blob: 81248971b640b77a5bc2f713d22879e73335788a [file] [log] [blame]
/* Job execution and handling for GNU Make.
Copyright (C) 1988-2016 Free Software Foundation, Inc.
This file is part of GNU Make.
GNU Make is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3 of the License, or (at your option) any later
version.
GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>. */
#include "makeint.h"
#include <assert.h>
#include "job.h"
#include "debug.h"
#include "filedef.h"
#include "commands.h"
#include "variable.h"
#include "os.h"
#include <string.h>
/* Default shell to use. */
#ifdef WINDOWS32
#ifdef HAVE_STRINGS_H
#include <strings.h> /* for strcasecmp, strncasecmp */
#endif
#include <windows.h>
const char *default_shell = "sh.exe";
int no_default_sh_exe = 1;
int batch_mode_shell = 1;
HANDLE main_thread;
#elif defined (_AMIGA)
const char *default_shell = "";
extern int MyExecute (char **);
int batch_mode_shell = 0;
#elif defined (__MSDOS__)
/* The default shell is a pointer so we can change it if Makefile
says so. It is without an explicit path so we get a chance
to search the $PATH for it (since MSDOS doesn't have standard
directories we could trust). */
const char *default_shell = "command.com";
int batch_mode_shell = 0;
#elif defined (__EMX__)
const char *default_shell = "/bin/sh";
int batch_mode_shell = 0;
#elif defined (VMS)
# include <descrip.h>
# include <stsdef.h>
const char *default_shell = "";
int batch_mode_shell = 0;
#define strsignal vms_strsignal
char * vms_strsignal (int status);
#ifndef C_FACILITY_NO
# define C_FACILITY_NO 0x350000
#endif
#ifndef VMS_POSIX_EXIT_MASK
# define VMS_POSIX_EXIT_MASK (C_FACILITY_NO | 0xA000)
#endif
#else
const char *default_shell = "/bin/sh";
int batch_mode_shell = 0;
#endif
#ifdef __MSDOS__
# include <process.h>
static int execute_by_shell;
static int dos_pid = 123;
int dos_status;
int dos_command_running;
#endif /* __MSDOS__ */
#ifdef _AMIGA
# include <proto/dos.h>
static int amiga_pid = 123;
static int amiga_status;
static char amiga_bname[32];
static int amiga_batch_file;
#endif /* Amiga. */
#ifdef VMS
# ifndef __GNUC__
# include <processes.h>
# endif
# include <starlet.h>
# include <lib$routines.h>
static void vmsWaitForChildren (int *);
#endif
#ifdef WINDOWS32
# include <windows.h>
# include <io.h>
# include <process.h>
# include "sub_proc.h"
# include "w32err.h"
# include "pathstuff.h"
# define WAIT_NOHANG 1
#endif /* WINDOWS32 */
#ifdef __EMX__
# include <process.h>
#endif
#if defined (HAVE_SYS_WAIT_H) || defined (HAVE_UNION_WAIT)
# include <sys/wait.h>
#endif
#ifdef HAVE_WAITPID
# define WAIT_NOHANG(status) waitpid (-1, (status), WNOHANG)
#else /* Don't have waitpid. */
# ifdef HAVE_WAIT3
# ifndef wait3
extern int wait3 ();
# endif
# define WAIT_NOHANG(status) wait3 ((status), WNOHANG, (struct rusage *) 0)
# endif /* Have wait3. */
#endif /* Have waitpid. */
#if !defined (wait) && !defined (POSIX)
int wait ();
#endif
#ifndef HAVE_UNION_WAIT
# define WAIT_T int
# ifndef WTERMSIG
# define WTERMSIG(x) ((x) & 0x7f)
# endif
# ifndef WCOREDUMP
# define WCOREDUMP(x) ((x) & 0x80)
# endif
# ifndef WEXITSTATUS
# define WEXITSTATUS(x) (((x) >> 8) & 0xff)
# endif
# ifndef WIFSIGNALED
# define WIFSIGNALED(x) (WTERMSIG (x) != 0)
# endif
# ifndef WIFEXITED
# define WIFEXITED(x) (WTERMSIG (x) == 0)
# endif
#else /* Have 'union wait'. */
# define WAIT_T union wait
# ifndef WTERMSIG
# define WTERMSIG(x) ((x).w_termsig)
# endif
# ifndef WCOREDUMP
# define WCOREDUMP(x) ((x).w_coredump)
# endif
# ifndef WEXITSTATUS
# define WEXITSTATUS(x) ((x).w_retcode)
# endif
# ifndef WIFSIGNALED
# define WIFSIGNALED(x) (WTERMSIG(x) != 0)
# endif
# ifndef WIFEXITED
# define WIFEXITED(x) (WTERMSIG(x) == 0)
# endif
#endif /* Don't have 'union wait'. */
#if !defined(HAVE_UNISTD_H) && !defined(WINDOWS32)
int dup2 ();
int execve ();
void _exit ();
# ifndef VMS
int geteuid ();
int getegid ();
int setgid ();
int getgid ();
# endif
#endif
/* Different systems have different requirements for pid_t.
Plus we have to support gettext string translation... Argh. */
static const char *
pid2str (pid_t pid)
{
static char pidstring[100];
#if defined(WINDOWS32) && (__GNUC__ > 3 || _MSC_VER > 1300)
/* %Id is only needed for 64-builds, which were not supported by
older versions of Windows compilers. */
sprintf (pidstring, "%Id", pid);
#else
sprintf (pidstring, "%lu", (unsigned long) pid);
#endif
return pidstring;
}
#ifndef HAVE_GETLOADAVG
int getloadavg (double loadavg[], int nelem);
#endif
static void free_child (struct child *);
static void start_job_command (struct child *child);
static int load_too_high (void);
static int job_next_command (struct child *);
static int start_waiting_job (struct child *);
/* Chain of all live (or recently deceased) children. */
struct child *children = 0;
/* Number of children currently running. */
unsigned int job_slots_used = 0;
/* Nonzero if the 'good' standard input is in use. */
static int good_stdin_used = 0;
/* Chain of children waiting to run until the load average goes down. */
static struct child *waiting_jobs = 0;
/* Non-zero if we use a *real* shell (always so on Unix). */
int unixy_shell = 1;
/* Number of jobs started in the current second. */
unsigned long job_counter = 0;
/* Number of jobserver tokens this instance is currently using. */
unsigned int jobserver_tokens = 0;
#ifdef WINDOWS32
/*
* The macro which references this function is defined in makeint.h.
*/
int
w32_kill (pid_t pid, int sig)
{
return ((process_kill ((HANDLE)pid, sig) == TRUE) ? 0 : -1);
}
/* This function creates a temporary file name with an extension specified
* by the unixy arg.
* Return an xmalloc'ed string of a newly created temp file and its
* file descriptor, or die. */
static char *
create_batch_file (char const *base, int unixy, int *fd)
{
const char *const ext = unixy ? "sh" : "bat";
const char *error_string = NULL;
char temp_path[MAXPATHLEN]; /* need to know its length */
unsigned path_size = GetTempPath (sizeof temp_path, temp_path);
int path_is_dot = 0;
/* The following variable is static so we won't try to reuse a name
that was generated a little while ago, because that file might
not be on disk yet, since we use FILE_ATTRIBUTE_TEMPORARY below,
which tells the OS it doesn't need to flush the cache to disk.
