/* macros.c - a simple macro expander Copyright (c) 2010, 2014 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include static inline int macro_isalnum (i8 c) { if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || (c == '_')) return 1; return 0; } static i8 * builtin_eval (macro_main_t * mm, i8 * varname, i32 complain) { uword *p; i8 *(*fp) (macro_main_t *, i32); p = hash_get_mem (mm->the_builtin_eval_hash, varname); if (p == 0) return 0; fp = (void *) (p[0]); return (*fp) (mm, complain); } int clib_macro_unset (macro_main_t * mm, char *name) { hash_pair_t *p; u8 *key, *value; p = hash_get_pair (mm->the_value_table_hash, name); if (p == 0) return 1; key = (u8 *) (p->key); value = (u8 *) (p->value[0]); hash_unset_mem (mm->the_value_table_hash, name); vec_free (value); vec_free (key); return 0; } int clib_macro_set_value (macro_main_t * mm, char *name, char *value) { u8 *key_copy, *value_copy; int rv; rv = clib_macro_unset (mm, name); key_copy = format (0, "%s%c", name, 0); value_copy = format (0, "%s%c", value, 0); hash_set_mem (mm->the_value_table_hash, key_copy, value_copy); return rv; } i8 * clib_macro_get_value (macro_main_t * mm, char *name) { uword *p; p = hash_get_mem (mm->the_value_table_hash, name); if (p) return (i8 *) (p[0]); else return 0; } /* * eval: takes a string, returns a vector. * looks up $foobar in the variable table. */ i8 * clib_macro_eval (macro_main_t * mm, i8 * s, i32 complain) { i8 *rv = 0; i8 *varname, *varvalue; i8 *ts; while (*s) { switch (*s) { case '\\': s++; /* fallthrough */ default: vec_add1 (rv, *s); s++; break; case '$': s++; varname = 0; /* * Make vector with variable name in it. */ while (*s && (macro_isalnum (*s) || (*s == '_') || (*s == '('))) { /* handle $(foo) */ if (*s == '(') { s++; /* skip '(' */ while (*s && *s != ')') { vec_add1 (varname, *s); s++; } if (*s) s++; /* skip ')' */ break; } vec_add1 (varname, *s); s++; } /* null terminate */ vec_add1 (varname, 0); /* Look for a builtin, e.g. $my_hostname */ if (!(varvalue = builtin_eval (mm, varname, complain))) { /* Look in value table */ if (!varvalue) { char *tmp = clib_macro_get_value (mm, varname); if (tmp) varvalue = (i8 *) format (0, "%s%c", tmp, 0); } #ifdef CLIB_UNIX /* Look in environment. */ if (!varvalue) { char *tmp = getenv (varname); if (tmp) varvalue = (i8 *) format (0, "%s%c", tmp, 0); } #endif /* CLIB_UNIX */ } if (varvalue) { /* recursively evaluate */ ts = clib_macro_eval (mm, varvalue, complain); vec_free (varvalue); /* add results to answer */ vec_append (rv, ts); /* Remove NULL termination or the results are sad */ _vec_len (rv) = vec_len (rv) - 1; vec_free (ts); } else { if (complain) clib_warning ("Undefined Variable Reference: %s\n", varname); vec_append (rv, format (0, "UNSET ")); _vec_len (rv) = vec_len (rv) - 1; } vec_free (varname); } } vec_add1 (rv, 0); return (rv); } /* * eval: takes a string, returns a vector. * looks up $foobar in the variable table. */ i8 * clib_macro_eval_dollar (macro_main_t * mm, i8 * s, i32 complain) { i8 *s2; i8 *rv; s2 = (i8 *) format (0, "$(%s)%c", s, 0); rv = clib_macro_eval (mm, s2, complain); vec_free (s2); return (rv); } void clib_macro_add_builtin (macro_main_t * mm, char *name, void *eval_fn) { hash_set_mem (mm->the_builtin_eval_hash, name, (uword) eval_fn); } #ifdef CLIB_UNIX static i8 * eval_hostname (macro_main_t * mm, i32 complain) { char tmp[128]; if (gethostname (tmp, sizeof (tmp))) return ((i8 *) format (0, "gethostname-error%c", 0)); return ((i8 *) format (0, "%s%c", tmp, 0)); } #endif void clib_macro_init (macro_main_t * mm) { if (mm->the_builtin_eval_hash != 0) { clib_warning ("mm %p already initialized", mm); return; } mm->the_builtin_eval_hash = hash_create_string (0, sizeof (uword)); mm->the_value_table_hash = hash_create_string (0, sizeof (uword)); #ifdef CLIB_UNIX hash_set_mem (mm->the_builtin_eval_hash, "hostname", (uword) eval_hostname); #endif } void clib_macro_free (macro_main_t * mm) { hash_pair_t *p; u8 **strings_to_free = 0; int i; hash_free (mm->the_builtin_eval_hash); /* *INDENT-OFF* */ hash_foreach_pair (p, mm->the_value_table_hash, ({ vec_add1 (strings_to_free, (u8 *) (p->key)); vec_add1 (strings_to_free, (u8 *) (p->value[0])); })); /* *INDENT-ON* */ for (i = 0; i < vec_len (strings_to_free); i++) vec_free (strings_to_free[i]); vec_free (strings_to_free); hash_free (mm->the_value_table_hash); } /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */