fix #9685 (Handle 'extern "C++"') (#2933)

Author: IOBYTE

lib/tokenize.cpp

@@ -9851,7 +9851,7 @@ void Tokenizer::findGarbageCode() const
         for (const Token *tok = tokens(); tok; tok = tok->next()) {
             if (!Token::simpleMatch(tok, "template <"))
                 continue;
-            if (tok->previous() && !Token::Match(tok->previous(), "[:;{})>]")) {
+            if (tok->previous() && !Token::Match(tok->previous(), ":|;|{|}|)|>|\"C++\"")) {
                 if (tok->previous()->isUpperCaseName())
                     unknownMacroError(tok->previous());
                 else

test/testsimplifytemplate.cpp

@@ -205,6 +205,7 @@ class TestSimplifyTemplate : public TestFixture {
         TEST_CASE(template160);
         TEST_CASE(template161);
         TEST_CASE(template162);
+        TEST_CASE(template163); // #9685 syntax error
         TEST_CASE(template_specialization_1);  // #7868 - template specialization template <typename T> struct S<C<T>> {..};
         TEST_CASE(template_specialization_2);  // #7868 - template specialization template <typename T> struct S<C<T>> {..};
         TEST_CASE(template_enum);  // #6299 Syntax error in complex enum declaration (including template)
@@ -4108,6 +4109,11 @@ class TestSimplifyTemplate : public TestFixture {
         ASSERT_EQUALS(exp, tok(code));
     }
 
+    void template163() { // #9685 syntax error
+        const char code[] = "extern \"C++\" template < typename T > T * test ( ) { return nullptr ; }";
+        ASSERT_EQUALS(code, tok(code));
+    }
+
     void template_specialization_1() {  // #7868 - template specialization template <typename T> struct S<C<T>> {..};
         const char code[] = "template <typename T> struct C {};\n"
                             "template <typename T> struct S {a};\n"