llvm-6502/lib/System/Unix/Program.inc

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//===- llvm/System/Unix/Program.cpp -----------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Unix specific portion of the Program class.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only generic UNIX code that
//=== is guaranteed to work on *all* UNIX variants.
//===----------------------------------------------------------------------===//
#include <llvm/Config/config.h>
#include "Unix.h"
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
#if HAVE_SIGNAL_H
#include <signal.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
namespace llvm {
using namespace sys;
Program::Program() : Data_(0) {}
Program::~Program() {}
unsigned Program::GetPid() const {
uint64_t pid = reinterpret_cast<uint64_t>(Data_);
return static_cast<unsigned>(pid);
}
// This function just uses the PATH environment variable to find the program.
Path
Program::FindProgramByName(const std::string& progName) {
// Check some degenerate cases
if (progName.length() == 0) // no program
return Path();
Path temp;
if (!temp.set(progName)) // invalid name
return Path();
// Use the given path verbatim if it contains any slashes; this matches
// the behavior of sh(1) and friends.
if (progName.find('/') != std::string::npos)
return temp;
// At this point, the file name does not contain slashes. Search for it
// through the directories specified in the PATH environment variable.
// Get the path. If its empty, we can't do anything to find it.
const char *PathStr = getenv("PATH");
if (PathStr == 0)
return Path();
// Now we have a colon separated list of directories to search; try them.
size_t PathLen = strlen(PathStr);
while (PathLen) {
// Find the first colon...
const char *Colon = std::find(PathStr, PathStr+PathLen, ':');
// Check to see if this first directory contains the executable...
Path FilePath;
if (FilePath.set(std::string(PathStr,Colon))) {
FilePath.appendComponent(progName);
if (FilePath.canExecute())
return FilePath; // Found the executable!
}
// Nope it wasn't in this directory, check the next path in the list!
PathLen -= Colon-PathStr;
PathStr = Colon;
// Advance past duplicate colons
while (*PathStr == ':') {
PathStr++;
PathLen--;
}
}
return Path();
}
static bool RedirectIO(const Path *Path, int FD, std::string* ErrMsg) {
if (Path == 0)
// Noop
return false;
std::string File;
if (Path->isEmpty())
// Redirect empty paths to /dev/null
File = "/dev/null";
else
File = Path->str();
// Open the file
int InFD = open(File.c_str(), FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666);
if (InFD == -1) {
MakeErrMsg(ErrMsg, "Cannot open file '" + File + "' for "
+ (FD == 0 ? "input" : "output"));
return true;
}
// Install it as the requested FD
if (-1 == dup2(InFD, FD)) {
MakeErrMsg(ErrMsg, "Cannot dup2");
return true;
}
close(InFD); // Close the original FD
return false;
}
static void SetMemoryLimits (unsigned size)
{
#if HAVE_SYS_RESOURCE_H
struct rlimit r;
__typeof__ (r.rlim_cur) limit = (__typeof__ (r.rlim_cur)) (size) * 1048576;
// Heap size
getrlimit (RLIMIT_DATA, &r);
r.rlim_cur = limit;
setrlimit (RLIMIT_DATA, &r);
#ifdef RLIMIT_RSS
// Resident set size.
getrlimit (RLIMIT_RSS, &r);
r.rlim_cur = limit;
setrlimit (RLIMIT_RSS, &r);
#endif
#ifdef RLIMIT_AS // e.g. NetBSD doesn't have it.
// Virtual memory.
getrlimit (RLIMIT_AS, &r);
r.rlim_cur = limit;
setrlimit (RLIMIT_AS, &r);
#endif
#endif
}
bool
Program::Execute(const Path& path,
const char** args,
const char** envp,
const Path** redirects,
unsigned memoryLimit,
std::string* ErrMsg)
{
if (!path.canExecute()) {
if (ErrMsg)
*ErrMsg = path.str() + " is not executable";
return false;
}
// Create a child process.
int child = fork();
switch (child) {
// An error occured: Return to the caller.
case -1:
MakeErrMsg(ErrMsg, "Couldn't fork");
return false;
// Child process: Execute the program.
case 0: {
// Redirect file descriptors...
