Switch to sqlite3's lemon parser generator.

[project/jsonpath.git] / ast.c

diff --git a/ast.c b/ast.c
new file mode 100644 (file)
index 0000000..5093e8b
--- /dev/null
+++ b/ast.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2013-2014 Jo-Philipp Wich <jow@openwrt.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ast.h"
+#include "lexer.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <libubox/utils.h>
+
+struct jp_opcode *
+jp_alloc_op(struct jp_state *s, int type, int num, char *str, ...)
+{
+       va_list ap;
+       char *ptr;
+       struct jp_opcode *newop, *child;
+
+       newop = calloc_a(sizeof(*newop),
+                        str ? &ptr : NULL, str ? strlen(str) + 1 : 0);
+
+       if (!newop)
+       {
+               fprintf(stderr, "Out of memory\n");
+               exit(127);
+       }
+
+       newop->type = type;
+       newop->num = num;
+
+       if (str)
+               newop->str = strcpy(ptr, str);
+
+       va_start(ap, str);
+
+       while ((child = va_arg(ap, void *)) != NULL)
+               if (!newop->down)
+                       newop->down = child;
+               else
+                       append_op(newop->down, child);
+
+       va_end(ap);
+
+       newop->next = s->pool;
+       s->pool = newop;
+
+       return newop;
+}
+
+void
+jp_free(struct jp_state *s)
+{
+       struct jp_opcode *op, *tmp;
+
+       for (op = s->pool; op;)
+       {
+               tmp = op->next;
+               free(op);
+               op = tmp;
+       }
+
+       if (s->error)
+               free(s->error);
+
+       free(s);
+}
+
+struct jp_state *
+jp_parse(const char *expr)
+{
+       struct jp_state *s;
+       struct jp_opcode *op;
+       const char *ptr = expr;
+       void *pParser;
+       int len = strlen(expr);
+       int mlen = 0;
+
+       s = calloc(1, sizeof(*s));
+
+       if (!s)
+               return NULL;
+
+       pParser = ParseAlloc(malloc);
+
+       if (!pParser)
+               return NULL;
+
+       while (len > 0)
+       {
+               s->off = (ptr - expr);
+
+               op = jp_get_token(s, ptr, &mlen);
+
+               if (mlen < 0)
+               {
+                       s->erroff = s->off;
+                       s->error = strdup((mlen == -3) ? "String too long" :
+                                                               (mlen == -2) ? "Invalid escape sequence" :
+                                                                       (mlen == -1) ? "Unterminated string" :
+                                                                               "Unknown error");
+
+                       goto out;
+               }
+
+               if (op)
+                       Parse(pParser, op->type, op, s);
+
+               len -= mlen;
+               ptr += mlen;
+       }
+
+       Parse(pParser, 0, NULL, s);
+
+out:
+       ParseFree(pParser, free);
+
+       return s;
+}