Partial fix for #11522 FP AssignmentIntegerToAddress with function pointer (#8009)

Author: chrchr-github

lib/check64bit.cpp

@@ -48,6 +48,13 @@ static bool is32BitIntegerReturn(const Function* func, const Settings* settings)
     return vt && vt->pointer == 0 && vt->isIntegral() && vt->typeSize(settings->platform) == 4;
 }
 
+static bool isFunctionPointer(const Token* tok)
+{
+    if (!tok || !tok->variable())
+        return false;
+    return Tokenizer::isFunctionPointer(tok->variable()->nameToken());
+}
+
 void Check64BitPortability::pointerassignment()
 {
     if (!mSettings->severity.isEnabled(Severity::portability))
@@ -120,7 +127,8 @@ void Check64BitPortability::pointerassignment()
                 !tok->astOperand2()->isNumber() &&
                 rhstype->pointer == 0U &&
                 rhstype->originalTypeName.empty() &&
-                rhstype->type == ValueType::Type::INT)
+                rhstype->type == ValueType::Type::INT &&
+                !isFunctionPointer(tok->astOperand1()))
                 assignmentIntegerToAddressError(tok);
 
             // Assign pointer to integer..

lib/tokenize.cpp

@@ -674,7 +674,7 @@ namespace {
                 return;
 
             mUsed = true;
-            const bool isFunctionPointer = Token::Match(mNameToken, "%name% )");
+            const bool isFunctionPointer = Tokenizer::isFunctionPointer(mNameToken);
 
             // Special handling for T(...) when T is a pointer
             if (Token::Match(tok, "%name% [({]") && !isFunctionPointer && !Token::simpleMatch(tok->linkAt(1), ") (")) {
@@ -1019,6 +1019,10 @@ namespace {
     };
 }
 
+bool Tokenizer::isFunctionPointer(const Token* tok) {
+    return Token::Match(tok, "%name% ) (");
+}
+
 void Tokenizer::simplifyTypedef()
 {
     // Simplify global typedefs that are not redefined with the fast 1-pass simplification.
@@ -1088,7 +1092,7 @@ void Tokenizer::simplifyTypedef()
                 typedefInfo.lineNumber = typedefToken->linenr();
                 typedefInfo.column = typedefToken->column();
                 typedefInfo.used = t.second.isUsed();
-                typedefInfo.isFunctionPointer = Token::Match(t.second.nameToken(), "%name% ) (");
+                typedefInfo.isFunctionPointer = isFunctionPointer(t.second.nameToken());
                 if (typedefInfo.isFunctionPointer) {
                     const Token* tok = typedefToken;
                     while (tok != t.second.endToken()) {
@@ -1622,7 +1626,7 @@ void Tokenizer::simplifyTypedefCpp()
         typedefInfo.lineNumber = typeName->linenr();
         typedefInfo.column = typeName->column();
         typedefInfo.used = false;
-        typedefInfo.isFunctionPointer = Token::Match(typeName, "%name% ) (");
+        typedefInfo.isFunctionPointer = isFunctionPointer(typeName);
         if (typedefInfo.isFunctionPointer) {
             const Token* t = typeDef;
             while (t != tok) {
@@ -7155,7 +7159,7 @@ void Tokenizer::simplifyFunctionPointers()
         while (Token::Match(tok2, "%type%|:: %type%|::"))
             tok2 = tok2->next();
 
-        if (!Token::Match(tok2, "%name% ) (") &&
+        if (!isFunctionPointer(tok2) &&
             !Token::Match(tok2, "%name% [ ] ) (") &&
             !(Token::Match(tok2, "%name% (") && Token::simpleMatch(tok2->linkAt(1), ") ) (")))
             continue;
@@ -7448,7 +7452,7 @@ void Tokenizer::simplifyVarDecl(Token * tokBegin, const Token * const tokEnd, co
             }
             // Function pointer
             if (Token::simpleMatch(varName, "( *") &&
-                Token::Match(varName->link()->previous(), "%name% ) (") &&
+                isFunctionPointer(varName->link()->previous()) &&
                 Token::simpleMatch(varName->link()->linkAt(1), ") =")) {
                 Token *endDecl = varName->link()->linkAt(1);
                 varName = varName->link()->previous();
@@ -9376,7 +9380,7 @@ Token* Tokenizer::getAttributeFuncTok(Token* tok, bool gccattr) const {
         if (Token::simpleMatch(prev, ")")) {
             if (Token::Match(prev->link()->previous(), "%name% ("))
                 return prev->link()->previous();
-            if (Token::Match(prev->link()->tokAt(-2), "%name% ) ("))
+            if (isFunctionPointer(prev->link()->tokAt(-2)))
                 return prev->link()->tokAt(-2);
         }
         if (Token::simpleMatch(prev, ")") && Token::Match(prev->link()->tokAt(-2), "operator %op% (") && isCPP())

lib/tokenize.h

@@ -601,7 +601,7 @@ class CPPCHECKLIB Tokenizer {
     /**
      * Helper function to check whether number is one (1 or 0.1E+1 or 1E+0) or not?
      * @param s the string to check
-     * @return true in case is is one and false otherwise.
+     * @return true in case it is one and false otherwise.
      */
     static bool isOneNumber(const std::string &s);
 
@@ -613,6 +613,13 @@ class CPPCHECKLIB Tokenizer {
      */
     static const Token * startOfExecutableScope(const Token * tok);
 
+    /**
+     * Helper function to check whether tok is the declaration of a function pointer
+     * @param tok the Token to check
+     * @return true in case tok is a function pointer and false otherwise.
+     */
+    static bool isFunctionPointer(const Token* tok);
+
     const Settings &getSettings() const {
         return mSettings;
     }

test/test64bit.cpp

@@ -67,6 +67,12 @@ class Test64BitPortability : public TestFixture {
               "    t.a[i][j] = new std::vector<int>;\n"
               "}\n");
         ASSERT_EQUALS("", errout_str());
+
+        check("int f();\n" // #11522
+              "void g() {\n"
+              "    int (*fp)() = *(int(*)())f;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
     }
 
     void novardecl() {