[C++11] Support for capturing of variable length arrays in lambda expression.

Differential Revision: http://reviews.llvm.org/D4368

llvm-svn: 216649

1 files changed, 30 insertions, 11 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 6a530c71ec2..d9278863534 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -11681,13 +11681,10 @@ static bool isVariableCapturable(CapturingScopeInfo *CSI, VarDecl *Var,
     return false;
   }
 
-  // Prohibit variably-modified types; they're difficult to deal with.
-  if (Var->getType()->isVariablyModifiedType() && (IsBlock || IsLambda)) {
+  // Prohibit variably-modified types in blocks; they're difficult to deal with.
+  if (Var->getType()->isVariablyModifiedType() && IsBlock) {
     if (Diagnose) {
-      if (IsBlock)
-        S.Diag(Loc, diag::err_ref_vm_type);
-      else
-        S.Diag(Loc, diag::err_lambda_capture_vm_type) << Var->getDeclName();
+      S.Diag(Loc, diag::err_ref_vm_type);
       S.Diag(Var->getLocation(), diag::note_previous_decl) 
         << Var->getDeclName();
     }
@@ -12091,7 +12088,6 @@ static bool captureInLambda(LambdaScopeInfo *LSI,
   return true;
 }
 
-
 bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc, 
                               TryCaptureKind Kind, SourceLocation EllipsisLoc,
                               bool BuildAndDiagnose, 
@@ -12228,14 +12224,37 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation ExprLoc,
           break;
         case Type::VariableArray: {
           // Losing element qualification here is fine.
-          const VariableArrayType *Vat = cast<VariableArrayType>(Ty);
+          const VariableArrayType *VAT = cast<VariableArrayType>(Ty);
 
           // Unknown size indication requires no size computation.
           // Otherwise, evaluate and record it.
-          if (Expr *Size = Vat->getSizeExpr()) {
-            MarkDeclarationsReferencedInExpr(Size);
+          if (auto Size = VAT->getSizeExpr()) {
+            if (auto LSI = dyn_cast<LambdaScopeInfo>(CSI)) {
+              if (!LSI->isVLATypeCaptured(VAT)) {
+                auto ExprLoc = Size->getExprLoc();
+                auto SizeType = Context.getSizeType();
+                auto Lambda = LSI->Lambda;
+
+                // Build the non-static data member.
+                auto Field = FieldDecl::Create(
+                    Context, Lambda, ExprLoc, ExprLoc,
+                    /*Id*/ nullptr, SizeType, /*TInfo*/ nullptr,
+                    /*BW*/ nullptr, /*Mutable*/ false,
+                    /*InitStyle*/ ICIS_NoInit);
+                Field->setImplicit(true);
+                Field->setAccess(AS_private);
+                Field->setCapturedVLAType(VAT);
+                Lambda->addDecl(Field);
+
+                LSI->addVLATypeCapture(ExprLoc, SizeType);
+              }
+            } else {
+              // Immediately mark all referenced vars for CapturedStatements,
+              // they all are captured by reference.
+              MarkDeclarationsReferencedInExpr(Size);
+            }
           }
-          QTy = Vat->getElementType();
+          QTy = VAT->getElementType();
           break;
         }
         case Type::FunctionProto: