package/glibc: switch to using the maintenance branch

glibc upstream has ruled against doing regular point-releases, but they
do have a lot of interesting and important fixes for regressions and
security.

Backporting each patch, or cherry-picking individual patches is off
limits for us, so we just switch to using the currently-latest HEAD of
the maintenance branch instead.

The version number is obtained with:
    $ git describe --match 'glibc-*' --abbrev=40 origin/release/2.26/master

The alternative options were:
  - download the tarball from the git tree
    --> does not work; not an option
  - download the 2.26 tarball, and bundle the individual patches in
    Buildroot
    --> maintenance of patches is a burden; not an option
  - download the 2.26 tarball, maintain the list of patches to download from
    the git tree
    --> not an option for the same reason

So we end up just doing a git clone. The git tree is today about ten
times the size of the tarball, so a rough estimate makes it at about ten
times the download time.

Also upstream doesn't officially provide an https download location [1].
There is one but it's not reliable, sometimes the connection time out and
end-up with a corrupted git repo:

fatal: unable to access 'https://sourceware.org/git/glibc.git/': Failed to connect to sourceware.org port 443: Connection timed out

So switch to using a git mirror from github which is updated once a day [2].
This allow at the same time to clone the git repository faster.

Note: The glibc 2.26 patches are not kept for the arc toolchain since they
are fixing an issue with the new float128 support introduced in x86, x86_64
and powerpc64le.

[1] https://sourceware.org/git/?p=glibc.git;a=summary
[2] https://github.com/bminor/glibc.git

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Romain Naour <romain.naour@openwide.fr>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Evgeniy Didin <didin@synopsys.com>
CC: Alexey Brodkin <abrodkin@synopsys.com>
[Romain: bump 4b692dffb95ac4812b161eb6a16113d7e824982e]
Signed-off-by: Romain Naour <romain.naour@gmail.com>
[yann.morin.1998@free.fr: update comment to never decide on the mirror]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

1 files changed, 0 insertions, 56 deletions

diff --git a/package/glibc/0002-Do-not-use-generic-selection-in-C-mode.patch b/package/glibc/0002-Do-not-use-generic-selection-in-C-mode.patch
deleted file mode 100644
index 7321eebd6e..0000000000
--- a/package/glibc/0002-Do-not-use-generic-selection-in-C-mode.patch
+++ /dev/null
@@ -1,56 +0,0 @@
-From bb21afc362a3ecba07ab386a0bc4385e75fbd4b5 Mon Sep 17 00:00:00 2001
-From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
-Date: Mon, 14 Aug 2017 17:51:51 -0300
-Subject: [PATCH] Do not use generic selection in C++ mode
-
-The logic to protect the use of generic selection (_Generic) does not
-check for C or C++ mode, however, generic selection is a C-only
-feature.
-
-Tested for powerpc64le.
-
-	* misc/sys/cdefs.h (__HAVE_GENERIC_SELECTION): Define to 0, if
-	in C++ mode.
-
-(cherry picked from commit 6913ad65e00bb32417ad39c41d292b976171e27e)
-[Romain rebase on glibc 2.26]
-Signed-off-by: Romain Naour <romain.naour@gmail.com>
----
- misc/sys/cdefs.h | 19 ++++++++++---------
- 1 file changed, 10 insertions(+), 9 deletions(-)
-
-diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
-index 06523bf..0c80821 100644
---- a/misc/sys/cdefs.h
-+++ b/misc/sys/cdefs.h
-@@ -464,17 +464,18 @@
- # define __glibc_macro_warning(msg)
- #endif
- 
--/* Support for generic selection (ISO C11) is available in GCC since
--   version 4.9.  Previous versions do not provide generic selection,
--   even though they might set __STDC_VERSION__ to 201112L, when in
--   -std=c11 mode.  Thus, we must check for !defined __GNUC__ when
--   testing __STDC_VERSION__ for generic selection support.
-+/* Generic selection (ISO C11) is a C-only feature, available in GCC
-+   since version 4.9.  Previous versions do not provide generic
-+   selection, even though they might set __STDC_VERSION__ to 201112L,
-+   when in -std=c11 mode.  Thus, we must check for !defined __GNUC__
-+   when testing __STDC_VERSION__ for generic selection support.
-    On the other hand, Clang also defines __GNUC__, so a clang-specific
-    check is required to enable the use of generic selection.  */
--#if __GNUC_PREREQ (4, 9) \
--    || __glibc_clang_has_extension (c_generic_selections) \
--    || (!defined __GNUC__ && defined __STDC_VERSION__ \
--	&& __STDC_VERSION__ >= 201112L)
-+#if !defined __cplusplus \
-+    && (__GNUC_PREREQ (4, 9) \
-+	|| __glibc_clang_has_extension (c_generic_selections) \
-+	|| (!defined __GNUC__ && defined __STDC_VERSION__ \
-+	    && __STDC_VERSION__ >= 201112L))
- # define __HAVE_GENERIC_SELECTION 1
- #else
- # define __HAVE_GENERIC_SELECTION 0
--- 
-2.9.5
-