If the file is not yet on disk, we might think the name is
available, while it really isn't. This happens in parallel
builds, where Make doesn't wait for one job to finish before it
launches the next one. */
static unsigned uniq = 0;
static int second_loop = 0;
const unsigned sizemax = strlen (base) + strlen (ext) + 10;
if (path_size == 0)
{
path_size = GetCurrentDirectory (sizeof temp_path, temp_path);
path_is_dot = 1;
}
++uniq;
if (uniq >= 0x10000 && !second_loop)
{
/* If we already had 64K batch files in this
process, make a second loop through the numbers,
looking for free slots, i.e. files that were
deleted in the meantime. */
second_loop = 1;
uniq = 1;
}
while (path_size > 0 &&
path_size + sizemax < sizeof temp_path &&
!(uniq >= 0x10000 && second_loop))
{
unsigned size = sprintf (temp_path + path_size,
"%s%s-%x.%s",
temp_path[path_size - 1] == '\\' ? "" : "\\",
base, uniq, ext);
HANDLE h = CreateFile (temp_path, /* file name */
GENERIC_READ | GENERIC_WRITE, /* desired access */
0, /* no share mode */
NULL, /* default security attributes */
CREATE_NEW, /* creation disposition */
FILE_ATTRIBUTE_NORMAL | /* flags and attributes */
FILE_ATTRIBUTE_TEMPORARY, /* we'll delete it */
NULL); /* no template file */
if (h == INVALID_HANDLE_VALUE)
{
const DWORD er = GetLastError ();
if (er == ERROR_FILE_EXISTS || er == ERROR_ALREADY_EXISTS)
{
++uniq;
if (uniq == 0x10000 && !second_loop)
{
second_loop = 1;
uniq = 1;
}
}
/* the temporary path is not guaranteed to exist */
else if (path_is_dot == 0)
{
path_size = GetCurrentDirectory (sizeof temp_path, temp_path);
path_is_dot = 1;
}
else
{
error_string = map_windows32_error_to_string (er);
break;
}
}
else
{
const unsigned final_size = path_size + size + 1;
char *const path = xmalloc (final_size);
memcpy (path, temp_path, final_size);
*fd = _open_osfhandle ((intptr_t)h, 0);
if (unixy)
{
char *p;
int ch;
for (p = path; (ch = *p) != 0; ++p)
if (ch == '\\')
*p = '/';
}
return path; /* good return */
}
}
*fd = -1;
if (error_string == NULL)
error_string = _("Cannot create a temporary file\n");
O (fatal, NILF, error_string);
/* not reached */
return NULL;
}
#endif /* WINDOWS32 */
#ifdef __EMX__
/* returns whether path is assumed to be a unix like shell. */
int
_is_unixy_shell (const char *path)
{
/* list of non unix shells */
const char *known_os2shells[] = {
"cmd.exe",
"cmd",
"4os2.exe",
"4os2",
"4dos.exe",
"4dos",
"command.com",
"command",
NULL
};
/* find the rightmost '/' or '\\' */
const char *name = strrchr (path, '/');
const char *p = strrchr (path, '\\');
unsigned i;
if (name && p) /* take the max */
name = (name > p) ? name : p;
else if (p) /* name must be 0 */
name = p;
else if (!name) /* name and p must be 0 */
name = path;
if (*name == '/' || *name == '\\') name++;
i = 0;
while (known_os2shells[i] != NULL)
{
if (strcasecmp (name, known_os2shells[i]) == 0)
return 0; /* not a unix shell */
i++;
}
/* in doubt assume a unix like shell */
return 1;
}
#endif /* __EMX__ */
/* determines whether path looks to be a Bourne-like shell. */
int
is_bourne_compatible_shell (const char *path)
{
/* List of known POSIX (or POSIX-ish) shells. */
static const char *unix_shells[] = {
"sh",
"bash",
"ksh",
"rksh",
"zsh",
"ash",
"dash",
NULL
};
const char **s;
/* find the rightmost '/' or '\\' */
const char *name = strrchr (path, '/');
char *p = strrchr (path, '\\');
if (name && p) /* take the max */
name = (name > p) ? name : p;
else if (p) /* name must be 0 */
name = p;
else if (!name) /* name and p must be 0 */
name = path;
if (*name == '/' || *name == '\\')
++name;
/* this should be able to deal with extensions on Windows-like systems */
for (s = unix_shells; *s != NULL; ++s)
{
#if defined(WINDOWS32) || defined(__MSDOS__)
unsigned int len = strlen (*s);
if ((strlen (name) >= len && STOP_SET (name[len], MAP_DOT|MAP_NUL))
&& strncasecmp (name, *s, len) == 0)
#else
if (strcmp (name, *s) == 0)
#endif
return 1; /* a known unix-style shell */
}
/* if not on the list, assume it's not a Bourne-like shell */
return 0;
}
/* Write an error message describing the exit status given in
EXIT_CODE, EXIT_SIG, and COREDUMP, for the target TARGET_NAME.
Append "(ignored)" if IGNORED is nonzero. */
static void
child_error (struct child *child,
int exit_code, int exit_sig, int coredump, int ignored)
{
const char *pre = "*** ";
const char *post = "";
const char *dump = "";
const struct file *f = child->file;
const floc *flocp = &f->cmds->fileinfo;
const char *nm;
size_t l;
if (ignored && silent_flag)
return;
if (exit_sig && coredump)
dump = _(" (core dumped)");
if (ignored)
{
pre = "";
post = _(" (ignored)");
}
if (! flocp->filenm)
nm = _("<builtin>");
else
{
char *a = alloca (strlen (flocp->filenm) + 1 + 11 + 1);
sprintf (a, "%s:%lu", flocp->filenm, flocp->lineno + flocp->offset);
nm = a;
}
l = strlen (pre) + strlen (nm) + strlen (f->name) + strlen (post);
OUTPUT_SET (&child->output);
show_goal_error ();
if (exit_sig == 0)
error (NILF, l + INTSTR_LENGTH,
_("%s[%s: %s] Error %d%s"), pre, nm, f->name, exit_code, post);
else
{
const char *s = strsignal (exit_sig);
error (NILF, l + strlen (s) + strlen (dump),
"%s[%s: %s] %s%s%s", pre, nm, f->name, s, dump, post);
}
OUTPUT_UNSET ();
}
/* Handle a dead child. This handler may or may not ever be installed.
If we're using the jobserver feature without pselect(), we need it.
First, installing it ensures the read will interrupt on SIGCHLD. Second,
we close the dup'd read FD to ensure we don't enter another blocking read
without reaping all the dead children. In this case we don't need the
dead_children count.
If we don't have either waitpid or wait3, then make is unreliable, but we
use the dead_children count to reap children as best we can. */
static unsigned int dead_children = 0;
RETSIGTYPE
child_handler (int sig UNUSED)
{
++dead_children;
jobserver_signal ();
#ifdef __EMX__
/* The signal handler must called only once! */
signal (SIGCHLD, SIG_DFL);
#endif
}
extern pid_t shell_function_pid;
/* Reap all dead children, storing the returned status and the new command
state ('cs_finished') in the 'file' member of the 'struct child' for the
dead child, and removing the child from the chain. In addition, if BLOCK
nonzero, we block in this function until we've reaped at least one
complete child, waiting for it to die if necessary. If ERR is nonzero,
print an error message first. */
void
reap_children (int block, int err)
{
#ifndef WINDOWS32
WAIT_T status;
#endif
/* Initially, assume we have some. */
int reap_more = 1;
#ifdef WAIT_NOHANG
# define REAP_MORE reap_more
#else
# define REAP_MORE dead_children
#endif
/* As long as:
We have at least one child outstanding OR a shell function in progress,
AND
We're blocking for a complete child OR there are more children to reap
we'll keep reaping children. */
while ((children != 0 || shell_function_pid != 0)
&& (block || REAP_MORE))
{
unsigned int remote = 0;
pid_t pid;
int exit_code, exit_sig, coredump;
struct child *lastc, *c;
int child_failed;
int any_remote, any_local;
int dontcare;
if (err && block)
{
static int printed = 0;
/* We might block for a while, so let the user know why.
Only print this message once no matter how many jobs are left. */
fflush (stdout);
if (!printed)
O (error, NILF, _("*** Waiting for unfinished jobs...."));
printed = 1;
}
/* We have one less dead child to reap. As noted in
child_handler() above, this count is completely unimportant for
all modern, POSIX-y systems that support wait3() or waitpid().
The rest of this comment below applies only to early, broken
pre-POSIX systems. We keep the count only because... it's there...
The test and decrement are not atomic; if it is compiled into:
register = dead_children - 1;
dead_children = register;
a SIGCHLD could come between the two instructions.
child_handler increments dead_children.
The second instruction here would lose that increment. But the
only effect of dead_children being wrong is that we might wait
longer than necessary to reap a child, and lose some parallelism;
and we might print the "Waiting for unfinished jobs" message above
when not necessary. */
if (dead_children > 0)
--dead_children;
any_remote = 0;
any_local = shell_function_pid != 0;
for (c = children; c != 0; c = c->next)
{
any_remote |= c->remote;
any_local |= ! c->remote;
DB (DB_JOBS, (_("Live child %p (%s) PID %s %s\n"),
c, c->file->name, pid2str (c->pid),
c->remote ? _(" (remote)") : ""));
#ifdef VMS
break;
#endif
}
/* First, check for remote children. */
if (any_remote)
pid = remote_status (&exit_code, &exit_sig, &coredump, 0);
else
pid = 0;
if (pid > 0)
/* We got a remote child. */
remote = 1;
else if (pid < 0)
{
/* A remote status command failed miserably. Punt. */
remote_status_lose:
pfatal_with_name ("remote_status");
}
else
{
/* No remote children. Check for local children. */
#if !defined(__MSDOS__) && !defined(_AMIGA) && !defined(WINDOWS32)
if (any_local)
{
#ifdef VMS
/* Todo: This needs more untangling multi-process support */
/* Just do single child process support now */
vmsWaitForChildren (&status);
pid = c->pid;
/* VMS failure status can not be fully translated */
status = $VMS_STATUS_SUCCESS (c->cstatus) ? 0 : (1 << 8);
/* A Posix failure can be exactly translated */
if ((c->cstatus & VMS_POSIX_EXIT_MASK) == VMS_POSIX_EXIT_MASK)
status = (c->cstatus >> 3 & 255) << 8;
#else
#ifdef WAIT_NOHANG
if (!block)
pid = WAIT_NOHANG (&status);
else
#endif
EINTRLOOP (pid, wait (&status));
#endif /* !VMS */
}
else
pid = 0;
if (pid < 0)
{
/* The wait*() failed miserably. Punt. */
pfatal_with_name ("wait");
}
else if (pid > 0)
{
/* We got a child exit; chop the status word up. */
exit_code = WEXITSTATUS (status);
exit_sig = WIFSIGNALED (status) ? WTERMSIG (status) : 0;
coredump = WCOREDUMP (status);
/* If we have started jobs in this second, remove one. */
if (job_counter)
--job_counter;
}
else
{
/* No local children are dead. */
reap_more = 0;
if (!block || !any_remote)
break;
/* Now try a blocking wait for a remote child. */
pid = remote_status (&exit_code, &exit_sig, &coredump, 1);
if (pid < 0)
goto remote_status_lose;
else if (pid == 0)
/* No remote children either. Finally give up. */
break;
/* We got a remote child. */
remote = 1;
}
#endif /* !__MSDOS__, !Amiga, !WINDOWS32. */
#ifdef __MSDOS__
/* Life is very different on MSDOS. */
pid = dos_pid - 1;
status = dos_status;
exit_code = WEXITSTATUS (status);
if (exit_code == 0xff)
exit_code = -1;
exit_sig = WIFSIGNALED (status) ? WTERMSIG (status) : 0;
coredump = 0;
#endif /* __MSDOS__ */
#ifdef _AMIGA
/* Same on Amiga */
pid = amiga_pid - 1;
status = amiga_status;
exit_code = amiga_status;
exit_sig = 0;
coredump = 0;
#endif /* _AMIGA */
#ifdef WINDOWS32
{
HANDLE hPID;
HANDLE hcTID, hcPID;
DWORD dwWaitStatus = 0;
exit_code = 0;
exit_sig = 0;
coredump = 0;
/* Record the thread ID of the main process, so that we
could suspend it in the signal handler. */
if (!main_thread)
{
hcTID = GetCurrentThread ();
hcPID = GetCurrentProcess ();
if (!DuplicateHandle (hcPID, hcTID, hcPID, &main_thread, 0,
FALSE, DUPLICATE_SAME_ACCESS))
{
DWORD e = GetLastError ();
fprintf (stderr,
"Determine main thread ID (Error %ld: %s)\n",
e, map_windows32_error_to_string (e));
}
else
DB (DB_VERBOSE, ("Main thread handle = %p\n", main_thread));
}
/* wait for anything to finish */
hPID = process_wait_for_any (block, &dwWaitStatus);
if (hPID)
{
/* was an error found on this process? */
int werr = process_last_err (hPID);
/* get exit data */
exit_code = process_exit_code (hPID);
if (werr)
fprintf (stderr, "make (e=%d): %s", exit_code,
map_windows32_error_to_string (exit_code));
/* signal */
exit_sig = process_signal (hPID);
/* cleanup process */
process_cleanup (hPID);
coredump = 0;
}
else if (dwWaitStatus == WAIT_FAILED)
{
/* The WaitForMultipleObjects() failed miserably. Punt. */
pfatal_with_name ("WaitForMultipleObjects");
}
else if (dwWaitStatus == WAIT_TIMEOUT)
{
/* No child processes are finished. Give up waiting. */
reap_more = 0;
break;
}
pid = (pid_t) hPID;
}
#endif /* WINDOWS32 */
}
/* Check if this is the child of the 'shell' function. */
if (!remote && pid == shell_function_pid)
{
shell_completed (exit_code, exit_sig);
break;
}
/* Search for a child matching the deceased one. */
lastc = 0;
for (c = children; c != 0; lastc = c, c = c->next)
if (c->pid == pid && c->remote == remote)
break;
if (c == 0)
/* An unknown child died.
