[jdk11u-dev] RFR: 8348597: Update HarfBuzz to 10.4.0 [v6]

[Andrew John Hughes]

On Thu, 21 Aug 2025 14:09:25 GMT, Antonio Vieiro <avieiro at openjdk.org> wrote:

>> Backport of [JDK-8348597](https://bugs.openjdk.org/browse/JDK-8348597) from JDK17 that updates HarfBuzz to 10.4.0 (which [improves drawing performande by 10+% and includes different build fixes](https://newreleases.io/project/github/harfbuzz/harfbuzz/release/10.4.0)). Backport is not clean because it required adapting `make/lib/Awt2dLibraries.gmk` to fit JDK11.
>> 
>> Even though the backport built correctly, the resulting `jdk/lib/libfontmanager.so` contained undefined symbols that caused Swing tests to fail with `UnsatisfiedLinkError`. This is because JDK11 is missing [JDK-8319197](https://bugs.openjdk.org/browse/JDK-8319197) that excludes hb-subset from compilation, so this is also included as the second commit in the pull request.
>> 
>> While at it, a third commit adds an additional `-Wno-attributes` flag to `HARFBUZZ_DISABLED_WARNINGS_CXX_gcc`, restoring the capability to build JDK11 on Linux with `gcc-4.8.5`  (this is an old version of gcc, dating from 2015, but it's still the system gcc version in RHEL-7).
>> 
>> Tested 
>> 
>> - on Windows 10 with `jdk:jfc_demo`. 
>> - on Linux with `jdk:jfc_demo`, with 
>>     - `gcc 4.8.5/harfbuzz-1.7.5 (x86_64 & s390x)`, 
>>     - `gcc 8.5.0/harfbuzz-1.7.5 (x86_64)`, 
>>     - `gcc 11.5.0/harfbuzz-2.7.4 (x86_64)` 
>>     - and `gcc 14.2.1/harfbuzz-9.0.0 (x86_64)`
>> 
>> with both `--with-harfbuzz=system` and `--with-harfbuzz=bundled`.
>
> Antonio Vieiro has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains nine additional commits since the last revision:
> 
>  - Merge remote-tracking branch 'upstream/master' into backports/JDK-8334964
>  - Restoring "dangling-pointer" in "HARFBUZZ_DISABLED_WARNINGS_gcc"
>  - ... and comments
>  - Removing flags for building with with GCC-4.8 and GCC-12 and up
>  - Rearrange Awt2dLibraries.gmk as per review
>  - Removed parentheses and use-after-free (tested with gcc 14 & gcc 4.8.5)
>  - Additional "attributes" flag for Linux/GCC 4.8.5
>  - Backport f4e99de33e35826ec1fb368d6ad96005d7bd5cc4
>  - Backport ba3db307dceb41e48014451873fdf4db3816a537

Let's get this in.

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Marked as reviewed by andrew (Reviewer).

PR Review: https://git.openjdk.org/jdk11u-dev/pull/3026#pullrequestreview-3161055604