numfmt: prefer signed types
[coreutils.git] / src / fmt.c
blobad7a9ce56a00d13bc87e7810b5c68cdf35dd973d
1 /* GNU fmt -- simple text formatter.
2 Copyright (C) 1994-2023 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17 /* Written by Ross Paterson <rap@doc.ic.ac.uk>. */
19 #include <config.h>
20 #include <stdio.h>
21 #include <sys/types.h>
22 #include <getopt.h>
24 /* Redefine. Otherwise, systems (Unicos for one) with headers that define
25 it to be a type get syntax errors for the variable declaration below. */
26 #define word unused_word_type
28 #include "c-ctype.h"
29 #include "system.h"
30 #include "fadvise.h"
31 #include "xdectoint.h"
33 /* The official name of this program (e.g., no 'g' prefix). */
34 #define PROGRAM_NAME "fmt"
36 #define AUTHORS proper_name ("Ross Paterson")
38 /* The following parameters represent the program's idea of what is
39 "best". Adjust to taste, subject to the caveats given. */
41 /* Default longest permitted line length (max_width). */
42 #define WIDTH 75
44 /* Prefer lines to be LEEWAY % shorter than the maximum width, giving
45 room for optimization. */
46 #define LEEWAY 7
48 /* The default secondary indent of tagged paragraph used for unindented
49 one-line paragraphs not preceded by any multi-line paragraphs. */
50 #define DEF_INDENT 3
52 /* Costs and bonuses are expressed as the equivalent departure from the
53 optimal line length, multiplied by 10. e.g. assigning something a
54 cost of 50 means that it is as bad as a line 5 characters too short
55 or too long. The definition of SHORT_COST(n) should not be changed.
56 However, EQUIV(n) may need tuning. */
58 /* FIXME: "fmt" misbehaves given large inputs or options. One
59 possible workaround for part of the problem is to change COST to be
60 a floating-point type. There are other problems besides COST,
61 though; see MAXWORDS below. */
63 typedef long int COST;
65 #define MAXCOST TYPE_MAXIMUM (COST)
67 #define SQR(n) ((n) * (n))
68 #define EQUIV(n) SQR ((COST) (n))
70 /* Cost of a filled line n chars longer or shorter than goal_width. */
71 #define SHORT_COST(n) EQUIV ((n) * 10)
73 /* Cost of the difference between adjacent filled lines. */
74 #define RAGGED_COST(n) (SHORT_COST (n) / 2)
76 /* Basic cost per line. */
77 #define LINE_COST EQUIV (70)
79 /* Cost of breaking a line after the first word of a sentence, where
80 the length of the word is N. */
81 #define WIDOW_COST(n) (EQUIV (200) / ((n) + 2))
83 /* Cost of breaking a line before the last word of a sentence, where
84 the length of the word is N. */
85 #define ORPHAN_COST(n) (EQUIV (150) / ((n) + 2))
87 /* Bonus for breaking a line at the end of a sentence. */
88 #define SENTENCE_BONUS EQUIV (50)
90 /* Cost of breaking a line after a period not marking end of a sentence.