Ignore it; it was inherited from our invoker. */
continue;
/* Determine the failure status: 0 for success, 1 for updating target in
question mode, 2 for anything else. */
if (exit_sig == 0 && exit_code == 0)
child_failed = MAKE_SUCCESS;
else if (exit_sig == 0 && exit_code == 1 && question_flag && c->recursive)
child_failed = MAKE_TROUBLE;
else
child_failed = MAKE_FAILURE;
DB (DB_JOBS, (child_failed
? _("Reaping losing child %p PID %s %s\n")
: _("Reaping winning child %p PID %s %s\n"),
c, pid2str (c->pid), c->remote ? _(" (remote)") : ""));
if (c->sh_batch_file)
{
int rm_status;
DB (DB_JOBS, (_("Cleaning up temp batch file %s\n"),
c->sh_batch_file));
errno = 0;
rm_status = remove (c->sh_batch_file);
if (rm_status)
DB (DB_JOBS, (_("Cleaning up temp batch file %s failed (%d)\n"),
c->sh_batch_file, errno));
/* all done with memory */
free (c->sh_batch_file);
c->sh_batch_file = NULL;
}
/* If this child had the good stdin, say it is now free. */
if (c->good_stdin)
good_stdin_used = 0;
dontcare = c->dontcare;
if (child_failed && !c->noerror && !ignore_errors_flag)
{
/* The commands failed. Write an error message,
delete non-precious targets, and abort. */
static int delete_on_error = -1;
if (!dontcare && child_failed == MAKE_FAILURE)
child_error (c, exit_code, exit_sig, coredump, 0);
c->file->update_status = child_failed == MAKE_FAILURE ? us_failed : us_question;
if (delete_on_error == -1)
{
struct file *f = lookup_file (".DELETE_ON_ERROR");
delete_on_error = f != 0 && f->is_target;
}
if (exit_sig != 0 || delete_on_error)
delete_child_targets (c);
}
else
{
if (child_failed)
{
/* The commands failed, but we don't care. */
child_error (c, exit_code, exit_sig, coredump, 1);
child_failed = 0;
}
/* If there are more commands to run, try to start them. */
if (job_next_command (c))
{
if (handling_fatal_signal)
{
/* Never start new commands while we are dying.
Since there are more commands that wanted to be run,
the target was not completely remade. So we treat
this as if a command had failed. */
c->file->update_status = us_failed;
}
else
{
#ifndef NO_OUTPUT_SYNC
/* If we're sync'ing per line, write the previous line's
output before starting the next one. */
if (output_sync == OUTPUT_SYNC_LINE)
output_dump (&c->output);
#endif
/* Check again whether to start remotely.
Whether or not we want to changes over time.
Also, start_remote_job may need state set up
by start_remote_job_p. */
c->remote = start_remote_job_p (0);
start_job_command (c);
/* Fatal signals are left blocked in case we were
about to put that child on the chain. But it is
already there, so it is safe for a fatal signal to
arrive now; it will clean up this child's targets. */
unblock_sigs ();
if (c->file->command_state == cs_running)
/* We successfully started the new command.
Loop to reap more children. */
continue;
}
if (c->file->update_status != us_success)
/* We failed to start the commands. */
delete_child_targets (c);
}
else
/* There are no more commands. We got through them all
without an unignored error. Now the target has been
successfully updated. */
c->file->update_status = us_success;
}
/* When we get here, all the commands for c->file are finished. */
#ifndef NO_OUTPUT_SYNC
/* Synchronize any remaining parallel output. */
output_dump (&c->output);
#endif
/* At this point c->file->update_status is success or failed. But
c->file->command_state is still cs_running if all the commands
ran; notice_finish_file looks for cs_running to tell it that
it's interesting to check the file's modtime again now. */
if (! handling_fatal_signal)
/* Notice if the target of the commands has been changed.
This also propagates its values for command_state and
update_status to its also_make files. */
notice_finished_file (c->file);
DB (DB_JOBS, (_("Removing child %p PID %s%s from chain.\n"),
c, pid2str (c->pid), c->remote ? _(" (remote)") : ""));
/* Block fatal signals while frobnicating the list, so that
children and job_slots_used are always consistent. Otherwise
a fatal signal arriving after the child is off the chain and
before job_slots_used is decremented would believe a child was
live and call reap_children again. */
block_sigs ();
/* There is now another slot open. */
if (job_slots_used > 0)
--job_slots_used;
/* Remove the child from the chain and free it. */
if (lastc == 0)
children = c->next;
else
lastc->next = c->next;
free_child (c);
unblock_sigs ();
/* If the job failed, and the -k flag was not given, die,
unless we are already in the process of dying. */
if (!err && child_failed && !dontcare && !keep_going_flag &&
/* fatal_error_signal will die with the right signal. */
!handling_fatal_signal)
die (child_failed);
/* Only block for one child. */
block = 0;
}
return;
}
/* Free the storage allocated for CHILD. */
static void
free_child (struct child *child)
{
output_close (&child->output);
if (!jobserver_tokens)
ONS (fatal, NILF, "INTERNAL: Freeing child %p (%s) but no tokens left!\n",
child, child->file->name);
/* If we're using the jobserver and this child is not the only outstanding
job, put a token back into the pipe for it. */
if (jobserver_enabled () && jobserver_tokens > 1)
{
jobserver_release (1);
DB (DB_JOBS, (_("Released token for child %p (%s).\n"),
child, child->file->name));
}
--jobserver_tokens;
if (handling_fatal_signal) /* Don't bother free'ing if about to die. */
return;
if (child->command_lines != 0)
{
register unsigned int i;
for (i = 0; i < child->file->cmds->ncommand_lines; ++i)
free (child->command_lines[i]);
free (child->command_lines);
}
if (child->environment != 0)
{
register char **ep = child->environment;
while (*ep != 0)
free (*ep++);
free (child->environment);
}
free (child);
}
#ifdef POSIX
extern sigset_t fatal_signal_set;
#endif
void
block_sigs (void)
{
#ifdef POSIX
(void) sigprocmask (SIG_BLOCK, &fatal_signal_set, (sigset_t *) 0);
#else
# ifdef HAVE_SIGSETMASK
(void) sigblock (fatal_signal_mask);
# endif
#endif
}
#ifdef POSIX
void
unblock_sigs (void)
{
sigset_t empty;
sigemptyset (&empty);
sigprocmask (SIG_SETMASK, &empty, (sigset_t *) 0);
}
#endif
/* Start a job to run the commands specified in CHILD.
CHILD is updated to reflect the commands and ID of the child process.
