From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Subject: Re: [RFC 1/2] Change how the symbol_version_reference macro is defined
Date: Fri, 19 Mar 2021 15:47:22 -0300 [thread overview]
Message-ID: <564b88b3-7010-69ea-f02f-668d982642fb@linaro.org> (raw)
In-Reply-To: <0f5cee98e3474cbcf1d699334b2d9e993f1c3776.1616095061.git.fweimer@redhat.com>
On 18/03/2021 17:07, Florian Weimer via Libc-alpha wrote:
> A subsequent change will require including <config.h> for defining
> symbol_version_reference. <libc-symbol.h> should not include
> <config.h> for _ISOMAC, so it cannot define symbol_version_reference
> anymore, but symbol_version_reference is needed <shlib-compat.h> even
> for _ISOMAC. Moving the definition of symbol_version_reference to a
> separate file <libc-symver.h> makes it possible to use a single
> definition for both cases.
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> include/libc-symbols.h | 16 +++-------------
> include/libc-symver.h | 38 ++++++++++++++++++++++++++++++++++++++
> include/shlib-compat.h | 3 +++
> 3 files changed, 44 insertions(+), 13 deletions(-)
> create mode 100644 include/libc-symver.h
>
> diff --git a/include/libc-symbols.h b/include/libc-symbols.h
> index c83e550b03..ce5f75a1a2 100644
> --- a/include/libc-symbols.h
> +++ b/include/libc-symbols.h
> @@ -59,19 +59,6 @@
> # define IN_MODULE (-1)
> #endif
>
> -/* Use symbol_version_reference to specify the version a symbol
> - reference should link to. Use symbol_version or
> - default_symbol_version for the definition of a versioned symbol.
> - The difference is that the latter is a no-op in non-shared
> - builds. */
> -#ifdef __ASSEMBLER__
> -# define symbol_version_reference(real, name, version) \
> - .symver real, name##@##version
> -#else /* !__ASSEMBLER__ */
> -# define symbol_version_reference(real, name, version) \
> - __asm__ (".symver " #real "," #name "@" #version)
> -#endif
> -
> #ifndef _ISOMAC
>
> /* This is defined for the compilation of all C library code. features.h
Ok.
> @@ -97,6 +84,9 @@
>
> #include <config.h>
>
> +/* Obtain the definition of symbol_version_reference. */
> +#include <libc-symver.h>
> +
> /* When PIC is defined and SHARED isn't defined, we are building PIE
> by default. */
> #if defined PIC && !defined SHARED
Ok.
> diff --git a/include/libc-symver.h b/include/libc-symver.h
> new file mode 100644
> index 0000000000..11c77ae1cd
> --- /dev/null
> +++ b/include/libc-symver.h
> @@ -0,0 +1,38 @@
> +/* Symbol version management.
> + Copyright (C) 1995-2021 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +/* This file is included from <libc-symbols.h> for !_ISOMAC, and
> + unconditionally from <shlib-compat.h>. */
> +
> +#ifndef _LIBC_SYMVER_H
> +#define _LIBC_SYMVER_H 1
> +
> +/* Use symbol_version_reference to specify the version a symbol
> + reference should link to. Use symbol_version or
> + default_symbol_version for the definition of a versioned symbol.
> + The difference is that the latter is a no-op in non-shared
> + builds. */
> +#ifdef __ASSEMBLER__
> +# define symbol_version_reference(real, name, version) \
> + .symver real, name##@##version
> +#else /* !__ASSEMBLER__ */
> +# define symbol_version_reference(real, name, version) \
> + __asm__ (".symver " #real "," #name "@" #version)
> +#endif
> +
> +#endif /* _LIBC_SYMVER_H */
Ok.
> diff --git a/include/shlib-compat.h b/include/shlib-compat.h
> index 28baef1ea4..b874e2588f 100644
> --- a/include/shlib-compat.h
> +++ b/include/shlib-compat.h
> @@ -21,6 +21,9 @@
>
> # include <abi-versions.h>
>
> +/* Obtain the definition of symbol_version_reference. */
> +#include <libc-symver.h>
> +
> /* The file abi-versions.h (generated by scripts/abi-versions.awk) defines
> symbols like `ABI_libm_GLIBC_2_0' for each version set in the source
> code for each library. For a version set that is subsumed by a later
>
Ok.
next prev parent reply other threads:[~2021-03-19 18:47 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 20:06 [RFC 0/2] Transparent multi-version symbol support Florian Weimer
2021-03-18 20:07 ` [RFC 1/2] Change how the symbol_version_reference macro is defined Florian Weimer
2021-03-19 18:47 ` Adhemerval Zanella [this message]
2021-03-18 20:07 ` [RFC 2/2] Fold compat_symbol_unique functionality into compat_symbol Florian Weimer
2021-03-18 21:37 ` Joseph Myers
2021-03-19 18:59 ` Adhemerval Zanella
2021-03-19 19:13 ` Florian Weimer
2021-03-19 19:34 ` Adhemerval Zanella
2021-03-19 20:10 ` Adhemerval Zanella
2021-03-19 20:17 ` Florian Weimer
2021-03-19 20:26 ` Adhemerval Zanella
2021-03-19 20:29 ` Florian Weimer
2021-03-19 20:33 ` Adhemerval Zanella
2021-03-19 20:33 ` Adhemerval Zanella
2021-03-19 19:02 ` [RFC 0/2] Transparent multi-version symbol support Adhemerval Zanella
2021-03-19 19:14 ` Florian Weimer
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