More robust template detection in clarifyCondition check based on Token::link. (#3818)

Create links between < and > only on non-C code.
AStyle fix

lib/checkother.cpp

@@ -156,7 +156,7 @@ void CheckOther::clarifyCondition()
                     tok2 = tok2->link();
                 else if (tok2->type() == Token::eComparisonOp) {
                     // This might be a template
-                    if (!isC && Token::Match(tok2->previous(), "%var% <"))
+                    if (!isC && tok2->link())
                         break;
 
                     clarifyConditionError(tok, tok->strAt(2) == "=", false);
@@ -170,6 +170,9 @@ void CheckOther::clarifyCondition()
     // using boolean result in bitwise operation ! x [&|^]
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
         if (Token::Match(tok, "!|<|<=|==|!=|>|>=")) {
+            if (tok->link()) // don't write false positives when templates are used
+                continue;
+
             const Token *tok2 = tok->next();
 
             // Todo: There are false positives if '(' if encountered. It
@@ -186,8 +189,7 @@ void CheckOther::clarifyCondition()
 
             if (Token::Match(tok2, "[&|^]")) {
                 // don't write false positives when templates are used
-                if (Token::Match(tok, "<|>") && (Token::Match(tok2, "& ,|>") ||
+                if (Token::Match(tok2, "&|* ,|>") || Token::simpleMatch(tok2->previous(), "const &"))
-                                                 Token::simpleMatch(tok2->previous(), "const &")))
                     continue;
 
                 // #3609 - CWinTraits<WS_CHILD|WS_VISIBLE>::..

lib/tokenize.cpp

@@ -2935,6 +2935,9 @@ bool Tokenizer::createLinks()
 
 void Tokenizer::createLinks2()
 {
+    if (isC())
+        return;
+
     std::stack<const Token*> type;
     std::stack<Token*> links;
     for (Token *token = list.front(); token; token = token->next()) {
@@ -7836,7 +7839,7 @@ void Tokenizer::simplifyComma()
 
 void Tokenizer::removeExceptionSpecifications()
 {
-    for(Token* tok = list.front(); tok; tok = tok->next()) {
+    for (Token* tok = list.front(); tok; tok = tok->next()) {
         if (Token::Match(tok, ") const| throw (")) {
             if (tok->next()->str() == "const") {
                 Token::eraseTokens(tok->next(), tok->linkAt(3));

test/testother.cpp

@@ -124,6 +124,7 @@ private:
         TEST_CASE(clarifyCondition3);     // if (! a & b)
         TEST_CASE(clarifyCondition4);     // ticket #3110
         TEST_CASE(clarifyCondition5);     // #3609 CWinTraits<WS_CHILD|WS_VISIBLE>..
+        TEST_CASE(clarifyCondition6);     // #3818
         TEST_CASE(bitwiseOnBoolean);      // if (bool & bool)
 
         TEST_CASE(comparisonOfBoolExpressionWithInt1);
@@ -3657,6 +3658,15 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void clarifyCondition6() {
+        check("template<class Y>\n"
+              "SharedPtr& operator=( SharedPtr<Y> const & r ) {\n"
+              "    px = r.px;\n"
+              "    return *this;\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void bitwiseOnBoolean() { // 3062
         check("void f(_Bool a, _Bool b) {\n"
               "    if(a & b) {}\n"