Fill in TODOs

rust/repositories.bzl

@@ -314,7 +314,7 @@ def rust_register_toolchains(
         if extra_toolchain_infos:
             for name, info in extra_toolchain_infos.items():
                 toolchain_names.append(name)
-                toolchain_labels[name] = info["label"]
+                toolchain_labels[name] = info["tools_toolchain_label"]
                 exec_compatible_with_by_toolchain[name] = info["exec_compatible_with"]
                 target_compatible_with_by_toolchain[name] = info["target_compatible_with"]
                 toolchain_target_settings[name] = info["target_settings"]
@@ -641,7 +641,7 @@ def rust_toolchain_repository(
         auth_patterns (list, optional): A list of patterns to match against urls for which the auth object should be used.
 
     Returns:
-        str: The name of the registerable toolchain created by this rule.
+        dict[str, str]: Information about the name of the registerable toolchain created by this rule.
     """
     if exec_compatible_with == None:
         exec_compatible_with = triple_to_constraint_set(exec_triple)
@@ -673,18 +673,28 @@ def rust_toolchain_repository(
 
     channel_target_settings = ["@rules_rust//rust/toolchain/channel:{}".format(channel)] if channel else []
 
+    tools_toolchain_label = "@{}//:rust_toolchain".format(tools_repo_name)
+
+    toolchain_type = "@rules_rust//rust:toolchain"
+
     toolchain_repository_proxy(
         name = name,
-        toolchain = "@{}//:rust_toolchain".format(tools_repo_name),
+        toolchain = tools_toolchain_label,
         target_settings = channel_target_settings + target_settings,
-        toolchain_type = "@rules_rust//rust:toolchain",
+        toolchain_type = toolchain_type,
         exec_compatible_with = exec_compatible_with,
         target_compatible_with = target_compatible_with,
     )
 
-    return "@{name}//:toolchain".format(
-        name = name,
-    )
+    return {
+        "exec_compatible_with": exec_compatible_with,
+        "name": name,
+        "target_compatible_with": target_compatible_with,
+        "target_settings": target_settings,
+        "toolchain_label": "@{name}//:toolchain".format(name = name),
+        "tools_toolchain_label": tools_toolchain_label,
+        "toolchain_type": toolchain_type,
+    }
 
 _RUST_ANALYZER_TOOLCHAIN_TOOLS_REPOSITORY_ATTRS = {
     "auth": attr.string_dict(
@@ -1170,7 +1180,7 @@ def rust_repository_set(
         else:
             fail("extra_rustc_flags should be a list or a dict")
 
-        toolchain_label = rust_toolchain_repository(
+        toolchain_info = rust_toolchain_repository(
             name = toolchain.name,
             allocator_library = allocator_library,
             global_allocator_library = global_allocator_library,
@@ -1193,20 +1203,8 @@ def rust_repository_set(
             exec_compatible_with = exec_compatible_with,
             target_compatible_with = toolchain.target_constraints,
         )
-        toolchain_labels.append(toolchain_label)
-        all_toolchain_details[toolchain.name] = {
-            # TODO: Don't duplicate the defaulting here
-            "exec_compatible_with": exec_compatible_with or triple_to_constraint_set(exec_triple),
-            # "label": toolchain_label,
-            # TODO: Don't duplicate
-            "label": "@{}_tools//:rust_toolchain".format(toolchain.name),
-            "name": toolchain.name,
-            # TODO: Don't duplicate the defaulting here
-            "target_compatible_with": toolchain.target_constraints or triple_to_constraint_set(toolchain.target_triple),
-            "target_settings": target_settings,
-            # TODO: Don't duplicate
-            "toolchain_type": "@rules_rust//rust:toolchain",
-        }
+        toolchain_labels.append(toolchain_info["toolchain_label"])
+        all_toolchain_details[toolchain.name] = toolchain_info
 
     # This repository exists to allow `rust_repository_set` to work with the `maybe` wrapper.
     rust_toolchain_set_repository(