[src/trunk]: src/sys/sys Implement __warn_references and __SECTIONSTRING (use...

[joerg <joerg%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/846373157228
branches:  trunk
changeset: 759387:846373157228
user:      joerg <joerg%NetBSD.org@localhost>
date:      Wed Dec 08 01:18:55 2010 +0000

description:
Implement __warn_references and __SECTIONSTRING (used e.g. by __RCSID)
for clang without assembler. This declares a global variable with
attribute used to prevent optimisation, attribute section to change
the placement and includes __COUNTER__ in the variable name for
uniqueness.

diffstat:

 sys/sys/cdefs_elf.h |  14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diffs (39 lines):

diff -r e49b31fccaac -r 846373157228 sys/sys/cdefs_elf.h
--- a/sys/sys/cdefs_elf.h       Wed Dec 08 00:25:54 2010 +0000
+++ b/sys/sys/cdefs_elf.h       Wed Dec 08 01:18:55 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cdefs_elf.h,v 1.33 2010/10/12 06:39:48 skrll Exp $     */
+/*     $NetBSD: cdefs_elf.h,v 1.34 2010/12/08 01:18:55 joerg Exp $     */
 
 /*
  * Copyright (c) 1995, 1996 Carnegie-Mellon University.
@@ -70,10 +70,16 @@
 #define        __weak_reference(sym)   ; __asm(".weak " _C_LABEL_STRING(#sym))
 #endif
 
+#if defined(__clang__)
+#define        __warn_references(sym,msg)                                      \
+    static __attribute__((__used__, __section__(".gnu.warning." #sym))) \
+    const char ___CONCAT(__warn_reference_##sym,__COUNTER__)[] = msg;
+#else
 #define        __warn_references(sym,msg)                                      \
     __asm(".pushsection .gnu.warning." #sym "\n"                       \
          ".ascii \"" msg "\"\n"                                        \
          ".popsection");
+#endif
 
 #else /* !__STDC__ */
 
@@ -100,7 +106,11 @@
 
 #endif /* !__STDC__ */
 
-#if __STDC__
+#if defined(__clang__)
+#define        __SECTIONSTRING(_sec, _str)                                     \
+       static __attribute__((__used__, __section__(#_sec))) const char \
+       ___CONCAT(__sectstr,__COUNTER__)[] = _str
+#elif __STDC__
 #define        __SECTIONSTRING(_sec, _str)                                     \
        __asm(".pushsection " #_sec "\n"                                \
              ".asciz \"" _str "\"\n"                                   \