Open pchome opened 4 years ago
Ok, I patched sys-devel/gcc-9.2.0-r3
, sys-cluster/glusterfs-6.5
for testing and at least it compiles with -flto enabled.
Patch for sys-cluster/glusterfs-6.5:
--- a/api/src/glfs-internal.h
+++ b/api/src/glfs-internal.h
@@ -81,16 +81,16 @@
#define GFAPI_PRIVATE(sym, ver) /**/
#endif
#define GFAPI_SYMVER_PUBLIC_DEFAULT(fn, ver) \
- asm(".symver pub_" STR(fn) ", " STR(fn) "@@GFAPI_" STR(ver))
+ extern __typeof (pub_##fn) pub_##fn __attribute__((symver (STR(fn) "@@GFAPI_" STR(ver))))
#define GFAPI_SYMVER_PRIVATE_DEFAULT(fn, ver) \
- asm(".symver priv_" STR(fn) ", " STR(fn) "@@GFAPI_PRIVATE_" STR(ver))
+ extern __typeof (priv_##fn) priv_##fn __attribute__((symver (STR(fn) "@@GFAPI_PRIVATE_" STR(ver))))
#define GFAPI_SYMVER_PUBLIC(fn1, fn2, ver) \
- asm(".symver pub_" STR(fn1) ", " STR(fn2) "@GFAPI_" STR(ver))
+ extern __typeof (pub_##fn1) pub_##fn1 __attribute__((symver (STR(fn2) "@GFAPI_" STR(ver))))
#define GFAPI_SYMVER_PRIVATE(fn1, fn2, ver) \
- asm(".symver priv_" STR(fn1) ", " STR(fn2) "@GFAPI_PRIVATE_" STR(ver))
+ extern __typeof (priv_##fn1) priv_##fn1 __attribute__((symver (STR(fn2) "@GFAPI_PRIVATE_" STR(ver))))
#define STR(str) #str
#else
#ifndef GFAPI_PUBLIC
Found an suspect in my overrides: media-libs/alsa-lib-1.2.1.2
--- a/include/alsa-symbols.h
+++ b/include/alsa-symbols.h
@@ -30,9 +30,9 @@
#define INTERNAL(Name) INTERNAL_CONCAT2_2(__, Name)
#define symbol_version(real, name, version) \
- __asm__ (".symver " ASM_NAME(#real) "," ASM_NAME(#name) "@" #version)
+ extern __typeof (real) real __attribute__((symver (#name "@" #version)))
#define default_symbol_version(real, name, version) \
- __asm__ (".symver " ASM_NAME(#real) "," ASM_NAME(#name) "@@" #version)
+ extern __typeof (real) real __attribute__((symver (#name "@@" #version)))
#define EXPORT_SYMBOL __attribute__((visibility("default"),externally_visible))
Compiled fine with -flto enabled. Looks like everything works as before so far.
I guess we should kindly ask Gentoo™ to backport those GCC patches, so we will be able to play w/ symver more freely. Anyone with account on bugs.gentoo.org ?
Do we know when gcc-10 will be released? If it's not too long (their release timeline if they've stuck to it seems to suggest it won't be much longer), rather than backporting patches it could be more beneficial to import a newer snapshot of gcc to this overlay for testing.
Near 2020-05 according to release timeline? Then 10.1 will be masked for a while in portage.
My attempt to port them for gcc-9.2.0:
0001-gcc-symver-attribute.patch.gz
0002-gcc-symver-attribute-lto-binutils-workarounds.patch.gz
Unpack into /etc/portage/patches/sys-devel/gcc-9.2.0/
. Use at your own risk.
