Bind Dylint checks to named Rust toolchain families

Dylint requires its checked graph, lint libraries, and driver to agree on the same nightly compiler family. Model that family explicitly so rust_dylint can select an exact generated rules_rs toolchain repo rather than any registered nightly toolchain.\n\nKeep ordinary toolchain resolution unchanged when no family is requested, and make dylint_toolchain declare the matching Bazel toolchain wrapper for users.\n\nCo-authored-by: Codex <noreply@openai.com>

Author: andyscott

docs/dylint.md

@@ -46,12 +46,18 @@ def _dylint_transition_impl(_settings, _attr):
     # its dependency metadata stays compatible with the compiler that runs the
     # lints. Transition only the explicit Dylint subtree; ordinary Rust builds
     # keep using the caller's regular toolchain selection.
-    return {"@rules_rust//rust/toolchain/channel:channel": "nightly"}
+    return {
+        "@rules_rust//rust/toolchain/channel:channel": "nightly",
+        "@rules_rs//rs/toolchains/family:family": _attr.toolchain_family,
+    }
 
 _dylint_transition = transition(
     implementation = _dylint_transition_impl,
     inputs = [],
-    outputs = ["@rules_rust//rust/toolchain/channel:channel"],
+    outputs = [
+        "@rules_rust//rust/toolchain/channel:channel",
+        "@rules_rs//rs/toolchains/family:family",
+    ],
 )
 
 def _empty_lints_info():
@@ -154,7 +160,7 @@ def _dylint_toolchain_impl(ctx):
         ),
     ]
 
-dylint_toolchain = rule(
+_dylint_toolchain = rule(
     implementation = _dylint_toolchain_impl,
     attrs = {
         "driver": attr.label(
@@ -167,6 +173,56 @@ dylint_toolchain = rule(
     doc = "Defines the host-side dylint-driver executable used by `rust_dylint`.",
 )
 
+def dylint_toolchain(
+        name,
+        *,
+        driver,
+        toolchain_family,
+        exec_compatible_with = [],
+        target_compatible_with = [],
+        visibility = None,
+        tags = []):
+    """Declares one Dylint driver toolchain bound to a Rust toolchain family.
+
+    `toolchain_family` must match the `name` of the `toolchains.toolchain(...)`
+    tag that provisions the nightly Rust toolchains this driver was built with.
+    """
+
+    if not toolchain_family:
+        fail("`toolchain_family` must name the nightly rules_rs toolchain family used by this Dylint driver")
+
+    impl_name = name + "_impl"
+    family_setting_name = name + "_family"
+
+    _dylint_toolchain(
+        name = impl_name,
+        driver = driver,
+        tags = tags,
+        visibility = ["//visibility:private"],
+    )
+
+    native.config_setting(
+        name = family_setting_name,
+        flag_values = {
+            "@rules_rs//rs/toolchains/family:family": toolchain_family,
+        },
+        visibility = ["//visibility:private"],
+    )
+
+    toolchain_kwargs = dict(
+        name = name,
+        exec_compatible_with = exec_compatible_with,
+        target_compatible_with = target_compatible_with,
+        target_settings = [":" + family_setting_name],
+        toolchain = ":" + impl_name,
+        toolchain_type = "@rules_rs//rs/dylint:toolchain_type",
+        tags = tags,
+    )
+    if visibility != None:
+        toolchain_kwargs["visibility"] = visibility
+
+    native.toolchain(**toolchain_kwargs)
+
 def _crate_info(target):
     if rust_common.crate_info in target:
         return target[rust_common.crate_info]
@@ -372,6 +428,10 @@ rust_dylint = rule(
             ],
             aspects = [rust_dylint_aspect],
         ),
+        "toolchain_family": attr.string(
+            doc = "Name of the nightly rules_rs toolchain family used for this Dylint check.",
+            mandatory = True,
+        ),
         "_allowlist_function_transition": attr.label(
             default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
         ),

rs/private/dylint.bzl

@@ -6,23 +6,33 @@ load("@rules_rs//rs/toolchains:declare_rust_analyzer_toolchains.bzl", "declare_r
 load("@rules_rs//rs/toolchains:declare_rustc_toolchains.bzl", "declare_rustc_toolchains")
 load("@rules_rs//rs/toolchains:declare_rustfmt_toolchains.bzl", "declare_rustfmt_toolchains")
 
