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io.c revision 1.234 
      1 /*	$NetBSD: io.c,v 1.234 2023/12/03 21:40:44 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 1.234 2023/12/03 21:40:44 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(&inp);
     66 
     67 	for (;;) {
     68 		int ch = getc(input);
     69 		if (ch == EOF) {
     70 			if (indent_enabled == indent_on) {
     71 				buf_add_char(&inp, ' ');
     72 				buf_add_char(&inp, '\n');
     73 			}
     74 			had_eof = true;
     75 			break;
     76 		}
     77 
     78 		if (ch != '\0')
     79 			buf_add_char(&inp, (char)ch);
     80 		if (ch == '\n')
     81 			break;
     82 	}
     83 	buf_terminate(&inp);
     84 	inp_p = inp.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, inp.s, inp.len);
     93 	inp_read_next_line();
     94 }
     95 
     96 void
     97 inp_skip(void)
     98 {
     99 	inp_p++;
    100 	if ((size_t)(inp_p - inp.s) >= inp.len)
    101 		inp_read_line();
    102 }
    103 
    104 char
    105 inp_next(void)
    106 {
    107 	char ch = inp_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