llvm-project/llvm/tools/llvm-stub/llvm-stub.c

60 lines
2.2 KiB
C

/*===- llvm-stub.c - Stub executable to run llvm bytecode files -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This tool is used by the gccld program to enable transparent execution of
// bytecode files by the user. Specifically, gccld outputs two files when asked
// to compile a <program> file:
// 1. It outputs the LLVM bytecode file to <program>.bc
// 2. It outputs a stub executable that runs lli on <program>.bc
//
// This allows the end user to just say ./<program> and have the JIT executed
// automatically. On unix, the stub executable emitted is actually a bourne
// shell script that does the forwarding. Windows does not like #!/bin/sh
// programs in .exe files, so we make it an actual program, defined here.
//
//===----------------------------------------------------------------------===*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "llvm/Config/unistd.h" /* provides definition of execve */
int main(int argc, char** argv) {
const char *Interp = getenv("LLVMINTERP");
const char **Args;
if (Interp == 0) Interp = "lli";
/* Set up the command line options to pass to the JIT. */
Args = (const char**)malloc(sizeof(char*) * (argc+2));
/* argv[0] is the JIT */
Args[0] = Interp;
#ifdef __CYGWIN32__
/* Cygwin strips the .exe suffix off of argv[0] to "help" us. Put it back
* on.
*/
argv[0] = strcat(strcpy((char*)malloc(strlen(argv[0])+5), argv[0]), ".exe");
#endif
/* argv[1] is argv[0] + ".bc". */
Args[1] = strcat(strcpy((char*)malloc(strlen(argv[0])+4), argv[0]), ".bc");
/* The rest of the args are as before. */
memcpy(Args+2, argv+1, sizeof(char*)*argc);
/* Run the JIT. */
execvp(Interp, (char *const*)Args);
/* if _execv returns, the JIT could not be started. */
fprintf(stderr, "Could not execute the LLVM JIT. Either add 'lli' to your"
" path, or set the\ninterpreter you want to use in the LLVMINTERP "
"environment variable.\n");
return 1;
}