diff options
Diffstat (limited to 'contrib/snowball/compiler/tokeniser.c')
-rw-r--r-- | contrib/snowball/compiler/tokeniser.c | 470 |
1 files changed, 470 insertions, 0 deletions
diff --git a/contrib/snowball/compiler/tokeniser.c b/contrib/snowball/compiler/tokeniser.c new file mode 100644 index 000000000..3dae5f744 --- /dev/null +++ b/contrib/snowball/compiler/tokeniser.c @@ -0,0 +1,470 @@ + +#include <stdio.h> /* stderr etc */ +#include <stdlib.h> /* malloc free */ +#include <string.h> /* strlen */ +#include <ctype.h> /* isalpha etc */ +#include "header.h" + +struct system_word { + int s_size; /* size of system word */ + const byte * s; /* pointer to the system word */ + int code; /* its internal code */ +}; + + +/* ASCII collating assumed in syswords.c */ + +#include "syswords.h" + +static int smaller(int a, int b) { return a < b ? a : b; } + +extern symbol * get_input(symbol * p, char ** p_file) { + + char * s = b_to_s(p); + { + FILE * input = fopen(s, "r"); + if (input == 0) { free(s); return 0; } + *p_file = s; + { + symbol * u = create_b(STARTSIZE); + int size = 0; + repeat + { int ch = getc(input); + if (ch == EOF) break; + if (size >= CAPACITY(u)) u = increase_capacity(u, size/2); + u[size++] = ch; + } + fclose(input); + SIZE(u) = size; return u; + } + } +} + +static void error(struct tokeniser * t, char * s1, int n, symbol * p, char * s2) { + if (t->error_count == 20) { fprintf(stderr, "... etc\n"); exit(1); } + fprintf(stderr, "%s:%d: ", t->file, t->line_number); + unless (s1 == 0) fprintf(stderr, "%s", s1); + unless (p == 0) { + int i; + for (i = 0; i < n; i++) fprintf(stderr, "%c", p[i]); + } + unless (s2 == 0) fprintf(stderr, "%s", s2); + fprintf(stderr, "\n"); + t->error_count++; +} + +static void error1(struct tokeniser * t, char * s) { + error(t, s, 0,0, 0); +} + +static void error2(struct tokeniser * t, char * s) { + error(t, "unexpected end of text after ", 0,0, s); +} + +static int compare_words(int m, symbol * p, int n, const byte * q) { + unless (m == n) return m - n; + { + int i; for (i = 0; i < n; i++) { + int diff = p[i] - q[i]; + unless (diff == 0) return diff; + } + } + return 0; +} + +static int find_word(int n, symbol * p) { + int i = 0; int j = vocab->code; + repeat { + int k = i + (j - i)/2; + const struct system_word * w = vocab + k; + int diff = compare_words(n, p, w->s_size, w->s); + if (diff == 0) return w->code; + if (diff < 0) j = k; else i = k; + if (j - i == 1) break; + } + return -1; +} + +static int get_number(int n, symbol * p) { + int x = 0; + int i; for (i = 0; i < n; i++) x = 10*x + p[i] - '0'; + return x; +} + +static int eq_s(struct tokeniser * t, char * s) { + int l = strlen(s); + if (SIZE(t->p) - t->c < l) return false; + { + int i; + for (i = 0; i < l; i++) if (t->p[t->c + i] != s[i]) return false; + } + t->c += l; return true; +} + +static int white_space(struct tokeniser * t, int ch) { + switch (ch) { + case '\n': t->line_number++; + case '\r': + case '\t': + case ' ': return true; + } + return false; +} + +static symbol * find_in_m(struct tokeniser * t, int n, symbol * p) { + struct m_pair * q = t->m_pairs; + repeat { + if (q == 0) return 0; + { + symbol * name = q->name; + if (n == SIZE(name) && memcmp(name, p, n * sizeof(symbol)) == 0) return q->value; + } + q = q->next; + } +} + +static int read_literal_string(struct tokeniser * t, int c) { + symbol * p = t->p; + int ch; + SIZE(t->b) = 0; + repeat { + if (c >= SIZE(p)) { error2(t, "'"); return c; } + ch = p[c]; + if (ch == '\n') { error1(t, "string not terminated"); return c; } + c++; + if (ch == t->m_start) { + int c0 = c; + int newlines = false; /* no