[WIP] These changes allow to build a minimal hotspot for iOS

[johanvos]

This WIP PR allows to build the hotspot minimal variant for iOS. There is an interesting PR for upstream openjdk/jdk which contains useful parts (e.g. a function lookup): https://github.com/openjdk/jdk/pull/20837 I took the liberty to use parts of that PR in this PR. If the upstream PR got merged, it should be relatively easy to merge this in openjdk/mobile.

To build the minimal hotspot for iOS, use a configuration like this one:

sh configure \
--disable-warnings-as-errors \
--openjdk-target=aarch64-macos-ios \
--with-build-jdk=/opt/jdk-24.jdk/Contents/Home \
--with-boot-jdk=/opt/jdk-24.jdk/Contents/Home \
--with-jvm-variants=minimal \
--with-sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk \
--with-cups-include=../support/cups-2.3.6

Then build it:

cd build/ios-aarch64-minimal-release
make hotspot-minimal

---

Progress

• [ ] Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• [ ] Change must not contain extraneous whitespace
• [ ] Commit message must refer to an issue

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/mobile.git pull/30/head:pull/30
$ git checkout pull/30

Update a local copy of the PR:
$ git checkout pull/30
$ git pull https://git.openjdk.org/mobile.git pull/30/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 30

View PR using the GUI difftool:
$ git pr show -t 30

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/mobile/pull/30.diff

[bridgekeeper[bot]]

:wave: Welcome back jvos! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk[bot]]

❗ This change is not yet ready to be integrated. See the Progress checklist in the description for automated requirements.

[bridgekeeper[bot]]

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[johanvos]

keep alive

[openjdk[bot]]

@johanvos this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout ios-minimal-vm
git fetch https://git.openjdk.org/mobile.git master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

[johanvos]

Obsoleted bt https://github.com/openjdk/mobile/pull/32