Mercurial > botc / file comparison

comparison: scriptreader.cxx

scriptreader.cxx

changeset 71
11f23fabf8a6
parent 70
fc257920ac00
child 72
03e4d9db3fd9
equal deleted inserted replaced
70:fc257920ac00 71:11f23fabf8a6
1 /*
2 * botc source code
3 * Copyright (C) 2012 Santeri `Dusk` Piippo
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 * 3. Neither the name of the developer nor the names of its contributors may
15 * be used to endorse or promote products derived from this software without
16 * specific prior written permission.
17 * 4. Redistributions in any form must be accompanied by information on how to
18 * obtain complete source code for the software and any accompanying
19 * software that uses the software. The source code must either be included
20 * in the distribution or be available for no more than the cost of
21 * distribution plus a nominal fee, and must be freely redistributable
22 * under reasonable conditions. For an executable file, complete source
23 * code means the source code for all modules it contains. It does not
24 * include source code for modules or files that typically accompany the
25 * major components of the operating system on which the executable file
26 * runs.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
29 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
32 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 */
40
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include "string.h"
44 #include "str.h"
45 #include "common.h"
46 #include "scriptreader.h"
47
48 #define STORE_POSITION \
49 bool _atnewline = atnewline; \
50 unsigned int _curline = curline[fc]; \
51 unsigned int _curchar = curchar[fc];
52
53 #define RESTORE_POSITION \
54 atnewline = _atnewline; \
55 curline[fc] = _curline; \
56 curchar[fc] = _curchar;
57
58 // ============================================================================
59 ScriptReader::ScriptReader (str path) {
60 token = "";
61 prevtoken = "";
62 prevpos = 0;
63 fc = -1;
64
65 for (unsigned int u = 0; u < MAX_FILESTACK; u++)
66 fp[u] = NULL;
67
68 OpenFile (path);
69 commentmode = 0;
70 }
71
72 // ============================================================================
73 ScriptReader::~ScriptReader () {
74 // If comment mode is 2 by the time the file ended, the
75 // comment was left unterminated. 1 is no problem, since
76 // it's terminated by newlines anyway.
77 if (commentmode == 2)
78 ParserError ("unterminated `/*`-style comment");
79
80 for (unsigned int u = 0; u < MAX_FILESTACK; u++) {
81 if (fp[u]) {
82 ParserWarning ("file idx %u remained open after parsing", u);
83 CloseFile (u);
84 }
85 }
86 }
87
88 // ============================================================================
89 // Opens a file and pushes its pointer to stack
90 void ScriptReader::OpenFile (str path) {
91 if (fc+1 >= MAX_FILESTACK)
92 ParserError ("supposed to open file `%s` but file stack is full! do you have recursive `#include` directives?",
93 path.chars());
94
95 // Save the position first.
96 if (fc != -1) {
97 savedpos[fc] = ftell (fp[fc]);
98 }
99
100 fc++;
101
102 fp[fc] = fopen (path, "r");
103 if (!fp[fc]) {
104 ParserError ("couldn't open %s for reading!\n", path.chars ());
105 exit (1);
106 }
107
108 fseek (fp[fc], 0, SEEK_SET);
109 filepath[fc] = path.chars();
110 curline[fc] = 1;
111 curchar[fc] = 1;
112 pos[fc] = 0;
113 atnewline = 0;
114 }
115
116 // ============================================================================
117 // Closes the current file
118 void ScriptReader::CloseFile (unsigned int u) {
119 if (u >= MAX_FILESTACK)
120 u = fc;
121
122 if (!fp[u])
123 return;
124
125 fclose (fp[u]);
126 fp[u] = NULL;
127 fc--;
128
129 if (fc != -1)
130 fseek (fp[fc], savedpos[fc], SEEK_SET);