91 With the definition of sentence we are using (borrowed from emacs, see
92 get_line()) such a break would then look like a sentence break. Hence
93 we assign a very high cost -- it should be avoided unless things are
94 really bad. */
95 #define NOBREAK_COST EQUIV (600)
97 /* Bonus for breaking a line before open parenthesis. */
98 #define PAREN_BONUS EQUIV (40)
100 /* Bonus for breaking a line after other punctuation. */
101 #define PUNCT_BONUS EQUIV(40)
103 /* Credit for breaking a long paragraph one line later. */
104 #define LINE_CREDIT EQUIV(3)
106 /* Size of paragraph buffer, in words and characters. Longer paragraphs
107 are handled neatly (cf. flush_paragraph()), so long as these values
108 are considerably greater than required by the width. These values
109 cannot be extended indefinitely: doing so would run into size limits
110 and/or cause more overflows in cost calculations. FIXME: Remove these
111 arbitrary limits. */
113 #define MAXWORDS 1000
114 #define MAXCHARS 5000
116 /* Extra ctype(3)-style macros. */
118 #define isopen(c) (strchr ("(['`\"", c) != nullptr)
119 #define isclose(c) (strchr (")]'\"", c) != nullptr)
120 #define isperiod(c) (strchr (".?!", c) != nullptr)
122 /* Size of a tab stop, for expansion on input and re-introduction on
123 output. */
124 #define TABWIDTH 8
126 /* Word descriptor structure. */
128 typedef struct Word WORD;
130 struct Word
133 /* Static attributes determined during input. */
135 char const *text; /* the text of the word */
136 int length; /* length of this word */
137 int space; /* the size of the following space */
138 unsigned int paren:1; /* starts with open paren */
139 unsigned int period:1; /* ends in [.?!])* */
140 unsigned int punct:1; /* ends in punctuation */
141 unsigned int final:1; /* end of sentence */
143 /* The remaining fields are computed during the optimization. */
145 int line_length; /* length of the best line starting here */
146 COST best_cost; /* cost of best paragraph starting here */
147 WORD *next_break; /* break which achieves best_cost */
150 /* Forward declarations. */
152 static void set_prefix (char *p);
153 static bool fmt (FILE *f, char const *);
154 static bool get_paragraph (FILE *f);
155 static int get_line (FILE *f, int c);
156 static int get_prefix (FILE *f);
157 static int get_space (FILE *f, int c);
158 static int copy_rest (FILE *f, int c);
159 static bool same_para (int c);
160 static void flush_paragraph (void);
161 static void fmt_paragraph (void);
162 static void check_punctuation (WORD *w);
163 static COST base_cost (WORD *this);
164 static COST line_cost (WORD *next, int len);
165 static void put_paragraph (WORD *finish);
166 static void put_line (WORD *w, int indent);
167 static void put_word (WORD *w);
168 static void put_space (int space);
170 /* Option values. */
172 /* If true, first 2 lines may have different indent (default false). */
173 static bool crown;
175 /* If true, first 2 lines _must_ have different indent (default false). */
176 static bool tagged;
178 /* If true, each line is a paragraph on its own (default false). */
179 static bool split;
181 /* If true, don't preserve inter-word spacing (default false). */
182 static bool uniform;
184 /* Prefix minus leading and trailing spaces (default ""). */
185 static char const *prefix;
187 /* User-supplied maximum line width (default WIDTH). The only output
188 lines longer than this will each comprise a single word. */
189 static int max_width;
191 /* Values derived from the option values. */
193 /* The length of prefix minus leading space. */
194 static int prefix_full_length;
196 /* The length of the leading space trimmed from the prefix. */
197 static int prefix_lead_space;
199 /* The length of prefix minus leading and trailing space. */
200 static int prefix_length;
202 /* The preferred width of text lines, set to LEEWAY % less than max_width. */
203 static int goal_width;
205 /* Dynamic variables. */
207 /* Start column of the character most recently read from the input file. */
208 static int in_column;
210 /* Start column of the next character to be written to stdout. */
211 static int out_column;
213 /* Space for the paragraph text -- longer paragraphs are handled neatly
214 (cf. flush_paragraph()). */
215 static char parabuf[MAXCHARS];
217 /* A pointer into parabuf, indicating the first unused character position. */
218 static char *wptr;
220 /* The words of a paragraph -- longer paragraphs are handled neatly
221 (cf. flush_paragraph()). */
222 static WORD word[MAXWORDS];
224 /* A pointer into the above word array, indicating the first position
225 after the last complete word. Sometimes it will point at an incomplete
226 word. */
227 static WORD *word_limit;
229 /* If true, current input file contains tab characters, and so tabs can be
230 used for white space on output. */
231 static bool tabs;
233 /* Space before trimmed prefix on each line of the current paragraph. */
234 static int prefix_indent;
236 /* Indentation of the first line of the current paragraph. */
237 static int first_indent;
239 /* Indentation of other lines of the current paragraph */
240 static int other_indent;
242 /* To detect the end of a paragraph, we need to look ahead to the first
243 non-blank character after the prefix on the next line, or the first
244 character on the following line that failed to match the prefix.
