svn commit: r282987 - head/sys/sys

[Pedro F. Giffuni]

Author: pfg
Date: Fri May 15 19:51:05 2015
New Revision: 282987
URL: https://svnweb.freebsd.org/changeset/base/282987

Log:
  Break apart the gnu_inline attribute and use "artificial" if available.
  
  In general it is bad practice to use the gnu_inline attribute but we
  will need it in special cases like FORTIFY_SOURCE. In this specific
  case it is also useful to have the "artificial" attribute:
  
  "This attribute is useful for small inline wrappers which if possible
  should appear during debugging as a unit, depending on the debug info
  format it will either mean marking the function as artificial or using the
  caller location for all instructions within the inlined body."
  
  This attribute appears to be currently implemented only in GCC. Use it
  only in conjuntion with gnu_inline in the cases where it is available,
  which is similar in spirit in how it's used in glibc.

Modified:
  head/sys/sys/cdefs.h

Modified: head/sys/sys/cdefs.h
==============================================================================
--- head/sys/sys/cdefs.h	Fri May 15 19:37:17 2015	(r282986)
+++ head/sys/sys/cdefs.h	Fri May 15 19:51:05 2015	(r282987)
@@ -375,10 +375,8 @@
 #endif
 
 #if __GNUC_PREREQ__(4, 1)
-#define	__gnu_inline	__attribute__((__gnu_inline__))
 #define	__returns_twice	__attribute__((__returns_twice__))
 #else
-#define	__gnu_inline
 #define	__returns_twice
 #endif
 
@@ -538,6 +536,21 @@
 	    __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
 #endif
 
+/*
+ * FORTIFY_SOURCE, and perhaps other compiler-specific features, require
+ * the use of non-standard inlining.  In general we should try to avoid
+ * using these but GCC-compatible compilers tend to support the extensions
+ * well enough to use them in limited cases.
+ */ 
+#if __GNUC_PREREQ__(4, 1)
+#if __has_attribute(artificial) || __GNUC_PREREQ__(4, 3)
+#define	__gnu_inline	__attribute__((__gnu_inline__, __artificial__))
+#else
+#define	__gnu_inline	__attribute__((__gnu_inline__))
+#else
+#define	__gnu_inline
+#endif
+
 /* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
 #if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
     defined(__GNUC__) && !defined(__INTEL_COMPILER)