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, 210 deletions

diff --git a/package/glibc/0005-Provide-a-C-version-of-iszero-that-does-not-use-__MA.patch b/package/glibc/0005-Provide-a-C-version-of-iszero-that-does-not-use-__MA.patch
deleted file mode 100644
index e12c8438fd..0000000000
--- a/package/glibc/0005-Provide-a-C-version-of-iszero-that-does-not-use-__MA.patch
+++ /dev/null
@@ -1,210 +0,0 @@
-From 45970aa26d1af87b016ef95b4b35c566aeb6e841 Mon Sep 17 00:00:00 2001
-From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
-Date: Tue, 22 Aug 2017 16:34:42 -0300
-Subject: [PATCH] Provide a C++ version of iszero that does not use __MATH_TG
- (bug 21930)
-
-When signaling nans are enabled (with -fsignaling-nans), the C++ version
-of iszero uses the fpclassify macro, which is defined with __MATH_TG.
-However, when support for float128 is available, __MATH_TG uses the
-builtin __builtin_types_compatible_p, which is only available in C mode.
-
-This patch refactors the C++ version of iszero so that it uses function
-overloading to select between the floating-point types, instead of
-relying on fpclassify and __MATH_TG.
-
-Tested for powerpc64le, s390x, x86_64, and with build-many-glibcs.py.
-
-	[BZ #21930]
-	* math/math.h [defined __cplusplus && defined __SUPPORT_SNAN__]
-	(iszero): New C++ implementation that does not use
-	fpclassify/__MATH_TG/__builtin_types_compatible_p, when
-	signaling nans are enabled, since __builtin_types_compatible_p
-	is a C-only feature.
-	* math/test-math-iszero.cc: When __HAVE_DISTINCT_FLOAT128 is
-	defined, include ieee754_float128.h for access to the union and
-	member ieee854_float128.ieee.
-	[__HAVE_DISTINCT_FLOAT128] (do_test): Call check_float128.
-	[__HAVE_DISTINCT_FLOAT128] (check_float128): New function.
-	* sysdeps/powerpc/powerpc64le/Makefile [subdir == math]
-	(CXXFLAGS-test-math-iszero.cc): Add -mfloat128 to the build
-	options of test-math-zero on powerpc64le.
-
-(cherry picked from commit 42496114ec0eb7d6d039d05d4262e109951c600c)
-[Romain rebase on glibc 2.26]
-Signed-off-by: Romain Naour <romain.naour@gmail.com>
----
- math/math.h                          | 33 +++++++++++++--
- math/test-math-iszero.cc             | 79 ++++++++++++++++++++++++++++++++++++
- sysdeps/powerpc/powerpc64le/Makefile |  3 +-
- 3 files changed, 110 insertions(+), 5 deletions(-)
-
-diff --git a/math/math.h b/math/math.h
-index 60dfa31..7c0fc6d 100644
---- a/math/math.h
-+++ b/math/math.h
-@@ -513,15 +513,40 @@ inline int issignaling (_Float128 __val) { return __issignalingf128 (__val); }
- #  endif
- # else	/* __cplusplus */
- extern "C++" {
-+#  ifdef __SUPPORT_SNAN__
-+inline int
-+iszero (float __val)
-+{
-+  return __fpclassifyf (__val) == FP_ZERO;
-+}
-+inline int
-+iszero (double __val)
-+{
-+  return __fpclassify (__val) == FP_ZERO;
-+}
-+inline int
-+iszero (long double __val)
-+{
-+#   ifdef __NO_LONG_DOUBLE_MATH
-+  return __fpclassify (__val) == FP_ZERO;
-+#   else
-+  return __fpclassifyl (__val) == FP_ZERO;
-+#   endif
-+}
-+#   if __HAVE_DISTINCT_FLOAT128
-+inline int
-+iszero (_Float128 __val)
-+{
-+  return __fpclassifyf128 (__val) == FP_ZERO;
-+}
-+#   endif
-+#  else
- template <class __T> inline bool
- iszero (__T __val)
- {
--#  ifdef __SUPPORT_SNAN__
--  return fpclassify (__val) == FP_ZERO;
--#  else
-   return __val == 0;
--#  endif
- }
-+#  endif
- } /* extern C++ */
- # endif	/* __cplusplus */
- #endif /* Use IEC_60559_BFP_EXT.  */
-diff --git a/math/test-math-iszero.cc b/math/test-math-iszero.cc
-index 027e972..5c07261 100644
---- a/math/test-math-iszero.cc
-+++ b/math/test-math-iszero.cc
-@@ -22,6 +22,13 @@
- 
- #include <limits>
- 
-+/* Support for _Float128 in std::numeric_limits is limited.
