[OE-core] [PATCH 3/4] gcc-runtime: Disable gcc version of libssp

[Khem Raj]

libssp is implemented fully in glibc as well as in musl
so we really do not need the gcc version of this library
except may be for mingw, where we keep it enabled anyway
gcc in OE is built with the knowledge that C library
already provides libssp implementation, we should therefore
not need the gcc implementation of same.

libssp_nonshared piece is a detail which is needed when gcc
is the compiler, in glibc this is part of libc_nonshared.a
already and libc_nonshared.a is linked always when linking
with -lc becuase libc.so in glibc is actually a linker script

GROUP ( /usr/lib/libc.so.6 /usr/lib/libc_nonshared.a  AS_NEEDED ( /usr/lib/ld-linux-x86-64.so.2 ) )

which automatically links in the needed runtime bits, this however
is not the case for musl, where core SSP APIs are implemented in full
but compiler specific runtime isn't, for this we add a new package
called libssp_nonshared which generate the needed runtime stub
and gcc is already carrying patch to link to libssp_nonshared.a
on musl

This should fix a long standing problem where static PIE executable
were not buildable with OE since it was conflicting SSP implementation
one from C library and the other one from gcc and we end up with
duplicate symbol errors during linking.

Signed-off-by: Khem Raj <raj.khem at gmail.com>
---
 meta/recipes-devtools/gcc/gcc-7.3.inc     | 4 +++-
 meta/recipes-devtools/gcc/gcc-runtime.inc | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/meta/recipes-devtools/gcc/gcc-7.3.inc b/meta/recipes-devtools/gcc/gcc-7.3.inc
index d968c322d2..7e52afc643 100644
--- a/meta/recipes-devtools/gcc/gcc-7.3.inc
+++ b/meta/recipes-devtools/gcc/gcc-7.3.inc
@@ -93,10 +93,12 @@ FORTRAN = ""
 JAVA = ""
 
 LTO = "--enable-lto"
+SSP ?= "--disable-libssp"
+SSP_mingw = "--enable-libssp"
 
 EXTRA_OECONF_BASE = "\
     ${LTO} \
-    --enable-libssp \
+    ${SSP} \
     --enable-libitm \
     --disable-bootstrap \
     --disable-libmudflap \
diff --git a/meta/recipes-devtools/gcc/gcc-runtime.inc b/meta/recipes-devtools/gcc/gcc-runtime.inc
index 97365a21dc..b4e5539575 100644
--- a/meta/recipes-devtools/gcc/gcc-runtime.inc
+++ b/meta/recipes-devtools/gcc/gcc-runtime.inc
@@ -24,8 +24,10 @@ RUNTIMELIBITM_nios2 = ""
 RUNTIMELIBITM_microblaze = ""
 RUNTIMELIBITM_riscv32 = ""
 RUNTIMELIBITM_riscv64 = ""
+RUNTIMELIBSSP ?= ""
+RUNTIMELIBSSP_mingw ?= "libssp"
 
-RUNTIMETARGET = "libssp libstdc++-v3 libgomp libatomic ${RUNTIMELIBITM} \
+RUNTIMETARGET = "libstdc++-v3 libgomp libatomic ${RUNTIMELIBITM} \
     ${@bb.utils.contains_any('FORTRAN', [',fortran',',f77'], 'libquadmath', '', d)} \
 "
 RUNTIMETARGET_append_x86 = " libmpx"
-- 
2.17.0