/* $XConsortium: parse.c,v 1.30 94/04/17 20:10:38 gildea Exp $ */
/*

Copyright (c) 1993, 1994  X Consortium

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of the X Consortium shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from the X Consortium.

*/

#include "def.h"

extern char	*directives[];
extern struct inclist	maininclist;

void overlap_strcpy(char* dest, char* src)
{
  while ((*dest++ = *src++));
}


int find_includes(struct filepointer *filep,
                  struct inclist     *file,
                  struct inclist     *file_red,
                  int		      recursion,
                  boolean	      failOK)
{
	register char	*line;
	register int	type;
	boolean recfailOK;

	while ((line = get_line(filep))) {
		switch(type = deftype(line, filep, file_red, file, TRUE)) {
		case IF:
		doif:
			type = find_includes(filep, file,
				file_red, recursion+1, failOK);
			while ((type == ELIF) || (type == ELIFFALSE) ||
			       (type == ELIFGUESSFALSE))
				type = gobble(filep, file, file_red);
			if (type == ELSE)
				gobble(filep, file, file_red);
			break;
		case IFFALSE:
		case IFGUESSFALSE:
		    doiffalse:
			if (type == IFGUESSFALSE || type == ELIFGUESSFALSE)
			    recfailOK = TRUE;
			else
			    recfailOK = failOK;
			type = gobble(filep, file, file_red);
			if (type == ELSE)
			    find_includes(filep, file,
					  file_red, recursion+1, recfailOK);
			else
			if (type == ELIF)
			    goto doif;
			else
			if ((type == ELIFFALSE) || (type == ELIFGUESSFALSE))
			    goto doiffalse;
			break;
		case IFDEF:
		case IFNDEF:
			if ((type == IFDEF && isdefined(line, file_red, NULL))
			 || (type == IFNDEF && !isdefined(line, file_red, NULL))) {
				debug(1,(type == IFNDEF ?
				    "line %d: %s !def'd in %s via %s%s\n" : "",
				    filep->f_line, line,
				    file->i_file, file_red->i_file, ": doit"));
				type = find_includes(filep, file,
					file_red, recursion+1, failOK);
				while (type == ELIF || type == ELIFFALSE || type == ELIFGUESSFALSE)
					type = gobble(filep, file, file_red);
				if (type == ELSE)
					gobble(filep, file, file_red);
			}
			else {
				debug(1,(type == IFDEF ?
				    "line %d: %s !def'd in %s via %s%s\n" : "",
				    filep->f_line, line,
				    file->i_file, file_red->i_file, ": gobble"));
				type = gobble(filep, file, file_red);
				if (type == ELSE)
					find_includes(filep, file,
						file_red, recursion+1, failOK);
				else if (type == ELIF)
				    	goto doif;
				else if (type == ELIFFALSE || type == ELIFGUESSFALSE)
				    	goto doiffalse;
			}
			break;
		case ELSE:
		case ELIFFALSE:
		case ELIFGUESSFALSE:
		case ELIF:
			if (!recursion)
				gobble(filep, file, file_red);
		case ENDIF:
			if (recursion)
				return(type);
		case DEFINE:
			define(line, file);
			break;
		case UNDEF:
			if (!*line) {
			    warning("%s, line %d: incomplete undef == \"%s\"\n",
				file_red->i_file, filep->f_line, line);
			    break;
			}
			undefine(line, file_red);
			break;
		case INCLUDE:
			add_include(filep, file, file_red, line, FALSE, failOK);
			break;
		case INCLUDEDOT:
			add_include(filep, file, file_red, line, TRUE, failOK);
			break;
		case ERROR:
		  /*
		    	warning("(from %s) %s: %d: %s\n",
				file_red->i_file, file->i_file,
				 filep->f_line, line);
		  */
		    	break;
		    
		case PRAGMA:
		case IDENT:
		case SCCS:
		case EJECT:
			break;
		case -1:
			warning("%s", file_red->i_file);
			if (file_red != file)
			    warning1(" (reading %s)", file->i_file);
			warning1(", line %d: unknown directive == \"%s\"\n",
				 filep->f_line, line);
			break;
		case -2:
			warning("%s", file_red->i_file);
			if (file_red != file)
			    warning1(" (reading %s)", file->i_file);
			warning1(", line %d: incomplete include == \"%s\"\n",
				 filep->f_line, line);
			break;
		}
	}
	return(-1);
}

int gobble(struct filepointer *filep,
           struct inclist *file,
           struct inclist *file_red)
{
	register char	*line;
	register int	type;

