stringapi: Pass configuration names as strings

Source/CPack/cmCPackGenerator.cxx

@@ -623,7 +623,8 @@ int cmCPackGenerator::InstallProjectViaInstallCMakeProjects(
         componentsVector.push_back(installComponent);
         }
 
-      const char* buildConfig = this->GetOption("CPACK_BUILD_CONFIG");
+      const char* buildConfigCstr = this->GetOption("CPACK_BUILD_CONFIG");
+      std::string buildConfig = buildConfigCstr ? buildConfigCstr : "";
       cmGlobalGenerator* globalGenerator
         = this->MakefileMap->GetCMakeInstance()->CreateGlobalGenerator(
           cmakeGenerator);
@@ -822,9 +823,9 @@ int cmCPackGenerator::InstallProjectViaInstallCMakeProjects(
                         << "'" << std::endl);
           }
 
-        if ( buildConfig && *buildConfig )
+        if (!buildConfig.empty())
           {
-          mf->AddDefinition("BUILD_TYPE", buildConfig);
+          mf->AddDefinition("BUILD_TYPE", buildConfig.c_str());
           }
         std::string installComponentLowerCase
           = cmSystemTools::LowerCase(installComponent);

Source/cmComputeLinkDepends.cxx

@@ -172,7 +172,7 @@ satisfy dependencies.
 
 //----------------------------------------------------------------------------
 cmComputeLinkDepends
-::cmComputeLinkDepends(cmTarget const* target, const char* config,
+::cmComputeLinkDepends(cmTarget const* target, const std::string& config,
                        cmTarget const* head)
 {
   // Store context information.
@@ -184,7 +184,8 @@ cmComputeLinkDepends
   this->CMakeInstance = this->GlobalGenerator->GetCMakeInstance();
 
   // The configuration being linked.
-  this->Config = (config && *config)? config : 0;
+  this->HasConfig = !config.empty();
+  this->Config = (this->HasConfig)? config : std::string();
   this->LinkType = this->Target->ComputeLinkType(this->Config);
 
   // Enable debug mode if requested.
@@ -255,7 +256,7 @@ cmComputeLinkDepends::Compute()
             "---------------------------------------\n");
     fprintf(stderr, "Link dependency analysis for target %s, config %s\n",
             this->Target->GetName().c_str(),
-            this->Config?this->Config:"noconfig");
+            this->HasConfig?this->Config.c_str():"noconfig");
     this->DisplayConstraintGraph();
     }
 

Source/cmComputeLinkDepends.h

@@ -32,7 +32,7 @@ class cmake;
 class cmComputeLinkDepends
 {
 public:
-  cmComputeLinkDepends(cmTarget const* target, const char* config,
+  cmComputeLinkDepends(cmTarget const* target, const std::string& config,
                        cmTarget const* head);
   ~cmComputeLinkDepends();
 
@@ -68,7 +68,8 @@ private:
   bool DebugMode;
 
   // Configuration information.
-  const char* Config;
+  bool HasConfig;
+  std::string Config;
   cmTarget::LinkLibraryType LinkType;
 
   // Output information.

Source/cmComputeLinkInformation.cxx

@@ -239,7 +239,7 @@ because this need be done only for shared libraries without soname-s.
 
 //----------------------------------------------------------------------------
 cmComputeLinkInformation
-::cmComputeLinkInformation(cmTarget const* target, const char* config,
+::cmComputeLinkInformation(cmTarget const* target, const std::string& config,
                            cmTarget const* headTarget)
 {
   // Store context information.
@@ -505,7 +505,8 @@ bool cmComputeLinkInformation::Compute()
     }
 
   // Compute the ordered link line items.
-  cmComputeLinkDepends cld(this->Target, this->Config, this->HeadTarget);
+  cmComputeLinkDepends cld(this->Target, this->Config.c_str(),
+                           this->HeadTarget);
   cld.SetOldLinkDirMode(this->OldLinkDirMode);
   cmComputeLinkDepends::EntryVector const& linkEntries = cld.Compute();
 
@@ -624,7 +625,7 @@ void cmComputeLinkInformation::AddItem(std::string const& item,
                                        cmTarget const* tgt)
 {
   // Compute the proper name to use to link this library.
-  const char* config = this->Config;
+  const std::string& config = this->Config;
   bool impexe = (tgt && tgt->IsExecutableWithExports());
   if(impexe && !this->UseImportLibrary && !this->LoaderFlag)
     {

