From c5ac2b9df36a57d3b88e80a2d1c382d753faf2da Mon Sep 17 00:00:00 2001
From: James Johnston <johnstonj.public@codenest.com>
Date: Sat, 8 Aug 2015 20:04:08 +0000
Subject: [PATCH 1/2] Ninja: Centralized required Ninja version numbers and
 comparisons.

---
 Source/cmGlobalNinjaGenerator.cxx |  7 ++++---
 Source/cmGlobalNinjaGenerator.h   |  6 ++++--
 Source/cmLocalNinjaGenerator.cxx  | 12 +++++-------
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index 088f0e1e7..b46d85c1b 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -1256,7 +1256,7 @@ std::string cmGlobalNinjaGenerator::ninjaCmd() const
   return "ninja";
 }
 
-std::string cmGlobalNinjaGenerator::ninjaVersion() const
+std::string cmGlobalNinjaGenerator::CurrentNinjaVersion() const
 {
   std::string version;
   std::string command = ninjaCmd() + " --version";
@@ -1264,13 +1264,14 @@ std::string cmGlobalNinjaGenerator::ninjaVersion() const
                                   &version, 0, 0, 0,
                                   cmSystemTools::OUTPUT_NONE);
 
-  return version;
+  return cmSystemTools::TrimWhitespace(version);
 }
 
 bool cmGlobalNinjaGenerator::SupportsConsolePool() const
 {
   return cmSystemTools::VersionCompare(cmSystemTools::OP_LESS,
-                                       ninjaVersion().c_str(), "1.5") == false;
+    CurrentNinjaVersion().c_str(),
+    RequiredNinjaVersionForConsolePool().c_str()) == false;
 }
 
 void cmGlobalNinjaGenerator::WriteTargetClean(std::ostream& os)
diff --git a/Source/cmGlobalNinjaGenerator.h b/Source/cmGlobalNinjaGenerator.h
index 2a749c1f7..a1df1c277 100644
--- a/Source/cmGlobalNinjaGenerator.h
+++ b/Source/cmGlobalNinjaGenerator.h
@@ -299,8 +299,10 @@ public:
 
   virtual void ComputeTargetObjectDirectory(cmGeneratorTarget* gt) const;
 
-  std::string ninjaVersion() const;
-
+  std::string CurrentNinjaVersion() const;
+  // Ninja generator uses 'deps' and 'msvc_deps_prefix' introduced in 1.3
+  static std::string RequiredNinjaVersion() { return "1.3"; }
+  static std::string RequiredNinjaVersionForConsolePool() { return "1.5"; }
   bool SupportsConsolePool() const;
 
 protected:
diff --git a/Source/cmLocalNinjaGenerator.cxx b/Source/cmLocalNinjaGenerator.cxx
index 9889bd4c2..aaad07585 100644
--- a/Source/cmLocalNinjaGenerator.cxx
+++ b/Source/cmLocalNinjaGenerator.cxx
@@ -193,16 +193,14 @@ void cmLocalNinjaGenerator::WriteProjectHeader(std::ostream& os)
 void cmLocalNinjaGenerator::WriteNinjaRequiredVersion(std::ostream& os)
 {
   // Default required version
-  // Ninja generator uses 'deps' and 'msvc_deps_prefix' introduced in 1.3
-  std::string requiredVersion = "1.3";
+  std::string requiredVersion =
+      this->GetGlobalNinjaGenerator()->RequiredNinjaVersion();
 
   // Ninja generator uses the 'console' pool if available (>= 1.5)
-  std::string usedVersion = this->GetGlobalNinjaGenerator()->ninjaVersion();
-  if(cmSystemTools::VersionCompare(cmSystemTools::OP_LESS,
-                                   usedVersion.c_str(),
-                                   "1.5") ==  false)
+  if(this->GetGlobalNinjaGenerator()->SupportsConsolePool())
     {
-      requiredVersion = "1.5";
+    requiredVersion =
+      this->GetGlobalNinjaGenerator()->RequiredNinjaVersionForConsolePool();
     }
 
   cmGlobalNinjaGenerator::WriteComment(os,

From 874e70bc57f54e5fc898a169797a0b1e45df31f6 Mon Sep 17 00:00:00 2001
From: James Johnston <johnstonj.public@codenest.com>
Date: Sun, 9 Aug 2015 13:51:35 -0400
Subject: [PATCH 2/2] Ninja: Prevent generating if installed Ninja version is
 too old.

---
 Source/cmGlobalNinjaGenerator.cxx | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index b46d85c1b..b92ad32c9 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -547,6 +547,18 @@ void cmGlobalNinjaGenerator
 //   Source/cmake.cxx
 void cmGlobalNinjaGenerator::Generate()
 {
+  // Check minimum Ninja version.
+  if (cmSystemTools::VersionCompare(cmSystemTools::OP_LESS,
+                                    CurrentNinjaVersion().c_str(),
+                                    RequiredNinjaVersion().c_str()))
+    {
+    std::ostringstream msg;
+    msg << "The detected version of Ninja (" << this->CurrentNinjaVersion();
+    msg << ") is less than the version of Ninja required by CMake (";
+    msg << this->RequiredNinjaVersion() << ").";
+    this->GetCMakeInstance()->IssueMessage(cmake::FATAL_ERROR, msg.str());
+    return;
+    }
   this->OpenBuildFileStream();
   this->OpenRulesFileStream();