[LLVM-C] Add Accessors for Discarding Value Names in the IR

[CodaFi]

Summary

Add accessors so the performance improvement from this setting is accessible to third parties.

[whitequark]

LGTM

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

  * Set the yield callback function for this context.
  *
  * @see LLVMContext::setYieldCallback()
  */
 void LLVMContextSetYieldCallback(LLVMContextRef C, LLVMYieldCallback Callback,
                                  void *OpaqueHandle);
 
 /**
+ * Retrieve whether the given context is set to discard all value names.
+ *
+ * @see LLVMContext::shouldDiscardValueNames()
+ */
+bool LLVMContextShouldDiscardValueNames(LLVMContextRef C);
+
+/**
+ * Set whether the given context discards all value names.
+ *
+ * If true, only the names of GlobalValue objects will be available in the IR.
+ * This can be used to save memory and runtime, especially in release mode.
+ *
+ * @see LLVMContext::setDiscardValueNames()
+ */
+void LLVMContextSetDiscardValueNames(LLVMContextRef C, bool Discard);
+
+/**
  * Destroy a context instance.
  *
  * This should be called for every call to LLVMContextCreate() or memory
  * will be leaked.
  */
 void LLVMContextDispose(LLVMContextRef C);
 
 /**

llvm/trunk/lib/IR/Core.cpp

 
 void LLVMContextSetYieldCallback(LLVMContextRef C, LLVMYieldCallback Callback,
                                  void *OpaqueHandle) {
   auto YieldCallback =
     LLVM_EXTENSION reinterpret_cast<LLVMContext::YieldCallbackTy>(Callback);
   unwrap(C)->setYieldCallback(YieldCallback, OpaqueHandle);
 }
 
+bool LLVMContextShouldDiscardValueNames(LLVMContextRef C) {
+  return unwrap(C)->shouldDiscardValueNames();
+}
+
+void LLVMContextSetDiscardValueNames(LLVMContextRef C, bool Discard) {
+  unwrap(C)->setDiscardValueNames(Discard);
+}
+
 void LLVMContextDispose(LLVMContextRef C) {
   delete unwrap(C);
 }
 
 unsigned LLVMGetMDKindIDInContext(LLVMContextRef C, const char *Name,
                                   unsigned SLen) {
   return unwrap(C)->getMDKindID(StringRef(Name, SLen));
 }