Revert "[clang][Sema] Add -Wswitch-default warning option (llvm#73077)"

This reverts commit 2cf433b.

Change-Id: I630da1ecf57cb003cc3062252b39e9e2b9ddf7d1

Author: bcahoon

clang/docs/ReleaseNotes.rst

@@ -470,8 +470,6 @@ Improvements to Clang's diagnostics
   of a base class is not called in the constructor of its derived class.
 - Clang no longer emits ``-Wmissing-variable-declarations`` for variables declared
   with the ``register`` storage class.
-- Clang's ``-Wswitch-default`` flag now diagnoses whenever a ``switch`` statement
-  does not have a ``default`` label.
 - Clang's ``-Wtautological-negation-compare`` flag now diagnoses logical
   tautologies like ``x && !x`` and ``!x || x`` in expressions. This also
   makes ``-Winfinite-recursion`` diagnose more cases.

clang/include/clang/Basic/DiagnosticGroups.td

@@ -634,7 +634,7 @@ def ShadowAll : DiagGroup<"shadow-all", [Shadow, ShadowFieldInConstructor,
 def Shorten64To32 : DiagGroup<"shorten-64-to-32">;
 def : DiagGroup<"sign-promo">;
 def SignCompare : DiagGroup<"sign-compare">;
-def SwitchDefault  : DiagGroup<"switch-default">;
+def : DiagGroup<"switch-default">;
 def : DiagGroup<"synth">;
 def SizeofArrayArgument : DiagGroup<"sizeof-array-argument">;
 def SizeofArrayDecay : DiagGroup<"sizeof-array-decay">;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -10098,8 +10098,6 @@ def warn_missing_case : Warning<"%plural{"
   "3:enumeration values %1, %2, and %3 not handled in switch|"
   ":%0 enumeration values not handled in switch: %1, %2, %3...}0">,
   InGroup<Switch>;
-def warn_switch_default : Warning<"'switch' missing 'default' label">,
-  InGroup<SwitchDefault>, DefaultIgnore;
 
 def warn_unannotated_fallthrough : Warning<
   "unannotated fall-through between switch labels">,

clang/lib/Sema/SemaStmt.cpp

@@ -1350,7 +1350,10 @@ Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
       assert(!HasConstantCond ||
              (ConstantCondValue.getBitWidth() == CondWidth &&
               ConstantCondValue.isSigned() == CondIsSigned));
+#if NEEDS_PATCH_FOR_SWITCH
+//[clang][Sema] Add -Wswitch-default warning option (#73077)
       Diag(SwitchLoc, diag::warn_switch_default);
+#endif
     }
     bool ShouldCheckConstantCond = HasConstantCond;
 

clang/test/Sema/switch-default.cpp

@@ -0,0 +1,55 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wswitch-default %s
+
+// XFAIL: *
+
+int f1(int a) {
+  switch (a) {                // expected-warning {{'switch' missing 'default' label}}
+    case 1: a++; break;
+    case 2: a += 2; break;
+  }
+  return a;
+}
+
+int f2(int a) {
+  switch (a) {                // no-warning
+    default:
+      ;
+  }
+  return a;
+}
+
+// Warn even completely covered Enum cases(GCC compatibility).
+enum E { A, B };
+enum E check_enum(enum E e) {
+  switch (e) {                // expected-warning {{'switch' missing 'default' label}}
+    case A: break;
+    case B: break;
+  }
+  return e;
+}
+
+template<typename Index>
+int t1(Index i)
+{
+  switch (i) {              // expected-warning {{'switch' missing 'default' label}}
+    case 0: return 0;
+    case 1: return 1;
+  }
+  return 0;
+}
+
+template<typename Index>
+int t2(Index i)
+{
+  switch (i) {            // no-warning
+    case 0: return 0;
+    case 1: return 1;
+    default: return 2;
+  }
+  return 0;
+}
+
+int main() {
+  return t1(1);       // expected-note {{in instantiation of function template specialization 't1<int>' requested here}}
+}
+

revert_patches.txt

@@ -1,2 +1,11 @@
+revert: breaks MIOpen composableKernel build 
+[clang][Sema] Add -Wswitch-default warning option (#73077)  
+   https://ontrack-internal.amd.com/browse/SWDEV-436625
+
+Reverts: breaks ompt tests
+[Libomptarget] Remove __tgt_image_info and use the ELF directly (#75720)
+
+64f0681e97c6 [Libomptarget] Rework image checking further (#76120) 
+
 Reverts: breaks HIP tests in wPSDB and nPSDB
 [AMDGPU] Add dynamic LDS size implicit kernel argument t