Add --incompatible_disable_objc_library_transition

[keith]

This is a migration for #16870

Users who rely on the current behavior should instead wrap their library in a target from rules_apple.

Fixes #19204

[cpsauer]

Can confirm that, when flipped, this leads to clean builds both under rules_apple and under cc_binary in our teams repo's fairly large set of cc <-> objc interoperability cases, fixing #19204. Thanks, Keith!
(For any others: Was testing by splicing in Bazel's //src and passing --experimental_builtins_bzl_path="%workspace%")

To ease the migration, might you at some point also want some of the test changes from #19236, easing assumptions on under-configured sets of internal flags?

[googlewalt]

Can we add a test for the flag?

[keith]

FYI @comius since it looks like you're working in this area too with 03b8616

[comius]

Nice, thanks!

I was also looking into removing this transition. It needs some depo fixes, but not a lot of them. So once this is merges, I can look into flipping the default value.

[keith]

Added a quick test!

[erneestoc]

I hit a related issue yesterday! Thank you 🙏🏻

[brentleyjones]

@bazelbuild/triage Is this being manually imported or does it need the label?

[iancha1992]

@brentleyjones @comius @buildbreaker2021 if this needs to be merged to the master, then please add the label, "awaiting-PR-merge". We'll handle it afterwards. Thanks!

[googlewalt]

Unfortunately, I don't have the ability to add labels.

[brentleyjones]

Based on your comment I just changed them. Thanks @googlewalt!

[brentleyjones]

@bazel-io flag

[iancha1992]

@bazel-io fork 6.4.0

[iancha1992]

@comius @cpsauer @keith @googlewalt @buildbreaker2021 @brentleyjones
We've tried to cherry-pick this to release-6.4.0 branch, but looks like there are some conflicts.

1. src/main/java/com/google/devtools/build/lib/packages/semantics/BuildLanguageOptions.java

public static final String EXPERIMENTAL_GET_FIXED_CONFIGURED_ACTION_ENV =
      "-experimental_get_fixed_configured_action_env";

should be removed from the release-6.4.0 branch before cherry-picking

2. src/main/java/com/google/devtools/build/lib/packages/semantics/BuildLanguageOptions.java

.setBool(
                EXPERIMENTAL_GET_FIXED_CONFIGURED_ACTION_ENV,
                experimentalGetFixedConfiguredEnvironment)

before the cherry-picking, the release branch should have above removed and instead have below:

.setBool(
                INCOMPATIBLE_MERGE_FIXED_AND_DEFAULT_SHELL_ENV,
                incompatibleMergeFixedAndDefaultShellEnv)
            .setBool(
                INCOMPATIBLE_OBJC_PROVIDER_REMOVE_LINKING_INFO,
                incompatibleObjcProviderRemoveLinkingInfo)

3. src/main/java/com/google/devtools/build/lib/rules/cpp/CcModule.java
   public void checkExperimentalStarlarkCcImport function should be removed from the release-6.4.0 branch before cherry-picking

4. src/main/java/com/google/devtools/build/lib/starlarkbuildapi/cpp/CcModuleApi.java

@StarlarkMethod(
      name = "check_experimental_starlark_cc_import",
      doc = "DO NOT USE. This is to guard use of cc_import.bzl",
      documented = false,
      parameters = {
        @Param(
            name = "actions",
            positional = false,
            named = true,
            doc = "<code>actions</code> object."),
      })

should be removed from the release branch before cherry-picking

5. src/main/starlark/builtins_bzl/common/cc/cc_common.bzl
   The file isn't in the release branch. It should be added to the release branch before cherry-picking.

load(":common/cc/cc_info.bzl", "CcInfo")

,

load("@_builtins//:common/objc/semantics.bzl", "semantics")

,

load("@_builtins//:common/objc/objc_common.bzl", "extensions", "objc_common")

should be added to the release branch before cherry-picking

cc: @bazelbuild/triage

[keith]

#19393

[iancha1992]

The changes in this PR have been included in Bazel 6.4.0 RC1. Please test out the release candidate and report any issues as soon as possible. If you're using Bazelisk, you can point to the latest RC by setting USE_BAZEL_VERSION=last_rc.
Thanks!