fish-shell/src/builtin_disown.cpp
Mahmoud Al-Qudsi 394623bf08 Prevent disown from directly removing jobs
This prevents the `disown` builtin from directly removing jobs out of
the jobs list to prevent sanity issues, as `disown` may be called within
the context of a subjob (e.g. in a function or block) in which case the
parent job might not yet be done with the reference to the child job.

Instead, a flag is set and the parser removes the job from the list only
after the entire execution chain has completed.

Closes #5720.
2019-04-09 23:29:58 -05:00

110 lines
3.8 KiB
C++

// Implementation of the disown builtin.
#include "config.h" // IWYU pragma: keep
#include <errno.h>
#include <signal.h>
#include <set>
#include "builtin.h"
#include "builtin_disown.h"
#include "common.h"
#include "fallback.h" // IWYU pragma: keep
#include "io.h"
#include "parser.h"
#include "proc.h"
#include "wutil.h" // IWYU pragma: keep
/// Helper for builtin_disown.
static int disown_job(const wchar_t *cmd, parser_t &parser, io_streams_t &streams, job_t *j) {
if (j == nullptr) {
streams.err.append_format(_(L"%ls: Unknown job '%ls'\n"), L"bg");
builtin_print_error_trailer(parser, streams.err, cmd);
return STATUS_INVALID_ARGS;
}
// Stopped disowned jobs must be manually signaled; explain how to do so.
if (j->is_stopped()) {
killpg(j->pgid, SIGCONT);
const wchar_t *fmt =
_(L"%ls: job %d ('%ls') was stopped and has been signalled to continue.\n");
streams.err.append_format(fmt, cmd, j->job_id, j->command_wcstr());
}
// We cannot directly remove the job from the jobs() list as `disown` might be called
// within the context of a subjob which will cause the parent job to crash in exec_job().
// Instead, we set a flag and the parser removes the job from the jobs list later.
j->set_flag(job_flag_t::PENDING_REMOVAL, true);
add_disowned_pgid(j->pgid);
return STATUS_CMD_OK;
}
/// Builtin for removing jobs from the job list.
int builtin_disown(parser_t &parser, io_streams_t &streams, wchar_t **argv) {
const wchar_t *cmd = argv[0];
int argc = builtin_count_args(argv);
help_only_cmd_opts_t opts;
int optind;
int retval = parse_help_only_cmd_opts(opts, &optind, argc, argv, parser, streams);
if (retval != STATUS_CMD_OK) return retval;
if (opts.print_help) {
builtin_print_help(parser, streams, cmd, streams.out);
return STATUS_CMD_OK;
}
if (argv[1] == 0) {
// Select last constructed job (ie first job in the job queue) that is possible to disown.
// Stopped jobs can be disowned (they will be continued).
// Foreground jobs can be disowned.
// Even jobs that aren't under job control can be disowned!
job_t *job = nullptr;
for (const auto &j : jobs()) {
if (j->is_constructed() && (!j->is_completed())) {
job = j.get();
break;
}
}
if (job) {
retval = disown_job(cmd, parser, streams, job);
} else {
streams.err.append_format(_(L"%ls: There are no suitable jobs\n"), cmd);
retval = STATUS_CMD_ERROR;
}
} else {
std::set<job_t *> jobs;
// If one argument is not a valid pid (i.e. integer >= 0), fail without disowning anything,
// but still print errors for all of them.
// Non-existent jobs aren't an error, but information about them is useful.
// Multiple PIDs may refer to the same job; include the job only once by using a set.
for (int i = 1; argv[i]; i++) {
int pid = fish_wcstoi(argv[i]);
if (errno || pid < 0) {
streams.err.append_format(_(L"%ls: '%ls' is not a valid job specifier\n"), cmd,
argv[i]);
retval = STATUS_INVALID_ARGS;
} else {
if (job_t *j = parser.job_get_from_pid(pid)) {
jobs.insert(j);
} else {
streams.err.append_format(_(L"%ls: Could not find job '%d'\n"), cmd, pid);
}
}
}
if (retval != STATUS_CMD_OK) {
return retval;
}
// Disown all target jobs
for (const auto &j : jobs) {
retval |= disown_job(cmd, parser, streams, j);
}
}
return retval;
}