cmMakefile: Refactor API to better handle empty config values

22 files changed, 125 insertions, 132 deletions

diff --git a/Source/cmComputeTargetDepends.cxx b/Source/cmComputeTargetDepends.cxx
index 41f5346..6b4d110 100644
--- a/Source/cmComputeTargetDepends.cxx
+++ b/Source/cmComputeTargetDepends.cxx
@@ -196,7 +196,7 @@ void cmComputeTargetDepends::CollectTargetDepends(int depender_index)
     std::set<cmLinkItem> emitted;
 
     std::vector<std::string> const& configs =
-      depender->Makefile->GetGeneratorConfigs();
+      depender->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
     for (std::string const& it : configs) {
       cmLinkImplementation const* impl = depender->GetLinkImplementation(it);
 
diff --git a/Source/cmExportCommand.cxx b/Source/cmExportCommand.cxx
index 9f8a821..352eaf2 100644
--- a/Source/cmExportCommand.cxx
+++ b/Source/cmExportCommand.cxx
@@ -223,11 +223,9 @@ bool cmExportCommand(std::vector<std::string> const& args,
   ebfg->SetExportOld(arguments.ExportOld);
 
   // Compute the set of configurations exported.
-  std::vector<std::string> configurationTypes;
-  mf.GetConfigurations(configurationTypes);
-  if (configurationTypes.empty()) {
-    configurationTypes.emplace_back();
-  }
+  std::vector<std::string> configurationTypes =
+    mf.GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
+
   for (std::string const& ct : configurationTypes) {
     ebfg->AddConfiguration(ct);
   }
diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index 4d0e099..58aa391 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -567,8 +567,9 @@ void cmExportFileGenerator::PopulateCompatibleInterfaceProperties(
   if (gtarget->GetType() != cmStateEnums::INTERFACE_LIBRARY) {
     getCompatibleInterfaceProperties(gtarget, ifaceProperties, "");
 
-    std::vector<std::string> configNames;
-    gtarget->Target->GetMakefile()->GetConfigurations(configNames);
+    std::vector<std::string> configNames =
+      gtarget->Target->GetMakefile()->GetGeneratorConfigs(
+        cmMakefile::ExcludeEmptyConfig);
 
     for (std::string const& cn : configNames) {
       getCompatibleInterfaceProperties(gtarget, ifaceProperties, cn);
diff --git a/Source/cmFileAPICodemodel.cxx b/Source/cmFileAPICodemodel.cxx
index 21d9abb..ca1ed56 100644
--- a/Source/cmFileAPICodemodel.cxx
+++ b/Source/cmFileAPICodemodel.cxx
@@ -445,7 +445,7 @@ Json::Value Codemodel::DumpConfigurations()
   const auto& makefiles = gg->GetMakefiles();
   if (!makefiles.empty()) {
     std::vector<std::string> const& configs =
-      makefiles[0]->GetGeneratorConfigs();
+      makefiles[0]->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
     for (std::string const& config : configs) {
       configurations.append(this->DumpConfiguration(config));
     }
diff --git a/Source/cmGeneratorExpressionEvaluationFile.cxx b/Source/cmGeneratorExpressionEvaluationFile.cxx
index 9e8707d..1107adb 100644
--- a/Source/cmGeneratorExpressionEvaluationFile.cxx
+++ b/Source/cmGeneratorExpressionEvaluationFile.cxx
@@ -157,12 +157,8 @@ void cmGeneratorExpressionEvaluationFile::Generate(cmLocalGenerator* lg)
 
   std::map<std::string, std::string> outputFiles;
 
