[glibc/release/2.35/master] cdefs: Limit definition of fortification macros

[Siddhesh Poyarekar <siddhesh@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=ae045ed16b351038f66fcabbab7b4670a7381ab5

commit ae045ed16b351038f66fcabbab7b4670a7381ab5
Author: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date:   Thu Feb 2 07:49:02 2023 -0500

    cdefs: Limit definition of fortification macros
    
    Define the __glibc_fortify and other macros only when __FORTIFY_LEVEL >
    0.  This has the effect of not defining these macros on older C90
    compilers that do not have support for variable length argument lists.
    
    Also trim off the trailing backslashes from the definition of
    __glibc_fortify and __glibc_fortify_n macros.
    
    Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
    Reviewed-by: Florian Weimer <fweimer@redhat.com>
    (cherry picked from commit 2337e04e21ba6040926ec871e403533f77043c40)

Diff:
---
 misc/sys/cdefs.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index 1c2b044a0d..1e136bfd83 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -152,6 +152,7 @@
 # define __glibc_objsize(__o) __bos (__o)
 #endif
 
+#if __USE_FORTIFY_LEVEL > 0
 /* Compile time conditions to choose between the regular, _chk and _chk_warn
    variants.  These conditions should get evaluated to constant and optimized
    away.  */
@@ -187,7 +188,7 @@
    ? __ ## f ## _alias (__VA_ARGS__)					      \
    : (__glibc_unsafe_len (__l, __s, __osz)				      \
       ? __ ## f ## _chk_warn (__VA_ARGS__, __osz)			      \
-      : __ ## f ## _chk (__VA_ARGS__, __osz)))			      \
+      : __ ## f ## _chk (__VA_ARGS__, __osz)))
 
 /* Fortify function f, where object size argument passed to f is the number of
    elements and not total size.  */
@@ -197,7 +198,8 @@
    ? __ ## f ## _alias (__VA_ARGS__)					      \
    : (__glibc_unsafe_len (__l, __s, __osz)				      \
       ? __ ## f ## _chk_warn (__VA_ARGS__, (__osz) / (__s))		      \
-      : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))))		      \
+      : __ ## f ## _chk (__VA_ARGS__, (__osz) / (__s))))
+#endif
 
 #if __GNUC_PREREQ (4,3)
 # define __warnattr(msg) __attribute__((__warning__ (msg)))