Meta: replace empty-string assignments with `clear()`.

Source/CPack/IFW/cmCPackIFWGenerator.cxx

@@ -258,7 +258,7 @@ int cmCPackIFWGenerator::InitializeInternal()
 
   const char* BinCreatorStr = this->GetOption(BinCreatorOpt);
   if (!BinCreatorStr || cmSystemTools::IsNOTFOUND(BinCreatorStr)) {
-    this->BinCreator = "";
+    this->BinCreator.clear();
   } else {
     this->BinCreator = BinCreatorStr;
   }
@@ -274,7 +274,7 @@ int cmCPackIFWGenerator::InitializeInternal()
 
   const char* RepoGenStr = this->GetOption(RepoGenOpt);
   if (!RepoGenStr || cmSystemTools::IsNOTFOUND(RepoGenStr)) {
-    this->RepoGen = "";
+    this->RepoGen.clear();
   } else {
     this->RepoGen = RepoGenStr;
   }

Source/CPack/IFW/cmCPackIFWPackage.cxx

@@ -111,19 +111,19 @@ void cmCPackIFWPackage::DefaultConfiguration()
 {
   this->DisplayName.clear();
   this->Description.clear();
-  this->Version = "";
-  this->ReleaseDate = "";
-  this->Script = "";
+  this->Version.clear();
+  this->ReleaseDate.clear();
+  this->Script.clear();
   this->Licenses.clear();
   this->UserInterfaces.clear();
   this->Translations.clear();
-  this->SortingPriority = "";
-  this->UpdateText = "";
-  this->Default = "";
-  this->Essential = "";
-  this->Virtual = "";
-  this->ForcedInstallation = "";
-  this->RequiresAdminRights = "";
+  this->SortingPriority.clear();
+  this->UpdateText.clear();
+  this->Default.clear();
+  this->Essential.clear();
+  this->Virtual.clear();
+  this->ForcedInstallation.clear();
+  this->RequiresAdminRights.clear();
 }
 
 // Defaul configuration (all in one package)

Source/CPack/IFW/cmCPackIFWRepository.cxx

@@ -62,49 +62,49 @@ bool cmCPackIFWRepository::ConfigureFromOptions()
   if (const char* url = this->GetOption(prefix + "URL")) {
     this->Url = url;
   } else {
-    this->Url = "";
+    this->Url.clear();
   }
 
   // Old url
   if (const char* oldUrl = this->GetOption(prefix + "OLD_URL")) {
     this->OldUrl = oldUrl;
   } else {
-    this->OldUrl = "";
+    this->OldUrl.clear();
   }
 
   // New url
   if (const char* newUrl = this->GetOption(prefix + "NEW_URL")) {
     this->NewUrl = newUrl;
   } else {
-    this->NewUrl = "";
+    this->NewUrl.clear();
   }
 
   // Enabled
   if (this->IsOn(prefix + "DISABLED")) {
     this->Enabled = "0";
   } else {
-    this->Enabled = "";
+    this->Enabled.clear();
   }
 
   // Username
   if (const char* username = this->GetOption(prefix + "USERNAME")) {
     this->Username = username;
   } else {
-    this->Username = "";
+    this->Username.clear();
   }
 
   // Password
   if (const char* password = this->GetOption(prefix + "PASSWORD")) {
     this->Password = password;
   } else {
-    this->Password = "";
+    this->Password.clear();
   }
 
   // DisplayName
   if (const char* displayName = this->GetOption(prefix + "DISPLAY_NAME")) {
     this->DisplayName = displayName;
   } else {
-    this->DisplayName = "";
+    this->DisplayName.clear();
   }
 
   return this->IsValid();

Source/CPack/cmCPackDebGenerator.cxx

@@ -400,7 +400,7 @@ int cmCPackDebGenerator::createDeb()
     compression_suffix = ".gz";
     tar_compression_type = cmArchiveWrite::CompressGZip;
   } else if (!strcmp(debian_compression_type, "none")) {
-    compression_suffix = "";
+    compression_suffix.clear();
     tar_compression_type = cmArchiveWrite::CompressNone;
   } else {
     cmCPackLogger(cmCPackLog::LOG_ERROR,

