Lexical analyser.

1 files changed, 217 insertions, 0 deletions

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
new file mode 100644
index 0000000..5509fae
--- /dev/null
+++ b/conf/cf-lex.l
@@ -0,0 +1,217 @@
+/*
+ *	BIRD -- Configuration Lexer
+ *
+ *	(c) 1998 Martin Mares <mj@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+%{
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "nest/bird.h"
+#include "conf/conf.h"
+#include "conf/cf-parse.tab.h"
+
+static struct keyword {
+  byte *name;
+  int value;
+  struct keyword *next;
+} keyword_list[] = {
+#include "keywords.h"
+  { NULL, -1 } };
+
+#define KW_HASH_SIZE 64
+#define SYM_HASH_SIZE 128
+#define SYM_MAX_LEN 32
+
+static struct keyword *kw_hash[KW_HASH_SIZE];
+static struct symbol **sym_hash;
+static int allow_new_symbols;
+static int cf_lino;
+
+static int cf_hash(byte *c);
+static struct symbol *cf_find_sym(byte *c, unsigned int h0);
+
+pool *cfg_pool;
+mempool *cfg_mem;
+
+int (*cf_read_hook)(byte *buf, unsigned int max);
+
+#define YY_INPUT(buf,result,max) result = cf_read_hook(buf, max);
+#define YY_NO_UNPUT
+#define YY_FATAL_ERROR(msg) cf_error(msg)
+
+%}
+
+%option noyywrap
+
+%x COMMENT CCOMM
+
+ALPHA [a-zA-Z_]
+DIGIT [0-9]
+XIGIT [0-9a-fA-F]
+ALNUM [a-zA-Z_0-9]
+WHITE [ \t]
+
+%%
+
+{DIGIT}+\.{DIGIT}+\.{DIGIT}+\.{DIGIT}+ {
+  if (ip_pton(yytext, &cf_lval.a))
+    return IPA;
+  cf_error("Invalid IP address");
+}
+
+0x{DIGIT}+ {
+  char *e;
+  long int l;
+  errno = 0;
+  l = strtoul(yytext+2, &e, 16);
+  if (e && *e || errno == ERANGE || (long int)(int) l != l)
+    cf_error("Number out of range");
+  cf_lval.i = l;
+  return NUM;
+}
+
+{DIGIT}+ {
+  char *e;
+  long int l;
+  errno = 0;
+  l = strtoul(yytext, &e, 10);
+  if (e && *e || errno == ERANGE || (long int)(int) l != l)
+    cf_error("Number out of range");
+  cf_lval.i = l;
+  return NUM;
+}
+
+{ALPHA}{ALNUM}* {
+  unsigned int h = cf_hash(yytext);
+  struct keyword *k = kw_hash[h & (KW_HASH_SIZE-1)];
+  while (k)
+    {
+      if (!strcmp(k->name, yytext))
+	return k->value;
+      k=k->next;
+    }
+  cf_lval.s = cf_find_sym(yytext, h);
+  return SYM;
+}
+
+[{}:;,] {
+  return yytext[0];
+}
+
+["][^"\n]*["] {
+  cf_lval.t = yytext+1;
+  yytext[yyleng] = 0;
+  return TEXT;
+}
+
+["][^"\n]*\n	cf_error("Unterminated string");
+
+<INITIAL,COMMENT><<EOF>>	return END;
+
+{WHITE}+
+
+\\\n {
+  cf_lino++;
+}
+
+\n {
+  cf_lino++;
+  return ';';
+}
+
+#	{ BEGIN(COMMENT); }
+
+\/\*	{ BEGIN(CCOMM); }
+
+.	cf_error("Unknown character");
+
+<COMMENT>\n {
+  cf_lino++;
+  BEGIN(INITIAL);
+}
+
+<COMMENT>.
+
+<CCOMM>\*\/	BEGIN(INITIAL);
+<CCOMM>\n	cf_lino++;
+<CCOMM>\/\*	cf_error("Comment nesting not supported");
+<CCOMM><<EOF>>	cf_error("Unterminated comment");
+<CCOMM>.
+
+%%
+
+static int
+cf_hash(byte *c)
+{
+  unsigned int h = 13;
+
+  while (*c)
+    h = (h * 37) + *c++;
+  return h;
+}
+
+static struct symbol *
+cf_find_sym(byte *c, unsigned int h0)
+{
+  unsigned int h = h0 & (SYM_HASH_SIZE-1);
+  struct symbol *s = sym_hash[h];
+  int l;
+
+  while (s)
+    if (!strcmp(s->name, c))
+      return s;
+  if (!allow_new_symbols)
+    return NULL;
+  l = strlen(c);
+  if (l > SYM_MAX_LEN)
+    cf_error("Symbol too long");
+  s = mp_alloc(cfg_mem, sizeof(struct symbol) + l);
+  s->next = sym_hash[h];
+  sym_hash[h] = s;
+  s->class = SYM_VOID;
+  s->def = NULL;
+  strcpy(s->name, c);
+  return s;
+}
+
+void
+cf_lex_init(int flag)
+{
+  if (allow_new_symbols = flag)
+    sym_hash = mp_allocz(cfg_mem, SYM_HASH_SIZE * sizeof(struct keyword *));
+  cf_lino = 1;
+}
+
+void
+cf_lex_init_tables(void)
+{
+  struct keyword *k;
+
+  for(k=keyword_list; k->name; k++)
+    {
+      unsigned h = cf_hash(k->name) & (KW_HASH_SIZE-1);
+      k->next = kw_hash[h];
+      kw_hash[h] = k;
+    }
+}
+
+void
+cf_error(char *msg)
+{
+  die(PATH_CONFIG ", line %d: %s", cf_lino, msg);
+}
+
+void
+cf_allocate(void)
+{
+  if (cfg_pool)
+    rfree(cfg_pool);
+  cfg_pool = rp_new(&root_pool, "Config");
+  cfg_mem = mp_new(cfg_pool, 1024);
+}