1/*	$NetBSD: srcpos.c,v 1.4 2019/12/22 12:38:24 skrll Exp $	*/
2
3// SPDX-License-Identifier: GPL-2.0-or-later
4/*
5 * Copyright 2007 Jon Loeliger, Freescale Semiconductor, Inc.
6 */
7
8#define _GNU_SOURCE
9
10#include <stdio.h>
11
12#include "dtc.h"
13#include "srcpos.h"
14
15/* A node in our list of directories to search for source/include files */
16struct search_path {
17	struct search_path *next;	/* next node in list, NULL for end */
18	const char *dirname;		/* name of directory to search */
19};
20
21/* This is the list of directories that we search for source files */
22static struct search_path *search_path_head, **search_path_tail;
23
24/* Detect infinite include recursion. */
25#define MAX_SRCFILE_DEPTH     (100)
26static int srcfile_depth; /* = 0 */
27
28static char *get_dirname(const char *path)
29{
30	const char *slash = strrchr(path, '/');
31
32	if (slash) {
33		int len = slash - path;
34		char *dir = xmalloc(len + 1);
35
36		memcpy(dir, path, len);
37		dir[len] = '\0';
38		return dir;
39	}
40	return NULL;
41}
42
43FILE *depfile; /* = NULL */
44struct srcfile_state *current_srcfile; /* = NULL */
45static char *initial_path; /* = NULL */
46static int initial_pathlen; /* = 0 */
47static bool initial_cpp = true;
48
49static void set_initial_path(char *fname)
50{
51	int i, len = strlen(fname);
52
53	xasprintf(&initial_path, "%s", fname);
54	initial_pathlen = 0;
55	for (i = 0; i != len; i++)
56		if (initial_path[i] == '/')
57			initial_pathlen++;
58}
59
60static char *shorten_to_initial_path(char *fname)
61{
62	char *p1, *p2, *prevslash1 = NULL;
63	int slashes = 0;
64
65	for (p1 = fname, p2 = initial_path; *p1 && *p2; p1++, p2++) {
66		if (*p1 != *p2)
67			break;
68		if (*p1 == '/') {
69			prevslash1 = p1;
70			slashes++;
71		}
72	}
73	p1 = prevslash1 + 1;
74	if (prevslash1) {
75		int diff = initial_pathlen - slashes, i, j;
76		int restlen = strlen(fname) - (p1 - fname);
77		char *res;
78
79		res = xmalloc((3 * diff) + restlen + 1);
80		for (i = 0, j = 0; i != diff; i++) {
81			res[j++] = '.';
82			res[j++] = '.';
83			res[j++] = '/';
84		}
85		strcpy(res + j, p1);
86		return res;
87	}
88	return NULL;
89}
90
91/**
92 * Try to open a file in a given directory.
93 *
94 * If the filename is an absolute path, then dirname is ignored. If it is a
95 * relative path, then we look in that directory for the file.
96 *
97 * @param dirname	Directory to look in, or NULL for none
98 * @param fname		Filename to look for
99 * @param fp		Set to NULL if file did not open
100 * @return allocated filename on success (caller must free), NULL on failure
101 */
102static char *try_open(const char *dirname, const char *fname, FILE **fp)
103{
104	char *fullname;
105
106	if (!dirname || fname[0] == '/')
107		fullname = xstrdup(fname);
108	else
109		fullname = join_path(dirname, fname);
110
111	*fp = fopen(fullname, "rb");
112	if (!*fp) {
113		free(fullname);
114		fullname = NULL;
115	}
116
117	return fullname;
118}
119
120/**
121 * Open a file for read access
122 *
123 * If it is a relative filename, we search the full search path for it.