Source/CPack/cpack.cxx

@@ -135,7 +135,7 @@ int main(int argc, char const* const* argv)
   cpackDefinitions definitions;
   definitions.Log = &log;
 
-  cpackConfigFile = "";
+  cpackConfigFile.clear();
 
   cmsys::CommandLineArguments arg;
   arg.Initialize(argc, argv);

Source/CTest/cmCTestBZR.cxx

@@ -309,11 +309,11 @@ private:
 
           // Hand this line to the subclass implementation.
           if (!this->ProcessLine()) {
-            this->Line = "";
+            this->Line.clear();
             return false;
           }
 
-          this->Line = "";
+          this->Line.clear();
           last_is_new_line = true;
         }
       } else {

Source/CTest/cmCTestBuildAndTestHandler.cxx

@@ -32,7 +32,7 @@ const char* cmCTestBuildAndTestHandler::GetOutput()
 }
 int cmCTestBuildAndTestHandler::ProcessHandler()
 {
-  this->Output = "";
+  this->Output.clear();
   std::string output;
   cmSystemTools::ResetErrorOccuredFlag();
   int retv = this->RunCMakeAndTest(&this->Output);

Source/CTest/cmCTestBuildHandler.cxx

@@ -171,8 +171,8 @@ cmCTestBuildHandler::cmCTestBuildHandler()
 void cmCTestBuildHandler::Initialize()
 {
   this->Superclass::Initialize();
-  this->StartBuild = "";
-  this->EndBuild = "";
+  this->StartBuild.clear();
+  this->EndBuild.clear();
   this->CustomErrorMatches.clear();
   this->CustomErrorExceptions.clear();
   this->CustomWarningMatches.clear();
@@ -190,8 +190,8 @@ void cmCTestBuildHandler::Initialize()
   this->BuildOutputLogSize = 0;
   this->CurrentProcessingLine.clear();
 
-  this->SimplifySourceDir = "";
-  this->SimplifyBuildDir = "";
+  this->SimplifySourceDir.clear();
+  this->SimplifyBuildDir.clear();
   this->OutputLineCounter = 0;
   this->ErrorsAndWarnings.clear();
   this->LastErrorOrWarning = this->ErrorsAndWarnings.end();
@@ -371,8 +371,8 @@ int cmCTestBuildHandler::ProcessHandler()
                                          this->WarningExceptionRegex);
 
   // Determine source and binary tree substitutions to simplify the output.
-  this->SimplifySourceDir = "";
-  this->SimplifyBuildDir = "";
+  this->SimplifySourceDir.clear();
+  this->SimplifyBuildDir.clear();
   if (this->CTest->GetCTestConfiguration("SourceDirectory").size() > 20) {
     std::string srcdir =
       this->CTest->GetCTestConfiguration("SourceDirectory") + "/";
@@ -888,8 +888,8 @@ int cmCTestBuildHandler::RunMakeCommand(const char* command, int* retVal,
         errorwarning.Text =
           "*** WARNING non-zero return value in ctest from: ";
         errorwarning.Text += argv[0];
-        errorwarning.PreContext = "";
-        errorwarning.PostContext = "";
+        errorwarning.PreContext.clear();
+        errorwarning.PostContext.clear();
         errorwarning.Error = false;
         this->ErrorsAndWarnings.push_back(errorwarning);
         this->TotalWarnings++;
@@ -911,8 +911,8 @@ int cmCTestBuildHandler::RunMakeCommand(const char* command, int* retVal,
     errorwarning.LogLine = 1;
     errorwarning.Text = "*** ERROR executing: ";
     errorwarning.Text += cmsysProcess_GetErrorString(cp);
-    errorwarning.PreContext = "";
-    errorwarning.PostContext = "";
+    errorwarning.PreContext.clear();
+    errorwarning.PostContext.clear();
     errorwarning.Error = true;
     this->ErrorsAndWarnings.push_back(errorwarning);
     this->TotalErrors++;
@@ -996,8 +996,8 @@ void cmCTestBuildHandler::ProcessBuffer(const char* data, size_t length,
         // This is an error or warning, so generate report
         errorwarning.LogLine = static_cast<int>(this->OutputLineCounter + 1);
         errorwarning.Text = line;
-        errorwarning.PreContext = "";
-        errorwarning.PostContext = "";
+        errorwarning.PreContext.clear();
+        errorwarning.PostContext.clear();
 
