Move libssp into musl out of GCC

The motivations for this are complicated, but on musl systems, musl
will use its own libssp implementation, so GCC's libssp is not required.

Not to mention that GCC's libssp implementation is questionable at best.

This is the approach taken by the two major musl distributions - Alpine
Linux and Void Linux.

sysa/SHA256SUMS.pkgs

@@ -48,7 +48,7 @@ d7b7453ad400eac1ba39f99971afdc392cb8a92c557ef5d6fd9fa2625124de4a  ed-1.4_0.tar.b
 408131b1c033a5f8a6845997b049784be0b466cec107a71270e5a04dae2c1e6c  flex-2.6.4_0.tar.bz2
 5ff7fbe16b55563719b108260bd6a34ebabab0465d758ca98cba522932532e45  gawk-3.0.4_0.tar.bz2
 6de1c1380026ef9948387e665610185b6014f47a80453177a6c81898c95cbbd3  gc-8.0.4_0.tar.bz2
-4ed230542823160a4b1a469847cc2cc0ae1985611f2e1b831e13f2a3a7122efb  gcc-10.4.0_0.tar.bz2
+cb1aca35878f7c53e7dc96294ceca2ce3c72cf89359fe2bec46336d5f0849387  gcc-10.4.0_0.tar.bz2
 b09580c3972ff4e5f6e624bdc83d5328ce017422e0b92a7c170b51b6f04a47d2  gcc-4.0.4_0.tar.bz2
 58d0d431bb2e96a273965b5e7aa760fb6961a7f7f2fd98ef5fc5a6b7b44bc989  gcc-4.0.4_1.tar.bz2
 a2301d8dbbfbfcdd18444f01848e8e4366780281009640acbd3af0fab9b11aea  gcc-4.7.4_0.tar.bz2
@@ -79,7 +79,7 @@ a724c91a43e282c3d338a977e4eeac3b970df241db7872f9d5cf27984b609814  musl-1.1.24_0.
 b79e0f8a39ba8880d43aa27551b72915655c62af39125e1f4ac8f8e69e71aaca  musl-1.1.24_2.tar.bz2
 a675ead0f146a96973fca9cc9e4f16081b14c26630ae17405e3ba5e9510ff30d  musl-1.2.3_0.tar.bz2
 054c6a5f1c07d124b701e590267aa8fb2ba1c88bed9a69a473724f8534cdb728  musl-1.2.3_1.tar.bz2
-3260f0c8bfa1160a2f252c6e0d3ca5f98635ec8f9d9f211a30ef1a0313cac853  musl-1.2.3_2.tar.bz2
+5ba73e250b0325f690b2c5c3afd4a14cf4612c682e9b358727ebcb7bc6b758ef  musl-1.2.3_2.tar.bz2
 e0c91898e771c65e6a462600243a7858b069db5726680193f86d7dbac3f740ae  openssl-1.1.1l_0.tar.bz2
 69daf6ffbf26fea500426c6936e5a16e82833f03ad0dc6109697f69a8516b4c7  patch-2.7.6_0.tar.bz2
 914a7abf36a64723b6e9f9b0b6ccd19c8e544fa798896a2bb1151dc341890c22  perl-5.000_0.tar.bz2

sysc/gcc-10.4.0/gcc-10.4.0.sh

@@ -95,5 +95,6 @@ src_configure() {
         --disable-sjlj-exceptions \
         --disable-multilib \
         --enable-threads=posix \
-        --disable-libsanitizer
+        --disable-libsanitizer \
+        --disable-libssp
 }

sysc/musl-1.2.3/files/__stack_chk_fail_local.c

@@ -0,0 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2020 Timo Teräs <timo.teras@iki.fi>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+extern void __stack_chk_fail(void);
+void __attribute__((visibility ("hidden"))) __stack_chk_fail_local(void) { __stack_chk_fail(); }

sysc/musl-1.2.3/musl-1.2.3.sh

@@ -14,11 +14,19 @@ src_configure() {
 
 src_compile() {
     make "${MAKEJOBS}" CROSS_COMPILE=
+
+    # Provide libssp_nonshared.a to avoid GCC's messy libssp
+    # (Taken from Alpine Linux)
+    gcc -c __stack_chk_fail_local.c -o __stack_chk_fail_local.o
+    ar r libssp_nonshared.a __stack_chk_fail_local.o
 }
 
 src_install() {
     default
 
+    # Install libssp_nonshared.a
+    install -m 644 libssp_nonshared.a "${DESTDIR}${PREFIX}/lib/"
+
     # Make dynamic linker symlink relative in ${PREFIX}/lib
     rm "${DESTDIR}/lib/ld-musl-i386.so.1"
     rmdir "${DESTDIR}/lib"