Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 1 | /* Grammar implementation */ |
| 2 | |
Guido van Rossum | 3f5da24 | 1990-12-20 15:06:42 +0000 | [diff] [blame^] | 3 | #include "pgenheaders.h" |
| 4 | |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 5 | #include <ctype.h> |
| 6 | |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 7 | #include "assert.h" |
| 8 | #include "token.h" |
| 9 | #include "grammar.h" |
| 10 | |
| 11 | extern int debugging; |
| 12 | |
| 13 | grammar * |
| 14 | newgrammar(start) |
| 15 | int start; |
| 16 | { |
| 17 | grammar *g; |
| 18 | |
| 19 | g = NEW(grammar, 1); |
| 20 | if (g == NULL) |
| 21 | fatal("no mem for new grammar"); |
| 22 | g->g_ndfas = 0; |
| 23 | g->g_dfa = NULL; |
| 24 | g->g_start = start; |
| 25 | g->g_ll.ll_nlabels = 0; |
| 26 | g->g_ll.ll_label = NULL; |
| 27 | return g; |
| 28 | } |
| 29 | |
| 30 | dfa * |
| 31 | adddfa(g, type, name) |
| 32 | grammar *g; |
| 33 | int type; |
| 34 | char *name; |
| 35 | { |
| 36 | dfa *d; |
| 37 | |
| 38 | RESIZE(g->g_dfa, dfa, g->g_ndfas + 1); |
| 39 | if (g->g_dfa == NULL) |
| 40 | fatal("no mem to resize dfa in adddfa"); |
| 41 | d = &g->g_dfa[g->g_ndfas++]; |
| 42 | d->d_type = type; |
| 43 | d->d_name = name; |
| 44 | d->d_nstates = 0; |
| 45 | d->d_state = NULL; |
| 46 | d->d_initial = -1; |
| 47 | d->d_first = NULL; |
| 48 | return d; /* Only use while fresh! */ |
| 49 | } |
| 50 | |
| 51 | int |
| 52 | addstate(d) |
| 53 | dfa *d; |
| 54 | { |
| 55 | state *s; |
| 56 | |
| 57 | RESIZE(d->d_state, state, d->d_nstates + 1); |
| 58 | if (d->d_state == NULL) |
| 59 | fatal("no mem to resize state in addstate"); |
| 60 | s = &d->d_state[d->d_nstates++]; |
| 61 | s->s_narcs = 0; |
| 62 | s->s_arc = NULL; |
| 63 | return s - d->d_state; |
| 64 | } |
| 65 | |
| 66 | void |
| 67 | addarc(d, from, to, lbl) |
| 68 | dfa *d; |
| 69 | int lbl; |
| 70 | { |
| 71 | state *s; |
| 72 | arc *a; |
| 73 | |
| 74 | assert(0 <= from && from < d->d_nstates); |
| 75 | assert(0 <= to && to < d->d_nstates); |
| 76 | |
| 77 | s = &d->d_state[from]; |
| 78 | RESIZE(s->s_arc, arc, s->s_narcs + 1); |
| 79 | if (s->s_arc == NULL) |
| 80 | fatal("no mem to resize arc list in addarc"); |
| 81 | a = &s->s_arc[s->s_narcs++]; |
| 82 | a->a_lbl = lbl; |
| 83 | a->a_arrow = to; |
| 84 | } |
| 85 | |
| 86 | int |
| 87 | addlabel(ll, type, str) |
| 88 | labellist *ll; |
| 89 | int type; |
| 90 | char *str; |
| 91 | { |
| 92 | int i; |
| 93 | label *lb; |
| 94 | |
| 95 | for (i = 0; i < ll->ll_nlabels; i++) { |
| 96 | if (ll->ll_label[i].lb_type == type && |
| 97 | strcmp(ll->ll_label[i].lb_str, str) == 0) |
| 98 | return i; |
| 99 | } |
| 100 | RESIZE(ll->ll_label, label, ll->ll_nlabels + 1); |
| 101 | if (ll->ll_label == NULL) |
| 102 | fatal("no mem to resize labellist in addlabel"); |
| 103 | lb = &ll->ll_label[ll->ll_nlabels++]; |
| 104 | lb->lb_type = type; |
| 105 | lb->lb_str = str; /* XXX strdup(str) ??? */ |
| 106 | return lb - ll->ll_label; |
