mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-12-23 12:08:25 +00:00
128 lines
4.0 KiB
C
128 lines
4.0 KiB
C
/*===- SystemUtils.h - Utilities to do low-level system stuff -------------===*\
|
|
*
|
|
* 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 file contains functions used to do a variety of low-level, often
|
|
* system-specific, tasks.
|
|
*
|
|
\*===----------------------------------------------------------------------===*/
|
|
|
|
#include "SysUtils.h"
|
|
#include "Config/dlfcn.h"
|
|
#include "Config/fcntl.h"
|
|
#include "Config/unistd.h"
|
|
#include "Config/sys/stat.h"
|
|
#include "Config/sys/types.h"
|
|
#include "Config/sys/wait.h"
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
/*
|
|
* isExecutable - This function returns true if given struct stat describes the
|
|
* file as being executable.
|
|
*/
|
|
unsigned isExecutable(const struct stat *buf) {
|
|
if (!(buf->st_mode & S_IFREG))
|
|
return 0; // Not a regular file?
|
|
|
|
if (buf->st_uid == getuid()) // Owner of file?
|
|
return buf->st_mode & S_IXUSR;
|
|
else if (buf->st_gid == getgid()) // In group of file?
|
|
return buf->st_mode & S_IXGRP;
|
|
else // Unrelated to file?
|
|
return buf->st_mode & S_IXOTH;
|
|
}
|
|
|
|
/*
|
|
* isExecutableFile - This function returns true if the filename specified
|
|
* exists and is executable.
|
|
*/
|
|
unsigned isExecutableFile(const char *ExeFileName) {
|
|
struct stat buf;
|
|
if (stat(ExeFileName, &buf))
|
|
return 0; // Must not be executable!
|
|
|
|
return isExecutable(&buf);
|
|
}
|
|
|
|
|
|
/*
|
|
* FindExecutable - Find a named executable in the directories listed in $PATH.
|
|
* If the executable cannot be found, returns NULL.
|
|
*/
|
|
char *FindExecutable(const char *ExeName) {
|
|
/* Try to find the executable in the path */
|
|
const char *PathStr = getenv("PATH");
|
|
if (PathStr == 0) return 0;
|
|
|
|
/* Now we have a colon separated list of directories to search, try them. */
|
|
unsigned PathLen = strlen(PathStr);
|
|
while (PathLen) {
|
|
/* Find the next colon */
|
|
const char *Colon = strchr(PathStr, ':');
|
|
|
|
/* Check to see if this first directory contains the executable... */
|
|
unsigned DirLen = Colon ? (unsigned)(Colon-PathStr) : strlen(PathStr);
|
|
char *FilePath = alloca(sizeof(char) * (DirLen+1+strlen(ExeName)+1));
|
|
unsigned i, e;
|
|
for (i = 0; i != DirLen; ++i)
|
|
FilePath[i] = PathStr[i];
|
|
FilePath[i] = '/';
|
|
for (i = 0, e = strlen(ExeName); i != e; ++i)
|
|
FilePath[DirLen + 1 + i] = ExeName[i];
|
|
FilePath[DirLen + 1 + i] = '\0';
|
|
if (isExecutableFile(FilePath))
|
|
return strdup(FilePath); /* Found the executable! */
|
|
|
|
/* If Colon is NULL, there are no more colon separators and no more dirs */
|
|
if (!Colon) break;
|
|
|
|
/* Nope, it wasn't in this directory, check the next range! */
|
|
PathLen -= DirLen;
|
|
PathStr = Colon;
|
|
while (*PathStr == ':') { /* Advance past colons */
|
|
PathStr++;
|
|
PathLen--;
|
|
}
|
|
|
|
/* Advance past the colon */
|
|
++Colon;
|
|
}
|
|
|
|
/* If we fell out, we ran out of directories to search, return failure. */
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* The type of the execve() function is long and boring, but required.
|
|
*/
|
|
typedef int(*execveTy)(const char*, char *const[], char *const[]);
|
|
|
|
/*
|
|
* This method finds the real `execve' call in the C library and executes the
|
|
* given program.
|
|
*/
|
|
int executeProgram(const char *filename, char *const argv[], char *const envp[])
|
|
{
|
|
/*
|
|
* Find a pointer to the *real* execve() function starting the search in the
|
|
* next library and forward, to avoid finding the one defined in this file.
|
|
*/
|
|
char *error;
|
|
execveTy execvePtr = (execveTy) dlsym(RTLD_NEXT, "execve");
|
|
if ((error = dlerror()) != NULL) {
|
|
fprintf(stderr, "%s\n", error);
|
|
return -1;
|
|
}
|
|
|
|
/* Really execute the program */
|
|
return execvePtr(filename, argv, envp);
|
|
}
|