xref: /netbsd-src/usr.bin/indent/io.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
1 /*	$NetBSD: io.c,v 1.235 2023/12/03 21:44:42 rillig Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-4-Clause
5  *
6  * Copyright (c) 1985 Sun Microsystems, Inc.
7  * Copyright (c) 1980, 1993
8  *	The Regents of the University of California.  All rights reserved.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #include <sys/cdefs.h>
41 __RCSID("$NetBSD: io.c,v 1.235 2023/12/03 21:44:42 rillig Exp $");
42 
43 #include <stdio.h>
44 
45 #include "indent.h"
46 
47 struct input_state in = {
48 	.token_end_line = 1,
49 };
50 
51 struct output_state out;
52 enum indent_enabled indent_enabled;
53 static int out_ind;		/* width of the line that is being written */
54 static unsigned newlines = 2;	/* the total of written and buffered newlines;
55 				 * 0 in the middle of a line, 1 after a single
56 				 * finished line, anything > 1 are trailing
57 				 * blank lines */
58 static unsigned buffered_newlines;	/* not yet written */
59 static int paren_indent;	/* total indentation when parenthesized */
60 
61 
62 static void
63 inp_read_next_line(void)
64 {
65 	buf_clear(&in.line);
66 
67 	for (;;) {
68 		int ch = getc(in.f);
69 		if (ch == EOF) {
70 			if (indent_enabled == indent_on) {
71 				buf_add_char(&in.line, ' ');
72 				buf_add_char(&in.line, '\n');
73 			}
74 			had_eof = true;
75 			break;
76 		}
77 
78 		if (ch != '\0')
79 			buf_add_char(&in.line, (char)ch);
80 		if (ch == '\n')
81 			break;
82 	}
83 	buf_terminate(&in.line);
84 	in.p = in.line.s;
85 }
86 
87 void
88 inp_read_line(void)
89 {
90 	if (indent_enabled == indent_on)
91 		buf_clear(&out.indent_off_text);
92 	buf_add_chars(&out.indent_off_text, in.line.s, in.line.len);
93 	inp_read_next_line();
94 }
95 
96 void
97 inp_skip(void)
98 {
99 	in.p++;
100 	if ((size_t)(in.p - in.line.s) >= in.line.len)
101 		inp_read_line();
102 }
103 
104 char
105 inp_next(void)
106 {
107 	char ch = in.p[0];
108 	inp_skip();
109 	return ch;
110 }
111 
112 
113 static void
114 add_buffered_newline(void)
115 {
116 	buffered_newlines++;
117 	newlines++;
118 	out_ind = 0;
119 }
120 
121 static void
122 write_buffered_newlines(void)
123 {
124 	for (; buffered_newlines > 0; buffered_newlines--) {
125 		fputc('\n', output);
126 		debug_println("write_newline");
127 	}
128 }
129 
130 static void
131 write_range(const char *s, size_t len)
132 {
133 	write_buffered_newlines();
134 	fwrite(s, 1, len, output);
135 	debug_printf("write_range ");
136 	debug_vis_range(s, len);
137 	debug_println("");
138 	for (size_t i = 0; i < len; i++)
139 		newlines = s[i] == '\n' ? newlines + 1 : 0;
140 	out_ind = ind_add(out_ind, s, len);
141 }
142 
143 static void
144 write_indent(int new_ind)
145 {
146 	write_buffered_newlines();
147 
148 	int ind = out_ind;
149 
150 	if (opt.use_tabs) {
151 		int n = new_ind / opt.tabsize - ind / opt.tabsize;
152 		if (n > 0) {
153 			ind = ind - ind % opt.tabsize + n * opt.tabsize;
154 			while (n-- > 0)
155 				fputc('\t', output);
156 			newlines = 0;
157 		}
158 	}
159 
160 	for (; ind < new_ind; ind++) {
161 		fputc(' ', output);
162 		newlines = 0;
163 	}
164 
165 	debug_println("write_indent %d", ind);
166 	out_ind = ind;
167 }
168 
169 static bool
170 want_blank_line(void)
171 {
172 	debug_println("%s: %s -> %s", __func__,
173 	    line_kind_name[out.prev_line_kind], line_kind_name[out.line_kind]);
174 
175 	if (((ps.blank_line_after_decl && ps.declaration == decl_no)
176 	    || ps.badp == badp_yes)
177 	    && (lab.len > 0 || code.len > 0)) {
178 		ps.blank_line_after_decl = false;
179 		ps.badp = badp_none;
180 		return true;
181 	}
182 
183 	if (opt.blank_line_around_conditional_compilation) {
184 		if (out.prev_line_kind != lk_pre_if
185 		    && out.line_kind == lk_pre_if)
186 			return true;
187 		if (out.prev_line_kind == lk_pre_endif
188 		    && out.line_kind != lk_pre_endif)
189 			return true;
190 	}
191 	if (opt.blank_line_after_proc && out.prev_line_kind == lk_func_end
192 	    && out.line_kind != lk_pre_endif && out.line_kind != lk_pre_other)
193 		return true;
194 	if (opt.blank_line_before_block_comment
195 	    && out.line_kind == lk_block_comment)
196 		return true;
197 	return false;
198 }
199 
200 static bool
201 is_blank_line_optional(void)
202 {
203 	if (out.prev_line_kind == lk_stmt_head)
204 		return newlines >= 1;
205 	if (ps.psyms.len >= 3)
206 		return newlines >= 2;
207 	return newlines >= 3;
208 }
209 
210 static int
211 compute_case_label_indent(void)
212 {
213 	size_t i = ps.psyms.len - 1;
214 	while (i > 0 && ps.psyms.sym[i] != psym_switch_expr)
215 		i--;
216 	float case_ind = (float)ps.psyms.ind_level[i] + opt.case_indent;
217 	// TODO: case_ind may become negative here.
