/*
 * 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\n", 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\n", 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,
};

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] == '\n') {
                        current_srcfile->lineno++;
                        current_srcfile->colno = 1;
                } 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, "\n");

        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;
}