yann@1: From http://sources.redhat.com/ml/libc-alpha/2002-06/msg00006.html
yann@1: 
yann@1: Message-ID: <15612.44195.299251.921969@honolulu.ilog.fr>
yann@1: Date: Tue, 4 Jun 2002 14:03:47 +0200 (CEST)
yann@1: From: Bruno Haible <bruno at clisp dot org>
yann@1: To: libc-alpha at sources dot redhat dot com
yann@1: Subject: link_warning fix
yann@1: 
yann@1: 
yann@1: Hi,
yann@1: 
yann@1: While cross-compiling glibc-2.2.5 for target=cris-linux using gcc-3.1 and
yann@1: binutils-2.12.90.0.7, I get an error
yann@1: 
yann@1: cris-linux-gcc ../sysdeps/unix/sysv/linux/sigstack.c -c -O2 -Wall -Winline -Wstrict-prototypes -Wwrite-strings -g      -I../include -I. -I/backup/cross-build/build-glibc-cris/signal -I.. -I../libio  -I/backup/cross-build/build-glibc-cris -I../sysdeps/cris/elf -I../linuxthreads/sysdeps/unix/sysv/linux -I../linuxthreads/sysdeps/pthread -I../sysdeps/pthread -I../linuxthreads/sysdeps/unix/sysv -I../linuxthreads/sysdeps/unix -I../linuxthreads/sysdeps/cris -I../sysdeps/unix/sysv/linux/cris -I../sysdeps/unix/sysv/linux -I../sysdeps/gnu -I../sysdeps/unix/common -I../sysdeps/unix/mman -I../sysdeps/unix/inet -I../sysdeps/unix/sysv -I../sysdeps/unix -I../sysdeps/posix -I../sysdeps/cris -I../sysdeps/wordsize-32 -I../sysdeps/ieee754/flt-32 -I../sysdeps/ieee754/dbl-64 -I../sysdeps/ieee754 -I../sysdeps/generic/elf -I../sysdeps/generic  -nostdinc -isystem /cross/cris-linux-tools/lib/gcc-lib/cris-linux/3.1/include -isystem /cross/cris-linux/include -D_LIBC_REENTRANT -include ../include/libc-symbols.h     -o /backup/cross-build/build-glibc-cris/signal/sigstack.o
yann@1: /tmp/cca7qZyI.s: Assembler messages:
yann@1: /tmp/cca7qZyI.s:87: Warning: rest of line ignored; first ignored character is `,'
yann@1: /tmp/cca7qZyI.s:87: Error: Unknown opcode: `progbits'
yann@1: make[2]: *** [/backup/cross-build/build-glibc-cris/signal/sigstack.o] Fehler 1
yann@1: 
yann@1: 
yann@1: The reason is that the .s file contains the following.
yann@1: 
yann@1: ...
yann@1: 	.size	sigstack,.Lfe1-sigstack
yann@1: #APP
yann@1: 	.section .gnu.warning.sigstack
yann@1: 	.previous
yann@1: #NO_APP
yann@1: 	.section	.gnu.warning.sigstack
yann@1: 	#,"a",@progbits
yann@1: 	.align 2
yann@1: 	.type	__evoke_link_warning_sigstack,@object
yann@1: ...
yann@1: 
yann@1: and comments (introduced by '#') are recognized by the assembler only after
yann@1: #APP, not after #NO_APP. The workaround is to add '#APP' to the fake section
yann@1: name. The following patch works for me.
yann@1: 
yann@1: 2002-06-02  Bruno Haible  <bruno@clisp.org>
yann@1: 
yann@1: 	* include/libc-symbols.h (__as_app_line): New macro.
yann@1: 	(link_warning): Emit #APP line to turn comment recognition on.
yann@1: 
yann@1: *** glibc-2.2.5/include/libc-symbols.h.bak	2001-08-04 01:02:52.000000000 +0200
yann@1: --- glibc-2.2.5/include/libc-symbols.h	2002-06-02 16:22:15.000000000 +0200
yann@1: ***************
yann@1: *** 207,224 ****
yann@1:   #   define __make_section_unallocated(section_string)
yann@1:   #  endif
yann@1:   
yann@1: ! /* Tacking on "\n\t#" to the section name makes gcc put it's bogus
yann@1: !    section attributes on what looks like a comment to the assembler.  */
yann@1:   #  ifdef HAVE_SECTION_QUOTES
yann@1:   #   define link_warning(symbol, msg) \
yann@1:     __make_section_unallocated (".gnu.warning." #symbol) \
yann@1: !   static const char __evoke_link_warning_##symbol[]	\
yann@1: !     __attribute__ ((section (".gnu.warning." #symbol "\"\n\t#\""))) = msg;
yann@1:   #  else
yann@1:   #   define link_warning(symbol, msg) \
yann@1:     __make_section_unallocated (".gnu.warning." #symbol) \
yann@1: !   static const char __evoke_link_warning_##symbol[]	\
yann@1: !     __attribute__ ((section (".gnu.warning." #symbol "\n\t#"))) = msg;
yann@1:   #  endif
yann@1:   # else /* Not ELF: a.out */
yann@1:   #  ifdef HAVE_XCOFF
yann@1: --- 207,235 ----
yann@1:   #   define __make_section_unallocated(section_string)
yann@1:   #  endif
yann@1:   
yann@1: ! /* Tacking on "\n\t#" to the section name makes gcc put its bogus
yann@1: !    section attributes on what looks like a comment to the assembler.
yann@1: !    Furthermore, with gas, we need to add a "#APP" line so the comment
yann@1: !    is recognized as such.  */
yann@1: ! #  ifdef HAVE_GNU_AS
yann@1: ! #   define __as_app_line "#APP\n"
yann@1: ! #  else
yann@1: ! #   define __as_app_line ""
yann@1: ! #  endif
yann@1:   #  ifdef HAVE_SECTION_QUOTES
yann@1:   #   define link_warning(symbol, msg) \
yann@1:     __make_section_unallocated (".gnu.warning." #symbol) \
yann@1: !   static const char __evoke_link_warning_##symbol[]			 \
yann@1: !     __attribute__							 \
yann@1: !       ((section (".gnu.warning." #symbol "\"\n" __as_app_line "\t#\""))) \
yann@1: !     = msg;
yann@1:   #  else
yann@1:   #   define link_warning(symbol, msg) \
yann@1:     __make_section_unallocated (".gnu.warning." #symbol) \
yann@1: !   static const char __evoke_link_warning_##symbol[]			\
yann@1: !     __attribute__							\
yann@1: !       ((section (".gnu.warning." #symbol "\n" __as_app_line "\t#")))	\
yann@1: !     = msg;
yann@1:   #  endif
yann@1:   # else /* Not ELF: a.out */
yann@1:   #  ifdef HAVE_XCOFF
yann@1: