arch, arm: Fix implicit-fallthrough GCC warnings
authorChun-Chen Hsu <chunchenhsu@google.com>
Tue, 13 Mar 2018 09:44:52 +0000 (17:44 +0800)
committerChun-Chen TK Hsu <chunchenhsu@google.com>
Tue, 20 Mar 2018 20:17:00 +0000 (20:17 +0000)
commitfe187de9bd1aa479ab6cd198522bfd118d0d50ec
treebeb10d2550241e5f88e1bd7e153fc7b54da6ef1f
parent212649b01e90b28df6e1a66c1b98a944af5b05a9
arch, arm: Fix implicit-fallthrough GCC warnings

GCC 7 generates spurious fallthrough warnings in nested switch blocks
where the inner switch block return.  There is already a GCC fix [1]
submitted for review but, until it is merged into GCC trunk, GEM5 will
not build with GCC 7 due to these fallthrough warnings.  This patch
silences the spurious fallthrough warnings by appending a M5_UNREACHABLE
statement in the outer switch cases.

Note there is another GEM5 patch [2] to fix other fallthrough warnings.

[1] https://gcc.gnu.org/ml/gcc-patches/2018-02/msg01105.html
[2] https://gem5-review.googlesource.com/c/public/gem5/+/8541

Change-Id: I97cd8bfa90a88e93cee60cf27a8c93611d11a242
Signed-off-by: Chun-Chen Hsu <chunchenhsu@google.com>
Reviewed-on: https://gem5-review.googlesource.com/9101
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
src/arch/arm/isa/formats/aarch64.isa
src/arch/isa_parser.py