/* Command processing for GNU Make.
Copyright (C) 1988, 1989, 1991, 1992, 1993, 1994 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 2, 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 GNU Make; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "make.h"
#include "dep.h"
#include "commands.h"
#include "file.h"
#include "variable.h"
#include "job.h"

extern int remote_kill ();

#ifndef	HAVE_UNISTD_H
extern int getpid ();
#endif

/* Set FILE's automatic variables up.  */

static void
set_file_variables (file)
     register struct file *file;
{
  register char *p;
  char *at, *percent, *star, *less;

#ifndef	NO_ARCHIVES
  /* If the target is an archive member `lib(member)',
     then $@ is `lib' and $% is `member'.  */

  if (ar_name (file->name))
    {
      unsigned int len;
      p = index (file->name, '(');
      at = (char *) alloca (p - file->name + 1);
      bcopy (file->name, at, p - file->name);
      at[p - file->name] = '\0';
      len = strlen (p + 1);
      percent = (char *) alloca (len);
      bcopy (p + 1, percent, len - 1);
      percent[len - 1] = '\0';
    }
  else
#endif	/* NO_ARCHIVES.  */
    {
      at = file->name;
      percent = "";
    }

  /* $* is the stem from an implicit or static pattern rule.  */
  if (file->stem == 0)
    {
      /* In Unix make, $* is set to the target name with
	 any suffix in the .SUFFIXES list stripped off for
	 explicit rules.  We store this in the `stem' member.  */
      register struct dep *d;
      char *name;
      unsigned int len;

#ifndef	NO_ARCHIVES
      if (ar_name (file->name))
	{
	  name = index (file->name, '(') + 1;
	  len = strlen (name) - 1;
	}
      else
#endif
	{
	  name = file->name;
	  len = strlen (name);
	}

      for (d = enter_file (".SUFFIXES")->deps; d != 0; d = d->next)
	{
	  unsigned int slen = strlen (dep_name (d));
	  if (len > slen && !strncmp (dep_name (d), name + len - slen, slen))
	    {
	      file->stem = savestring (name, len - slen);
	      break;
	    }
	}
      if (d == 0)
	file->stem = "";
    }
  star = file->stem;

  /* $< is the first dependency.  */
  less = file->deps != 0 ? dep_name (file->deps) : "";

  if (file->cmds == default_file->cmds)
    /* This file got its commands from .DEFAULT.
       In this case $< is the same as $@.  */
    less = at;

#define	DEFINE_VARIABLE(name, len, value) \
  (void) define_variable_for_file (name, len, value, o_automatic, 0, file)

  /* Define the variables.  */

  DEFINE_VARIABLE ("<", 1, less);
  DEFINE_VARIABLE ("*", 1, star);
  DEFINE_VARIABLE ("@", 1, at);
  DEFINE_VARIABLE ("%", 1, percent);

  /* Make sure that no dependencies are repeated.  This does not
     really matter for the purpose of updating targets, but it
     might make some names be listed twice for $^ and $?.  */

  uniquize_deps (file->deps);

  /* Compute the values for $^ and $?.  */

  {
    register unsigned int caret_len, qmark_len;
    char *caret_value;
    register char *cp;
    char *qmark_value;
    register char *qp;
    register struct dep *d;
    unsigned int len;

    caret_len = qmark_len = 0;
    for (d = file->deps; d != 0; d = d->next)
      {
	register unsigned int i = strlen (dep_name (d)) + 1;
	caret_len += i;
	if (d->changed)
	  qmark_len += i;
      }

    len = caret_len == 0 ? 1 : caret_len;
    cp = caret_value = (char *) alloca (len);
    len = qmark_len == 0 ? 1 : qmark_len;
    qp = qmark_value = (char *) alloca (len);

    for (d = file->deps; d != 0; d = d->next)
      {
	char *c = dep_name (d);

#ifndef	NO_ARCHIVES
	if (ar_name (c))
	  {
	    c = index (c, '(') + 1;
	    len = strlen (c) - 1;
	  }
	else
#endif
	  len = strlen (c);

	bcopy (c, cp, len);
	cp += len;
	*cp++ = ' ';

	if (d->changed)
	  {
	    bcopy (c, qp, len);
	    qp += len;
	    *qp++ = ' ';
	  }
      }