         // Copy pre-context to report
         for (std::string const& pc : this->PreContext) {

Source/CTest/cmCTestCoverageHandler.cxx

@@ -1049,7 +1049,7 @@ int cmCTestCoverageHandler::HandleGCovCoverage(
           break;
         }
 
-        actualSourceFile = "";
+        actualSourceFile.clear();
         sourceFile = st1re1.match(2);
       } else if (st1re2.find(line.c_str())) {
         if (gcovStyle == 0) {
@@ -1074,7 +1074,7 @@ int cmCTestCoverageHandler::HandleGCovCoverage(
           break;
         }
 
-        actualSourceFile = "";
+        actualSourceFile.clear();
         sourceFile = st2re1.match(1);
       } else if (st2re2.find(line.c_str())) {
         if (gcovStyle == 0) {
@@ -1216,11 +1216,11 @@ int cmCTestCoverageHandler::HandleGCovCoverage(
           }
         }
 
-        actualSourceFile = "";
+        actualSourceFile.clear();
       }
 
       if (!sourceFile.empty() && actualSourceFile.empty()) {
-        gcovFile = "";
+        gcovFile.clear();
 
         // Is it in the source dir or the binary dir?
         //
@@ -1514,7 +1514,7 @@ int cmCTestCoverageHandler::HandleLCovCoverage(
             }
           }
 
-          actualSourceFile = "";
+          actualSourceFile.clear();
         }
       }
     }

Source/CTest/cmCTestCurl.cxx

@@ -109,7 +109,7 @@ bool cmCTestCurl::UploadFile(std::string const& local_file,
                              std::string const& url, std::string const& fields,
                              std::string& response)
 {
-  response = "";
+  response.clear();
   if (!this->InitCurl()) {
     cmCTestLog(this->CTest, ERROR_MESSAGE, "Initialization of curl failed");
     return false;
@@ -185,7 +185,7 @@ bool cmCTestCurl::UploadFile(std::string const& local_file,
 bool cmCTestCurl::HttpRequest(std::string const& url,
                               std::string const& fields, std::string& response)
 {
-  response = "";
+  response.clear();
   cmCTestOptionalLog(this->CTest, DEBUG, "HttpRequest\n"
                        << "url: " << url << "\n"
                        << "fields " << fields << "\n",
@@ -240,10 +240,10 @@ bool cmCTestCurl::HttpRequest(std::string const& url,
 
 void cmCTestCurl::SetProxyType()
 {
-  this->HTTPProxy = "";
+  this->HTTPProxy.clear();
   // this is the default
   this->HTTPProxyType = CURLPROXY_HTTP;
-  this->HTTPProxyAuth = "";
+  this->HTTPProxyAuth.clear();
   if (cmSystemTools::GetEnv("HTTP_PROXY", this->HTTPProxy)) {
     std::string port;
     if (cmSystemTools::GetEnv("HTTP_PROXY_PORT", port)) {

Source/CTest/cmCTestHG.cxx

@@ -250,7 +250,7 @@ private:
         currPath += i;
       } else {
         output.push_back(currPath);
-        currPath = "";
+        currPath.clear();
       }
     }
     output.push_back(currPath);

Source/CTest/cmCTestMemCheckHandler.cxx

@@ -122,11 +122,11 @@ void cmCTestMemCheckHandler::Initialize()
   this->LogWithPID = false;
   this->CustomMaximumPassedTestOutputSize = 0;
   this->CustomMaximumFailedTestOutputSize = 0;
-  this->MemoryTester = "";
+  this->MemoryTester.clear();
   this->MemoryTesterDynamicOptions.clear();
   this->MemoryTesterOptions.clear();
   this->MemoryTesterStyle = UNKNOWN;
-  this->MemoryTesterOutputFile = "";
+  this->MemoryTesterOutputFile.clear();
   this->DefectCount = 0;
 }
 
