Autogen: Evaluate compiler features for the same exectuable only once

To speed up the `AUTOGEN` configuration process, evaluate the compiler
features only once.  The feature evaluation result is stored in the new class
`cmQtAutoGen::CompilerFeatures`, and the instance is shared by using
`std::shared_ptr`.

1 files changed, 7 insertions, 4 deletions

diff --git a/Source/cmQtAutoGenGlobalInitializer.h b/Source/cmQtAutoGenGlobalInitializer.h
index 77429b7cbc..d56153ab7a 100644
--- a/Source/cmQtAutoGenGlobalInitializer.h
+++ b/Source/cmQtAutoGenGlobalInitializer.h
@@ -5,6 +5,8 @@
 
 #include "cmConfigure.h" // IWYU pragma: keep
 
+#include "cmQtAutoGen.h"
+
 #include <map>
 #include <memory> // IWYU pragma: keep
 #include <string>
@@ -68,15 +70,16 @@ private:
   void AddToGlobalAutoRcc(cmLocalGenerator* localGen,
                           std::string const& targetName);
 
-  bool GetExecutableTestOutput(std::string const& generator,
-                               std::string const& executable,
-                               std::string& error, std::string* output);
+  cmQtAutoGen::CompilerFeaturesHandle GetCompilerFeatures(
+    std::string const& generator, std::string const& executable,
+    std::string& error);
 
 private:
   std::vector<std::unique_ptr<cmQtAutoGenInitializer>> Initializers_;
   std::map<cmLocalGenerator*, std::string> GlobalAutoGenTargets_;
   std::map<cmLocalGenerator*, std::string> GlobalAutoRccTargets_;
-  std::unordered_map<std::string, std::string> ExecutableTestOutputs_;
+  std::unordered_map<std::string, cmQtAutoGen::CompilerFeaturesHandle>
+    CompilerFeatures_;
   Keywords const Keywords_;
 };