/*
 * Copyright 1994 Christopher Seiwald.
 *
 * This file is part of Jam - see jam.c for Copyright information.
 */

/*
 * command.h - the CMD structure and routines to manipulate them
 *
 * Both ACTION and CMD contain a rule, targets, and sources.  An
 * ACTION describes a rule to be applied to the given targets and
 * sources; a CMD is what actually gets executed by the shell.  The
 * differences are due to:
 *
 *  ACTIONS must be combined if 'actions together' is given.
 *  ACTIONS must be split if 'actions piecemeal' is given.
 *  ACTIONS must have current sources omitted for 'actions updated'.
 *
 * The CMD datatype holds a single command that is to be executed
 * against a target, and they can chain together to represent the
 * full collection of commands used to update a target.
 *
 * Structures:
 *
 *  CMD - an action, ready to be formatted into a buffer and executed.
 *
 * External routines:
 *
 *  cmd_new() - return a new CMD or 0 if too many args.
 *  cmd_free() - delete CMD and its parts.
 *  cmd_next() - walk the CMD chain.
 */


/*
 * CMD - an action, ready to be formatted into a buffer and executed.
 */

typedef struct _cmd CMD;

struct _cmd
{
    CMD  * next;
    CMD  * tail;   /* valid on in head */
    RULE * rule;   /* rule->actions contains shell script */
    LIST * shell;  /* $(SHELL) value */
    LOL    args;   /* LISTs for $(<), $(>) */
    char * buf;    /* actual commands */
};

CMD * cmd_new
(
    RULE * rule,     /* rule (referenced) */
    LIST * targets,  /* $(<) (freed) */
    LIST * sources,  /* $(>) (freed) */
    LIST * shell     /* $(SHELL) (freed) */
);

void cmd_free( CMD * );

#define cmd_next( c ) ( ( c )->next )