Simple integer sum function, JIT'ed with the LLVM C API

Makefile

CC=clang
CXX=clang++

all: sum

sum.o: sum.c
	$(CC) -g `llvm-config --cflags` -c $<

sum: sum.o
	$(CXX) `llvm-config --cxxflags --ldflags --libs core executionengine jit interpreter analysis native --system-libs` $< -o $@

clean:
	-rm -f sum.o sum

sum.c

/**
 * LLVM equivalent of:
 *
 * int sum(int a, int b) {
 *     return a + b;
 * }
 */

#include <llvm-c/Core.h>
#include <llvm-c/ExecutionEngine.h>
#include <llvm-c/Target.h>
#include <llvm-c/Analysis.h>

#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char const *argv[]) {
    LLVMLinkInJIT();
    LLVMInitializeNativeTarget();

    LLVMModuleRef mod = LLVMModuleCreateWithName("my_module");

    LLVMTypeRef param_types[] = { LLVMInt32Type(), LLVMInt32Type() };
    LLVMTypeRef ret_type = LLVMFunctionType(LLVMInt32Type(), param_types, 2, 0);
    LLVMValueRef sum = LLVMAddFunction(mod, "sum", ret_type);

    LLVMBasicBlockRef entry = LLVMAppendBasicBlock(sum, "entry");

    LLVMBuilderRef builder = LLVMCreateBuilder();
    LLVMPositionBuilderAtEnd(builder, entry);
    LLVMValueRef tmp = LLVMBuildAdd(builder, LLVMGetParam(sum, 0), LLVMGetParam(sum, 1), "tmp");
    LLVMBuildRet(builder, tmp);

    char *error = NULL;
    LLVMVerifyModule(mod, LLVMAbortProcessAction, &error);
    LLVMDisposeMessage(error);

    LLVMExecutionEngineRef engine;
    error = NULL;
    if (LLVMCreateExecutionEngineForModule(&engine, mod, &error) != 0) {
        fprintf(stderr, "create ee failed\n");
        abort();
    }
    if (error) {
        fprintf(stderr, "err: %s\n", error);
        LLVMDisposeMessage(error);
        exit(EXIT_FAILURE);
    }

    if (argc < 3) {
        fprintf(stderr, "usage: %s x y\n", argv[0]);
        exit(EXIT_FAILURE);
    }
    long long x = strtoll(argv[1], NULL, 10);
    long long y = strtoll(argv[2], NULL, 10);

    LLVMGenericValueRef args[] = {
        LLVMCreateGenericValueOfInt(LLVMInt32Type(), x, 0),
        LLVMCreateGenericValueOfInt(LLVMInt32Type(), y, 0)
    };
    LLVMGenericValueRef res = LLVMRunFunction(engine, sum, 2, args);
    printf("%d\n", (int)LLVMGenericValueToInt(res, 0));

    LLVMDisposeBuilder(builder);
    LLVMDisposeExecutionEngine(engine);
}