job.c

早期freebsd实现

/*
 * Copyright (c) 1988, 1989, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)job.c	8.2 (Berkeley) 3/19/94";
#endif /* not lint */

/*-
 * job.c --
 *	handle the creation etc. of our child processes.
 *
 * Interface:
 *	Job_Make  	    	Start the creation of the given target.
 *
 *	Job_CatchChildren   	Check for and handle the termination of any
 *	    	  	    	children. This must be called reasonably
 *	    	  	    	frequently to keep the whole make going at
 *	    	  	    	a decent clip, since job table entries aren't
 *	    	  	    	removed until their process is caught this way.
 *	    	  	    	Its single argument is TRUE if the function
 *	    	  	    	should block waiting for a child to terminate.
 *
 *	Job_CatchOutput	    	Print any output our children have produced.
 *	    	  	    	Should also be called fairly frequently to
 *	    	  	    	keep the user informed of what's going on.
 *	    	  	    	If no output is waiting, it will block for
 *	    	  	    	a time given by the SEL_* constants, below,
 *	    	  	    	or until output is ready.
 *
 *	Job_Init  	    	Called to intialize this module. in addition,
 *	    	  	    	any commands attached to the .BEGIN target
 *	    	  	    	are executed before this function returns.
 *	    	  	    	Hence, the makefile must have been parsed
 *	    	  	    	before this function is called.
 *
 *	Job_Full  	    	Return TRUE if the job table is filled.
 *
 *	Job_Empty 	    	Return TRUE if the job table is completely
 *	    	  	    	empty.
 *
 *	Job_ParseShell	    	Given the line following a .SHELL target, parse
 *	    	  	    	the line as a shell specification. Returns
 *	    	  	    	FAILURE if the spec was incorrect.
 *
 *	Job_End	  	    	Perform any final processing which needs doing.
 *	    	  	    	This includes the execution of any commands
 *	    	  	    	which have been/were attached to the .END
 *	    	  	    	target. It should only be called when the
 *	    	  	    	job table is empty.
 *
 *	Job_AbortAll	    	Abort all currently running jobs. It doesn't
 *	    	  	    	handle output or do anything for the jobs,
 *	    	  	    	just kills them. It should only be called in
 *	    	  	    	an emergency, as it were.
 *
 *	Job_CheckCommands   	Verify that the commands for a target are
 *	    	  	    	ok. Provide them if necessary and possible.
 *
 *	Job_Touch 	    	Update a target without really updating it.
 *
 *	Job_Wait  	    	Wait for all currently-running jobs to finish.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/wait.h>

#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>

#include "make.h"
#include "hash.h"
#include "dir.h"
#include "job.h"
#include "pathnames.h"

extern int  errno;

/*
 * error handling variables 
 */
static int     	errors = 0;	    /* number of errors reported */
static int    	aborting = 0;	    /* why is the make aborting? */
#define ABORT_ERROR	1   	    /* Because of an error */
#define ABORT_INTERRUPT	2   	    /* Because it was interrupted */
#define ABORT_WAIT	3   	    /* Waiting for jobs to finish */


/*
 * post-make command processing. The node postCommands is really just the
 * .END target but we keep it around to avoid having to search for it
 * all the time.
 */
static GNode   	  *postCommands;    /* node containing commands to execute when
				     * everything else is done */
static int     	  numCommands; 	    /* The number of commands actually printed
				     * for a target. Should this number be
				     * 0, no shell will be executed. */


/*
 * Return values from JobStart.
 */
#define JOB_RUNNING	0   	/* Job is running */
#define JOB_ERROR 	1   	/* Error in starting the job */
#define JOB_FINISHED	2   	/* The job is already finished */
#define JOB_STOPPED	3   	/* The job is stopped */

/*
 * tfile is the name of a file into which all shell commands are put. It is
 * used over by removing it before the child shell is executed. The XXXXX in
 * the string are replaced by the pid of the make process in a 5-character
 * field with leading zeroes. 
 */
static char     tfile[] = TMPPAT;


