ast.c

   1 /*
   2  * Copyright (C) 2013-2014 Jo-Philipp Wich <jow@openwrt.org>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include "ast.h"
  18 #include "lexer.h"
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <stdarg.h>
  23 #include <string.h>
  24 #include <libubox/utils.h>
  25
  26 struct jp_opcode *
  27 jp_alloc_op(struct jp_state *s, int type, int num, char *str, ...)
  28 {
  29         va_list ap;
  30         char *ptr;
  31         struct jp_opcode *newop, *child;
  32
  33         newop = calloc_a(sizeof(*newop),
  34                          str ? &ptr : NULL, str ? strlen(str) + 1 : 0);
  35
  36         if (!newop)
  37         {
  38                 fprintf(stderr, "Out of memory\n");
  39                 exit(127);
  40         }
  41
  42         newop->type = type;
  43         newop->num = num;
  44
  45         if (str)
  46                 newop->str = strcpy(ptr, str);
  47
  48         va_start(ap, str);
  49
  50         while ((child = va_arg(ap, void *)) != NULL)
  51                 if (!newop->down)
  52                         newop->down = child;
  53                 else
  54                         append_op(newop->down, child);
  55
  56         va_end(ap);
  57
  58         newop->next = s->pool;
  59         s->pool = newop;
  60
  61         return newop;
  62 }
  63
  64 void
  65 jp_free(struct jp_state *s)
  66 {
  67         struct jp_opcode *op, *tmp;
  68
  69         for (op = s->pool; op;)
  70         {
  71                 tmp = op->next;
  72                 free(op);
  73                 op = tmp;
  74         }
  75
  76         if (s->error)
  77                 free(s->error);
  78
  79         free(s);
  80 }
  81
  82 struct jp_state *
  83 jp_parse(const char *expr)
  84 {
  85         struct jp_state *s;
  86         struct jp_opcode *op;
  87         const char *ptr = expr;
  88         void *pParser;
  89         int len = strlen(expr);
  90         int mlen = 0;
  91
  92         s = calloc(1, sizeof(*s));
  93
  94         if (!s)
  95                 return NULL;
  96
  97         pParser = ParseAlloc(malloc);
  98
  99         if (!pParser)
 100                 return NULL;
 101
 102         while (len > 0)
 103         {
 104                 s->off = (ptr - expr);
 105
 106                 op = jp_get_token(s, ptr, &mlen);
 107
 108                 if (mlen < 0)
 109                 {
 110                         s->erroff = s->off;
 111                         s->error = strdup((mlen == -3) ? "String too long" :
 112                                                                 (mlen == -2) ? "Invalid escape sequence" :
 113                                                                         (mlen == -1) ? "Unterminated string" :
 114                                                                                 "Unknown error");
 115
 116                         goto out;
 117                 }
 118
 119                 if (op)
 120                         Parse(pParser, op->type, op, s);
 121
 122                 len -= mlen;
 123                 ptr += mlen;
 124         }
 125
 126         Parse(pParser, 0, NULL, s);
 127
 128 out:
 129         ParseFree(pParser, free);
 130
 131         return s;
 132 }