Address review: test parent-sink warning-level inheritance; document -Wpedantic staging in help string

Author: expipiplus1

docs/command-line-slangc-reference.md

@@ -263,7 +263,7 @@ Disable specific warning ids.
 
 **-Wall | -Wextra | -Wpedantic**
 
-Enable the corresponding group of opt-in warnings (additive). 
+Enable the corresponding group of opt-in warnings (additive). Staging: the pedantic group is currently enabled by default, so [-Wpedantic](#wall-1) is a no-op today; a future release will make it opt-in. 
 
 
 <a id="w"></a>

source/slang/slang-options.cpp

@@ -588,7 +588,9 @@ void initCommandOptions(CommandOptions& options)
         {OptionKind::WarningLevel,
          "-Wall,-Wextra,-Wpedantic",
          "-Wall | -Wextra | -Wpedantic",
-         "Enable the corresponding group of opt-in warnings (additive)."},
+         "Enable the corresponding group of opt-in warnings (additive). Staging: the pedantic "
+         "group is currently enabled by default, so -Wpedantic is a no-op today; a future release "
+         "will make it opt-in."},
         {OptionKind::EnableWarning, "-W...", "-W<id>", "Enable a warning with the specified id."},
         {OptionKind::DisableWarning, "-Wno-...", "-Wno-<id>", "Disable warning with <id>"},
         {OptionKind::DumpWarningDiagnostics,

tools/slang-unit-test/unit-test-diagnostic-warning-level.cpp

@@ -102,6 +102,24 @@ SLANG_UNIT_TEST(warningLevelWarningsAsErrorsInteraction)
     SLANG_CHECK(sink.getErrorCount() == 2);
 }
 
+// A child sink built from a parent inherits the parent's enabled warning groups. Sinks are
+// spun up per-translation-unit / per-module from a parent sink via the parent-copying ctor,
+// so an opt-in group enabled on the parent must carry over to nested/downstream compilations.
+SLANG_UNIT_TEST(warningLevelInheritedFromParentSink)
+{
+    DiagnosticSink parent;
+    parent.enableWarningLevel(WarningLevel::All);
+
+    // The parent-copying ctor forwards the enabled-group bitmask alongside flags/color/unicode.
+    DiagnosticSink child(nullptr, nullptr, &parent);
+
+    SLANG_CHECK(child.isWarningLevelEnabled(WarningLevel::All) == true);
+    SLANG_CHECK(emitted(child, makeWarning(3, WarningLevel::All)) == true);
+    // A group the parent did not enable is not inherited either.
+    SLANG_CHECK(child.isWarningLevelEnabled(WarningLevel::Extra) == false);
+    SLANG_CHECK(emitted(child, makeWarning(4, WarningLevel::Extra)) == false);
+}
+
 // Out-of-range group values (only reachable via a bogus int cast through the public
 // WarningLevel option) must not trigger an out-of-range shift / undefined behavior.
 SLANG_UNIT_TEST(warningLevelOutOfRangeIsSafe)