libucontext: Add recipe

Help musl based systems provide ucontext APIs, these APIs are used in
some common applications e.g. chromium browser

(From OE-Core rev: 51c329d2d3fbefd5483bb78f471f4c222ad061c1)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/conf/distro/include/maintainers.inc

@@ -386,6 +386,7 @@ RECIPE_MAINTAINER_pn-libtirpc = "Anuj Mittal <anuj.mittal@intel.com>"
 RECIPE_MAINTAINER_pn-libtool = "Robert Yang <liezhi.yang@windriver.com>"
 RECIPE_MAINTAINER_pn-libtool-cross = "Robert Yang <liezhi.yang@windriver.com>"
 RECIPE_MAINTAINER_pn-libtool-native = "Robert Yang <liezhi.yang@windriver.com>"
+RECIPE_MAINTAINER_pn-libucontext = "Khem Raj <raj.khem@gmail.com>"
 RECIPE_MAINTAINER_pn-libunistring = "Anuj Mittal <anuj.mittal@intel.com>"
 RECIPE_MAINTAINER_pn-libunwind = "Bruce Ashfield <bruce.ashfield@gmail.com>"
 RECIPE_MAINTAINER_pn-liburcu = "Alexander Kanavin <alex.kanavin@gmail.com>"

meta/recipes-core/musl/libucontext/0001-pass-LDFLAGS-to-link-step.patch

@@ -0,0 +1,31 @@
+From 12d45d250d08e96e889e38e77273c3ef73e6fc97 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Mon, 25 Nov 2019 15:07:35 -0800
+Subject: [PATCH] pass LDFLAGS to link step
+
+This helps to use OE specific linker flags and fixes
+
+do_package_qa: QA Issue: No GNU_HASH in the ELF binary
+
+Upstream-Status: Pending
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ Makefile | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/Makefile b/Makefile
+index 8a605fd..d1c9637 100644
+--- a/Makefile
++++ b/Makefile
+@@ -20,7 +20,7 @@ ${LIBUCONTEXT_STATIC_NAME}: ${LIBUCONTEXT_OBJ}
+ 
+ ${LIBUCONTEXT_NAME}: ${LIBUCONTEXT_OBJ}
+ 	$(CC) -o ${LIBUCONTEXT_NAME} -Wl,-soname,${LIBUCONTEXT_SONAME} \
+-		-shared ${LIBUCONTEXT_OBJ}
++		-shared ${LIBUCONTEXT_OBJ} ${LDFLAGS}
+ 
+ ${LIBUCONTEXT_SONAME}: ${LIBUCONTEXT_NAME}
+ 	ln -sf ${LIBUCONTEXT_NAME} ${LIBUCONTEXT_SONAME}
+-- 
+2.24.0
+

meta/recipes-core/musl/libucontext_git.bb

@@ -0,0 +1,62 @@
+# Copyright (C) 2019 Khem Raj <raj.khem@gmail.com>
+# Released under the MIT license (see COPYING.MIT for the terms)
+
+SUMMARY = "ucontext implementation featuring glibc-compatible ABI"
+HOMEPAGE = "https://github.com/kaniini/libucontext"
+LICENSE = "ISC"
+LIC_FILES_CHKSUM = "file://LICENSE;md5=864cc1445419406b7093e8e531c9515e"
+SECTION = "libs"
+DEPENDS = ""
+
+PV = "0.1.3+${SRCPV}"
+SRCREV = "e6b4d7516dae9b200e94fcfcb9ebc9331389655f"
+SRC_URI = "git://code.foxkit.us/adelie/libucontext.git;protocol=https \
+           file://0001-pass-LDFLAGS-to-link-step.patch \
+"
+
+S = "${WORKDIR}/git"
+
+COMPATIBLE_HOST = ".*-musl.*"
+
+valid_archs = "\
+i386 x86 \
+ppc powerpc powerpc64 ppc64  \
+arm aarch64 \
+s390 \
+"
+
+def map_kernel_arch(a, d):
+    import re
+
+    valid_archs = d.getVar('valid_archs').split()
+
+    if   re.match('(i.86|athlon)$', a):         return 'x86'
+    elif re.match('x86.64$', a):                return 'x86_64'
+    elif re.match('armeb$', a):                 return 'arm'
+    elif re.match('aarch64$', a):               return 'aarch64'
+    elif re.match('aarch64_be$', a):            return 'aarch64'
+    elif re.match('aarch64_ilp32$', a):         return 'aarch64'
+    elif re.match('aarch64_be_ilp32$', a):      return 'aarch64'
+    elif re.match('mips(isa|)(32|64|)(r6|)(el|)$', a):      return 'mips'
+    elif re.match('p(pc|owerpc)', a):           return 'ppc'
+    elif re.match('p(pc64|owerpc64)', a):       return 'ppc64'
+    elif re.match('riscv64$', a):               return 'riscv64'
+    elif a in valid_archs:                      return a
+    else:
+        if not d.getVar("TARGET_OS").startswith("linux"):
+            return a
+        bb.error("cannot map '%s' to a linux kernel architecture" % a)
+
+export ARCH = "${@map_kernel_arch(d.getVar('TARGET_ARCH'), d)}"
+
+CFLAGS += "-Iarch/${ARCH}"
+
+EXTRA_OEMAKE = "CFLAGS='${CFLAGS}' LDFLAGS='${LDFLAGS}'"
+
+do_compile() {
+    oe_runmake ARCH=${ARCH}
+}
+
+do_install() {
+    oe_runmake ARCH="${ARCH}" DESTDIR="${D}" install
+}