/*
 * Descriptions for various shells.
 */
static Shell    shells[] = {
    /*
     * CSH description. The csh can do echo control by playing
     * with the setting of the 'echo' shell variable. Sadly,
     * however, it is unable to do error control nicely.
     */
{
    "csh",
    TRUE, "unset verbose", "set verbose", "unset verbose", 10,
    FALSE, "echo \"%s\"\n", "csh -c \"%s || exit 0\"",
    "v", "e",
},
    /*
     * SH description. Echo control is also possible and, under
     * sun UNIX anyway, one can even control error checking.
     */
{
    "sh",
    TRUE, "set -", "set -v", "set -", 5,
    FALSE, "echo \"%s\"\n", "sh -c '%s || exit 0'\n",
    "v", "e",
},
    /*
     * UNKNOWN.
     */
{
    (char *)0,
    FALSE, (char *)0, (char *)0, (char *)0, 0,
    FALSE, (char *)0, (char *)0,
    (char *)0, (char *)0,
}
};
static Shell 	*commandShell = &shells[DEFSHELL];/* this is the shell to
						   * which we pass all
						   * commands in the Makefile.
						   * It is set by the
						   * Job_ParseShell function */
static char   	*shellPath = (char *) NULL,	  /* full pathname of
						   * executable image */
               	*shellName;	      	      	  /* last component of shell */


static int  	maxJobs;    	/* The most children we can run at once */
static int  	maxLocal;    	/* The most local ones we can have */
static int     	nJobs;	    	/* The number of children currently running */
static int  	nLocal;    	/* The number of local children */
static Lst     	jobs;		/* The structures that describe them */
static Boolean	jobFull;    	/* Flag to tell when the job table is full. It
				 * is set TRUE when (1) the total number of
				 * running jobs equals the maximum allowed or
				 * (2) a job can only be run locally, but
				 * nLocal equals maxLocal */
#ifndef RMT_WILL_WATCH
static fd_set  	outputs;    	/* Set of descriptors of pipes connected to
				 * the output channels of children */
#endif

static GNode   	*lastNode;	/* The node for which output was most recently
				 * produced. */
static char    	*targFmt;   	/* Format string to use to head output from a
				 * job when it's not the most-recent job heard
				 * from */
#define TARG_FMT  "--- %s ---\n" /* Default format */

/*
 * When JobStart attempts to run a job remotely but can't, and isn't allowed
 * to run the job locally, or when Job_CatchChildren detects a job that has
 * been migrated home, the job is placed on the stoppedJobs queue to be run
 * when the next job finishes. 
 */
static Lst    stoppedJobs;	/* Lst of Job structures describing
				 * jobs that were stopped due to concurrency
				 * limits or migration home */


#if defined(USE_PGRP) && defined(SYSV)
#define KILL(pid,sig)	killpg (-(pid),(sig))
#else
# if defined(USE_PGRP)
#define KILL(pid,sig)	killpg ((pid),(sig))
# else
#define KILL(pid,sig)	kill ((pid),(sig))
# endif
#endif

static int JobCondPassSig __P((Job *, int));
static void JobPassSig __P((int));
static int JobCmpPid __P((Job *, int));
static int JobPrintCommand __P((char *, Job *));
static int JobSaveCommand __P((char *, GNode *));
static void JobFinish __P((Job *, union wait));
static void JobExec __P((Job *, char **));
static void JobMakeArgv __P((Job *, char **));
static void JobRestart __P((Job *));
static int JobStart __P((GNode *, int, Job *));
static void JobDoOutput __P((Job *, Boolean));
static Shell *JobMatchShell __P((char *));
static void JobInterrupt __P((int));

/*-
 *-----------------------------------------------------------------------
 * JobCondPassSig --
 *	Pass a signal to a job if the job is remote or if USE_PGRP
 *	is defined.
 *
 * Results:
 *	=== 0
 *
 * Side Effects:
 *	None, except the job may bite it.
 *
 *-----------------------------------------------------------------------
 */
static int
JobCondPassSig(job, signo)
    Job	    	*job;	    /* Job to biff */
    int	    	signo;	    /* Signal to send it */
{
#ifdef RMT_WANTS_SIGNALS
    if (job->flags & JOB_REMOTE) {
	(void)Rmt_Signal(job, signo);
    } else {
	KILL(job->pid, signo);
    }
#else
    /*
     * Assume that sending the signal to job->pid will signal any remote
     * job as well.
     */
    KILL(job->pid, signo);
#endif
    return(0);
}

/*-
 *-----------------------------------------------------------------------
 * JobPassSig --
 *	Pass a signal on to all remote jobs and to all local jobs if
 *	USE_PGRP is defined, then die ourselves.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	We die by the same signal.
 *	
 *-----------------------------------------------------------------------
 */
static void
JobPassSig(signo)
    int	    signo;	/* The signal number we've received */
{
    int	    mask;
    
    Lst_ForEach(jobs, JobCondPassSig, (ClientData)signo);