NOTE: On return fatal signals are blocked! The caller is responsible
for calling 'unblock_sigs', once the new child is safely on the chain so
it can be cleaned up in the event of a fatal signal. */
static void
start_job_command (struct child *child)
{
int flags;
char *p;
#ifdef VMS
char *argv;
#else
char **argv;
#endif
/* If we have a completely empty commandset, stop now. */
if (!child->command_ptr)
goto next_command;
/* Combine the flags parsed for the line itself with
the flags specified globally for this target. */
flags = (child->file->command_flags
| child->file->cmds->lines_flags[child->command_line - 1]);
p = child->command_ptr;
child->noerror = ((flags & COMMANDS_NOERROR) != 0);
while (*p != '\0')
{
if (*p == '@')
flags |= COMMANDS_SILENT;
else if (*p == '+')
flags |= COMMANDS_RECURSE;
else if (*p == '-')
child->noerror = 1;
/* Don't skip newlines. */
else if (!ISBLANK (*p))
break;
++p;
}
child->recursive = ((flags & COMMANDS_RECURSE) != 0);
/* Update the file's command flags with any new ones we found. We only
keep the COMMANDS_RECURSE setting. Even this isn't 100% correct; we are
now marking more commands recursive than should be in the case of
multiline define/endef scripts where only one line is marked "+". In
order to really fix this, we'll have to keep a lines_flags for every
actual line, after expansion. */
child->file->cmds->lines_flags[child->command_line - 1] |= flags & COMMANDS_RECURSE;
/* POSIX requires that a recipe prefix after a backslash-newline should
be ignored. Remove it now so the output is correct. */
{
char prefix = child->file->cmds->recipe_prefix;
char *p1, *p2;
p1 = p2 = p;
while (*p1 != '\0')
{
*(p2++) = *p1;
if (p1[0] == '\n' && p1[1] == prefix)
++p1;
++p1;
}
*p2 = *p1;
}
/* Figure out an argument list from this command line. */
{
char *end = 0;
#ifdef VMS
/* Skip any leading whitespace */
while (*p)
{
if (!ISSPACE (*p))
{
if (*p != '\\')
break;
if ((p[1] != '\n') && (p[1] != 'n') && (p[1] != 't'))
break;
}
p++;
}
argv = p;
/* Although construct_command_argv contains some code for VMS, it was/is
not called/used. Please note, for VMS argv is a string (not an array
of strings) which contains the complete command line, which for
multi-line variables still includes the newlines. So detect newlines
and set 'end' (which is used for child->command_ptr) instead of
(re-)writing construct_command_argv */
if (!one_shell)
{
char *s = p;
int instring = 0;
while (*s)
{
if (*s == '"')
instring = !instring;
else if (*s == '\\' && !instring && *(s+1) != 0)
s++;
else if (*s == '\n' && !instring)
{
end = s;
break;
}
++s;
}
}
#else
argv = construct_command_argv (p, &end, child->file,
child->file->cmds->lines_flags[child->command_line - 1],
&child->sh_batch_file);
#endif
if (end == NULL)
child->command_ptr = NULL;
else
{
*end++ = '\0';
child->command_ptr = end;
}
}
/* If -q was given, say that updating 'failed' if there was any text on the
command line, or 'succeeded' otherwise. The exit status of 1 tells the
user that -q is saying 'something to do'; the exit status for a random
error is 2. */
if (argv != 0 && question_flag && !(flags & COMMANDS_RECURSE))
{
#ifndef VMS
free (argv[0]);
free (argv);
#endif
#ifdef VMS
/* On VMS, argv[0] can be a null string here */
if (argv[0] != 0)
{
#endif
child->file->update_status = us_question;
notice_finished_file (child->file);
return;
#ifdef VMS
}
#endif
}
if (touch_flag && !(flags & COMMANDS_RECURSE))
{
/* Go on to the next command. It might be the recursive one.
We construct ARGV only to find the end of the command line. */
#ifndef VMS
if (argv)
{
free (argv[0]);
free (argv);
}
#endif
argv = 0;
}
if (argv == 0)
{
next_command:
#ifdef __MSDOS__
execute_by_shell = 0; /* in case construct_command_argv sets it */
#endif
/* This line has no commands. Go to the next. */
if (job_next_command (child))
start_job_command (child);
else
{
/* No more commands. Make sure we're "running"; we might not be if
(e.g.) all commands were skipped due to -n. */
set_command_state (child->file, cs_running);
child->file->update_status = us_success;
notice_finished_file (child->file);
}
OUTPUT_UNSET();
return;
}
/* Are we going to synchronize this command's output? Do so if either we're
in SYNC_RECURSE mode or this command is not recursive. We'll also check
output_sync separately below in case it changes due to error. */
child->output.syncout = output_sync && (output_sync == OUTPUT_SYNC_RECURSE
|| !(flags & COMMANDS_RECURSE));
OUTPUT_SET (&child->output);
#ifndef NO_OUTPUT_SYNC
if (! child->output.syncout)
/* We don't want to sync this command: to avoid misordered
output ensure any already-synced content is written. */
output_dump (&child->output);
#endif
/* Print the command if appropriate. */
if (just_print_flag || trace_flag
|| (!(flags & COMMANDS_SILENT) && !silent_flag))
OS (message, 0, "%s", p);
/* Tell update_goal_chain that a command has been started on behalf of
this target. It is important that this happens here and not in
reap_children (where we used to do it), because reap_children might be
reaping children from a different target. We want this increment to
guaranteedly indicate that a command was started for the dependency
chain (i.e., update_file recursion chain) we are processing. */
++commands_started;
/* Optimize an empty command. People use this for timestamp rules,
so avoid forking a useless shell. Do this after we increment
commands_started so make still treats this special case as if it
performed some action (makes a difference as to what messages are
printed, etc. */
#if !defined(VMS) && !defined(_AMIGA)
if (
#if defined __MSDOS__ || defined (__EMX__)
unixy_shell /* the test is complicated and we already did it */
#else
(argv[0] && is_bourne_compatible_shell (argv[0]))
#endif
&& (argv[1] && argv[1][0] == '-'
&&
((argv[1][1] == 'c' && argv[1][2] == '\0')
||
(argv[1][1] == 'e' && argv[1][2] == 'c' && argv[1][3] == '\0')))
&& (argv[2] && argv[2][0] == ':' && argv[2][1] == '\0')
&& argv[3] == NULL)
{
free (argv[0]);
free (argv);
goto next_command;
}
#endif /* !VMS && !_AMIGA */
/* If -n was given, recurse to get the next line in the sequence. */
if (just_print_flag && !(flags & COMMANDS_RECURSE))
{
#ifndef VMS
free (argv[0]);
free (argv);
#endif
goto next_command;
}
/* We're sure we're going to invoke a command: set up the output. */
output_start ();
/* Flush the output streams so they won't have things written twice. */
fflush (stdout);
fflush (stderr);
/* Decide whether to give this child the 'good' standard input
(one that points to the terminal or whatever), or the 'bad' one
that points to the read side of a broken pipe. */
child->good_stdin = !good_stdin_used;
if (child->good_stdin)
good_stdin_used = 1;
child->deleted = 0;
#ifndef _AMIGA
/* Set up the environment for the child. */
if (child->environment == 0)
child->environment = target_environment (child->file);
#endif
#if !defined(__MSDOS__) && !defined(_AMIGA) && !defined(WINDOWS32)
#ifndef VMS
/* start_waiting_job has set CHILD->remote if we can start a remote job. */
if (child->remote)
{
int is_remote, id, used_stdin;
if (start_remote_job (argv, child->environment,
child->good_stdin ? 0 : get_bad_stdin (),
&is_remote, &id, &used_stdin))
/* Don't give up; remote execution may fail for various reasons. If
so, simply run the job locally. */
goto run_local;
else
{
if (child->good_stdin && !used_stdin)
{
child->good_stdin = 0;
good_stdin_used = 0;
}
child->remote = is_remote;
child->pid = id;
}
}
else
#endif /* !VMS */
{
/* Fork the child process. */
char **parent_environ;
run_local:
block_sigs ();
child->remote = 0;
#ifdef VMS
if (!child_execute_job (child, argv))
{
/* Fork failed! */
perror_with_name ("fork", "");
goto error;
}
#else
parent_environ = environ;
jobserver_pre_child (flags & COMMANDS_RECURSE);
child->pid = child_execute_job (&child->output, child->good_stdin, argv, child->environment);
environ = parent_environ; /* Restore value child may have clobbered. */
jobserver_post_child (flags & COMMANDS_RECURSE);
if (child->pid < 0)
{
/* Fork failed! */
unblock_sigs ();
perror_with_name ("fork", "");
goto error;
}
#endif /* !VMS */
}
#else /* __MSDOS__ or Amiga or WINDOWS32 */
#ifdef __MSDOS__
{
int proc_return;
block_sigs ();
dos_status = 0;
/* We call 'system' to do the job of the SHELL, since stock DOS
shell is too dumb. Our 'system' knows how to handle long
command lines even if pipes/redirection is needed; it will only
call COMMAND.COM when its internal commands are used. */
if (execute_by_shell)
{
char *cmdline = argv[0];
/* We don't have a way to pass environment to 'system',
so we need to save and restore ours, sigh... */
char **parent_environ = environ;
environ = child->environment;
/* If we have a *real* shell, tell 'system' to call
it to do everything for us. */
if (unixy_shell)
{
/* A *real* shell on MSDOS may not support long
command lines the DJGPP way, so we must use 'system'. */
cmdline = argv[2]; /* get past "shell -c" */
}
dos_command_running = 1;
proc_return = system (cmdline);
environ = parent_environ;
execute_by_shell = 0; /* for the next time */
}
else
{
dos_command_running = 1;
proc_return = spawnvpe (P_WAIT, argv[0], argv, child->environment);
}
/* Need to unblock signals before turning off
dos_command_running, so that child's signals
will be treated as such (see fatal_error_signal). */
unblock_sigs ();
dos_command_running = 0;
/* If the child got a signal, dos_status has its
high 8 bits set, so be careful not to alter them. */
if (proc_return == -1)
dos_status |= 0xff;
else
dos_status |= (proc_return & 0xff);
++dead_children;
child->pid = dos_pid++;
}
#endif /* __MSDOS__ */
#ifdef _AMIGA
amiga_status = MyExecute (argv);
++dead_children;
child->pid = amiga_pid++;
if (amiga_batch_file)
{
amiga_batch_file = 0;
DeleteFile (amiga_bname); /* Ignore errors. */
}
#endif /* Amiga */
#ifdef WINDOWS32
{
HANDLE hPID;
char* arg0;
int outfd = FD_STDOUT;
int errfd = FD_STDERR;
/* make UNC paths safe for CreateProcess -- backslash format */
arg0 = argv[0];
if (arg0 && arg0[0] == '/' && arg0[1] == '/')
for ( ; arg0 && *arg0; arg0++)
if (*arg0 == '/')
*arg0 = '\\';
/* make sure CreateProcess() has Path it needs */
sync_Path_environment ();
#ifndef NO_OUTPUT_SYNC
/* Divert child output if output_sync in use. */
if (child->output.syncout)
{
if (child->output.out >= 0)
outfd = child->output.out;
if (child->output.err >= 0)
errfd = child->output.err;
}
#else
outfd = errfd = -1;
#endif
hPID = process_easy (argv, child->environment, outfd, errfd);
if (hPID != INVALID_HANDLE_VALUE)
child->pid = (pid_t) hPID;
else
{
int i;
unblock_sigs ();
fprintf (stderr,
_("process_easy() failed to launch process (e=%ld)\n"),
process_last_err (hPID));
for (i = 0; argv[i]; i++)
fprintf (stderr, "%s ", argv[i]);
fprintf (stderr, _("\nCounted %d args in failed launch\n"), i);
goto error;
}
}
#endif /* WINDOWS32 */
#endif /* __MSDOS__ or Amiga or WINDOWS32 */
/* Bump the number of jobs started in this second. */
++job_counter;
/* We are the parent side. Set the state to
say the commands are running and return. */
set_command_state (child->file, cs_running);
/* Free the storage used by the child's argument list. */
#ifndef VMS
free (argv[0]);
free (argv);
#endif
OUTPUT_UNSET();
return;
error:
child->file->update_status = us_failed;
notice_finished_file (child->file);
OUTPUT_UNSET();
}
/* Try to start a child running.
