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#include <iostream>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include "exec.hh"
#include "util.hh"
#include "globals.hh"
class AutoDelete
{
string path;
bool del;
public:
AutoDelete(const string & p) : path(p)
{
del = true;
}
~AutoDelete()
{
if (del) deletePath(path);
}
void cancel()
{
del = false;
}
};
static string pathNullDevice = "/dev/null";
/* Run a program. */
void runProgram(const string & program,
const Strings & args, const Environment & env)
{
/* Create a log file. */
string logFileName = nixLogDir + "/run.log";
string logCommand =
verbosity >= lvlDebug
? "tee -a " + logFileName + " >&2"
: "cat >> " + logFileName;
/* !!! auto-pclose on exit */
FILE * logFile = popen(logCommand.c_str(), "w"); /* !!! escaping */
if (!logFile)
throw SysError(format("creating log file `%1%'") % logFileName);
/* Create a temporary directory where the build will take
place. */
static int counter = 0;
string tmpDir = (format("/tmp/nix-%1%-%2%") % getpid() % counter++).str();
if (mkdir(tmpDir.c_str(), 0777) == -1)
throw SysError(format("creating directory `%1%'") % tmpDir);
AutoDelete delTmpDir(tmpDir);
/* Fork a child to build the package. */
pid_t pid;
switch (pid = fork()) {
case -1:
throw SysError("unable to fork");
case 0:
try { /* child */
if (chdir(tmpDir.c_str()) == -1)
throw SysError(format("changing into to `%1%'") % tmpDir);
/* Fill in the arguments. */
const char * argArr[args.size() + 2];
const char * * p = argArr;
string progName = baseNameOf(program);
*p++ = progName.c_str();
for (Strings::const_iterator i = args.begin();
i != args.end(); i++)
*p++ = i->c_str();
*p = 0;
/* Fill in the environment. */
Strings envStrs;
const char * envArr[env.size() + 1];
p = envArr;
for (Environment::const_iterator i = env.begin();
i != env.end(); i++)
*p++ = envStrs.insert(envStrs.end(),
i->first + "=" + i->second)->c_str();
*p = 0;
/* Dup the log handle into stderr. */
if (dup2(fileno(logFile), STDERR_FILENO) == -1)
throw SysError("cannot pipe standard error into log file");
/* Dup stderr to stdin. */
if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
throw SysError("cannot dup stderr into stdout");
/* Reroute stdin to /dev/null. */
int fdDevNull = open(pathNullDevice.c_str(), O_RDWR);
if (fdDevNull == -1)
throw SysError(format("cannot open `%1%'") % pathNullDevice);
if (dup2(fdDevNull, STDIN_FILENO) == -1)
throw SysError("cannot dup null device into stdin");
/* Execute the program. This should not return. */
execve(program.c_str(), (char * *) argArr, (char * *) envArr);
throw SysError(format("unable to execute %1%") % program);
} catch (exception & e) {
cerr << format("build error: %1%\n") % e.what();
}
_exit(1);
}
/* parent */
/* Close the logging pipe. Note that this should not cause
the logger to exit until builder exits (because the latter
has an open file handle to the former). */
pclose(logFile);
/* Wait for the child to finish. */
int status;
if (waitpid(pid, &status, 0) != pid)
throw Error("unable to wait for child");
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
if (keepFailed) {
msg(lvlTalkative,
format("build failed; keeping build directory `%1%'") % tmpDir);
delTmpDir.cancel();
}
throw Error("unable to build package");
}
}
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