Source/cmComputeLinkInformation.h

@@ -29,7 +29,7 @@ class cmOrderDirectories;
 class cmComputeLinkInformation
 {
 public:
-  cmComputeLinkInformation(cmTarget const* target, const char* config,
+  cmComputeLinkInformation(cmTarget const* target, const std::string& config,
                            cmTarget const* headTarget);
   ~cmComputeLinkInformation();
   bool Compute();
@@ -82,7 +82,7 @@ private:
   cmake* CMakeInstance;
 
   // Configuration information.
-  const char* Config;
+  std::string Config;
   std::string LinkLanguage;
   bool LinkDependsNoShared;
 

Source/cmComputeTargetDepends.cxx

@@ -214,7 +214,7 @@ void cmComputeTargetDepends::CollectTargetDepends(int depender_index)
   std::set<std::string> emitted;
   {
   std::vector<std::string> tlibs;
-  depender->GetDirectLinkLibraries(0, tlibs, depender);
+  depender->GetDirectLinkLibraries("", tlibs, depender);
   // A target should not depend on itself.
   emitted.insert(depender->GetName());
   for(std::vector<std::string>::const_iterator lib = tlibs.begin();
@@ -274,7 +274,7 @@ void cmComputeTargetDepends::CollectTargetDepends(int depender_index)
 //----------------------------------------------------------------------------
 void cmComputeTargetDepends::AddInterfaceDepends(int depender_index,
                                                  cmTarget const* dependee,
-                                                 const char *config,
+                                                 const std::string& config,
                                                std::set<std::string> &emitted)
 {
   cmTarget const* depender = this->Targets[depender_index];
@@ -317,7 +317,7 @@ void cmComputeTargetDepends::AddInterfaceDepends(int depender_index,
 
   if(dependee)
     {
-    this->AddInterfaceDepends(depender_index, dependee, 0, emitted);
+    this->AddInterfaceDepends(depender_index, dependee, "", emitted);
     std::vector<std::string> configs;
     depender->GetMakefile()->GetConfigurations(configs);
     for (std::vector<std::string>::const_iterator it = configs.begin();

Source/cmComputeTargetDepends.h

@@ -55,7 +55,7 @@ private:
                            const std::string& dependee_name,
                            bool linking, std::set<std::string> &emitted);
   void AddInterfaceDepends(int depender_index, cmTarget const* dependee,
-                           const char *config,
+                           const std::string& config,
                            std::set<std::string> &emitted);
   cmGlobalGenerator* GlobalGenerator;
   bool DebugMode;

Source/cmCoreTryCompile.cxx

@@ -357,7 +357,7 @@ int cmCoreTryCompile::TryCompileCode(std::vector<std::string> const& argv)
       cmExportTryCompileFileGenerator tcfg;
       tcfg.SetExportFile((this->BinaryDirectory + fname).c_str());
       tcfg.SetExports(targets);
-      tcfg.SetConfig(this->Makefile->GetDefinition(
+      tcfg.SetConfig(this->Makefile->GetSafeDefinition(
                                           "CMAKE_TRY_COMPILE_CONFIGURATION"));
 
       if(!tcfg.GenerateImportFile())

Source/cmCustomCommandGenerator.cxx

@@ -18,7 +18,7 @@
 
 //----------------------------------------------------------------------------
 cmCustomCommandGenerator::cmCustomCommandGenerator(
-  cmCustomCommand const& cc, const char* config, cmMakefile* mf):
+  cmCustomCommand const& cc, const std::string& config, cmMakefile* mf):
   CC(cc), Config(config), Makefile(mf), LG(mf->GetLocalGenerator()),
   OldStyle(cc.GetEscapeOldStyle()), MakeVars(cc.GetEscapeAllowMakeVars()),
   GE(new cmGeneratorExpression(cc.GetBacktrace()))

Source/cmCustomCommandGenerator.h

@@ -22,14 +22,15 @@ class cmGeneratorExpression;
 class cmCustomCommandGenerator
 {
   cmCustomCommand const& CC;
-  const char* Config;
+  std::string Config;
   cmMakefile* Makefile;
   cmLocalGenerator* LG;
   bool OldStyle;
   bool MakeVars;
   cmGeneratorExpression* GE;
 public:
-  cmCustomCommandGenerator(cmCustomCommand const& cc, const char* config,
+  cmCustomCommandGenerator(cmCustomCommand const& cc,
+                           const std::string& config,
                            cmMakefile* mf);
   ~cmCustomCommandGenerator();
   unsigned int GetNumberOfCommands() const;

