Major optimization of C/C++ dependency scanning.

Now only the dependencies for the file where the dependencies actually may
have changed are rescanned, before that this was done for all source files
even if only one source file had changed.
This reduces e.g. on my machine the time for scanning the dependencies
of kdelibs/khtml/ when only one file (khtml_global.cpp) has changed from
around 7.5 seconds to 1.2 seconds.

The tests succeed, it does what I expected it to do on kdelibs, and Brad
also reviewed the patch, so I think it should be ok.

Alex

1 files changed, 3 insertions, 1 deletions

diff --git a/Source/cmDependsC.h b/Source/cmDependsC.h
index dafb112eb9..0830ccaf44 100644
--- a/Source/cmDependsC.h
+++ b/Source/cmDependsC.h
@@ -30,7 +30,8 @@ public:
   /** Checking instances need to know the build directory name and the
       relative path from the build directory to the target file.  */
   cmDependsC();
-  cmDependsC(cmLocalGenerator* lg, const char* targetDir, const char* lang);
+  cmDependsC(cmLocalGenerator* lg, const char* targetDir, const char* lang,
+             const std::map<std::string, DependencyVector>* validDeps);
 
   /** Virtual destructor to cleanup subclasses properly.  */
   virtual ~cmDependsC();
@@ -83,6 +84,7 @@ public:
     bool Used;
   };
 protected:
+  const std::map<std::string, DependencyVector>* ValidDeps;
   std::set<cmStdString> Encountered;
   std::queue<UnscannedEntry> Unscanned;
   t_CharBuffer Buffer;