Fix compilation errors in C API when using C compiler

[benlangmuir]

Summary

Fix compilation errors when including C headers in C language mode instead of C++.

• Cannot use sizeof() on another union member
• nullptr vs NULL
• () vs (void)

Incidentally, fix an incorrect comment about memory ownership on the argument to __orc_rt_CreateCWrapperFunctionResultFromOutOfBandError, which is copied, not moved.

[lhames]

LGTM. Thanks Ben!

[benlangmuir]

2f53fcc831e2f5ceee0d42c41766d9231049e46b

compiler-rt/lib/orc/c_api.h

 #define ORC_RT_C_EXTERN_C_BEGIN ORC_RT_C_STRICT_PROTOTYPES_BEGIN
 #define ORC_RT_C_EXTERN_C_END ORC_RT_C_STRICT_PROTOTYPES_END
 #endif
 
 ORC_RT_C_EXTERN_C_BEGIN
 
 typedef union {
   char *ValuePtr;
-  char Value[sizeof(ValuePtr)];
+  char Value[sizeof(char *)];
 } __orc_rt_CWrapperFunctionResultDataUnion;
 
 /**
  * __orc_rt_CWrapperFunctionResult is a kind of C-SmallVector with an
  * out-of-band error state.
  *
  * If Size == 0 and Data.ValuePtr is non-zero then the value is in the
  * 'out-of-band error' state, and Data.ValuePtr points at a malloc-allocated,
__orc_rt_CreateCWrapperFunctionResultFromString(const char *Source) {
   return __orc_rt_CreateCWrapperFunctionResultFromRange(Source,
                                                         strlen(Source) + 1);
 }
 
 /**
  * Create an __orc_rt_CWrapperFunctionResult representing an out-of-band
  * error.
  *
- * This function takes ownership of the string argument which must have been
- * allocated with malloc.
+ * This function copies the input string. The client is responsible for freeing
+ * the ErrMsg arg.
  */
 static inline __orc_rt_CWrapperFunctionResult
 __orc_rt_CreateCWrapperFunctionResultFromOutOfBandError(const char *ErrMsg) {
   __orc_rt_CWrapperFunctionResult R;
   R.Size = 0;
   char *Tmp = (char *)malloc(strlen(ErrMsg) + 1);
   strcpy(Tmp, ErrMsg);
   R.Data.ValuePtr = Tmp;

 }
 
 /**
  * Get a pointer to the data contained in the given
  * __orc_rt_CWrapperFunctionResult.
  */
 static inline const char *
 __orc_rt_CWrapperFunctionResultData(const __orc_rt_CWrapperFunctionResult *R) {
-  assert((R->Size != 0 || R->Data.ValuePtr == nullptr) &&
+  assert((R->Size != 0 || R->Data.ValuePtr == NULL) &&
          "Cannot get data for out-of-band error value");
   return R->Size > sizeof(R->Data.Value) ? R->Data.ValuePtr : R->Data.Value;
 }
 
 /**
  * Safely get the size of the given __orc_rt_CWrapperFunctionResult.
  *
  * Asserts that we're not trying to access the size of an error value.
  */
 static inline size_t
 __orc_rt_CWrapperFunctionResultSize(const __orc_rt_CWrapperFunctionResult *R) {
-  assert((R->Size != 0 || R->Data.ValuePtr == nullptr) &&
+  assert((R->Size != 0 || R->Data.ValuePtr == NULL) &&
          "Cannot get size for out-of-band error value");
   return R->Size;
 }
 
 /**
  * Returns 1 if this value is equivalent to a value just initialized by
  * __orc_rt_CWrapperFunctionResultInit, 0 otherwise.
  */

llvm/include/llvm-c/Transforms/PassBuilder.h

 
 /**
  * Create a new set of options for a PassBuilder
  *
  * Ownership of the returned instance is given to the client, and they are
  * responsible for it. The client should call LLVMDisposePassBuilderOptions
  * to free the pass builder options.
  */
-LLVMPassBuilderOptionsRef LLVMCreatePassBuilderOptions();
+LLVMPassBuilderOptionsRef LLVMCreatePassBuilderOptions(void);
 
 /**
  * Toggle adding the VerifierPass for the PassBuilder, ensuring all functions
  * inside the module is valid.
  */
 void LLVMPassBuilderOptionsSetVerifyEach(LLVMPassBuilderOptionsRef Options,
                                          LLVMBool VerifyEach);