Returns nonzero if the child was started (and maybe finished), or zero if
the load was too high and the child was put on the 'waiting_jobs' chain. */
static int
start_waiting_job (struct child *c)
{
struct file *f = c->file;
/* If we can start a job remotely, we always want to, and don't care about
the local load average. We record that the job should be started
remotely in C->remote for start_job_command to test. */
c->remote = start_remote_job_p (1);
/* If we are running at least one job already and the load average
is too high, make this one wait. */
if (!c->remote
&& ((job_slots_used > 0 && load_too_high ())
#ifdef WINDOWS32
|| process_table_full ()
#endif
))
{
/* Put this child on the chain of children waiting for the load average
to go down. */
set_command_state (f, cs_running);
c->next = waiting_jobs;
waiting_jobs = c;
return 0;
}
/* Start the first command; reap_children will run later command lines. */
start_job_command (c);
switch (f->command_state)
{
case cs_running:
c->next = children;
DB (DB_JOBS, (_("Putting child %p (%s) PID %s%s on the chain.\n"),
c, c->file->name, pid2str (c->pid),
c->remote ? _(" (remote)") : ""));
children = c;
/* One more job slot is in use. */
++job_slots_used;
unblock_sigs ();
break;
case cs_not_started:
/* All the command lines turned out to be empty. */
f->update_status = us_success;
/* FALLTHROUGH */
case cs_finished:
notice_finished_file (f);
free_child (c);
break;
default:
assert (f->command_state == cs_finished);
break;
}
return 1;
}
/* Create a 'struct child' for FILE and start its commands running. */
void
new_job (struct file *file)
{
struct commands *cmds = file->cmds;
struct child *c;
char **lines;
unsigned int i;
/* Let any previously decided-upon jobs that are waiting
for the load to go down start before this new one. */
start_waiting_jobs ();
/* Reap any children that might have finished recently. */
reap_children (0, 0);
/* Chop the commands up into lines if they aren't already. */
chop_commands (cmds);
/* Start the command sequence, record it in a new
'struct child', and add that to the chain. */
c = xcalloc (sizeof (struct child));
output_init (&c->output);
c->file = file;
c->sh_batch_file = NULL;
/* Cache dontcare flag because file->dontcare can be changed once we
return. Check dontcare inheritance mechanism for details. */
c->dontcare = file->dontcare;
/* Start saving output in case the expansion uses $(info ...) etc. */
OUTPUT_SET (&c->output);
/* Expand the command lines and store the results in LINES. */
lines = xmalloc (cmds->ncommand_lines * sizeof (char *));
for (i = 0; i < cmds->ncommand_lines; ++i)
{
/* Collapse backslash-newline combinations that are inside variable
or function references. These are left alone by the parser so
that they will appear in the echoing of commands (where they look
nice); and collapsed by construct_command_argv when it tokenizes.
But letting them survive inside function invocations loses because
we don't want the functions to see them as part of the text. */
char *in, *out, *ref;
/* IN points to where in the line we are scanning.
OUT points to where in the line we are writing.
When we collapse a backslash-newline combination,
IN gets ahead of OUT. */
in = out = cmds->command_lines[i];
while ((ref = strchr (in, '$')) != 0)
{
++ref; /* Move past the $. */
if (out != in)
/* Copy the text between the end of the last chunk
we processed (where IN points) and the new chunk
we are about to process (where REF points). */
memmove (out, in, ref - in);
/* Move both pointers past the boring stuff. */
out += ref - in;
in = ref;
if (*ref == '(' || *ref == '{')
{
char openparen = *ref;
char closeparen = openparen == '(' ? ')' : '}';
char *outref;
int count;
char *p;
*out++ = *in++; /* Copy OPENPAREN. */
outref = out;
/* IN now points past the opening paren or brace.
Count parens or braces until it is matched. */
count = 0;
while (*in != '\0')
{
if (*in == closeparen && --count < 0)
break;
else if (*in == '\\' && in[1] == '\n')
{
/* We have found a backslash-newline inside a
variable or function reference. Eat it and
any following whitespace. */
int quoted = 0;
for (p = in - 1; p > ref && *p == '\\'; --p)
quoted = !quoted;
if (quoted)
/* There were two or more backslashes, so this is
not really a continuation line. We don't collapse
the quoting backslashes here as is done in
collapse_continuations, because the line will
be collapsed again after expansion. */
*out++ = *in++;
else
{
/* Skip the backslash, newline, and whitespace. */
in += 2;
NEXT_TOKEN (in);
/* Discard any preceding whitespace that has
already been written to the output. */
while (out > outref && ISBLANK (out[-1]))
--out;
/* Replace it all with a single space. */
*out++ = ' ';
}
}
else
{
if (*in == openparen)
++count;
*out++ = *in++;
}
}
}
}
/* There are no more references in this line to worry about.
Copy the remaining uninteresting text to the output. */
if (out != in)
memmove (out, in, strlen (in) + 1);
/* Finally, expand the line. */
cmds->fileinfo.offset = i;
lines[i] = allocated_variable_expand_for_file (cmds->command_lines[i],
file);
}
cmds->fileinfo.offset = 0;
c->command_lines = lines;
/* Fetch the first command line to be run. */
job_next_command (c);
/* Wait for a job slot to be freed up. If we allow an infinite number
don't bother; also job_slots will == 0 if we're using the jobserver. */
if (job_slots != 0)
while (job_slots_used == job_slots)
reap_children (1, 0);
#ifdef MAKE_JOBSERVER
/* If we are controlling multiple jobs make sure we have a token before
starting the child. */
/* This can be inefficient. There's a decent chance that this job won't
actually have to run any subprocesses: the command script may be empty
or otherwise optimized away. It would be nice if we could defer
obtaining a token until just before we need it, in start_job_command.
To do that we'd need to keep track of whether we'd already obtained a
token (since start_job_command is called for each line of the job, not
just once). Also more thought needs to go into the entire algorithm;
this is where the old parallel job code waits, so... */
else if (jobserver_enabled ())
while (1)
{
int got_token;
DB (DB_JOBS, ("Need a job token; we %shave children\n",
children ? "" : "don't "));
/* If we don't already have a job started, use our "free" token. */
if (!jobserver_tokens)
break;
/* Prepare for jobserver token acquisition. */
jobserver_pre_acquire ();
/* Reap anything that's currently waiting. */
reap_children (0, 0);
/* Kick off any jobs we have waiting for an opportunity that
can run now (i.e., waiting for load). */
start_waiting_jobs ();
/* If our "free" slot is available, use it; we don't need a token. */
if (!jobserver_tokens)
break;
/* There must be at least one child already, or we have no business
waiting for a token. */
if (!children)
O (fatal, NILF, "INTERNAL: no children as we go to sleep on read\n");
/* Get a token. */
got_token = jobserver_acquire (waiting_jobs != NULL);
/* If we got one, we're done here. */
if (got_token == 1)
{
DB (DB_JOBS, (_("Obtained token for child %p (%s).\n"),
c, c->file->name));
break;
}
}
#endif
++jobserver_tokens;
/* Trace the build.
Use message here so that changes to working directories are logged. */
if (trace_flag)
{
char *newer = allocated_variable_expand_for_file ("$?", c->file);
const char *nm;
if (! cmds->fileinfo.filenm)
nm = _("<builtin>");
else
{
char *n = alloca (strlen (cmds->fileinfo.filenm) + 1 + 11 + 1);
sprintf (n, "%s:%lu", cmds->fileinfo.filenm, cmds->fileinfo.lineno);
nm = n;
}
if (newer[0] == '\0')
OSS (message, 0,
_("%s: target '%s' does not exist"), nm, c->file->name);
else
OSSS (message, 0,
_("%s: update target '%s' due to: %s"), nm, c->file->name, newer);
free (newer);
}
/* The job is now primed. Start it running.
(This will notice if there is in fact no recipe.) */
start_waiting_job (c);
if (job_slots == 1 || not_parallel)
/* Since there is only one job slot, make things run linearly.
Wait for the child to die, setting the state to 'cs_finished'. */
while (file->command_state == cs_running)
reap_children (1, 0);
OUTPUT_UNSET ();
return;
}
/* Move CHILD's pointers to the next command for it to execute.
