1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 2010, 2011 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 <http://www.gnu.org/licenses/>. */
19 #include "language/lexer/scan.h"
24 #include "data/identifier.h"
25 #include "language/lexer/token.h"
26 #include "libpspp/assertion.h"
27 #include "libpspp/cast.h"
29 #include "gl/c-ctype.h"
30 #include "gl/c-strtod.h"
31 #include "gl/xmemdup0.h"
40 #define SS_NL_BEFORE_PLUS (1u << 0)
41 #define SS_PLUS (1u << 1)
42 #define SS_NL_AFTER_PLUS (1u << 2)
44 /* Returns the integer value of (hex) digit C. */
60 case 'a': case 'A': return 10;
61 case 'b': case 'B': return 11;
62 case 'c': case 'C': return 12;
63 case 'd': case 'D': return 13;
64 case 'e': case 'E': return 14;
65 case 'f': case 'F': return 15;
66 default: return INT_MAX;
71 scan_quoted_string__ (struct substring s, struct token *token)
75 /* Trim ' or " from front and back. */
76 quote = s.string[s.length - 1];
80 ss_realloc (&token->string, token->string.length + s.length + 1);
84 size_t pos = ss_find_byte (s, quote);
88 memcpy (ss_end (token->string), s.string, pos + 1);
89 token->string.length += pos + 1;
90 ss_advance (&s, pos + 2);
93 memcpy (ss_end (token->string), s.string, ss_length (s));
94 token->string.length += ss_length (s);
100 scan_hex_string__ (struct substring s, struct token *token)
105 /* Trim X' from front and ' from back. */
109 if (s.length % 2 != 0)
111 token->type = SCAN_BAD_HEX_LENGTH;
112 token->number = s.length;
116 ss_realloc (&token->string, token->string.length + s.length / 2 + 1);
117 dst = CHAR_CAST (uint8_t *, ss_end (token->string));
118 token->string.length += s.length / 2;
119 for (i = 0; i < s.length; i += 2)
121 int hi = digit_value (s.string[i]);
122 int lo = digit_value (s.string[i + 1]);
124 if (hi >= 16 || lo >= 16)
126 token->type = SCAN_BAD_HEX_DIGIT;
127 token->number = s.string[hi >= 16 ? i : i + 1];
131 *dst++ = hi * 16 + lo;
138 scan_unicode_string__ (struct substring s, struct token *token)
144 /* Trim U' from front and ' from back. */
148 if (s.length < 1 || s.length > 8)
150 token->type = SCAN_BAD_UNICODE_LENGTH;
151 token->number = s.length;
155 ss_realloc (&token->string, token->string.length + 4 + 1);
158 for (i = 0; i < s.length; i++)
160 int digit = digit_value (s.string[i]);
163 token->type = SCAN_BAD_UNICODE_DIGIT;
164 token->number = s.string[i];
167 uc = uc * 16 + digit;
170 if ((uc >= 0xd800 && uc < 0xe000) || uc > 0x10ffff)
172 token->type = SCAN_BAD_UNICODE_CODE_POINT;
177 dst = CHAR_CAST (uint8_t *, ss_end (token->string));
178 token->string.length += u8_uctomb (dst, uc, 4);
183 static enum scan_result
184 scan_string_segment__ (struct scanner *scanner, enum segment_type type,
185 struct substring s, struct token *token)
191 case SEG_QUOTED_STRING:
192 ok = scan_quoted_string__ (s, token);
196 ok = scan_hex_string__ (s, token);
199 case SEG_UNICODE_STRING:
200 ok = scan_unicode_string__ (s, token);
209 token->type = T_STRING;
210 token->string.string[token->string.length] = '\0';
211 scanner->state = S_STRING;
212 scanner->substate = 0;
217 /* The function we called above should have filled in token->type and
218 token->number properly to describe the error. */
219 ss_dealloc (&token->string);
220 token->string = ss_empty ();
226 static enum scan_result
227 add_bit (struct scanner *scanner, unsigned int bit)
229 if (!(scanner->substate & bit))
231 scanner->substate |= bit;
238 static enum scan_result
239 scan_string__ (struct scanner *scanner, enum segment_type type,
240 struct substring s, struct token *token)
249 if (scanner->substate & SS_PLUS)
250 return add_bit (scanner, SS_NL_AFTER_PLUS);
252 return add_bit (scanner, SS_NL_BEFORE_PLUS);
255 return (s.length == 1 && s.string[0] == '+'
256 ? add_bit (scanner, SS_PLUS)
259 case SEG_QUOTED_STRING:
261 case SEG_UNICODE_STRING:
262 return (scanner->substate & SS_PLUS
263 ? scan_string_segment__ (scanner, type, s, token)
271 static enum token_type
272 scan_reserved_word__ (struct substring word)
274 switch (c_toupper (word.string[0]))
283 return c_toupper (word.string[1]) == 'E' ? T_GE : T_GT;
286 return c_toupper (word.string[1]) == 'E' ? T_LE : T_LT;
289 return word.length == 2 ? T_NE : T_NOT;
298 return c_toupper (word.string[1]) == 'L' ? T_ALL : T_AND;
307 static enum token_type
308 scan_punct1__ (char c0)
312 case '(': return T_LPAREN;
313 case ')': return T_RPAREN;
314 case ',': return T_COMMA;
315 case '=': return T_EQUALS;
316 case '-': return T_DASH;
317 case '[': return T_LBRACK;
318 case ']': return T_RBRACK;
319 case '&': return T_AND;
320 case '|': return T_OR;
321 case '+': return T_PLUS;
322 case '/': return T_SLASH;
323 case '*': return T_ASTERISK;
324 case '<': return T_LT;
325 case '>': return T_GT;
326 case '~': return T_NOT;
332 static enum token_type