newlines as yet */ + int black_found = false; /* no printing chars as yet */ + repeat { + if (c >= SIZE(p)) { error2(t, "'"); return c; } + ch = p[c]; c++; + if (ch == t->m_end) break; + unless (white_space(t, ch)) black_found = true; + if (ch == '\n') newlines = true; + if (newlines && black_found) { + error1(t, "string not terminated"); + return c; + } + } + unless (newlines) { + int n = c - c0 - 1; /* macro size */ + int firstch = p[c0]; + symbol * q = find_in_m(t, n, p + c0); + if (q == 0) { + if (n == 1 && (firstch == '\'' || firstch == t->m_start)) + t->b = add_to_b(t->b, 1, p + c0); + else + error(t, "string macro '", n, p + c0, "' undeclared"); + } else + t->b = add_to_b(t->b, SIZE(q), q); + } + } else { + if (ch == '\'') return c; + t->b = add_to_b(t->b, 1, p + c - 1); + } + } +} + +static int next_token(struct tokeniser * t) { + symbol * p = t->p; + int c = t->c; + int ch; + int code = -1; + repeat { + if (c >= SIZE(p)) { t->c = c; return -1; } + ch = p[c]; + if (white_space(t, ch)) { c++; continue; } + if (isalpha(ch)) { + int c0 = c; + while (c < SIZE(p) && (isalnum(p[c]) || p[c] == '_')) c++; + code = find_word(c - c0, p + c0); + if (code < 0) { + t->b = move_to_b(t->b, c - c0, p + c0); + code = c_name; + } + } else + if (isdigit(ch)) { + int c0 = c; + while (c < SIZE(p) && isdigit(p[c])) c++; + t->number = get_number(c - c0, p + c0); + code = c_number; + } else + if (ch == '\'') { + c = read_literal_string(t, c + 1); + code = c_literalstring; + } else + { + int lim = smaller(2, SIZE(p) - c); + int i; + for (i = lim; i > 0; i--) { + code = find_word(i, p + c); + if (code >= 0) { c += i; break; } + } + } + if (code >= 0) { + t->c = c; + return code; + } + error(t, "'", 1, p + c, "' unknown"); + c++; + continue; + } +} + +static int next_char(struct tokeniser * t) { + if (t->c >= SIZE(t->p)) return -1; + return t->p[t->c++]; +} + +static int next_real_char(struct tokeniser * t) { + repeat { + int ch = next_char(t); + if (white_space(t, ch)) continue; + return ch; + } +} + +static void read_chars(struct tokeniser * t) { + int ch = next_real_char(t); + if (ch < 0) { error2(t, "stringdef"); return; } + { + int c0 = t->c-1; + repeat { + ch = next_char(t); + if (white_space(t, ch) || ch < 0) break; + } + t->b2 = move_to_b(t->b2, t->c - c0 - 1, t->p + c0); + } +} + +static int decimal_to_num(int ch) { + if ('0' <= ch && ch <= '9') return ch - '0'; + return -1; +} + +static int hex_to_num(int ch) { + if ('0' <= ch && ch <= '9') return ch - '0'; + if ('a' <= ch && ch <= 'f') return ch - 'a' + 10; + return -1; +} + +static void convert_numeric_string(struct tokeniser * t, symbol * p, int base) { + int c = 0; int d = 0; + repeat { + while (c < SIZE(p) && p[c] == ' ') c++; + if (c == SIZE(p)) break; + { + int number = 0; + repeat { + int ch = p[c]; + if (c == SIZE(p) || ch == ' ') break; + if (base == 10) { + ch = decimal_to_num(ch); + if (ch < 0) { + error1(t, "decimal string contains non-digits"); + return; + } + } else { + ch = hex_to_num(tolower(ch)); + if (ch < 0) { + error1(t, "hex string contains non-hex characters"); + return; + } + } + number = base * number + ch; + c++; + } + if (t->widechars || t->utf8) { + unless (0 <= number && number <= 0xffff) { + error1(t, "character values exceed 64K"); + return; + } + } else { + unless (0 <= number && number <= 0xff) { + error1(t, "character values exceed 256"); + return; + } + } + if (t->utf8) + d += put_utf8(number, p + d); + else + p[d++] = number; + } + } + SIZE(p) = d; +} + +extern int read_token(struct tokeniser * t) { + symbol * p = t->p; + int held = t->token_held; + t->token_held = false; + if (held) return t->token; + repeat { + int code = next_token(t); + switch (code) { + case c_comment1: /* slash-slash comment */ + while (t->c < SIZE(p) && p[t->c] != '\n') t->c++; + continue; + case c_comment2: /* slash-star comment */ + repeat { + if (t->c >= SIZE(p)) { + error1(t, "/* comment not terminated"); + t->token = -1; + return -1; + } + if (p[t->c] == '\n') t->line_number++; + if (eq_s(t, "*/")) break; + t->c++; + } + continue; + case c_stringescapes: + { + int ch1 = next_real_char(t); + int ch2 = next_real_char(t); + if (ch2 < 0) + { error2(t, "stringescapes"); continue; } + if (ch1 == '\'') + { error1(t, "first stringescape cannot be '"); continue; } + t->m_start = ch1; + t->m_end = ch2; + } + continue; + case c_stringdef: + { + int base = 0; + read_chars(t); + code = read_token(t); + if (code == c_hex) { base = 16; code = read_token(t); } else + if (code == c_decimal) { base = 10; code = read_token(t); } + unless (code == c_literalstring) + { error1(t, "string omitted after stringdef"); continue; } + if (base > 0) convert_numeric_string(t, t->b, base); + { NEW(m_pair, q); + q->next = t->m_pairs; + q->name = copy_b(t->b2); + q->value = copy_b(t->b); + t->m_pairs = q; + } + } + continue; + case c_get: + code = read_token(t); + unless (code == c_literalstring) { + error1(t, "string omitted after get"); continue; + } + t->get_depth++; + if (t->get_depth > 10) { + fprintf(stderr, "get directives go 10 deep. Looping?\n"); + exit(1); + } + { + char * file; + NEW(input, q); + symbol * u = get_input(t->b, &file); + if (u == 0) { + struct include * r = t->includes; + until (r == 0) { + symbol * b = copy_b(r->b); + b = add_to_b(b, SIZE(t->b), t->b); + u = get_input(b, &file); + lose_b(b); + unless (u == 0) break; + r = r->next; + } + } + if (u == 0) { + error(t, "Can't get '", SIZE(t->b), t->b, "'"); + exit(1); + } + memmove(q, t, sizeof(struct input)); + t->next = q; + t->p = u; + t->c = 0; + t->file = file; + t->line_number = 1; + } + p = t->p; + continue; + case -1: + unless (t->next == 0) { + lose_b(p); + { + struct input * q = t->next; + memmove(t, q, sizeof(struct input)); p = t->p; + FREE(q); + } + t->get_depth--; + continue; + } + /* drop through */ + default: + t->previous_token = t->token; + t->token = code; + return code; + } + } +} + +extern const char * name_of_token(int code) { + int i; + for (i = 1; i < vocab->code; i++) + if ((vocab + i)->code == code) return (const char *)(vocab + i)->s; + switch (code) { + case c_mathassign: return "="; + case c_name: return "name"; + case c_number: return "number"; + case c_literalstring:return "literal"; + case c_neg: return "neg"; + case c_grouping: return "grouping"; + case c_call: return "call"; + case c_booltest: return "Boolean test"; + case -2: return "start of text"; + case -1: return "end of text"; + default: return "?"; + } +} + +extern struct tokeniser * create_tokeniser(symbol * p, char * file) { + NEW(tokeniser, t); + t->next = 0; + t->p = p; + t->c = 0; + t->file = file; + t->line_number = 1; + t->b = create_b(0); + t->b2 = create_b(0); + t->m_start = -1; + t->m_pairs = 0; + t->get_depth = 0; + t->error_count = 0; + t->token_held = false; + t->token = -2; + t->previous_token = -2; + return t; +} + +extern void close_tokeniser(struct tokeniser * t) { + lose_b(t->b); + lose_b(t->b2); + { + struct m_pair * q = t->m_pairs; + until (q == 0) { + struct m_pair * q_next = q->next; + lose_b(q->name); + lose_b(q->value); + FREE(q); + q = q_next; + } + } + { + struct input * q = t->next; + until (q == 0) { + struct input * q_next = q->next; + FREE(q); + q = q_next; + } + } + free(t->file); + FREE(t); +} |