misc: Appease GCC 8

GCC 8 adds a number of new warnings to -Wall which generate errors.

- Fix memset to 0 for structs by adding casts.
- Fix cast with const when the const was ignored.
- Fix catch a polymorphic type by value

We now compile with GCC 8!

Change-Id: Iab70ce11190eee67608fc25c0bedff170152b153
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/11949
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

2 files changed, 5 insertions, 1 deletions

diff --git a/src/arch/x86/decoder.hh b/src/arch/x86/decoder.hh
index 3630ea8c8..c0b30b5e8 100644
--- a/src/arch/x86/decoder.hh
+++ b/src/arch/x86/decoder.hh
@@ -239,7 +239,7 @@ class Decoder
         outOfBytes(true), instDone(false),
         state(ResetState)
     {
-        memset(&emi, 0, sizeof(emi));
+        emi.reset();
         mode = LongMode;
         submode = SixtyFourBitMode;
         emi.mode.mode = mode;
diff --git a/src/arch/x86/types.hh b/src/arch/x86/types.hh
index 6e1b1cf2f..f2b064650 100644
--- a/src/arch/x86/types.hh
+++ b/src/arch/x86/types.hh
@@ -199,6 +199,10 @@ namespace X86ISA
     //The intermediate structure used by the x86 decoder.
     struct ExtMachInst
     {
+        void reset() {
+            memset(static_cast<void *>(this), 0, sizeof(*this));
+        }
+
         //Prefixes
         LegacyPrefixVector legacy;
         Rex rex;