CXX: Avoid accessing token after it has been destroyed (#2586)

Fixes #2554
Replaces #2559

Author: pragmaware

Units/parser-c.r/bug2554.c.d/args.ctags

@@ -0,0 +1 @@
+--sort=no

Units/parser-c.r/bug2554.c.d/expected.tags

@@ -0,0 +1,7 @@
+__anonbbb2b4710108	input.c	/^{$/;"	s	file:
+n	input.c	/^  int*n;$/;"	m	struct:__anonbbb2b4710108	typeref:typename:int *	file:
+S	input.c	/^} S;$/;"	t	typeref:struct:__anonbbb2b4710108	file:
+foo	input.c	/^struct foo {$/;"	s	file:
+bar	input.c	/^	int bar;$/;"	m	struct:foo	typeref:typename:int	file:
+v	input.c	/^} v = {$/;"	v	typeref:struct:foo
+w	input.c	/^struct foo w = {$/;"	v	typeref:struct:foo

Units/parser-c.r/bug2554.c.d/input.c

@@ -0,0 +1,22 @@
+/* valgrind reported an error when ctags built with
+ * --enable-debugging configure option.
+ *
+ * To reproduce:
+ *
+ *  $ make units LANGUAGES=C VG=1
+ *
+ */
+typedef struct
+{
+  int*n;
+} S;
+
+struct foo {
+	int bar;
+} v = {
+	.bar = 1,
+};
+
+struct foo w = {
+	.bar = 2,
+};

parsers/cxx/cxx_parser.c

@@ -494,8 +494,11 @@ static bool cxxParserParseEnumStructClassOrUnionFullDeclarationTrailer(
 	MIOPos oFilePosition = getInputFilePosition();
 	int iFileLine = getInputLineNumber();
 
-	if(!cxxParserParseUpToOneOf(CXXTokenTypeEOF | CXXTokenTypeSemicolon | CXXTokenTypeOpeningBracket
-								| CXXTokenTypeAssignment, false))
+	if(!cxxParserParseUpToOneOf(
+			CXXTokenTypeEOF | CXXTokenTypeSemicolon |
+				CXXTokenTypeOpeningBracket | CXXTokenTypeAssignment,
+			false
+		))
 	{
 		CXX_DEBUG_LEAVE_TEXT("Failed to parse up to EOF/semicolon");
 		return false;
@@ -556,30 +559,23 @@ static bool cxxParserParseEnumStructClassOrUnionFullDeclarationTrailer(
 		return true;
 	}
 
+	if(cxxTokenTypeIs(g_cxx.pToken,CXXTokenTypeAssignment))
+	{
+		if(!cxxParserParseUpToOneOf(
+				CXXTokenTypeEOF | CXXTokenTypeSemicolon,
+				false
+			))
+		{
+			CXX_DEBUG_LEAVE_TEXT("Failed to parse up to EOF/semicolon");
+			return false;
+		}
+	}
+
 	if(uKeywordState & CXXParserKeywordStateSeenTypedef)
 		cxxParserExtractTypedef(g_cxx.pTokenChain,true);
 	else
 		cxxParserExtractVariableDeclarations(g_cxx.pTokenChain,0);
 
-	/*
-	  Skip initializer in
-
-	  struct foo { ... } x = { ... };
-
-	  if we are at --------^.
-	  we go to ---------------------^.
-
-	  The above example is known case.
-	  To be tolerant and handle unrecognized case, we
-	  put the code for skipping here. */
-	if(cxxTokenTypeIs(g_cxx.pToken,CXXTokenTypeAssignment) &&
-	   (!cxxParserParseUpToOneOf(CXXTokenTypeEOF | CXXTokenTypeSemicolon, true)))
-	{
-		CXX_DEBUG_LEAVE_TEXT("Failed to parse up to EOF/semicolon");
-		return false;
-	}
-
-
 	CXX_DEBUG_LEAVE();
 	return true;
 }