Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8157181

Compilers accept modification of final fields outside initializer methods

    XMLWordPrintable

Details

    • b127

    Backports

      Description

        According to the Java VM Specification, the putstatic bytecode is allowed to modify a final field only
        - (1) if the field is declared in the current class (the class that declares the current method) and
        - (2) if the putstatic instruction appears in the class or interface initializer method <clinit> of the current class.

        Otherwise an IllegalAccessError must be thrown.

        Similar, the putfield bytecode is allowed to modify a final field only
        - (1) if the field is declared in the current class and
        - (2) if the instruction appears in an instance initializer method <init> of the current class.

        Otherwise an IllegalAccesError must be thrown.

        Currently, HotSpot checks only condition (1) but not (2):
        http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/file/07a5eceac654/src/share/vm/interpreter/linkResolver.cpp#l910

        Methods that do not satisfy condition (2) violate the assumptions of the compilers. Compiling such methods results in different behavior of compiled and interpreted code (see a detailed example below).

        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-8183652 Compilers accept modification of final fields outside initializer methods

            • P2 - Crashes, loss of data, severe memory leak.
            • 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-8192216 Compilers accept modification of final fields outside initializer methods

            • P2 - Crashes, loss of data, severe memory leak.
            • 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-8161987 Compilers accept modification of final fields outside initializer methods

            • 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-8161988 Compilers accept modification of final fields outside initializer methods

            • 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-8161989 Compilers accept modification of final fields outside initializer methods

            • P3 - Major loss of function.
            • Closed
            blocks

            Bug - A problem which impairs or prevents the functions of the product. JDK-8159215 Tighten checks for final field updates

            • P3 - Major loss of function.
            • Closed
            relates to

            Bug - A problem which impairs or prevents the functions of the product. JDK-8159150 Constant folding final field accesses does not take class redefinition into account

            • 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-8160551 assert(c == Bytecodes::_putfield) failed: must be putfield

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

            Bug - A problem which impairs or prevents the functions of the product. JDK-8160527 Check for final instance field updates can be omitted

            • P3 - Major loss of function.
            • Resolved

            Activity

              People

                zmajo Zoltan Majo (Inactive)
                zmajo Zoltan Majo (Inactive)
                Votes:
                0 Vote for this issue
                Watchers:
                12 Start watching this issue

                Dates

                  Created:
                  Updated:
                  Resolved: