cmTarget: Cache the cmSourceFiles in GetSourceFiles.

Avoid calling GetSourceFiles with the same result container multiple
times when tracing target dependencies.  The result from the previous
configuration is cached and used later otherwise.

1 files changed, 30 insertions, 9 deletions

diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index 22be57f..d28ac3f 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -138,6 +138,10 @@ public:
                                                           LinkClosureMapType;
   LinkClosureMapType LinkClosureMap;
 
+  typedef std::map<TargetConfigPair, std::vector<cmSourceFile*> >
+                                                          SourceFilesMapType;
+  SourceFilesMapType SourceFilesMap;
+
   struct TargetPropertyEntry {
     TargetPropertyEntry(cmsys::auto_ptr<cmCompiledGeneratorExpression> cge,
       const std::string &targetName = std::string())
@@ -793,19 +797,33 @@ void cmTarget::GetSourceFiles(std::vector<cmSourceFile*> &files,
                               const std::string& config,
                               cmTarget const* head) const
 {
-  std::vector<std::string> srcs;
-  this->GetSourceFiles(srcs, config, head);
 
-  std::set<cmSourceFile*> emitted;
+  // Lookup any existing link implementation for this configuration.
+  TargetConfigPair key(head, cmSystemTools::UpperCase(config));
 
-  for(std::vector<std::string>::const_iterator i = srcs.begin();
-      i != srcs.end(); ++i)
+  cmTargetInternals::SourceFilesMapType::iterator
+    it = this->Internal->SourceFilesMap.find(key);
+  if(it != this->Internal->SourceFilesMap.end())
+    {
+    files = it->second;
+    }
+  else
     {
-    cmSourceFile* sf = this->Makefile->GetOrCreateSource(*i);
-    if (emitted.insert(sf).second)
+    std::vector<std::string> srcs;
+    this->GetSourceFiles(srcs, config, head);
+
+    std::set<cmSourceFile*> emitted;
+
+    for(std::vector<std::string>::const_iterator i = srcs.begin();
+        i != srcs.end(); ++i)
       {
-      files.push_back(sf);
+      cmSourceFile* sf = this->Makefile->GetOrCreateSource(*i);
+      if (emitted.insert(sf).second)
+        {
+        files.push_back(sf);
+        }
       }
+    this->Internal->SourceFilesMap[key] = files;
     }
 }
 
@@ -835,6 +853,7 @@ void cmTarget::AddSources(std::vector<std::string> const& srcs)
     }
   if (!srcFiles.empty())
     {
+    this->Internal->SourceFilesMap.clear();
     cmListFileBacktrace lfbt;
     this->Makefile->GetBacktrace(lfbt);
     cmGeneratorExpression ge(lfbt);
@@ -969,6 +988,7 @@ cmSourceFile* cmTarget::AddSource(const std::string& src)
                    TargetPropertyEntryFinder(sfl))
                                       == this->Internal->SourceEntries.end())
     {
+    this->Internal->SourceFilesMap.clear();
     cmListFileBacktrace lfbt;
     this->Makefile->GetBacktrace(lfbt);
     cmGeneratorExpression ge(lfbt);
@@ -1738,6 +1758,7 @@ void cmTarget::SetProperty(const std::string& prop, const char* value)
       this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
       return;
       }
+    this->Internal->SourceFilesMap.clear();
     cmListFileBacktrace lfbt;
     this->Makefile->GetBacktrace(lfbt);
     cmGeneratorExpression ge(lfbt);
@@ -1824,7 +1845,7 @@ void cmTarget::AppendProperty(const std::string& prop, const char* value,
       this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
       return;
       }
-
+      this->Internal->SourceFilesMap.clear();
       cmListFileBacktrace lfbt;
       this->Makefile->GetBacktrace(lfbt);
       cmGeneratorExpression ge(lfbt);