Separate out the initialization kind for a statement expression result

from that for a return value.

No functionality change intended: I don't believe any of the diagnostics
affected by this patch are reachable when initializing the result of
statement expression.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@337728 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index e45f5f3376accec6e308d804d231dab49cf072fa..c6f263dc8ce6e25da6161c5ff3c417d43d38e1c2 100644 (file)
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1804,7 +1804,8 @@ def err_destructor_template : Error<
 
 // C++ initialization
 def err_init_conversion_failed : Error<
-  "cannot initialize %select{a variable|a parameter|return object|an "
+  "cannot initialize %select{a variable|a parameter|return object|"
+  "statement expression result|an "
   "exception object|a member subobject|an array element|a new value|a value|a "
   "base class|a constructor delegation|a vector element|a block element|a "
   "block element|a complex element|a lambda capture|a compound literal "
@@ -1939,34 +1940,29 @@ def warn_unsequenced_mod_mod : Warning<
 def warn_unsequenced_mod_use : Warning<
   "unsequenced modification and access to %0">, InGroup<Unsequenced>;
 
+def select_initialized_entity_kind : TextSubstitution<
+  "%select{copying variable|copying parameter|"
+  "returning object|initializing statement expression result|"
+  "throwing object|copying member subobject|copying array element|"
+  "allocating object|copying temporary|initializing base subobject|"
+  "initializing vector element|capturing value}0">;
+
 def err_temp_copy_no_viable : Error<
-  "no viable constructor %select{copying variable|copying parameter|"
-  "returning object|throwing object|copying member subobject|copying array "
-  "element|allocating object|copying temporary|initializing base subobject|"
-  "initializing vector element|capturing value}0 of type %1">;
+  "no viable constructor %sub{select_initialized_entity_kind}0 of type %1">;
 def ext_rvalue_to_reference_temp_copy_no_viable : Extension<
-  "no viable constructor %select{copying variable|copying parameter|"
-  "returning object|throwing object|copying member subobject|copying array "
-  "element|allocating object|copying temporary|initializing base subobject|"
-  "initializing vector element|capturing value}0 of type %1; C++98 requires a copy "
-  "constructor when binding a reference to a temporary">,
+  "no viable constructor %sub{select_initialized_entity_kind}0 of type %1; "
+  "C++98 requires a copy constructor when binding a reference to a temporary">,
   InGroup<BindToTemporaryCopy>;
 def err_temp_copy_ambiguous : Error<
-  "ambiguous constructor call when %select{copying variable|copying "
-  "parameter|returning object|throwing object|copying member subobject|copying "
-  "array element|allocating object|copying temporary|initializing base subobject|"
-  "initializing vector element|capturing value}0 of type %1">;
+  "ambiguous constructor call when %sub{select_initialized_entity_kind}0 "
+  "of type %1">;
 def err_temp_copy_deleted : Error<
-  "%select{copying variable|copying parameter|returning object|throwing "
-  "object|copying member subobject|copying array element|allocating object|"
-  "copying temporary|initializing base subobject|initializing vector element|"
-  "capturing value}0 of type %1 invokes deleted constructor">;
+  "%sub{select_initialized_entity_kind}0 of type %1 "
+  "invokes deleted constructor">;
 def err_temp_copy_incomplete : Error<
   "copying a temporary object of incomplete type %0">;
 def warn_cxx98_compat_temp_copy : Warning<
-  "%select{copying variable|copying parameter|returning object|throwing "
-  "object|copying member subobject|copying array element|allocating object|"
-  "copying temporary|initializing base subobject|initializing vector element}1 "
+  "%sub{select_initialized_entity_kind}1 "
   "of type %2 when binding a reference to a temporary would %select{invoke "
   "an inaccessible constructor|find no viable constructor|find ambiguous "
   "constructors|invoke a deleted constructor}0 in C++98">,

diff --git a/include/clang/Sema/Initialization.h b/include/clang/Sema/Initialization.h
index b7ef8d0f47bcb69afa277bf85113b722c4fe9357..7a510f391bda4102c3eba98f73803215bcafc5cd 100644 (file)
--- a/include/clang/Sema/Initialization.h
+++ b/include/clang/Sema/Initialization.h
@@ -59,6 +59,9 @@ public:
     /// The entity being initialized is the result of a function call.
     EK_Result,
 
