Add binding for counting argument and find called value of call and invoke instruction from the C API.

Summary: As per title. This remove the need to rely on internal knowledge of call and invoke instruction to find called value and argument count.

Reviewers: bogner, chandlerc, echristo, dblaikie, joker.eph, Wallbraker

Differential Revision: http://reviews.llvm.org/D17054

llvm-svn: 260332

Author: deadalnix

llvm/include/llvm-c/Core.h

@@ -2385,6 +2385,17 @@ LLVMValueRef LLVMInstructionClone(LLVMValueRef Inst);
  * @{
  */
 
+/**
+ * Obtain the argument count for a call instruction.
+ *
+ * This expects an LLVMValueRef that corresponds to a llvm::CallInst or
+ * llvm::InvokeInst.
+ *
+ * @see llvm::CallInst::getNumArgOperands()
+ * @see llvm::InvokeInst::getNumArgOperands()
+ */
+unsigned LLVMGetNumArgOperands(LLVMValueRef Instr);
+
 /**
  * Set the calling convention for a call instruction.
  *
@@ -2413,6 +2424,17 @@ void LLVMRemoveInstrAttribute(LLVMValueRef Instr, unsigned index,
 void LLVMSetInstrParamAlignment(LLVMValueRef Instr, unsigned index,
                                 unsigned align);
 
+/**
+ * Obtain the pointer to the function invoked by this instruction.
+ *
+ * This expects an LLVMValueRef that corresponds to a llvm::CallInst or
+ * llvm::InvokeInst.
+ *
+ * @see llvm::CallInst::getCalledValue()
+ * @see llvm::InvokeInst::getCalledValue()
+ */
+LLVMValueRef LLVMGetCalledValue(LLVMValueRef Instr);
+
 /**
  * Obtain whether a call instruction is a tail call.
  *

llvm/lib/IR/Core.cpp

@@ -2041,22 +2041,17 @@ LLVMValueRef LLVMInstructionClone(LLVMValueRef Inst) {
 
 /*--.. Call and invoke instructions ........................................--*/
 
+unsigned LLVMGetNumArgOperands(LLVMValueRef Instr) {
+  return CallSite(unwrap<Instruction>(Instr)).getNumArgOperands();
+}
+
 unsigned LLVMGetInstructionCallConv(LLVMValueRef Instr) {
-  Value *V = unwrap(Instr);
-  if (CallInst *CI = dyn_cast<CallInst>(V))
-    return CI->getCallingConv();
-  if (InvokeInst *II = dyn_cast<InvokeInst>(V))
-    return II->getCallingConv();
-  llvm_unreachable("LLVMGetInstructionCallConv applies only to call and invoke!");
+  return CallSite(unwrap<Instruction>(Instr)).getCallingConv();
 }
 
 void LLVMSetInstructionCallConv(LLVMValueRef Instr, unsigned CC) {
-  Value *V = unwrap(Instr);
-  if (CallInst *CI = dyn_cast<CallInst>(V))
-    return CI->setCallingConv(static_cast<CallingConv::ID>(CC));
-  else if (InvokeInst *II = dyn_cast<InvokeInst>(V))
-    return II->setCallingConv(static_cast<CallingConv::ID>(CC));
-  llvm_unreachable("LLVMSetInstructionCallConv applies only to call and invoke!");
+  return CallSite(unwrap<Instruction>(Instr))
+    .setCallingConv(static_cast<CallingConv::ID>(CC));
 }
 
 void LLVMAddInstrAttribute(LLVMValueRef Instr, unsigned index,
@@ -2090,6 +2085,10 @@ void LLVMSetInstrParamAlignment(LLVMValueRef Instr, unsigned index,
                                                         index, B)));
 }
 
+LLVMValueRef LLVMGetCalledValue(LLVMValueRef Instr) {
+  return wrap(CallSite(unwrap<Instruction>(Instr)).getCalledValue());
+}
+
 /*--.. Operations on call instructions (only) ..............................--*/
 
 LLVMBool LLVMIsTailCall(LLVMValueRef Call) {

llvm/tools/llvm-c-test/echo.cpp

@@ -336,10 +336,10 @@ struct FunCloner {
       }
       case LLVMCall: {
         SmallVector<LLVMValueRef, 8> Args;
-        int ArgCount = LLVMGetNumOperands(Src) - 1;
+        int ArgCount = LLVMGetNumArgOperands(Src);
         for (int i = 0; i < ArgCount; i++)
           Args.push_back(CloneValue(LLVMGetOperand(Src, i)));
-        LLVMValueRef Fn = CloneValue(LLVMGetOperand(Src, ArgCount));
+        LLVMValueRef Fn = CloneValue(LLVMGetCalledValue(Src));
         Dst = LLVMBuildCall(Builder, Fn, Args.data(), ArgCount, Name);
         break;
       }