1 /* Locations for Bison
2 
3    Copyright (C) 2002, 2005-2012 Free Software Foundation, Inc.
4 
5    This file is part of Bison, the GNU Compiler Compiler.
6 
7    This program is free software: you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation, either version 3 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19 
20 #include <config.h>
21 #include "system.h"
22 
23 #include <mbswidth.h>
24 #include <quotearg.h>
25 
26 #include "complain.h"
27 #include "location.h"
28 
29 location const empty_location = EMPTY_LOCATION_INIT;
30 
31 /* If BUF is null, add BUFSIZE (which in this case must be less than
32    INT_MAX) to COLUMN; otherwise, add mbsnwidth (BUF, BUFSIZE, 0) to
33    COLUMN.  If an overflow occurs, or might occur but is undetectable,
34    return INT_MAX.  Assume COLUMN is nonnegative.  */
35 
36 static inline int
add_column_width(int column,char const * buf,size_t bufsize)37 add_column_width (int column, char const *buf, size_t bufsize)
38 {
39   size_t width;
40   unsigned int remaining_columns = INT_MAX - column;
41 
42   if (buf)
43     {
44       if (INT_MAX / 2 <= bufsize)
45 	return INT_MAX;
46       width = mbsnwidth (buf, bufsize, 0);
47     }
48   else
49     width = bufsize;
50 
51   return width <= remaining_columns ? column + width : INT_MAX;
52 }
53 
54 /* Set *LOC and adjust scanner cursor to account for token TOKEN of
55    size SIZE.  */
56 
57 void
location_compute(location * loc,boundary * cur,char const * token,size_t size)58 location_compute (location *loc, boundary *cur, char const *token, size_t size)
59 {
60   int line = cur->line;
61   int column = cur->column;
62   char const *p0 = token;
63   char const *p = token;
64   char const *lim = token + size;
65 
66   loc->start = *cur;
67 
68   for (p = token; p < lim; p++)
69     switch (*p)
70       {
71       case '\n':
72 	line += line < INT_MAX;
73 	column = 1;
74 	p0 = p + 1;
75 	break;
76 
77       case '\t':
78 	column = add_column_width (column, p0, p - p0);
79 	column = add_column_width (column, NULL, 8 - ((column - 1) & 7));
80 	p0 = p + 1;
81 	break;
82 
83       default:
84 	break;
85       }
86 
87   cur->line = line;
88   cur->column = column = add_column_width (column, p0, p - p0);
89 
90   loc->end = *cur;
91 
92   if (line == INT_MAX && loc->start.line != INT_MAX)
93     warn_at (*loc, _("line number overflow"));
94   if (column == INT_MAX && loc->start.column != INT_MAX)
95     warn_at (*loc, _("column number overflow"));
96 }
97 
98 
99 /* Output to OUT the location LOC.
100    Warning: it uses quotearg's slot 3.  */
101 unsigned
location_print(FILE * out,location loc)102 location_print (FILE *out, location loc)
103 {
104   unsigned res = 0;
105   int end_col = 0 != loc.end.column ? loc.end.column - 1 : 0;
106   res += fprintf (out, "%s",
107                   quotearg_n_style (3, escape_quoting_style, loc.start.file));
108   if (0 <= loc.start.line)
109     {
110       res += fprintf (out, ":%d", loc.start.line);
111       if (0 <= loc.start.column)
112         res += fprintf (out, ".%d", loc.start.column);
113     }
114   if (loc.start.file != loc.end.file)
115     {
116       res += fprintf (out, "-%s",
117                       quotearg_n_style (3, escape_quoting_style,
118                                         loc.end.file));
119       if (0 <= loc.end.line)
120         {
121           res += fprintf (out, ":%d", loc.end.line);
122           if (0 <= end_col)
123             res += fprintf (out, ".%d", end_col);
124         }
125     }
126   else if (0 <= loc.end.line)
127     {
128       if (loc.start.line < loc.end.line)
129         {
130           res += fprintf (out, "-%d", loc.end.line);
131           if (0 <= end_col)
132             res += fprintf (out, ".%d", end_col);
133         }
134       else if (0 <= end_col && loc.start.column < end_col)
135         res += fprintf (out, "-%d", end_col);
136     }
137 
138   return res;
139 }
140 
141 
142 /* Persistant data used by location_caret to avoid reopening and rereading the
143    same file all over for each error.  */
144 struct caret_info
145 {
146   FILE *source;
147   size_t line;
148   size_t offset;
149 };
150 
151 static struct caret_info caret_info = { NULL, 1, 0 };
152 
153 void
cleanup_caret()154 cleanup_caret ()
155 {
156   if (caret_info.source)
157     fclose (caret_info.source);
158 }
159 
160 void
location_caret(FILE * out,location loc)161 location_caret (FILE *out, location loc)
162 {
163   /* FIXME: find a way to support multifile locations, and only open once each
164      file. That would make the procedure future-proof.  */
165   if (! (caret_info.source
166          || (caret_info.source = fopen (loc.start.file, "r")))
167       || loc.start.column == -1 || loc.start.line == -1)
168     return;
169 
170   /* If the line we want to quote is seekable (the same line as the previous
171      location), just seek it. If it was before, we lost track of it, so
172      return to the start of file.  */
173   if (caret_info.line <= loc.start.line)
174     fseek (caret_info.source, caret_info.offset, SEEK_SET);
175   else
176     {
177       caret_info.line = 1;
178       caret_info.offset = 0;
179       fseek (caret_info.source, caret_info.offset, SEEK_SET);
180     }
181 
182   /* Advance to the line's position, keeping track of the offset.  */
183   while (caret_info.line < loc.start.line)
184     caret_info.line += fgetc (caret_info.source) == '\n';
185   caret_info.offset = ftell (caret_info.source);
186 
187   /* Read the actual line.  Don't update the offset, so that we keep a pointer
188      to the start of the line.  */
189   {
190     char *buf = NULL;
191     size_t size = 0;
192     ssize_t len = getline (&buf, &size, caret_info.source);
193     if (0 < len)
194       {
195         /* The caret of a multiline location ends with the first line.  */
196         int end = loc.start.line != loc.end.line ? len : loc.end.column;
197 
198         /* Quote the file, indent by a single column.  */
199         fputc (' ', out);
200         fwrite (buf, 1, len, out);
201 
202         /* Print the caret, with the same indent as above.  */
203         fprintf (out, " %*s", loc.start.column - 1, "");
204         {
205           int i = loc.start.column;
206           do
207             fputc ('^', out);
208           while (++i < end);
209         }
210         fputc ('\n', out);
211       }
212     free (buf);
213   }
214 }
215 
216 void
boundary_set_from_string(boundary * bound,char * loc_str)217 boundary_set_from_string (boundary *bound, char *loc_str)
218 {
219   /* Must search in reverse since the file name field may
220    * contain `.' or `:'.  */
221   char *delim = mbsrchr (loc_str, '.');
222   aver (delim);
223   *delim = '\0';
224   bound->column = atoi (delim+1);
225   delim = mbsrchr (loc_str, ':');
226   aver (delim);
227   *delim = '\0';
228   bound->line = atoi (delim+1);
229   bound->file = uniqstr_new (loc_str);
230 }
231