Fixed #8873 (Add syntaxError when there is no RHS for +-)

lib/tokenize.cpp

@@ -8533,6 +8533,8 @@ void Tokenizer::findGarbageCode() const
             syntaxError(tok);
         if (Token::Match(tok, "%cop%|= ]") && !(isCPP() && Token::Match(tok->previous(), "[|, &|= ]")))
             syntaxError(tok);
+        if (Token::Match(tok, "[+-] [;,)]}]"))
+            syntaxError(tok);
     }
 
     // ternary operator without :

test/testgarbage.cpp

@@ -231,6 +231,7 @@ private:
         TEST_CASE(garbageCode198); // #8383
         TEST_CASE(garbageCode199); // #8752
         TEST_CASE(garbageCode200); // #8757
+        TEST_CASE(garbageCode201); // #8873
 
         TEST_CASE(garbageCodeFuzzerClientMode1); // test cases created with the fuzzer client, mode 1
 
@@ -1426,7 +1427,7 @@ private:
     }
 
     void garbageCode181() {
-        checkCode("int test() { int +; }");
+        ASSERT_THROW(checkCode("int test() { int +; }"), InternalError);
     }
 
     // #4195 - segfault for "enum { int f ( ) { return = } r = f ( ) ; }"
@@ -1551,6 +1552,11 @@ private:
         ASSERT_THROW(checkCode("(){e break,{(case)!{e:[]}}}"), InternalError);
     }
 
+    // #8873
+    void garbageCode201() {
+        ASSERT_THROW(checkCode("void f() { std::string s=\"abc\"; return s + }"), InternalError);
+    }
+
     void syntaxErrorFirstToken() {
         ASSERT_THROW(checkCode("&operator(){[]};"), InternalError); // #7818
         ASSERT_THROW(checkCode("*(*const<> (size_t); foo) { } *(*const (size_t)() ; foo) { }"), InternalError); // #6858