RELNOTES: throw an error if attributes contain an absolute path instead of silently ignoring them.

Addresses https://github.com/bazelbuild/rules_cc/issues/490

PiperOrigin-RevId: 955278429
Change-Id: I92486e4f35bb355b22da2c9aedeec2d7f4213606

cc/common/cc_helper.bzl

diff --git a/cc/common/cc_helper.bzl b/cc/common/cc_helper.bzl
index 6a17c68..dc660a7 100644
--- a/cc/common/cc_helper.bzl
+++ b/cc/common/cc_helper.bzl
@@ -866,7 +866,7 @@
     for include in getattr(ctx.attr, attr):
         includes_attr = _expand(ctx, include, additional_make_variable_substitutions)
         if is_path_absolute(includes_attr):
-            continue
+            fail("The path '" + includes_attr + "' is absolute, but only relative paths are allowed.", attr = attr)
         includes_path = get_relative_path(package_exec_path, includes_attr)
         if not sibling_repository_layout and path_contains_up_level_references(includes_path):
             fail("Path references a path above the execution root.", attr = "includes")

tests/cc/common/cc_library_configured_target_tests.bzl

diff --git a/tests/cc/common/cc_library_configured_target_tests.bzl b/tests/cc/common/cc_library_configured_target_tests.bzl
index 95ad741..4b583bf 100644
--- a/tests/cc/common/cc_library_configured_target_tests.bzl
+++ b/tests/cc/common/cc_library_configured_target_tests.bzl
@@ -80,10 +80,58 @@
     target.runfiles().not_contains_predicate(matching.str_endswith(".a"))
     target.data_runfiles().not_contains_predicate(matching.str_endswith(".a"))
 
+def _test_absolute_includes_fail(name):
+    util.helper_target(
+        cc_library,
+        name = name + "_lib",
+        hdrs = ["header.h"],
+        includes = ["/absolute/path"],
+    )
+    cc_analysis_test(
+        name = name,
+        impl = _test_absolute_includes_fail_impl,
+        target = name + "_lib",
+        expect_failure = True,
+    )
+
+def _test_absolute_includes_fail_impl(env, target):
+    expected_msg = "The path '/absolute/path' is absolute, but only relative paths are allowed."
+    env.expect.that_target(target).failures().contains_predicate(
+        matching.custom(
+            "contains '{}'".format(expected_msg),
+            lambda s: expected_msg in s,
+        ),
+    )
+
+def _test_absolute_includes_windows_fail(name):
+    util.helper_target(
+        cc_library,
+        name = name + "_lib",
+        hdrs = ["header.h"],
+        includes = ["C:\\absolute\\path"],
+    )
+    cc_analysis_test(
+        name = name,
+        impl = _test_absolute_includes_windows_fail_impl,
+        target = name + "_lib",
+        expect_failure = True,
+    )
+
+def _test_absolute_includes_windows_fail_impl(env, target):
+    expected_msg = "The path 'C:\\absolute\\path' is absolute, but only relative paths are allowed."
+    env.expect.that_target(target).failures().contains_predicate(
+        matching.custom(
+            "contains '{}'".format(expected_msg),
+            lambda s: expected_msg in s,
+        ),
+    )
+
 def cc_library_configured_target_tests(name):
     test_suite(
         name = name,
         tests = [
             _test_cc_library_data_in_runfiles,
+            _test_absolute_includes_fail,
+            _test_absolute_includes_windows_fail,
         ] if bazel_features.cc.cc_common_is_in_rules_cc else [],
     )