Source/cmExportBuildFileGenerator.cxx

@@ -118,8 +118,9 @@ bool cmExportBuildFileGenerator::GenerateMainFile(std::ostream& os)
 void
 cmExportBuildFileGenerator
 ::GenerateImportTargetsConfig(std::ostream& os,
-                              const char* config, std::string const& suffix,
-                            std::vector<std::string> &missingTargets)
+                              const std::string& config,
+                              std::string const& suffix,
+                              std::vector<std::string> &missingTargets)
 {
   for(std::vector<cmTarget*>::const_iterator
         tei = this->Exports.begin();
@@ -166,7 +167,8 @@ void cmExportBuildFileGenerator::SetExportSet(cmExportSet *exportSet)
 //----------------------------------------------------------------------------
 void
 cmExportBuildFileGenerator
-::SetImportLocationProperty(const char* config, std::string const& suffix,
+::SetImportLocationProperty(const std::string& config,
+                            std::string const& suffix,
                             cmTarget* target, ImportPropertyMap& properties)
 {
   // Get the makefile in which to lookup target information.

Source/cmExportBuildFileGenerator.h

@@ -52,7 +52,7 @@ protected:
   // Implement virtual methods from the superclass.
   virtual bool GenerateMainFile(std::ostream& os);
   virtual void GenerateImportTargetsConfig(std::ostream& os,
-                                           const char* config,
+                                           const std::string& config,
                                            std::string const& suffix,
                             std::vector<std::string> &missingTargets);
   virtual void HandleMissingTarget(std::string& link_libs,
@@ -66,7 +66,7 @@ protected:
                                   int occurrences);
 
   /** Fill in properties indicating built file locations.  */
-  void SetImportLocationProperty(const char* config,
+  void SetImportLocationProperty(const std::string& config,
                                  std::string const& suffix,
                                  cmTarget* target,
                                  ImportPropertyMap& properties);

Source/cmExportFileGenerator.cxx

@@ -35,7 +35,7 @@ cmExportFileGenerator::cmExportFileGenerator()
 }
 
 //----------------------------------------------------------------------------
-void cmExportFileGenerator::AddConfiguration(const char* config)
+void cmExportFileGenerator::AddConfiguration(const std::string& config)
 {
   this->Configurations.push_back(config);
 }
@@ -117,12 +117,12 @@ bool cmExportFileGenerator::GenerateImportFile()
 
 //----------------------------------------------------------------------------
 void cmExportFileGenerator::GenerateImportConfig(std::ostream& os,
-                                    const char* config,
+                                    const std::string& config,
                                     std::vector<std::string> &missingTargets)
 {
   // Construct the property configuration suffix.
   std::string suffix = "_";
-  if(config && *config)
+  if(!config.empty())
     {
     suffix += cmSystemTools::UpperCase(config);
     }
@@ -345,7 +345,7 @@ void cmExportFileGenerator::PopulateIncludeDirectoriesInterface(
                                             true);
   this->ReplaceInstallPrefix(dirs);
   cmsys::auto_ptr<cmCompiledGeneratorExpression> cge = ge.Parse(dirs);
-  std::string exportDirs = cge->Evaluate(target->GetMakefile(), 0,
+  std::string exportDirs = cge->Evaluate(target->GetMakefile(), "",
                                          false, target);
 
   if (cge->GetHadContextSensitiveCondition())
@@ -426,7 +426,7 @@ void getPropertyContents(cmTarget const* tgt, const std::string& prop,
 //----------------------------------------------------------------------------
 void getCompatibleInterfaceProperties(cmTarget *target,
                                       std::set<std::string> &ifaceProperties,
-                                      const char *config)
+                                      const std::string& config)
 {
   cmComputeLinkInformation *info = target->GetLinkInformation(config);
 
