json: improve parser reentrability

* include/grecs/json.h (jsonlex_cleanup): New proto.
* src/json-lex.l (jsonlex_setup): Initialize parser state.
Initialize json_current_locus_point.file to a non-NULL value.
(jsonlex_cleanup): New function.
* src/json-gram.y (json_parse_string): Call jsonlex_cleanup before returning.
* src/diag.c (default_print_diag): Print the passed errcode argument,
instead of errno.

3 files changed, 25 insertions, 13 deletions

diff --git a/src/diag.c b/src/diag.c
index bdbb407..db96e75 100644
--- a/src/diag.c
+++ b/src/diag.c
@@ -28,25 +28,25 @@ default_print_diag(grecs_locus_t const *locus, int err, int errcode,
 		   const char *msg)
 {
 	fflush(stdout);
 	if (locus) {
 		YY_LOCATION_PRINT(stderr, *locus);
 		fputc(':', stderr);
 		fputc(' ', stderr);
 	}
 	if (!err)
 		fprintf(stderr, "warning: ");
 	fprintf(stderr, "%s", msg);
 	if (errcode)
-		fprintf(stderr, ": %s", strerror(errno));
+		fprintf(stderr, ": %s", strerror(errcode));
 	fputc('\n', stderr);
 }
 
 void (*grecs_print_diag_fun)(grecs_locus_t const *, int, int,
 			     const char *msg) =
 	default_print_diag;
 
 void
 grecs_warning(grecs_locus_t const *locus, int errcode, const char *fmt, ...)
 {
 	va_list ap;
 	char *buf = NULL;
diff --git a/src/json-gram.y b/src/json-gram.y
index fe8996b..d5b0248 100644
--- a/src/json-gram.y
+++ b/src/json-gram.y
@@ -271,24 +271,25 @@ json_assoc_create()
 				   NULL,
 				   json_st_free);
 }
 
 struct json_value *
 json_parse_string(char const *input, size_t len)
 {
 	jsonlex_setup(input, len);
 	if (yyparse()) {
 		/* FIXME: error recovery */
 		return NULL;
 	}
+	jsonlex_cleanup();
 	return json_return_obj;
 }
 
 struct json_value *
 json_value_lookup(struct json_value *obj, const char *ident)
 {
 	char *qbuf = NULL;
 	size_t qlen = 0;
 	
 	while (obj && *ident) {
 		char const *p;
 		char *q;
diff --git a/src/json-lex.l b/src/json-lex.l
index 169cf32..4bbdedf 100644
--- a/src/json-lex.l
+++ b/src/json-lex.l
@@ -46,36 +46,24 @@ struct grecs_locus json_err_locus;
 	} while(0)
 
 #define YY_USER_ACTION do {						\
 		if (YYSTATE == 0) {					\
 			yylloc.beg = json_current_locus_point;		\
 			yylloc.beg.col++;				\
 		}							\
   		json_current_locus_point.col += yyleng;			\
  		yylloc.end = json_current_locus_point;			\
    	} while (0);
 
 void
-jsonlex_setup(char const *s, size_t l)
-{
-	input_ptr = s;
-	input_size = l;
-	json_current_locus_point.file = NULL;
-	json_current_locus_point.line = 1;
-	json_current_locus_point.col = 0;
-	json_err_diag = NULL;
-	yy_flex_debug = 0;
-}
-
-void
 jsonlex_diag(const char *s)
 {
 	if (!json_err_diag) {
 		json_err_diag = s;
 		json_err_locus = yylloc;
 	}
 }
 		
 static int
 utf8_wctomb(char *u)
 {
 	unsigned int wc = strtoul(u, NULL, 16);
@@ -218,12 +206,35 @@ X [0-9a-fA-F]
                              return T_ERR;
                      }
                      json_line_grow(&c, 1); }
 
 null      { return T_NULL; }
 true      { yylval.b = 1; return T_BOOL; }
 false     { yylval.b = 0; return T_BOOL; }
 "{"|"}"|"["|"]"|":"|","  return yytext[0];
 [ \t]*    ;
 \n        grecs_locus_point_advance_line(json_current_locus_point);
 .         { jsonlex_diag("bogus character");
             return T_ERR; }
+%%
+void
+jsonlex_setup(char const *s, size_t l)
+{
+	input_ptr = s;
+	input_size = l;
+	json_current_locus_point.file = "input";
+	json_current_locus_point.line = 1;
+	json_current_locus_point.col = 0;
+	json_err_diag = NULL;
+        yy_flex_debug = 0;
+        BEGIN(INITIAL);
+        yyrestart(NULL);
+}
+
+void
+jsonlex_cleanup(void)
+{
+        if (json_line_acc) {
+	        grecs_txtacc_free(json_line_acc);
+                json_line_acc = NULL;
+	}
+}