commit ab8b2e08c3b8e1753a22c6ca2c966add96087689
author Mike Stump <mrs@apple.com> Tue Oct 27 01:59:05 2009 +0000
committer Mike Stump <mrs@apple.com> Tue Oct 27 01:59:05 2009 +0000
tree 2e6f2ecba8a125a2ffa73a801005a229826334ad
parent 60c143eff0abac28b72c79ed31963fe6fbfffd2a

Refine noreturn handling.  Fixes -Wmissing-noreturn so that it doesn't
complain that functions that have a return statement should be
declared noreturn.  Fixed PR5286.

llvm-svn: 85195

clang/lib/Sema/Sema.h

diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index fa10dea..f108878 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -988,7 +988,7 @@
   void CheckCXXDefaultArguments(FunctionDecl *FD);
   void CheckExtraCXXDefaultArguments(Declarator &D);
   enum ControlFlowKind { NeverFallThrough = 0, MaybeFallThrough = 1,
-                         AlwaysFallThrough = 2 };
+                         AlwaysFallThrough = 2, NeverFallThroughOrReturn = 3 };
   ControlFlowKind CheckFallThrough(Stmt *);
 
   Scope *getNonFieldDeclScope(Scope *S);

clang/lib/Sema/SemaDecl.cpp

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 8277a6a..886b886 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -1044,6 +1044,7 @@
 /// Statement that should return a value.
 ///
 /// \returns AlwaysFallThrough iff we always fall off the end of the statement,
+/// MaybeFallThroughOrReturn iff we might or might not fall off the end and
 /// MaybeFallThrough iff we might or might not fall off the end and
 /// NeverFallThrough iff we never fall off the end of the statement.  We assume
 /// that functions not marked noreturn will return.
@@ -1054,7 +1055,8 @@
 
   // FIXME: They should never return 0, fix that, delete this code.
   if (cfg == 0)
-    return NeverFallThrough;
+    // FIXME: This should be NeverFallThrough
+    return NeverFallThroughOrReturn;
   // The CFG leaves in dead things, and we don't want to dead code paths to
   // confuse us, so we mark all live things first.
   std::queue<CFGBlock*> workq;
@@ -1127,8 +1129,11 @@
     if (NoReturnEdge == false)
       HasPlainEdge = true;
   }
-  if (!HasPlainEdge)
-    return NeverFallThrough;
+  if (!HasPlainEdge) {
+    if (HasLiveReturn)
+      return NeverFallThrough;
+    return NeverFallThroughOrReturn;
+  }
   if (HasFakeEdge || HasLiveReturn)
     return MaybeFallThrough;
   // This says AlwaysFallThrough for calls to functions that are not marked
@@ -1192,10 +1197,12 @@
       else if (!ReturnsVoid)
         Diag(Compound->getRBracLoc(), diag::warn_falloff_nonvoid_function);
       break;
-    case NeverFallThrough:
+    case NeverFallThroughOrReturn:
       if (ReturnsVoid && !HasNoReturn)
         Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_function);
       break;
+    case NeverFallThrough:
+      break;
     }
   }
 }
@@ -1243,10 +1250,12 @@
       else if (!ReturnsVoid)
         Diag(Compound->getRBracLoc(), diag::err_falloff_nonvoid_block);
       break;
-    case NeverFallThrough:
+    case NeverFallThroughOrReturn:
       if (ReturnsVoid)
         Diag(Compound->getLBracLoc(), diag::warn_suggest_noreturn_block);
       break;
+    case NeverFallThrough:
+      break;
     }
   }
 }