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#include <map>
#include <iostream>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include "eval.hh"
#include "globals.hh"
#include "values.hh"
#include "db.hh"
/* A Unix environment is a mapping from strings to strings. */
typedef map<string, string> Environment;
/* Return true iff the given path exists. */
bool pathExists(const string & path)
{
int res;
struct stat st;
res = stat(path.c_str(), &st);
if (!res) return true;
if (errno != ENOENT)
throw SysError(format("getting status of %1%") % path);
return false;
}
/* Run a program. */
static void runProgram(const string & program, Environment env)
{
/* Create a log file. */
string logFileName = nixLogDir + "/run.log";
/* !!! auto-pclose on exit */
FILE * logFile = popen(("tee " + logFileName + " >&2").c_str(), "w"); /* !!! escaping */
if (!logFile)
throw SysError(format("unable to create log file %1%") % logFileName);
/* 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 0
/* Try to use a prebuilt. */
string prebuiltHashS, prebuiltFile;
if (queryDB(nixDB, dbPrebuilts, hash, prebuiltHashS)) {
try {
prebuiltFile = getFile(parseHash(prebuiltHashS));
} catch (Error e) {
cerr << "cannot obtain prebuilt (ignoring): " << e.what() << endl;
goto build;
}
cerr << "substituting prebuilt " << prebuiltFile << endl;
int res = system(("tar xfj " + prebuiltFile + " 1>&2").c_str()); // !!! escaping
if (WEXITSTATUS(res) != 0)
/* This is a fatal error, because path may now
have clobbered. */
throw Error("cannot unpack " + prebuiltFile);
_exit(0);
}
#endif
// build:
/* Fill in the environment. We don't bother freeing
the strings, since we'll exec or die soon
anyway. */
const char * env2[env.size() + 1];
int i = 0;
for (Environment::iterator it = env.begin();
it != env.end(); it++, i++)
env2[i] = (new string(it->first + "=" + it->second))->c_str();
env2[i] = 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");
/* Make the program executable. !!! hack. */
if (chmod(program.c_str(), 0755))
throw SysError("cannot make program executable");
/* Execute the program. This should not return. */
execle(program.c_str(), baseNameOf(program).c_str(), 0, env2);
throw SysError(format("unable to execute %1%") % program);
} catch (exception & e) {
cerr << format("build error: %1%\n") % e.what();
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