Returns nonzero if there is another command. */
static int
job_next_command (struct child *child)
{
while (child->command_ptr == 0 || *child->command_ptr == '\0')
{
/* There are no more lines in the expansion of this line. */
if (child->command_line == child->file->cmds->ncommand_lines)
{
/* There are no more lines to be expanded. */
child->command_ptr = 0;
child->file->cmds->fileinfo.offset = 0;
return 0;
}
else
/* Get the next line to run. */
child->command_ptr = child->command_lines[child->command_line++];
}
child->file->cmds->fileinfo.offset = child->command_line - 1;
return 1;
}
/* Determine if the load average on the system is too high to start a new job.
The real system load average is only recomputed once a second. However, a
very parallel make can easily start tens or even hundreds of jobs in a
second, which brings the system to its knees for a while until that first
batch of jobs clears out.
To avoid this we use a weighted algorithm to try to account for jobs which
have been started since the last second, and guess what the load average
would be now if it were computed.
This algorithm was provided by Thomas Riedl <thomas.riedl@siemens.com>,
who writes:
! calculate something load-oid and add to the observed sys.load,
! so that latter can catch up:
! - every job started increases jobctr;
! - every dying job decreases a positive jobctr;
! - the jobctr value gets zeroed every change of seconds,
! after its value*weight_b is stored into the 'backlog' value last_sec
! - weight_a times the sum of jobctr and last_sec gets
! added to the observed sys.load.
!
! The two weights have been tried out on 24 and 48 proc. Sun Solaris-9
! machines, using a several-thousand-jobs-mix of cpp, cc, cxx and smallish
! sub-shelled commands (rm, echo, sed...) for tests.
! lowering the 'direct influence' factor weight_a (e.g. to 0.1)
! resulted in significant excession of the load limit, raising it
! (e.g. to 0.5) took bad to small, fast-executing jobs and didn't
! reach the limit in most test cases.
!
! lowering the 'history influence' weight_b (e.g. to 0.1) resulted in
! exceeding the limit for longer-running stuff (compile jobs in
! the .5 to 1.5 sec. range),raising it (e.g. to 0.5) overrepresented
! small jobs' effects.
*/
#define LOAD_WEIGHT_A 0.25
#define LOAD_WEIGHT_B 0.25
static int
load_too_high (void)
{
#if defined(__MSDOS__) || defined(VMS) || defined(_AMIGA) || defined(__riscos__)
return 1;
#else
static double last_sec;
static time_t last_now;
double load, guess;
time_t now;
#ifdef WINDOWS32
/* sub_proc.c is limited in the number of objects it can wait for. */
if (process_table_full ())
return 1;
#endif
if (max_load_average < 0)
return 0;
/* Find the real system load average. */
make_access ();
if (getloadavg (&load, 1) != 1)
{
static int lossage = -1;
/* Complain only once for the same error. */
if (lossage == -1 || errno != lossage)
{
if (errno == 0)
/* An errno value of zero means getloadavg is just unsupported. */
O (error, NILF,
_("cannot enforce load limits on this operating system"));
else
perror_with_name (_("cannot enforce load limit: "), "getloadavg");
}
lossage = errno;
load = 0;
}
user_access ();
/* If we're in a new second zero the counter and correct the backlog
value. Only keep the backlog for one extra second; after that it's 0. */
now = time (NULL);
if (last_now < now)
{
if (last_now == now - 1)
last_sec = LOAD_WEIGHT_B * job_counter;
else
last_sec = 0.0;
job_counter = 0;
last_now = now;
}
/* Try to guess what the load would be right now. */
guess = load + (LOAD_WEIGHT_A * (job_counter + last_sec));
DB (DB_JOBS, ("Estimated system load = %f (actual = %f) (max requested = %f)\n",
guess, load, max_load_average));
return guess >= max_load_average;
#endif
}
/* Start jobs that are waiting for the load to be lower. */
void
start_waiting_jobs (void)
{
struct child *job;
if (waiting_jobs == 0)
return;
do
{
/* Check for recently deceased descendants. */
reap_children (0, 0);
/* Take a job off the waiting list. */
job = waiting_jobs;
waiting_jobs = job->next;
/* Try to start that job. We break out of the loop as soon
as start_waiting_job puts one back on the waiting list. */
}
while (start_waiting_job (job) && waiting_jobs != 0);
return;
}
#ifndef WINDOWS32
/* EMX: Start a child process. This function returns the new pid. */
# if defined __EMX__
int
child_execute_job (struct output *out, int good_stdin, char **argv, char **envp)
{
int pid;
int fdin = good_stdin ? FD_STDIN : get_bad_stdin ();
int fdout = FD_STDOUT;
int fderr = FD_STDERR;
int save_fdin = -1;
int save_fdout = -1;
int save_fderr = -1;
/* Divert child output if we want to capture output. */
if (out && out->syncout)
{
if (out->out >= 0)
fdout = out->out;
if (out->err >= 0)
fderr = out->err;
}
/* For each FD which needs to be redirected first make a dup of the standard
FD to save and mark it close on exec so our child won't see it. Then
dup2() the standard FD to the redirect FD, and also mark the redirect FD
as close on exec. */
if (fdin != FD_STDIN)
{
save_fdin = dup (FD_STDIN);
if (save_fdin < 0)
O (fatal, NILF, _("no more file handles: could not duplicate stdin\n"));
CLOSE_ON_EXEC (save_fdin);
dup2 (fdin, FD_STDIN);
CLOSE_ON_EXEC (fdin);
}
if (fdout != FD_STDOUT)
{
save_fdout = dup (FD_STDOUT);
if (save_fdout < 0)
O (fatal, NILF,
_("no more file handles: could not duplicate stdout\n"));
CLOSE_ON_EXEC (save_fdout);
dup2 (fdout, FD_STDOUT);
CLOSE_ON_EXEC (fdout);
}
if (fderr != FD_STDERR)
{
if (fderr != fdout)
{
save_fderr = dup (FD_STDERR);
if (save_fderr < 0)
O (fatal, NILF,
_("no more file handles: could not duplicate stderr\n"));
CLOSE_ON_EXEC (save_fderr);
}
dup2 (fderr, FD_STDERR);
CLOSE_ON_EXEC (fderr);
}
/* Run the command. */
pid = exec_command (argv, envp);
/* Restore stdout/stdin/stderr of the parent and close temporary FDs. */
if (save_fdin >= 0)
{
if (dup2 (save_fdin, FD_STDIN) != FD_STDIN)
O (fatal, NILF, _("Could not restore stdin\n"));
else
close (save_fdin);
}
if (save_fdout >= 0)
{
if (dup2 (save_fdout, FD_STDOUT) != FD_STDOUT)
O (fatal, NILF, _("Could not restore stdout\n"));
else
close (save_fdout);
}
if (save_fderr >= 0)
{
if (dup2 (save_fderr, FD_STDERR) != FD_STDERR)
O (fatal, NILF, _("Could not restore stderr\n"));
else
close (save_fderr);
}
return pid;
}
#elif !defined (_AMIGA) && !defined (__MSDOS__) && !defined (VMS)
/* POSIX:
Create a child process executing the command in ARGV.
ENVP is the environment of the new program. Returns the PID or -1. */
int
child_execute_job (struct output *out, int good_stdin, char **argv, char **envp)
{
const int fdin = good_stdin ? FD_STDIN : get_bad_stdin ();
int fdout = FD_STDOUT;
int fderr = FD_STDERR;
int r;
int pid;
/* Divert child output if we want to capture it. */
if (out && out->syncout)
{
if (out->out >= 0)
fdout = out->out;
if (out->err >= 0)
fderr = out->err;
}
pid = vfork();
if (pid != 0)
return pid;
/* We are the child. */
unblock_sigs ();
#ifdef SET_STACK_SIZE
/* Reset limits, if necessary. */
if (stack_limit.rlim_cur)
setrlimit (RLIMIT_STACK, &stack_limit);
#endif
/* For any redirected FD, dup2() it to the standard FD.
They are all marked close-on-exec already. */
if (fdin >= 0 && fdin != FD_STDIN)
EINTRLOOP (r, dup2 (fdin, FD_STDIN));
if (fdout != FD_STDOUT)
EINTRLOOP (r, dup2 (fdout, FD_STDOUT));
if (fderr != FD_STDERR)
EINTRLOOP (r, dup2 (fderr, FD_STDERR));
/* Run the command. */
exec_command (argv, envp);
}
#endif /* !AMIGA && !__MSDOS__ && !VMS */
#endif /* !WINDOWS32 */
#ifndef _AMIGA
/* Replace the current process with one running the command in ARGV,
with environment ENVP. This function does not return. */
/* EMX: This function returns the pid of the child process. */
# ifdef __EMX__
int
# else
void
# endif
exec_command (char **argv, char **envp)
{
#ifdef VMS
/* to work around a problem with signals and execve: ignore them */
#ifdef SIGCHLD
signal (SIGCHLD,SIG_IGN);
#endif
/* Run the program. */
execve (argv[0], argv, envp);
perror_with_name ("execve: ", argv[0]);
_exit (EXIT_FAILURE);
#else
#ifdef WINDOWS32
HANDLE hPID;
HANDLE hWaitPID;
int exit_code = EXIT_FAILURE;
/* make sure CreateProcess() has Path it needs */
sync_Path_environment ();
/* launch command */
hPID = process_easy (argv, envp, -1, -1);
/* make sure launch ok */
if (hPID == INVALID_HANDLE_VALUE)
{
int i;
fprintf (stderr, _("process_easy() failed to launch process (e=%ld)\n"),
process_last_err (hPID));
for (i = 0; argv[i]; i++)
fprintf (stderr, "%s ", argv[i]);
fprintf (stderr, _("\nCounted %d args in failed launch\n"), i);
exit (EXIT_FAILURE);
}
/* wait and reap last child */
hWaitPID = process_wait_for_any (1, 0);
while (hWaitPID)
{
/* was an error found on this process? */
int err = process_last_err (hWaitPID);
/* get exit data */
exit_code = process_exit_code (hWaitPID);
if (err)
fprintf (stderr, "make (e=%d, rc=%d): %s",
err, exit_code, map_windows32_error_to_string (err));
/* cleanup process */
process_cleanup (hWaitPID);
/* expect to find only last pid, warn about other pids reaped */
if (hWaitPID == hPID)
break;
else
{
char *pidstr = xstrdup (pid2str ((pid_t)hWaitPID));
fprintf (stderr,
_("make reaped child pid %s, still waiting for pid %s\n"),
pidstr, pid2str ((pid_t)hPID));
free (pidstr);
}
}
/* return child's exit code as our exit code */
exit (exit_code);
#else /* !WINDOWS32 */
# ifdef __EMX__
int pid;
# endif
/* Be the user, permanently. */
child_access ();
# ifdef __EMX__
/* Run the program. */
pid = spawnvpe (P_NOWAIT, argv[0], argv, envp);
if (pid >= 0)
return pid;
/* the file might have a strange shell extension */
if (errno == ENOENT)
errno = ENOEXEC;
# else
/* Run the program. */
environ = envp;
execvp (argv[0], argv);
# endif /* !__EMX__ */
switch (errno)
{
case ENOENT:
/* We are in the child: don't use the output buffer.
