Ninja: In cmNinjaTargetGenerator use std::unique_ptr to manage new instances

Source/cmLocalNinjaGenerator.cxx

@@ -83,14 +83,13 @@ void cmLocalNinjaGenerator::Generate()
     if (target->GetType() == cmStateEnums::INTERFACE_LIBRARY) {
       continue;
     }
-    cmNinjaTargetGenerator* tg = cmNinjaTargetGenerator::New(target);
+    auto tg = cmNinjaTargetGenerator::New(target);
     if (tg) {
       tg->Generate();
       // Add the target to "all" if required.
       if (!this->GetGlobalNinjaGenerator()->IsExcluded(target)) {
         this->GetGlobalNinjaGenerator()->AddDependencyToAll(target);
       }
-      delete tg;
     }
   }
 

Source/cmNinjaTargetGenerator.cxx

@@ -33,7 +33,8 @@
 #include "cmSystemTools.h"
 #include "cmake.h"
 
-cmNinjaTargetGenerator* cmNinjaTargetGenerator::New(cmGeneratorTarget* target)
+std::unique_ptr<cmNinjaTargetGenerator> cmNinjaTargetGenerator::New(
+  cmGeneratorTarget* target)
 {
   switch (target->GetType()) {
     case cmStateEnums::EXECUTABLE:
@@ -41,14 +42,14 @@ cmNinjaTargetGenerator* cmNinjaTargetGenerator::New(cmGeneratorTarget* target)
     case cmStateEnums::STATIC_LIBRARY:
     case cmStateEnums::MODULE_LIBRARY:
     case cmStateEnums::OBJECT_LIBRARY:
-      return new cmNinjaNormalTargetGenerator(target);
+      return cm::make_unique<cmNinjaNormalTargetGenerator>(target);
 
     case cmStateEnums::UTILITY:
     case cmStateEnums::GLOBAL_TARGET:
-      return new cmNinjaUtilityTargetGenerator(target);
+      return cm::make_unique<cmNinjaUtilityTargetGenerator>(target);
 
     default:
-      return nullptr;
+      return std::unique_ptr<cmNinjaTargetGenerator>();
   }
 }
 

Source/cmNinjaTargetGenerator.h

@@ -11,6 +11,7 @@
 #include "cmOSXBundleGenerator.h"
 
 #include <map>
+#include <memory> // IWYU pragma: keep
 #include <set>
 #include <string>
 #include <vector>
@@ -26,7 +27,8 @@ class cmNinjaTargetGenerator : public cmCommonTargetGenerator
 {
 public:
   /// Create a cmNinjaTargetGenerator according to the @a target's type.
-  static cmNinjaTargetGenerator* New(cmGeneratorTarget* target);
+  static std::unique_ptr<cmNinjaTargetGenerator> New(
+    cmGeneratorTarget* target);
 
   /// Build a NinjaTargetGenerator.
   cmNinjaTargetGenerator(cmGeneratorTarget* target);