218 	return (int)(case_ind * (float)opt.indent_size);
219 }
220 
221 int
222 compute_label_indent(void)
223 {
224 	if (out.line_kind == lk_case_or_default)
225 		return compute_case_label_indent();
226 	if (lab.s[0] == '#')
227 		return 0;
228 	// TODO: the indentation may become negative here.
229 	return opt.indent_size * (ps.ind_level - 2);
230 }
231 
232 static void
233 output_line_label(void)
234 {
235 	write_indent(compute_label_indent());
236 	write_range(lab.s, lab.len);
237 }
238 
239 static int
240 compute_lined_up_code_indent(int base_ind)
241 {
242 	int ind = paren_indent;
243 	int overflow = ind_add(ind, code.s, code.len) - opt.max_line_length;
244 	if (overflow >= 0
245 	    && ind_add(base_ind, code.s, code.len) < opt.max_line_length) {
246 		ind -= 2 + overflow;
247 		if (ind < base_ind)
248 			ind = base_ind;
249 	}
250 
251 	if (ps.extra_expr_indent != eei_no
252 	    && ind == base_ind + opt.indent_size)
253 		ind += opt.continuation_indent;
254 	return ind;
255 }
256 
257 int
258 compute_code_indent(void)
259 {
260 	int base_ind = ps.ind_level * opt.indent_size;
261 
262 	if (ps.ind_paren_level == 0) {
263 		if (ps.line_is_stmt_cont)
264 			return base_ind + opt.continuation_indent;
265 		return base_ind;
266 	}
267 
268 	if (opt.lineup_to_parens) {
269 		if (opt.lineup_to_parens_always)
270 			return paren_indent;
271 		return compute_lined_up_code_indent(base_ind);
272 	}
273 
274 	int rel_ind = opt.continuation_indent * ps.ind_paren_level;
275 	if (ps.extra_expr_indent != eei_no && rel_ind == opt.indent_size)
276 		rel_ind += opt.continuation_indent;
277 	return base_ind + rel_ind;
278 }
279 
280 static void
281 output_line_code(void)
282 {
283 	int target_ind = compute_code_indent();
284 	for (size_t i = 0; i < ps.paren.len; i++) {
285 		int paren_ind = ps.paren.item[i].indent;
286 		if (paren_ind >= 0) {
287 			ps.paren.item[i].indent =
288 			    -1 - (paren_ind + target_ind);
289 			debug_println(
290 			    "setting paren_indents[%zu] from %d to %d "
291 			    "for column %d",
292 			    i, paren_ind,
293 			    ps.paren.item[i].indent, target_ind + 1);
294 		}
295 	}
296 
297 	if (lab.len > 0 && target_ind <= out_ind)
298 		write_range(" ", 1);
299 	write_indent(target_ind);
300 	write_range(code.s, code.len);
301 }
302 
303 static void
304 output_comment(void)
305 {
306 	int target_ind = ps.comment_ind;
307 	const char *p;
308 
309 	if (ps.comment_cont)
310 		target_ind += ps.comment_shift;
311 	ps.comment_cont = true;
312 
313 	/* consider the original indentation in case this is a box comment */
314 	for (p = com.s; *p == '\t'; p++)
315 		target_ind += opt.tabsize;
316 
317 	for (; target_ind < 0; p++) {
318 		if (*p == ' ')
319 			target_ind++;
320 		else if (*p == '\t')
321 			target_ind = next_tab(target_ind);
322 		else {
323 			target_ind = 0;
324 			break;
325 		}
326 	}
327 
328 	if (out_ind > target_ind)
329 		add_buffered_newline();
330 
331 	while (com.s + com.len > p && ch_isspace(com.s[com.len - 1]))
332 		com.len--;
333 	buf_terminate(&com);
334 
335 	write_indent(target_ind);
336 	write_range(p, com.len - (size_t)(p - com.s));
337 }
338 
339 /*
340  * Write a line of formatted source to the output file. The line consists of
341  * the label, the code and the comment.