124 *
125 * @param fname	Filename to open
126 * @param fp	Returns pointer to opened FILE, or NULL on failure
127 * @return pointer to allocated filename, which caller must free
128 */
129static char *fopen_any_on_path(const char *fname, FILE **fp)
130{
131	const char *cur_dir = NULL;
132	struct search_path *node;
133	char *fullname;
134
135	/* Try current directory first */
136	assert(fp);
137	if (current_srcfile)
138		cur_dir = current_srcfile->dir;
139	fullname = try_open(cur_dir, fname, fp);
140
141	/* Failing that, try each search path in turn */
142	for (node = search_path_head; !*fp && node; node = node->next)
143		fullname = try_open(node->dirname, fname, fp);
144
145	return fullname;
146}
147
148FILE *srcfile_relative_open(const char *fname, char **fullnamep)
149{
150	FILE *f;
151	char *fullname;
152
153	if (streq(fname, "-")) {
154		f = stdin;
155		fullname = xstrdup("<stdin>");
156	} else {
157		fullname = fopen_any_on_path(fname, &f);
158		if (!f)
159			die("Couldn't open \"%s\": %s\n", fname,
160			    strerror(errno));
161	}
162
163	if (depfile)
164		fprintf(depfile, " %s", fullname);
165
166	if (fullnamep)
167		*fullnamep = fullname;
168	else
169		free(fullname);
170
171	return f;
172}
173
174void srcfile_push(const char *fname)
175{
176	struct srcfile_state *srcfile;
177
178	if (srcfile_depth++ >= MAX_SRCFILE_DEPTH)
179		die("Includes nested too deeply");
180
181	srcfile = xmalloc(sizeof(*srcfile));
182
183	srcfile->f = srcfile_relative_open(fname, &srcfile->name);
184	srcfile->dir = get_dirname(srcfile->name);
185	srcfile->prev = current_srcfile;
186
187	srcfile->lineno = 1;
188	srcfile->colno = 1;
189
190	current_srcfile = srcfile;
191
192	if (srcfile_depth == 1)
193		set_initial_path(srcfile->name);
194}
195
196bool srcfile_pop(void)
197{
198	struct srcfile_state *srcfile = current_srcfile;
199
200	assert(srcfile);
201
202	current_srcfile = srcfile->prev;
203
204	if (fclose(srcfile->f))
205		die("Error closing \"%s\": %s\n", srcfile->name,
206		    strerror(errno));
207
208	/* FIXME: We allow the srcfile_state structure to leak,
209	 * because it could still be referenced from a location
210	 * variable being carried through the parser somewhere.  To
211	 * fix this we could either allocate all the files from a
212	 * table, or use a pool allocator. */
213
214	return current_srcfile ? true : false;
215}
216
217void srcfile_add_search_path(const char *dirname)
218{
219	struct search_path *node;
220
221	/* Create the node */
222	node = xmalloc(sizeof(*node));
223	node->next = NULL;
224	node->dirname = xstrdup(dirname);
225
226	/* Add to the end of our list */
227	if (search_path_tail)
228		*search_path_tail = node;
229	else
230		search_path_head = node;
231	search_path_tail = &node->next;
232}
233
234void srcpos_update(struct srcpos *pos, const char *text, int len)
235{
236	int i;
237
238	pos->file = current_srcfile;
239
240	pos->first_line = current_srcfile->lineno;
241	pos->first_column = current_srcfile->colno;
242
243	for (i = 0; i < len; i++)
244		if (text[i] == '\n') {
245			current_srcfile->lineno++;
246			current_srcfile->colno = 1;
247		} else {
248			current_srcfile->colno++;
249		}
250
251	pos->last_line = current_srcfile->lineno;
252	pos->last_column = current_srcfile->colno;
253}
254
255struct srcpos *
256srcpos_copy(struct srcpos *pos)
257{
258	struct srcpos *pos_new;
259	struct srcfile_state *srcfile_state;
260
261	if (!pos)
262		return NULL;