It's not right to run fprintf() here! */
if (makelevel == 0)
fprintf (stderr, _("%s: %s: Command not found\n"), program, argv[0]);
else
fprintf (stderr, _("%s[%u]: %s: Command not found\n"),
program, makelevel, argv[0]);
break;
case ENOEXEC:
{
/* The file is not executable. Try it as a shell script. */
const char *shell;
char **new_argv;
int argc;
int i=1;
# ifdef __EMX__
/* Do not use $SHELL from the environment */
struct variable *p = lookup_variable ("SHELL", 5);
if (p)
shell = p->value;
else
shell = 0;
# else
shell = getenv ("SHELL");
# endif
if (shell == 0)
shell = default_shell;
argc = 1;
while (argv[argc] != 0)
++argc;
# ifdef __EMX__
if (!unixy_shell)
++argc;
# endif
new_argv = alloca ((1 + argc + 1) * sizeof (char *));
new_argv[0] = (char *)shell;
# ifdef __EMX__
if (!unixy_shell)
{
new_argv[1] = "/c";
++i;
--argc;
}
# endif
new_argv[i] = argv[0];
while (argc > 0)
{
new_argv[i + argc] = argv[argc];
--argc;
}
# ifdef __EMX__
pid = spawnvpe (P_NOWAIT, shell, new_argv, envp);
if (pid >= 0)
break;
# else
execvp (shell, new_argv);
# endif
if (errno == ENOENT)
OS (error, NILF, _("%s: Shell program not found"), shell);
else
perror_with_name ("execvp: ", shell);
break;
}
# ifdef __EMX__
case EINVAL:
/* this nasty error was driving me nuts :-( */
O (error, NILF, _("spawnvpe: environment space might be exhausted"));
/* FALLTHROUGH */
# endif
default:
perror_with_name ("execvp: ", argv[0]);
break;
}
# ifdef __EMX__
return pid;
# else
_exit (127);
# endif
#endif /* !WINDOWS32 */
#endif /* !VMS */
}
#else /* On Amiga */
void
exec_command (char **argv)
{
MyExecute (argv);
}
void clean_tmp (void)
{
DeleteFile (amiga_bname);
}
#endif /* On Amiga */
#ifndef VMS
/* Figure out the argument list necessary to run LINE as a command. Try to
avoid using a shell. This routine handles only ' quoting, and " quoting
when no backslash, $ or ' characters are seen in the quotes. Starting
quotes may be escaped with a backslash. If any of the characters in
sh_chars is seen, or any of the builtin commands listed in sh_cmds
is the first word of a line, the shell is used.
If RESTP is not NULL, *RESTP is set to point to the first newline in LINE.
If *RESTP is NULL, newlines will be ignored.
SHELL is the shell to use, or nil to use the default shell.
IFS is the value of $IFS, or nil (meaning the default).
FLAGS is the value of lines_flags for this command line. It is
used in the WINDOWS32 port to check whether + or $(MAKE) were found
in this command line, in which case the effect of just_print_flag
is overridden. */
static char **
construct_command_argv_internal (char *line, char **restp, const char *shell,
const char *shellflags, const char *ifs,
int flags, char **batch_filename UNUSED)
{
#ifdef __MSDOS__
/* MSDOS supports both the stock DOS shell and ports of Unixy shells.
We call 'system' for anything that requires ''slow'' processing,
because DOS shells are too dumb. When $SHELL points to a real
(unix-style) shell, 'system' just calls it to do everything. When
$SHELL points to a DOS shell, 'system' does most of the work
internally, calling the shell only for its internal commands.
However, it looks on the $PATH first, so you can e.g. have an
external command named 'mkdir'.
Since we call 'system', certain characters and commands below are
actually not specific to COMMAND.COM, but to the DJGPP implementation
of 'system'. In particular:
The shell wildcard characters are in DOS_CHARS because they will
not be expanded if we call the child via 'spawnXX'.
The ';' is in DOS_CHARS, because our 'system' knows how to run
multiple commands on a single line.
DOS_CHARS also include characters special to 4DOS/NDOS, so we
won't have to tell one from another and have one more set of
commands and special characters. */
static const char *sh_chars_dos = "*?[];|<>%^&()";
static const char *sh_cmds_dos[] =
{ "break", "call", "cd", "chcp", "chdir", "cls", "copy", "ctty", "date",
"del", "dir", "echo", "erase", "exit", "for", "goto", "if", "md",
"mkdir", "path", "pause", "prompt", "rd", "rmdir", "rem", "ren",
"rename", "set", "shift", "time", "type", "ver", "verify", "vol", ":",
0 };
static const char *sh_chars_sh = "#;\"*?[]&|<>(){}$`^";
static const char *sh_cmds_sh[] =
{ "cd", "echo", "eval", "exec", "exit", "login", "logout", "set", "umask",
"wait", "while", "for", "case", "if", ":", ".", "break", "continue",
"export", "read", "readonly", "shift", "times", "trap", "switch",
"unset", "ulimit", 0 };
const char *sh_chars;
const char **sh_cmds;
#elif defined (__EMX__)
static const char *sh_chars_dos = "*?[];|<>%^&()";
static const char *sh_cmds_dos[] =
{ "break", "call", "cd", "chcp", "chdir", "cls", "copy", "ctty", "date",
"del", "dir", "echo", "erase", "exit", "for", "goto", "if", "md",
"mkdir", "path", "pause", "prompt", "rd", "rmdir", "rem", "ren",
"rename", "set", "shift", "time", "type", "ver", "verify", "vol", ":",
0 };
static const char *sh_chars_os2 = "*?[];|<>%^()\"'&";
static const char *sh_cmds_os2[] =
{ "call", "cd", "chcp", "chdir", "cls", "copy", "date", "del", "detach",
"dir", "echo", "endlocal", "erase", "exit", "for", "goto", "if", "keys",
"md", "mkdir", "move", "path", "pause", "prompt", "rd", "rem", "ren",
"rename", "rmdir", "set", "setlocal", "shift", "start", "time", "type",
"ver", "verify", "vol", ":", 0 };
static const char *sh_chars_sh = "#;\"*?[]&|<>(){}$`^~'";
static const char *sh_cmds_sh[] =
{ "echo", "cd", "eval", "exec", "exit", "login", "logout", "set", "umask",
"wait", "while", "for", "case", "if", ":", ".", "break", "continue",
"export", "read", "readonly", "shift", "times", "trap", "switch",
"unset", 0 };
const char *sh_chars;
const char **sh_cmds;
#elif defined (_AMIGA)
static const char *sh_chars = "#;\"|<>()?*$`";
static const char *sh_cmds[] =
{ "cd", "eval", "if", "delete", "echo", "copy", "rename", "set", "setenv",
"date", "makedir", "skip", "else", "endif", "path", "prompt", "unset",
"unsetenv", "version", 0 };
#elif defined (WINDOWS32)
/* We used to have a double quote (") in sh_chars_dos[] below, but
that caused any command line with quoted file names be run
through a temporary batch file, which introduces command-line
limit of 4K charcaters imposed by cmd.exe. Since CreateProcess
can handle quoted file names just fine, removing the quote lifts
the limit from a very frequent use case, because using quoted
file names is commonplace on MS-Windows. */
static const char *sh_chars_dos = "|&<>";
static const char *sh_cmds_dos[] =
{ "assoc", "break", "call", "cd", "chcp", "chdir", "cls", "color", "copy",
"ctty", "date", "del", "dir", "echo", "echo.", "endlocal", "erase",
"exit", "for", "ftype", "goto", "if", "if", "md", "mkdir", "move",
"path", "pause", "prompt", "rd", "rem", "ren", "rename", "rmdir",
"set", "setlocal", "shift", "time", "title", "type", "ver", "verify",
"vol", ":", 0 };
static const char *sh_chars_sh = "#;\"*?[]&|<>(){}$`^";
static const char *sh_cmds_sh[] =
{ "cd", "eval", "exec", "exit", "login", "logout", "set", "umask", "wait",
"while", "for", "case", "if", ":", ".", "break", "continue", "export",
"read", "readonly", "shift", "times", "trap", "switch", "test",
#ifdef BATCH_MODE_ONLY_SHELL
"echo",
#endif
0 };
const char *sh_chars;
const char **sh_cmds;
#elif defined(__riscos__)
static const char *sh_chars = "";
static const char *sh_cmds[] = { 0 };
#else /* must be UNIX-ish */
static const char *sh_chars = "#;\"*?[]&|<>(){}$`^~!";
static const char *sh_cmds[] =
{ ".", ":", "break", "case", "cd", "continue", "eval", "exec", "exit",
"export", "for", "if", "login", "logout", "read", "readonly", "set",
"shift", "switch", "test", "times", "trap", "ulimit", "umask", "unset",
