libtool tries to guess the --tag value based on CC/CXX environment
variables and the compile commandline generated by makefiles. This
heuristics however fails when we construct CC variables in OE
and add security flags to it, especially -fPIE -pie which are added
by external compilers e.g. clang particularly. It fails because
libtool removed PIE flags from compiler cmdline intelligently
if it figures out that its building a library, which means that
the CC variable passed from cmdline does not match with the compiler
cmdline constructed by libtool and we end up with errors like
| arm-bec-linux-musleabi-libtool: compile: unable to infer tagged configuration
| arm-bec-linux-musleabi-libtool: error: specify a tag with '--tag'
This works with internal gcc toolchain because we configure gcc for
PIE when hardening is selected and dont pass -fPIE -pie options explicitly
but this is not an option for clang, and some external gcc toolchains
using older gcc
This patch adds the --tag option to help libtool set correct tags
in packages where it cant get it right via its heuristics
(From OE-Core rev: 0505075ae8d339ba097aebb82b4d0ae62f87c0a9)
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
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