/*
 * Copyright 1993, 2000 Christopher Seiwald.
 *
 * This file is part of Jam - see jam.c for Copyright information.
 */
/*  This file is ALSO:
 *  (C) Copyright David Abrahams 2001. Permission to copy, use,
 *  modify, sell and distribute this software is granted provided this
 *  copyright notice appears in all copies. This software is provided
 *  "as is" without express or implied warranty, and with no claim as
 *  to its suitability for any purpose.
 */

# include "jam.h"
# include "lists.h"
# include "parse.h"
# include "compile.h"
# include "rules.h"
# include "variable.h"
# include "regexp.h"
# include "headers.h"
# include "hdrmacro.h"
# include "newstr.h"

/*
 * headers.c - handle #includes in source files
 *
 * Using regular expressions provided as the variable $(HDRSCAN), 
 * headers() searches a file for #include files and phonies up a
 * rule invocation:
 * 
 *	$(HDRRULE) <target> : <include files> ;
 *
 * External routines:
 *    headers() - scan a target for include files and call HDRRULE
 *
 * Internal routines:
 *    headers1() - using regexp, scan a file and build include LIST
 *
 * 04/13/94 (seiwald) - added shorthand L0 for null list pointer
 * 09/10/00 (seiwald) - replaced call to compile_rule with evaluate_rule,
 *		so that headers() doesn't have to mock up a parse structure
 *		just to invoke a rule.
 */

static LIST *headers1( LIST *l, char *file, int rec, regexp *re[],
                       regexp*  re_macros );

/*
 * headers() - scan a target for include files and call HDRRULE
 */

# define MAXINC 10

void
headers( TARGET *t )
{
    LIST	*hdrscan;
    LIST	*hdrrule;
    LIST	*headlist = 0;
    regexp	*re[ MAXINC ];
    int	rec = 0;
        
    /* the following regexp is used to detect cases where a  */
    /* file is included through a line line "#include MACRO" */
    static regexp *re_macros = 0;
    if ( re_macros == 0 )
    {
        re_macros = regex_compile(
            "^[ 	]*#[ 	]*include[ 	]*([A-Za-z][A-Za-z0-9_]*).*$" );
    }

    if( !( hdrscan = var_get( "HDRSCAN" ) ) || 
        !( hdrrule = var_get( "HDRRULE" ) ) )
        return;

    if( DEBUG_HEADER )
        printf( "header scan %s\n", t->name );

    /* Compile all regular expressions in HDRSCAN */

    while( rec < MAXINC && hdrscan )
    {
        re[rec++] = regex_compile( hdrscan->string );
        hdrscan = list_next( hdrscan );
    }

    /* Doctor up call to HDRRULE rule */
    /* Call headers1() to get LIST of included files. */
    {
        FRAME	frame[1];
        frame_init( frame );
        lol_add( frame->args, list_new( L0, t->name ) );
        lol_add( frame->args, headers1( headlist, t->boundname, rec, re, re_macros ) );

        if( lol_get( frame->args, 1 ) )
            evaluate_rule( hdrrule->string, frame );

        /* Clean up */

        frame_free( frame );
    }
}

/*
 * headers1() - using regexp, scan a file and build include LIST
 */

static LIST *
headers1( 
	LIST	*l,
	char	*file,
	int	rec,
	regexp	*re[],
        regexp  *re_macros )
{
	FILE	*f;
	char	buf[ 1024 ];
	int		i;

	if( !( f = fopen( file, "r" ) ) )
	    return l;

	while( fgets( buf, sizeof( buf ), f ) )
	{
	    for( i = 0; i < rec; i++ )
		if( regexec( re[i], buf ) && re[i]->startp[1] )
	    {
		re[i]->endp[1][0] = '\0';

		if( DEBUG_HEADER )
		    printf( "header found: %s\n", re[i]->startp[1] );

		l = list_new( l, newstr( re[i]->startp[1] ) );
	    }
            
            /* special treatment for #include MACRO */
            if ( regexec( re_macros, buf ) && re_macros->startp[1] )
            {
              char*  header_filename;
              
              re_macros->endp[1][0] = '\0';
              
              if ( DEBUG_HEADER )
                printf( "macro header found: %s", re_macros->startp[1] );
                
              header_filename = macro_header_get( re_macros->startp[1] );
              if (header_filename)
              {
	        if ( DEBUG_HEADER )
                  printf( " resolved to '%s'\n", header_filename );
                l = list_new( l, newstr( header_filename ) );
              }
              else
              {
	        if ( DEBUG_HEADER )
                  printf( " ignored !!\n" );
              }
            }
	}

	fclose( f );

	return l;
}

void
regerror( char *s )
{
	printf( "re error %s\n", s );
}