	while ((line = get_line(filep))) {
		switch(type = deftype(line, filep, file_red, file, FALSE)) {
		case IF:
		case IFFALSE:
		case IFGUESSFALSE:
		case IFDEF:
		case IFNDEF:
			type = gobble(filep, file, file_red);
			while ((type == ELIF) || (type == ELIFFALSE) ||
			       (type == ELIFGUESSFALSE))
			    type = gobble(filep, file, file_red);
			if (type == ELSE)
			        (void)gobble(filep, file, file_red);
			break;
		case ELSE:
		case ENDIF:
			debug(0,("%s, line %d: #%s\n",
				file->i_file, filep->f_line,
				directives[type]));
			return(type);
		case DEFINE:
		case UNDEF:
		case INCLUDE:
		case INCLUDEDOT:
		case PRAGMA:
		case ERROR:
		case IDENT:
		case SCCS:
		case EJECT:
			break;
		case ELIF:
		case ELIFFALSE:
		case ELIFGUESSFALSE:
			return(type);
		case -1:
			warning("%s, line %d: unknown directive == \"%s\"\n",
				file_red->i_file, filep->f_line, line);
			break;
		}
	}
	return(-1);
}

/*
 * Decide what type of # directive this line is.
 */
int deftype (char *line,
             struct filepointer *filep,
             struct inclist *file_red,
             struct inclist *file,
             int parse_it)
{
	register char	*p;
	char	*directive, savechar;
	register int	ret;

	/*
	 * Parse the directive...
	 */
	directive=line+1;
	while (*directive == ' ' || *directive == '\t')
		directive++;

	p = directive;
	while (*p >= 'a' && *p <= 'z')
		p++;
	savechar = *p;
	*p = '\0';
	ret = match(directive, directives);
	*p = savechar;

	/* If we don't recognize this compiler directive or we happen to just
	 * be gobbling up text while waiting for an #endif or #elif or #else
	 * in the case of an #elif we must check the zero_value and return an
	 * ELIF or an ELIFFALSE.
	 */

	if (ret == ELIF && !parse_it)
	{
	    while (*p == ' ' || *p == '\t')
		p++;
	    /*
	     * parse an expression.
	     */
	    debug(0,("%s, line %d: #elif %s ",
		   file->i_file, filep->f_line, p));
	    ret = zero_value(p, filep, file_red);
	    if (ret != IF)
	    {
		debug(0,("false...\n"));
		if (ret == IFFALSE)
		    return(ELIFFALSE);
		else
		    return(ELIFGUESSFALSE);
	    }
	    else
	    {
		debug(0,("true...\n"));
		return(ELIF);
	    }
	}

	if (ret < 0 || ! parse_it)
		return(ret);

	/*
	 * now decide how to parse the directive, and do it.
	 */
	while (*p == ' ' || *p == '\t')
		p++;
	switch (ret) {
	case IF:
		/*
		 * parse an expression.
		 */
		ret = zero_value(p, filep, file_red);
		debug(0,("%s, line %d: %s #if %s\n",
			 file->i_file, filep->f_line, ret?"false":"true", p));
		break;
	case IFDEF:
	case IFNDEF:
		debug(0,("%s, line %d: #%s %s\n",
			file->i_file, filep->f_line, directives[ret], p));
	case UNDEF:
		/*
		 * separate the name of a single symbol.
		 */
		while (isalnum(*p) || *p == '_')
			*line++ = *p++;
		*line = '\0';
		break;
	case INCLUDE:
		debug(2,("%s, line %d: #include %s\n",
			file->i_file, filep->f_line, p));

		/* Support ANSI macro substitution */
		{
		    struct symtab *sym = isdefined(p, file_red, NULL);
		    while (sym) {
			p = sym->s_value;
			debug(3,("%s : #includes SYMBOL %s = %s\n",
			       file->i_incstring,
			       sym -> s_name,
			       sym -> s_value));
			/* mark file as having included a 'soft include' */
			file->i_included_sym = TRUE; 
			sym = isdefined(p, file_red, NULL);
		    }
		}

		/*
		 * Separate the name of the include file.
		 */
		while (*p && *p != '"' && *p != '<')
			p++;
		if (! *p)
			return(-2);
		if (*p++ == '"') {
			ret = INCLUDEDOT;
			while (*p && *p != '"')
				*line++ = *p++;
		} else
			while (*p && *p != '>')
				*line++ = *p++;
		*line = '\0';
		break;
	case DEFINE:
		/*
		 * copy the definition back to the beginning of the line.
		 */
		overlap_strcpy (line, p);
		break;
	case ELSE:
	case ENDIF:
	case ELIF:
	case PRAGMA:
	case ERROR:
	case IDENT:
	case SCCS:
	case EJECT:
		debug(0,("%s, line %d: #%s\n",
			file->i_file, filep->f_line, directives[ret]));
		/*
		 * nothing to do.
		 */
		break;
	}
	return(ret);
}

struct symtab *isdefined(char *symbol,
                         struct inclist *file,
                         struct inclist **srcfile)
{
	register struct symtab	*val;

