Add target triple normalization to the C API

[mhlindstr]

Summary

rL333307 was introduced to remove automatic target triple normalization when calling sys::getDefaultTargetTriple(), arguing that users of the latter already called Triple::normalize() if necessary. However, users of the C API currently have no way of doing target triple normalization. This patch introduces an LLVMNormalizeTargetTriple function to the C API which wraps Triple::normalize() and can be used on the result of LLVMGetDefaultTargetTriple to achieve the same effect.

[whitequark]

include/llvm-c/TargetMachine.h

142 ↗

(On Diff #155814)

This should take a const char *.

[mhlindstr]

Fixed the patch so that the LLVMNormalizeTargetTriple takes a const char* argument. Sorry about that.

[whitequark]

LGTM, thanks!

[mhlindstr]

I do not have write access to the repository, can someone else land this?

Thanks again!

llvm/trunk/include/llvm-c/TargetMachine.h

 LLVMBool LLVMTargetMachineEmitToMemoryBuffer(LLVMTargetMachineRef T, LLVMModuleRef M,
   LLVMCodeGenFileType codegen, char** ErrorMessage, LLVMMemoryBufferRef *OutMemBuf);
 
 /*===-- Triple ------------------------------------------------------------===*/
 /** Get a triple for the host machine as a string. The result needs to be
   disposed with LLVMDisposeMessage. */
 char* LLVMGetDefaultTargetTriple(void);
 
+/** Normalize a target triple. The result needs to be disposed with
+  LLVMDisposeMessage. */
+char* LLVMNormalizeTargetTriple(const char* triple);
+
 /** Get the host CPU as a string. The result needs to be disposed with
   LLVMDisposeMessage. */
 char* LLVMGetHostCPUName(void);
 
 /** Get the host CPU's features as a string. The result needs to be disposed
   with LLVMDisposeMessage. */
 char* LLVMGetHostCPUFeatures(void);
 
 /** Adds the target-specific analysis passes to the pass manager. */
 void LLVMAddAnalysisPasses(LLVMTargetMachineRef T, LLVMPassManagerRef PM);
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif

llvm/trunk/lib/Target/TargetMachineC.cpp

*OutMemBuf =
       LLVMCreateMemoryBufferWithMemoryRangeCopy(Data.data(), Data.size(), "");
   return Result;
 }
 
 char *LLVMGetDefaultTargetTriple(void) {
   return strdup(sys::getDefaultTargetTriple().c_str());
 }
 
+char *LLVMNormalizeTargetTriple(const char* triple) {
+  return strdup(Triple::normalize(StringRef(triple)).c_str());
+}
+
 char *LLVMGetHostCPUName(void) {
   return strdup(sys::getHostCPUName().data());
 }
 
 char *LLVMGetHostCPUFeatures(void) {
   SubtargetFeatures Features;
   StringMap<bool> HostFeatures;