-  std::vector<std::string> allConfigs;
-  lg->GetMakefile()->GetConfigurations(allConfigs);
-
-  if (allConfigs.empty()) {
-    allConfigs.emplace_back();
-  }
+  std::vector<std::string> allConfigs =
+    lg->GetMakefile()->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 
   std::vector<std::string> enabledLanguages;
   cmGlobalGenerator* gg = lg->GetGlobalGenerator();
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 992682f..962d97f 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -801,7 +801,8 @@ void cmGeneratorTarget::GetObjectSources(
 
 void cmGeneratorTarget::ComputeObjectMapping()
 {
-  auto const& configs = this->Makefile->GetGeneratorConfigs();
+  auto const& configs =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
   std::set<std::string> configSet(configs.begin(), configs.end());
   if (configSet == this->VisitedConfigsForObjects) {
     return;
@@ -1778,8 +1779,8 @@ cmGeneratorTarget::GetAllConfigSources() const
 
 void cmGeneratorTarget::ComputeAllConfigSources() const
 {
-  std::vector<std::string> configs;
-  this->Makefile->GetConfigurations(configs);
+  std::vector<std::string> configs =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 
   std::map<cmSourceFile const*, size_t> index;
 
@@ -2812,7 +2813,7 @@ cmTargetTraceDependencies::cmTargetTraceDependencies(cmGeneratorTarget* target)
   if (target->GetType() != cmStateEnums::INTERFACE_LIBRARY) {
     std::set<cmSourceFile*> emitted;
     std::vector<std::string> const& configs =
-      this->Makefile->GetGeneratorConfigs();
+      this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
     for (std::string const& c : configs) {
       std::vector<cmSourceFile*> sources;
       this->GeneratorTarget->GetSourceFiles(sources, c);
@@ -3023,7 +3024,7 @@ void cmTargetTraceDependencies::CheckCustomCommand(cmCustomCommand const& cc)
   // Queue the custom command dependencies.
   std::set<std::string> emitted;
   std::vector<std::string> const& configs =
-    this->Makefile->GetGeneratorConfigs();
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
   for (std::string const& conf : configs) {
     this->FollowCommandDepends(cc, conf, emitted);
   }
@@ -6843,7 +6844,7 @@ bool cmGeneratorTarget::GetConfigCommonSourceFiles(
   std::vector<cmSourceFile*>& files) const
 {
   std::vector<std::string> const& configs =
-    this->Makefile->GetGeneratorConfigs();
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 
   auto it = configs.begin();
   const std::string& firstConfig = *it;
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 6001999..a0cee0e 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -313,19 +313,16 @@ bool cmGlobalGenerator::CheckTargetsForMissingSources() const
         }
       }
 
-      std::vector<std::string> configs;
-      target->Makefile->GetConfigurations(configs);
+      std::vector<std::string> configs =
+        target->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
       std::vector<cmSourceFile*> srcs;
-      if (configs.empty()) {
-        target->GetSourceFiles(srcs, "");
-      } else {
-        for (std::string const& config : configs) {
-          target->GetSourceFiles(srcs, config);
-          if (!srcs.empty()) {
-            break;
-          }
+      for (std::string const& config : configs) {
+        target->GetSourceFiles(srcs, config);
+        if (!srcs.empty()) {
+          break;
         }
       }
+
       if (srcs.empty()) {
         std::ostringstream e;
         e << "No SOURCES given to target: " << target->GetName();
@@ -349,7 +346,8 @@ bool cmGlobalGenerator::CheckTargetsForType() const
       if (target->GetType() == cmStateEnums::EXECUTABLE &&
           target->GetPropertyAsBool("WIN32_EXECUTABLE")) {
         std::vector<std::string> const& configs =
-          target->Makefile->GetGeneratorConfigs();
+          target->Makefile->GetGeneratorConfigs(
+            cmMakefile::IncludeEmptyConfig);
         for (std::string const& config : configs) {
           if (target->GetLinkerLanguage(config) == "Swift") {
             this->GetCMakeInstance()->IssueMessage(
@@ -1701,8 +1699,8 @@ void cmGlobalGenerator::FinalizeTargetCompileInfo()
       cmPolicies::PolicyStatus polSt =
         mf->GetPolicyStatus(cmPolicies::CMP0043);
       if (polSt == cmPolicies::WARN || polSt == cmPolicies::OLD) {
-        std::vector<std::string> configs;
-        mf->GetConfigurations(configs);
+        std::vector<std::string> configs =
+          mf->GetGeneratorConfigs(cmMakefile::ExcludeEmptyConfig);
 
