New attempt to make the allocation routines 64 bit clean....

src/utils.h

Index: src/utils.h
===================================================================
--- src/utils.h	(revision 5551)
+++ src/utils.h	(working copy)
@@ -222,12 +222,22 @@
 // ----------------------------------------------------------------------------
 // I/O support.
 
-// Our version of printf(). Avoids compilation errors that we get
-// with standard printf when attempting to print pointers, etc.
-// (the errors are due to the extra compilation flags, which we
-// want elsewhere).
-void PrintF(const char* format, ...);
+#if __GNUC__ >= 4
+// On gcc we can ask the compiler to check the types of %d-style format
+// specifiers and their associated arguments.  TODO(erikcorry) fix this
+// so it works on MacOSX.
+#if defined(__MACH__) && defined(__APPLE__)
+#define PRINTF_CHECKING
+#else  // MacOsX.
+#define PRINTF_CHECKING __attribute__ ((format (printf, 1, 2)))
+#endif
+#else
+#define PRINTF_CHECKING
+#endif
 
+// Our version of printf().
+void PRINTF_CHECKING PrintF(const char* format, ...);
+
 // Our version of fflush.
 void Flush();