[foreign-memaccess+abi] RFR: Tweak support for restricted methods

[Maurizio Cimadamore]

On Mon, 25 Sep 2023 10:46:58 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> This patch addresses two issues:
>> * The javadoc for all restricted methods includes a sentence which states that developers should seek alternatives. This sentence is now removed.
>> * As outlined [here](https://bugs.openjdk.org/browse/JDK-8307341), the warning message for restricted method calls should include the caller class name (where possible) and an additional lines about restricted method warnings turning into errors at some point in the future.
>
> src/java.base/share/classes/java/lang/Module.java line 324:
> 
>> 322:                 String mod = isNamed() ? "module " + getName() : "an unnamed module";
>> 323:                 String modflag = isNamed() ? getName() : "ALL-UNNAMED";
>> 324:                 String caller = currentClass != null ?
> 
> There are cases where the caller class might be null (e.g. when a restricted method is called by a native method that is attached to the JVM). In such cases we omit the "by" section.

Examples (from the test):

WARNING: A restricted method in java.lang.foreign.Linker has been called
WARNING: java.lang.foreign.Linker::downcallHandle has been called by org.openjdk.foreigntest.PanamaMainDirect in module panama_module
WARNING: Use --enable-native-access=panama_module to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

vs.

WARNING: A restricted method in java.lang.foreign.Linker has been called
WARNING: java.lang.foreign.Linker::downcallHandle has been called in an unnamed module
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

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PR Review Comment: https://git.openjdk.org/panama-foreign/pull/896#discussion_r1335716860