Merge {Maybe,Always}FallThrough_ReturnsNonVoid into FallThrough_ReturnsNonVoid

Author: Igor S. Gerasimov

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -713,12 +713,8 @@ def err_thread_non_global : Error<
 def err_thread_unsupported : Error<
   "thread-local storage is not supported for the current target">;
 
-// FIXME: Combine fallout warnings to just one warning.
-def warn_maybe_falloff_nonvoid_function : Warning<
-  "non-void function does not return a value in all control paths">,
-  InGroup<ReturnType>;
 def warn_falloff_nonvoid_function : Warning<
-  "non-void function does not return a value">,
+  "non-void function does not return a value%select{| in all control paths}0">,
   InGroup<ReturnType>;
 def warn_const_attr_with_pure_attr : Warning<
   "'const' attribute imposes more restrictions; 'pure' attribute ignored">,
@@ -727,15 +723,10 @@ def warn_pure_function_returns_void : Warning<
   "'%select{pure|const}0' attribute on function returning 'void'; attribute ignored">,
   InGroup<IgnoredAttributes>;
 
-def err_maybe_falloff_nonvoid_block : Error<
-  "non-void block does not return a value in all control paths">;
 def err_falloff_nonvoid_block : Error<
-  "non-void block does not return a value">;
-def warn_maybe_falloff_nonvoid_coroutine : Warning<
-  "non-void coroutine does not return a value in all control paths">,
-  InGroup<ReturnType>;
+  "non-void block does not return a value%select{| in all control paths}0">;
 def warn_falloff_nonvoid_coroutine : Warning<
-  "non-void coroutine does not return a value">,
+  "non-void coroutine does not return a value%select{| in all control paths}0">,
   InGroup<ReturnType>;
 def warn_suggest_noreturn_function : Warning<
   "%select{function|method}0 %1 could be declared with attribute 'noreturn'">,
@@ -8408,11 +8399,8 @@ let CategoryName = "Lambda Issue" in {
     "incomplete result type %0 in lambda expression">;
   def err_noreturn_lambda_has_return_expr : Error<
     "lambda declared 'noreturn' should not return">;
-  def warn_maybe_falloff_nonvoid_lambda : Warning<
-    "non-void lambda does not return a value in all control paths">,
-    InGroup<ReturnType>;
   def warn_falloff_nonvoid_lambda : Warning<
-    "non-void lambda does not return a value">,
+    "non-void lambda does not return a value%select{| in all control paths}0">,
     InGroup<ReturnType>;
   def err_access_lambda_capture : Error<
     // The ERRORs represent other special members that aren't constructors, in

clang/lib/Sema/AnalysisBasedWarnings.cpp

@@ -544,24 +544,18 @@ static ControlFlowKind CheckFallThrough(AnalysisDeclContext &AC) {
 namespace {
 
 struct CheckFallThroughDiagnostics {
-  unsigned diag_MaybeFallThrough_HasNoReturn;
-  unsigned diag_MaybeFallThrough_ReturnsNonVoid;
-  unsigned diag_AlwaysFallThrough_HasNoReturn;
-  unsigned diag_AlwaysFallThrough_ReturnsNonVoid;
+  unsigned diag_FallThrough_HasNoReturn;
+  unsigned diag_FallThrough_ReturnsNonVoid;
   unsigned diag_NeverFallThroughOrReturn;
   enum { Function, Block, Lambda, Coroutine } funMode;
   SourceLocation FuncLoc;
 
   static CheckFallThroughDiagnostics MakeForFunction(const Decl *Func) {
     CheckFallThroughDiagnostics D;
     D.FuncLoc = Func->getLocation();
-    D.diag_MaybeFallThrough_HasNoReturn =
+    D.diag_FallThrough_HasNoReturn =
       diag::warn_falloff_noreturn_function;
-    D.diag_MaybeFallThrough_ReturnsNonVoid =
-      diag::warn_maybe_falloff_nonvoid_function;
-    D.diag_AlwaysFallThrough_HasNoReturn =
-      diag::warn_falloff_noreturn_function;
-    D.diag_AlwaysFallThrough_ReturnsNonVoid =
+    D.diag_FallThrough_ReturnsNonVoid =
       diag::warn_falloff_nonvoid_function;
 
