1/*
2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15#include <vlib/vlib.h>
16#include <vlib/lex.h>
17
18vlib_lex_main_t vlib_lex_main;
19
20#define LEX_DEBUG 0
21
22u8 *
23format_vlib_lex_token (u8 * s, va_list * args)
24{
25  vlib_lex_main_t *lm = va_arg (*args, vlib_lex_main_t *);
26  vlib_lex_token_t *t = va_arg (*args, vlib_lex_token_t *);
27
28  if (t->token == VLIB_LEX_word)
29    s = format (s, "%s", t->value.as_pointer);
30  else
31    s = format (s, "%s", lm->lex_token_names[t->token]);
32  return s;
33}
34
35void
36vlib_lex_get_token (vlib_lex_main_t * lm, vlib_lex_token_t * rv)
37{
38  u8 c;
39  vlib_lex_table_t *t;
40  vlib_lex_table_entry_t *e;
41  uword tv;
42
43  if (PREDICT_FALSE (lm->pushback_sp >= 0))
44    {
45      rv[0] = lm->pushback_vector[lm->pushback_sp--];
46      return;
47    }
48
49  rv->value.as_uword = ~0;
50
51  while (1)
52    {
53      if (PREDICT_FALSE (lm->current_index >= vec_len (lm->input_vector)))
54	{
55	  rv->token = VLIB_LEX_eof;
56	  return;
57	}
58
59      t = vec_elt_at_index (lm->lex_tables, lm->current_table_index);
60      c = (lm->input_vector[lm->current_index++]) & 0x7f;
61      e = &t->entries[c];
62      lm->current_table_index = e->next_table_index;
63
64      switch (e->action)
65	{
66	case VLIB_LEX_IGNORE:
67	  continue;
68
69	case VLIB_LEX_START_NUMBER:
70	  lm->current_token_value = 0;
71	  /* fallthru */
72
73	case VLIB_LEX_ADD_TO_NUMBER:
74	  lm->current_number_base = e->token;
75	  lm->current_token_value *= lm->current_number_base;
76	  tv = c - '0';
77	  if (tv >= lm->current_number_base)
78	    {
79	      tv = 10 + c - 'A';
80	      if (tv >= lm->current_number_base)
81		tv = 10 + c - 'a';
82	    }
83	  lm->current_token_value += tv;
84	  continue;
85
86	case VLIB_LEX_ADD_TO_TOKEN:
87	  vec_add1 (lm->token_buffer, c);
88	  continue;
89
90	case VLIB_LEX_KEYWORD_CHECK:
91	  {
92	    uword *p;
93
94	    vec_add1 (lm->token_buffer, 0);
95
96	    /* It's either a keyword or just a word. */
97	    p = hash_get_mem (lm->lex_keywords, lm->token_buffer);
98	    if (p)
99	      {
100		rv->token = p[0];
101		if (LEX_DEBUG > 0)
102		  clib_warning ("keyword '%s' token %s",
103				lm->token_buffer,
104				lm->lex_token_names[rv->token]);
105	      }
106	    else
107	      {
108		/* it's a WORD */
109		rv->token = VLIB_LEX_word;
110		rv->value.as_pointer = vec_dup (lm->token_buffer);
111		if (LEX_DEBUG > 0)
112		  clib_warning ("%s, value '%s'",
113				lm->lex_token_names[VLIB_LEX_word],
114				rv->value.as_pointer);
115	      }
116	    _vec_len (lm->token_buffer) = 0;
117
118	    /* Rescan the character which terminated the keyword/word. */
119	    lm->current_index--;
120	    return;
121	  }
122
123	case VLIB_LEX_RETURN_AND_RESCAN:
124	  ASSERT (lm->current_index);
125	  lm->current_index--;
126	  /* note flow-through */
127
128	case VLIB_LEX_RETURN:
129	  rv->token = e->token;
130	  rv->value.as_uword = lm->current_token_value;
131	  lm->current_token_value = ~0;
132	  if (LEX_DEBUG > 0)
133	    {
134	      clib_warning
135		("table %s char '%c'(0x%02x) next table %s return %s",
136		 t->name, c, c, lm->lex_tables[e->next_table_index].name,
137		 lm->lex_token_names[e->token]);
138	      if (rv->token == VLIB_LEX_number)
139		clib_warning ("  numeric value 0x%x (%d)", rv->value,