+config_setting(
+    name = "selected_family",
+    flag_values = {{
+        "@rules_rs//rs/toolchains/family:family": {toolchain_family},
+    }},
+)
+
 declare_rustc_toolchains(
     version = {version},
     edition = {edition},
     include_rustc_dev = {include_rustc_dev},
     extra_rustc_flags = {extra_rustc_flags},
     extra_exec_rustc_flags = {extra_exec_rustc_flags},
+    toolchain_family_setting = ":selected_family",
 )
 
 declare_rustfmt_toolchains(
     version = {version},
     rustfmt_version = {rustfmt_version},
     edition = {edition},
+    toolchain_family_setting = ":selected_family",
 )
 
 declare_rust_analyzer_toolchains(
     version = {version},
     rust_analyzer_version = {rust_analyzer_version},
+    toolchain_family_setting = ":selected_family",
 )
 """.format(
             version = repr(rctx.attr.version),
@@ -32,6 +42,7 @@ declare_rust_analyzer_toolchains(
             include_rustc_dev = repr(rctx.attr.include_rustc_dev),
             extra_rustc_flags = repr(rctx.attr.extra_rustc_flags),
             extra_exec_rustc_flags = repr(rctx.attr.extra_exec_rustc_flags),
+            toolchain_family = repr(rctx.attr.toolchain_family),
         ),
     )
 
@@ -47,5 +58,6 @@ toolchains_repository = repository_rule(
         "include_rustc_dev": attr.bool(),
         "extra_rustc_flags": attr.string_list_dict(),
         "extra_exec_rustc_flags": attr.string_list_dict(),
+        "toolchain_family": attr.string(mandatory = True),
     },
 )

rs/private/toolchains_repository.bzl

@@ -23,6 +23,7 @@ def declare_rust_analyzer_toolchains(
         *,
         version,
         rust_analyzer_version,
+        toolchain_family_setting = None,
         execs = SUPPORTED_EXEC_TRIPLES):
     version_key = sanitize_version(version)
     rust_analyzer_version_key = sanitize_version(rust_analyzer_version)
@@ -56,17 +57,38 @@ def declare_rust_analyzer_toolchains(
 
         rust_analyzer_toolchain(**rust_analyzer_toolchain_kwargs)
 
+        target_settings = [
+            "@rules_rust//rust/toolchain/channel:" + channel,
+        ]
+        if toolchain_family_setting != None:
+            target_settings.append("@rules_rs//rs/toolchains/family:unspecified")
+
         native.toolchain(
             name = "{}_{}_rust_analyzer_{}".format(exec_triple.system, exec_triple.arch, version_key),
             exec_compatible_with = [
                 "@platforms//os:" + exec_triple.system,
                 "@platforms//cpu:" + exec_triple.arch,
             ],
             target_compatible_with = [],
-            target_settings = [
-                "@rules_rust//rust/toolchain/channel:" + channel,
-            ],
+            target_settings = target_settings,
             toolchain = rust_analyzer_toolchain_name,
             toolchain_type = "@rules_rust//rust/rust_analyzer:toolchain_type",
             visibility = ["//visibility:public"],
         )
+
+        if toolchain_family_setting != None:
+            native.toolchain(
+                name = "{}_{}_rust_analyzer_{}_selected_family".format(exec_triple.system, exec_triple.arch, version_key),
+                exec_compatible_with = [
+                    "@platforms//os:" + exec_triple.system,
+                    "@platforms//cpu:" + exec_triple.arch,
+                ],
+                target_compatible_with = [],
+                target_settings = [
+                    "@rules_rust//rust/toolchain/channel:" + channel,
+                    toolchain_family_setting,
+                ],
+                toolchain = rust_analyzer_toolchain_name,
+                toolchain_type = "@rules_rust//rust/rust_analyzer:toolchain_type",
+                visibility = ["//visibility:public"],
+            )

rs/toolchains/declare_rust_analyzer_toolchains.bzl

@@ -23,6 +23,7 @@ def declare_rustc_toolchains(
         include_rustc_dev = False,
         extra_rustc_flags = {},
         extra_exec_rustc_flags = {},
+        toolchain_family_setting = None,
         execs = SUPPORTED_EXEC_TRIPLES,
         targets = SUPPORTED_TARGET_TRIPLES):
     """Declare toolchains for all supported target platforms."""
@@ -141,6 +142,17 @@ def declare_rustc_toolchains(
 
         for target_triple in targets:
             target_key = sanitize_triple(target_triple)
+            bootstrapped_target_settings = [
+                "@rules_rust//rust/private:bootstrapped",
+                "@rules_rust//rust/toolchain/channel:" + channel,
+            ]
+            bootstrapping_target_settings = [
+                "@rules_rust//rust/private:bootstrapping",
+                "@rules_rust//rust/toolchain/channel:" + channel,
+            ]
+            if toolchain_family_setting != None:
+                bootstrapped_target_settings.append("@rules_rs//rs/toolchains/family:unspecified")
+                bootstrapping_target_settings.append("@rules_rs//rs/toolchains/family:unspecified")
 
