hg: lambda/lambda/langtools: Enhancement: Add support for more aggressive type-inference

Andrew Hughes ahughes at redhat.com
Mon Aug 6 11:15:07 PDT 2012 

----- Original Message -----
> To further highlight what Erik said:
> 
> javac handles lint -Werror differently depending on wether the file
> is being compiled explicitly or implicitly. Files which are being
> compiled because they are referenced by explicitly compiled files
> will not generate warnings or cause -Werror to stop the compilation.
> 
> In incremental compilation situations this can result in surprising
> failures because some files containing warnings were compiled
> implicitly in a full build.
> 
> There's been suggestions to treat warnings in implicit and explicit
> files the same (which would certainly break the current build) and
> also to allow disabling of implicit compilation (which would also
> break the current build). Both of these would eventually help avoid
> introducing unrecognized warnings in the future but require that the
> warnings cleanup be complete in order to be usable.
> 

That definitely sounds like the right way to go to me, as having random
errors appearing because a file just happens to have not been compiled
on this build, but was on the previous one, is very confusing.

I'd say -Werror should be turned on in one central place and not by default.
Those who want to catch such errors can build with it on, without it affecting
general users just building OpenJDK and others not interested in fixing warnings
right at this moment.  This is how other FOSS projects I've seen handle it.

The same goes for -Xlint:all and other options.  Having different options for
different sets of files makes things confusing and really hard to maintain.