+    /// The entity being initialized is the result of a statement expression.
+    EK_StmtExprResult,
+
     /// The entity being initialized is an exception object that
     /// is being thrown.
     EK_Exception,
@@ -285,6 +288,11 @@ public:
     return InitializedEntity(EK_Result, ReturnLoc, Type, NRVO);
   }
 
+  static InitializedEntity InitializeStmtExprResult(SourceLocation ReturnLoc,
+                                            QualType Type) {
+    return InitializedEntity(EK_StmtExprResult, ReturnLoc, Type);
+  }
+
   static InitializedEntity InitializeBlock(SourceLocation BlockVarLoc,
                                            QualType Type, bool NRVO) {
     return InitializedEntity(EK_BlockElement, BlockVarLoc, Type, NRVO);

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index fc70c882c227d1148f3f402e8422bbd02b7025a5..a72f6c3796d64fc9b8389e66c8fc13bd096e0c2e 100644 (file)
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -12992,11 +12992,8 @@ Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt,
           LastExpr = rebuiltLastStmt;
         } else {
           LastExpr = PerformCopyInitialization(
-                            InitializedEntity::InitializeResult(LPLoc, 
-                                                                Ty,
-                                                                false),
-                                                   SourceLocation(),
-                                               LastExpr);
+              InitializedEntity::InitializeStmtExprResult(LPLoc, Ty),
+              SourceLocation(), LastExpr);
         }
 
         if (LastExpr.isInvalid())

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 6c2c6d143da0af150a1380a1e666267b200e6c42..e457de4dcc74bbffcad128f8c80390023583ccc6 100644 (file)
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -1020,6 +1020,7 @@ static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity,
   case InitializedEntity::EK_BlockElement:
   case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
   case InitializedEntity::EK_Binding:
+  case InitializedEntity::EK_StmtExprResult:
     llvm_unreachable("unexpected braced scalar init");
   }
 
@@ -3000,6 +3001,7 @@ DeclarationName InitializedEntity::getName() const {
     return DeclarationName(Capture.VarID);
       
   case EK_Result:
+  case EK_StmtExprResult:
   case EK_Exception:
   case EK_New:
   case EK_Temporary:
@@ -3030,6 +3032,7 @@ ValueDecl *InitializedEntity::getDecl() const {
     return reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1);
 
   case EK_Result:
+  case EK_StmtExprResult:
   case EK_Exception:
   case EK_New:
   case EK_Temporary:
@@ -3055,6 +3058,7 @@ bool InitializedEntity::allowsNRVO() const {
   case EK_Exception:
     return LocAndNRVO.NRVO;
 
+  case EK_StmtExprResult:
   case EK_Variable:
   case EK_Parameter:
   case EK_Parameter_CF_Audited:
@@ -3090,6 +3094,7 @@ unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const {
   case EK_Parameter_CF_Audited: OS << "CF audited function Parameter";
     break;
   case EK_Result: OS << "Result"; break;
+  case EK_StmtExprResult: OS << "StmtExprResult"; break;
   case EK_Exception: OS << "Exception"; break;
   case EK_Member: OS << "Member"; break;
   case EK_Binding: OS << "Binding"; break;
@@ -3534,7 +3539,8 @@ static void MaybeProduceObjCObject(Sema &S,
   /// retainable type, then returns need to immediately retain the
   /// object.  If an autorelease is required, it will be done at the
   /// last instant.
-  } else if (Entity.getKind() == InitializedEntity::EK_Result) {
+  } else if (Entity.getKind() == InitializedEntity::EK_Result ||
+             Entity.getKind() == InitializedEntity::EK_StmtExprResult) {
     if (!Entity.getType()->isObjCRetainableType())
       return;
 
