[llvm-dev] mcjit C interface problems

[Toshiyasu Morita via llvm-dev]

Hi, I'm attempting to use MCJIT with the C interface with llvm-3.9.0, and
it doesn't seem to work. This code is derived from Paul Smith's example
code:

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

  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;
  LLVMLinkInMCJIT();
  LLVMInitializeNativeTarget();
  LLVMInitializeNativeAsmPrinter();
  LLVMInitializeNativeAsmParser();

  if (LLVMCreateExecutionEngineForModule(&engine, mod, &error) != 0) {
    fprintf(stderr, "failed to create execution engine\n");
    abort();
  }
  if (error) {
    fprintf(stderr, "error: %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)};

  printf("args[0]: %d\n", (int)LLVMGenericValueToInt(args[0], 0));
  printf("args[1]: %d\n", (int)LLVMGenericValueToInt(args[1], 0));

  LLVMGenericValueRef res = LLVMRunFunction(engine, sum, 2, args);

  printf("result: %d\n", (int)LLVMGenericValueToInt(res, 0));

  LLVMDumpModule(mod);

  // Write out bitcode to file
  if (LLVMWriteBitcodeToFile(mod, "sum.bc") != 0) { fprintf(stderr, "error
writing bitcode to file, skipping\n"); }

  LLVMDisposeBuilder(builder);
  LLVMDisposeExecutionEngine(engine);
}

Here's what I see when I run it:
$ ./capi_test 5 6
args[0]: 5
args[1]: 6
result: 5
; ModuleID = 'my_module'
source_filename = "my_module"
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"

define i32 @sum(i32, i32) {
entry:
  %tmp = add i32 %0, %1
  ret i32 %tmp
}

It seems to fail to add, and always returns the first argument.
Any help greatly appreciated.

Toshi
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