@@ -417,8 +417,8 @@ void cmCTestMemCheckHandler::GenerateDartOutput(cmXMLWriter& xml)
 
 bool cmCTestMemCheckHandler::InitializeMemoryChecking()
 {
-  this->MemoryTesterEnvironmentVariable = "";
-  this->MemoryTester = "";
+  this->MemoryTesterEnvironmentVariable.clear();
+  this->MemoryTester.clear();
   // Setup the command
   if (cmSystemTools::FileExists(
         this->CTest->GetCTestConfiguration("MemoryCheckCommand").c_str())) {
@@ -725,7 +725,7 @@ bool cmCTestMemCheckHandler::ProcessMemCheckSanitizerOutput(
   std::vector<std::string> lines;
   cmSystemTools::Split(str.c_str(), lines);
   std::ostringstream ostr;
-  log = "";
+  log.clear();
   for (std::string const& l : lines) {
     std::string resultFound;
     if (leakWarning.find(l)) {
@@ -755,7 +755,7 @@ bool cmCTestMemCheckHandler::ProcessMemCheckPurifyOutput(
   std::vector<std::string> lines;
   cmSystemTools::Split(str.c_str(), lines);
   std::ostringstream ostr;
-  log = "";
+  log.clear();
 
   cmsys::RegularExpression pfW("^\\[[WEI]\\] ([A-Z][A-Z][A-Z][A-Z]*): ");
 
@@ -805,7 +805,7 @@ bool cmCTestMemCheckHandler::ProcessMemCheckValgrindOutput(
   std::string::size_type cc;
 
   std::ostringstream ostr;
-  log = "";
+  log.clear();
 
   int defects = 0;
 
@@ -928,7 +928,7 @@ bool cmCTestMemCheckHandler::ProcessMemCheckValgrindOutput(
 bool cmCTestMemCheckHandler::ProcessMemCheckBoundsCheckerOutput(
   const std::string& str, std::string& log, std::vector<int>& results)
 {
-  log = "";
+  log.clear();
   double sttime = cmSystemTools::GetTime();
   std::vector<std::string> lines;
   cmSystemTools::Split(str.c_str(), lines);
@@ -1079,7 +1079,7 @@ void cmCTestMemCheckHandler::TestOutputFileNames(
     if (g.GetFiles().empty()) {
       std::string log = "Cannot find memory tester output file: " + ofile;
       cmCTestLog(this->CTest, ERROR_MESSAGE, log << std::endl);
-      ofile = "";
+      ofile.clear();
     } else {
       files = g.GetFiles();
       return;
@@ -1087,7 +1087,7 @@ void cmCTestMemCheckHandler::TestOutputFileNames(
   } else if (!cmSystemTools::FileExists(ofile.c_str())) {
     std::string log = "Cannot find memory tester output file: " + ofile;
     cmCTestLog(this->CTest, ERROR_MESSAGE, log << std::endl);
-    ofile = "";
+    ofile.clear();
   }
   files.push_back(ofile);
 }

Source/CTest/cmCTestRunTest.cxx

@@ -30,8 +30,8 @@ cmCTestRunTest::cmCTestRunTest(cmCTestTestHandler* handler)
   this->TestResult.Status = cmCTestTestHandler::NOT_RUN;
   this->TestResult.TestCount = 0;
   this->TestResult.Properties = nullptr;
-  this->ProcessOutput = "";
-  this->CompressedOutput = "";
+  this->ProcessOutput.clear();
+  this->CompressedOutput.clear();
   this->CompressionRatio = 2;
   this->StopTimePassed = false;
   this->NumberOfRunsLeft = 1; // default to 1 run of the test
@@ -426,7 +426,7 @@ bool cmCTestRunTest::StartTest(size_t total)
     this->TestResult.Path = this->TestProperties->Directory;
     this->TestProcess = new cmProcess;
     this->TestResult.Output = "Disabled";
-    this->TestResult.FullCommandLine = "";
+    this->TestResult.FullCommandLine.clear();
     return false;
   }
 