@@ -490,7 +490,7 @@ void cmExportFileGenerator::PopulateCompatibleInterfaceProperties(
 
   if (target->GetType() != cmTarget::INTERFACE_LIBRARY)
     {
-    getCompatibleInterfaceProperties(target, ifaceProperties, 0);
+    getCompatibleInterfaceProperties(target, ifaceProperties, "");
 
     std::vector<std::string> configNames;
     target->GetMakefile()->GetConfigurations(configNames);
@@ -687,7 +687,7 @@ cmExportFileGenerator::ReplaceInstallPrefix(std::string &)
 //----------------------------------------------------------------------------
 void
 cmExportFileGenerator
-::SetImportLinkInterface(const char* config, std::string const& suffix,
+::SetImportLinkInterface(const std::string& config, std::string const& suffix,
                     cmGeneratorExpression::PreprocessContext preprocessRule,
                     cmTarget* target, ImportPropertyMap& properties,
                     std::vector<std::string>& missingTargets)
@@ -762,7 +762,8 @@ cmExportFileGenerator
 //----------------------------------------------------------------------------
 void
 cmExportFileGenerator
-::SetImportDetailProperties(const char* config, std::string const& suffix,
+::SetImportDetailProperties(const std::string& config,
+                            std::string const& suffix,
                             cmTarget* target, ImportPropertyMap& properties,
                             std::vector<std::string>& missingTargets
                            )
@@ -864,11 +865,11 @@ cmExportFileGenerator
 
 //----------------------------------------------------------------------------
 void cmExportFileGenerator::GenerateImportHeaderCode(std::ostream& os,
-                                                     const char* config)
+                                                    const std::string& config)
 {
   os << "#----------------------------------------------------------------\n"
      << "# Generated CMake target import file";
-  if(config)
+  if(!config.empty())
     {
     os << " for configuration \"" << config << "\".\n";
     }
@@ -999,7 +1000,7 @@ cmExportFileGenerator
 //----------------------------------------------------------------------------
 void
 cmExportFileGenerator
-::GenerateImportPropertyCode(std::ostream& os, const char* config,
+::GenerateImportPropertyCode(std::ostream& os, const std::string& config,
                              cmTarget const* target,
                              ImportPropertyMap const& properties)
 {
@@ -1013,7 +1014,7 @@ cmExportFileGenerator
      << config << "\"\n";
   os << "set_property(TARGET " << targetName
      << " APPEND PROPERTY IMPORTED_CONFIGURATIONS ";
-  if(config && *config)
+  if(!config.empty())
     {
     os << cmSystemTools::UpperCase(config);
     }

Source/cmExportFileGenerator.h

@@ -56,7 +56,7 @@ public:
   void SetExportOld(bool exportOld) { this->ExportOld = exportOld; }
 
   /** Add a configuration to be exported.  */
-  void AddConfiguration(const char* config);
+  void AddConfiguration(const std::string& config);
 
   /** Actually generate the export file.  Returns whether there was an
       error.  */
@@ -67,15 +67,16 @@ protected:
 
   // Generate per-configuration target information to the given output
   // stream.
-  void GenerateImportConfig(std::ostream& os, const char* config,
+  void GenerateImportConfig(std::ostream& os, const std::string& config,
                             std::vector<std::string> &missingTargets);
 
   // Methods to implement export file code generation.
-  void GenerateImportHeaderCode(std::ostream& os, const char* config = 0);
+  void GenerateImportHeaderCode(std::ostream& os,
+                                const std::string& config = "");
   void GenerateImportFooterCode(std::ostream& os);
   void GenerateImportVersionCode(std::ostream& os);
   void GenerateImportTargetCode(std::ostream& os, cmTarget const* target);
-  void GenerateImportPropertyCode(std::ostream& os, const char* config,
+  void GenerateImportPropertyCode(std::ostream& os, const std::string& config,
                                   cmTarget const* target,
                                   ImportPropertyMap const& properties);
   void GenerateImportedFileChecksCode(std::ostream& os, cmTarget* target,
@@ -90,7 +91,7 @@ protected:
 
   // Collect properties with detailed information about targets beyond
   // their location on disk.
-  void SetImportDetailProperties(const char* config,
+  void SetImportDetailProperties(const std::string& config,
                                  std::string const& suffix, cmTarget* target,
                                  ImportPropertyMap& properties,
                                  std::vector<std::string>& missingTargets);
@@ -105,7 +106,7 @@ protected:
 
   /** Each subclass knows where the target files are located.  */
   virtual void GenerateImportTargetsConfig(std::ostream& os,
-                                           const char* config,
+                                           const std::string& config,
                                            std::string const& suffix,
                             std::vector<std::string> &missingTargets) = 0;
 
@@ -137,7 +138,8 @@ protected:
                       ImportPropertyMap &properties,
                       std::vector<std::string> &missingTargets);
 