245 We can reconstruct the lookahead from that character (next_char), its
246 position on the line (in_column) and the amount of space before the
247 prefix (next_prefix_indent). See get_paragraph() and copy_rest(). */
249 /* The last character read from the input file. */
250 static int next_char;
252 /* The space before the trimmed prefix (or part of it) on the next line
253 after the current paragraph. */
254 static int next_prefix_indent;
256 /* If nonzero, the length of the last line output in the current
257 paragraph, used to charge for raggedness at the split point for long
258 paragraphs chosen by fmt_paragraph(). */
259 static int last_line_length;
261 void
262 usage (int status)
264 if (status != EXIT_SUCCESS)
265 emit_try_help ();
266 else
268 printf (_("Usage: %s [-WIDTH] [OPTION]... [FILE]...\n"), program_name);
269 fputs (_("\
270 Reformat each paragraph in the FILE(s), writing to standard output.\n\
271 The option -WIDTH is an abbreviated form of --width=DIGITS.\n\
272 "), stdout);
274 emit_stdin_note ();
275 emit_mandatory_arg_note ();
277 fputs (_("\
278 -c, --crown-margin preserve indentation of first two lines\n\
279 -p, --prefix=STRING reformat only lines beginning with STRING,\n\
280 reattaching the prefix to reformatted lines\n\
281 -s, --split-only split long lines, but do not refill\n\
283 stdout);
284 /* Tell xgettext that the "% o" below is not a printf-style
285 format string: xgettext:no-c-format */
286 fputs (_("\
287 -t, --tagged-paragraph indentation of first line different from second\n\
288 -u, --uniform-spacing one space between words, two after sentences\n\
289 -w, --width=WIDTH maximum line width (default of 75 columns)\n\
290 -g, --goal=WIDTH goal width (default of 93% of width)\n\
291 "), stdout);
292 fputs (HELP_OPTION_DESCRIPTION, stdout);
293 fputs (VERSION_OPTION_DESCRIPTION, stdout);
294 emit_ancillary_info (PROGRAM_NAME);
296 exit (status);
299 /* Decode options and launch execution. */
301 static struct option const long_options[] =
303 {"crown-margin", no_argument, nullptr, 'c'},
304 {"prefix", required_argument, nullptr, 'p'},
305 {"split-only", no_argument, nullptr, 's'},
306 {"tagged-paragraph", no_argument, nullptr, 't'},
307 {"uniform-spacing", no_argument, nullptr, 'u'},
308 {"width", required_argument, nullptr, 'w'},
309 {"goal", required_argument, nullptr, 'g'},
310 {GETOPT_HELP_OPTION_DECL},
311 {GETOPT_VERSION_OPTION_DECL},
312 {nullptr, 0, nullptr, 0},
316 main (int argc, char **argv)
318 int optchar;
319 bool ok = true;
320 char const *max_width_option = nullptr;
321 char const *goal_width_option = nullptr;
323 initialize_main (&argc, &argv);
324 set_program_name (argv[0]);
325 setlocale (LC_ALL, "");
326 bindtextdomain (PACKAGE, LOCALEDIR);
327 textdomain (PACKAGE);
329 atexit (close_stdout);
331 crown = tagged = split = uniform = false;
332 max_width = WIDTH;
333 prefix = "";
334 prefix_length = prefix_lead_space = prefix_full_length = 0;
336 if (argc > 1 && argv[1][0] == '-' && ISDIGIT (argv[1][1]))
338 /* Old option syntax; a dash followed by one or more digits. */
339 max_width_option = argv[1] + 1;
341 /* Make the option we just parsed invisible to getopt. */
342 argv[1] = argv[0];
343 argv++;
344 argc--;
347 while ((optchar = getopt_long (argc, argv, "0123456789cstuw:p:g:",
348 long_options, nullptr))
349 != -1)
350 switch (optchar)
352 default:
353 if (ISDIGIT (optchar))
354 error (0, 0, _("invalid option -- %c; -WIDTH is recognized\
355 only when it is the first\noption; use -w N instead"),
356 optchar);
357 usage (EXIT_FAILURE);
359 case 'c':
360 crown = true;
361 break;
363 case 's':
364 split = true;
365 break;
367 case 't':
