8290496: riscv: Fix build warnings-as-errors with GCC 11

[zifeihan]

Hi, Please review this backport to riscv-port-jdk17u.
Backport of JDK-8290496. Applies cleanly.
build config:

bash configure --with-debug-level=release --with-jvm-variants=minimal --with-zlib=system --with-native-debug-symbols=internal --with-boot-jdk=/home/zifeihan/jre/jre11 --with-extra-cxxflags=-Wno-maybe-uninitialized --with-extra-cflags=-Wno-maybe-uninitialized

Before this backport:

ERROR: Build failed for target 'default (exploded-image)' in configuration 'linux-riscv64-normal-minimal-release' (exit code 2)
Stopping sjavac server

=== Output from failing command(s) repeated here ===
* For target hotspot_variant-minimal_libjvm_objs_c1_LIRAssembler.o:
In file included from /home/zifeihan/riscv-port-jdk11u/src/hotspot/share/c1/c1_LIRAssembler.hpp:28,
                 from /home/zifeihan/riscv-port-jdk11u/src/hotspot/share/c1/c1_LIRAssembler.cpp:30:
In member function 'void PatchingStub::install(MacroAssembler*, LIR_PatchCode, Register, CodeEmitInfo*)',
    inlined from 'void LIR_Assembler::patching_epilog(PatchingStub*, LIR_PatchCode, Register, CodeEmitInfo*)' at /home/zifeihan/riscv-port-jdk11u/src/hotspot/share/c1/c1_LIRAssembler.cpp:45:17:
/home/zifeihan/riscv-port-jdk11u/src/hotspot/share/c1/c1_CodeStubs.hpp:423:25: error: 'this' pointer is null [-Werror=nonnull]
  423 |       n_move->set_offset(field_offset);
      |       ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
In file included from /home/zifeihan/riscv-port-jdk11u/src/hotspot/share/code/nativeInst.hpp:30,
                 from /home/zifeihan/riscv-port-jdk11u/src/hotspot/share/precompiled/precompiled.hpp:77:
/home/zifeihan/riscv-port-jdk11u/src/hotspot/cpu/riscv/nativeInst_riscv.hpp: In member function 'void LIR_Assembler::patching_epilog(PatchingStub*, LIR_PatchCode, Register, CodeEmitInfo*)':
/home/zifeihan/riscv-port-jdk11u/src/hotspot/cpu/riscv/nativeInst_riscv.hpp:419:8: note: in a call to non-static member function 'void NativeMovRegMem::set_offset(int)'
  419 |   void set_offset(int x);
      |        ^~~~~~~~~~
cc1plus: all warnings being treated as errors

* All command lines available in /home/zifeihan/riscv-port-jdk11u/build/linux-riscv64-normal-minimal-release/make-support/failure-logs.
=== End of repeated output ===

No indication of failed target found.
Hint: Try searching the build log for '] Error'.
Hint: See doc/building.html#troubleshooting for assistance.

make[1]: *** [/home/zifeihan/riscv-port-jdk11u/make/Init.gmk:308: main] Error 2
make: *** [/home/zifeihan/riscv-port-jdk11u/make/Init.gmk:186: default] Error 2

After this backport, We can build successful.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8290496: riscv: Fix build warnings-as-errors with GCC 11 (Bug - P4)

Reviewers

• Fei Yang (@RealFYang - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/riscv-port-jdk11u.git pull/7/head:pull/7
$ git checkout pull/7

Update a local copy of the PR:
$ git checkout pull/7
$ git pull https://git.openjdk.org/riscv-port-jdk11u.git pull/7/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 7

View PR using the GUI difftool:
$ git pr show -t 7

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/riscv-port-jdk11u/pull/7.diff

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[bridgekeeper]

👋 Welcome back gcao! A progress list of the required criteria for merging this PR into riscv-port will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

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

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

8290496: riscv: Fix build warnings-as-errors with GCC 11

Reviewed-by: fyang

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 42 new commits pushed to the riscv-port branch:

• 17e4f4e: Merge remote-tracking branch 'origin/master' into riscv-port
• 2a78f2f: Merge
• 5c5687d: 8322750: Test "api/java_awt/interactive/SystemTrayTests.html" failed because A blue ball icon is added outside of the system tray
• a4a5c7f: 8276125: RunThese24H.java SIGSEGV in JfrThreadGroup::thread_group_id
• f6e6eef: 8326938: [11u] JDK-8214908 broke two CTW tests
• a582e11: 8281507: Two javac tests have bad jtreg @clean tags
• b183cd2: 8314552: Fix javadoc tests to work with jtreg 7
• 0ae93db: 8323717: Introduce test keyword for tests that need external dependencies
• 61164ce: 8305962: update jcstress to 0.16
• f2565a6: 8324723: GHA: Upgrade some actions to avoid deprecated Node 16
• ... and 32 more: https://git.openjdk.org/riscv-port-jdk11u/compare/309291f166821443393818beed364de6f2de5c52...riscv-port

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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@RealFYang) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[mlbridge]

Webrevs

• 00: Full (461fec88)

[zifeihan]

/integrate

[RealFYang]

/sponsor

[openjdk]

@zifeihan
Your change (at version 461fec8) is now ready to be sponsored by a Committer.

[openjdk]

Going to push as commit c7fb513.
Since your change was applied there have been 42 commits pushed to the riscv-port branch:

• 17e4f4e: Merge remote-tracking branch 'origin/master' into riscv-port
• 2a78f2f: Merge
• 5c5687d: 8322750: Test "api/java_awt/interactive/SystemTrayTests.html" failed because A blue ball icon is added outside of the system tray
• a4a5c7f: 8276125: RunThese24H.java SIGSEGV in JfrThreadGroup::thread_group_id
• f6e6eef: 8326938: [11u] JDK-8214908 broke two CTW tests
• a582e11: 8281507: Two javac tests have bad jtreg @clean tags
• b183cd2: 8314552: Fix javadoc tests to work with jtreg 7
• 0ae93db: 8323717: Introduce test keyword for tests that need external dependencies
• 61164ce: 8305962: update jcstress to 0.16
• f2565a6: 8324723: GHA: Upgrade some actions to avoid deprecated Node 16
• ... and 32 more: https://git.openjdk.org/riscv-port-jdk11u/compare/309291f166821443393818beed364de6f2de5c52...riscv-port

Your commit was automatically rebased without conflicts.

[openjdk]

@RealFYang @zifeihan Pushed as commit c7fb513.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.