-  void SetImportLinkInterface(const char* config, std::string const& suffix,
+  void SetImportLinkInterface(const std::string& config,
+                    std::string const& suffix,
                     cmGeneratorExpression::PreprocessContext preprocessRule,
                     cmTarget* target, ImportPropertyMap& properties,
                     std::vector<std::string>& missingTargets);

Source/cmExportInstallFileGenerator.cxx

@@ -240,7 +240,8 @@ cmExportInstallFileGenerator::ReplaceInstallPrefix(std::string &input)
 
 //----------------------------------------------------------------------------
 bool
-cmExportInstallFileGenerator::GenerateImportFileConfig(const char* config,
+cmExportInstallFileGenerator::GenerateImportFileConfig(
+                                    const std::string& config,
                                     std::vector<std::string> &missingTargets)
 {
   // Skip configurations not enabled for this export.
@@ -254,7 +255,7 @@ cmExportInstallFileGenerator::GenerateImportFileConfig(const char* config,
   fileName += "/";
   fileName += this->FileBase;
   fileName += "-";
-  if(config && *config)
+  if(!config.empty())
     {
     fileName += cmSystemTools::LowerCase(config);
     }
@@ -296,7 +297,8 @@ cmExportInstallFileGenerator::GenerateImportFileConfig(const char* config,
 void
 cmExportInstallFileGenerator
 ::GenerateImportTargetsConfig(std::ostream& os,
-                              const char* config, std::string const& suffix,
+                              const std::string& config,
+                              std::string const& suffix,
                               std::vector<std::string> &missingTargets)
 {
   // Add each target in the set to the export.
@@ -355,7 +357,8 @@ cmExportInstallFileGenerator
 //----------------------------------------------------------------------------
 void
 cmExportInstallFileGenerator
-::SetImportLocationProperty(const char* config, std::string const& suffix,
+::SetImportLocationProperty(const std::string& config,
+                            std::string const& suffix,
                             cmInstallTargetGenerator* itgen,
                             ImportPropertyMap& properties,
                             std::set<std::string>& importedLocations

Source/cmExportInstallFileGenerator.h

@@ -52,7 +52,7 @@ protected:
   // Implement virtual methods from the superclass.
   virtual bool GenerateMainFile(std::ostream& os);
   virtual void GenerateImportTargetsConfig(std::ostream& os,
-                                           const char* config,
+                                           const std::string& config,
                                            std::string const& suffix,
                             std::vector<std::string> &missingTargets);
   virtual void HandleMissingTarget(std::string& link_libs,
@@ -72,11 +72,11 @@ protected:
 
 
   /** Generate a per-configuration file for the targets.  */
-  bool GenerateImportFileConfig(const char* config,
+  bool GenerateImportFileConfig(const std::string& config,
                             std::vector<std::string> &missingTargets);
 
   /** Fill in properties indicating installed file locations.  */
-  void SetImportLocationProperty(const char* config,
+  void SetImportLocationProperty(const std::string& config,
                                  std::string const& suffix,
                                  cmInstallTargetGenerator* itgen,
                                  ImportPropertyMap& properties,

Source/cmExportTryCompileFileGenerator.h

@@ -23,14 +23,14 @@ public:
   /** Set the list of targets to export.  */
   void SetExports(const std::vector<cmTarget const*> &exports)
     { this->Exports = exports; }
-  void SetConfig(const char *config) { this->Config = config; }
+  void SetConfig(const std::string& config) { this->Config = config; }
 protected:
 
   // Implement virtual methods from the superclass.
   virtual bool GenerateMainFile(std::ostream& os);
 
   virtual void GenerateImportTargetsConfig(std::ostream&,
-                                           const char*,
+                                           const std::string&,
                                            std::string const&,
                             std::vector<std::string>&) {}
   virtual void HandleMissingTarget(std::string&,
@@ -51,7 +51,7 @@ private:
 
 
   std::vector<cmTarget const*> Exports;
-  const char *Config;
+  std::string Config;
 };
 
 #endif

Source/cmExtraSublimeTextGenerator.cxx

@@ -375,7 +375,7 @@ cmExtraSublimeTextGenerator::ComputeFlagsForObject(cmSourceFile* source,
    {
    language = "C";
    }
-  const char* config = makefile->GetSafeDefinition("CMAKE_BUILD_TYPE");
+  const std::string& config = makefile->GetSafeDefinition("CMAKE_BUILD_TYPE");
   // Add language-specific flags.
   lg->AddLanguageFlags(flags, language, config);
 
