removed usage of emptyString from error messages

these can be considered cold paths in the optimal case i.e. no errors

Author: firewave

Diff for: lib/checkclass.cpp

@@ -2038,7 +2038,7 @@ void CheckClass::virtualDestructor()
     }
 
     for (const Function *func : inconclusiveErrors)
-        virtualDestructorError(func->tokenDef, func->name(), emptyString, true);
+        virtualDestructorError(func->tokenDef, func->name(), "", true);
 }
 
 void CheckClass::virtualDestructorError(const Token *tok, const std::string &Base, const std::string &Derived, bool inconclusive)

Diff for: lib/checkinternal.cpp

@@ -126,7 +126,7 @@ void CheckInternal::checkRedundantTokCheck()
 void CheckInternal::checkRedundantTokCheckError(const Token* tok)
 {
     reportError(tok, Severity::style, "redundantTokCheck",
-                "Unnecessary check of \"" + (tok? tok->expressionString(): emptyString) + "\", match-function already checks if it is null.");
+                "Unnecessary check of \"" + (tok? tok->expressionString(): "") + "\", match-function already checks if it is null.");
 }
 
 void CheckInternal::checkTokenSimpleMatchPatterns()

Diff for: lib/checkother.cpp

@@ -3512,7 +3512,7 @@ void CheckOther::unusedLabelError(const Token* tok, bool inSwitch, bool hasIfdef
     if (hasIfdef)
         id += "Configuration";
 
-    std::string msg = "$symbol:" + (tok ? tok->str() : emptyString) + "\nLabel '$symbol' is not used.";
+    std::string msg = "$symbol:" + (tok ? tok->str() : "") + "\nLabel '$symbol' is not used.";
     if (hasIfdef)
         msg += " There is #if in function body so the label might be used in code that is removed by the preprocessor.";
     if (inSwitch)

Diff for: lib/checkstl.cpp

@@ -2514,7 +2514,7 @@ void CheckStl::checkDereferenceInvalidIterator2()
                     outOfBoundsError(emptyAdvance,
                                      lValue.tokvalue->expressionString(),
                                      cValue,
-                                     advanceIndex ? advanceIndex->expressionString() : emptyString,
+                                     advanceIndex ? advanceIndex->expressionString() : "",
                                      nullptr);
                 else
                     outOfBoundsError(tok, lValue.tokvalue->expressionString(), cValue, tok->expressionString(), &value);
@@ -3148,7 +3148,7 @@ void CheckStl::knownEmptyContainer()
                 const Token* contTok = splitTok->astOperand2();
                 if (!isKnownEmptyContainer(contTok))
                     continue;
-                knownEmptyContainerError(contTok, emptyString);
+                knownEmptyContainerError(contTok, "");
             } else {
                 const std::vector<const Token *> args = getArguments(tok);
                 if (args.empty())

Diff for: lib/checkuninitvar.cpp

@@ -650,7 +650,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
                     // Assert that the tokens are '} while ('
                     if (!Token::simpleMatch(tok, "} while (")) {
                         if (printDebug)
-                            reportError(tok,Severity::debug,emptyString,"assertion failed '} while ('");
+                            reportError(tok,Severity::debug,"","assertion failed '} while ('");
                         break;
                     }
 

Diff for: lib/errorlogger.h

@@ -196,7 +196,7 @@ class CPPCHECKLIB ErrorMessage {
         return mSymbolNames;
     }
 
-    static ErrorMessage fromInternalError(const InternalError &internalError, const TokenList *tokenList, const std::string &filename, const std::string& msg = emptyString);
+    static ErrorMessage fromInternalError(const InternalError &internalError, const TokenList *tokenList, const std::string &filename, const std::string& msg = "");
 
 private:
     static std::string fixInvalidChars(const std::string& raw);

Diff for: lib/preprocessor.cpp

@@ -878,7 +878,7 @@ void Preprocessor::reportOutput(const simplecpp::OutputList &outputList, bool sh
         case simplecpp::Output::EXPLICIT_INCLUDE_NOT_FOUND:
         case simplecpp::Output::FILE_NOT_FOUND:
         case simplecpp::Output::DUI_ERROR:
-            error(emptyString, 0, out.msg);
+            error("", 0, out.msg);
             break;
         }
     }

Diff for: lib/tokenize.h

@@ -374,7 +374,7 @@ class CPPCHECKLIB Tokenizer {
 public:
 
     /** Syntax error */
-    NORETURN void syntaxError(const Token *tok, const std::string &code = emptyString) const;
+    NORETURN void syntaxError(const Token *tok, const std::string &code = "") const;
 
     /** Syntax error. Unmatched character. */
     NORETURN void unmatchedToken(const Token *tok) const;