    /* Kill the last spaces and define the variables.  */

    cp[cp > caret_value ? -1 : 0] = '\0';
    DEFINE_VARIABLE ("^", 1, caret_value);

    qp[qp > qmark_value ? -1 : 0] = '\0';
    DEFINE_VARIABLE ("?", 1, qmark_value);
  }

#undef	DEFINE_VARIABLE
}

/* Chop CMDS up into individual command lines if necessary.
   Also set the `lines_flag' and `any_recurse' members.  */

void
chop_commands (cmds)
     register struct commands *cmds;
{
  if (cmds != 0 && cmds->command_lines == 0)
    {
      /* Chop CMDS->commands up into lines in CMDS->command_lines.
	 Also set the corresponding CMDS->lines_flags elements,
	 and the CMDS->any_recurse flag.  */
      register char *p;
      unsigned int nlines, idx;
      char **lines;

      nlines = 5;
      lines = (char **) xmalloc (5 * sizeof (char *));
      idx = 0;
      p = cmds->commands;
      while (*p != '\0')
	{
	  char *end = p;
	find_end:;
	  end = index (end, '\n');
	  if (end == 0)
	    end = p + strlen (p);
	  else if (end > p && end[-1] == '\\')
	    {
	      int backslash = 1;
	      register char *b;
	      for (b = end - 2; b >= p && *b == '\\'; --b)
		backslash = !backslash;
	      if (backslash)
		{
		  ++end;
		  goto find_end;
		}
	    }

	  if (idx == nlines)
	    {
	      nlines += 2;
	      lines = (char **) xrealloc ((char *) lines,
					  nlines * sizeof (char *));
	    }
	  lines[idx++] = savestring (p, end - p);
	  p = end;
	  if (*p != '\0')
	    ++p;
	}

      if (idx != nlines)
	{
	  nlines = idx;
	  lines = (char **) xrealloc ((char *) lines,
				      nlines * sizeof (char *));
	}

      cmds->ncommand_lines = nlines;
      cmds->command_lines = lines;

      cmds->any_recurse = 0;
      cmds->lines_flags = (char *) xmalloc (nlines);
      for (idx = 0; idx < nlines; ++idx)
	{
	  int flags = 0;

	  for (p = lines[idx];
	       isblank (*p) || *p == '-' || *p == '@' || *p == '+';
	       ++p)
	    switch (*p)
	      {
	      case '+':
		flags |= COMMANDS_RECURSE;
		break;
	      case '@':
		flags |= COMMANDS_SILENT;
		break;
	      case '-':
		flags |= COMMANDS_NOERROR;
		break;
	      }
	  if (!(flags & COMMANDS_RECURSE))
	    {
	      unsigned int len = strlen (p);
	      if (sindex (p, len, "$(MAKE)", 7) != 0
		  || sindex (p, len, "${MAKE}", 7) != 0)
		flags |= COMMANDS_RECURSE;
	    }

	  cmds->lines_flags[idx] = flags;
	  cmds->any_recurse |= flags & COMMANDS_RECURSE;
	}
    }
}

/* Execute the commands to remake FILE.  If they are currently executing,
   return or have already finished executing, just return.  Otherwise,
   fork off a child process to run the first command line in the sequence.  */

void
execute_file_commands (file)
     struct file *file;
{
  register char *p;

  /* Don't go through all the preparations if
     the commands are nothing but whitespace.  */

  for (p = file->cmds->commands; *p != '\0'; ++p)
    if (!isspace (*p) && *p != '-' && *p != '@')
      break;
  if (*p == '\0')
    {
      /* We are all out of commands.
	 If we have gotten this far, all the previous commands
	 have run successfully, so we have winning update status.  */
      file->update_status = 0;
      notice_finished_file (file);
      return;
    }

  /* First set the automatic variables according to this file.  */

  initialize_file_variables (file);

  set_file_variables (file);

  /* Start the commands running.  */
  new_job (file);
}

/* This is set while we are inside fatal_error_signal,
   so things can avoid nonreentrant operations.  */

int handling_fatal_signal = 0;