333 scan_punct2__ (char c0, char c1)
341 return c1 == '=' ? T_LE : T_NE;
359 static enum token_type
360 scan_punct__ (struct substring s)
362 return (s.length == 1
363 ? scan_punct1__ (s.string[0])
364 : scan_punct2__ (s.string[0], s.string[1]));
368 scan_number__ (struct substring s)
374 if (s.length < sizeof buf)
377 memcpy (buf, s.string, s.length);
378 buf[s.length] = '\0';
381 p = xmemdup0 (s.string, s.length);
383 number = c_strtod (p, NULL);
391 static enum scan_result
392 scan_unexpected_char (const struct substring *s, struct token *token)
396 token->type = SCAN_UNEXPECTED_CHAR;
397 u8_mbtouc (&uc, CHAR_CAST (const uint8_t *, s->string), s->length);
404 scan_type_to_string (enum scan_type type)
408 #define SCAN_TYPE(NAME) case SCAN_##NAME: return #NAME;
413 return token_type_to_name (type);
418 is_scan_type (enum scan_type type)
420 return type > SCAN_FIRST && type < SCAN_LAST;
423 static enum scan_result
424 scan_start__ (struct scanner *scanner, enum segment_type type,
425 struct substring s, struct token *token)
430 token->type = T_POS_NUM;
431 token->number = scan_number__ (s);
434 case SEG_QUOTED_STRING:
436 case SEG_UNICODE_STRING:
437 return scan_string_segment__ (scanner, type, s, token);
439 case SEG_UNQUOTED_STRING:
440 case SEG_DO_REPEAT_COMMAND:
441 case SEG_INLINE_DATA:
443 token->type = T_STRING;
444 ss_alloc_substring (&token->string, s);
447 case SEG_RESERVED_WORD:
448 token->type = scan_reserved_word__ (s);
453 ss_alloc_substring (&token->string, s);
457 if (s.length == 1 && s.string[0] == '-')
459 scanner->state = S_DASH;
464 token->type = scan_punct__ (s);
472 case SEG_COMMENT_COMMAND:
473 token->type = SCAN_SKIP;
476 case SEG_START_DOCUMENT:
478 ss_alloc_substring (&token->string, ss_cstr ("DOCUMENT"));
481 case SEG_START_COMMAND:
482 case SEG_SEPARATE_COMMANDS:
483 case SEG_END_COMMAND:
484 token->type = T_ENDCMD;
488 token->type = T_STOP;
491 case SEG_EXPECTED_QUOTE:
492 token->type = SCAN_EXPECTED_QUOTE;
495 case SEG_EXPECTED_EXPONENT:
496 token->type = SCAN_EXPECTED_EXPONENT;
497 ss_alloc_substring (&token->string, s);
500 case SEG_UNEXPECTED_DOT:
501 token->type = SCAN_UNEXPECTED_DOT;
504 case SEG_UNEXPECTED_CHAR:
505 return scan_unexpected_char (&s, token);
514 static enum scan_result
515 scan_dash__ (enum segment_type type, struct substring s, struct token *token)
524 token->type = T_NEG_NUM;
525 token->number = -scan_number__ (s);
529 token->type = T_DASH;
534 /* Initializes SCANNER for scanning a token from a sequence of segments.
535 Initializes TOKEN as the output token. (The client retains ownership of
536 TOKEN, but it must be preserved across subsequent calls to scanner_push()
539 A scanner only produces a single token. To obtain the next token,
540 re-initialize it by calling this function again.
542 A scanner does not contain any external references, so nothing needs to be
543 done to destroy one. For the same reason, scanners may be copied with plain
544 struct assignment (or memcpy). */
546 scanner_init (struct scanner *scanner, struct token *token)
548 scanner->state = S_START;
552 /* Adds the segment with type TYPE and UTF-8 text S to SCANNER. TOKEN must be
553 the same token passed to scanner_init() for SCANNER, or a copy of it.
554 scanner_push() may modify TOKEN. The client retains ownership of TOKEN,
556 The possible return values are:
558 - SCAN_DONE: All of the segments that have been passed to scanner_push()
559 form the token now stored in TOKEN. SCANNER is now "used up" and must
560 be reinitialized with scanner_init() if it is to be used again.
562 Most tokens only consist of a single segment, so this is the most common
565 - SCAN_MORE: The segments passed to scanner_push() don't yet determine a
566 token. The caller should call scanner_push() again with the next token.
567 (This won't happen if TYPE is SEG_END indicating the end of input.)
569 - SCAN_SAVE: This is similar to SCAN_MORE, with one difference: the caller
570 needs to "save its place" in the stream of segments for a possible
571 future SCAN_BACK return. This value can be returned more than once in a
572 sequence of scanner_push() calls for SCANNER, but the caller only needs
573 to keep track of the most recent position.
575 - SCAN_BACK: This is similar to SCAN_DONE, but the token consists of only
576 the segments up to and including the segment for which SCAN_SAVE was
577 most recently returned. Segments following that one should be passed to
578 the next scanner to be initialized.
581 scanner_push (struct scanner *scanner, enum segment_type type,
582 struct substring s, struct token *token)
584 switch (scanner->state)
587 return scan_start__ (scanner, type, s, token);
590 return scan_dash__ (type, s, token);
593 return scan_string__ (scanner, type, s, token);