Promote experimental_toolchain_generated_sysroot to non-experimental (#…

…2849)

No functional changes intended.

We've got a use case where the ability to turn this off is useful, see
(#2848 (comment)).

Closes #2298

rust/private/rustc.bzl

@@ -1068,7 +1068,7 @@ def construct_arguments(
         ))
 
     # Ensure the sysroot is set for the target platform
-    if toolchain._experimental_toolchain_generated_sysroot:
+    if toolchain._toolchain_generated_sysroot:
         rustc_flags.add(toolchain.sysroot, format = "--sysroot=%s")
 
     if toolchain._rename_first_party_crates:

rust/settings/BUILD.bazel

@@ -1,7 +1,6 @@
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 load("@bazel_skylib//rules:common_settings.bzl", "bool_flag", "string_flag")
 load("//rust/private:unpretty.bzl", "rust_unpretty_flag")
-load(":incompatible.bzl", "incompatible_flag")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -85,11 +84,10 @@ bool_flag(
     build_setting_default = True,
 )
 
-# A flag to set rustc --sysroot flag to the sysroot generated by rust_toolchain
-incompatible_flag(
-    name = "experimental_toolchain_generated_sysroot",
+# A flag to set rustc --sysroot flag to the sysroot generated by rust_toolchain.
+bool_flag(
+    name = "toolchain_generated_sysroot",
     build_setting_default = True,
-    issue = "https://github.com/bazelbuild/rules_rust/issues/2039",
 )
 
 # A flag to control whether to link libstd dynamically.

rust/toolchain.bzl

@@ -18,7 +18,6 @@ load(
     "is_std_dylib",
     "make_static_lib_symlink",
 )
-load("//rust/settings:incompatible.bzl", "IncompatibleFlagInfo")
 
 rust_analyzer_toolchain = _rust_analyzer_toolchain
 rustfmt_toolchain = _rustfmt_toolchain
@@ -697,7 +696,7 @@ def _rust_toolchain_impl(ctx):
         _experimental_use_cc_common_link = _experimental_use_cc_common_link(ctx),
         _experimental_use_global_allocator = experimental_use_global_allocator,
         _experimental_use_coverage_metadata_files = ctx.attr._experimental_use_coverage_metadata_files[BuildSettingInfo].value,
-        _experimental_toolchain_generated_sysroot = ctx.attr._experimental_toolchain_generated_sysroot[IncompatibleFlagInfo].enabled,
+        _toolchain_generated_sysroot = ctx.attr._toolchain_generated_sysroot[BuildSettingInfo].value,
         _no_std = no_std,
     )
     return [
@@ -872,13 +871,6 @@ rust_toolchain = rule(
         "_cc_toolchain": attr.label(
             default = Label("@bazel_tools//tools/cpp:current_cc_toolchain"),
         ),
-        "_experimental_toolchain_generated_sysroot": attr.label(
-            default = Label("//rust/settings:experimental_toolchain_generated_sysroot"),
-            doc = (
-                "Label to a boolean build setting that lets the rule knows wheter to set --sysroot to rustc" +
-                "This flag is only relevant when used together with --@rules_rust//rust/settings:experimental_toolchain_generated_sysroot."
-            ),
-        ),
         "_experimental_use_coverage_metadata_files": attr.label(
             default = Label("//rust/settings:experimental_use_coverage_metadata_files"),
         ),
@@ -901,6 +893,13 @@ rust_toolchain = rule(
         "_third_party_dir": attr.label(
             default = Label("//rust/settings:third_party_dir"),
         ),
+        "_toolchain_generated_sysroot": attr.label(
+            default = Label("//rust/settings:toolchain_generated_sysroot"),
+            doc = (
+                "Label to a boolean build setting that lets the rule knows wheter to set --sysroot to rustc. " +
+                "This flag is only relevant when used together with --@rules_rust//rust/settings:toolchain_generated_sysroot."
+            ),
+        ),
     },
     toolchains = [
         "@bazel_tools//tools/cpp:toolchain_type",

test/toolchain/toolchain_test.bzl

@@ -81,15 +81,15 @@ toolchain_adds_rustc_flags_lib_test = analysistest.make(
     _toolchain_adds_rustc_flags_lib_impl,
     config_settings = {
         str(Label("//:extra_rustc_flags")): [CONFIG_FLAG],
-        str(Label("//rust/settings:experimental_toolchain_generated_sysroot")): True,
+        str(Label("//rust/settings:toolchain_generated_sysroot")): True,
     },
 )
 
 toolchain_adds_rustc_flags_shared_lib_test = analysistest.make(
     _toolchain_adds_rustc_flags_shared_lib_impl,
     config_settings = {
         str(Label("//:extra_rustc_flags")): [CONFIG_FLAG],
-        str(Label("//rust/settings:experimental_toolchain_generated_sysroot")): True,
+        str(Label("//rust/settings:toolchain_generated_sysroot")): True,
     },
 )