Fixed #10196 ("Unhandled char constant 'x'" with non-standard escape character)

danmar · danmar · commit abb42003164e · 2021-05-08T12:54:18.000+02:00
diff --git a/lib/cppcheck.cpp b/lib/cppcheck.cpp
@@ -835,7 +835,8 @@ unsigned int CppCheck::checkFile(const std::string& filename, const std::string
                     ErrorMessage::FileLocation loc(tokenizer.list.getSourceFilePath(), 0, 0);
                     ErrorMessage::FileLocation loc2(filename, 0, 0);
                     locationList.push_back(loc2);
-                    locationList.push_back(loc);
+                    if (filename != tokenizer.list.getSourceFilePath())
+                        locationList.push_back(loc);
                 }
                 ErrorMessage errmsg(locationList,
                                     tokenizer.list.getSourceFilePath(),
diff --git a/lib/mathlib.cpp b/lib/mathlib.cpp
@@ -505,13 +505,8 @@ MathLib::bigint MathLib::toLongNumber(const std::string & str)
             return static_cast<bigint>(doubleval);
     }
 
-    if (isCharLiteral(str)) {
-        try {
-            return simplecpp::characterLiteralToLL(str);
-        } catch (const std::exception& e) {
-            throw InternalError(nullptr, "Internal Error. MathLib::toLongNumber: characterLiteralToLL(" + str + ") => " + e.what());
-        }
-    }
+    if (isCharLiteral(str))
+        return simplecpp::characterLiteralToLL(str);
 
     try {
         const biguint ret = std::stoull(str, nullptr, 10);
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
@@ -2766,6 +2766,19 @@ bool Tokenizer::simplifyTokens1(const std::string &configuration)
         ValueFlow::setValues(&list, mSymbolDatabase, mErrorLogger, mSettings);
     }
 
+    // Warn about unhandled character literals
+    if (mSettings->severity.isEnabled(Severity::information)) {
+        for (const Token *tok = tokens(); tok; tok = tok->next()) {
+            if (tok->tokType() == Token::eChar && tok->values().empty()) {
+                try {
+                    simplecpp::characterLiteralToLL(tok->str());
+                } catch (const std::exception &e) {
+                    unhandledCharLiteral(tok, e.what());
+                }
+            }
+        }
+    }
+
     mSymbolDatabase->setArrayDimensionsUsingValueFlow();
 
     printDebugOutput(1);
@@ -9528,6 +9541,21 @@ void Tokenizer::cppcheckError(const Token *tok) const
     printDebugOutput(0);
     throw InternalError(tok, "Analysis failed. If the code is valid then please report this failure.", InternalError::INTERNAL);
 }
+
+void Tokenizer::unhandledCharLiteral(const Token *tok, const std::string& msg) const
+{
+    std::string s = tok ? (" " + tok->str()) : "";
+    for (int i = 0; i < s.size(); ++i) {
+        if ((unsigned char)s[i] >= 0x80)
+            s.clear();
+    }
+
+    reportError(tok,
+                Severity::information,
+                "cppcheckUnhandledChar",
+                "Character literal" + s + " is not handled. " + msg);
+}
+
 /**
  * Helper function to check whether number is equal to integer constant X
  * or floating point pattern X.0
diff --git a/lib/tokenize.h b/lib/tokenize.h
@@ -652,6 +652,8 @@ class CPPCHECKLIB Tokenizer {
     /** Warn about unknown macro(s), configuration is recommended */
     NORETURN void unknownMacroError(const Token *tok1) const;
 
+    void unhandledCharLiteral(const Token *tok, const std::string& msg) const;
+
 private:
 
     /** Report that there is an unhandled "class x y {" code */
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
@@ -913,10 +913,14 @@ size_t ValueFlow::getSizeOf(const ValueType &vt, const Settings *settings)
 static Token * valueFlowSetConstantValue(Token *tok, const Settings *settings, bool cpp)
 {
     if ((tok->isNumber() && MathLib::isInt(tok->str())) || (tok->tokType() == Token::eChar)) {
-        ValueFlow::Value value(MathLib::toLongNumber(tok->str()));
-        if (!tok->isTemplateArg())
-            value.setKnown();
-        setTokenValue(tok, value, settings);
+        try {
+            ValueFlow::Value value(MathLib::toLongNumber(tok->str()));
+            if (!tok->isTemplateArg())
+                value.setKnown();
+            setTokenValue(tok, value, settings);
+        } catch (const std::exception &e) {
+            // Bad character literal
+        }
     } else if (tok->isNumber() && MathLib::isFloat(tok->str())) {
         ValueFlow::Value value;
         value.valueType = ValueFlow::Value::ValueType::FLOAT;
