Mark __libc_freeres_fn as used [BZ #27002]

GCC 11 with

commit 6fbec038f7a7ddf29f074943611b53210d17c40c
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Mon Feb 3 11:55:43 2020 -0800

    Use SHF_GNU_RETAIN to preserve symbol definitions

places used symbols in SECTION_RETAIN sections if assembler supports it.
Mark __libc_freeres_fn as used to avoid

gconv_dl.c: In function 'free_mem':
gconv_dl.c:191:1: error: 'do_release_all' without 'used' attribute and 'free_mem' with 'used' attribute are placed in a section with the same name [-Werror=attributes]
  191 | do_release_all (void *nodep)
      | ^~~~~~~~~~~~~~
In file included from <command-line>:
gconv_dl.c:202:18: note: 'free_mem' was declared here
  202 | libc_freeres_fn (free_mem)
      |                  ^~~~~~~~
./../include/libc-symbols.h:316:15: note: in definition of macro 'libc_freeres_fn'
  316 |   static void name (void)
      |               ^~~~
cc1: all warnings being treated as errors

diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index 154a73b5e54edd45ddd0b4f304fa3d7f3e47b15a..f06ce3053ab4d8ffcd5b489cdbc35b570360b000 100644 (file)
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -307,7 +307,7 @@ for linking")
 
 /* Resource freeing functions from libc.so go in this section.  */
 #define __libc_freeres_fn_section \
-  __attribute__ ((section ("__libc_freeres_fn")))
+  __attribute__ ((__used__, section ("__libc_freeres_fn")))
 
 /* Resource freeing functions for libc.so.  */
 #define libc_freeres_fn(name) \