         for (std::string const& c : configs) {
           std::string defPropName =
@@ -3127,7 +3125,8 @@ void cmGlobalGenerator::WriteSummary(cmGeneratorTarget* target)
     fout << "# Source files and their labels\n";
     std::vector<cmSourceFile*> sources;
     std::vector<std::string> const& configs =
-      target->Target->GetMakefile()->GetGeneratorConfigs();
+      target->Target->GetMakefile()->GetGeneratorConfigs(
+        cmMakefile::IncludeEmptyConfig);
     for (std::string const& c : configs) {
       target->GetSourceFiles(sources, c);
     }
@@ -3226,8 +3225,9 @@ bool cmGlobalGenerator::GenerateCPackPropertiesFile()
   const auto& lg = this->LocalGenerators[0];
   cmMakefile* mf = lg->GetMakefile();
 
-  std::vector<std::string> configs;
-  std::string config = mf->GetConfigurations(configs, false);
+  std::vector<std::string> configs =
+    mf->GetGeneratorConfigs(cmMakefile::OnlyMultiConfig);
+  std::string config = mf->GetDefaultConfiguration();
 
   std::string path = cmStrCat(this->CMakeInstance->GetHomeOutputDirectory(),
                               "/CPackProperties.cmake");
diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index 843b0f4..48eb405 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -5,9 +5,9 @@
 #include <algorithm>
 #include <cctype>
 #include <cstdio>
-#include <iterator>
 #include <sstream>
 
+#include <cm/iterator>
 #include <cm/memory>
 #include <cmext/algorithm>
 #include <cmext/memory>
@@ -518,7 +518,8 @@ void cmGlobalNinjaGenerator::Generate()
 
   if (cmSystemTools::GetErrorOccuredFlag()) {
     this->RulesFileStream->setstate(std::ios::failbit);
-    for (auto const& config : this->Makefiles[0]->GetGeneratorConfigs()) {
+    for (auto const& config : this->Makefiles[0]->GetGeneratorConfigs(
+           cmMakefile::IncludeEmptyConfig)) {
       this->GetImplFileStream(config)->setstate(std::ios::failbit);
       this->GetConfigFileStream(config)->setstate(std::ios::failbit);
     }
@@ -1207,7 +1208,8 @@ void cmGlobalNinjaGenerator::AddTargetAlias(const std::string& alias,
     this->TargetAliases[output].GeneratorTarget = nullptr;
     this->DefaultTargetAliases[output].GeneratorTarget = nullptr;
     for (const std::string& config2 :
-         this->Makefiles.front()->GetGeneratorConfigs()) {
+         this->Makefiles.front()->GetGeneratorConfigs(
+           cmMakefile::IncludeEmptyConfig)) {
       this->Configs[config2].TargetAliases[output].GeneratorTarget = nullptr;
     }
   }
@@ -1280,7 +1282,8 @@ void cmGlobalNinjaGenerator::WriteTargetAliases(std::ostream& os)
   }
 
   if (this->IsMultiConfig()) {
-    for (auto const& config : this->Makefiles.front()->GetGeneratorConfigs()) {
+    for (auto const& config : this->Makefiles.front()->GetGeneratorConfigs(
+           cmMakefile::IncludeEmptyConfig)) {
       for (auto const& ta : this->Configs[config].TargetAliases) {
         // Don't write ambiguous aliases.
         if (!ta.second.GeneratorTarget) {
@@ -1339,11 +1342,9 @@ void cmGlobalNinjaGenerator::WriteFolderTargets(std::ostream& os)
     cmGlobalNinjaGenerator::WriteDivider(os);
     std::string const& currentBinaryDir = it.first;
     DirectoryTarget const& dt = it.second;
-    std::vector<std::string> configs;
-    dt.LG->GetMakefile()->GetConfigurations(configs, true);
-    if (configs.empty()) {
-      configs.emplace_back();
-    }
+    std::vector<std::string> configs =
+      dt.LG->GetMakefile()->GetGeneratorConfigs(
+        cmMakefile::IncludeEmptyConfig);
 
