/*
   * Copyright 2007 Jon Loeliger, Freescale Semiconductor, Inc.
   *
   * This program 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 of the
   * License, or (at your option) any later version.
   *
   *  This program 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 this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
   *                                                                   USA
   */

  #define _GNU_SOURCE
  
  #include <stdio.h>

  #include "dtc.h"
  #include "srcpos.h"

  /* A node in our list of directories to search for source/include files */
  struct search_path {
  	struct search_path *next;	/* next node in list, NULL for end */
  	const char *dirname;		/* name of directory to search */
  };
  
  /* This is the list of directories that we search for source files */
  static struct search_path *search_path_head, **search_path_tail;

  static char *get_dirname(const char *path)

  {
  	const char *slash = strrchr(path, '/');
  
  	if (slash) {
  		int len = slash - path;
  		char *dir = xmalloc(len + 1);
  
  		memcpy(dir, path, len);
  		dir[len] = '\0';
  		return dir;
  	}
  	return NULL;
  }

  FILE *depfile; /* = NULL */

  struct srcfile_state *current_srcfile; /* = NULL */

  /* Detect infinite include recursion. */
  #define MAX_SRCFILE_DEPTH     (100)
  static int srcfile_depth; /* = 0 */

  
  /**
   * Try to open a file in a given directory.
   *
   * If the filename is an absolute path, then dirname is ignored. If it is a
   * relative path, then we look in that directory for the file.
   *
   * @param dirname	Directory to look in, or NULL for none
   * @param fname		Filename to look for
   * @param fp		Set to NULL if file did not open
   * @return allocated filename on success (caller must free), NULL on failure
   */
  static char *try_open(const char *dirname, const char *fname, FILE **fp)
  {
  	char *fullname;
  
  	if (!dirname || fname[0] == '/')
  		fullname = xstrdup(fname);
  	else
  		fullname = join_path(dirname, fname);

  	*fp = fopen(fullname, "rb");

  	if (!*fp) {
  		free(fullname);
  		fullname = NULL;
  	}
  
  	return fullname;
  }
  
  /**
   * Open a file for read access
   *
   * If it is a relative filename, we search the full search path for it.
   *
   * @param fname	Filename to open
   * @param fp	Returns pointer to opened FILE, or NULL on failure
   * @return pointer to allocated filename, which caller must free
   */
  static char *fopen_any_on_path(const char *fname, FILE **fp)
  {
  	const char *cur_dir = NULL;
  	struct search_path *node;
  	char *fullname;
  
  	/* Try current directory first */
  	assert(fp);
  	if (current_srcfile)
  		cur_dir = current_srcfile->dir;
  	fullname = try_open(cur_dir, fname, fp);
  
  	/* Failing that, try each search path in turn */
  	for (node = search_path_head; !*fp && node; node = node->next)
  		fullname = try_open(node->dirname, fname, fp);
  
  	return fullname;
  }

  FILE *srcfile_relative_open(const char *fname, char **fullnamep)

  {

  	FILE *f;

  	char *fullname;

  	if (streq(fname, "-")) {
  		f = stdin;
  		fullname = xstrdup("<stdin>");

  	} else {

  		fullname = fopen_any_on_path(fname, &f);

  		if (!f)
  			die("Couldn't open \"%s\": %s
  ", fname,
  			    strerror(errno));

  	}

  	if (depfile)
  		fprintf(depfile, " %s", fullname);

  	if (fullnamep)
  		*fullnamep = fullname;
  	else

  		free(fullname);

  	return f;

  }

  void srcfile_push(const char *fname)
  {
  	struct srcfile_state *srcfile;
  
  	if (srcfile_depth++ >= MAX_SRCFILE_DEPTH)
  		die("Includes nested too deeply");
  
  	srcfile = xmalloc(sizeof(*srcfile));
  
  	srcfile->f = srcfile_relative_open(fname, &srcfile->name);

  	srcfile->dir = get_dirname(srcfile->name);

  	srcfile->prev = current_srcfile;
  
  	srcfile->lineno = 1;
  	srcfile->colno = 1;
  
  	current_srcfile = srcfile;
  }

  bool srcfile_pop(void)