	if ((val = slookup(symbol, &maininclist))) {
		debug(1,("%s defined on command line\n", symbol));
		if (srcfile != NULL) *srcfile = &maininclist;
		return(val);
	}
	if ((val = fdefined(symbol, file, srcfile)))
		return(val);
	debug(1,("%s not defined in %s\n", symbol, file->i_file));
	return(NULL);
}

struct symtab *fdefined(char *symbol,
                        struct inclist *file,
                        struct inclist **srcfile)
{
	register struct inclist	**ip;
	register struct symtab	*val;
	register int	i;

	if (file->i_defchecked)
		return(NULL);
	file->i_defchecked = TRUE;
	if ((val = slookup(symbol, file)))
		debug(1,("%s defined in %s as %s\n", symbol, file->i_file, val->s_value));
	if (val == NULL && file->i_list)
		{
		for (ip = file->i_list, i=0; i < file->i_listlen; i++, ip++)
                  if ((val = fdefined(symbol, *ip, srcfile))) {
				break;
			}
		}
	else if (val != NULL && srcfile != NULL) *srcfile = file;
	file->i_defchecked = FALSE;

	return(val);
}

/*
 * Return type based on if the #if expression evaluates to 0
 */
int zero_value(char *exp,
               struct filepointer *filep,
               struct inclist *file_red)
{
	if (cppsetup(exp, filep, file_red))
	    return(IFFALSE);
	else
	    return(IF);
}

void define(char *def, struct inclist *file)
{
    char *val;

    /* Separate symbol name and its value */
    val = def;
    while (isalnum(*val) || *val == '_')
	val++;
    if (*val)
	*val++ = '\0';
    while (*val == ' ' || *val == '\t')
	val++;

    if (!*val)
	val = "1";
    define2(def, val, file);
}

void define2(char *name, char *val, struct inclist *file)
{
    int first, last, below;
    register struct symtab *sp = NULL, *dest;

    /* Make space if it's needed */
    if (file->i_defs == NULL)
    {
	file->i_defs = (struct symtab *)
			malloc(sizeof (struct symtab) * SYMTABINC);
	file->i_deflen = SYMTABINC;
	file->i_ndefs = 0;
    }
    else if (file->i_ndefs == file->i_deflen)
	file->i_defs = (struct symtab *)
			realloc(file->i_defs,
			    sizeof(struct symtab)*(file->i_deflen+=SYMTABINC));

    if (file->i_defs == NULL)
	fatalerr("malloc()/realloc() failure in insert_defn()\n");

    below = first = 0;
    last = file->i_ndefs - 1;
    while (last >= first)
    {
	/* Fast inline binary search */
	register char *s1;
	register char *s2;
	register int middle = (first + last) / 2;

	/* Fast inline strchr() */
	s1 = name;
	s2 = file->i_defs[middle].s_name;
	while (*s1++ == *s2++)
	    if (s2[-1] == '\0') break;

	/* If exact match, set sp and break */
	if (*--s1 == *--s2) 
	{
	    sp = file->i_defs + middle;
	    break;
	}

	/* If name > i_defs[middle] ... */
	if (*s1 > *s2) 
	{
	    below = first;
	    first = middle + 1;
	}
	/* else ... */
	else
	{
	    below = last = middle - 1;
	}
    }

    /* Search is done.  If we found an exact match to the symbol name,
       just replace its s_value */
    if (sp != NULL)
    {
	free(sp->s_value);
	sp->s_value = copy(val);
	return;
    }

    sp = file->i_defs + file->i_ndefs++;
    dest = file->i_defs + below + 1;
    while (sp > dest)
    {
	*sp = sp[-1];
	sp--;
    }
    sp->s_name = copy(name);
    sp->s_value = copy(val);
}

struct symtab *slookup(char *symbol, struct inclist *file)
{
	register int first = 0;
	register int last = file->i_ndefs - 1;

	if (file) while (last >= first)
	{
	    /* Fast inline binary search */
	    register char *s1;
	    register char *s2;
	    register int middle = (first + last) / 2;

	    /* Fast inline strchr() */
	    s1 = symbol;
	    s2 = file->i_defs[middle].s_name;
	    while (*s1++ == *s2++)
	        if (s2[-1] == '\0') break;

	    /* If exact match, we're done */
	    if (*--s1 == *--s2) 
	    {
	        return file->i_defs + middle;
	    }

	    /* If symbol > i_defs[middle] ... */
	    if (*s1 > *s2) 
	    {
	        first = middle + 1;
	    }
	    /* else ... */
	    else
	    {
	        last = middle - 1;
	    }
	}
	return(NULL);
}

void undefine(char *symbol, struct inclist *file)
{
	register struct symtab *ptr;
	struct inclist *srcfile;
	while ((ptr = isdefined(symbol, file, &srcfile)) != NULL)
	{
	    srcfile->i_ndefs--;
	    for (; ptr < srcfile->i_defs + srcfile->i_ndefs; ptr++)
		*ptr = ptr[1];
	}
}
