add a -Wdeprecated-switch-case flag

Author: zmodem

clang/include/clang/Basic/DiagnosticGroups.td

@@ -233,7 +233,8 @@ def DeprecatedCopyWithDtor : DiagGroup<"deprecated-copy-with-dtor", [DeprecatedC
 def DeprecatedLiteralOperator : DiagGroup<"deprecated-literal-operator">;
 // For compatibility with GCC.
 def : DiagGroup<"deprecated-copy-dtor", [DeprecatedCopyWithDtor]>;
-def DeprecatedDeclarations : DiagGroup<"deprecated-declarations">;
+def DeprecatedSwitchCase : DiagGroup<"deprecated-switch-case">;
+def DeprecatedDeclarations : DiagGroup<"deprecated-declarations", [DeprecatedSwitchCase]>;
 def DeprecatedRedundantConstexprStaticDef : DiagGroup<"deprecated-redundant-constexpr-static-def">;
 def UnavailableDeclarations : DiagGroup<"unavailable-declarations">;
 def UnguardedAvailabilityNew : DiagGroup<"unguarded-availability-new">;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -6009,6 +6009,8 @@ def note_not_found_by_two_phase_lookup : Note<"%0 should be declared prior to th
 def err_undeclared_use : Error<"use of undeclared %0">;
 def warn_deprecated : Warning<"%0 is deprecated">,
     InGroup<DeprecatedDeclarations>;
+def warn_deprecated_switch_case : Warning<"%0 is deprecated">,
+    InGroup<DeprecatedSwitchCase>;
 def note_from_diagnose_if : Note<"from 'diagnose_if' attribute on %0:">;
 def warn_property_method_deprecated :
     Warning<"property access is using %0 method which is deprecated">,

clang/lib/Sema/SemaAvailability.cpp

@@ -549,13 +549,13 @@ static void DoEmitAvailabilityWarning(Sema &S, AvailabilityResult K,
     return;
   }
   case AR_Deprecated:
-    // Don't diagnose deprecated values in case expressions: they still need to
-    // be handled for the switch to be considered covered.
-    if (S.currentEvaluationContext().IsCaseExpr)
-      return;
+    if (ObjCPropertyAccess)
+      diag = diag::warn_property_method_deprecated;
+    else if (S.currentEvaluationContext().IsCaseExpr)
+      diag = diag::warn_deprecated_switch_case;
+    else
+      diag = diag::warn_deprecated;
 
-    diag = !ObjCPropertyAccess ? diag::warn_deprecated
-                               : diag::warn_property_method_deprecated;
     diag_message = diag::warn_deprecated_message;
     diag_fwdclass_message = diag::warn_deprecated_fwdclass_message;
     property_note_select = /* deprecated */ 0;

clang/test/Sema/switch-availability.c

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -verify -Wswitch -Wreturn-type -triple x86_64-apple-macosx10.12 %s
+// RUN: %clang_cc1 -verify -Wswitch -Wreturn-type -Wno-deprecated-switch-case -DNO_DEPRECATED_CASE -triple x86_64-apple-macosx10.12 %s
 
 enum SwitchOne {
   Unavail __attribute__((availability(macos, unavailable))),
@@ -29,6 +30,9 @@ void testSwitchThree(enum SwitchThree st) {
 enum SwitchFour {
   Red,
   Green,
+#ifndef NO_DEPRECATED_CASE
+// expected-note@+2{{'Blue' has been explicitly marked deprecated here}}
+#endif
   Blue [[deprecated]]
 };
 
@@ -43,6 +47,9 @@ int testSwitchFourCovered(enum SwitchFour e) {
   switch (e) {
   case Red:   return 1;
   case Green: return 2;
-  case Blue:  return 3; // no warning
-  }
+#ifndef NO_DEPRECATED_CASE
+// expected-warning@+2{{'Blue' is deprecated}}
+#endif
+  case Blue:  return 3;
+  } // no warning
 }

clang/test/SemaObjC/unguarded-availability.m

@@ -343,21 +343,21 @@ @interface BaseClass (CategoryWithNewProtocolRequirement) <NewProtocol>
 @end
 
 typedef enum {
-  AK_Dodo __attribute__((availability(macos, deprecated=10.3))), // expected-note 1 {{marked deprecated here}}
+  AK_Dodo __attribute__((availability(macos, deprecated=10.3))), // expected-note 3 {{marked deprecated here}}
   AK_Cat __attribute__((availability(macos, introduced=10.4))),
   AK_CyborgCat __attribute__((availability(macos, introduced=10.12))), // expected-note {{'AK_CyborgCat' has been marked as being introduced in macOS 10.12 here, but the deployment target is macOS 10.9}}
 } Animals;
 
 void switchAnimals(Animals a) {
   switch (a) {
-  case AK_Dodo: break; // no warn
+  case AK_Dodo: break; // expected-warning{{'AK_Dodo' is deprecated}}
   case AK_Cat: break;
   case AK_Cat|AK_CyborgCat: break; // expected-warning{{case value not in enum}}
   case AK_CyborgCat: break; // no warn
   }
 
   switch (a) {
-  case AK_Dodo...AK_CyborgCat: // no warn
+  case AK_Dodo...AK_CyborgCat: // expected-warning {{'AK_Dodo' is depr}}
     break;
   }