Fix #13873 (Tokenizer: do not simplify 'using' in function declaration/definition for function name)

lib/tokenize.cpp

@@ -2650,6 +2650,22 @@ namespace {
             return false;
         }
 
+        if (Token::Match(tok1, "%name% (") && TokenList::isFunctionHead(tok1->next(), "{;:")) {
+            if (Token::Match(tok1->previous(), "%name%") && !tok1->previous()->isControlFlowKeyword())
+                return false;
+            if (Token::Match(tok1->previous(), ">|>>") && tok1->linkAt(-1))
+                return false;
+            if (Token::Match(tok1->previous(), "*|&|&&")) {
+                const Token* prev = tok1->previous();
+                while (Token::Match(prev, "%name%|*|&|&&|::") && !prev->isControlFlowKeyword())
+                    prev = prev->previous();
+                if (Token::Match(prev, ">|>>") && tok1->linkAt(-1))
+                    return false;
+                if (Token::Match(prev, "[;{}] %name%"))
+                    return false;
+            }
+        }
+
         // get qualification
         std::string qualification;
         const Token* tok2 = tok1;
@@ -3027,6 +3043,8 @@ bool Tokenizer::simplifyUsing()
             }
         }
 
+        bool isTypedefInfoAdded = false; // TODO should we add a separate mUsingInfo?
+
         std::string scope1 = currentScope1->fullName;
         bool skip = false; // don't erase type aliases we can't parse
         Token *enumOpenBrace = nullptr;
@@ -3097,6 +3115,18 @@ bool Tokenizer::simplifyUsing()
             } else if (!usingMatch(nameToken, scope, tok1, scope1, currentScope1, nullptr))
                 continue;
 
+            if (!isTypedefInfoAdded && Token::Match(tok1, "%name% (")) {
+                isTypedefInfoAdded = true;
+                TypedefInfo usingInfo;
+                usingInfo.name = name;
+                usingInfo.filename = list.file(nameToken);
+                usingInfo.lineNumber = nameToken->linenr();
+                usingInfo.column = nameToken->column();
+                usingInfo.used = true;
+                usingInfo.isFunctionPointer = false;
+                mTypedefInfo.push_back(std::move(usingInfo));
+            }
+
             const auto nReplace = tokDistance(start, usingEnd);
             if (nReplace > maxReplacementTokens) {
                 simplifyUsingError(usingStart, usingEnd);

test/testsimplifyusing.cpp

@@ -91,6 +91,7 @@ class TestSimplifyUsing : public TestFixture {
         TEST_CASE(simplifyUsing10173);
         TEST_CASE(simplifyUsing10335);
         TEST_CASE(simplifyUsing10720);
+        TEST_CASE(simplifyUsing13873); // function declaration
 
         TEST_CASE(scopeInfo1);
         TEST_CASE(scopeInfo2);
@@ -1586,6 +1587,20 @@ class TestSimplifyUsing : public TestFixture {
         TODO_ASSERT(startsWith(errout_str(), "[test.cpp:6]: (debug) Failed to parse 'using C = S < S < S < int"));
     }
 
+    void simplifyUsing13873() { // function declaration
+        const char code1[] = "using NS1::f;\n"
+                             "namespace NS1 { void f(); }\n";
+        ASSERT_EQUALS("namespace NS1 { void f ( ) ; }", tok(code1));
+
+        const char code2[] = "using NS1::f;\n"
+                             "void bar() { f(); }\n";
+        ASSERT_EQUALS("void bar ( ) { NS1 :: f ( ) ; }", tok(code2));
+
+        const char code3[] = "using NS1::f;\n"
+                             "namespace NS1 { void* f(); }\n";
+        ASSERT_EQUALS("namespace NS1 { void * f ( ) ; }", tok(code3));
+    }
+
     void scopeInfo1() {
         const char code[] = "struct A {\n"
                             "    enum class Mode { UNKNOWN, ENABLED, NONE, };\n"