-+   Include ieee754_float128.h and use the bitfields in the union
-+   ieee854_float128.ieee_nan to build corner-case inputs.  */
-+#if __HAVE_DISTINCT_FLOAT128
-+# include <ieee754_float128.h>
-+#endif
-+
- static bool errors;
- 
- static void
-@@ -72,12 +79,84 @@ check_type ()
-          std::numeric_limits<T>::has_denorm == std::denorm_absent);
- }
- 
-+#if __HAVE_DISTINCT_FLOAT128
-+static void
-+check_float128 ()
-+{
-+  ieee854_float128 q;
-+
-+  q.d = 0.0Q;
-+  CHECK (iszero (q.d), 1);
-+  q.d = -0.0Q;
-+  CHECK (iszero (q.d), 1);
-+  q.d = 1.0Q;
-+  CHECK (iszero (q.d), 0);
-+  q.d = -1.0Q;
-+  CHECK (iszero (q.d), 0);
-+
-+  /* Normal min.  */
-+  q.ieee.negative = 0;
-+  q.ieee.exponent = 0x0001;
-+  q.ieee.mantissa0 = 0x0000;
-+  q.ieee.mantissa1 = 0x00000000;
-+  q.ieee.mantissa2 = 0x00000000;
-+  q.ieee.mantissa3 = 0x00000000;
-+  CHECK (iszero (q.d), 0);
-+  q.ieee.negative = 1;
-+  CHECK (iszero (q.d), 0);
-+
-+  /* Normal max.  */
-+  q.ieee.negative = 0;
-+  q.ieee.exponent = 0x7FFE;
-+  q.ieee.mantissa0 = 0xFFFF;
-+  q.ieee.mantissa1 = 0xFFFFFFFF;
-+  q.ieee.mantissa2 = 0xFFFFFFFF;
-+  q.ieee.mantissa3 = 0xFFFFFFFF;
-+  CHECK (iszero (q.d), 0);
-+  q.ieee.negative = 1;
-+  CHECK (iszero (q.d), 0);
-+
-+  /* Infinity.  */
-+  q.ieee.negative = 0;
-+  q.ieee.exponent = 0x7FFF;
-+  q.ieee.mantissa0 = 0x0000;
-+  q.ieee.mantissa1 = 0x00000000;
-+  q.ieee.mantissa2 = 0x00000000;
-+  q.ieee.mantissa3 = 0x00000000;
-+  CHECK (iszero (q.d), 0);
-+
-+  /* Quiet NaN.  */
-+  q.ieee_nan.quiet_nan = 1;
-+  q.ieee_nan.mantissa0 = 0x0000;
-+  CHECK (iszero (q.d), 0);
-+
-+  /* Signaling NaN.  */
-+  q.ieee_nan.quiet_nan = 0;
-+  q.ieee_nan.mantissa0 = 0x4000;
-+  CHECK (iszero (q.d), 0);
-+
-+  /* Denormal min.  */
-+  q.ieee.negative = 0;
-+  q.ieee.exponent = 0x0000;
-+  q.ieee.mantissa0 = 0x0000;
-+  q.ieee.mantissa1 = 0x00000000;
-+  q.ieee.mantissa2 = 0x00000000;
-+  q.ieee.mantissa3 = 0x00000001;
-+  CHECK (iszero (q.d), 0);
-+  q.ieee.negative = 1;
-+  CHECK (iszero (q.d), 0);
-+}
-+#endif
-+
- static int
- do_test (void)
- {
-   check_type<float> ();
-   check_type<double> ();
-   check_type<long double> ();
-+#if __HAVE_DISTINCT_FLOAT128
-+  check_float128 ();
-+#endif
-   return errors;
- }
- 
-diff --git a/sysdeps/powerpc/powerpc64le/Makefile b/sysdeps/powerpc/powerpc64le/Makefile
-index 19adbfa..dea2290 100644
---- a/sysdeps/powerpc/powerpc64le/Makefile
-+++ b/sysdeps/powerpc/powerpc64le/Makefile
-@@ -17,7 +17,8 @@ $(foreach suf,$(all-object-suffixes),$(objpfx)test-float128%$(suf)): CFLAGS += -
- $(foreach suf,$(all-object-suffixes),$(objpfx)test-ifloat128%$(suf)): CFLAGS += -mfloat128
- CFLAGS-libm-test-support-float128.c += -mfloat128
- CFLAGS-test-math-issignaling.cc += -mfloat128
--$(objpfx)test-float128% $(objpfx)test-ifloat128%: \
-+CFLAGS-test-math-iszero.cc += -mfloat128
-+$(objpfx)test-float128% $(objpfx)test-ifloat128% $(objpfx)test-math-iszero: \
-   gnulib-tests += $(f128-loader-link)
- endif
- 
--- 
-2.9.5
-