368 tagged = true;
369 break;
371 case 'u':
372 uniform = true;
373 break;
375 case 'w':
376 max_width_option = optarg;
377 break;
379 case 'g':
380 goal_width_option = optarg;
381 break;
383 case 'p':
384 set_prefix (optarg);
385 break;
387 case_GETOPT_HELP_CHAR;
389 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
393 if (max_width_option)
395 /* Limit max_width to MAXCHARS / 2; otherwise, the resulting
396 output can be quite ugly. */
397 max_width = xdectoumax (max_width_option, 0, MAXCHARS / 2, "",
398 _("invalid width"), 0);
401 if (goal_width_option)
403 /* Limit goal_width to max_width. */
404 goal_width = xdectoumax (goal_width_option, 0, max_width, "",
405 _("invalid width"), 0);
406 if (max_width_option == nullptr)
407 max_width = goal_width + 10;
409 else
411 goal_width = max_width * (2 * (100 - LEEWAY) + 1) / 200;
414 bool have_read_stdin = false;
416 if (optind == argc)
418 have_read_stdin = true;
419 ok = fmt (stdin, "-");
421 else
423 for (; optind < argc; optind++)
425 char *file = argv[optind];
426 if (STREQ (file, "-"))
428 ok &= fmt (stdin, file);
429 have_read_stdin = true;
431 else
433 FILE *in_stream;
434 in_stream = fopen (file, "r");
435 if (in_stream != nullptr)
436 ok &= fmt (in_stream, file);
437 else
439 error (0, errno, _("cannot open %s for reading"),
440 quoteaf (file));
441 ok = false;
447 if (have_read_stdin && fclose (stdin) != 0)
448 error (EXIT_FAILURE, errno, "%s", _("closing standard input"));
450 return ok ? EXIT_SUCCESS : EXIT_FAILURE;
453 /* Trim space from the front and back of the string P, yielding the prefix,
454 and record the lengths of the prefix and the space trimmed. */
456 static void
457 set_prefix (char *p)
459 char *s;
461 prefix_lead_space = 0;
462 while (*p == ' ')
464 prefix_lead_space++;
465 p++;
467 prefix = p;
468 prefix_full_length = strlen (p);
469 s = p + prefix_full_length;
470 while (s > p && s[-1] == ' ')
471 s--;
472 *s = '\0';
473 prefix_length = s - p;
476 /* Read F and send formatted output to stdout.
477 Close F when done, unless F is stdin. Diagnose input errors, using FILE.
478 If !F, assume F resulted from an fopen failure and diagnose that.
479 Return true if successful. */
481 static bool
482 fmt (FILE *f, char const *file)
484 fadvise (f, FADVISE_SEQUENTIAL);
485 tabs = false;
486 other_indent = 0;
487 next_char = get_prefix (f);
488 while (get_paragraph (f))
490 fmt_paragraph ();
491 put_paragraph (word_limit);
494 int err = ferror (f) ? 0 : -1;
495 if (f == stdin)
496 clearerr (f);
497 else if (fclose (f) != 0 && err < 0)
498 err = errno;
499 if (0 <= err)
500 error (0, err, err ? "%s" : _("read error"), quotef (file));
501 return err < 0;
504 /* Set the global variable 'other_indent' according to SAME_PARAGRAPH
505 and other global variables. */
507 static void
508 set_other_indent (bool same_paragraph)
510 if (split)
511 other_indent = first_indent;
512 else if (crown)
514 other_indent = (same_paragraph ? in_column : first_indent);
516 else if (tagged)
518 if (same_paragraph && in_column != first_indent)
520 other_indent = in_column;
523 /* Only one line: use the secondary indent from last time if it
524 splits, or 0 if there have been no multi-line paragraphs in the
525 input so far. But if these rules make the two indents the same,
526 pick a new secondary indent. */
528 else if (other_indent == first_indent)
529 other_indent = first_indent == 0 ? DEF_INDENT : 0;
531 else
533 other_indent = first_indent;
537 /* Read a paragraph from input file F. A paragraph consists of a
538 maximal number of non-blank (excluding any prefix) lines subject to:
539 * In split mode, a paragraph is a single non-blank line.