if (redirects) {
// Redirect stdin
if (RedirectIO(redirects[0], 0, ErrMsg)) { return false; }
// Redirect stdout
if (RedirectIO(redirects[1], 1, ErrMsg)) { return false; }
if (redirects[1] && redirects[2] &&
*(redirects[1]) == *(redirects[2])) {
// If stdout and stderr should go to the same place, redirect stderr
// to the FD already open for stdout.
if (-1 == dup2(1,2)) {
MakeErrMsg(ErrMsg, "Can't redirect stderr to stdout");
return false;
}
} else {
// Just redirect stderr
if (RedirectIO(redirects[2], 2, ErrMsg)) { return false; }
}
}
// Set memory limits
if (memoryLimit!=0) {
SetMemoryLimits(memoryLimit);
}
// Execute!
if (envp != 0)
execve(path.c_str(), (char**)args, (char**)envp);
else
execv(path.c_str(), (char**)args);
// If the execve() failed, we should exit. Follow Unix protocol and
// return 127 if the executable was not found, and 126 otherwise.
// Use _exit rather than exit so that atexit functions and static
// object destructors cloned from the parent process aren't
// redundantly run, and so that any data buffered in stdio buffers
// cloned from the parent aren't redundantly written out.
_exit(errno == ENOENT ? 127 : 126);
}
// Parent process: Break out of the switch to do our processing.
default:
break;
}
Data_ = reinterpret_cast<void*>(child);
return true;
}
int
Program::Wait(unsigned secondsToWait,
std::string* ErrMsg)
{
#ifdef HAVE_SYS_WAIT_H
struct sigaction Act, Old;
if (Data_ == 0) {
MakeErrMsg(ErrMsg, "Process not started!");
return -1;
}
// Install a timeout handler.
if (secondsToWait) {
memset(&Act, 0, sizeof(Act));
Act.sa_handler = SIG_IGN;
sigemptyset(&Act.sa_mask);
sigaction(SIGALRM, &Act, &Old);
alarm(secondsToWait);
}
// Parent process: Wait for the child process to terminate.
int status;
uint64_t pid = reinterpret_cast<uint64_t>(Data_);
pid_t child = static_cast<pid_t>(pid);
while (wait(&status) != child)
if (secondsToWait && errno == EINTR) {
// Kill the child.
kill(child, SIGKILL);
// Turn off the alarm and restore the signal handler
alarm(0);
sigaction(SIGALRM, &Old, 0);
// Wait for child to die
if (wait(&status) != child)
MakeErrMsg(ErrMsg, "Child timed out but wouldn't die");
else
MakeErrMsg(ErrMsg, "Child timed out", 0);
return -1; // Timeout detected
} else if (errno != EINTR) {
MakeErrMsg(ErrMsg, "Error waiting for child process");
return -1;
}
// We exited normally without timeout, so turn off the timer.
if (secondsToWait) {
alarm(0);
sigaction(SIGALRM, &Old, 0);
}
// Return the proper exit status. 0=success, >0 is programs' exit status,
// <0 means a signal was returned, -9999999 means the program dumped core.
int result = 0;
if (WIFEXITED(status))
result = WEXITSTATUS(status);
else if (WIFSIGNALED(status))
result = 0 - WTERMSIG(status);
#ifdef WCOREDUMP
else if (WCOREDUMP(status))
result |= 0x01000000;
#endif
return result;
#else
return -99;
#endif
}
bool
Program::Kill(std::string* ErrMsg) {
if (Data_ == 0) {
MakeErrMsg(ErrMsg, "Process not started!");
return true;
}
uint64_t pid64 = reinterpret_cast<uint64_t>(Data_);
pid_t pid = static_cast<pid_t>(pid64);
if (kill(pid, SIGKILL) != 0) {
MakeErrMsg(ErrMsg, "The process couldn't be killed!");
return true;
}
return false;
}
bool Program::ChangeStdinToBinary(){
// Do nothing, as Unix doesn't differentiate between text and binary.
return false;
}
bool Program::ChangeStdoutToBinary(){
// Do nothing, as Unix doesn't differentiate between text and binary.
return false;
}
}