@@ -451,7 +451,7 @@ bool cmCTestRunTest::StartTest(size_t total)
     *this->TestHandler->LogFile << msg << std::endl;
     cmCTestLog(this->CTest, HANDLER_OUTPUT, msg << std::endl);
     this->TestResult.Output = msg;
-    this->TestResult.FullCommandLine = "";
+    this->TestResult.FullCommandLine.clear();
     this->TestResult.CompletionStatus = "Fixture dependency failed";
     this->TestResult.Status = cmCTestTestHandler::NOT_RUN;
     return false;
@@ -471,7 +471,7 @@ bool cmCTestRunTest::StartTest(size_t total)
     *this->TestHandler->LogFile << msg << std::endl;
     cmCTestLog(this->CTest, ERROR_MESSAGE, msg << std::endl);
     this->TestResult.Output = msg;
-    this->TestResult.FullCommandLine = "";
+    this->TestResult.FullCommandLine.clear();
     this->TestResult.CompletionStatus = "Missing Configuration";
     this->TestResult.Status = cmCTestTestHandler::NOT_RUN;
     return false;
@@ -487,7 +487,7 @@ bool cmCTestRunTest::StartTest(size_t total)
       cmCTestLog(this->CTest, ERROR_MESSAGE,
                  "Unable to find required file: " << file << std::endl);
       this->TestResult.Output = "Unable to find required file: " + file;
-      this->TestResult.FullCommandLine = "";
+      this->TestResult.FullCommandLine.clear();
       this->TestResult.CompletionStatus = "Required Files Missing";
       this->TestResult.Status = cmCTestTestHandler::NOT_RUN;
       return false;
@@ -503,7 +503,7 @@ bool cmCTestRunTest::StartTest(size_t total)
     cmCTestLog(this->CTest, ERROR_MESSAGE,
                "Unable to find executable: " << args[1] << std::endl);
     this->TestResult.Output = "Unable to find executable: " + args[1];
-    this->TestResult.FullCommandLine = "";
+    this->TestResult.FullCommandLine.clear();
     this->TestResult.CompletionStatus = "Unable to find executable";
     this->TestResult.Status = cmCTestTestHandler::NOT_RUN;
     return false;

Source/CTest/cmCTestScriptHandler.cxx

@@ -93,18 +93,18 @@ void cmCTestScriptHandler::Initialize()
   this->EmptyBinDir = false;
   this->EmptyBinDirOnce = false;
 
-  this->SourceDir = "";
-  this->BinaryDir = "";
-  this->BackupSourceDir = "";
-  this->BackupBinaryDir = "";
-  this->CTestRoot = "";
-  this->CVSCheckOut = "";
-  this->CTestCmd = "";
-  this->UpdateCmd = "";
-  this->CTestEnv = "";
-  this->InitialCache = "";
-  this->CMakeCmd = "";
-  this->CMOutFile = "";
+  this->SourceDir.clear();
+  this->BinaryDir.clear();
+  this->BackupSourceDir.clear();
+  this->BackupBinaryDir.clear();
+  this->CTestRoot.clear();
+  this->CVSCheckOut.clear();
+  this->CTestCmd.clear();
+  this->UpdateCmd.clear();
+  this->CTestEnv.clear();
+  this->InitialCache.clear();
+  this->CMakeCmd.clear();
+  this->CMOutFile.clear();
   this->ExtraUpdates.clear();
 
