[RFC,1/2] Change how the symbol_version_reference macro is defined
Commit Message
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.
---
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
Comments
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.
@@ -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
@@ -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
new file mode 100644
@@ -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 */
@@ -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