  {

  	struct srcfile_state *srcfile = current_srcfile;

  	assert(srcfile);

  	current_srcfile = srcfile->prev;

  	if (fclose(srcfile->f))
  		die("Error closing \"%s\": %s
  ", srcfile->name,
  		    strerror(errno));

  	/* FIXME: We allow the srcfile_state structure to leak,
  	 * because it could still be referenced from a location
  	 * variable being carried through the parser somewhere.  To
  	 * fix this we could either allocate all the files from a
  	 * table, or use a pool allocator. */

  	return current_srcfile ? true : false;

  }

  void srcfile_add_search_path(const char *dirname)
  {
  	struct search_path *node;
  
  	/* Create the node */
  	node = xmalloc(sizeof(*node));
  	node->next = NULL;
  	node->dirname = xstrdup(dirname);
  
  	/* Add to the end of our list */
  	if (search_path_tail)
  		*search_path_tail = node;
  	else
  		search_path_head = node;
  	search_path_tail = &node->next;
  }

  /*
   * The empty source position.
   */

  struct srcpos srcpos_empty = {
  	.first_line = 0,
  	.first_column = 0,
  	.last_line = 0,
  	.last_column = 0,
  	.file = NULL,
  };

  #define TAB_SIZE      8

  void srcpos_update(struct srcpos *pos, const char *text, int len)
  {
  	int i;
  
  	pos->file = current_srcfile;
  
  	pos->first_line = current_srcfile->lineno;
  	pos->first_column = current_srcfile->colno;
  
  	for (i = 0; i < len; i++)
  		if (text[i] == '
  ') {
  			current_srcfile->lineno++;
  			current_srcfile->colno = 1;
  		} else if (text[i] == '\t') {
  			current_srcfile->colno =
  				ALIGN(current_srcfile->colno, TAB_SIZE);
  		} else {
  			current_srcfile->colno++;
  		}
  
  	pos->last_line = current_srcfile->lineno;
  	pos->last_column = current_srcfile->colno;
  }

  struct srcpos *
  srcpos_copy(struct srcpos *pos)
  {
  	struct srcpos *pos_new;

  	pos_new = xmalloc(sizeof(struct srcpos));
  	memcpy(pos_new, pos, sizeof(struct srcpos));
  
  	return pos_new;
  }

  char *
  srcpos_string(struct srcpos *pos)
  {
  	const char *fname = "<no-file>";
  	char *pos_str;

  	if (pos->file && pos->file->name)

  		fname = pos->file->name;
  
  
  	if (pos->first_line != pos->last_line)

  		xasprintf(&pos_str, "%s:%d.%d-%d.%d", fname,
  			  pos->first_line, pos->first_column,
  			  pos->last_line, pos->last_column);

  	else if (pos->first_column != pos->last_column)

  		xasprintf(&pos_str, "%s:%d.%d-%d", fname,
  			  pos->first_line, pos->first_column,
  			  pos->last_column);

  	else

  		xasprintf(&pos_str, "%s:%d.%d", fname,
  			  pos->first_line, pos->first_column);

  
  	return pos_str;
  }

  void srcpos_verror(struct srcpos *pos, const char *prefix,
  		   const char *fmt, va_list va)

  {

  	char *srcstr;

  	srcstr = srcpos_string(pos);

  	fprintf(stderr, "%s: %s ", prefix, srcstr);
  	vfprintf(stderr, fmt, va);
  	fprintf(stderr, "
  ");

  	free(srcstr);

  }

  void srcpos_error(struct srcpos *pos, const char *prefix,
  		  const char *fmt, ...)

  {

  	va_list va;

  	va_start(va, fmt);
  	srcpos_verror(pos, prefix, fmt, va);

  	va_end(va);

  }

  
  void srcpos_set_line(char *f, int l)
  {
  	current_srcfile->name = f;
  	current_srcfile->lineno = l;
  }