     // Setup target
     cmNinjaDeps configDeps;
@@ -1538,7 +1539,8 @@ void cmGlobalNinjaGenerator::WriteBuiltinTargets(std::ostream& os)
   this->WriteTargetClean(os);
   this->WriteTargetHelp(os);
 
-  for (auto const& config : this->Makefiles[0]->GetGeneratorConfigs()) {
+  for (auto const& config : this->Makefiles[0]->GetGeneratorConfigs(
+         cmMakefile::IncludeEmptyConfig)) {
     this->WriteTargetDefault(*this->GetConfigFileStream(config));
   }
 
@@ -1712,11 +1714,8 @@ bool cmGlobalNinjaGenerator::WriteTargetCleanAdditional(std::ostream& os)
   std::string cleanScriptRel = "CMakeFiles/clean_additional.cmake";
   std::string cleanScriptAbs =
     cmStrCat(lgr->GetBinaryDirectory(), '/', cleanScriptRel);
-  std::vector<std::string> configs;
-  this->Makefiles[0]->GetConfigurations(configs, true);
-  if (configs.empty()) {
-    configs.emplace_back();
-  }
+  std::vector<std::string> configs =
+    this->Makefiles[0]->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 
   // Check if there are additional files to clean
   bool empty = true;
@@ -1810,7 +1809,8 @@ void cmGlobalNinjaGenerator::WriteTargetClean(std::ostream& os)
     WriteRule(*this->RulesFileStream, rule);
   }
 
-  auto const configs = this->Makefiles.front()->GetGeneratorConfigs();
+  auto const configs = this->Makefiles.front()->GetGeneratorConfigs(
+    cmMakefile::IncludeEmptyConfig);
 
   // Write build
   {
@@ -2489,7 +2489,8 @@ bool cmGlobalNinjaMultiGenerator::OpenBuildFileStreams()
     << "# This file contains build statements common to all "
        "configurations.\n\n";
 
-  for (auto const& config : this->Makefiles[0]->GetGeneratorConfigs()) {
+  for (auto const& config : this->Makefiles[0]->GetGeneratorConfigs(
+         cmMakefile::IncludeEmptyConfig)) {
     // Open impl file.
     if (!this->OpenFileStream(this->ImplFileStreams[config],
                               GetNinjaImplFilename(config))) {
@@ -2529,7 +2530,8 @@ void cmGlobalNinjaMultiGenerator::CloseBuildFileStreams()
     this->DefaultFileStream.reset();
   } // No error if it wasn't open
 
-  for (auto const& config : this->Makefiles[0]->GetGeneratorConfigs()) {
+  for (auto const& config : this->Makefiles[0]->GetGeneratorConfigs(
+         cmMakefile::IncludeEmptyConfig)) {
     if (this->ImplFileStreams[config]) {
       this->ImplFileStreams[config].reset();
     } else {
@@ -2571,7 +2573,8 @@ std::string cmGlobalNinjaMultiGenerator::GetNinjaConfigFilename(
 void cmGlobalNinjaMultiGenerator::AddRebuildManifestOutputs(
   cmNinjaDeps& outputs) const
 {
-  for (auto const& config : this->Makefiles.front()->GetGeneratorConfigs()) {
+  for (auto const& config : this->Makefiles.front()->GetGeneratorConfigs(
+         cmMakefile::IncludeEmptyConfig)) {
     outputs.push_back(this->NinjaOutputPath(GetNinjaImplFilename(config)));
     outputs.push_back(this->NinjaOutputPath(GetNinjaConfigFilename(config)));
   }
@@ -2583,11 +2586,9 @@ void cmGlobalNinjaMultiGenerator::AddRebuildManifestOutputs(
 void cmGlobalNinjaMultiGenerator::GetQtAutoGenConfigs(
   std::vector<std::string>& configs) const
 {
-  auto const oldSize = configs.size();
-  this->Makefiles.front()->GetConfigurations(configs);
-  if (configs.size() == oldSize) {
-    configs.emplace_back();
-  }
+  auto allConfigs =
+    this->Makefiles[0]->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
+  configs.insert(configs.end(), cm::cbegin(allConfigs), cm::cend(allConfigs));
 }
 
