[OE-core] [PATCH] uclibc: Fix build with gcc5

[Khem Raj]

On Wed, Oct 14, 2015 at 6:01 PM, Andre McCurdy <armccurdy at gmail.com> wrote:
> On Wed, Oct 14, 2015 at 5:44 PM, Khem Raj <raj.khem at gmail.com> wrote:
>> An agressive optimization in gcc5 meant that we get linking errors
>> with uclibc build, this patch fixes the issue by letting gcc know
>> that these funcitons are used.
>
> Just for reference, the same fix has been in uclibc-ng since June:
>
>   http://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/commit/?id=96807d27a3ea01f427b6b98618ca87e9c1c00683
>

ah nice.

> It looks like uclibc-ng is really becoming the new upstream for uclibc.

yeah they should submit the patches to uclibc upstream and take more
active role.

>
>
>> Change-Id: I8ecf3999a0855b3bbf4bc2df576be5351f9be5b0
>> Signed-off-by: Khem Raj <raj.khem at gmail.com>
>> ---
>>  meta/recipes-core/uclibc/uclibc-git.inc            |  1 +
>>  ...zes-away-the-write-only-static-functions-.patch | 51 ++++++++++++++++++++++
>>  2 files changed, 52 insertions(+)
>>  create mode 100644 meta/recipes-core/uclibc/uclibc-git/0001-gcc5-optimizes-away-the-write-only-static-functions-.patch
>>
>> diff --git a/meta/recipes-core/uclibc/uclibc-git.inc b/meta/recipes-core/uclibc/uclibc-git.inc
>> index 14a577f..9e3d644 100644
>> --- a/meta/recipes-core/uclibc/uclibc-git.inc
>> +++ b/meta/recipes-core/uclibc/uclibc-git.inc
>> @@ -16,5 +16,6 @@ SRC_URI = "git://uclibc.org/uClibc.git;branch=master \
>>          file://0005-Always-use-O2-for-compiling-fork.c.patch \
>>          file://0006-ldso-limited-support-for-ORIGIN-in-rpath.patch \
>>          file://0007-nptl-atfork-Hide-pthread_atfork-in-shared-versions.patch \
>> +        file://0001-gcc5-optimizes-away-the-write-only-static-functions-.patch \
>>  "
>>  S = "${WORKDIR}/git"
>> diff --git a/meta/recipes-core/uclibc/uclibc-git/0001-gcc5-optimizes-away-the-write-only-static-functions-.patch b/meta/recipes-core/uclibc/uclibc-git/0001-gcc5-optimizes-away-the-write-only-static-functions-.patch
>> new file mode 100644
>> index 0000000..e622f87
>> --- /dev/null
>> +++ b/meta/recipes-core/uclibc/uclibc-git/0001-gcc5-optimizes-away-the-write-only-static-functions-.patch
>> @@ -0,0 +1,51 @@
>> +From 2659fb25d32f4b29c1c96aa5730fe40e19d53ab0 Mon Sep 17 00:00:00 2001
>> +From: Khem Raj <raj.khem at gmail.com>
>> +Date: Wed, 14 Oct 2015 17:38:37 -0700
>> +Subject: [PATCH] gcc5 optimizes away the write only static functions and we
>> + end up with
>> +
>> +  librt/librt_so.a(rt-unwind-resume.oS): In function `_Unwind_Resume':
>> +  rt-unwind-resume.c:(.text+0x3c): undefined reference to `libgcc_s_resume'
>> +  collect2: error: ld returned 1 exit status
>> +  make[2]: *** [lib/librt.so] Error 1
>> +
>> +marking these functions explicitly used with __attribute_used__ avoids
>> +that optimization.
>> +
>> +Signed-off-by: Khem Raj <raj.khem at gmail.com>
>> +---
>> +Upstream-Status: Pending
>> +
>> + libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-forcedunwind.c | 2 +-
>> + libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-resume.c       | 2 +-
>> + 2 files changed, 2 insertions(+), 2 deletions(-)
>> +
>> +diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-forcedunwind.c b/libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-forcedunwind.c
>> +index f4d6f41..0c2edd7 100644
>> +--- a/libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-forcedunwind.c
>> ++++ b/libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-forcedunwind.c
>> +@@ -27,7 +27,7 @@
>> + #define __libc_fatal(x)         {/*write(STDERR_FILENO, x, strlen(x));*/ abort();}
>> +
>> + static void *libgcc_s_handle;
>> +-static void (*libgcc_s_resume) (struct _Unwind_Exception *exc);
>> ++static void (*libgcc_s_resume) (struct _Unwind_Exception *exc) __attribute_used__;
>> + static _Unwind_Reason_Code (*libgcc_s_personality)
>> +   (_Unwind_State, struct _Unwind_Exception *, struct _Unwind_Context *);
>> + static _Unwind_Reason_Code (*libgcc_s_forcedunwind)
>> +diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-resume.c b/libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-resume.c
>> +index f9a4ffb..f0c3047 100644
>> +--- a/libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-resume.c
>> ++++ b/libpthread/nptl/sysdeps/unix/sysv/linux/arm/unwind-resume.c
>> +@@ -25,7 +25,7 @@
>> + #define __libc_dlclose          dlclose
>> + #define __libc_fatal(x)         {/*write(STDERR_FILENO, x, strlen(x));*/ abort();}
>> +
>> +-static void (*libgcc_s_resume) (struct _Unwind_Exception *exc);
>> ++static void (*libgcc_s_resume) (struct _Unwind_Exception *exc) __attribute_used__;
>> + static _Unwind_Reason_Code (*libgcc_s_personality)
>> +   (_Unwind_State, struct _Unwind_Exception *, struct _Unwind_Context *);
>> +
>> +--
>> +2.6.1
>> +
>> --
>> 2.6.1
>>
>> --
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