cmGlobalGenerator: Optimize FindMakefile method with an index

This method is used by directory get/set APIs.  With the new
`SUBDIRECTORIES` and `BUILDSYSTEM_TARGETS` methods projects may now make
heavy use of these APIs to traverse their directory structure and
process targets.  Make this faster by indexing the directory lookups.

1 files changed, 10 insertions, 0 deletions

diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index 7bc389d878..8f1d70c1a5 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -462,13 +462,16 @@ private:
   typedef std::unordered_map<std::string, cmTarget*> TargetMap;
   typedef std::unordered_map<std::string, cmGeneratorTarget*>
     GeneratorTargetMap;
+  typedef std::unordered_map<std::string, cmMakefile*> MakefileMap;
 #else
   typedef cmsys::hash_map<std::string, cmTarget*> TargetMap;
   typedef cmsys::hash_map<std::string, cmGeneratorTarget*> GeneratorTargetMap;
+  typedef cmsys::hash_map<std::string, cmMakefile*> MakefileMap;
 #endif
 #else
   typedef std::map<std::string, cmTarget*> TargetMap;
   typedef std::map<std::string, cmGeneratorTarget*> GeneratorTargetMap;
+  typedef std::map<std::string, cmMakefile*> MakefileMap;
 #endif
   // Map efficiently from target name to cmTarget instance.
   // Do not use this structure for looping over all targets.
@@ -476,6 +479,11 @@ private:
   TargetMap TargetSearchIndex;
   GeneratorTargetMap GeneratorTargetSearchIndex;
 
+  // Map efficiently from source directory path to cmMakefile instance.
+  // Do not use this structure for looping over all directories.
+  // It may not contain all of them (see note in IndexMakefile method).
+  MakefileMap MakefileSearchIndex;
+
   cmMakefile* TryCompileOuterMakefile;
   // If you add a new map here, make sure it is copied
   // in EnableLanguagesFromGenerator
@@ -528,6 +536,8 @@ private:
 
   void ClearGeneratorMembers();
 
+  void IndexMakefile(cmMakefile* mf);
+
   virtual const char* GetBuildIgnoreErrorsFlag() const { return CM_NULLPTR; }
 
   // Cache directory content and target files to be built.