@@ -5632,6 +5638,7 @@ getAssignmentAction(const InitializedEntity &Entity, bool Diagnose = false) {
     return !Diagnose ? Sema::AA_Passing : Sema::AA_Passing_CFAudited;
       
   case InitializedEntity::EK_Result:
+  case InitializedEntity::EK_StmtExprResult: // FIXME: Not quite right.
     return Sema::AA_Returning;
 
   case InitializedEntity::EK_Temporary:
@@ -5661,6 +5668,7 @@ static bool shouldBindAsTemporary(const InitializedEntity &Entity) {
   case InitializedEntity::EK_ArrayElement:
   case InitializedEntity::EK_Member:
   case InitializedEntity::EK_Result:
+  case InitializedEntity::EK_StmtExprResult:
   case InitializedEntity::EK_New:
   case InitializedEntity::EK_Variable:
   case InitializedEntity::EK_Base:
@@ -5690,6 +5698,7 @@ static bool shouldBindAsTemporary(const InitializedEntity &Entity) {
 static bool shouldDestroyEntity(const InitializedEntity &Entity) {
   switch (Entity.getKind()) {
     case InitializedEntity::EK_Result:
+    case InitializedEntity::EK_StmtExprResult:
     case InitializedEntity::EK_New:
     case InitializedEntity::EK_Base:
     case InitializedEntity::EK_Delegating:
@@ -5721,6 +5730,7 @@ static SourceLocation getInitializationLoc(const InitializedEntity &Entity,
                                            Expr *Initializer) {
   switch (Entity.getKind()) {
   case InitializedEntity::EK_Result:
+  case InitializedEntity::EK_StmtExprResult:
     return Entity.getReturnLoc();
 
   case InitializedEntity::EK_Exception:
@@ -6168,6 +6178,7 @@ InitializedEntityOutlivesFullExpression(const InitializedEntity &Entity) {
   switch (Top->getKind()) {
   case InitializedEntity::EK_Variable:
   case InitializedEntity::EK_Result:
+  case InitializedEntity::EK_StmtExprResult:
   case InitializedEntity::EK_Exception:
   case InitializedEntity::EK_Member:
   case InitializedEntity::EK_Binding:
@@ -6216,6 +6227,10 @@ enum LifetimeKind {
   /// the entity is a return object.
   LK_Return,
 
+  /// The lifetime of a temporary bound to this entity ends too soon, because
+  /// the entity is the result of a statement expression.
+  LK_StmtExprResult,
+
   /// This is a mem-initializer: if it would extend a temporary (other than via
   /// a default member initializer), the program is ill-formed.
   LK_MemInitializer,
@@ -6274,6 +6289,11 @@ static LifetimeResult getEntityLifetime(
     //      destroyed at the end of the full-expression in the return statement.
     return {nullptr, LK_Return};
 
+  case InitializedEntity::EK_StmtExprResult:
+    // FIXME: Should we lifetime-extend through the result of a statement
+    // expression?
+    return {nullptr, LK_StmtExprResult};
+
   case InitializedEntity::EK_New:
     //   -- A temporary bound to a reference in a new-initializer persists
     //      until the completion of the full-expression containing the
@@ -6582,6 +6602,7 @@ void Sema::checkInitializerLifetime(const InitializedEntity &Entity,
         break;
 
       case LK_Return:
+      case LK_StmtExprResult:
         // FIXME: Move -Wreturn-stack-address checks here.
         return false;
       }
@@ -6660,6 +6681,7 @@ void Sema::checkInitializerLifetime(const InitializedEntity &Entity,
       break;
 
     case LK_Return:
+    case LK_StmtExprResult:
       // FIXME: Move -Wreturn-stack-address checks here.
       return false;
     }