Build change looks ok. I will leave it for someone better versed in C++
for the code changes.
/Erik
On 2018-09-24 13:31, Magnus Ihse Bursie wrote:
The -Wextra option to gcc enables a bunch of useful warnings.[1] Some
of them, but not all, can be individually enabled or disabled. All
other libraries in OpenJDK are compiled with -Wextra, but not Hotspot.
Enabling -Wextra on Hotspot triggers a couple of warnings for zero
that can be individually disabled.
However, -Wextra also includes some check that cannot be disabled
individually, so to be able to add this, we must at the same time fix
those warnings.
The warnings that cannot be disabled and which have been triggered in
Hotspot is "enumeral and non-enumeral type in conditional expression"
and "base class should be explicitly initialized in the copy
constructor". The former complains about mixing enums and integers in
the tertiary operator (x ? enum_val : int_val). If you think that gcc
is a bit too picky here, I agree. It's not obvious per se that the
added casts improve the code. However, this is the price we need to
pay to be able to enable -Wextra, and *that* is something that is
likely to improve the code.
The second warning about the copy constructor is, for what I can tell,
a highly valid warning and the code it warned on was indeed broken. As
far as I can tell, in a derived copy constructor you should always
explicitly initialize the base class.
Bug: https://bugs.openjdk.java.net/browse/JDK-8211073
WebRev:
http://cr.openjdk.java.net/~ihse/JDK-8211073-remove-Wno-extra-from-hotspot/webrev.01
/Magnus
[1] https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