131 }
132
133 // ============================================================================
134 char ScriptReader::ReadChar () {
135 if (feof (fp[fc]))
136 return 0;
137
138 char c;
139 if (!fread (&c, 1, 1, fp[fc]))
140 return 0;
141
142 // We're at a newline, thus next char read will begin the next line
143 if (atnewline) {
144 atnewline = false;
145 curline[fc]++;
146 curchar[fc] = 0; // gets incremented to 1
147 }
148
149 if (c == '\n') {
150 atnewline = true;
151
152 // Check for pre-processor directives
153 PreprocessDirectives ();
154 }
155
156 curchar[fc]++;
157 return c;
158 }
159
160 // ============================================================================
161 // Peeks the next character
162 char ScriptReader::PeekChar (int offset) {
163 // Store current position
164 long curpos = ftell (fp[fc]);
165 STORE_POSITION
166
167 // Forward by offset
168 fseek (fp[fc], offset, SEEK_CUR);
169
170 // Read the character
171 char* c = (char*)malloc (sizeof (char));
172
173 if (!fread (c, sizeof (char), 1, fp[fc])) {
174 fseek (fp[fc], curpos, SEEK_SET);
175 return 0;
176 }
177
178 // Rewind back
179 fseek (fp[fc], curpos, SEEK_SET);
180 RESTORE_POSITION
181
182 return c[0];
183 }
184
185 // ============================================================================
186 // Read a token from the file buffer. Returns true if token was found, false if not.
187 bool ScriptReader::Next (bool peek) {
188 prevpos = ftell (fp[fc]);
189 str tmp = "";
190
191 while (1) {
192 // Check end-of-file
193 if (feof (fp[fc])) {
194 // If we're just peeking, we shouldn't
195 // actually close anything..
196 if (peek)
197 break;
198
199 CloseFile ();
200 if (fc == -1)
201 break;
202 }
203
204 // Check if the next token possibly starts a comment.
205 if (PeekChar () == '/' && !tmp.len()) {
206 char c2 = PeekChar (1);
207 // C++-style comment
208 if (c2 == '/')
209 commentmode = 1;
210 else if (c2 == '*')
211 commentmode = 2;
212
213 // We don't need to actually read in the
214 // comment characters, since they will get
215 // ignored due to comment mode anyway.
216 }
217
218 c = ReadChar ();
219
220 // If this is a comment we're reading, check if this character
221 // gets the comment terminated, otherwise ignore it.
222 if (commentmode > 0) {
223 if (commentmode == 1 && c == '\n') {
224 // C++-style comments are terminated by a newline
225 commentmode = 0;
226 continue;
227 } else if (commentmode == 2 && c == '*') {
228 // C-style comments are terminated by a `*/`
229 if (PeekChar() == '/') {
230 commentmode = 0;
231 ReadChar ();
232 }
233 }
234
235 // Otherwise, ignore it.
236 continue;
237 }
238
239 // Non-alphanumber characters (sans underscore) break the word too.
240 // If there was prior data, the delimeter pushes the cursor back so
241 // that the next character will be the same delimeter. If there isn't,
242 // the delimeter itself is included (and thus becomes a token itself.)
243 if ((c >= 33 && c <= 47) ||
244 (c >= 58 && c <= 64) ||
245 (c >= 91 && c <= 96 && c != '_') ||
246 (c >= 123 && c <= 126)) {
247 if (tmp.len())
248 fseek (fp[fc], ftell (fp[fc]) - 1, SEEK_SET);
249 else
250 tmp += c;
251 break;
252 }
253
254 if (IsCharWhitespace (c)) {
255 // Don't break if we haven't gathered anything yet.
256 if (tmp.len())
257 break;
258 } else {
259 tmp += c;
260 }
261 }
262
263 // If we got nothing here, read failed. This should
264 // only happen in the case of EOF.
265 if (!tmp.len()) {
266 token = "";
267 return false;
268 }
269
270 pos[fc]++;
271 prevtoken = token;
272 token = tmp;
273 return true;
274 }
275
276 // ============================================================================
277 // Returns the next token without advancing the cursor.