/* Handle fatal signals.  */

RETSIGTYPE
fatal_error_signal (sig)
     int sig;
{
  handling_fatal_signal = 1;

  /* Set the handling for this signal to the default.
     It is blocked now while we run this handler.  */
  signal (sig, SIG_DFL);

  /* A termination signal won't be sent to the entire
     process group, but it means we want to kill the children.  */

  if (sig == SIGTERM)
    {
      register struct child *c;
      for (c = children; c != 0; c = c->next)
	if (!c->remote)
	  (void) kill (c->pid, SIGTERM);
    }

  /* If we got a signal that means the user
     wanted to kill make, remove pending targets.  */

  if (sig == SIGTERM || sig == SIGINT || sig == SIGHUP || sig == SIGQUIT)
    {
      register struct child *c;

      /* Remote children won't automatically get signals sent
	 to the process group, so we must send them.  */
      for (c = children; c != 0; c = c->next)
	if (c->remote)
	  (void) remote_kill (c->pid, sig);

      for (c = children; c != 0; c = c->next)
	delete_child_targets (c);

      /* Clean up the children.  We don't just use the call below because
	 we don't want to print the "Waiting for children" message.  */
      while (job_slots_used > 0)
	reap_children (1, 0);
    }
  else
    /* Wait for our children to die.  */
    while (job_slots_used > 0)
      reap_children (1, 1);

  /* Delete any non-precious intermediate files that were made.  */

  remove_intermediates (1);

  if (sig == SIGQUIT)
    /* We don't want to send ourselves SIGQUIT, because it will
       cause a core dump.  Just exit instead.  */
    exit (1);

  /* Signal the same code; this time it will really be fatal.  The signal
     will be unblocked when we return and arrive then to kill us.  */
  if (kill (getpid (), sig) < 0)
    pfatal_with_name ("kill");
}

/* Delete FILE unless it's precious or not actually a file (phony),
   and it has changed on disk since we last stat'd it.  */

static void
delete_target (file, on_behalf_of)
     struct file *file;
     char *on_behalf_of;
{
  struct stat st;

  if (file->precious || file->phony)
    return;

#ifndef NO_ARCHIVES
  if (ar_name (file->name))
    {
      if (ar_member_date (file->name) != file->last_mtime)
	{
	  if (on_behalf_of)
	    error ("*** [%s] Archive member `%s' may be bogus; not deleted",
		   on_behalf_of, file->name);
	  else
	    error ("*** Archive member `%s' may be bogus; not deleted",
		   file->name);
	}
      return;
    }
#endif

  if (stat (file->name, &st) == 0
      && S_ISREG (st.st_mode)
      && (time_t) st.st_mtime != file->last_mtime)
    {
      if (on_behalf_of)
	error ("*** [%s] Deleting file `%s'", on_behalf_of, file->name);
      else
	error ("*** Deleting file `%s'", file->name);
      if (unlink (file->name) < 0)
	perror_with_name ("unlink: ", file->name);
    }
}
     

/* Delete all non-precious targets of CHILD unless they were already deleted.
   Set the flag in CHILD to say they've been deleted.  */

void
delete_child_targets (child)
     struct child *child;
{
  struct dep *d;

  if (child->deleted)
    return;

  /* Delete the target file if it changed.  */
  delete_target (child->file, (char *) 0);

  /* Also remove any non-precious targets listed in the `also_make' member.  */
  for (d = child->file->also_make; d != 0; d = d->next)
    delete_target (d->file, child->file->name);

  child->deleted = 1;
}

/* Print out the commands in CMDS.  */

void
print_commands (cmds)
     register struct commands *cmds;
{
  register char *s;

  fputs ("#  commands to execute", stdout);

  if (cmds->filename == 0)
    puts (" (built-in):");
  else
    printf (" (from `%s', line %u):\n", cmds->filename, cmds->lineno);

  s = cmds->commands;
  while (*s != '\0')
    {
      char *end;

      while (isspace (*s))
	++s;

      end = index (s, '\n');
      if (end == 0)
	end = s + strlen (s);

      printf ("\t%.*s\n", (int) (end - s), s);

      s = end;
    }
}