Add feature injection

Add feature injection to toolchain gcc extension. This option will
allow users to add external defined features.

Author: nradakovic

docs/examples_and_validation.md

@@ -45,7 +45,8 @@ platforms.
 `examples/BUILD`
 
 Contains small C++ targets used to verify compilation, linking, pthread
-support, and sanitizer integration.
+support, and optional sanitizer integration when sanitizer features are
+registered explicitly.
 
 `examples/test.sh`
 
@@ -85,4 +86,12 @@ In practice this means checking among other things:
 - correct toolchain registration and platform matching,
 - basic linking behavior,
 - feature coverage such as pthread-enabled builds,
-- optional sanitizer feature wiring for the local Linux toolchain path.
+- optional sanitizer feature wiring for the local Linux toolchain path.
+
+## Sanitizer Note
+
+Sanitizer features are not included by default by the generated toolchains.
+If a workspace wants to use targets such as `asan_test`, it must first
+register the sanitizer `cc_feature` definitions explicitly, for example via
+`extra_known_features` or `extra_enabled_features` when declaring the
+toolchain and by providing the feature definitions from `score_cpp_policies`.

docs/extension_api.md

@@ -72,6 +72,8 @@ Flag and runtime attributes:
 - `extra_c_compile_flags`
 - `extra_cxx_compile_flags`
 - `extra_link_flags`
+- `extra_known_features`
+- `extra_enabled_features`
 - `ld_library_paths`
 - `runtime_ecosystem`
 - `use_base_constraints_only`
@@ -112,5 +114,9 @@ configurations for this activation step.
 - The extension is intended for the root module.
 - When `use_default_package` is enabled, the version matrix can inject extra
   include and link flags required by non-standard sysroot layouts.
+- Sanitizer features are not registered automatically. Workspaces that want
+  sanitizer support must provide the relevant rule-based `cc_feature`
+  definitions explicitly, typically from `score_cpp_policies`, through
+  `extra_known_features` or `extra_enabled_features`.
 - QNX toolchains use additional licensing and include-path parameters that do
   not apply to Linux toolchains.

examples/BUILD

@@ -51,57 +51,3 @@ cc_test(
     linkstatic = False,
     deps = [":math_lib"],
 )
-
-cc_test(
-    name = "asan_test",
-    srcs = ["asan_test.cpp"],
-    features = ["asan"],
-    deps = [
-        "@googletest//:gtest",
-        "@googletest//:gtest_main",
-    ],
-)
-
-# for some reason this test is very flaky.
-# cc_test(
-#     name = "tsan_test",
-#     srcs = ["tsan_test.cpp"],
-#     features = ["tsan"],
-#     env = {
-#         "TSAN_OPTIONS": "halt_on_error=1",
-#     },
-#     deps = [
-#         "@googletest//:gtest",
-#         "@googletest//:gtest_main",
-#     ],
-# )
-
-cc_test(
-    name = "ubsan_test",
-    srcs = ["ubsan_test.cpp"],
-    env = {
-        "UBSAN_OPTIONS": "halt_on_error=1",
-    },
-    features = ["ubsan"],
-    deps = [
-        "@googletest//:gtest",
-        "@googletest//:gtest_main",
-    ],
-)
-
-cc_test(
-    name = "lsan_test",
-    srcs = ["lsan_test.cpp"],
-    env = {
-        "ASAN_OPTIONS": "detect_leaks=1",
-        "LSAN_OPTIONS": "exitcode=23",
-    },
-    features = [
-        "lsan",
-        "asan",
-    ],
-    deps = [
-        "@googletest//:gtest",
-        "@googletest//:gtest_main",
-    ],
-)

examples/MODULE.bazel

@@ -30,7 +30,7 @@ bazel_dep(name = "score_bazel_platforms", version = "0.1.2")
 # *******************************************************************************
 # C++ Rules for Bazel
 # *******************************************************************************
-bazel_dep(name = "rules_cc", version = "0.2.14")
+bazel_dep(name = "rules_cc", version = "0.2.17")
 bazel_dep(name = "googletest", version = "1.17.0")
 
 # *******************************************************************************

examples/MODULE.bazel.lock

@@ -10,6 +10,17 @@ The toolchain configurations are defined in:
 
 ## Building Targets
 
+## Sanitizer Feature Registration
+
+Sanitizer features are no longer included by default by the example toolchain
+declarations. Targets that request features such as `score_asan` require the
+workspace to register those feature definitions explicitly, for example from
+`score_cpp_policies` via `extra_known_features` or `extra_enabled_features` on
+the corresponding `gcc.toolchain(...)` declaration.
+
+Without that explicit registration, sanitizer-specific example targets are not
+expected to build.
+
 ### Default Toolchain
 
 Build a specific target with the default toolchain:

examples/README.md

@@ -68,6 +68,24 @@ _attrs_tc = {
         default = [],
         doc = "List of additional flags to be passed to linker.",
     ),
+    "extra_enabled_features": attr.label_list(
+        mandatory = False,
+        doc = ("Extra `cc_feature` features to add to this toolchain in an initially " +
+               "enabled state. This attribute has limited integration with `cc_feature`, " +
+               "and does not run additional correctness checks or handle things like `data` " +
+               "files. This is only offered as a migration bridge for projects transitioning " +
+               "to rule-based toolchain configurations, or sharing of simple argument sets " +
+               "with older toolchains."),
+    ),
+    "extra_known_features": attr.label_list(
+        mandatory = False,
+        doc = ("Extra `cc_feature` features to add to this toolchain in an initially " +
+               "disabled state. This attribute has limited integration with `cc_feature`, " +
+               "and does not run additional correctness checks or handle things like `data` " +
+               "files. This is only offered as a migration bridge for projects transitioning " +
+               "to rule-based toolchain configurations, or sharing of simple argument sets " +
+               "with older toolchains."),
+    ),
     "license_info_url": attr.string(
         default = "",
         mandatory = False,
@@ -193,6 +211,8 @@ def _get_toolchains(tags):
             "tc_extra_compile_flags": tag.extra_compile_flags,
             "tc_extra_cxx_compile_flags": tag.extra_cxx_compile_flags,
             "tc_extra_link_flags": tag.extra_link_flags,
+            "tc_extra_known_features": tag.extra_known_features,
+            "tc_extra_enabled_features": tag.extra_enabled_features,
             "tc_license_info_url": tag.license_info_url,
             "tc_license_info_variable": tag.license_info_variable,
             "tc_license_path": tag.license_path,
@@ -333,6 +353,8 @@ def _impl(mctx):
             extra_compile_flags = toolchain_info["tc_extra_compile_flags"],
             extra_c_compile_flags = toolchain_info["tc_extra_c_compile_flags"],
             extra_cxx_compile_flags = toolchain_info["tc_extra_cxx_compile_flags"],
+            extra_known_features = toolchain_info["tc_extra_known_features"],
+            extra_enabled_features = toolchain_info["tc_extra_enabled_features"],
             extra_link_flags = toolchain_info["tc_extra_link_flags"],
             license_info_variable = toolchain_info["tc_license_info_variable"],
             license_info_value = toolchain_info["tc_license_info_url"],