263
264	pos_new = xmalloc(sizeof(struct srcpos));
265	assert(pos->next == NULL);
266	memcpy(pos_new, pos, sizeof(struct srcpos));
267
268	/* allocate without free */
269	srcfile_state = xmalloc(sizeof(struct srcfile_state));
270	memcpy(srcfile_state, pos->file, sizeof(struct srcfile_state));
271	pos_new->file = srcfile_state;
272
273	return pos_new;
274}
275
276struct srcpos *srcpos_extend(struct srcpos *pos, struct srcpos *newtail)
277{
278	struct srcpos *p;
279
280	if (!pos)
281		return newtail;
282
283	for (p = pos; p->next != NULL; p = p->next);
284	p->next = newtail;
285	return pos;
286}
287
288char *
289srcpos_string(struct srcpos *pos)
290{
291	const char *fname = "<no-file>";
292	char *pos_str;
293
294	if (pos->file && pos->file->name)
295		fname = pos->file->name;
296
297
298	if (pos->first_line != pos->last_line)
299		xasprintf(&pos_str, "%s:%d.%d-%d.%d", fname,
300			  pos->first_line, pos->first_column,
301			  pos->last_line, pos->last_column);
302	else if (pos->first_column != pos->last_column)
303		xasprintf(&pos_str, "%s:%d.%d-%d", fname,
304			  pos->first_line, pos->first_column,
305			  pos->last_column);
306	else
307		xasprintf(&pos_str, "%s:%d.%d", fname,
308			  pos->first_line, pos->first_column);
309
310	return pos_str;
311}
312
313static char *
314srcpos_string_comment(struct srcpos *pos, bool first_line, int level)
315{
316	char *pos_str, *fname, *first, *rest;
317	bool fresh_fname = false;
318
319	if (!pos) {
320		if (level > 1) {
321			xasprintf(&pos_str, "<no-file>:<no-line>");
322			return pos_str;
323		} else {
324			return NULL;
325		}
326	}
327
328	if (!pos->file)
329		fname = "<no-file>";
330	else if (!pos->file->name)
331		fname = "<no-filename>";
332	else if (level > 1)
333		fname = pos->file->name;
334	else {
335		fname = shorten_to_initial_path(pos->file->name);
336		if (fname)
337			fresh_fname = true;
338		else
339			fname = pos->file->name;
340	}
341
342	if (level > 1)
343		xasprintf(&first, "%s:%d:%d-%d:%d", fname,
344			  pos->first_line, pos->first_column,
345			  pos->last_line, pos->last_column);
346	else
347		xasprintf(&first, "%s:%d", fname,
348			  first_line ? pos->first_line : pos->last_line);
349
350	if (fresh_fname)
351		free(fname);
352
353	if (pos->next != NULL) {
354		rest = srcpos_string_comment(pos->next, first_line, level);
355		xasprintf(&pos_str, "%s, %s", first, rest);
356		free(first);
357		free(rest);
358	} else {
359		pos_str = first;
360	}
361
362	return pos_str;
363}
364
365char *srcpos_string_first(struct srcpos *pos, int level)
366{
367	return srcpos_string_comment(pos, true, level);
368}
369
370char *srcpos_string_last(struct srcpos *pos, int level)
371{
372	return srcpos_string_comment(pos, false, level);
373}
374
375void srcpos_verror(struct srcpos *pos, const char *prefix,
376		   const char *fmt, va_list va)
377{
378	char *srcstr;
379
380	srcstr = srcpos_string(pos);
381
382	fprintf(stderr, "%s: %s ", prefix, srcstr);
383	vfprintf(stderr, fmt, va);
384	fprintf(stderr, "\n");
385
386	free(srcstr);
387}
388
389void srcpos_error(struct srcpos *pos, const char *prefix,
390		  const char *fmt, ...)
391{
392	va_list va;
393
394	va_start(va, fmt);
395	srcpos_verror(pos, prefix, fmt, va);
396	va_end(va);
397}
398
399void srcpos_set_line(char *f, int l)
400{
401	current_srcfile->name = f;
402	current_srcfile->lineno = l;
403
404	if (initial_cpp) {
405		initial_cpp = false;
406		set_initial_path(f);
407	}
408}
409