Re: [Buildroot] [PATCH v3] package/attr: fix build failure on Microblaze architecture

["Yann E. MORIN" <yann.morin.1998@free.fr>]

giulio, all,

On 2024-02-18 09:20 +0100, Giulio Benetti spake thusly:
> On Microblaze architecture __has_attribute(__symver__) support is broken
> and always return true even if symver is not supported so let's add an
> upstream patch to detect if symver is supported during autoreconf. Let's
> also add ATTR_AUTORECONF = YES to let patch to affect building.
> 
> Fixes:
> http://autobuild.buildroot.org/results/29c76e02becedf922bd7dc0533338c078bf77d2a
> 
> Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>

Applied to master, thanks.

Regards,
Yann E. MORIN.

> ---
> V1->V2:
> * written commit log as suggested by Thomas(there was no commit log at all
>   since this patch has been pointed during Buildroot Dev Days in IRC to me)
> * re-sent local patch to the correct maililng list and updated Upstream:
>   URL
> V2->V3:
> * since patch has been upstreamed after a little rework, use it and point
>   upstream commit URL
> ---
>  ...dd-detection-of-symver-gcc-attribute.patch | 75 +++++++++++++++++++
>  package/attr/attr.mk                          |  3 +
>  2 files changed, 78 insertions(+)
>  create mode 100644 package/attr/0002-configure.ac-add-detection-of-symver-gcc-attribute.patch
> 
> diff --git a/package/attr/0002-configure.ac-add-detection-of-symver-gcc-attribute.patch b/package/attr/0002-configure.ac-add-detection-of-symver-gcc-attribute.patch
> new file mode 100644
> index 0000000000..ee029e9735
> --- /dev/null
> +++ b/package/attr/0002-configure.ac-add-detection-of-symver-gcc-attribute.patch
> @@ -0,0 +1,75 @@
> +From 365426c28f8bf73d34d77cc06b7d5ffeae17f13a Mon Sep 17 00:00:00 2001
> +From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> +Date: Tue, 6 Feb 2024 15:33:15 +0100
> +Subject: [PATCH] configure.ac: add detection of symver gcc attribute
> +
> +On non-ELF platforms, such as microblaze, builds will fail when trying
> +to add symver information because  __attribute__((symver ..)) is not
> +supported even though __has_attribute(__symver__) returns true.
> +
> +Support for symver needs to be detected via a compile test since
> +__has_attribute can report false positives [0].
> +
> +Add a configure compile check for __attribute__((symver ..)) to ensure
> +it is supported and define a variable to advertise support.
> +
> +[0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101766#c1
> +
> +Upstream: https://git.savannah.nongnu.org/cgit/attr.git/commit/?id=943c776089dbb24ebbfb7432ba9841f1845bf95a
> +
> +Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> +[Giulio: rework local patch for #if nesting]
> +Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
> +---
> + configure.ac       | 15 +++++++++++++++
> + libattr/syscalls.c |  8 ++++----
> + 2 files changed, 19 insertions(+), 4 deletions(-)
> +
> +diff --git a/configure.ac b/configure.ac
> +index 7e362e9..98477b5 100644
> +--- a/configure.ac
> ++++ b/configure.ac
> +@@ -57,6 +57,21 @@ AS_CASE([$host_os],
> + 	[linux*], [os_linux=yes])
> + AM_CONDITIONAL([OS_LINUX], [test "x$os_linux" = "xyes"])
> + 
> ++AC_CACHE_CHECK(whether __attribute__((__symver__())) is supported,
> ++	gcc_cv_symver_attribute,
> ++	[cat > conftest.c <<EOF
> ++void foo (void) {}
> ++__typeof(foo) foo __attribute__ ((__symver__("foo@foo")));
> ++EOF
> ++	gcc_cv_symver_attribute=no
> ++	if ${CC-cc} -Werror -S conftest.c -o conftest.s >/dev/null 2>&1; then \
> ++	    gcc_cv_symver_attribute=yes
> ++	fi
> ++	rm -f conftest.[cs]
> ++])
> ++AS_IF([test $gcc_cv_symver_attribute = yes],
> ++      [AC_DEFINE(HAVE_SYMVER_ATTRIBUTE, [], [GCC supports symver attribute])])
> ++
> + AC_CONFIG_COMMANDS([include/attr],
> + 	[dnl
> + 	rm -rf include/attr
> +diff --git a/libattr/syscalls.c b/libattr/syscalls.c
> +index 907560a..7ee6d39 100644
> +--- a/libattr/syscalls.c
> ++++ b/libattr/syscalls.c
> +@@ -31,10 +31,10 @@
> +  * prefer symver attribute if available (since gcc 10),
> +  * fall back to traditional .symver asm directive otherwise.
> +  */
> +-#ifdef __has_attribute
> +-# if __has_attribute(__symver__)
> +-#  define SYMVER(cn, vn) __typeof(cn) cn __attribute__((__symver__(vn)))
> +-# elif __has_attribute(__no_reorder__)
> ++#if defined(HAVE_SYMVER_ATTRIBUTE)
> ++# define SYMVER(cn, vn) __typeof(cn) cn __attribute__((__symver__(vn)))
> ++#elif defined(__has_attribute)
> ++# if __has_attribute(__no_reorder__)
> +    /*
> +     * Avoid wrong partitioning with older gcc and LTO. May not work reliably
> +     * with all versions; use -flto-partition=none if you encounter problems.
> +-- 
> +2.34.1
> +
> diff --git a/package/attr/attr.mk b/package/attr/attr.mk
> index d1397921ff..1d24144f46 100644
> --- a/package/attr/attr.mk
> +++ b/package/attr/attr.mk
> @@ -11,6 +11,9 @@ ATTR_LICENSE = GPL-2.0+ (programs), LGPL-2.1+ (libraries)
>  ATTR_LICENSE_FILES = doc/COPYING doc/COPYING.LGPL
>  ATTR_CPE_ID_VALID = YES
>  
> +# Flag added for patch dealing with symver in configure.ac
> +ATTR_AUTORECONF = YES
> +
>  ATTR_INSTALL_STAGING = YES
>  
>  ATTR_CONF_OPTS = --disable-nls
> -- 
> 2.34.1
> 
> _______________________________________________
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> buildroot@buildroot.org
> https://lists.buildroot.org/mailman/listinfo/buildroot

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