> Mike
> 
> On Aug 6 2012, at 04:03 , Erik Joelsson wrote:
> 
> > We haven't addressed the problem of applying the correct warning
> > levels on the java compilation yet. Hopefully we will be able to
> > readd the correct -Xlint flags to an approximation of the correct
> > set of source files. This is tricky because of implicit
> > compilation and the old build suffers from this too.
> > 
> > /Erik
> > 
> > On 2012-08-03 19:06, Maurizio Cimadamore wrote:
> >> Not sure what happened here - when building the lambda repository
> >> using the new build, I do not get errors in certain files -
> >> either those files are not being compiled, or the -Xlint flag is
> >> not passed to the compiler.
> >> 
> >> Maurizio
> >> 
> >> 
> >> -------- Original Message --------
> >> Subject:     Re: hg: lambda/lambda/langtools: Enhancement: Add
> >> support for more aggressive type-inference
> >> Date:     Fri, 03 Aug 2012 15:27:45 +0100
> >> From:     Maurizio Cimadamore <maurizio.cimadamore at oracle.com>
> >> Organization:     Oracle
> >> To:     Henri Gomez <henri.gomez at gmail.com>
> >> CC:     lambda-dev at openjdk.java.net
> >> 
> >> 
> >> 
> >> On 03/08/12 15:11, Maurizio Cimadamore wrote:
> >>> Good catch - the compiler now catches more 'redundant casts' as a
> >>> side-effect of a change I made... I will correct this (and other
> >>> issues)
> >>> asap
> >> Interesting - this is not caught by the new build system (the one
> >> I used
> >> to check that everything was ok)...
> >> 
> >> Maurizio
> >>> Maurizio
> >>> 
> >>> On 03/08/12 14:11, Henri Gomez wrote:
> >>>> Everything has been commited ?
> >>>> 
> >>>> Got following build error :
> >>>> 
> >>>> ../../../../src/share/classes/sun/security/x509/CertParseError.java
> >>>> # Running javac:      150 files; in
> >>>> /Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/jdk/make/sun/security/other
> >>>> /Library/Java/JavaVirtualMachines/1.7.0u6.jdk/Contents/Home/bin/java
> >>>> -XX:-PrintVMOptions -XX:+UnlockDiagnosticVMOptions
> >>>> -XX:-LogVMOutput
> >>>> -Djava.awt.headless=true -Xmx512m -Xms512m -XX:PermSize=32m
> >>>> -XX:MaxPermSize=160m
> >>>> -Xbootclasspath/p:/Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/build/macosx-x86_64/langtools/dist/bootstrap/lib/javac.jar
> >>>> -jar
> >>>> /Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/build/macosx-x86_64/langtools/dist/bootstrap/lib/javac.jar
> >>>> -Werror -Xlint:all,-deprecation -Xlint:all -Xlint:-path -source
> >>>> 8
> >>>> -target 8 -encoding ascii
> >>>> -Xbootclasspath:/Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/build/macosx-x86_64/classes
> >>>> -sourcepath
> >>>> /Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/build/macosx-x86_64/gensrc:::/Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/jdk/src/macosx/classes:/Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/jdk/src/solaris/classes:/Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/jdk/src/share/classes
> >>>> -d
> >>>> /Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/build/macosx-x86_64/classes
> >>>> @/Users/henri/Documents/jenkins/data/jobs/openjdk-jdk8-lambda/workspace/build/macosx-x86_64/tmp/sun/sun.security.other/.classes.list.filtered
> >>>> ../../../../src/share/classes/sun/security/provider/certpath/PKIX.java:252:
> >>>> warning: [cast] redundant cast to Collection<? extends
> >>>> Certificate>
> >>>>                          (Collection<? extends Certificate>)
> >>>>                          ^
> >>>> error: warnings found and -Werror specified
> >>>> Note: Some input files use or override a deprecated API.
> >>>> Note: Recompile with -Xlint:deprecation for details.
> >>>> 1 error
> >>>> 1 warning
> >>>> make[5]: *** [.compile.classlist] Error 1
> >>>> make[4]: *** [all] Error 1
> >>>> make[3]: *** [all] Error 1
> >>>> make[2]: *** [all] Error 1
> >>>> make[1]: *** [jdk-build] Error 2
> >>>> 
> >>>> 
> >>>> 2012/8/3 <maurizio.cimadamore at oracle.com>:
> >>>>> Changeset: 56419f06ad92
> >>>>> Author:    mcimadamore
> >>>>> Date:      2012-08-03 12:48 +0100
> >>>>> URL:
> >>>>>       http://hg.openjdk.java.net/lambda/lambda/langtools/rev/56419f06ad92
> >>>>> 
> >>>>> Enhancement: Add support for more aggressive type-inference
> >>>>> 
> >>>>> Experimental aggressive inference support can be enabled using
