From f31ddb36a22e9c99ce4a2c2de14c2265b48d7b27 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Wed, 23 Oct 2013 03:45:57 +0900
Subject: [PATCH] reentrant scanner

---
 src/parse.y | 22 +++++++++++++++++-----
 src/scan.l  | 18 ++++--------------
 2 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/src/parse.y b/src/parse.y
index c2214071..c5363b3c 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -9,15 +9,20 @@
 
 struct parser_control {
   pic_state *pic;
+  void *yyscanner;
   pic_value value;
   bool incomp;
   int yynerrs;
 };
 
-void init_scanner(const char *);
-void final_scanner(void);
-
 void yyerror(struct parser_control *, const char *);
+
+/* just for supressing warnings. a little bit evil */
+int yylex();
+int yylex_();
+void yylex_init();
+void yy_scan_string();
+void yylex_destroy();
 %}
 
 %pure_parser
@@ -122,6 +127,12 @@ yyerror(struct parser_control *p, const char *msg)
   p->yynerrs++;
 }
 
+int
+yylex(YYSTYPE *yylvalp, struct parser_control *p)
+{
+  return yylex_(yylvalp, p->yyscanner, p);
+}
+
 bool
 pic_parse(pic_state *pic, const char *str, pic_value *v)
 {
@@ -131,9 +142,10 @@ pic_parse(pic_state *pic, const char *str, pic_value *v)
   p.incomp = false;
   p.yynerrs = 0;
 
-  init_scanner(str);
+  yylex_init(&p.yyscanner);
+  yy_scan_string(str, p.yyscanner);
   yyparse(&p);
-  final_scanner();
+  yylex_destroy(p.yyscanner);
 
   if (p.yynerrs > 0) {
     p.value = pic_undef_value();
diff --git a/src/scan.l b/src/scan.l
index 3881b3f4..6f8af06b 100644
--- a/src/scan.l
+++ b/src/scan.l
@@ -7,6 +7,7 @@
 
 struct parser_control {
   pic_state *pic;
+  void *yyscanner;
   pic_value value;
   bool incomp;
   int yynerrs;
@@ -14,9 +15,10 @@ struct parser_control {
 
 static pic_value new_escaped_string(pic_state *, const char *);
 
-#define YY_DECL int yylex (YYSTYPE *yylvalp, struct parser_control *p)
+#define YY_DECL int yylex_ (YYSTYPE *yylvalp, yyscan_t yyscanner, struct parser_control *p)
 %}
 
+%option reentrant
 %option noinput
 %option nounput
 
@@ -55,7 +57,7 @@ string_elem	[^\"\\]|"\\\""|"\\\\"
 %%
 
 int
-yywrap()
+yywrap(yyscan_t yyscanner)
 {
   return 1;
 }
@@ -84,15 +86,3 @@ new_escaped_string(pic_state *pic, const char *str)
   pic_free(pic, new_str);
   return v;
 }
-
-void
-init_scanner(const char *str)
-{
-  yy_scan_string(str);
-}
-
-void
-final_scanner()
-{
-  yylex_destroy();
-}