 bool cmGlobalNinjaMultiGenerator::InspectConfigTypeVariables()
diff --git a/Source/cmGlobalVisualStudio71Generator.cxx b/Source/cmGlobalVisualStudio71Generator.cxx
index 7ada325..0083c40 100644
--- a/Source/cmGlobalVisualStudio71Generator.cxx
+++ b/Source/cmGlobalVisualStudio71Generator.cxx
@@ -19,8 +19,8 @@ void cmGlobalVisualStudio71Generator::WriteSLNFile(
   std::ostream& fout, cmLocalGenerator* root,
   std::vector<cmLocalGenerator*>& generators)
 {
-  std::vector<std::string> configs;
-  root->GetMakefile()->GetConfigurations(configs);
+  std::vector<std::string> configs =
+    root->GetMakefile()->GetGeneratorConfigs(cmMakefile::ExcludeEmptyConfig);
 
   // Write out the header for a SLN file
   this->WriteSLNHeader(fout);
diff --git a/Source/cmGlobalVisualStudio7Generator.cxx b/Source/cmGlobalVisualStudio7Generator.cxx
index 428c748..9f798e6 100644
--- a/Source/cmGlobalVisualStudio7Generator.cxx
+++ b/Source/cmGlobalVisualStudio7Generator.cxx
@@ -568,8 +568,9 @@ void cmGlobalVisualStudio7Generator::WriteSLNFooter(std::ostream& fout)
 std::string cmGlobalVisualStudio7Generator::WriteUtilityDepend(
   cmGeneratorTarget const* target)
 {
-  std::vector<std::string> configs;
-  target->Target->GetMakefile()->GetConfigurations(configs);
+  std::vector<std::string> configs =
+    target->Target->GetMakefile()->GetGeneratorConfigs(
+      cmMakefile::ExcludeEmptyConfig);
   std::string pname = cmStrCat(target->GetName(), "_UTILITY");
   std::string fname =
     cmStrCat(target->GetLocalGenerator()->GetCurrentBinaryDirectory(), '/',
diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index bb422eb..67e795b 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -1077,11 +1077,8 @@ void cmGlobalXCodeGenerator::SetCurrentLocalGenerator(cmLocalGenerator* gen)
   this->CurrentMakefile = gen->GetMakefile();
 
   // Select the current set of configuration types.
-  this->CurrentConfigurationTypes.clear();
-  this->CurrentMakefile->GetConfigurations(this->CurrentConfigurationTypes);
-  if (this->CurrentConfigurationTypes.empty()) {
-    this->CurrentConfigurationTypes.emplace_back();
-  }
+  this->CurrentConfigurationTypes =
+    this->CurrentMakefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 }
 
 struct cmSourceFilePathCompare
diff --git a/Source/cmJsonObjects.cxx b/Source/cmJsonObjects.cxx
index 9f17f15..3a2e3be 100644
--- a/Source/cmJsonObjects.cxx
+++ b/Source/cmJsonObjects.cxx
@@ -51,11 +51,7 @@ std::vector<std::string> getConfigurations(const cmake* cm)
     return configurations;
   }
 
-  makefiles[0]->GetConfigurations(configurations);
-  if (configurations.empty()) {
-    configurations.emplace_back();
-  }
-  return configurations;
+  return makefiles[0]->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 }
 
 bool hasString(const Json::Value& v, const std::string& s)
diff --git a/Source/cmLinkItemGraphVisitor.cxx b/Source/cmLinkItemGraphVisitor.cxx
index b13def8..dfdd3ff 100644
--- a/Source/cmLinkItemGraphVisitor.cxx
+++ b/Source/cmLinkItemGraphVisitor.cxx
@@ -28,7 +28,8 @@ void cmLinkItemGraphVisitor::VisitLinks(cmLinkItem const& item,
     return;
   }
 
