BaseTools/tools_def: add "-fno-unwind-tables" to GCC_AARCH64_CC_FLAGS

The ElfConvert routines in GenFw don't handle the ".eh_frame" ELF section
emitted by gcc. For this reason, Leif disabled the generation of that
section for AARCH64 with "-fno-asynchronous-unwind-tables" in commit
28e80befa4fe [1], and Ard did the same for IA32 and X64 in commit
26ecc55c027d [2]. (The CLANG38 toolchain received the same flag at its
inception, in commit 6f756db5ea05 [3].)

However, ".eh_frame" is back now; in upstream gcc commit 9cbee213b579 [4]
(part of tag "gcc-8_1_0-release"), both "-fasynchronous-unwind-tables" and
"-funwind-tables" were made the default for AARCH64. (The patch author
described the effects on the gcc mailing list [5].) We have to counter the
latter flag with "-fno-unwind-tables", otherwise GenFw chokes on
".eh_frame" again (triggered for example on Fedora 28).

"-f[no-]unwind-tables" goes back to at least gcc-4.4 [6], so it's safe to
add to GCC_AARCH64_CC_FLAGS.

[1] https://github.com/tianocore/edk2/commit/28e80befa4fe
[2] https://github.com/tianocore/edk2/commit/26ecc55c027d
[3] https://github.com/tianocore/edk2/commit/6f756db5ea05
[4] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=9cbee213b579
[5] http://mid.mail-archive.com/7b28c03a-c032-6cec-c127-1c12cbe98eeb@foss.arm.com
[6] https://gcc.gnu.org/onlinedocs/gcc-4.4.7/gcc/Code-Gen-Options.html

Cc: "Danilo C. L. de Paula" <ddepaula@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Cole Robinson <crobinso@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Reported-by: "Danilo C. L. de Paula" <ddepaula@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Liming Gao <liming.gao@intel.com>

0 files changed, 0 insertions, 0 deletions