    /*
     * Deal with proper cleanup based on the signal received. We only run
     * the .INTERRUPT target if the signal was in fact an interrupt. The other
     * three termination signals are more of a "get out *now*" command.
     */
    if (signo == SIGINT) {
	JobInterrupt(TRUE);
    } else if ((signo == SIGHUP) || (signo == SIGTERM) || (signo == SIGQUIT)) {
	JobInterrupt(FALSE);
    }
    
    /*
     * Leave gracefully if SIGQUIT, rather than core dumping.
     */
    if (signo == SIGQUIT) {
	Finish(0);
    }
    
    /*
     * Send ourselves the signal now we've given the message to everyone else.
     * Note we block everything else possible while we're getting the signal.
     * This ensures that all our jobs get continued when we wake up before
     * we take any other signal.
     */
    mask = sigblock(0);
    (void) sigsetmask(~0 & ~(1 << (signo-1)));
    signal(signo, SIG_DFL);

    kill(getpid(), signo);

    Lst_ForEach(jobs, JobCondPassSig, (ClientData)SIGCONT);

    sigsetmask(mask);
    signal(signo, JobPassSig);

}

/*-
 *-----------------------------------------------------------------------
 * JobCmpPid  --
 *	Compare the pid of the job with the given pid and return 0 if they
 *	are equal. This function is called from Job_CatchChildren via
 *	Lst_Find to find the job descriptor of the finished job.
 *
 * Results:
 *	0 if the pid's match
 *
 * Side Effects:
 *	None
 *-----------------------------------------------------------------------
 */
static int
JobCmpPid (job, pid)
    int             pid;	/* process id desired */
    Job            *job;	/* job to examine */
{
    return (pid - job->pid);
}

/*-
 *-----------------------------------------------------------------------
 * JobPrintCommand  --
 *	Put out another command for the given job. If the command starts
 *	with an @ or a - we process it specially. In the former case,
 *	so long as the -s and -n flags weren't given to make, we stick
 *	a shell-specific echoOff command in the script. In the latter,
 *	we ignore errors for the entire job, unless the shell has error
 *	control.
 *	If the command is just "..." we take all future commands for this
 *	job to be commands to be executed once the entire graph has been
 *	made and return non-zero to signal that the end of the commands
 *	was reached. These commands are later attached to the postCommands
 *	node and executed by Job_End when all things are done.
 *	This function is called from JobStart via Lst_ForEach.
 *
 * Results:
 *	Always 0, unless the command was "..."
 *
 * Side Effects:
 *	If the command begins with a '-' and the shell has no error control,
 *	the JOB_IGNERR flag is set in the job descriptor.
 *	If the command is "..." and we're not ignoring such things,
 *	tailCmds is set to the successor node of the cmd.
 *	numCommands is incremented if the command is actually printed.
 *-----------------------------------------------------------------------
 */
static int
JobPrintCommand (cmd, job)
    char     	  *cmd;	    	    /* command string to print */
    Job           *job;	    	    /* job for which to print it */
{
    Boolean	  noSpecials;	    /* true if we shouldn't worry about
				     * inserting special commands into
				     * the input stream. */
    Boolean       shutUp = FALSE;   /* true if we put a no echo command
				     * into the command file */
    Boolean	  errOff = FALSE;   /* true if we turned error checking
				     * off before printing the command
				     * and need to turn it back on */
    char       	  *cmdTemplate;	    /* Template to use when printing the
				     * command */
    char    	  *cmdStart;	    /* Start of expanded command */
    LstNode 	  cmdNode;  	    /* Node for replacing the command */

    noSpecials = (noExecute && ! (job->node->type & OP_MAKE));

    if (strcmp (cmd, "...") == 0) {
	job->node->type |= OP_SAVE_CMDS; 
	if ((job->flags & JOB_IGNDOTS) == 0) {
	    job->tailCmds = Lst_Succ (Lst_Member (job->node->commands,
						  (ClientData)cmd));
	    return (1);
	}
	return (0);
    }

#define DBPRINTF(fmt, arg) if (DEBUG(JOB)) printf (fmt, arg); fprintf (job->cmdFILE, fmt, arg)

    numCommands += 1;

    /*
     * For debugging, we replace each command with the result of expanding
     * the variables in the command.
     */
    cmdNode = Lst_Member (job->node->commands, (ClientData)cmd);
    cmdStart = cmd = Var_Subst (NULL, cmd, job->node, FALSE);
    Lst_Replace (cmdNode, (ClientData)cmdStart);

    cmdTemplate = "%s\n";

    /*
     * Check for leading @' and -'s to control echoing and error checking.
     */
    while (*cmd == '@' || *cmd == '-') {
	if (*cmd == '@') {
	    shutUp = TRUE;