@pchome, I'm not sure that I am adequate with this track record: https://bugs.gentoo.org/buglist.cgi?bug_status=UNCONFIRMED&bug_status=CONFIRMED&bug_status=IN_PROGRESS&bug_status=RESOLVED&bug_status=VERIFIED&email1=halosyv&emailreporter1=1&emailtype1=substring&f1=reporter&f2=bug_status&list_id=4429324&o1=anywordssubstr&o2=anywordssubstr&query_format=advanced&resolution=---&resolution=FIXED&resolution=INVALID&resolution=WONTFIX&resolution=LATER&resolution=REMIND&resolution=DUPLICATE&resolution=WORKSFORME&resolution=CANTFIX&resolution=NEEDINFO&resolution=TEST-REQUEST&resolution=UPSTREAM&resolution=OBSOLETE&v1=halosyv
Also, I believe that Shane has a Bugzilla account as well.
We should really look into this for when GCC 10 comes around. It could knock off a chunk of overrides
Hm... Are there any GCC 10 live ebuilds in the Gentoo tree? If so, how smart would it be to switch to the compiler on a day-to-day system?
@elsandosgrande
Un-keyword sys-devel/gcc:10
, use eselect gcc set
only on packages you want to test. I see no problem.
@pchome So...
sandy@sandys-pavilion:~$ equery meta sys-devel/gcc
* sys-devel/gcc [gentoo]
Maintainer: toolchain@gentoo.org (Gentoo Toolchain Project)
Upstream: Remote-ID: cpe:/a:gnu:gcc ID: cpe
Remote-ID: dgcc ID: sourceforge
Homepage: https://gcc.gnu.org/
Location: /usr/portage/sys-devel/gcc
Keywords: 3.3.6-r5:3.3.6: ~amd64 ~x86
Keywords: 3.4.6-r5:3.4.6: ~alpha ~amd64 ~arm ~ia64 ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86 -*
Keywords: 4.0.4-r3:4.0.4:
Keywords: 4.1.2-r2:4.1.2: ~alpha ~amd64 ~arm ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86 -*
Keywords: 4.2.4-r4:4.2.4: ~alpha ~amd64 ~arm ~hppa ~ia64 ~m68k ~ppc ~ppc64 ~sparc ~x86
Keywords: 4.3.6-r4:4.3.6: -hppa ~alpha ~amd64 ~arm ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 4.4.7-r3:4.4.7: ~alpha ~amd64 ~arm ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 4.5.4-r3:4.5.4: ~alpha ~amd64 ~arm ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 4.6.4-r3:4.6.4: ~alpha ~amd64 ~arm ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 4.7.4-r3:4.7.4: ~alpha ~amd64 ~arm ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 4.8.5-r3:4.8.5: ~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 4.9.4-r1:4.9.4: ~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 5.5.0:5.5.0: ~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 6.5.0-r1:6.5.0: alpha amd64 arm arm64 hppa ia64 m68k ppc ppc64 s390 sh sparc x86 ~mips
Keywords: 7.4.0-r2:7.4.0: alpha amd64 arm arm64 hppa ia64 m68k ppc ppc64 s390 sh sparc x86 ~mips ~ppc-macos
Keywords: 7.5.0:7.5.0: ~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc-macos ~ppc64 ~s390 ~sh ~sparc ~x86
Keywords: 8.3.0-r1:8.3.0: alpha amd64 arm arm64 hppa ia64 m68k ppc ppc64 s390 sh sparc x86
Keywords: 8.3.0-r3:8.3.0: ~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sh ~sparc ~x86
Keywords: 9.2.0-r2:9.2.0: alpha amd64 arm arm64 hppa ia64 ppc ppc64 s390 sparc x86
Keywords: 9.2.0-r3:9.2.0: ~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sh ~sparc ~x86
Keywords: 10.0.0_pre9999:10:
License: GPL-3+ LGPL-3+ || ( GPL-3+ libgcc libstdc++ gcc-runtime-library-exception-3.1 ) FDL-1.3+
sandy@sandys-pavilion:~$ emerge --pretend =sys-devel/gcc:10
!!! '=sys-devel/gcc:10' is not a valid package atom.
!!! Please check ebuild(5) for full details.
