RFR: JDK-8149110 Introduce DISABLED_WARNINGS for Java compilation

[Erik Joelsson]

Looks good.

/Erik

On 2020-03-12 03:21, Magnus Ihse Bursie wrote:
> For native code, we have a system to turn of individual warnings on a 
> per-library basis. We should have a similar system for Java compilation.
>
> The suggestion is to introduce a DISABLED_WARNINGS argument to 
> SetupJavaCompilation. We could then be able to express something like:
>
> jdk.xml.ws_DISABLED_WARNINGS := rawtypes deprecation finally
>
> to get the jdk.xml.ws module to compile with 
> '-Xlint:all,-rawtypes,-deprecation,-finally'
>
> On top of that, I have made sure that all Java compilations are done 
> with '-Xlint:all -Werror', and individual warnings are disabled on a 
> per-compilation basis. I have checked existing exceptions (using 
> -Xlint:-foo), and if they were not needed anymore, I have removed them.
>
> Here's a list of the remaining sinners, with one or more warnings 
> disabled.
>  * Multiple demos (really! Aren't they supposed to be role models for 
> how to code Java? :-o)
>  * Multiple build tools (interim langtools, jigsaw tools, and various 
> jdk build tools)
>  * jdk.hotspot.agent (almost all possible warnings...)
>  * jdk.rmic (deprecation)
>  * jdk.scripting.nashorn (removal -- yeah, we know...)
>  * jdk.jfr (exports)
>  * gensrc for jfr and jvmti
>  * visual studio project generator
>  * microbenchmark suite (tons of 'em)
>  * graal jtreg unit tests
>
> Ideally, these should be fixed for the corresponding Java sources. In 
> some cases this might not be possible, and if so, the warnings can 
> remain being disabled.
>
> The bug report also mentions:
>
> "As an addition, we can also filter out the annoying:
> Note: Some input files use or override a deprecated API.
> Note: Recompile with -Xlint:deprecation for details.
>
> and so finally achieve a true warning-free build."
>
> but I've decided to save that part for a separate patch.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8149110
> WebRev: 
> http://cr.openjdk.java.net/~ihse/JDK-8149110-introduce-DISABLE_WARNINGS-for-java/webrev.01
>
> /Magnus