.

13

hmm, you should not get those errors though https://godbolt.org/z/qvr7x11TM

[Topotuna]

Patch made compatible with changes to D105988

[Topotuna]

clang/test/SemaOpenCL/null_literal.cl

13

The expected-error here refers to line 15 which displays an error: https://godbolt.org/z/zYzGedzv4

[Anastasia]

clang/test/SemaOpenCL/null_literal.cl

13

Makes sense. Sorry I didn't notice.

26

while we are at it, do you mind changing this check into

__OPENCL_CPP_VERSION__ == 200

and then we can remove -DCL20 from the run line

[Topotuna]

Separate NFC performed in D106254

[Topotuna]

clang/test/SemaOpenCL/null_literal.cl

26

Done in a separate patch D106254 because it is unrelated to this change.

[Anastasia]

LGTM! Thanks

clang/lib/Headers/opencl-c-base.h

 #endif
 typedef double double2 __attribute__((ext_vector_type(2)));
 typedef double double3 __attribute__((ext_vector_type(3)));
 typedef double double4 __attribute__((ext_vector_type(4)));
 typedef double double8 __attribute__((ext_vector_type(8)));
 typedef double double16 __attribute__((ext_vector_type(16)));
 #endif
 
+#if defined(__OPENCL_CPP_VERSION__)
+#define NULL nullptr
+#elif defined(__OPENCL_C_VERSION__)
 #define NULL ((void*)0)
+#endif
 
 /**
  * Value of maximum non-infinite single-precision floating-point
  * number.
  */
 #define MAXFLOAT 0x1.fffffep127f
 
 /**

clang/test/SemaOpenCL/null_literal.cl

 // RUN: %clang_cc1 -fdeclare-opencl-builtins -finclude-default-header -verify %s
 // RUN: %clang_cc1 -cl-std=CL1.0 -fdeclare-opencl-builtins -finclude-default-header -verify %s
 // RUN: %clang_cc1 -cl-std=CL1.1 -fdeclare-opencl-builtins -finclude-default-header -verify %s
 // RUN: %clang_cc1 -cl-std=CL1.2 -fdeclare-opencl-builtins -finclude-default-header -verify %s
 // RUN: %clang_cc1 -cl-std=CL2.0 -fdeclare-opencl-builtins -finclude-default-header -verify %s
+// RUN: %clang_cc1 -cl-std=clc++ -fdeclare-opencl-builtins -finclude-default-header -verify %s
 
 void foo(){
 
 global int* ptr1 = NULL;
 
+#if defined(__OPENCL_CPP_VERSION__)
+// expected-error@+2{{cannot initialize a variable of type '__global int *__private' with an rvalue of type '__global void *'}}
+#endif
 global int* ptr2 = (global void*)0;
 
 constant int* ptr3 = NULL;
 
-constant int* ptr4 = (global void*)0; // expected-error{{initializing '__constant int *__private' with an expression of type '__global void *' changes address space of pointer}}
+#if defined(__OPENCL_CPP_VERSION__)
+// expected-error@+4{{cannot initialize a variable of type '__constant int *__private' with an rvalue of type '__global void *'}}
+#else
+// expected-error@+2{{initializing '__constant int *__private' with an expression of type '__global void *' changes address space of pointer}}
+#endif
+constant int* ptr4 = (global void*)0;
 
 #if __OPENCL_C_VERSION__ == CL_VERSION_2_0
 // Accept explicitly pointer to generic address space in OpenCL v2.0.
 global int* ptr5 = (generic void*)0;
 #endif
 
-global int* ptr6 = (local void*)0; // expected-error{{initializing '__global int *__private' with an expression of type '__local void *' changes address space of pointer}}
+#if defined(__OPENCL_CPP_VERSION__)
+// expected-error@+4{{cannot initialize a variable of type '__global int *__private' with an rvalue of type '__local void *'}}
+#else
+// expected-error@+2{{initializing '__global int *__private' with an expression of type '__local void *' changes address space of pointer}}
+#endif
+global int* ptr6 = (local void*)0;
 
 bool cmp = ptr1 == NULL;
 
-cmp = ptr1 == (local void*)0; // expected-error{{comparison between  ('__global int *' and '__local void *') which are pointers to non-overlapping address spaces}}
+#if defined(__OPENCL_CPP_VERSION__)
+// expected-error@+4{{comparison of distinct pointer types ('__global int *' and '__local void *')}}
+#else
+// expected-error@+2{{comparison between  ('__global int *' and '__local void *') which are pointers to non-overlapping address spaces}}
+#endif
+cmp = ptr1 == (local void*)0;
 
 cmp = ptr3 == NULL;
 
 }