     // Don't suggest that virtual functions be marked "noreturn", since they
@@ -588,11 +582,8 @@ struct CheckFallThroughDiagnostics {
   static CheckFallThroughDiagnostics MakeForCoroutine(const Decl *Func) {
     CheckFallThroughDiagnostics D;
     D.FuncLoc = Func->getLocation();
-    D.diag_MaybeFallThrough_HasNoReturn = 0;
-    D.diag_MaybeFallThrough_ReturnsNonVoid =
-        diag::warn_maybe_falloff_nonvoid_coroutine;
-    D.diag_AlwaysFallThrough_HasNoReturn = 0;
-    D.diag_AlwaysFallThrough_ReturnsNonVoid =
+    D.diag_FallThrough_HasNoReturn = 0;
+    D.diag_FallThrough_ReturnsNonVoid =
         diag::warn_falloff_nonvoid_coroutine;
     D.diag_NeverFallThroughOrReturn = 0;
     D.funMode = Coroutine;
@@ -601,13 +592,9 @@ struct CheckFallThroughDiagnostics {
 
   static CheckFallThroughDiagnostics MakeForBlock() {
     CheckFallThroughDiagnostics D;
-    D.diag_MaybeFallThrough_HasNoReturn =
-      diag::err_noreturn_block_has_return_expr;
-    D.diag_MaybeFallThrough_ReturnsNonVoid =
-      diag::err_maybe_falloff_nonvoid_block;
-    D.diag_AlwaysFallThrough_HasNoReturn =
+    D.diag_FallThrough_HasNoReturn =
       diag::err_noreturn_block_has_return_expr;
-    D.diag_AlwaysFallThrough_ReturnsNonVoid =
+    D.diag_FallThrough_ReturnsNonVoid =
       diag::err_falloff_nonvoid_block;
     D.diag_NeverFallThroughOrReturn = 0;
     D.funMode = Block;
@@ -616,13 +603,9 @@ struct CheckFallThroughDiagnostics {
 
   static CheckFallThroughDiagnostics MakeForLambda() {
     CheckFallThroughDiagnostics D;
-    D.diag_MaybeFallThrough_HasNoReturn =
-      diag::err_noreturn_lambda_has_return_expr;
-    D.diag_MaybeFallThrough_ReturnsNonVoid =
-      diag::warn_maybe_falloff_nonvoid_lambda;
-    D.diag_AlwaysFallThrough_HasNoReturn =
+    D.diag_FallThrough_HasNoReturn =
       diag::err_noreturn_lambda_has_return_expr;
-    D.diag_AlwaysFallThrough_ReturnsNonVoid =
+    D.diag_FallThrough_ReturnsNonVoid =
       diag::warn_falloff_nonvoid_lambda;
     D.diag_NeverFallThroughOrReturn = 0;
     D.funMode = Lambda;
@@ -633,7 +616,7 @@ struct CheckFallThroughDiagnostics {
                         bool HasNoReturn) const {
     if (funMode == Function) {
       return (ReturnsVoid ||
-              D.isIgnored(diag::warn_maybe_falloff_nonvoid_function,
+              D.isIgnored(diag::warn_falloff_nonvoid_function,
                           FuncLoc)) &&
              (!HasNoReturn ||
               D.isIgnored(diag::warn_noreturn_function_has_return_expr,
@@ -643,8 +626,8 @@ struct CheckFallThroughDiagnostics {
     }
     if (funMode == Coroutine) {
       return (ReturnsVoid ||
-              D.isIgnored(diag::warn_maybe_falloff_nonvoid_function, FuncLoc) ||
-              D.isIgnored(diag::warn_maybe_falloff_nonvoid_coroutine,
+              D.isIgnored(diag::warn_falloff_nonvoid_function, FuncLoc) ||
+              D.isIgnored(diag::warn_falloff_nonvoid_coroutine,
                           FuncLoc)) &&
              (!HasNoReturn);
     }
@@ -714,15 +697,15 @@ static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body,
 
     case MaybeFallThrough:
       if (HasNoReturn)
-        EmitDiag(RBrace, CD.diag_MaybeFallThrough_HasNoReturn);
+        EmitDiag(RBrace, CD.diag_FallThrough_HasNoReturn);
       else if (!ReturnsVoid)
-        EmitDiag(RBrace, CD.diag_MaybeFallThrough_ReturnsNonVoid);
+        S.Diag(RBrace, CD.diag_FallThrough_ReturnsNonVoid) << 1;
       break;
     case AlwaysFallThrough:
       if (HasNoReturn)
-        EmitDiag(RBrace, CD.diag_AlwaysFallThrough_HasNoReturn);
+        EmitDiag(RBrace, CD.diag_FallThrough_HasNoReturn);
       else if (!ReturnsVoid)
-        EmitDiag(RBrace, CD.diag_AlwaysFallThrough_ReturnsNonVoid);
+        S.Diag(RBrace, CD.diag_FallThrough_ReturnsNonVoid) << 0;
       break;
     case NeverFallThroughOrReturn:
       if (ReturnsVoid && !HasNoReturn && CD.diag_NeverFallThroughOrReturn) {