1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 2010, 2011, 2013 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"
28 #include "libpspp/i18n.h"
30 #include "gl/c-ctype.h"
31 #include "gl/c-strtod.h"
32 #include "gl/xmemdup0.h"
35 #define _(msgid) gettext (msgid)
44 #define SS_NL_BEFORE_PLUS (1u << 0)
45 #define SS_PLUS (1u << 1)
46 #define SS_NL_AFTER_PLUS (1u << 2)
48 /* Returns the integer value of (hex) digit C. */
64 case 'a': case 'A': return 10;
65 case 'b': case 'B': return 11;
66 case 'c': case 'C': return 12;
67 case 'd': case 'D': return 13;
68 case 'e': case 'E': return 14;
69 case 'f': case 'F': return 15;
70 default: return INT_MAX;
75 scan_quoted_string__ (struct substring s, struct token *token)
79 /* Trim ' or " from front and back. */
80 quote = s.string[s.length - 1];
84 ss_realloc (&token->string, token->string.length + s.length + 1);
88 size_t pos = ss_find_byte (s, quote);
92 memcpy (ss_end (token->string), s.string, pos + 1);
93 token->string.length += pos + 1;
94 ss_advance (&s, pos + 2);
97 memcpy (ss_end (token->string), s.string, ss_length (s));
98 token->string.length += ss_length (s);
104 scan_hex_string__ (struct substring s, struct token *token)
109 /* Trim X' from front and ' from back. */
113 if (s.length % 2 != 0)
115 token->type = SCAN_BAD_HEX_LENGTH;
116 token->number = s.length;
120 ss_realloc (&token->string, token->string.length + s.length / 2 + 1);
121 dst = CHAR_CAST (uint8_t *, ss_end (token->string));
122 token->string.length += s.length / 2;
123 for (i = 0; i < s.length; i += 2)
125 int hi = digit_value (s.string[i]);
126 int lo = digit_value (s.string[i + 1]);
128 if (hi >= 16 || lo >= 16)
130 token->type = SCAN_BAD_HEX_DIGIT;
131 token->number = s.string[hi >= 16 ? i : i + 1];
135 *dst++ = hi * 16 + lo;
142 scan_unicode_string__ (struct substring s, struct token *token)
148 /* Trim U' from front and ' from back. */
152 if (s.length < 1 || s.length > 8)
154 token->type = SCAN_BAD_UNICODE_LENGTH;
155 token->number = s.length;
159 ss_realloc (&token->string, token->string.length + 4 + 1);
162 for (i = 0; i < s.length; i++)
164 int digit = digit_value (s.string[i]);
167 token->type = SCAN_BAD_UNICODE_DIGIT;
168 token->number = s.string[i];
171 uc = uc * 16 + digit;
174 if ((uc >= 0xd800 && uc < 0xe000) || uc > 0x10ffff)
176 token->type = SCAN_BAD_UNICODE_CODE_POINT;
181 dst = CHAR_CAST (uint8_t *, ss_end (token->string));
182 token->string.length += u8_uctomb (dst, uc, 4);
187 static enum scan_result
188 scan_string_segment__ (struct scanner *scanner, enum segment_type type,
189 struct substring s, struct token *token)
195 case SEG_QUOTED_STRING:
196 ok = scan_quoted_string__ (s, token);
200 ok = scan_hex_string__ (s, token);
203 case SEG_UNICODE_STRING:
204 ok = scan_unicode_string__ (s, token);
213 token->type = T_STRING;
214 token->string.string[token->string.length] = '\0';
215 scanner->state = S_STRING;
216 scanner->substate = 0;
221 /* The function we called above should have filled in token->type and
222 token->number properly to describe the error. */
223 ss_dealloc (&token->string);
224 token->string = ss_empty ();
230 static enum scan_result
231 add_bit (struct scanner *scanner, unsigned int bit)
233 if (!(scanner->substate & bit))
235 scanner->substate |= bit;
242 static enum scan_result
243 scan_string__ (struct scanner *scanner, enum segment_type type,
244 struct substring s, struct token *token)
253 if (scanner->substate & SS_PLUS)
254 return add_bit (scanner, SS_NL_AFTER_PLUS);
256 return add_bit (scanner, SS_NL_BEFORE_PLUS);
259 return (s.length == 1 && s.string[0] == '+'
260 ? add_bit (scanner, SS_PLUS)
263 case SEG_QUOTED_STRING:
265 case SEG_UNICODE_STRING:
266 return (scanner->substate & SS_PLUS
267 ? scan_string_segment__ (scanner, type, s, token)
275 static enum token_type
276 scan_reserved_word__ (struct substring word)
278 switch (c_toupper (word.string[0]))
287 return c_toupper (word.string[1]) == 'E' ? T_GE : T_GT;
290 return c_toupper (word.string[1]) == 'E' ? T_LE : T_LT;
293 return word.length == 2 ? T_NE : T_NOT;
302 return c_toupper (word.string[1]) == 'L' ? T_ALL : T_AND;
311 static enum token_type
312 scan_punct1__ (char c0)
316 case '(': return T_LPAREN;
317 case ')': return T_RPAREN;