140			      rv->value);
141	    }
142	  return;
143	}
144    }
145}
146
147u16
148vlib_lex_add_token (vlib_lex_main_t * lm, char *token_name)
149{
150  uword *p;
151  u16 rv;
152
153  p = hash_get_mem (lm->lex_tokens_by_name, token_name);
154
155  if (p)
156    return p[0];
157
158  rv = vec_len (lm->lex_token_names);
159  hash_set_mem (lm->lex_tokens_by_name, token_name, rv);
160  vec_add1 (lm->lex_token_names, token_name);
161
162  return rv;
163}
164
165static u16
166add_keyword (vlib_lex_main_t * lm, char *keyword, char *token_name)
167{
168  uword *p;
169  u16 token;
170
171  p = hash_get_mem (lm->lex_keywords, keyword);
172
173  ASSERT (p == 0);
174
175  token = vlib_lex_add_token (lm, token_name);
176
177  hash_set_mem (lm->lex_keywords, keyword, token);
178  return token;
179}
180
181u16
182vlib_lex_find_or_add_keyword (vlib_lex_main_t * lm, char *keyword,
183			      char *token_name)
184{
185  uword *p = hash_get_mem (lm->lex_keywords, keyword);
186  return p ? p[0] : add_keyword (lm, keyword, token_name);
187}
188
189void
190vlib_lex_set_action_range (u32 table_index, u8 lo, u8 hi, u16 action,
191			   u16 token, u32 next_table_index)
192{
193  int i;
194  vlib_lex_main_t *lm = &vlib_lex_main;
195  vlib_lex_table_t *t = pool_elt_at_index (lm->lex_tables, table_index);
196
197  for (i = lo; i <= hi; i++)
198    {
199      ASSERT (i < ARRAY_LEN (t->entries));
200      t->entries[i].action = action;
201      t->entries[i].token = token;
202      t->entries[i].next_table_index = next_table_index;
203    }
204}
205
206u16
207vlib_lex_add_table (char *name)
208{
209  vlib_lex_main_t *lm = &vlib_lex_main;
210  vlib_lex_table_t *t;
211  uword *p;
212
213  p = hash_get_mem (lm->lex_tables_by_name, name);
214
215  ASSERT (p == 0);
216
217  pool_get_aligned (lm->lex_tables, t, CLIB_CACHE_LINE_BYTES);
218
219  t->name = name;
220
221  hash_set_mem (lm->lex_tables_by_name, name, t - lm->lex_tables);
222
223  vlib_lex_set_action_range (t - lm->lex_tables, 1, 0x7F, VLIB_LEX_IGNORE, ~0,
224			     t - lm->lex_tables);
225
226  vlib_lex_set_action_range (t - lm->lex_tables, 0, 0, VLIB_LEX_RETURN,
227			     VLIB_LEX_eof, t - lm->lex_tables);
228
229  return t - lm->lex_tables;
230}
231
232void
233vlib_lex_reset (vlib_lex_main_t * lm, u8 * input_vector)
234{
235  if (lm->pushback_vector)
236    _vec_len (lm->pushback_vector) = 0;
237  lm->pushback_sp = -1;
238
239  lm->input_vector = input_vector;
240  lm->current_index = 0;
241}
242
243static clib_error_t *
244lex_onetime_init (vlib_main_t * vm)
245{
246  vlib_lex_main_t *lm = &vlib_lex_main;
247
248  lm->lex_tables_by_name = hash_create_string (0, sizeof (uword));
249  lm->lex_tokens_by_name = hash_create_string (0, sizeof (uword));
250  lm->lex_keywords = hash_create_string (0, sizeof (uword));
251  lm->pushback_sp = -1;
252
253#define _(f) { u16 tmp = vlib_lex_add_token (lm, #f); ASSERT (tmp == VLIB_LEX_##f); }
254  foreach_vlib_lex_global_token;
255#undef _
256
257  vec_validate (lm->token_buffer, 127);
258  _vec_len (lm->token_buffer) = 0;
259
260  return 0;
261}
262
263VLIB_INIT_FUNCTION (lex_onetime_init);
264
265/*
266 * fd.io coding-style-patch-verification: ON
267 *
268 * Local Variables:
269 * eval: (c-set-style "gnu")
270 * End:
271 */
272