Merge pull request #2740 from masatake/r-r6class-avoid-entering-infinite-loop

R6class: avoid entering infinite loop

Author: masatake

Units/parser-r6class.r/infinite-loop.d/input-0.r

@@ -0,0 +1 @@
+e <- R6Class(public = list({}}

Units/parser-r6class.r/infinite-loop.d/input.r

@@ -0,0 +1,2 @@
+# NOTHING HERE
+

Units/simple-r6class.d/args.ctags Units/parser-r6class.r/simple-r6class.d/args.ctags

@@ -108,7 +108,11 @@ void tokenReadFull (tokenInfo *token, void *data)
 		tokenDelete (backlog);
 	}
 	else
+	{
 		token->klass->read (token, data);
+		if (!tokenIsEOF (token))
+			token->klass->read_counter++;
+	}
 }
 
 void tokenRead (tokenInfo *token)

Units/simple-r6class.d/expected.tags Units/parser-r6class.r/simple-r6class.d/expected.tags

@@ -53,6 +53,14 @@ struct tokenInfoClass {
 	void (*copy)   (tokenInfo *dest, tokenInfo *src, void *data);
 	objPool *pool;
 	ptrArray *backlog;
+
+	/* read_counter is incremented every time when reading a
+	 * new token from the input stream unless the new token is EOF.
+	 *
+	 * When filling a tokenInfo from an entry in the backlog, we don't
+	 * regard it as "reading a new token".
+	 */
+	int read_counter;
 };
 
 void *newToken       (struct tokenInfoClass *klass);

Units/simple-r6class.d/input.r Units/parser-r6class.r/simple-r6class.d/input.r

@@ -130,10 +130,11 @@ static void parseListMain (rSubparser *s,
 
 	rTokenReadNoNewline (token);
 
-	while (! (tokenIsEOF (token) || tokenIsTypeVal (token, ')')))
+	while (! tokenIsTypeVal (token, ')'))
 	{
-		rParseStatement (token, classIndex, false);
-		if (tokenIsTypeVal (token, '\n'))
+		if (!rParseStatement (token, classIndex, false))
+			break;
+		else if (tokenIsTypeVal (token, '\n'))
 			rTokenReadNoNewline (token);
 	}
 	((struct r6Subparser *)s)->access = last_access;

main/tokeninfo.c

@@ -93,11 +93,11 @@ static void parseRepresentation (rSubparser *s, tokenInfo *const token, int pare
 	if (tokenIsTypeVal (token, '('))
 	{
 		rTokenReadNoNewline (token);
-		while (!(tokenIsEOF (token)
-				 || tokenIsTypeVal (token, ')') || tokenIsTypeVal (token, ',')))
+		while (!(tokenIsTypeVal (token, ')') || tokenIsTypeVal (token, ',')))
 		{
-			rParseStatement (token, parent, false);
-			if (tokenIsTypeVal (token, '\n'))
+			if (!rParseStatement (token, parent, false))
+				break;
+			else if (tokenIsTypeVal (token, '\n'))
 				rTokenReadNoNewline (token);
 		}
 	}
@@ -204,10 +204,11 @@ static bool parseMethodArgs (rSubparser *s, tokenInfo *const token, int parent,
 			{
 				rTokenReadNoNewline (token);
 				/* anonymous function for implementing this method may be here.*/
-				while (!(tokenIsEOF (token) || tokenIsTypeVal (token, ')')))
+				while (!tokenIsTypeVal (token, ')'))
 				{
-					rParseStatement (token, parent, true);
-					if (tokenIsTypeVal (token, '\n'))
+					if (!rParseStatement (token, parent, true))
+						break;
+					else if (tokenIsTypeVal (token, '\n'))
 						rTokenReadNoNewline (token);
 				}
 			}
@@ -228,11 +229,11 @@ static bool parseMethodArgs (rSubparser *s, tokenInfo *const token, int parent,
 static bool parseGenericArgs (rSubparser *s, tokenInfo *const token, int parent,
 							  tokenInfo *const open_paren)
 {
-	while (!(tokenIsEOF (token)
-			 || tokenIsTypeVal (token, ')')))
+	while (!tokenIsTypeVal (token, ')'))
 	{
-		rParseStatement (token, parent, true);
-		if (tokenIsTypeVal (token, '\n'))
+		if (!rParseStatement (token, parent, true))
+			break;
+		else if (tokenIsTypeVal (token, '\n'))
 			rTokenReadNoNewline (token);
 	}
 	return false;

main/tokeninfo.h

@@ -194,7 +194,7 @@ static struct tokenInfoClass rTokenInfoClass = {
 /*
  * FUNCTION PROTOTYPES
  */
-static void parseStatement (tokenInfo *const token, int parent, bool in_arglist, bool in_continuous_pair);
+static bool parseStatement (tokenInfo *const token, int parent, bool in_arglist, bool in_continuous_pair);
 static void parsePair (tokenInfo *const token, int parent, tokenInfo *const funcall);
 
 static  int notifyReadRightSideSymbol (tokenInfo *const symbol,
@@ -930,10 +930,11 @@ static void parsePair (tokenInfo *const token, int parent, tokenInfo *const func
 	R_TRACE_LEAVE();
 }
 
-static void parseStatement (tokenInfo *const token, int parent,
+static bool parseStatement (tokenInfo *const token, int parent,
 							bool in_arglist, bool in_continuous_pair)
 {
 	R_TRACE_ENTER();
+	int last_count = rTokenInfoClass.read_counter;
 
 	do
 	{
@@ -1071,13 +1072,16 @@ static void parseStatement (tokenInfo *const token, int parent,
 	while (!tokenIsEOF (token));
 
 	R_TRACE_LEAVE();
+
+	return (last_count != rTokenInfoClass.read_counter);
 }
 
-extern void rParseStatement (tokenInfo *const token, int parentIndex, bool in_arglist)
+extern bool rParseStatement (tokenInfo *const token, int parentIndex, bool in_arglist)
 {
 	pushLanguage (Lang_R);
-	parseStatement (token, parentIndex, in_arglist, true);
+	bool r = parseStatement (token, parentIndex, in_arglist, true);
 	popLanguage ();
+	return r;
 }
 
 static  int notifyReadRightSideSymbol (tokenInfo *const symbol,

parsers/r-r6class.c

@@ -97,7 +97,11 @@ extern void rTeardownCollectingSignature (tokenInfo *const token);
  */
 
 extern void rTokenReadNoNewline (tokenInfo *const token);
-extern void rParseStatement (tokenInfo *const token, int parentIndex, bool inArgList);
+
+/* This function returns true if a new token is read.
+ * EOF is exception. If EOF is read, this function returns FALSE. */
+extern bool rParseStatement (tokenInfo *const token, int parentIndex, bool inArgList);
+
 extern vString *rExtractNameFromString (vString* str);
 
 #endif	/* CTAGS_PARSER_TEX_H */