318 case ',': return T_COMMA;
319 case '=': return T_EQUALS;
320 case '-': return T_DASH;
321 case '[': return T_LBRACK;
322 case ']': return T_RBRACK;
323 case '&': return T_AND;
324 case '|': return T_OR;
325 case '+': return T_PLUS;
326 case '/': return T_SLASH;
327 case '*': return T_ASTERISK;
328 case '<': return T_LT;
329 case '>': return T_GT;
330 case '~': return T_NOT;
331 default: return T_MACRO_PUNCT;
337 static enum token_type
338 scan_punct2__ (char c0, char c1)
346 return c1 == '=' ? T_LE : T_NE;
364 static enum token_type
365 scan_punct__ (struct substring s)
367 return (s.length == 1
368 ? scan_punct1__ (s.string[0])
369 : scan_punct2__ (s.string[0], s.string[1]));
373 scan_number__ (struct substring s)
379 if (s.length < sizeof buf)
382 memcpy (buf, s.string, s.length);
383 buf[s.length] = '\0';
386 p = xmemdup0 (s.string, s.length);
388 number = c_strtod (p, NULL);
396 static enum scan_result
397 scan_unexpected_char (const struct substring *s, struct token *token)
401 token->type = SCAN_UNEXPECTED_CHAR;
402 u8_mbtouc (&uc, CHAR_CAST (const uint8_t *, s->string), s->length);
409 scan_type_to_string (enum scan_type type)
413 #define SCAN_TYPE(NAME) case SCAN_##NAME: return #NAME;
418 return token_type_to_name ((enum token_type) type);
423 is_scan_type (enum scan_type type)
425 return type > SCAN_FIRST && type < SCAN_LAST;
428 /* If TOKEN has the type of a scan error (a subset of those identified by
429 is_scan_type()), returns an appropriate error message. Otherwise, returns
432 scan_token_to_error (const struct token *token)
436 case SCAN_BAD_HEX_LENGTH:
437 return xasprintf (_("String of hex digits has %d characters, which "
438 "is not a multiple of 2."), (int) token->number);
440 case SCAN_BAD_HEX_DIGIT:
441 case SCAN_BAD_UNICODE_DIGIT:
442 return xasprintf (_("`%c' is not a valid hex digit."),
443 (int) token->number);
445 case SCAN_BAD_UNICODE_LENGTH:
446 return xasprintf (_("Unicode string contains %d bytes, which is "
447 "not in the valid range of 1 to 8 bytes."),
448 (int) token->number);
450 case SCAN_BAD_UNICODE_CODE_POINT:
451 return xasprintf (_("U+%04X is not a valid Unicode code point."),
452 (int) token->number);
454 case SCAN_EXPECTED_QUOTE:
455 return xasprintf (_("Unterminated string constant."));
457 case SCAN_EXPECTED_EXPONENT:
458 return xasprintf (_("Missing exponent following `%s'."),
459 token->string.string);
461 case SCAN_UNEXPECTED_CHAR:
463 return xasprintf (_("Bad character %s in input."),
464 uc_name (token->number, c_name));
470 static enum scan_result
471 scan_start__ (struct scanner *scanner, enum segment_type type,
472 struct substring s, struct token *token)
477 token->type = T_POS_NUM;
478 token->number = scan_number__ (s);
481 case SEG_QUOTED_STRING:
483 case SEG_UNICODE_STRING:
484 return scan_string_segment__ (scanner, type, s, token);
486 case SEG_UNQUOTED_STRING:
487 case SEG_DO_REPEAT_COMMAND:
488 case SEG_INLINE_DATA:
491 token->type = T_STRING;
492 ss_alloc_substring (&token->string, s);
495 case SEG_RESERVED_WORD:
496 token->type = scan_reserved_word__ (s);
501 ss_alloc_substring (&token->string, s);
505 token->type = T_MACRO_ID;
506 ss_alloc_substring (&token->string, s);
510 if (s.length == 1 && s.string[0] == '-')
512 scanner->state = S_DASH;
517 token->type = scan_punct__ (s);
518 if (token->type == T_MACRO_PUNCT)
519 ss_alloc_substring (&token->string, s);
527 case SEG_COMMENT_COMMAND:
528 token->type = SCAN_SKIP;
531 case SEG_START_DOCUMENT:
533 ss_alloc_substring (&token->string, ss_cstr ("DOCUMENT"));
536 case SEG_START_COMMAND:
537 case SEG_SEPARATE_COMMANDS:
538 case SEG_END_COMMAND:
539 token->type = T_ENDCMD;
543 token->type = T_STOP;
546 case SEG_EXPECTED_QUOTE:
547 token->type = SCAN_EXPECTED_QUOTE;
550 case SEG_EXPECTED_EXPONENT:
551 token->type = SCAN_EXPECTED_EXPONENT;
552 ss_alloc_substring (&token->string, s);
555 case SEG_UNEXPECTED_CHAR:
556 return scan_unexpected_char (&s, token);
562 static enum scan_result
563 scan_dash__ (enum segment_type type, struct substring s, struct token *token)
572 token->type = T_NEG_NUM;
573 token->number = -scan_number__ (s);
577 token->type = T_DASH;
582 /* Initializes SCANNER for scanning a token from a sequence of segments.
