// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * Copyright 2007 Jon Loeliger, Freescale Semiconductor, Inc.

 */

#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;

/* Detect infinite include recursion. */

#define MAX_SRCFILE_DEPTH     (100)

static int srcfile_depth; /* = 0 */

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 */

static char *initial_path; /* = NULL */

static int initial_pathlen; /* = 0 */

static bool initial_cpp = true;

static void set_initial_path(char *fname)

{

	int i, len = strlen(fname);

	xasprintf(&initial_path, "%s", fname);

	initial_pathlen = 0;

	for (i = 0; i != len; i++)

		if (initial_path[i] == '/')

			initial_pathlen++;

}

static char *shorten_to_initial_path(char *fname)

{

	char *p1, *p2, *prevslash1 = NULL;

	int slashes = 0;

	for (p1 = fname, p2 = initial_path; *p1 && *p2; p1++, p2++) {

		if (*p1 != *p2)

			break;

		if (*p1 == '/') {

			prevslash1 = p1;

			slashes++;

		}

	}

	p1 = prevslash1 + 1;

	if (prevslash1) {

		int diff = initial_pathlen - slashes, i, j;

		int restlen = strlen(fname) - (p1 - fname);

		char *res;

		res = xmalloc((3 * diff) + restlen + 1);

		for (i = 0, j = 0; i != diff; i++) {

			res[j++] = '.';

			res[j++] = '.';

			res[j++] = '/';

		}

		strcpy(res + j, p1);

		return res;

	}

	return NULL;

}

/**

 * 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;

	if (srcfile_depth == 1)

		set_initial_path(srcfile->name);

}

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;

}

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;

	struct srcfile_state *srcfile_state;

	if (!pos)

		return NULL;

	pos_new = xmalloc(sizeof(struct srcpos));

	assert(pos->next == NULL);

	memcpy(pos_new, pos, sizeof(struct srcpos));

	/* allocate without free */

	srcfile_state = xmalloc(sizeof(struct srcfile_state));

	memcpy(srcfile_state, pos->file, sizeof(struct srcfile_state));

	pos_new->file = srcfile_state;

	return pos_new;

}

struct srcpos *srcpos_extend(struct srcpos *pos, struct srcpos *newtail)

{

	struct srcpos *p;

	if (!pos)

		return newtail;

	for (p = pos; p->next != NULL; p = p->next);

	p->next = newtail;

	return pos;

}

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;

}

static char *

srcpos_string_comment(struct srcpos *pos, bool first_line, int level)

{

	char *pos_str, *fname, *first, *rest;

	bool fresh_fname = false;

	if (!pos) {

		if (level > 1) {

			xasprintf(&pos_str, "<no-file>:<no-line>");

			return pos_str;

		} else {

			return NULL;

		}

	}

	if (!pos->file)

		fname = "<no-file>";

	else if (!pos->file->name)

		fname = "<no-filename>";

	else if (level > 1)

		fname = pos->file->name;

	else {

		fname = shorten_to_initial_path(pos->file->name);

		if (fname)

			fresh_fname = true;

		else

			fname = pos->file->name;

	}

	if (level > 1)

		xasprintf(&first, "%s:%d:%d-%d:%d", fname,

			  pos->first_line, pos->first_column,

			  pos->last_line, pos->last_column);

	else

		xasprintf(&first, "%s:%d", fname,

			  first_line ? pos->first_line : pos->last_line);

	if (fresh_fname)

		free(fname);

	if (pos->next != NULL) {

		rest = srcpos_string_comment(pos->next, first_line, level);

		xasprintf(&pos_str, "%s, %s", first, rest);

		free(first);

		free(rest);

	} else {

		pos_str = first;

	}

	return pos_str;

}

char *srcpos_string_first(struct srcpos *pos, int level)

{

	return srcpos_string_comment(pos, true, level);

}

char *srcpos_string_last(struct srcpos *pos, int level)

{

	return srcpos_string_comment(pos, false, level);

}

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;

	if (initial_cpp) {

		initial_cpp = false;

		set_initial_path(f);

	}

}