8290561: Coalesce incubator-module warnings for single-file source-code programs

[lahodaj]

Consider a trivial code like:

public class Main {
     public static void main(String... args) {}
}

And an execution like:

$ java --add-modules jdk.incubator.concurrent Main.java 
WARNING: Using incubator modules: jdk.incubator.concurrent
warning: using incubating module(s): jdk.incubator.concurrent
1 warning

Having two warnings (one from runtime, one from javac) seems unnecessary. The patch proposed herein tries to avoid the javac warning, keeping only the runtime one. The conditions under which an incubator module is ignored w.r.t. this warning are:

• the boot Module layer has the module (hence, presumably, the runtime already provided the warning)
• the javac run is (likely) from the source launcher. This is being done using a custom javac option, -XDsourceLauncher (which can possibly be used in other cases).

This is to avoid cases where we would incorrectly suppress the incubator warning, e.g. when -XDsourceLauncher would be passed on the command line.

There are other ways to attempt to detect javac invocations from the source launcher - a distinct file manager is used by the source launcher (but detection of the specific file manager does not feel in line with general javac approach); or use of the jdk.internal.javac.source system property set by the native launcher (but this is only set when --source option is used, as far as I know, and javac also typically does not check system properties).

Note that there is JDK-8290563 to improve the text of the javac warning.

---

Progress

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Issue

• JDK-8290561: Coalesce incubator-module warnings for single-file source-code programs

Reviewers

• Maurizio Cimadamore (@mcimadamore - Reviewer)

Reviewing

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[mcimadamore]

Looks good!

[openjdk]

@lahodaj This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8290561: Coalesce incubator-module warnings for single-file source-code programs

Reviewed-by: mcimadamore

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 568 new commits pushed to the master branch:

• 32f4dc8: 8293295: Add type check asserts to java_lang_ref_Reference accessors
• e945619: 8293088: Fix compilation with the new Visual Studio preprocessor
• 730ced9: 8292660: C2: blocks made unreachable by NeverBranch-to-Goto conversion are removed incorrectly
• 3464019: 8292899: CustomTzIDCheckDST.java testcase failed on AIX platform
• e92b9e4: 8293325: Minor improvements to macos catch_mach_exception_raise() error handling
• 767262e: 8292201: serviceability/sa/ClhsdbThreadContext.java fails with "'Thread "Common-Cleaner"' missing from stdout/stderr"
• a366e82: 7113208: Incorrect javadoc on java.net.DatagramPacket.setLength()
• ac05bc8: 8293293: Move archive heap loading code out of heapShared.cpp
• e1e6732: 8293319: [C2 cleanup] Remove unused other_path arg in Parse::adjust_map_after_if
• 5757e21: 8292385: assert(ctrl == kit.control()) failed: Control flow was added although the intrinsic bailed out
• ... and 558 more: https://git.openjdk.org/jdk/compare/87340fd5408d89d9343541ff4fcabde83548a598...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[lahodaj]

/integrate

[openjdk]

Going to push as commit 26f2a97.
Since your change was applied there have been 585 commits pushed to the master branch:

• 8e22f2b: 8293361: GHA: dump config.log in case of configure failure
• b17758a: 8247283: Enable the new conformant preprocessor option in Visual Studio
• 1bed23a: 8293353: [BACKOUT] G1: Remove redundant is-marking-active checks in C1 barrier
• 4955835: 8282434: Leading combining diacritic character in string renders incorrectly
• ef20ffe: 8293159: Use try-with-resources in X11FontManager.registerFontDir
• 056ed48: 8293180: JQuery UI license file not updated
• dbb2c4b: 8288897: Clean up node dump code
• 9833c02: 8292946: GC lock/jni/jnilock001 test failed "assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed()) failed: Twice in a row"
• d753658: 8293107: GHA: Bump to Ubuntu 22.04
• d4e3e69: 8293344: JDK-8242181 broke stack printing for non-attached threads
• ... and 575 more: https://git.openjdk.org/jdk/compare/87340fd5408d89d9343541ff4fcabde83548a598...master

Your commit was automatically rebased without conflicts.

[openjdk]

@lahodaj Pushed as commit 26f2a97.

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