583 Initializes TOKEN as the output token. (The client retains ownership of
584 TOKEN, but it must be preserved across subsequent calls to scanner_push()
587 A scanner only produces a single token. To obtain the next token,
588 re-initialize it by calling this function again.
590 A scanner does not contain any external references, so nothing needs to be
591 done to destroy one. For the same reason, scanners may be copied with plain
592 struct assignment (or memcpy). */
594 scanner_init (struct scanner *scanner, struct token *token)
596 scanner->state = S_START;
600 /* Adds the segment with type TYPE and UTF-8 text S to SCANNER. TOKEN must be
601 the same token passed to scanner_init() for SCANNER, or a copy of it.
602 scanner_push() may modify TOKEN. The client retains ownership of TOKEN,
604 The possible return values are:
606 - SCAN_DONE: All of the segments that have been passed to scanner_push()
607 form the token now stored in TOKEN. SCANNER is now "used up" and must
608 be reinitialized with scanner_init() if it is to be used again.
610 Most tokens only consist of a single segment, so this is the most common
613 - SCAN_MORE: The segments passed to scanner_push() don't yet determine a
614 token. The caller should call scanner_push() again with the next token.
615 (This won't happen if TYPE is SEG_END indicating the end of input.)
617 - SCAN_SAVE: This is similar to SCAN_MORE, with one difference: the caller
618 needs to "save its place" in the stream of segments for a possible
619 future SCAN_BACK return. This value can be returned more than once in a
620 sequence of scanner_push() calls for SCANNER, but the caller only needs
621 to keep track of the most recent position.
623 - SCAN_BACK: This is similar to SCAN_DONE, but the token consists of only
624 the segments up to and including the segment for which SCAN_SAVE was
625 most recently returned. Segments following that one should be passed to
626 the next scanner to be initialized.
629 scanner_push (struct scanner *scanner, enum segment_type type,
630 struct substring s, struct token *token)
632 switch (scanner->state)
635 return scan_start__ (scanner, type, s, token);
638 return scan_dash__ (type, s, token);
641 return scan_string__ (scanner, type, s, token);
647 /* Initializes SLEX for parsing INPUT, which is LENGTH bytes long, in the
650 SLEX has no internal state to free, but it retains a reference to INPUT, so
651 INPUT must not be modified or freed while SLEX is still in use. */
653 string_lexer_init (struct string_lexer *slex, const char *input, size_t length,
654 enum segmenter_mode mode, bool is_snippet)
656 *slex = (struct string_lexer) {
660 .segmenter = segmenter_init (mode, is_snippet),
666 string_lexer_next (struct string_lexer *slex, struct token *token)
668 struct segmenter saved_segmenter;
669 size_t saved_offset = 0;
671 struct scanner scanner;
673 scanner_init (&scanner, token);
676 const char *s = slex->input + slex->offset;
677 size_t left = slex->length - slex->offset;
678 enum segment_type type;
681 n = segmenter_push (&slex->segmenter, s, left, true, &type);
685 switch (scanner_push (&scanner, type, ss_buffer (s, n), token))
688 slex->segmenter = saved_segmenter;
689 slex->offset = saved_offset;
692 return token->type != T_STOP;
698 saved_segmenter = slex->segmenter;
699 saved_offset = slex->offset;