[LLVM-C] Add Bindings to Access an Instruction's DebugLoc

[CodaFi]

Summary

Provide direct accessors to supplement LLVMSetInstDebugLocation. In addition, properly accept and return the NULL location. The old accessors provided no way to do this, so the current debug location cannot currently be cleared.

[CodaFi]

Correctly handle the NULL location

[whitequark]

llvm/include/llvm-c/DebugInfo.h

1206

What does "consumed" mean here exactly? Aren't metadata owned by the context anyway?

[CodaFi]

llvm/include/llvm-c/DebugInfo.h

1206

Whoops, I read the std::move in the accessor and figured it would steal the data from the tracking ref. But it appears that is not the case. I'll update this.

[whitequark]

LGTM

llvm/include/llvm-c/DebugInfo.h

 /**
  * Set the subprogram attached to a function.
  *
  * @see llvm::Function::setSubprogram()
  */
 void LLVMSetSubprogram(LLVMValueRef Func, LLVMMetadataRef SP);
 
 /**
+ * Get the debug location for the given instruction.
+ *
+ * @see llvm::Instruction::getDebugLoc()
+ */
+LLVMMetadataRef LLVMInstructionGetDebugLoc(LLVMValueRef Inst);
+
+/**
+ * Set the debug location for the given instruction.
+ *
+ * The debug location is consumed by this function.
+ *
+ * @see llvm::Instruction::setDebugLoc()
+ */
+void LLVMInstructionSetDebugLoc(LLVMValueRef Inst, LLVMMetadataRef Loc);
+
+/**
  * Obtain the enumerated type of a Metadata instance.
  *
  * @see llvm::Metadata::getMetadataID()
  */
 LLVMMetadataKind LLVMGetMetadataKind(LLVMMetadataRef Metadata);
 
 #ifdef __cplusplus
 } /* end extern "C" */
 #endif
 
 #endif

llvm/lib/IR/DebugInfo.cpp

 LLVMMetadataRef LLVMGetSubprogram(LLVMValueRef Func) {
   return wrap(unwrap<Function>(Func)->getSubprogram());
 }
 
 void LLVMSetSubprogram(LLVMValueRef Func, LLVMMetadataRef SP) {
   unwrap<Function>(Func)->setSubprogram(unwrap<DISubprogram>(SP));
 }
 
+LLVMMetadataRef LLVMInstructionGetDebugLoc(LLVMValueRef Inst) {
+  return wrap(unwrap<Instruction>(Inst)->getDebugLoc().getAsMDNode());
+}
+
+void LLVMInstructionSetDebugLoc(LLVMValueRef Inst, LLVMMetadataRef Loc) {
+  unwrap<Instruction>(Inst)->setDebugLoc(DebugLoc(unwrapDI<MDNode>(Loc)));
+}
+
 LLVMMetadataKind LLVMGetMetadataKind(LLVMMetadataRef Metadata) {
   switch(unwrap(Metadata)->getMetadataID()) {
 #define HANDLE_METADATA_LEAF(CLASS) \
   case Metadata::CLASS##Kind: \
     return (LLVMMetadataKind)LLVM##CLASS##MetadataKind;
 #include "llvm/IR/Metadata.def"
   default:
     return (LLVMMetadataKind)LLVMGenericDINodeMetadataKind;
   }
 }