-  for (auto const& config : item.Target->Makefile->GetGeneratorConfigs()) {
+  for (auto const& config : item.Target->Makefile->GetGeneratorConfigs(
+         cmMakefile::IncludeEmptyConfig)) {
     this->VisitLinks(item, rootItem, config);
   }
 }
diff --git a/Source/cmLocalCommonGenerator.cxx b/Source/cmLocalCommonGenerator.cxx
index 278ec8b..44db842 100644
--- a/Source/cmLocalCommonGenerator.cxx
+++ b/Source/cmLocalCommonGenerator.cxx
@@ -17,10 +17,8 @@ cmLocalCommonGenerator::cmLocalCommonGenerator(cmGlobalGenerator* gg,
   : cmLocalGenerator(gg, mf)
   , WorkingDirectory(std::move(wd))
 {
-  this->Makefile->GetConfigurations(this->ConfigNames);
-  if (this->ConfigNames.empty()) {
-    this->ConfigNames.emplace_back();
-  }
+  this->ConfigNames =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 }
 
 cmLocalCommonGenerator::~cmLocalCommonGenerator() = default;
diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 42a5780..1fa7c7b 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -297,9 +297,9 @@ void cmLocalGenerator::GenerateTestFiles()
   }
 
   // Compute the set of configurations.
-  std::vector<std::string> configurationTypes;
-  const std::string& config =
-    this->Makefile->GetConfigurations(configurationTypes, false);
+  std::vector<std::string> configurationTypes =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::OnlyMultiConfig);
+  std::string config = this->Makefile->GetDefaultConfiguration();
 
   std::string file =
     cmStrCat(this->StateSnapshot.GetDirectory().GetCurrentBinary(),
@@ -379,7 +379,7 @@ void cmLocalGenerator::GenerateTestFiles()
 void cmLocalGenerator::CreateEvaluationFileOutputs()
 {
   std::vector<std::string> const& configs =
-    this->Makefile->GetGeneratorConfigs();
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
   for (std::string const& c : configs) {
     this->CreateEvaluationFileOutputs(c);
   }
@@ -462,9 +462,9 @@ void cmLocalGenerator::GenerateInstallRules()
   }
 
   // Compute the set of configurations.
-  std::vector<std::string> configurationTypes;
-  const std::string& config =
-    this->Makefile->GetConfigurations(configurationTypes, false);
+  std::vector<std::string> configurationTypes =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::OnlyMultiConfig);
+  std::string config = this->Makefile->GetDefaultConfiguration();
 
   // Choose a default install configuration.
   std::string default_config = config;
@@ -753,11 +753,8 @@ cmGeneratorTarget* cmLocalGenerator::FindLocalNonAliasGeneratorTarget(
 void cmLocalGenerator::ComputeTargetManifest()
 {
   // Collect the set of configuration types.
-  std::vector<std::string> configNames;
-  this->Makefile->GetConfigurations(configNames);
-  if (configNames.empty()) {
-    configNames.emplace_back();
-  }
+  std::vector<std::string> configNames =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 
   // Add our targets to the manifest for each configuration.
   const auto& targets = this->GetGeneratorTargets();
@@ -774,11 +771,8 @@ void cmLocalGenerator::ComputeTargetManifest()
 bool cmLocalGenerator::ComputeTargetCompileFeatures()
 {
   // Collect the set of configuration types.
-  std::vector<std::string> configNames;
-  this->Makefile->GetConfigurations(configNames);
-  if (configNames.empty()) {
-    configNames.emplace_back();
-  }
+  std::vector<std::string> configNames =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 
   using LanguagePair = std::pair<std::string, std::string>;
   std::vector<LanguagePair> pairedLanguages{ { "OBJC", "C" },
@@ -2551,11 +2545,8 @@ void cmLocalGenerator::AppendFlagEscape(std::string& flags,
 
 void cmLocalGenerator::AddPchDependencies(cmGeneratorTarget* target)
 {
-  std::vector<std::string> configsList;
-  std::string configDefault = this->Makefile->GetConfigurations(configsList);
-  if (configsList.empty()) {
-    configsList.push_back(configDefault);
-  }
+  std::vector<std::string> configsList =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 
   for (std::string const& config : configsList) {
     // FIXME: Refactor collection of sources to not evaluate object
diff --git a/Source/cmLocalVisualStudio7Generator.cxx b/Source/cmLocalVisualStudio7Generator.cxx
index 5d50e2d..ad61ad3 100644
--- a/Source/cmLocalVisualStudio7Generator.cxx
+++ b/Source/cmLocalVisualStudio7Generator.cxx
@@ -1331,8 +1331,8 @@ void cmLocalVisualStudio7Generator::WriteVCProjFile(std::ostream& fout,
                                                     const std::string& libName,
                                                     cmGeneratorTarget* target)
 {
-  std::vector<std::string> configs;
-  this->Makefile->GetConfigurations(configs);
+  std::vector<std::string> configs =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::ExcludeEmptyConfig);
 
