package/botan: fix build with -latomic

Static build with toolchains needing -latomic (e.g sparc) is broken
since version 2.17.0 and
https://github.com/randombit/botan/commit/88af81b88976d9a1293280f68df597220ab42767

Fixes:
 - http://autobuild.buildroot.org/results/5c03ee53a34a3cdb409cffcda76e5cc2c723778b

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/botan/0001-Add--extra-libs-option-and-group-l-flags-from-LDFLAGS-to-the-end.patch

@@ -0,0 +1,75 @@
+From af63fe89228172e5a395f7e6491fae3bfa9da4b1 Mon Sep 17 00:00:00 2001
+From: Jack Lloyd <jack@randombit.net>
+Date: Mon, 15 Feb 2021 15:01:38 -0500
+Subject: [PATCH] Add --extra-libs option and group -l flags from LDFLAGS to
+ the end
+
+Ref #2622
+
+[Retrieved from:
+https://github.com/randombit/botan/commit/af63fe89228172e5a395f7e6491fae3bfa9da4b1]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ configure.py               | 14 ++++++++++++++
+ src/build-data/makefile.in |  2 +-
+ 2 files changed, 15 insertions(+), 1 deletion(-)
+
+diff --git a/configure.py b/configure.py
+index 73fc0271e9..865a6c8e62 100755
+--- a/configure.py
++++ b/configure.py
+@@ -333,6 +333,9 @@ def process_command_line(args): # pylint: disable=too-many-locals,too-many-state
+     target_group.add_option('--ldflags', metavar='FLAGS',
+                             help='set linker flags', default=None)
+ 
++    target_group.add_option('--extra-libs', metavar='LIBS',
++                            help='specify extra libraries to link against', default='')
++
+     target_group.add_option('--ar-command', dest='ar_command', metavar='AR', default=None,
+                             help='set path to static archive creator')
+ 
+@@ -2020,6 +2023,12 @@ def choose_cxx_exe():
+         else:
+             return '%s %s' % (options.compiler_cache, cxx)
+ 
++    def extra_libs(libs, cc):
++        if libs is None:
++            return ''
++
++        return ' '.join([(cc.add_lib_option % lib) for lib in libs.split(',')])
++
+     variables = {
+         'version_major':  Version.major(),
+         'version_minor':  Version.minor(),
+@@ -2149,6 +2158,7 @@ def choose_cxx_exe():
+         'cc_sysroot': sysroot_option(),
+         'cc_compile_flags': options.cxxflags or cc.cc_compile_flags(options),
+         'ldflags': options.ldflags or '',
++        'extra_libs': extra_libs(options.extra_libs, cc),
+         'cc_warning_flags': cc.cc_warning_flags(options),
+         'output_to_exe': cc.output_to_exe,
+         'cc_macro': cc.macro_name,
+@@ -3029,6 +3039,10 @@ def canonicalize_build_targets(options):
+     if options.build_fuzzers == 'libfuzzer' and options.fuzzer_lib is None:
+         options.fuzzer_lib = 'Fuzzer'
+ 
++    if options.ldflags is not None:
++        libs = [m.group(1) for m in re.finditer(r'-l([a-z0-9]+)', options.ldflags)]
++        options.extra_libs += ','.join(libs)
++
+ # Checks user options for consistency
+ # This method DOES NOT change options on behalf of the user but explains
+ # why the given configuration does not work.
+diff --git a/src/build-data/makefile.in b/src/build-data/makefile.in
+index 4692d00f71..82f6576650 100644
+--- a/src/build-data/makefile.in
++++ b/src/build-data/makefile.in
+@@ -20,7 +20,7 @@ LDFLAGS        = %{ldflags}
+ EXE_LINK_CMD   = %{exe_link_cmd}
+ 
+ LIB_LINKS_TO   = %{external_link_cmd} %{link_to}
+-EXE_LINKS_TO   = %{link_to_botan} $(LIB_LINKS_TO)
++EXE_LINKS_TO   = %{link_to_botan} $(LIB_LINKS_TO) %{extra_libs}
+ 
+ BUILD_FLAGS    = $(ABI_FLAGS) $(LANG_FLAGS) $(CXXFLAGS) $(WARN_FLAGS)
+ 

package/botan/botan.mk

@@ -18,14 +18,11 @@ BOTAN_CONF_OPTS = \
 	--os=linux \
 	--cc=gcc \
 	--cc-bin="$(TARGET_CXX)" \
-	--ldflags="$(BOTAN_LDFLAGS)" \
 	--prefix=/usr \
 	--without-documentation
 
-BOTAN_LDFLAGS = $(TARGET_LDFLAGS)
-
 ifeq ($(BR2_TOOLCHAIN_HAS_LIBATOMIC),y)
-BOTAN_LDFLAGS += -latomic
+BOTAN_CONF_OPTS += --extra-libs=atomic
 endif
 
 ifeq ($(BR2_SHARED_LIBS),y)