[PATCH] Don't use __BEGIN_DECLS macros from glibc.

[PATCH] Don't use __BEGIN_DECLS macros from glibc.

[Érico Nogueira]

From: Érico Rolim <erico.erc@gmail.com>

These macros are mostly internal to glibc and require the inclusion of
<sys/cdefs.h> (here included indirectly via <features.h>), which isn't a
standard header.

Since they are only required once, replacing them with their definition
is simple.

Signed-off-by: Érico Rolim <erico.erc@gmail.com>
---
 libelf/elf.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/libelf/elf.h b/libelf/elf.h
index ff9f1dad..38391392 100644
--- a/libelf/elf.h
+++ b/libelf/elf.h
@@ -19,9 +19,9 @@
 #ifndef _ELF_H
 #define	_ELF_H 1
 
-#include <features.h>
-
-__BEGIN_DECLS
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /* Standard ELF types.  */
 
@@ -4105,6 +4105,8 @@ enum
 #define R_ARC_TLS_LE_S9		0x4a
 #define R_ARC_TLS_LE_32		0x4b
 
-__END_DECLS
+#ifdef __cplusplus
+}
+#endif
 
 #endif	/* elf.h */
-- 
2.29.0

Re: [PATCH] Don't use __BEGIN_DECLS macros from glibc.

[Dmitry V. Levin]

On Mon, Oct 26, 2020 at 05:44:24PM -0300, Érico Nogueira via Elfutils-devel wrote:
> From: Érico Rolim <erico.erc@gmail.com>
> 
> These macros are mostly internal to glibc and require the inclusion of
> <sys/cdefs.h> (here included indirectly via <features.h>), which isn't a
> standard header.
> 
> Since they are only required once, replacing them with their definition
> is simple.
> 
> Signed-off-by: Érico Rolim <erico.erc@gmail.com>
> ---
>  libelf/elf.h | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)

This file is a verbatim copy of glibc's elf/elf.h, see
git log -- libelf/elf.h


-- 
ldv

Re: [PATCH] Don't use __BEGIN_DECLS macros from glibc.

[Érico Nogueira]

On Mon Oct 26, 2020 at 8:58 PM -03, Dmitry V. Levin wrote:
> On Mon, Oct 26, 2020 at 05:44:24PM -0300, Érico Nogueira via
> Elfutils-devel wrote:
> > From: Érico Rolim <erico.erc@gmail.com>
> > 
> > These macros are mostly internal to glibc and require the inclusion of
> > <sys/cdefs.h> (here included indirectly via <features.h>), which isn't a
> > standard header.
> > 
> > Since they are only required once, replacing them with their definition
> > is simple.
> > 
> > Signed-off-by: Érico Rolim <erico.erc@gmail.com>
> > ---
> >  libelf/elf.h | 10 ++++++----
> >  1 file changed, 6 insertions(+), 4 deletions(-)
>
> This file is a verbatim copy of glibc's elf/elf.h, see
> git log -- libelf/elf.h
>
>
> --
> ldv

Hm, I see. This change would only make it necessary to restore the top
and bottom of the file after any update; do you think that would be too
much trouble? I could also add a comment to make it clear why the
explicit `extern "C"` is necessary.

Thanks,
Érico

Re: [PATCH] Don't use __BEGIN_DECLS macros from glibc.

[Mark Wielaard]

Hi,

On Mon, 2020-10-26 at 18:34 -0300, Érico Nogueira via Elfutils-devel
wrote:
> On Mon Oct 26, 2020 at 8:58 PM -03, Dmitry V. Levin wrote:
> > On Mon, Oct 26, 2020 at 05:44:24PM -0300, Érico Nogueira via
> > Elfutils-devel wrote:
> > > ---
> > >  libelf/elf.h | 10 ++++++----
> > >  1 file changed, 6 insertions(+), 4 deletions(-)
> > 
> > This file is a verbatim copy of glibc's elf/elf.h, see
> > git log -- libelf/elf.h
> > 
> 
> Hm, I see. This change would only make it necessary to restore the top
> and bottom of the file after any update; do you think that would be too
> much trouble? I could also add a comment to make it clear why the
> explicit `extern "C"` is necessary.

Please just suggest a patch upstream to libc-alpha@sourceware.org.
We'll pick it up when they decide to accept it. Note that it is also a
public glibc header installed as /usr/include/elf.h.

Thanks,

Mark

Re: [PATCH] Don't use __BEGIN_DECLS macros from glibc.

[Mark Wielaard]

[-- Attachment #1: Type: text/plain, Size: 374 bytes --]

Hi Érico,

On Mon, 2020-10-26 at 23:24 +0100, Mark Wielaard wrote:
> Please just suggest a patch upstream to libc-alpha@sourceware.org.
> We'll pick it up when they decide to accept it. Note that it is also a
> public glibc header installed as /usr/include/elf.h.

I saw your patch was accepted upstream, so I synced it and pushed the
attached.

Thanks,

Mark

[-- Attachment #2: 0001-libelf-Sync-elf.h-from-glibc.patch --]
[-- Type: text/x-patch, Size: 1118 bytes --]

From 56f64c94651f4840e890c1963f9d6f6a4123abde Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mark@klomp.org>
Date: Wed, 28 Oct 2020 12:36:57 +0100
Subject: [PATCH] libelf: Sync elf.h from glibc.

Makes elf.h standalone and removes __BEGIN_DECLS/__END_DECLS macros.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---
 libelf/ChangeLog | 4 ++++
 libelf/elf.h     | 6 ------
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/libelf/ChangeLog b/libelf/ChangeLog
index a3f15883..b15508f2 100644
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -1,3 +1,7 @@
+2020-10-28  Mark Wielaard  <mark@klomp.org>
+
+	* elf.h: Update from glibc.
+
 2020-08-28  Mark Wielaard  <mark@klomp.org>
 
 	* elf.h: Update from glibc.
diff --git a/libelf/elf.h b/libelf/elf.h
index ff9f1dad..6439c1a4 100644
--- a/libelf/elf.h
+++ b/libelf/elf.h
@@ -19,10 +19,6 @@
 #ifndef _ELF_H
 #define	_ELF_H 1
 
-#include <features.h>
-
-__BEGIN_DECLS
-
 /* Standard ELF types.  */
 
 #include <stdint.h>
@@ -4105,6 +4101,4 @@ enum
 #define R_ARC_TLS_LE_S9		0x4a
 #define R_ARC_TLS_LE_32		0x4b
 
-__END_DECLS
-
 #endif	/* elf.h */
-- 
2.18.4