"wait", "while", 0 };
# ifdef HAVE_DOS_PATHS
/* This is required if the MSYS/Cygwin ports (which do not define
WINDOWS32) are compiled with HAVE_DOS_PATHS defined, which uses
sh_chars_sh directly (see below). The value must be identical
to that of sh_chars immediately above. */
static const char *sh_chars_sh = "#;\"*?[]&|<>(){}$`^~!";
# endif /* HAVE_DOS_PATHS */
#endif
int i;
char *p;
#ifndef NDEBUG
char *end;
#endif
char *ap;
const char *cap;
const char *cp;
int instring, word_has_equals, seen_nonequals, last_argument_was_empty;
char **new_argv = 0;
char *argstr = 0;
#ifdef WINDOWS32
int slow_flag = 0;
if (!unixy_shell)
{
sh_cmds = sh_cmds_dos;
sh_chars = sh_chars_dos;
}
else
{
sh_cmds = sh_cmds_sh;
sh_chars = sh_chars_sh;
}
#endif /* WINDOWS32 */
if (restp != NULL)
*restp = NULL;
/* Make sure not to bother processing an empty line but stop at newline. */
while (ISBLANK (*line))
++line;
if (*line == '\0')
return 0;
if (shellflags == 0)
shellflags = posix_pedantic ? "-ec" : "-c";
/* See if it is safe to parse commands internally. */
if (shell == 0)
shell = default_shell;
#ifdef WINDOWS32
else if (strcmp (shell, default_shell))
{
char *s1 = _fullpath (NULL, shell, 0);
char *s2 = _fullpath (NULL, default_shell, 0);
slow_flag = strcmp ((s1 ? s1 : ""), (s2 ? s2 : ""));
free (s1);
free (s2);
}
if (slow_flag)
goto slow;
#else /* not WINDOWS32 */
#if defined (__MSDOS__) || defined (__EMX__)
else if (strcasecmp (shell, default_shell))
{
extern int _is_unixy_shell (const char *_path);
DB (DB_BASIC, (_("$SHELL changed (was '%s', now '%s')\n"),
default_shell, shell));
unixy_shell = _is_unixy_shell (shell);
/* we must allocate a copy of shell: construct_command_argv() will free
* shell after this function returns. */
default_shell = xstrdup (shell);
}
if (unixy_shell)
{
sh_chars = sh_chars_sh;
sh_cmds = sh_cmds_sh;
}
else
{
sh_chars = sh_chars_dos;
sh_cmds = sh_cmds_dos;
# ifdef __EMX__
if (_osmode == OS2_MODE)
{
sh_chars = sh_chars_os2;
sh_cmds = sh_cmds_os2;
}
# endif
}
#else /* !__MSDOS__ */
else if (strcmp (shell, default_shell))
goto slow;
#endif /* !__MSDOS__ && !__EMX__ */
#endif /* not WINDOWS32 */
if (ifs)
for (cap = ifs; *cap != '\0'; ++cap)
if (*cap != ' ' && *cap != '\t' && *cap != '\n')
goto slow;
if (shellflags)
if (shellflags[0] != '-'
|| ((shellflags[1] != 'c' || shellflags[2] != '\0')
&& (shellflags[1] != 'e' || shellflags[2] != 'c' || shellflags[3] != '\0')))
goto slow;
i = strlen (line) + 1;
/* More than 1 arg per character is impossible. */
new_argv = xmalloc (i * sizeof (char *));
/* All the args can fit in a buffer as big as LINE is. */
ap = new_argv[0] = argstr = xmalloc (i);
#ifndef NDEBUG
end = ap + i;
#endif
/* I is how many complete arguments have been found. */
i = 0;
instring = word_has_equals = seen_nonequals = last_argument_was_empty = 0;
for (p = line; *p != '\0'; ++p)
{
assert (ap <= end);
if (instring)
{
/* Inside a string, just copy any char except a closing quote
or a backslash-newline combination. */
if (*p == instring)
{
instring = 0;
if (ap == new_argv[0] || *(ap-1) == '\0')
last_argument_was_empty = 1;
}
else if (*p == '\\' && p[1] == '\n')
{
/* Backslash-newline is handled differently depending on what
kind of string we're in: inside single-quoted strings you
keep them; in double-quoted strings they disappear. For
DOS/Windows/OS2, if we don't have a POSIX shell, we keep the
pre-POSIX behavior of removing the backslash-newline. */
if (instring == '"'
#if defined (__MSDOS__) || defined (__EMX__) || defined (WINDOWS32)
|| !unixy_shell
#endif
)
++p;
else
{
*(ap++) = *(p++);
*(ap++) = *p;
}
}
else if (*p == '\n' && restp != NULL)
{
/* End of the command line. */
*restp = p;
goto end_of_line;
}
/* Backslash, $, and ` are special inside double quotes.
If we see any of those, punt.
But on MSDOS, if we use COMMAND.COM, double and single
quotes have the same effect. */
else if (instring == '"' && strchr ("\\$`", *p) != 0 && unixy_shell)
goto slow;
#ifdef WINDOWS32
/* Quoted wildcard characters must be passed quoted to the
command, so give up the fast route. */
else if (instring == '"' && strchr ("*?", *p) != 0 && !unixy_shell)
goto slow;
else if (instring == '"' && strncmp (p, "\\\"", 2) == 0)
*ap++ = *++p;
#endif
else
*ap++ = *p;
}
else if (strchr (sh_chars, *p) != 0)
/* Not inside a string, but it's a special char. */
goto slow;
else if (one_shell && *p == '\n')
/* In .ONESHELL mode \n is a separator like ; or && */
goto slow;
#ifdef __MSDOS__
else if (*p == '.' && p[1] == '.' && p[2] == '.' && p[3] != '.')
/* '...' is a wildcard in DJGPP. */
goto slow;
#endif
else
/* Not a special char. */
switch (*p)
{
case '=':
/* Equals is a special character in leading words before the
first word with no equals sign in it. This is not the case
with sh -k, but we never get here when using nonstandard
shell flags. */
if (! seen_nonequals && unixy_shell)
goto slow;
word_has_equals = 1;
*ap++ = '=';
break;
case '\\':
/* Backslash-newline has special case handling, ref POSIX.
We're in the fastpath, so emulate what the shell would do. */
if (p[1] == '\n')
{
/* Throw out the backslash and newline. */
++p;
/* At the beginning of the argument, skip any whitespace other
than newline before the start of the next word. */
if (ap == new_argv[i])
while (ISBLANK (p[1]))
++p;
}
#ifdef WINDOWS32
/* Backslash before whitespace is not special if our shell
is not Unixy. */
else if (ISSPACE (p[1]) && !unixy_shell)
{
*ap++ = *p;
break;
}
#endif
else if (p[1] != '\0')
{
#ifdef HAVE_DOS_PATHS
/* Only remove backslashes before characters special to Unixy
shells. All other backslashes are copied verbatim, since
they are probably DOS-style directory separators. This
still leaves a small window for problems, but at least it
should work for the vast majority of naive users. */
#ifdef __MSDOS__
/* A dot is only special as part of the "..."
wildcard. */
if (strneq (p + 1, ".\\.\\.", 5))
{
*ap++ = '.';
*ap++ = '.';
p += 4;
}
else
#endif
if (p[1] != '\\' && p[1] != '\''
&& !ISSPACE (p[1])
&& strchr (sh_chars_sh, p[1]) == 0)
/* back up one notch, to copy the backslash */
--p;
#endif /* HAVE_DOS_PATHS */
/* Copy and skip the following char. */
*ap++ = *++p;
}
break;
case '\'':
case '"':
instring = *p;
break;
case '\n':
if (restp != NULL)
{
/* End of the command line. */
*restp = p;
goto end_of_line;
}
else
/* Newlines are not special. */
*ap++ = '\n';
break;
case ' ':
case '\t':
/* We have the end of an argument.
Terminate the text of the argument. */
*ap++ = '\0';
new_argv[++i] = ap;
last_argument_was_empty = 0;
/* Update SEEN_NONEQUALS, which tells us if every word
heretofore has contained an '='. */
seen_nonequals |= ! word_has_equals;
if (word_has_equals && ! seen_nonequals)
/* An '=' in a word before the first
word without one is magical. */
goto slow;
word_has_equals = 0; /* Prepare for the next word. */
/* If this argument is the command name,
see if it is a built-in shell command.
If so, have the shell handle it. */
if (i == 1)
{
register int j;
for (j = 0; sh_cmds[j] != 0; ++j)
{
if (streq (sh_cmds[j], new_argv[0]))
goto slow;
#if defined(__EMX__) || defined(WINDOWS32)
/* Non-Unix shells are case insensitive. */
if (!unixy_shell
&& strcasecmp (sh_cmds[j], new_argv[0]) == 0)
goto slow;
#endif
}
}
/* Skip whitespace chars, but not newlines. */
while (ISBLANK (p[1]))
++p;
break;
default:
*ap++ = *p;
break;
}
}
end_of_line:
if (instring)
/* Let the shell deal with an unterminated quote. */
goto slow;
/* Terminate the last argument and the argument list. */
*ap = '\0';
if (new_argv[i][0] != '\0' || last_argument_was_empty)
++i;
new_argv[i] = 0;
if (i == 1)