> >>>>> the flag -XDuseGraphInference.
> >>>>> The new inferencer (disabled by default) solves a number of
> >>>>> outstanding problems in the legacy JDK 5/6/7 type-inferencer
> >>>>> (which means it is also slightly backwards incompatible).
> >>>>> 
> >>>>> Examples:
> >>>>> 
> >>>>> *) Foo<Number> fn = new Foo<>(1);
> >>>>> 
> >>>>> *) Set<String> ss = listInt.map(x->x.toString()).into(new
> >>>>> HashSet<>);
> >>>>> 
> >>>>> *) <Z> void call(SAM<Z> x, SAM<Z> y) { ... }
> >>>>>     call(() -> Collections.emptyList(), () -> new
> >>>>>     ArrayList<String>());
> >>>>> 
> >>>>> Misc fixes:
> >>>>> *) remove unused class in com/sun/runtime
> >>>>> *) fix build.properties to generate right amount of stubs
> >>>>> *) fix regression tests failures triggered when running against
> >>>>> lambda binary snapshot
> >>>>> 
> >>>>> ! make/build.properties
> >>>>> - src/share/classes/com/sun/runtime/DefenderMethod.java
> >>>>> ! src/share/classes/com/sun/tools/javac/code/Source.java
> >>>>> ! src/share/classes/com/sun/tools/javac/code/Symtab.java
> >>>>> ! src/share/classes/com/sun/tools/javac/code/Type.java
> >>>>> ! src/share/classes/com/sun/tools/javac/code/Types.java
> >>>>> ! src/share/classes/com/sun/tools/javac/comp/Attr.java
> >>>>> ! src/share/classes/com/sun/tools/javac/comp/Check.java
> >>>>> ! src/share/classes/com/sun/tools/javac/comp/DeferredAttr.java
> >>>>> + src/share/classes/com/sun/tools/javac/comp/GraphInfer.java
> >>>>> ! src/share/classes/com/sun/tools/javac/comp/Infer.java
> >>>>> + src/share/classes/com/sun/tools/javac/comp/InferFactory.java
> >>>>> + src/share/classes/com/sun/tools/javac/comp/LegacyInfer.java
> >>>>> ! src/share/classes/com/sun/tools/javac/comp/Resolve.java
> >>>>> !
> >>>>> src/share/classes/com/sun/tools/javac/resources/compiler.properties
> >>>>> ! src/share/classes/com/sun/tools/javac/util/List.java
> >>>>> ! test/tools/javac/6758789/T6758789b.out
> >>>>> ! test/tools/javac/Diagnostics/6722234/T6722234b_1.out
> >>>>> ! test/tools/javac/Diagnostics/6722234/T6722234b_2.out
> >>>>> ! test/tools/javac/Diagnostics/6799605/T6799605.out
> >>>>> ! test/tools/javac/api/TestJavacTaskScanner.java
> >>>>> ! test/tools/javac/cast/7123100/T7123100a.out
> >>>>> ! test/tools/javac/defender/Pos01.java
> >>>>> ! test/tools/javac/diags/examples.not-yet.txt
> >>>>> ! test/tools/javac/diags/examples/CantApplyDiamond1.java
> >>>>> +
> >>>>> test/tools/javac/diags/examples/IncompatibleEqUpperBounds.java
> >>>>> ! test/tools/javac/diags/examples/IncompatibleTypes1.java
> >>>>> +
> >>>>> test/tools/javac/diags/examples/InferNoConformingAssignment.java
> >>>>> -
> >>>>> test/tools/javac/diags/examples/InferredDoNotConformToBounds.java
> >>>>> + test/tools/javac/diags/examples/InferredDoNotConformToEq.java
> >>>>> +
> >>>>> test/tools/javac/diags/examples/InferredDoNotConformToLower.java
> >>>>> +
> >>>>> test/tools/javac/diags/examples/InferredDoNotConformToUpper.java
> >>>>> ! test/tools/javac/diags/examples/WhereCaptured.java
> >>>>> ! test/tools/javac/diags/examples/WhereCaptured1.java
> >>>>> ! test/tools/javac/generics/7015430/T7015430.out
> >>>>> ! test/tools/javac/generics/7151802/T7151802.out
> >>>>> ! test/tools/javac/generics/diamond/neg/Neg06.out
> >>>>> ! test/tools/javac/generics/diamond/neg/Neg07.out
> >>>>> ! test/tools/javac/generics/diamond/neg/Neg10.java
> >>>>> ! test/tools/javac/generics/diamond/neg/Neg10.out
> >>>>> ! test/tools/javac/generics/inference/6315770/T6315770.out
> >>>>> ! test/tools/javac/generics/inference/6611449/T6611449.out
> >>>>> ! test/tools/javac/generics/inference/6638712/T6638712b.out
> >>>>> ! test/tools/javac/generics/inference/6638712/T6638712d.out
> >>>>> ! test/tools/javac/generics/inference/6638712/T6638712e.out
> >>>>> ! test/tools/javac/generics/inference/6650759/T6650759m.out
> >>>>> ! test/tools/javac/generics/inference/7086601/T7086601a.out
> >>>>> ! test/tools/javac/lambda/TargetType10.java
> >>>>> ! test/tools/javac/lambda/TargetType10.out
> >>>>> ! test/tools/javac/lambda/TargetType20.java
> >>>>> ! test/tools/javac/lambda/TargetType20.out
> >>>>> ! test/tools/javac/multicatch/Neg07.out
> >>>>> 
> >>>>> 
> >>> 
> >> 
> >> 
> >> 
> >> 
> >> 
> 
> 

-- 
Andrew :)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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