Get toolchain working

examples/rule_based_toolchain/MODULE.bazel

@@ -3,8 +3,9 @@ module(
     version = "0.0.1",
 )
 
+bazel_dep(name = "platforms", version = "0.0.10")
 bazel_dep(name = "googletest", version = "1.15.2")
-bazel_dep(name = "skylib", version = "1.7.1")
+bazel_dep(name = "bazel_skylib", version = "1.7.1")
 
 bazel_dep(name = "rules_cc")
 local_path_override(module_name = "rules_cc", path = "../..")
@@ -28,8 +29,6 @@ http_archive(
 )
 
 register_toolchains(
-    [
-        "//toolchain:host-linux-x86_64",
-    ],
+    "//toolchain:host-linux-x86_64",
     dev_dependency = True,
 )

examples/rule_based_toolchain/dynamic_answer/dynamic_answer.c

@@ -1,5 +1,5 @@
 #include "dynamic_answer.h"
 
-int dynamic_answer() {
+int dynamic_answer(void) {
     return 24;
 }

examples/rule_based_toolchain/toolchain/BUILD

@@ -15,7 +15,7 @@ cc_args(
     actions = [
         "@rules_cc//cc/toolchains/actions:c_compile",
         "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
-    ]
+    ],
     args = [
         "-Wall",
         "-Wextra",
@@ -23,18 +23,28 @@ cc_args(
     ],
 )
 
+cc_args(
+    name = "no_canonical_prefixes",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+    ],
+    args = ["-no-canonical-prefixes"],
+)
+
 [
     cc_toolchain(
-        name = "host-{}-config".format(platform),
+        name = "host-{}-config".format(platform_name),
         args = select({
             "@platforms//os:linux": [
                 "@linux_sysroot//:sysroot",
             ],
             "//conditions:default": [],
         }) + [
+            ":no_canonical_prefixes",
             ":warnings",
         ],
-        tools = "@clang-{}//:all_tools".format(platform),
+        tool_map = "@clang-{}//:all_tools".format(platform_name),
         known_features = ["@rules_cc//cc/toolchains/args:experimental_replace_legacy_action_config_features"],
         enabled_features = ["@rules_cc//cc/toolchains/args:experimental_replace_legacy_action_config_features"],
         target_compatible_with = constraints,
@@ -44,10 +54,11 @@ cc_args(
 
 [
     toolchain(
-        name = "host-{}".format(platform),
+        name = "host-{}".format(platform_name),
         exec_compatible_with = constraints,
         target_compatible_with = constraints,
+        toolchain = ":host-{}-config".format(platform_name),
+        toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
     )
-    toolchain = ":host_toolchain",
-    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+    for platform_name, constraints in PLATFORMS.items()
 ]

examples/rule_based_toolchain/toolchain/linux_sysroot.BUILD

@@ -8,8 +8,7 @@ cc_sysroot(
     name = "sysroot",
     sysroot = ":root",
     data = [":root"],
-    implicit_include_directories = [
-        ":usr-local-include",
+    allowlist_include_directories = [
         ":usr-include-x86_64-linux-gnu",
         ":usr-include",
     ],
@@ -20,17 +19,14 @@ directory(
     srcs = glob(["**/*"]),
 )
 
-subdirectory(
-    name = "usr-local-include",
-    path = "usr/local/include",
-)
-
 subdirectory(
     name = "usr-include-x86_64-linux-gnu",
     path = "usr/include/x86_64-linux-gnu",
+    parent = ":root",
 )
 
 subdirectory(
     name = "usr-include",
     path = "usr/include",
+    parent = ":root",
 )