             native.toolchain(
                 name = "{}_{}_to_{}_{}".format(exec_triple.system, exec_triple.arch, target_key, version_key),
@@ -149,10 +161,7 @@ def declare_rustc_toolchains(
                     "@platforms//cpu:" + exec_triple.arch,
                 ],
                 target_compatible_with = triple_to_constraint_set(target_triple),
-                target_settings = [
-                    "@rules_rust//rust/private:bootstrapped",
-                    "@rules_rust//rust/toolchain/channel:" + channel,
-                ],
+                target_settings = bootstrapped_target_settings,
                 toolchain = rust_toolchain_name,
                 toolchain_type = "@rules_rust//rust:toolchain_type",
                 visibility = ["//visibility:public"],
@@ -165,11 +174,43 @@ def declare_rustc_toolchains(
                     "@platforms//cpu:" + exec_triple.arch,
                 ],
                 target_compatible_with = triple_to_constraint_set(target_triple),
-                target_settings = [
-                    "@rules_rust//rust/private:bootstrapping",
-                    "@rules_rust//rust/toolchain/channel:" + channel,
-                ],
+                target_settings = bootstrapping_target_settings,
                 toolchain = rust_toolchain_name + "_bootstrap",
                 toolchain_type = "@rules_rust//rust:toolchain_type",
                 visibility = ["//visibility:public"],
             )
+
+            if toolchain_family_setting != None:
+                native.toolchain(
+                    name = "{}_{}_to_{}_{}_selected_family".format(exec_triple.system, exec_triple.arch, target_key, version_key),
+                    exec_compatible_with = [
+                        "@platforms//os:" + exec_triple.system,
+                        "@platforms//cpu:" + exec_triple.arch,
+                    ],
+                    target_compatible_with = triple_to_constraint_set(target_triple),
+                    target_settings = [
+                        "@rules_rust//rust/private:bootstrapped",
+                        "@rules_rust//rust/toolchain/channel:" + channel,
+                        toolchain_family_setting,
+                    ],
+                    toolchain = rust_toolchain_name,
+                    toolchain_type = "@rules_rust//rust:toolchain_type",
+                    visibility = ["//visibility:public"],
+                )
+
+                native.toolchain(
+                    name = "{}_{}_to_{}_{}_bootstrap_selected_family".format(exec_triple.system, exec_triple.arch, target_key, version_key),
+                    exec_compatible_with = [
+                        "@platforms//os:" + exec_triple.system,
+                        "@platforms//cpu:" + exec_triple.arch,
+                    ],
+                    target_compatible_with = triple_to_constraint_set(target_triple),
+                    target_settings = [
+                        "@rules_rust//rust/private:bootstrapping",
+                        "@rules_rust//rust/toolchain/channel:" + channel,
+                        toolchain_family_setting,
+                    ],
+                    toolchain = rust_toolchain_name + "_bootstrap",
+                    toolchain_type = "@rules_rust//rust:toolchain_type",
+                    visibility = ["//visibility:public"],
+                )

rs/toolchains/declare_rustc_toolchains.bzl

@@ -15,6 +15,7 @@ def declare_rustfmt_toolchains(
         version,
         rustfmt_version,
         edition,
+        toolchain_family_setting = None,
         execs = SUPPORTED_EXEC_TRIPLES):
     version_key = sanitize_version(version)
     rustfmt_version_key = sanitize_version(rustfmt_version)
@@ -42,17 +43,38 @@ def declare_rustfmt_toolchains(
             tags = ["rust_version={}".format(version)],
         )
 
+        target_settings = [
+            "@rules_rust//rust/toolchain/channel:" + channel,
+        ]
+        if toolchain_family_setting != None:
+            target_settings.append("@rules_rs//rs/toolchains/family:unspecified")
+
         native.toolchain(
             name = "{}_{}_rustfmt_{}".format(exec_triple.system, exec_triple.arch, version_key),
             exec_compatible_with = [
                 "@platforms//os:" + exec_triple.system,
                 "@platforms//cpu:" + exec_triple.arch,
             ],
             target_compatible_with = [],
-            target_settings = [
-                "@rules_rust//rust/toolchain/channel:" + channel,
-            ],
+            target_settings = target_settings,
             toolchain = rustfmt_toolchain_name,
             toolchain_type = "@rules_rust//rust/rustfmt:toolchain_type",
             visibility = ["//visibility:public"],
         )
+
+        if toolchain_family_setting != None:
+            native.toolchain(
+                name = "{}_{}_rustfmt_{}_selected_family".format(exec_triple.system, exec_triple.arch, version_key),
+                exec_compatible_with = [
+                    "@platforms//os:" + exec_triple.system,
+                    "@platforms//cpu:" + exec_triple.arch,
+                ],
+                target_compatible_with = [],
+                target_settings = [
+                    "@rules_rust//rust/toolchain/channel:" + channel,
+                    toolchain_family_setting,
+                ],
+                toolchain = rustfmt_toolchain_name,
+                toolchain_type = "@rules_rust//rust/rustfmt:toolchain_type",
+                visibility = ["//visibility:public"],
+            )