   // We may be modifying the source groups temporarily, so make a copy.
   std::vector<cmSourceGroup> sourceGroups = this->Makefile->GetSourceGroups();
@@ -1580,8 +1580,9 @@ cmLocalVisualStudio7GeneratorFCInfo::cmLocalVisualStudio7GeneratorFCInfo(
 std::string cmLocalVisualStudio7Generator::ComputeLongestObjectDirectory(
   cmGeneratorTarget const* target) const
 {
-  std::vector<std::string> configs;
-  target->Target->GetMakefile()->GetConfigurations(configs);
+  std::vector<std::string> configs =
+    target->Target->GetMakefile()->GetGeneratorConfigs(
+      cmMakefile::ExcludeEmptyConfig);
 
   // Compute the maximum length configuration name.
   std::string config_max;
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 70861ce..e88f8ea 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -1436,8 +1436,8 @@ void cmMakefile::InitializeFromParent(cmMakefile* parent)
   if (polSt == cmPolicies::WARN || polSt == cmPolicies::OLD) {
     cmProp p = parent->GetProperty("COMPILE_DEFINITIONS");
     this->SetProperty("COMPILE_DEFINITIONS", p ? p->c_str() : nullptr);
-    std::vector<std::string> configs;
-    this->GetConfigurations(configs);
+    std::vector<std::string> configs =
+      this->GetGeneratorConfigs(cmMakefile::ExcludeEmptyConfig);
     for (std::string const& config : configs) {
       std::string defPropName =
         cmStrCat("COMPILE_DEFINITIONS_", cmSystemTools::UpperCase(config));
@@ -3251,25 +3251,28 @@ void cmMakefile::RemoveVariablesInString(std::string& source,
   }
 }
 
-std::string cmMakefile::GetConfigurations(std::vector<std::string>& configs,
-                                          bool singleConfig) const
+std::string cmMakefile::GetDefaultConfiguration() const
 {
   if (this->GetGlobalGenerator()->IsMultiConfig()) {
-    this->GetDefExpandList("CMAKE_CONFIGURATION_TYPES", configs);
-    return "";
-  }
-  const std::string& buildType = this->GetSafeDefinition("CMAKE_BUILD_TYPE");
-  if (singleConfig && !buildType.empty()) {
-    configs.push_back(buildType);
+    return std::string{};
   }
-  return buildType;
+  return this->GetSafeDefinition("CMAKE_BUILD_TYPE");
 }
 
-std::vector<std::string> cmMakefile::GetGeneratorConfigs() const
+std::vector<std::string> cmMakefile::GetGeneratorConfigs(
+  GeneratorConfigQuery mode) const
 {
   std::vector<std::string> configs;
-  GetConfigurations(configs);
-  if (configs.empty()) {
+  if (this->GetGlobalGenerator()->IsMultiConfig() ||
+      mode == cmMakefile::OnlyMultiConfig) {
+    this->GetDefExpandList("CMAKE_CONFIGURATION_TYPES", configs);
+  } else {
+    const std::string& buildType = this->GetSafeDefinition("CMAKE_BUILD_TYPE");
+    if (!buildType.empty()) {
+      configs.emplace_back(buildType);
+    }
+  }
+  if (mode == cmMakefile::IncludeEmptyConfig && configs.empty()) {
     configs.emplace_back();
   }
   return configs;
diff --git a/Source/cmMakefile.h b/Source/cmMakefile.h
index 323ab5a..be50413 100644
--- a/Source/cmMakefile.h
+++ b/Source/cmMakefile.h
@@ -343,12 +343,19 @@ public:
    */
   void SetProjectName(std::string const& name);
 
