Add support for flags to build on iOS

[carson-katri]

This enables v8 to be cross compiled for iOS.

OS=ios can be set in the environment before running make build-v8, and the correct extra args will be added.

[bcardarella]

Are we going to require additional flags for all of the Apple operating systems? Then also for Android, Windows, etc... ?

In other words, is adding each one by one the best approach or is there a more flexible one we should consider?

[carson-katri]

The OS can be set to anything. I'm unsure what EXTRA_ARGS would be required for other platforms. It could be adjusted so EXTRA_ARGS is pulled from the environment if present too.

[krichprollsch]

Something is wrong: I'm testing this branch against our current release build, but it doesn't work.

See https://github.com/lightpanda-io/zig-v8-fork/actions/runs/17858246544/job/50782218176?pr=97

downloading https://chrome-infra-packages.appspot.com/dl/gn/gn/macos-arm64/+/latest into tools/gn.zip
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed

  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100    35  100    35    0     0    269      0 --:--:-- --:--:-- --:--:--   271
  End-of-central-directory signature not found.  Either this file is not
  a zipfile, or it constitutes one disk of a multi-part archive.  In the
  latter case the central directory and zipfile comment will be found on
  the last disk(s) of this archive.
unzip:  cannot find zipfile directory in one of tools/gn.zip or
        tools/gn.zip.zip, and cannot find tools/gn.zip.ZIP, period.
Archive:  tools/gn.zip
get-v8
+- run exe get-v8
   +- compile exe get-v8 Debug native
      +- run /bin/bash
         +- run /bin/bash failure
error: the following command exited with error code 9:
cd v8 && /bin/bash get_tools.sh

Build Summary: 2/7 steps succeeded; 1 failed
get-v8 transitive failure
+- run exe get-v8 transitive failure
   +- compile exe get-v8 Debug native transitive failure
      +- run /bin/bash transitive failure
         +- run /bin/bash failure

error: the following build command failed with exit code 1:
/Users/runner/.cache/zig/o/41b2e58e23f54e6061b8f9707a8d50e3/build /Users/runner/work/_temp/783d9ed5-a004-4bfc-9cbe-2be4b29959e1/zig-aarch64-macos-0.15.1/zig /Users/runner/work/_temp/783d9ed5-a004-4bfc-9cbe-2be4b29959e1/zig-aarch64-macos-0.15.1/lib /Users/runner/work/zig-v8-fork/zig-v8-fork /Users/runner/.cache/zig /Users/runner/.cache/zig --seed 0xf79dda71 -Z6f21bfb0cd071259 get-v8
Error: Process completed with exit code 1.

[krichprollsch]

In fact I'm not sure it relates to your PR 🤔

[bcardarella]

Unfortunately Carson is out for the next two weeks. I can have Isaac take a look but likely it may need to wait as Carson is the Swift expert on our team

[krichprollsch]

Unfortunately Carson is out for the next two weeks. I can have Isaac take a look but likely it may need to wait as Carson is the Swift expert on our team

not a problem, we can wait until Carson is back 👍

[krichprollsch]

ok I got what's wrong: we set the OS w/ macos. I worked before b/c the OS was ignored until this change.

Suggested change

	unset)
	macos) OS="mac" ;;
	unset)

[krichprollsch]

So the zig build get-v8 is working now, but when trying to build an ios version on a macos ci server, it fails.
I suppose we need something more than jsut macos to make it work?
I would like to have a building script working for ios is possible to ensure we don't break it in the future.

ERROR at //build/config/apple/mobile_config.gni:103:3: Assertion failed.
  assert(filter_include([ target_environment ], _target_environments) != [],
  ^-----
target_environment must be in ["simulator", "device", "catalyst"]: 
See //build/config/ios/ios_sdk.gni:5:1: whence it was imported.
import("//build/config/apple/mobile_config.gni")
build-v8
^----------------------------------------------
+- run exe build-v8
See //build/toolchain/ios/BUILD.gn:5:1: whence it was imported.
   +- compile exe build-v8 ReleaseSafe native
import("//build/config/ios/ios_sdk.gni")
      +- run /bin/bash failure
^--------------------------------------
error: the following command exited with error code 1:
See //build/config/BUILDCONFIG.gn:573:5: which caused the file to be included.
cd v8 && /bin/bash build_v8.sh /Users/runner/work/zig-v8-fork/zig-v8-fork/src release

Build Summary: 0/4 steps succeeded; 1 failed
build-v8 transitive failure
+- run exe build-v8 transitive failure
   +- compile exe build-v8 ReleaseSafe native transitive failure
      +- run /bin/bash failure

error: the following build command failed with exit code 1:
/Users/runner/.cache/zig/o/41b2e58e23f54e6061b8f9707a8d50e3/build /Users/runner/work/_temp/e2f12e67-622e-45a3-8e27-5b11f7a2ac49/zig-aarch64-macos-0.15.1/zig /Users/runner/work/_temp/e2f12e67-622e-45a3-8e27-5b11f7a2ac49/zig-aarch64-macos-0.15.1/lib /Users/runner/work/zig-v8-fork/zig-v8-fork /Users/runner/.cache/zig /Users/runner/.cache/zig --seed 0x471b6248 -Z5e0cefb92602fdf8 -Doptimize=ReleaseSafe build-v8
    target(_target_type, target_name) {
    ^----------------------------------
Error: Process completed with exit code 1.

Here is the log: https://github.com/lightpanda-io/zig-v8-fork/actions/runs/17859485614/job/50786267288
Here is the the ci script I'm using:

zig-v8-fork/.github/workflows/build-release.yml

Lines 144 to 172 in 8589ee0

	build-aarch64-ios:
	env:
	OS: ios
	ARCH: aarch64
	runs-on: macos-latest
	steps:
	- uses: mlugg/setup-zig@v2
	with:
	version: ${{ env.ZIG_VERSION }}
	- uses: actions/setup-python@v5
	with:
	python-version: '3.11'
	- uses: actions/checkout@v4
	with:
	submodules: recursive
	fetch-depth: 0
	- run: OS=macos zig build get-v8 # We force the OS to macos here b/c ios is not supported by get-v8
	- run: zig build -Doptimize=ReleaseSafe build-v8
	- run: mv v8/out/${{ env.OS }}/release/obj/zig/libc_v8.a libc_v8_${{ env.V8_REVISION }}_${{ env.OS }}_${{ env.ARCH }}.a
	- name: Upload the build
	uses: ncipollo/release-action@v1
	with:
	allowUpdates: true
	artifacts: libc_v8_${{ env.V8_REVISION }}_${{ env.OS }}_${{ env.ARCH }}.a

(similar to macos instead setting OS=ios.