   this->MinimumInterval = 20 * 60;
@@ -593,7 +593,7 @@ int cmCTestScriptHandler::CheckOutSourceDir()
   if (!cmSystemTools::FileExists(this->SourceDir.c_str()) &&
       !this->CVSCheckOut.empty()) {
     // we must now checkout the src dir
-    output = "";
+    output.clear();
     cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
                "Run cvs: " << this->CVSCheckOut << std::endl);
     res = cmSystemTools::RunSingleCommand(
@@ -659,7 +659,7 @@ int cmCTestScriptHandler::PerformExtraUpdates()
       std::string fullCommand = command;
       fullCommand += " update ";
       fullCommand += cvsArgs[1];
-      output = "";
+      output.clear();
       retVal = 0;
       cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
                  "Run Update: " << fullCommand << std::endl);
@@ -762,7 +762,7 @@ int cmCTestScriptHandler::RunConfigurationDashboard()
     command = this->CMakeCmd;
     command += " \"";
     command += this->SourceDir;
-    output = "";
+    output.clear();
     command += "\"";
     retVal = 0;
     cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
@@ -802,7 +802,7 @@ int cmCTestScriptHandler::RunConfigurationDashboard()
   // for each variable/argument do a putenv
   for (std::string const& ctestCommand : ctestCommands) {
     command = ctestCommand;
-    output = "";
+    output.clear();
     retVal = 0;
     cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
                "Run ctest command: " << command << std::endl);

Source/CTest/cmCTestSubmitHandler.cxx

@@ -140,10 +140,10 @@ void cmCTestSubmitHandler::Initialize()
   this->HasWarnings = false;
   this->HasErrors = false;
   this->Superclass::Initialize();
-  this->HTTPProxy = "";
+  this->HTTPProxy.clear();
   this->HTTPProxyType = 0;
-  this->HTTPProxyAuth = "";
-  this->FTPProxy = "";
+  this->HTTPProxyAuth.clear();
+  this->FTPProxy.clear();
   this->FTPProxyType = 0;
   this->LogFile = nullptr;
   this->Files.clear();

Source/CTest/cmCTestTestHandler.cxx

@@ -351,8 +351,8 @@ void cmCTestTestHandler::Initialize()
   this->TestResults.clear();
 
   this->CustomTestsIgnore.clear();
-  this->StartTest = "";
-  this->EndTest = "";
+  this->StartTest.clear();
+  this->EndTest.clear();
 
   this->CustomPreTest.clear();
   this->CustomPostTest.clear();
@@ -368,13 +368,13 @@ void cmCTestTestHandler::Initialize()
   this->UseExcludeRegExpFirst = false;
   this->IncludeLabelRegularExpression = "";
   this->ExcludeLabelRegularExpression = "";
-  this->IncludeRegExp = "";
-  this->ExcludeRegExp = "";
+  this->IncludeRegExp.clear();
+  this->ExcludeRegExp.clear();
   this->ExcludeFixtureRegExp.clear();
   this->ExcludeFixtureSetupRegExp.clear();
   this->ExcludeFixtureCleanupRegExp.clear();
 
-  TestsToRunString = "";
+  TestsToRunString.clear();
   this->UseUnion = false;
   this->TestList.clear();
 }
@@ -1595,9 +1595,9 @@ std::string cmCTestTestHandler::FindExecutable(
   // if everything else failed, check the users path, but only if a full path
   // wasn't specified
   if (fullPath.empty() && filepath.empty()) {
-    std::string path = cmSystemTools::FindProgram(filename.c_str());
+    std::string const path = cmSystemTools::FindProgram(filename.c_str());
     if (path != "") {
-      resultingConfig = "";
+      resultingConfig.clear();
       return path;
     }
   }

Source/CTest/cmCTestUpdateHandler.cxx

@@ -39,7 +39,7 @@ cmCTestUpdateHandler::cmCTestUpdateHandler()
 void cmCTestUpdateHandler::Initialize()
 {
   this->Superclass::Initialize();
-  this->UpdateCommand = "";
+  this->UpdateCommand.clear();
   this->UpdateType = e_CVS;
 }
 

Source/CTest/cmParseCacheCoverage.cxx

@@ -146,7 +146,7 @@ bool cmParseCacheCoverage::ReadCMCovFile(const char* file)
         cmCTestLog(this->CTest, ERROR_MESSAGE,
                    "Could not find mumps file for routine: " << routine
                                                              << "\n");
-        filepath = "";
+        filepath.clear();
         continue; // move to next line
       }
     }
@@ -154,8 +154,8 @@ bool cmParseCacheCoverage::ReadCMCovFile(const char* file)
     else {
       // Totals in arg 0 marks the end of a routine
       if (separateLine[0].substr(0, 6) == "Totals") {