From 0be0bb57b2e79209cd57b453fa349377f8d9b9ac Mon Sep 17 00:00:00 2001
From: Royce Mitchell III <royce3@ev1.net>
Date: Tue, 8 Mar 2005 17:14:07 +0000
Subject: [PATCH] detect PCH support ( not doing anything more than detection
 yet )

svn path=/branches/xmlbuildsystem/; revision=13878
---
 reactos/tools/rbuild/backend/mingw/mingw.cpp  | 23 +++++++++++++++++++
 reactos/tools/rbuild/backend/mingw/mingw.h    |  3 +++
 .../rbuild/backend/mingw/pch_detection.h      |  1 +
 3 files changed, 27 insertions(+)
 create mode 100644 reactos/tools/rbuild/backend/mingw/pch_detection.h

diff --git a/reactos/tools/rbuild/backend/mingw/mingw.cpp b/reactos/tools/rbuild/backend/mingw/mingw.cpp
index 4e1a5f5d4e1..0773f0e6321 100644
--- a/reactos/tools/rbuild/backend/mingw/mingw.cpp
+++ b/reactos/tools/rbuild/backend/mingw/mingw.cpp
@@ -26,6 +26,8 @@ MingwBackend::MingwBackend ( Project& project )
 void
 MingwBackend::Process ()
 {
+	DetectPCHSupport();
+
 	CreateMakefile ();
 	GenerateHeader ();
 	GenerateGlobalVariables ();
@@ -323,3 +325,24 @@ FixupTargetFilename ( const string& targetFilename )
 {
 	return string("$(ROS_INTERMEDIATE)") + NormalizeFilename ( targetFilename );
 }
+
+void
+MingwBackend::DetectPCHSupport()
+{
+	string path = "tools" SSEP "rbuild" SSEP "backend" SSEP "mingw" SSEP "pch_detection.h";
+	system ( ssprintf("gcc -c %s", path.c_str()).c_str() );
+	path += ".gch";
+	{
+		FILE* f = fopen ( path.c_str(), "rb" );
+		if ( f )
+		{
+			use_pch = true;
+			fclose(f);
+			unlink ( path.c_str() );
+		}
+		else
+			use_pch = false;
+	}
+	// TODO FIXME - eventually check for ROS_USE_PCH env var and
+	// allow that to override use_pch if true
+}
diff --git a/reactos/tools/rbuild/backend/mingw/mingw.h b/reactos/tools/rbuild/backend/mingw/mingw.h
index 604176e0cc8..7d4c5a7d978 100644
--- a/reactos/tools/rbuild/backend/mingw/mingw.h
+++ b/reactos/tools/rbuild/backend/mingw/mingw.h
@@ -32,7 +32,10 @@ private:
 	void GenerateInitTarget () const;
 	void GenerateXmlBuildFilesMacro() const;
 	void CheckAutomaticDependencies ();
+	void DetectPCHSupport();
+
 	FILE* fMakefile;
+	bool use_pch;
 };
 
 std::string FixupTargetFilename ( const std::string& targetFilename );
diff --git a/reactos/tools/rbuild/backend/mingw/pch_detection.h b/reactos/tools/rbuild/backend/mingw/pch_detection.h
new file mode 100644
index 00000000000..4c883e0aaa7
--- /dev/null
+++ b/reactos/tools/rbuild/backend/mingw/pch_detection.h
@@ -0,0 +1 @@
+// this file is intentionally left empty
\ No newline at end of file