From feecde4aaa0c3bf6644ddeec0dfd101d3cf6fd74 Mon Sep 17 00:00:00 2001
From: David Jones <drj@ravenbrook.com>
Date: Thu, 19 Apr 2007 11:32:08 +0100
Subject: [PATCH] Added diag and diag_writef

Copied from Perforce
 Change: 162160
 ServerID: perforce.ravenbrook.com
---
 mps/code/mpm.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/mps/code/mpm.h b/mps/code/mpm.h
index edd4a2e5dbe..2279b7ed2b7 100644
--- a/mps/code/mpm.h
+++ b/mps/code/mpm.h
@@ -945,6 +945,28 @@ extern void StackProbe(Size depth);
 
 #endif
 
+/* Diagnostics */
+
+Bool DiagIsOn(void);
+
+#define DIAG_STREAM (DiagStream())
+
+#define DIAG(s) BEGIN \
+    s \
+  END
+
+/*
+ * Note the macro argument args should have parens around it (in the
+ * invocation); it is a variable number of arguments that we pass
+ * to another function.
+ * That makes this macro unclean in all sorts of ways.
+ */
+#define DIAG_WRITEF(stream, args) DIAG( \
+  if(DiagIsOn()) { \
+    WriteF a; \
+  } \
+)
+
 
 #endif /* mpm_h */