CPython: WiP patches needed for cross compilation

patches/python-3.9.2/024-musl-find_library.patch

@@ -0,0 +1,74 @@
+https://bugs.python.org/issue21622
+
+Based on the patch from Alpine Linux
+https://git.alpinelinux.org/aports/tree/main/python2/musl-find_library.patch
+
+--- a/Lib/ctypes/util.py
++++ b/Lib/ctypes/util.py
+@@ -92,6 +92,8 @@ elif sys.platform.startswith("aix"):
+ elif os.name == "posix":
+     # Andreas Degert's find functions, using gcc, /sbin/ldconfig, objdump
+     import re, tempfile
++    from glob import glob
++    musl_ldso = glob('/lib/ld-musl-*.so.1')
+
+     def _is_elf(filename):
+         "Return True if the given file is an ELF file"
+@@ -265,6 +267,57 @@ elif os.name == "posix":
+         def find_library(name, is64 = False):
+             return _get_soname(_findLib_crle(name, is64) or _findLib_gcc(name))
+
++    elif musl_ldso and os.path.isfile(musl_ldso[0]):
++
++        def _is_elf(filepath):
++            try:
++                with open(filepath, 'rb') as fh:
++                    return fh.read(4) == b'\x7fELF'
++            except:
++                return False
++
++        def find_library(name):
++            # absolute name?
++            if os.path.isabs(name):
++                if _is_elf(name):
++                    return name
++                else:
++                    return None
++
++            # special case for unified standard libs
++            stdlibs = ['libcrypt.so', 'libdl.so', 'libm.so', 'libpthread.so', 'libresolv.so', 'librt.so', 'libutil.so', 'libxnet.so']
++            if name in stdlibs:
++                name = 'libc.so'
++            elif ('lib' + name + '.so') in stdlibs:
++                name = 'c'
++
++            paths = []
++            # read path list from /etc/ld-musl-$(ARCH).path
++            path_list = musl_ldso[0].replace('/lib/', '/etc/').replace('.so.1', '.path')
++            try:
++                with open(path_list, 'r') as fh:
++                    paths = [path for line in fh for path in line.rstrip('\n').split(':') if path]
++            except:
++                paths = []
++            # default path list if /etc/ld-musl-$(ARCH).path is empty or does not exist
++            if not paths:
++                paths = ['/lib', '/usr/local/lib', '/usr/lib']
++
++            # prepend paths from LD_LIBRARY_PATH
++            if 'LD_LIBRARY_PATH' in os.environ:
++                paths = os.environ['LD_LIBRARY_PATH'].split(':') + paths
++
++            for d in paths:
++                f = os.path.join(d, name)
++                if _is_elf(f):
++                    return os.path.basename(f)
++
++                prefix = os.path.join(d, 'lib'+name)
++                for suffix in ['.so', '.so.*']:
++                    for f in glob('{0}{1}'.format(prefix, suffix)):
++                        if _is_elf(f):
++                            return os.path.basename(f)
++
+     else:
+
+         def _findSoname_ldconfig(name):

patches/python-3.9.2/030-bpo-43112-detect-musl-as-a-separate-SOABI-GH-24502.patch

@@ -0,0 +1,75 @@
+From 3f79de7b8411c76a1fcd1ca850ea62500be7a881 Mon Sep 17 00:00:00 2001
+From: Natanael Copa <ncopa@alpinelinux.org>
+Date: Sat, 29 Jan 2022 00:02:54 +0100
+Subject: [PATCH 1/2] bpo-43112: detect musl as a separate SOABI (GH-24502)
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+musl libc and gnu libc are not ABI compatible so we need set different
+SOABI for musl and not simply assume that all linux is linux-gnu.
+
+Replace linux-gnu with the detected os for the build from config.guess
+for linux-musl*.
+
+(cherry picked from commit 1f036ede59e2c4befc07714cf76603c591d5c972)
+Signed-off-by: Šimon Bořek <simon.borek@nic.cz>
+---
+ Lib/test/test_sysconfig.py                                | 8 ++++----
+ .../next/Build/2021-02-10-17-54-04.bpo-43112.H5Lat6.rst   | 1 +
+ configure                                                 | 5 +++++
+ configure.ac                                              | 5 +++++
+ 4 files changed, 15 insertions(+), 4 deletions(-)
+ create mode 100644 Misc/NEWS.d/next/Build/2021-02-10-17-54-04.bpo-43112.H5Lat6.rst
+
+--- a/Lib/test/test_sysconfig.py
++++ b/Lib/test/test_sysconfig.py
+@@ -425,11 +425,11 @@ class TestSysConfig(unittest.TestCase):
+             self.assertTrue('linux' in suffix, suffix)
+         if re.match('(i[3-6]86|x86_64)$', machine):
+             if ctypes.sizeof(ctypes.c_char_p()) == 4:
+-                self.assertTrue(suffix.endswith('i386-linux-gnu.so') or
+-                                suffix.endswith('x86_64-linux-gnux32.so'),
+-                                suffix)
++                expected_suffixes = 'i386-linux-gnu.so', 'x86_64-linux-gnux32.so', 'i386-linux-musl.so'
+             else: # 8 byte pointer size
+-                self.assertTrue(suffix.endswith('x86_64-linux-gnu.so'), suffix)
++                expected_suffixes = 'x86_64-linux-gnu.so', 'x86_64-linux-musl.so'
++            self.assertTrue(suffix.endswith(expected_suffixes),
++                            f'unexpected suffix {suffix!r}')
+
+     @unittest.skipUnless(sys.platform == 'darwin', 'OS X-specific test')
+     def test_osx_ext_suffix(self):
+--- /dev/null
++++ b/Misc/NEWS.d/next/Build/2021-02-10-17-54-04.bpo-43112.H5Lat6.rst
+@@ -0,0 +1 @@
++Detect musl libc as a separate SOABI (tagged as ``linux-musl``).
+\ No newline at end of file
+--- a/configure
++++ b/configure
+@@ -5376,6 +5376,11 @@ EOF
+
+ if $CPP $CPPFLAGS conftest.c >conftest.out 2>/dev/null; then
+   PLATFORM_TRIPLET=`grep -v '^#' conftest.out | grep -v '^ *$' | tr -d ' 	'`
++  case "$build_os" in
++  linux-musl*)
++    PLATFORM_TRIPLET=`echo "$PLATFORM_TRIPLET" | sed 's/linux-gnu/linux-musl/'`
++    ;;
++  esac
+   { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PLATFORM_TRIPLET" >&5
+ $as_echo "$PLATFORM_TRIPLET" >&6; }
+ else
+--- a/configure.ac
++++ b/configure.ac
+@@ -866,6 +866,11 @@ EOF
+
+ if $CPP $CPPFLAGS conftest.c >conftest.out 2>/dev/null; then
+   PLATFORM_TRIPLET=`grep -v '^#' conftest.out | grep -v '^ *$' | tr -d ' 	'`
++  case "$build_os" in
++  linux-musl*)
++    PLATFORM_TRIPLET=`echo "$PLATFORM_TRIPLET" | sed 's/linux-gnu/linux-musl/'`
++    ;;
++  esac
+   AC_MSG_RESULT([$PLATFORM_TRIPLET])
+ else
+   AC_MSG_RESULT([none])