cmTarget: Move initialization to implementation class

Move a bunch of low-level member initialization from `cmTarget` to
`cmTargetInternals`, and in particular, to inline default member
initializers where possible. This gives us the advantages of the latter
with no overhead, as the compiler will elide generating DMI code for
those members that are unconditionally initialized in the ctor. (We were
getting the same optimization already for members that were initialized
twice in the `cmTarget` ctor, but without the benefits of DMIs.)

Mostly, this means we have assurance, via the DMIs, that POD members are
initialized without having to verify whether there is explicit code to
do so, while retaining not paying for double initialization.

Also, because it just gets moved into place, change `cmTarget`'s ctor to
take the target name by value.

Source/cmTarget.cxx

@@ -604,21 +604,21 @@ public:
   cmTarget::Origin Origin = cmTarget::Origin::Unknown;
   cmMakefile* Makefile;
   cmPolicies::PolicyMap PolicyMap;
-  cmTarget const* TemplateTarget;
+  cmTarget const* TemplateTarget = nullptr;
   std::string Name;
   std::string InstallPath;
   std::string RuntimeInstallPath;
   cmPropertyMap Properties;
-  bool IsGeneratorProvided;
-  bool HaveInstallRule;
-  bool IsDLLPlatform;
-  bool IsAIX;
-  bool IsApple;
-  bool IsAndroid;
-  bool BuildInterfaceIncludesAppended;
-  bool PerConfig;
-  bool IsSymbolic;
-  bool IsForTryCompile{ false };
+  bool IsGeneratorProvided = false;
+  bool HaveInstallRule = false;
+  bool IsDLLPlatform = false;
+  bool IsAIX = false;
+  bool IsApple = false;
+  bool IsAndroid = false;
+  bool BuildInterfaceIncludesAppended = false;
+  bool PerConfig = false;
+  bool IsSymbolic = false;
+  bool IsForTryCompile = false;
   cmTarget::Visibility TargetVisibility;
   std::set<BT<std::pair<std::string, bool>>> Utilities;
   std::set<std::string> CodegenDependencies;
@@ -657,7 +657,9 @@ public:
 
   std::unordered_map<cm::string_view, FileSetType> FileSetTypes;
 
-  cmTargetInternals();
+  cmTargetInternals(std::string name, cmStateEnums::TargetType type,
+                    cmTarget::Visibility visibility, cmMakefile* mf,
+                    cmTarget::PerConfig perConfig);
 
   bool IsImported() const;
 
@@ -687,8 +689,17 @@ public:
   }
 };
 
-cmTargetInternals::cmTargetInternals()
-  : IncludeDirectories("INCLUDE_DIRECTORIES"_s)
+cmTargetInternals::cmTargetInternals(std::string name,
+                                     cmStateEnums::TargetType type,
+                                     cmTarget::Visibility visibility,
+                                     cmMakefile* mf,
+                                     cmTarget::PerConfig perConfig)
+  : TargetType(type)
+  , Makefile(mf)
+  , Name(std::move(name))
+  , PerConfig(perConfig == cmTarget::PerConfig::Yes)
+  , TargetVisibility(visibility)
+  , IncludeDirectories("INCLUDE_DIRECTORIES"_s)
   , CompileOptions("COMPILE_OPTIONS"_s)
   , CompileFeatures("COMPILE_FEATURES"_s)
   , CompileDefinitions("COMPILE_DEFINITIONS"_s)
@@ -729,6 +740,29 @@ cmTargetInternals::cmTargetInternals()
                       FileSetEntries{ "CXX_MODULE_SETS"_s },
                       FileSetEntries{ "INTERFACE_CXX_MODULE_SETS"_s } } } }
 {
+  assert(mf);
+
+  // Check whether this is a DLL platform.
+  this->IsDLLPlatform =
+    !mf->GetSafeDefinition("CMAKE_IMPORT_LIBRARY_SUFFIX").empty();
+
+  // Check whether we are targeting AIX.
+  {
+    std::string const& systemName = mf->GetSafeDefinition("CMAKE_SYSTEM_NAME");
+    this->IsAIX = (systemName == "AIX" || systemName == "OS400");
+  }
+
+  // Check whether we are targeting Apple.
+  this->IsApple = mf->IsOn("APPLE");
+
+  // Check whether we are targeting an Android platform.
+  this->IsAndroid = (mf->GetSafeDefinition("CMAKE_SYSTEM_NAME") == "Android");
+
+  // Save the backtrace of target construction.
+  this->Backtrace = mf->GetBacktrace();
+  if (this->IsImported()) {
+    this->FindPackageStack = mf->GetFindPackageStack();
+  }
 }
 