@@ -425,7 +425,7 @@ ComputeDefines(cmSourceFile *source, cmLocalGenerator* lg, cmTarget *target,
   std::set<std::string> defines;
   cmMakefile *makefile = lg->GetMakefile();
   const std::string& language = source->GetLanguage();
-  const char* config = makefile->GetSafeDefinition("CMAKE_BUILD_TYPE");
+  const std::string& config = makefile->GetSafeDefinition("CMAKE_BUILD_TYPE");
 
   // Add the export symbol definition for shared library objects.
   if(const char* exportMacro = target->GetExportMacro())

Source/cmGeneratorExpression.cxx

@@ -52,7 +52,7 @@ cmGeneratorExpression::~cmGeneratorExpression()
 
 //----------------------------------------------------------------------------
 const char *cmCompiledGeneratorExpression::Evaluate(
-  cmMakefile* mf, const char* config, bool quiet,
+  cmMakefile* mf, const std::string& config, bool quiet,
   cmTarget const* headTarget,
   cmGeneratorExpressionDAGChecker *dagChecker) const
 {
@@ -66,7 +66,7 @@ const char *cmCompiledGeneratorExpression::Evaluate(
 
 //----------------------------------------------------------------------------
 const char *cmCompiledGeneratorExpression::Evaluate(
-  cmMakefile* mf, const char* config, bool quiet,
+  cmMakefile* mf, const std::string& config, bool quiet,
   cmTarget const* headTarget,
   cmTarget const* currentTarget,
   cmGeneratorExpressionDAGChecker *dagChecker) const

Source/cmGeneratorExpression.h

@@ -78,12 +78,12 @@ private:
 class cmCompiledGeneratorExpression
 {
 public:
-  const char* Evaluate(cmMakefile* mf, const char* config,
+  const char* Evaluate(cmMakefile* mf, const std::string& config,
                        bool quiet = false,
                        cmTarget const* headTarget = 0,
                        cmTarget const* currentTarget = 0,
                        cmGeneratorExpressionDAGChecker *dagChecker = 0) const;
-  const char* Evaluate(cmMakefile* mf, const char* config,
+  const char* Evaluate(cmMakefile* mf, const std::string& config,
                        bool quiet,
                        cmTarget const* headTarget,
                        cmGeneratorExpressionDAGChecker *dagChecker) const;

Source/cmGeneratorExpressionEvaluationFile.cxx

@@ -33,7 +33,7 @@ cmGeneratorExpressionEvaluationFile::cmGeneratorExpressionEvaluationFile(
 }
 
 //----------------------------------------------------------------------------
-void cmGeneratorExpressionEvaluationFile::Generate(const char *config,
+void cmGeneratorExpressionEvaluationFile::Generate(const std::string& config,
               cmCompiledGeneratorExpression* inputExpression,
               std::map<std::string, std::string> &outputFiles)
 {
@@ -135,7 +135,7 @@ void cmGeneratorExpressionEvaluationFile::Generate()
 
   if (allConfigs.empty())
     {
-    this->Generate(0, inputExpression.get(), outputFiles);
+    this->Generate("", inputExpression.get(), outputFiles);
     }
   else
     {

Source/cmGeneratorExpressionEvaluationFile.h

@@ -32,7 +32,7 @@ public:
   std::vector<std::string> GetFiles() const { return this->Files; }
 
 private:
-  void Generate(const char *config,
+  void Generate(const std::string& config,
               cmCompiledGeneratorExpression* inputExpression,
               std::map<std::string, std::string> &outputFiles);
 

Source/cmGeneratorExpressionEvaluator.cxx

@@ -689,7 +689,7 @@ static const struct ConfigurationNode : public cmGeneratorExpressionNode
                        cmGeneratorExpressionDAGChecker *) const
   {
     context->HadContextSensitiveCondition = true;
-    return context->Config ? context->Config : "";
+    return context->Config;
   }
 } configurationNode;
 
@@ -718,13 +718,13 @@ static const struct ConfigurationTestNode : public cmGeneratorExpressionNode
       return std::string();
       }
     context->HadContextSensitiveCondition = true;
-    if (!context->Config)
+    if (context->Config.empty())
       {
       return parameters.front().empty() ? "1" : "0";