1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
//===- llvm/System/Unix/Program.cpp -----------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and 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"
#include <iostream>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SIGNAL_H
#include <signal.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
namespace llvm {
using namespace sys;
// 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();
// FIXME: have to check for absolute filename - we cannot assume anything
// about "." being in $PATH
if (temp.canExecute()) // already executable as is
return temp;
// At this point, the file name is valid and its not executable
// 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.
unsigned 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 RedirectFD(const std::string &File, int FD, std::string* ErrMsg) {
if (File.empty()) return false; // Noop
// 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") + "!\n");
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 bool Timeout = false;
static void TimeOutHandler(int Sig) {
Timeout = true;
}
int
Program::ExecuteAndWait(const Path& path,
const char** args,
const char** envp,
const Path** redirects,
unsigned secondsToWait,
std::string* ErrMsg)
{
if (!path.canExecute()) {
if (ErrMsg)
*ErrMsg = path.toString() + " is not executable";
return -1;
}
#ifdef HAVE_SYS_WAIT_H
// Create a child process.
int child = fork();
switch (child) {
// An error occured: Return to the caller.
case -1:
MakeErrMsg(ErrMsg, "Couldn't fork");
return -1;
// Child process: Execute the program.
case 0: {
// Redirect file descriptors...
if (redirects) {
if (redirects[0]) {
if (redirects[0]->isEmpty()) {
if (RedirectFD("/dev/null",0,ErrMsg)) { return -1; }
} else {
if (RedirectFD(redirects[0]->toString(), 0,ErrMsg)) { return -1; }
}
}
if (redirects[1]) {
if (redirects[1]->isEmpty()) {
if (RedirectFD("/dev/null",1,ErrMsg)) { return -1; }
} else {
if (RedirectFD(redirects[1]->toString(),1,ErrMsg)) { return -1; }
}
}
if (redirects[1] && redirects[2] &&
*(redirects[1]) != *(redirects[2])) {
if (redirects[2]->isEmpty()) {
if (RedirectFD("/dev/null",2,ErrMsg)) { return -1; }
} else {
if (RedirectFD(redirects[2]->toString(), 2,ErrMsg)) { return -1; }
}
} else if (-1 == dup2(1,2)) {
MakeErrMsg(ErrMsg, "Can't redirect");
return -1;
}
}
// Execute!
if (envp != 0)
execve (path.c_str(), (char** const)args, (char**)envp);
else
execv (path.c_str(), (char** const)args);
// If the execve() failed, we should exit and let the parent pick up
// our non-zero exit status.
exit (errno);
}
// Parent process: Break out of the switch to do our processing.
default:
break;
}
// Make sure stderr and stdout have been flushed
std::cerr << std::flush;
std::cout << std::flush;
fsync(1);
fsync(2);
struct sigaction Act, Old;
// Install a timeout handler.
if (secondsToWait) {
Timeout = false;
Act.sa_sigaction = 0;
Act.sa_handler = TimeOutHandler;
sigemptyset(&Act.sa_mask);
Act.sa_flags = 0;
sigaction(SIGALRM, &Act, &Old);
alarm(secondsToWait);
}
// Parent process: Wait for the child process to terminate.
int status;
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");
return -1; // Timeout detected
} else {
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::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;
}
}
|