 template <typename ValueType>
@@ -889,51 +923,11 @@ std::pair<bool, cmValue> UsageRequirementProperty::Read(
   return { did_read, value };
 }
 
-cmTarget::cmTarget(std::string const& name, cmStateEnums::TargetType type,
+cmTarget::cmTarget(std::string name, cmStateEnums::TargetType type,
                    Visibility vis, cmMakefile* mf, PerConfig perConfig)
-  : impl(cm::make_unique<cmTargetInternals>())
+  : impl(cm::make_unique<cmTargetInternals>(std::move(name), type, vis, mf,
+                                            perConfig))
 {
-  assert(mf);
-  this->impl->TargetType = type;
-  this->impl->Makefile = mf;
-  this->impl->Name = name;
-  this->impl->TemplateTarget = nullptr;
-  this->impl->IsGeneratorProvided = false;
-  this->impl->HaveInstallRule = false;
-  this->impl->IsDLLPlatform = false;
-  this->impl->IsAIX = false;
-  this->impl->IsApple = false;
-  this->impl->IsAndroid = false;
-  this->impl->IsSymbolic = false;
-  this->impl->TargetVisibility = vis;
-  this->impl->BuildInterfaceIncludesAppended = false;
-  this->impl->PerConfig = (perConfig == PerConfig::Yes);
-
-  // Check whether this is a DLL platform.
-  this->impl->IsDLLPlatform =
-    !this->impl->Makefile->GetSafeDefinition("CMAKE_IMPORT_LIBRARY_SUFFIX")
-       .empty();
-
-  // Check whether we are targeting AIX.
-  {
-    std::string const& systemName =
-      this->impl->Makefile->GetSafeDefinition("CMAKE_SYSTEM_NAME");
-    this->impl->IsAIX = (systemName == "AIX" || systemName == "OS400");
-  }
-
-  // Check whether we are targeting Apple.
-  this->impl->IsApple = this->impl->Makefile->IsOn("APPLE");
-
-  // Check whether we are targeting an Android platform.
-  this->impl->IsAndroid = (this->impl->Makefile->GetSafeDefinition(
-                             "CMAKE_SYSTEM_NAME") == "Android");
-
-  // Save the backtrace of target construction.
-  this->impl->Backtrace = this->impl->Makefile->GetBacktrace();
-  if (this->impl->IsImported()) {
-    this->impl->FindPackageStack = this->impl->Makefile->GetFindPackageStack();
-  }
-
   if (this->IsNormal()) {
     // Initialize the INCLUDE_DIRECTORIES property based on the current value
     // of the same directory property:

Source/cmTarget.h

@@ -69,8 +69,8 @@ public:
     No
   };
 
-  cmTarget(std::string const& name, cmStateEnums::TargetType type,
-           Visibility vis, cmMakefile* mf, PerConfig perConfig);
+  cmTarget(std::string name, cmStateEnums::TargetType type, Visibility vis,
+           cmMakefile* mf, PerConfig perConfig);
 
   cmTarget(cmTarget const&) = delete;
   cmTarget(cmTarget&&) noexcept;