1 /*===- llvm-stub.c - Stub executable to run llvm bytecode files -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This tool is used by the gccld program to enable transparent execution of
11 // bytecode files by the user. Specifically, gccld outputs two files when asked
12 // to compile a <program> file:
13 // 1. It outputs the LLVM bytecode file to <program>.bc
14 // 2. It outputs a stub executable that runs lli on <program>.bc
16 // This allows the end user to just say ./<program> and have the JIT executed
17 // automatically. On unix, the stub executable emitted is actually a bourne
18 // shell script that does the forwarding. Windows does not like #!/bin/sh
19 // programs in .exe files, so we make it an actual program, defined here.
21 //===----------------------------------------------------------------------===*/
26 #include "llvm/Config/unistd.h" /* provides definition of execve */
28 int main(int argc, char** argv) {
29 const char *Interp = getenv("LLVMINTERP");
31 if (Interp == 0) Interp = "lli";
33 /* Set up the command line options to pass to the JIT. */
34 Args = (const char**)malloc(sizeof(char*) * (argc+2));
35 /* argv[0] is the JIT */
39 /* Cygwin strips the .exe suffix off of argv[0] to "help" us. Put it back
42 argv[0] = strcat(strcpy((char*)malloc(strlen(argv[0])+5), argv[0]), ".exe");
45 /* argv[1] is argv[0] + ".bc". */
46 Args[1] = strcat(strcpy((char*)malloc(strlen(argv[0])+4), argv[0]), ".bc");
48 /* The rest of the args are as before. */
49 memcpy(Args+2, argv+1, sizeof(char*)*argc);
52 execvp(Interp, (char *const*)Args);
54 /* if _execv returns, the JIT could not be started. */
55 fprintf(stderr, "Could not execute the LLVM JIT. Either add 'lli' to your"
56 " path, or set the\ninterpreter you want to use in the LLVMINTERP "
57 "environment variable.\n");