1 /** This code is public domain, and taken from
2 * https://github.com/paulsmith/getting-started-llvm-c-api/blob/master/sum.c
3 */
4 /**
5 * LLVM equivalent of:
6 *
7 * int sum(int a, int b) {
8 * return a + b;
9 * }
10 */
11
12 #include <llvm-c/Core.h>
13 #include <llvm-c/ExecutionEngine.h>
14 #include <llvm-c/Target.h>
15 #include <llvm-c/Analysis.h>
16 #include <llvm-c/BitWriter.h>
17
18 #include <inttypes.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21
main(int argc,char const * argv[])22 int main(int argc, char const *argv[]) {
23 LLVMModuleRef mod = LLVMModuleCreateWithName("my_module");
24
25 LLVMTypeRef param_types[] = { LLVMInt32Type(), LLVMInt32Type() };
26 LLVMTypeRef ret_type = LLVMFunctionType(LLVMInt32Type(), param_types, 2, 0);
27 LLVMValueRef sum = LLVMAddFunction(mod, "sum", ret_type);
28
29 LLVMBasicBlockRef entry = LLVMAppendBasicBlock(sum, "entry");
30
31 LLVMBuilderRef builder = LLVMCreateBuilder();
32 LLVMPositionBuilderAtEnd(builder, entry);
33 LLVMValueRef tmp = LLVMBuildAdd(builder, LLVMGetParam(sum, 0), LLVMGetParam(sum, 1), "tmp");
34 LLVMBuildRet(builder, tmp);
35
36 char *error = NULL;
37 LLVMVerifyModule(mod, LLVMAbortProcessAction, &error);
38 LLVMDisposeMessage(error);
39
40 LLVMExecutionEngineRef engine;
41 error = NULL;
42 LLVMLinkInMCJIT();
43 LLVMInitializeNativeAsmPrinter();
44 LLVMInitializeNativeTarget();
45 if (LLVMCreateExecutionEngineForModule(&engine, mod, &error) != 0) {
46 fprintf(stderr, "failed to create execution engine\n");
47 abort();
48 }
49 if (error) {
50 fprintf(stderr, "error: %s\n", error);
51 LLVMDisposeMessage(error);
52 exit(EXIT_FAILURE);
53 }
54
55 if (argc < 3) {
56 fprintf(stderr, "usage: %s x y\n", argv[0]);
57 exit(EXIT_FAILURE);
58 }
59 long long x = strtoll(argv[1], NULL, 10);
60 long long y = strtoll(argv[2], NULL, 10);
61
62 LLVMGenericValueRef args[] = {
63 LLVMCreateGenericValueOfInt(LLVMInt32Type(), x, 0),
64 LLVMCreateGenericValueOfInt(LLVMInt32Type(), y, 0)
65 };
66 LLVMGenericValueRef res = LLVMRunFunction(engine, sum, 2, args);
67 printf("%d\n", (int)LLVMGenericValueToInt(res, 0));
68
69 // Write out bitcode to file
70 if (LLVMWriteBitcodeToFile(mod, "sum.bc") != 0) {
71 fprintf(stderr, "error writing bitcode to file, skipping\n");
72 }
73
74 LLVMDisposeBuilder(builder);
75 LLVMDisposeExecutionEngine(engine);
76 }
77