cmState: Support BuiltinCommands as free functions

Source/cmCommands.cxx

@@ -162,7 +162,7 @@ void GetScriptingCommands(cmState* state)
   state->AddBuiltinCommand("option", cm::make_unique<cmOptionCommand>());
   state->AddBuiltinCommand("cmake_parse_arguments",
                            cm::make_unique<cmParseArgumentsCommand>());
-  state->AddBuiltinCommand("return", cm::make_unique<cmReturnCommand>());
+  state->AddBuiltinCommand("return", cmReturnCommand);
   state->AddBuiltinCommand("separate_arguments",
                            cm::make_unique<cmSeparateArgumentsCommand>());
   state->AddBuiltinCommand("set", cm::make_unique<cmSetCommand>());
@@ -255,8 +255,7 @@ void GetProjectCommands(cmState* state)
                            cm::make_unique<cmDefinePropertyCommand>());
   state->AddBuiltinCommand("enable_language",
                            cm::make_unique<cmEnableLanguageCommand>());
-  state->AddBuiltinCommand("enable_testing",
-                           cm::make_unique<cmEnableTestingCommand>());
+  state->AddBuiltinCommand("enable_testing", cmEnableTestingCommand);
   state->AddBuiltinCommand("get_source_file_property",
                            cm::make_unique<cmGetSourceFilePropertyCommand>());
   state->AddBuiltinCommand("get_target_property",

Source/cmEnableTestingCommand.cxx

@@ -2,15 +2,12 @@
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #include "cmEnableTestingCommand.h"
 
+#include "cmExecutionStatus.h"
 #include "cmMakefile.h"
 
-class cmExecutionStatus;
-
-// we do this in the final pass so that we now the subdirs have all
-// been defined
-bool cmEnableTestingCommand::InitialPass(std::vector<std::string> const&,
-                                         cmExecutionStatus&)
+bool cmEnableTestingCommand(std::vector<std::string> const&,
+                            cmExecutionStatus& status)
 {
-  this->Makefile->AddDefinition("CMAKE_TESTING_ENABLED", "1");
+  status.GetMakefile().AddDefinition("CMAKE_TESTING_ENABLED", "1");
   return true;
 }

Source/cmEnableTestingCommand.h

@@ -8,13 +8,9 @@
 #include <string>
 #include <vector>
 
-#include "cm_memory.hxx"
-
-#include "cmCommand.h"
-
 class cmExecutionStatus;
 
-/** \class cmEnableTestingCommand
+/**
  * \brief Enable testing for this directory and below.
  *
  * Produce the output testfile. This produces a file in the build directory
@@ -27,23 +23,7 @@ class cmExecutionStatus;
  * Note that CTest expects to find this file in the build directory root;
  * therefore, this command should be in the source directory root too.
  */
-class cmEnableTestingCommand : public cmCommand
-{
-public:
-  /**
-   * This is a virtual constructor for the command.
-   */
-  std::unique_ptr<cmCommand> Clone() override
-  {
-    return cm::make_unique<cmEnableTestingCommand>();
-  }
-
-  /**
-   * This is called when the command is first encountered in
-   * the CMakeLists.txt file.
-   */
-  bool InitialPass(std::vector<std::string> const&,
-                   cmExecutionStatus&) override;
-};
+bool cmEnableTestingCommand(std::vector<std::string> const&,
+                            cmExecutionStatus&);
 
 #endif

Source/cmReturnCommand.cxx

@@ -5,8 +5,8 @@
 #include "cmExecutionStatus.h"
 
 // cmReturnCommand
-bool cmReturnCommand::InitialPass(std::vector<std::string> const&,
-                                  cmExecutionStatus& status)
+bool cmReturnCommand(std::vector<std::string> const&,
+                     cmExecutionStatus& status)
 {
   status.SetReturnInvoked();
   return true;

Source/cmReturnCommand.h

@@ -8,34 +8,10 @@
 #include <string>
 #include <vector>
 
-#include "cm_memory.hxx"
-
-#include "cmCommand.h"
-
 class cmExecutionStatus;
 
-/** \class cmReturnCommand
- * \brief Return from a directory or function
- *
- * cmReturnCommand returns from a directory or function
- */
-class cmReturnCommand : public cmCommand
-{
-public:
-  /**
-   * This is a virtual constructor for the command.
-   */
-  std::unique_ptr<cmCommand> Clone() override
-  {
-    return cm::make_unique<cmReturnCommand>();
-  }
-
-  /**
-   * This is called when the command is first encountered in
-   * the CMakeLists.txt file.
-   */
-  bool InitialPass(std::vector<std::string> const& args,
-                   cmExecutionStatus& status) override;
-};
+/// Return from a directory or function
+bool cmReturnCommand(std::vector<std::string> const& args,
+                     cmExecutionStatus& status);
 
 #endif

Source/cmState.cxx

@@ -432,6 +432,23 @@ void cmState::AddBuiltinCommand(std::string const& name, Command command)
   this->BuiltinCommands.emplace(name, std::move(command));
 }
 
+void cmState::AddBuiltinCommand(std::string const& name,
+                                BuiltinCommand command)
+{
+  this->AddBuiltinCommand(
+    name,
+    [command](const std::vector<cmListFileArgument>& args,
+              cmExecutionStatus& status) -> bool {
+      std::vector<std::string> expandedArguments;
+      if (!status.GetMakefile().ExpandArguments(args, expandedArguments)) {
+        // There was an error expanding arguments.  It was already
+        // reported, so we can skip this command without error.
+        return true;
+      }
+      return command(expandedArguments, status);
+    });
+}
+
 void cmState::AddDisallowedCommand(std::string const& name,
                                    std::unique_ptr<cmCommand> command,
                                    cmPolicies::PolicyID policy,

Source/cmState.h

@@ -145,6 +145,8 @@ public:
 
   using Command = std::function<bool(std::vector<cmListFileArgument> const&,
                                      cmExecutionStatus&)>;
+  using BuiltinCommand = bool (*)(std::vector<std::string> const&,
+                                  cmExecutionStatus&);
 
   // Returns a command from its name, case insensitive, or nullptr
   Command GetCommand(std::string const& name) const;
@@ -154,6 +156,7 @@ public:
   void AddBuiltinCommand(std::string const& name,
                          std::unique_ptr<cmCommand> command);
   void AddBuiltinCommand(std::string const& name, Command command);
+  void AddBuiltinCommand(std::string const& name, BuiltinCommand command);
   void AddDisallowedCommand(std::string const& name,
                             std::unique_ptr<cmCommand> command,
                             cmPolicies::PolicyID policy, const char* message);