540 * In crown mode, the second and subsequent lines must have the
541 same indentation, but possibly different from the indent of the
542 first line.
543 * Tagged mode is similar, but the first and second lines must have
544 different indentations.
545 * Otherwise, all lines of a paragraph must have the same indent.
546 If a prefix is in effect, it must be present at the same indent for
547 each line in the paragraph.
549 Return false if end-of-file was encountered before the start of a
550 paragraph, else true. */
552 static bool
553 get_paragraph (FILE *f)
555 int c;
557 last_line_length = 0;
558 c = next_char;
560 /* Scan (and copy) blank lines, and lines not introduced by the prefix. */
562 while (c == '\n' || c == EOF
563 || next_prefix_indent < prefix_lead_space
564 || in_column < next_prefix_indent + prefix_full_length)
566 c = copy_rest (f, c);
567 if (c == EOF)
569 next_char = EOF;
570 return false;
572 putchar ('\n');
573 c = get_prefix (f);
576 /* Got a suitable first line for a paragraph. */
578 prefix_indent = next_prefix_indent;
579 first_indent = in_column;
580 wptr = parabuf;
581 word_limit = word;
582 c = get_line (f, c);
583 set_other_indent (same_para (c));
585 /* Read rest of paragraph (unless split is specified). */
587 if (split)
589 /* empty */
591 else if (crown)
593 if (same_para (c))
596 { /* for each line till the end of the para */
597 c = get_line (f, c);
599 while (same_para (c) && in_column == other_indent);
602 else if (tagged)
604 if (same_para (c) && in_column != first_indent)
607 { /* for each line till the end of the para */
608 c = get_line (f, c);
610 while (same_para (c) && in_column == other_indent);
613 else
615 while (same_para (c) && in_column == other_indent)
616 c = get_line (f, c);
619 (word_limit - 1)->period = (word_limit - 1)->final = true;
620 next_char = c;
621 return true;
624 /* Copy to the output a line that failed to match the prefix, or that
625 was blank after the prefix. In the former case, C is the character
626 that failed to match the prefix. In the latter, C is \n or EOF.
627 Return the character (\n or EOF) ending the line. */
629 static int
630 copy_rest (FILE *f, int c)
632 char const *s;
634 out_column = 0;
635 if (in_column > next_prefix_indent || (c != '\n' && c != EOF))
637 put_space (next_prefix_indent);
638 for (s = prefix; out_column != in_column && *s; out_column++)
639 putchar (*s++);
640 if (c != EOF && c != '\n')
641 put_space (in_column - out_column);
642 if (c == EOF && in_column >= next_prefix_indent + prefix_length)
643 putchar ('\n');
645 while (c != '\n' && c != EOF)
647 putchar (c);
648 c = getc (f);
650 return c;
653 /* Return true if a line whose first non-blank character after the
654 prefix (if any) is C could belong to the current paragraph,
655 otherwise false. */
657 static bool
658 same_para (int c)
660 return (next_prefix_indent == prefix_indent
661 && in_column >= next_prefix_indent + prefix_full_length
662 && c != '\n' && c != EOF);
665 /* Read a line from input file F, given first non-blank character C
666 after the prefix, and the following indent, and break it into words.
667 A word is a maximal non-empty string of non-white characters. A word
668 ending in [.?!][])"']* and followed by end-of-line or at least two
669 spaces ends a sentence, as in emacs.