-  /** Get the configurations to be generated.  */
-  std::string GetConfigurations(std::vector<std::string>& configs,
-                                bool single = true) const;
+  /* Get the default configuration */
+  std::string GetDefaultConfiguration() const;
+
+  enum GeneratorConfigQuery
+  {
+    IncludeEmptyConfig, // Include "" aka noconfig
+    ExcludeEmptyConfig, // Exclude "" aka noconfig
+    OnlyMultiConfig,
+  };
 
   /** Get the configurations for dependency checking.  */
-  std::vector<std::string> GetGeneratorConfigs() const;
+  std::vector<std::string> GetGeneratorConfigs(
+    GeneratorConfigQuery mode) const;
 
   /**
    * Set the name of the library.
diff --git a/Source/cmNinjaTargetGenerator.cxx b/Source/cmNinjaTargetGenerator.cxx
index 0c7591a..53a0cb7 100644
--- a/Source/cmNinjaTargetGenerator.cxx
+++ b/Source/cmNinjaTargetGenerator.cxx
@@ -65,7 +65,8 @@ cmNinjaTargetGenerator::cmNinjaTargetGenerator(cmGeneratorTarget* target)
   , LocalGenerator(
       static_cast<cmLocalNinjaGenerator*>(target->GetLocalGenerator()))
 {
-  for (auto const& fileConfig : target->Makefile->GetGeneratorConfigs()) {
+  for (auto const& fileConfig :
+       target->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig)) {
     this->Configs[fileConfig].MacOSXContentGenerator =
       cm::make_unique<MacOSXContentGeneratorType>(this, fileConfig);
   }
diff --git a/Source/cmQtAutoGenInitializer.cxx b/Source/cmQtAutoGenInitializer.cxx
index e733a3e..7e0bf96 100644
--- a/Source/cmQtAutoGenInitializer.cxx
+++ b/Source/cmQtAutoGenInitializer.cxx
@@ -315,10 +315,9 @@ bool cmQtAutoGenInitializer::InitCustomTargets()
 {
   // Configurations
   this->MultiConfig = this->GlobalGen->IsMultiConfig();
-  this->ConfigDefault = this->Makefile->GetConfigurations(this->ConfigsList);
-  if (this->ConfigsList.empty()) {
-    this->ConfigsList.push_back(this->ConfigDefault);
-  }
+  this->ConfigDefault = this->Makefile->GetDefaultConfiguration();
+  this->ConfigsList =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
 
   // Verbosity
   {
diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index 9f9b6f9..72c7600 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -419,8 +419,8 @@ cmTarget::cmTarget(std::string const& name, cmStateEnums::TargetType type,
       "INTERPROCEDURAL_OPTIMIZATION_"
     };
     // Collect the set of configuration types.
-    std::vector<std::string> configNames;
-    mf->GetConfigurations(configNames);
+    std::vector<std::string> configNames =
+      mf->GetGeneratorConfigs(cmMakefile::ExcludeEmptyConfig);
     for (std::string const& configName : configNames) {
       std::string configUpper = cmSystemTools::UpperCase(configName);
       for (auto const& prop : configProps) {
diff --git a/Source/cmVisualStudio10TargetGenerator.cxx b/Source/cmVisualStudio10TargetGenerator.cxx
index 31754f4..5f6b41d 100644
--- a/Source/cmVisualStudio10TargetGenerator.cxx
+++ b/Source/cmVisualStudio10TargetGenerator.cxx
@@ -232,7 +232,8 @@ cmVisualStudio10TargetGenerator::cmVisualStudio10TargetGenerator(
   , LocalGenerator(
       (cmLocalVisualStudio10Generator*)target->GetLocalGenerator())
 {
-  this->Makefile->GetConfigurations(this->Configurations);
+  this->Configurations =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::ExcludeEmptyConfig);
   this->NsightTegra = gg->IsNsightTegra();
   this->Android = gg->TargetsAndroid();
   for (int i = 0; i < 4; ++i) {