Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8039214

Inference should not map capture variables to their upper bounds

    XMLWordPrintable

Details

    • b53
    • Verified

    Backports

      Description

        When Types.containsType encounters a capture variable, testing for containment by an upper-bounded wildcard, it tests that the capture variable's upper bound is a subtype of the wildcard bound. This leads to incorrect inference results.

        E.g.,

        [CAP extends String] contained by [? extends alpha]
        becomes
        String <: alpha

        Here's an example that should compile but does not:

          interface I<X1,X2> {}
          class C<T> implements I<T,T> {}

          <X> void m(I<? extends X, X> arg) {}

          void test(C<?> arg) {
            m(arg);
          }

        Here's an example that should not compile, but does (see also JDK-8039210):

          static class D<T> {
            void inject(T arg) {}
            static <T> D<T> make(Class<? extends T> c) { return new D<T>(); }
          }

          void test(Object o) {
            D.make(o.getClass()).inject(o);
          }

        javac behavior appears to be the same in 6, 7, and 8.

        The offending implementation code is in 'visitWildcardType', which maps 's' to its capture var upper bound.

        IMPORTANT: fixing this bug will break the build of jax-ws. So JDK-8039210 must be resolved first.

        Attachments

          Issue Links

            backported by

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8046236 Inference should not map capture variables to their upper bounds

            • P3 - Major loss of function.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8085348 Inference should not map capture variables to their upper bounds

            • P3 - Major loss of function.
            • Resolved
            blocks

            Bug - A problem which impairs or prevents the functions of the product. JDK-8047797 Incorrect error: incompatible types: cannot infer type-variable(s) T#1,CAP#1,T#2

            • P3 - Major loss of function.
            • Resolved
            duplicates

            Bug - A problem which impairs or prevents the functions of the product. JDK-8028774 javac, inference don't seem to deal with target types in a consistent way

            • P3 - Major loss of function.
            • Resolved

            Bug - A problem which impairs or prevents the functions of the product. JDK-8043914 Inference failure involving capture inference variable

            • P3 - Major loss of function.
            • Resolved

            Bug - A problem which impairs or prevents the functions of the product. JDK-8067858 Method hiding regression

            • P3 - Major loss of function.
            • Resolved
            is blocked by

            Bug - A problem which impairs or prevents the functions of the product. JDK-8039210 Fix type error in DefaultResourceInjector

            • P3 - Major loss of function.
            • Resolved

            Enhancement - null JDK-8042338 Refactor Types.upperBound to treat wildcards and variables separately

            • P5 - Cosmetic problem like misspelt words or misaligned text.
            • Closed
            relates to

            Bug - A problem which impairs or prevents the functions of the product. JDK-8016196 Inference: define supertype parameterization for wildcard-parameterized types

            • P3 - Major loss of function.
            • Open

            Bug - A problem which impairs or prevents the functions of the product. JDK-8046762 Revert some inference fixes in JDK-8033718

            • P3 - Major loss of function.
            • Resolved

            Bug - A problem which impairs or prevents the functions of the product. JDK-8152894 Incorrect raw type warning for method reference

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved

            Bug - A problem which impairs or prevents the functions of the product. JDK-8075520 Varargs access check mishandles capture variables

            • P3 - Major loss of function.
            • Closed

            Bug - A problem which impairs or prevents the functions of the product. JDK-8159680 Inference failure with unchecked subtyping and arrays

            • P3 - Major loss of function.
            • Closed

            Bug - A problem which impairs or prevents the functions of the product. JDK-8170885 18.4: Avoid inferring capture variables during resolution

            • P3 - Major loss of function.
            • Open

            Bug - A problem which impairs or prevents the functions of the product. JDK-6893625 Generics case does not compile

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Open

            Bug - A problem which impairs or prevents the functions of the product. JDK-8012039 enum type variable not within its bound

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Open

            Bug - A problem which impairs or prevents the functions of the product. JDK-8160244 skip capture conversion before subtyping if types are parameterizations of the same class or interface

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Open

            Bug - A problem which impairs or prevents the functions of the product. JDK-8166437 Regression in javac - inferring generic types in Guava

            • P2 - Crashes, loss of data, severe memory leak.
            • Resolved

            Bug - A problem which impairs or prevents the functions of the product. JDK-8051402 javac, type containment should accept that CAP <= ? extends CAP and CAP <= ? super CAP

            • P3 - Major loss of function.
            • Resolved

            Bug - A problem which impairs or prevents the functions of the product. JDK-8143396 type inference regression

            • P3 - Major loss of function.
            • Resolved

            Bug - A problem which impairs or prevents the functions of the product. JDK-8055681 Javac unable to resolve method

            • P2 - Crashes, loss of data, severe memory leak.
            • Closed

            Bug - A problem which impairs or prevents the functions of the product. JDK-8033718 Inference ignores capture variable as upper bound

            • P3 - Major loss of function.
            • Closed

            Bug - A problem which impairs or prevents the functions of the product. JDK-8075793 Source incompatibility for inference using -source 7

            • P3 - Major loss of function.
            • Closed

            Bug - A problem which impairs or prevents the functions of the product. JDK-8133118 Incompatible static wildcard bounds

            • P3 - Major loss of function.
            • Closed

            Bug - A problem which impairs or prevents the functions of the product. JDK-8133916 Regression in inference for array type with wildcard

            • P3 - Major loss of function.
            • Closed

            Activity

              People

                dlsmith Dan Smith
                dlsmith Dan Smith
                Votes:
                0 Vote for this issue
                Watchers:
                4 Start watching this issue

                Dates

                  Created:
                  Updated:
                  Resolved: