Split 'qualifier on reference type has no effect' out into a new flag

This introduces a new flag ignored-reference-qualifiers for the
existing "'A' qualifier on reference type B has no effect" diagnostic,
as a child of ignored-qualifiers.

Rationale:
This particular diagnostic is enabled by default, but other parts of
ignored-qualifiers are not. Anecdotally, a user may encounter this
diagnostic in the wild, and, seeing it to be valuable, might try to
raise it to error with -Werror=ignored-qualifiers, whereupon the other
diagnostics the flag covers will also be raised, to the user's surprise
and confusion. By splitting this diagnostic out into a separate flag,
and marking it as a child of ignored-qualifiers, we allow the user more
granular control of the diagnostics they care about, while maintaining
backwards compatibility with existing build scripts.

diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 6857c88..1555a9e 100644 (file)
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -402,7 +402,8 @@ def IncrementBool : DiagGroup<"increment-bool", [DeprecatedIncrementBool]>;
 def InfiniteRecursion : DiagGroup<"infinite-recursion">;
 def PureVirtualCallFromCtorDtor: DiagGroup<"call-to-pure-virtual-from-ctor-dtor">;
 def GNUImaginaryConstant : DiagGroup<"gnu-imaginary-constant">;
-def IgnoredQualifiers : DiagGroup<"ignored-qualifiers">;
+def IgnoredReferenceQualifiers : DiagGroup<"ignored-reference-qualifiers">;
+def IgnoredQualifiers : DiagGroup<"ignored-qualifiers", [IgnoredReferenceQualifiers]>;
 def : DiagGroup<"import">;
 def GNUIncludeNext : DiagGroup<"gnu-include-next">;
 def IncompatibleMSStruct : DiagGroup<"incompatible-ms-struct">;

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 247f9d7..4ed561f 100644 (file)
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -5735,7 +5735,7 @@ def warn_typecheck_function_qualifiers_unspecified : Warning<
   "'%0' qualifier on function type %1 has unspecified behavior">;
 def warn_typecheck_reference_qualifiers : Warning<
   "'%0' qualifier on reference type %1 has no effect">,
-  InGroup<IgnoredQualifiers>;
+  InGroup<IgnoredReferenceQualifiers>;
 def err_typecheck_invalid_restrict_not_pointer : Error<
   "restrict requires a pointer or reference (%0 is invalid)">;
 def err_typecheck_invalid_restrict_not_pointer_noarg : Error<