671 Return the first non-blank character of the next line. */
673 static int
674 get_line (FILE *f, int c)
676 int start;
677 char *end_of_parabuf;
678 WORD *end_of_word;
680 end_of_parabuf = &parabuf[MAXCHARS];
681 end_of_word = &word[MAXWORDS - 2];
684 { /* for each word in a line */
686 /* Scan word. */
688 word_limit->text = wptr;
691 if (wptr == end_of_parabuf)
693 set_other_indent (true);
694 flush_paragraph ();
696 *wptr++ = c;
697 c = getc (f);
699 while (c != EOF && !c_isspace (c));
700 in_column += word_limit->length = wptr - word_limit->text;
701 check_punctuation (word_limit);
703 /* Scan inter-word space. */
705 start = in_column;
706 c = get_space (f, c);
707 word_limit->space = in_column - start;
708 word_limit->final = (c == EOF
709 || (word_limit->period
710 && (c == '\n' || word_limit->space > 1)));
711 if (c == '\n' || c == EOF || uniform)
712 word_limit->space = word_limit->final ? 2 : 1;
713 if (word_limit == end_of_word)
715 set_other_indent (true);
716 flush_paragraph ();
718 word_limit++;
720 while (c != '\n' && c != EOF);
721 return get_prefix (f);
724 /* Read a prefix from input file F. Return either first non-matching
725 character, or first non-blank character after the prefix. */
727 static int
728 get_prefix (FILE *f)
730 int c;
732 in_column = 0;
733 c = get_space (f, getc (f));
734 if (prefix_length == 0)
735 next_prefix_indent = prefix_lead_space < in_column ?
736 prefix_lead_space : in_column;
737 else
739 char const *p;
740 next_prefix_indent = in_column;
741 for (p = prefix; *p != '\0'; p++)
743 unsigned char pc = *p;
744 if (c != pc)
745 return c;
746 in_column++;
747 c = getc (f);
749 c = get_space (f, c);
751 return c;
754 /* Read blank characters from input file F, starting with C, and keeping
755 in_column up-to-date. Return first non-blank character. */
757 static int
758 get_space (FILE *f, int c)
760 while (true)
762 if (c == ' ')
763 in_column++;
764 else if (c == '\t')
766 tabs = true;
767 in_column = (in_column / TABWIDTH + 1) * TABWIDTH;
769 else
770 return c;
771 c = getc (f);
775 /* Set extra fields in word W describing any attached punctuation. */
777 static void
778 check_punctuation (WORD *w)
780 char const *start = w->text;
781 char const *finish = start + (w->length - 1);
782 unsigned char fin = *finish;
784 w->paren = isopen (*start);
785 w->punct = !! ispunct (fin);
786 while (start < finish && isclose (*finish))
787 finish--;
788 w->period = isperiod (*finish);
791 /* Flush part of the paragraph to make room. This function is called on
792 hitting the limit on the number of words or characters. */
794 static void
795 flush_paragraph (void)
797 WORD *split_point;
798 WORD *w;
799 int shift;
800 COST best_break;
802 /* In the special case where it's all one word, just flush it. */
804 if (word_limit == word)
806 fwrite (parabuf, sizeof *parabuf, wptr - parabuf, stdout);
807 wptr = parabuf;
808 return;
811 /* Otherwise:
812 - format what you have so far as a paragraph,
813 - find a low-cost line break near the end,
814 - output to there,
815 - make that the start of the paragraph. */
817 fmt_paragraph ();
819 /* Choose a good split point. */
821 split_point = word_limit;
822 best_break = MAXCOST;
823 for (w = word->next_break; w != word_limit; w = w->next_break)
825 if (w->best_cost - w->next_break->best_cost < best_break)
827 split_point = w;
828 best_break = w->best_cost - w->next_break->best_cost;
830 if (best_break <= MAXCOST - LINE_CREDIT)
831 best_break += LINE_CREDIT;
833 put_paragraph (split_point);
835 /* Copy text of words down to start of parabuf -- we use memmove because
836 the source and target may overlap. */
838 memmove (parabuf, split_point->text, wptr - split_point->text);
839 shift = split_point->text - parabuf;
840 wptr -= shift;
842 /* Adjust text pointers. */
844 for (w = split_point; w <= word_limit; w++)
845 w->text -= shift;
847 /* Copy words from split_point down to word -- we use memmove because
848 the source and target may overlap. */
850 memmove (word, split_point, (word_limit - split_point + 1) * sizeof *word);
851 word_limit -= split_point - word;
854 /* Compute the optimal formatting for the whole paragraph by computing
855 and remembering the optimal formatting for each suffix from the empty
856 one to the whole paragraph. */
858 static void
859 fmt_paragraph (void)
861 WORD *start, *w;
862 int len;
863 COST wcost, best;
864 int saved_length;
866 word_limit->best_cost = 0;
867 saved_length = word_limit->length;
868 word_limit->length = max_width; /* sentinel */
870 for (start = word_limit - 1; start >= word; start--)
872 best = MAXCOST;
873 len = start == word ? first_indent : other_indent;
875 /* At least one word, however long, in the line. */
877 w = start;
878 len += w->length;
881 w++;
883 /* Consider breaking before w. */
885 wcost = line_cost (w, len) + w->best_cost;
886 if (start == word && last_line_length > 0)
887 wcost += RAGGED_COST (len - last_line_length);
888 if (wcost < best)
890 best = wcost;
891 start->next_break = w;
892 start->line_length = len;
895 /* This is a kludge to keep us from computing 'len' as the
896 sum of the sentinel length and some non-zero number.
