Looks good.
/Erik
On 2015-05-08 09:57, Magnus Ihse Bursie wrote:
On 2015-04-20 09:02, Erik Joelsson wrote:
Looks good to me.
Thanks Erik.
Unfortunately, I never got round to pushing this. In the meantime, the
codebase evolved, and I had to add a couple of more disabled warnings.
I also modified the help text on a failed build slightly.
Here's the updated webrev:
http://cr.openjdk.java.net/~ihse/JDK-8074859-warnings-as-errors/webrev.01
/Magnus
/Erik
On 2015-04-17 14:52, Magnus Ihse Bursie wrote:
With JDK-8074096, the number of warnings in the product was reduced
to a minimum. This enables the next step, which is turning on the
respective compiler flags that turns warnings into errors. In the
long run, this is the only way to keep the warnings from creeping back.
Even with JDK-8074096, the product does not build 100% warning free.
This is due to some warnings that cannot be disabled, or (in one
case) where C and C++ code is mixed, and warnings for both languages
cannot be used. A system similar to the one introduced in
JDK-8074096 is therefore needed, in which individual libraries can
be exempted from this flag, until such warnings are fixed. A library
can thus disable warnings as errors with WARNINGS_AS_ERRORS :=
false, or (better) use a toolchain-specific version, e.g
WARNINGS_AS_ERRORS_gcc := false. This is intended as a temporary
measure, though. The long-term solution is reasonably to fix the
warnings and remove that argument.
Also, different versions of compilers can generate a different set
of warnings. It is therefore necessary to be able to turn off this
globally. Therefor a new flag for configure is introduced:
--disable-warnings-as-errors.
While the code compiles without errors on the build systems used
internally at Oracle, this might not be the case on other
combinations of operating system versions and toolchain versions. To
facilitate for unexpecting developers, a help message is added if
the build fails, that suggests using --disable-warnings-as-errors.
This solution was chosen as a compromise between the "hard core"
solution of turning on warnings as errors by default for anyone, and
the cowar... erm, conservative solution of checking if the compiler
versions exactly match what's used inside Oracle (and therefore
regularly tested), and only turn it on in that case.
Similarly to JDK-8074096, I intend to file follow-up bugs for each
individual library that got a WARNINGS_AS_ERRORS_* := false.
Bug: https://bugs.openjdk.java.net/browse/JDK-8074859
WebRev for top:
http://cr.openjdk.java.net/~ihse/JDK-8074859-warnings-as-errors-top/webrev.01
WebRev for jdk:
http://cr.openjdk.java.net/~ihse/JDK-8074859-warnings-as-errors-jdk/webrev.01
Some comments:
* I needed to add a few more DISABLED_WARNINGS. For windows, this is
most likely due to the recent compiler change. For other libraries,
I'm not sure, but it might well be the result of recent changes that
has introduced new warnings. If so, it highlights the need of this
patch to keep the build warning free.
* For a few libraries and toolchains, there is *both*
WARNINGS_AS_ERRORS := false and a DISABLED_WARNINGS list. This is
the case if not all warnings are possible to disable.
* I have removed some incorrect uses of SHARED_LIBRARY_FLAGS. This
is included in our JDK LDFLAGS, so it should not be set separately,
and definitely not as CFLAGS. (This caused compiler warnings, which
now turned into errors.) However, a more suitable long-term solution
is probably to move the knowledge of how to create shared libraries
more specifically into SetupNativeCompilation, and not set it as
part of the JDK flags.
/Magnus