278 str ScriptReader::PeekNext (int offset) {
279 // Store current information
280 str storedtoken = token;
281 int cpos = ftell (fp[fc]);
282 STORE_POSITION
283
284 // Advance on the token.
285 while (offset >= 0) {
286 if (!Next (true))
287 return "";
288 offset--;
289 }
290
291 str tmp = token;
292
293 // Restore position
294 fseek (fp[fc], cpos, SEEK_SET);
295 pos[fc]--;
296 token = storedtoken;
297 RESTORE_POSITION
298 return tmp;
299 }
300
301 // ============================================================================
302 void ScriptReader::Seek (unsigned int n, int origin) {
303 switch (origin) {
304 case SEEK_SET:
305 fseek (fp[fc], 0, SEEK_SET);
306 pos[fc] = 0;
307 break;
308 case SEEK_CUR:
309 break;
310 case SEEK_END:
311 printf ("ScriptReader::Seek: SEEK_END not yet supported.\n");
312 break;
313 }
314
315 for (unsigned int i = 0; i < n+1; i++)
316 Next();
317 }
318
319 // ============================================================================
320 void ScriptReader::MustNext (const char* c) {
321 if (!Next()) {
322 if (strlen (c))
323 ParserError ("expected `%s`, reached end of file instead\n", c);
324 else
325 ParserError ("expected a token, reached end of file instead\n");
326 }
327
328 if (strlen (c))
329 MustThis (c);
330 }
331
332 // ============================================================================
333 void ScriptReader::MustThis (const char* c) {
334 if (token != c)
335 ParserError ("expected `%s`, got `%s` instead", c, token.chars());
336 }
337
338 // ============================================================================
339 void ScriptReader::ParserError (const char* message, ...) {
340 PERFORM_FORMAT (message, outmessage);
341 ParserMessage ("\nError: ", outmessage);
342 exit (1);
343 }
344
345 // ============================================================================
346 void ScriptReader::ParserWarning (const char* message, ...) {
347 PERFORM_FORMAT (message, outmessage);
348 ParserMessage ("Warning: ", outmessage);
349 }
350
351 // ============================================================================
352 void ScriptReader::ParserMessage (const char* header, char* message) {
353 if (fc >= 0 && fc < MAX_FILESTACK)
354 fprintf (stderr, "%s%s:%u:%u: %s\n",
355 header, filepath[fc], curline[fc], curchar[fc], message);
356 else
357 fprintf (stderr, "%s%s\n", header, message);
358 }
359
360 // ============================================================================
361 // if gotquote == 1, the current token already holds the quotation mark.
362 void ScriptReader::MustString (bool gotquote) {
363 if (gotquote)
364 MustThis ("\"");
365 else
366 MustNext ("\"");
367
368 str string;
369 // Keep reading characters until we find a terminating quote.
370 while (1) {
371 // can't end here!
372 if (feof (fp[fc]))
373 ParserError ("unterminated string");
374
375 char c = ReadChar ();
376 if (c == '"')
377 break;
378
379 string += c;
380 }
381
382 token = string;
383 }
384
385 // ============================================================================
386 void ScriptReader::MustNumber (bool fromthis) {
387 if (!fromthis)
388 MustNext ();
389
390 str num = token;
391 if (num == "-") {
392 MustNext ();
393 num += token;
394 }
395
396 // "true" and "false" are valid numbers
397 if (!token.icompare ("true"))
398 token = "1";
399 else if (!token.icompare ("false"))
400 token = "0";
401 else {
402 if (!token.isnumber())
403 ParserError ("expected a number, got `%s`", num.chars());
404
405 str check;
406 check.appendformat ("%d", atoi (num));
407 if (token != check)
408 ParserWarning ("integer too large: %s -> %s", num.chars(), check.chars());
409
410 token = num;
411 }
412 }

Mercurial Repository: botc

mercurial