I see no keywords for GCC 10...
I mean echo 'sys-devel/gcc:10 **' >> /etc/portage/package.accept_keywords
https://wiki.gentoo.org/wiki//etc/portage/package.accept_keywords
Also use emerge --pretend sys-devel/gcc:10
, w/o = ,
or emerge --pretend =sys-devel/gcc-10.0.0_pre9999
Since this is an unstable package you also have to promise not to bug the Gentoo toolchain maintainers (do not file bugs on bugs.gentoo.org):
I_PROMISE_TO_SUPPLY_PATCHES_WITH_BUGS=1
(that can also be a folder in which case use something like /etc/portage/package.env/gcc
)
sys-devel/gcc:10 i-promise-to-supply-patches-with-bugs
I wouldn't use this on your host system, maybe in a chroot though.
BTW, ... https://gcc.gnu.org/onlinedocs/gcc-10.2.0/gcc/Common-Function-Attributes.html
EDIT: a live example how to use this:
$ grep flto /var/db/pkg/*/*/*.ebuild
...
/var/db/pkg/sys-apps/attr-2.4.48-r5/attr-2.4.48-r5.ebuild: # Remove -flto* from flags as this breaks binaries (bug #644048)
/var/db/pkg/sys-apps/attr-2.4.48-r5/attr-2.4.48-r5.ebuild: filter-flags -flto*
...
There is a patch and it compiles with LTO. It has some interesting parts:
Add
__attribute__((no_reorder))
to the wrapper functions to avoid problems during LTO partitioning, since function definitions and their corresponding .symver directives must be emitted to the same partition to work correctly.
-int libattr_lsetxattr(const char *path, const char *name,
- void *value, size_t size, int flags)
+__attribute__((no_reorder))
+int lsetxattr(const char *path, const char *name,
+ const void *value, size_t size, int flags)
{
return syscall(__NR_lsetxattr, path, name, value, size, flags);
}
+__asm__(".symver lsetxattr, lsetxattr@ATTR_1.0");
The GCC 10 specific changes could look like this:
+__attribute__((__symver__ ("lsetxattr@ATTR_1.0")))
int libattr_lsetxattr(const char *path, const char *name,
const void *value, size_t size, int flags)
Which compiles and passes symbol test too.
It looks like future versions of GCC (>=10.0 ?) will introduce
__symver__
attribute as possible replacement for theasm (".symver foo_v1, foo@VERS_1")
code. Which will likely help some packages to compile with -flto (#458 ?).Description
Note: I manually converted formatting to MD, so there might be errors, especially with \@
symver ("name2@nodename")
On ELF targets this attribute creates a symbol version. The name2 part of the parameter is the actual name of the symbol by which it will be externally referenced. The
nodename
portion should be the name of a node specified in the version script supplied to the linker when building a shared library. Versioned symbol must be defined and must be exported with default visibility.Will produce a
.symver foo_v1, foo@VERS_1
directive in the assembler output.It's an error to define multiple version of a given symbol. In such case an alias can be used.
This example creates an alias of
foo_v1
with symbol namesymver_foo_v1
which will be versionVERS_2
offoo
.Finally if the parameter is
"name2@@nodename"
then in addition to creating a symbol version (as if"name2@nodename"
was used) the version will be also used to resolve name2 by the linker.Discussions
https://gcc.gnu.org/ml/gcc-patches/2019-11/threads.html#01334 https://gcc.gnu.org/ml/gcc-patches/2019-12/threads.html#00032
https://gcc.gnu.org/ml/gcc-patches/2019-12/threads.html#01162
Patches
https://gcc.gnu.org/ml/gcc-patches/2019-11/msg02712.html - symver attribute support https://gcc.gnu.org/ml/gcc-patches/2019-12/msg01363.html - some binutils workarounds
Possible conversion
before
after
https://gcc.gnu.org/ml/gcc-patches/2019-12/msg00040.html