Ninja: don't pollute the rules file with useless comments

Source/cmGlobalNinjaGenerator.cxx

@@ -43,12 +43,13 @@ void cmGlobalNinjaGenerator::WriteComment(std::ostream& os,
   std::string replace = comment;
   std::string::size_type lpos = 0;
   std::string::size_type rpos;
+  os << "\n#############################################\n";
   while((rpos = replace.find('\n', lpos)) != std::string::npos)
     {
     os << "# " << replace.substr(lpos, rpos - lpos) << "\n";
     lpos = rpos + 1;
     }
-  os << "# " << replace.substr(lpos) << "\n";
+  os << "# " << replace.substr(lpos) << "\n\n";
 }
 
 static bool IsIdentChar(char c)
@@ -318,6 +319,8 @@ void cmGlobalNinjaGenerator::WriteRule(std::ostream& os,
     cmGlobalNinjaGenerator::Indent(os, 1);
     os << "generator = 1\n";
     }
+
+  os << "\n";
 }
 
 void cmGlobalNinjaGenerator::WriteVariable(std::ostream& os,
@@ -374,12 +377,21 @@ cmGlobalNinjaGenerator::cmGlobalNinjaGenerator()
   , CompileCommandsStream(0)
   , Rules()
   , AllDependencies()
+  , CommentStream(0)
 {
   // // Ninja is not ported to non-Unix OS yet.
   // this->ForceUnixPaths = true;
   this->FindMakeProgramFile = "CMakeNinjaFindMake.cmake";
+  this->ClearCommentStream();
 }
 
+void cmGlobalNinjaGenerator::ClearCommentStream()
+{
+  delete CommentStream;
+  CommentStream = new cmsys_ios::stringstream(std::ios::out);
+}
+
+
 //----------------------------------------------------------------------------
 // Virtual public methods.
 
@@ -537,7 +549,13 @@ void cmGlobalNinjaGenerator::AddRule(const std::string& name,
 {
   // Do not add the same rule twice.
   if (this->HasRule(name))
+    {
+    this->ClearCommentStream();
     return;
+    }
+
+  *this->RulesFileStream << this->GetCommentStream().str();
+  this->ClearCommentStream();
 
   this->Rules.insert(name);
   cmGlobalNinjaGenerator::WriteRule(*this->RulesFileStream,

Source/cmGlobalNinjaGenerator.h

@@ -16,6 +16,8 @@
 #  include "cmGlobalGenerator.h"
 #  include "cmNinjaTypes.h"
 
+//#define NINJA_GEN_VERBOSE_FILES
+
 class cmLocalGenerator;
 class cmGeneratedFileStream;
 class cmGeneratorTarget;
@@ -215,6 +217,11 @@ public:
   cmGeneratedFileStream* GetRulesFileStream() const
   { return this->RulesFileStream; }
 
+  void ClearCommentStream();
+  cmsys_ios::stringstream& GetCommentStream() const
+  { return *this->CommentStream; }
+
+
   void AddCXXCompileCommand(const std::string &commandLine,
                             const std::string &sourceFile);
 
@@ -346,6 +353,9 @@ private:
   static cmLocalGenerator* LocalGenerator;
 
   static bool UsingMinGW;
+
+  cmsys_ios::stringstream* CommentStream;
+
 };
 
 #endif // ! cmGlobalNinjaGenerator_h

Source/cmLocalNinjaGenerator.cxx

@@ -46,7 +46,9 @@ void cmLocalNinjaGenerator::Generate()
   this->SetConfigName();
 
   this->WriteProcessedMakefile(this->GetBuildFileStream());
+#ifdef NINJA_GEN_VERBOSE_FILES
   this->WriteProcessedMakefile(this->GetRulesFileStream());
+#endif
 
   this->WriteBuildFileTop();
 

Source/cmNinjaNormalTargetGenerator.cxx

@@ -96,13 +96,11 @@ void cmNinjaNormalTargetGenerator::Generate()
 #endif
     this->WriteLinkStatement();
     }
-
-  this->GetBuildFileStream() << "\n";
-  this->GetRulesFileStream() << "\n";
 }
 
 void cmNinjaNormalTargetGenerator::WriteLanguagesRules()
 {
+#ifdef NINJA_GEN_VERBOSE_FILES
   cmGlobalNinjaGenerator::WriteDivider(this->GetRulesFileStream());
   this->GetRulesFileStream()
     << "# Rules for each languages for "
@@ -110,6 +108,7 @@ void cmNinjaNormalTargetGenerator::WriteLanguagesRules()
     << " target "
     << this->GetTargetName()
     << "\n\n";
+#endif
 
   std::set<cmStdString> languages;
   this->GetTarget()->GetLanguages(languages);

Source/cmNinjaTargetGenerator.cxx

@@ -309,10 +309,11 @@ void
 cmNinjaTargetGenerator
 ::WriteLanguageRules(const std::string& language)
 {
+#ifdef NINJA_GEN_VERBOSE_FILES
   this->GetRulesFileStream()
     << "# Rules for language " << language << "\n\n";
+#endif
   this->WriteCompileRule(language);
-  this->GetRulesFileStream() << "\n";
 }
 
 void