| 107 | } |
| 108 | |
| 109 | /* Same, but rather dies than adds */ |
| 110 | |
| 111 | int |
| 112 | findlabel(ll, type, str) |
| 113 | labellist *ll; |
| 114 | int type; |
| 115 | char *str; |
| 116 | { |
| 117 | int i; |
| 118 | label *lb; |
| 119 | |
| 120 | for (i = 0; i < ll->ll_nlabels; i++) { |
| 121 | if (ll->ll_label[i].lb_type == type /*&& |
| 122 | strcmp(ll->ll_label[i].lb_str, str) == 0*/) |
| 123 | return i; |
| 124 | } |
| 125 | fprintf(stderr, "Label %d/'%s' not found\n", type, str); |
| 126 | abort(); |
| 127 | } |
| 128 | |
Guido van Rossum | 3f5da24 | 1990-12-20 15:06:42 +0000 | [diff] [blame^] | 129 | /* Forward */ |
| 130 | static void translabel PROTO((grammar *, label *)); |
| 131 | |
| 132 | void |
| 133 | translatelabels(g) |
| 134 | grammar *g; |
| 135 | { |
| 136 | int i; |
| 137 | |
| 138 | printf("Translating labels ...\n"); |
| 139 | /* Don't translate EMPTY */ |
| 140 | for (i = EMPTY+1; i < g->g_ll.ll_nlabels; i++) |
| 141 | translabel(g, &g->g_ll.ll_label[i]); |
| 142 | } |
| 143 | |
Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 144 | static void |
| 145 | translabel(g, lb) |
| 146 | grammar *g; |
| 147 | label *lb; |
| 148 | { |
| 149 | int i; |
| 150 | |
| 151 | if (debugging) |
| 152 | printf("Translating label %s ...\n", labelrepr(lb)); |
| 153 | |
| 154 | if (lb->lb_type == NAME) { |
| 155 | for (i = 0; i < g->g_ndfas; i++) { |
| 156 | if (strcmp(lb->lb_str, g->g_dfa[i].d_name) == 0) { |
| 157 | if (debugging) |
| 158 | printf("Label %s is non-terminal %d.\n", |
| 159 | lb->lb_str, |
| 160 | g->g_dfa[i].d_type); |
| 161 | lb->lb_type = g->g_dfa[i].d_type; |
| 162 | lb->lb_str = NULL; |
| 163 | return; |
| 164 | } |
| 165 | } |
| 166 | for (i = 0; i < (int)N_TOKENS; i++) { |
| 167 | if (strcmp(lb->lb_str, tok_name[i]) == 0) { |
| 168 | if (debugging) |
| 169 | printf("Label %s is terminal %d.\n", |
| 170 | lb->lb_str, i); |
| 171 | lb->lb_type = i; |
| 172 | lb->lb_str = NULL; |
| 173 | return; |
| 174 | } |
| 175 | } |
| 176 | printf("Can't translate NAME label '%s'\n", lb->lb_str); |
| 177 | return; |
| 178 | } |
| 179 | |
| 180 | if (lb->lb_type == STRING) { |
| 181 | if (isalpha(lb->lb_str[1])) { |
| 182 | char *p, *strchr(); |
| 183 | if (debugging) |
| 184 | printf("Label %s is a keyword\n", lb->lb_str); |
| 185 | lb->lb_type = NAME; |
| 186 | lb->lb_str++; |
| 187 | p = strchr(lb->lb_str, '\''); |
| 188 | if (p) |
| 189 | *p = '\0'; |
| 190 | } |
| 191 | else { |
| 192 | if (lb->lb_str[2] == lb->lb_str[0]) { |
| 193 | int type = (int) tok_1char(lb->lb_str[1]); |
| 194 | if (type != OP) { |
| 195 | lb->lb_type = type; |
| 196 | lb->lb_str = NULL; |
| 197 | } |
| 198 | else |
| 199 | printf("Unknown OP label %s\n", |
| 200 | lb->lb_str); |
| 201 | } |
| 202 | else |
| 203 | printf("Can't translate STRING label %s\n", |
| 204 | lb->lb_str); |
| 205 | } |
| 206 | } |
| 207 | else |
| 208 | printf("Can't translate label '%s'\n", labelrepr(lb)); |
| 209 | } |