897 Since the sentinel w->length may be INT_MAX, adding
898 to that would give a negative result. */
899 if (w == word_limit)
900 break;
902 len += (w - 1)->space + w->length; /* w > start >= word */
904 while (len < max_width);
905 start->best_cost = best + base_cost (start);
908 word_limit->length = saved_length;
911 /* Work around <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109628>. */
912 #if 13 <= __GNUC__
913 # pragma GCC diagnostic ignored "-Wanalyzer-use-of-uninitialized-value"
914 #endif
916 /* Return the constant component of the cost of breaking before the
917 word THIS. */
919 static COST
920 base_cost (WORD *this)
922 COST cost;
924 cost = LINE_COST;
926 if (this > word)
928 if ((this - 1)->period)
930 if ((this - 1)->final)
931 cost -= SENTENCE_BONUS;
932 else
933 cost += NOBREAK_COST;
935 else if ((this - 1)->punct)
936 cost -= PUNCT_BONUS;
937 else if (this > word + 1 && (this - 2)->final)
938 cost += WIDOW_COST ((this - 1)->length);
941 if (this->paren)
942 cost -= PAREN_BONUS;
943 else if (this->final)
944 cost += ORPHAN_COST (this->length);
946 return cost;
949 /* Return the component of the cost of breaking before word NEXT that
950 depends on LEN, the length of the line beginning there. */
952 static COST
953 line_cost (WORD *next, int len)
955 int n;
956 COST cost;
958 if (next == word_limit)
959 return 0;
960 n = goal_width - len;
961 cost = SHORT_COST (n);
962 if (next->next_break != word_limit)
964 n = len - next->line_length;
965 cost += RAGGED_COST (n);
967 return cost;
970 /* Output to stdout a paragraph from word up to (but not including)
971 FINISH, which must be in the next_break chain from word. */
973 static void
974 put_paragraph (WORD *finish)
976 WORD *w;
978 put_line (word, first_indent);
979 for (w = word->next_break; w != finish; w = w->next_break)
980 put_line (w, other_indent);
983 /* Output to stdout the line beginning with word W, beginning in column
984 INDENT, including the prefix (if any). */
986 static void
987 put_line (WORD *w, int indent)
989 WORD *endline;
991 out_column = 0;
992 put_space (prefix_indent);
993 fputs (prefix, stdout);
994 out_column += prefix_length;
995 put_space (indent - out_column);
997 endline = w->next_break - 1;
998 for (; w != endline; w++)
1000 put_word (w);
1001 put_space (w->space);
1003 put_word (w);
1004 last_line_length = out_column;
1005 putchar ('\n');
1008 /* Output to stdout the word W. */
1010 static void
1011 put_word (WORD *w)
1013 char const *s;
1014 int n;
1016 s = w->text;
1017 for (n = w->length; n != 0; n--)
1018 putchar (*s++);
1019 out_column += w->length;
1022 /* Output to stdout SPACE spaces, or equivalent tabs. */
1024 static void
1025 put_space (int space)
1027 int space_target, tab_target;
1029 space_target = out_column + space;
1030 if (tabs)
1032 tab_target = space_target / TABWIDTH * TABWIDTH;
1033 if (out_column + 1 < tab_target)
1034 while (out_column < tab_target)
1036 putchar ('\t');
1037 out_column = (out_column / TABWIDTH + 1) * TABWIDTH;
1040 while (out_column < space_target)
1042 putchar (' ');
1043 out_column++;