342  */
343 static void
344 output_indented_line(void)
345 {
346 	if (lab.len == 0 && code.len == 0 && com.len == 0)
347 		out.line_kind = lk_blank;
348 
349 	if (want_blank_line() && newlines < 2 && out.line_kind != lk_blank)
350 		add_buffered_newline();
351 
352 	/* This kludge aligns function definitions correctly. */
353 	if (ps.ind_level == 0)
354 		ps.line_is_stmt_cont = false;
355 
356 	if (opt.blank_line_after_decl && ps.declaration == decl_end
357 	    && ps.psyms.len > 2) {
358 		ps.declaration = decl_no;
359 		ps.blank_line_after_decl = true;
360 	}
361 
362 	if (opt.swallow_optional_blank_lines
363 	    && out.line_kind == lk_blank
364 	    && is_blank_line_optional())
365 		return;
366 
367 	if (lab.len > 0)
368 		output_line_label();
369 	if (code.len > 0)
370 		output_line_code();
371 	if (com.len > 0)
372 		output_comment();
373 	add_buffered_newline();
374 	if (out.line_kind != lk_blank)
375 		write_buffered_newlines();
376 
377 	out.prev_line_kind = out.line_kind;
378 }
379 
380 static bool
381 is_stmt_cont(void)
382 {
383 	if (ps.psyms.len >= 2
384 	    && ps.psyms.sym[ps.psyms.len - 2] == psym_lbrace_enum
385 	    && ps.prev_lsym == lsym_comma
386 	    && ps.paren.len == 0)
387 		return false;
388 	return ps.in_stmt_or_decl
389 	    && (!ps.in_decl || ps.in_init)
390 	    && ps.init_level == 0;
391 }
392 
393 static void
394 prepare_next_line(void)
395 {
396 	ps.line_has_decl = ps.in_decl;
397 	ps.line_has_func_def = false;
398 	ps.line_is_stmt_cont = is_stmt_cont();
399 	ps.decl_indent_done = false;
400 	if (ps.extra_expr_indent == eei_last)
401 		ps.extra_expr_indent = eei_no;
402 	if (!(ps.psyms.sym[ps.psyms.len - 1] == psym_if_expr_stmt_else
403 		&& ps.paren.len > 0))
404 		ps.ind_level = ps.ind_level_follow;
405 	ps.ind_paren_level = (int)ps.paren.len;
406 	ps.want_blank = false;
407 	if ((ps.badp == badp_seen_lbrace || ps.badp == badp_seen_decl)
408 	    && !ps.in_decl)
409 		ps.badp = badp_yes;
410 
411 	if (ps.paren.len > 0) {
412 		/* TODO: explain what negative indentation means */
413 		paren_indent = -1 - ps.paren.item[ps.paren.len - 1].indent;
414 		debug_println("paren_indent is now %d", paren_indent);
415 	}
416 
417 	out.line_kind = lk_other;
418 }
419 
420 void
421 output_line(void)
422 {
423 	debug_blank_line();
424 	debug_printf("%s", __func__);
425 	debug_buffers();
426 
427 	if (indent_enabled == indent_on)
428 		output_indented_line();
429 	else if (indent_enabled == indent_last_off_line) {
430 		indent_enabled = indent_on;
431 		write_range(out.indent_off_text.s, out.indent_off_text.len);
432 		buf_clear(&out.indent_off_text);
433 	}
434 
435 	buf_clear(&lab);
436 	buf_clear(&code);
437 	buf_clear(&com);
438 
439 	prepare_next_line();
440 }
441 
442 void
443 finish_output(void)
444 {
445 	output_line();
446 	if (indent_enabled != indent_on) {
447 		indent_enabled = indent_last_off_line;
448 		output_line();
449 	}
450 	fflush(output);
451 }
452