command.c

C++的一个好库。。。现在很流行

/*
 * Copyright 1993, 1995 Christopher Seiwald.
 *
 * This file is part of Jam - see jam.c for Copyright information.
 */

/*  This file is ALSO:
 *  Copyright 2001-2004 David Abrahams.
 *  Distributed under the Boost Software License, Version 1.0.
 *  (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
 */

/*
 * command.c - maintain lists of commands
 */

# include "jam.h"

# include "lists.h"
# include "parse.h"
# include "variable.h"
# include "rules.h"

# include "command.h"
# include <limits.h>
# include <string.h>

/*
 * cmd_new() - return a new CMD or 0 if too many args
 */

CMD *
cmd_new(
	RULE	*rule,
	LIST	*targets,
	LIST	*sources,
	LIST	*shell )
{
    CMD *cmd = (CMD *)malloc( sizeof( CMD ) );
    /* lift line-length limitation entirely when JAMSHELL is just "%" */
    int no_limit = ( shell && !strcmp(shell->string,"%") && !list_next(shell) );
    int max_line = MAXLINE;
    int allocated = -1;

    cmd->rule = rule;
    cmd->shell = shell;
    cmd->next = 0;

    lol_init( &cmd->args );
    lol_add( &cmd->args, targets );
    lol_add( &cmd->args, sources );
    cmd->buf = 0;

    do
    {
        free(cmd->buf); /* free any buffer from previous iteration */
        
        cmd->buf = (char*)malloc(max_line + 1);
        
        if (cmd->buf == 0)
            break;
        
        allocated = var_string( rule->actions->command, cmd->buf, max_line, &cmd->args );
        
        max_line = max_line * 2;
    }
    while( allocated < 0 && max_line < INT_MAX / 2 );

    if ( !no_limit )
    {
        /* Bail if the result won't fit in MAXLINE */
        char *s = cmd->buf;
        while ( *s )
        {
            size_t l = strcspn( s, "\n" );
            
            if ( l > MAXLINE )
            {
                /* We don't free targets/sources/shell if bailing. */
                cmd_free( cmd );
                return 0;
            }
            
            s += l;
            if ( *s )
                ++s;
        }
    }

    return cmd;
}

/*
 * cmd_free() - free a CMD
 */

void
cmd_free( CMD *cmd )
{
	lol_free( &cmd->args );
	list_free( cmd->shell );
    free( cmd->buf );
	free( (char *)cmd );
}