Defer creating fields for captures until we finish building the

capturing expression or statement.

No functionality change yet. The intent is that we will also delay
building the initialization expression until the enclosing context, so
that:
a) we build the initialization expression in the right context, and
b) we can elide captures that are not odr-used, as suggested by P0588R1.

This also consolidates some duplicated code building capture fields into
a single place.

llvm-svn: 361893

1 files changed, 5 insertions, 76 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 95be7af8b68..8eccb4b0c5d 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -4050,32 +4050,11 @@ static void captureVariablyModifiedType(ASTContext &Context, QualType T,
 
       // Unknown size indication requires no size computation.
       // Otherwise, evaluate and record it.
-      if (auto Size = VAT->getSizeExpr()) {
-        if (!CSI->isVLATypeCaptured(VAT)) {
-          RecordDecl *CapRecord = nullptr;
-          if (auto LSI = dyn_cast<LambdaScopeInfo>(CSI)) {
-            CapRecord = LSI->Lambda;
-          } else if (auto CRSI = dyn_cast<CapturedRegionScopeInfo>(CSI)) {
-            CapRecord = CRSI->TheRecordDecl;
-          }
-          if (CapRecord) {
-            auto ExprLoc = Size->getExprLoc();
-            auto SizeType = Context.getSizeType();
-            // Build the non-static data member.
-            auto Field =
-                FieldDecl::Create(Context, CapRecord, ExprLoc, ExprLoc,
-                                  /*Id*/ nullptr, SizeType, /*TInfo*/ nullptr,
-                                  /*BW*/ nullptr, /*Mutable*/ false,
-                                  /*InitStyle*/ ICIS_NoInit);
-            Field->setImplicit(true);
-            Field->setAccess(AS_private);
-            Field->setCapturedVLAType(VAT);
-            CapRecord->addDecl(Field);
-
-            CSI->addVLATypeCapture(ExprLoc, SizeType);
-          }
-        }
-      }
+      auto Size = VAT->getSizeExpr();
+      if (Size && !CSI->isVLATypeCaptured(VAT) &&
+          (isa<CapturedRegionScopeInfo>(CSI) || isa<LambdaScopeInfo>(CSI)))
+        CSI->addVLATypeCapture(Size->getExprLoc(), VAT, Context.getSizeType());
+
       T = VAT->getElementType();
       break;
     }
@@ -15367,18 +15346,6 @@ static bool captureInCapturedRegion(CapturedRegionScopeInfo *RSI,
     // The current implementation assumes that all variables are captured
     // by references. Since there is no capture by copy, no expression
     // evaluation will be needed.
-    RecordDecl *RD = RSI->TheRecordDecl;
-
-    FieldDecl *Field
-      = FieldDecl::Create(S.Context, RD, Loc, Loc, nullptr, CaptureType,
-                          S.Context.getTrivialTypeSourceInfo(CaptureType, Loc),
-                          nullptr, false, ICIS_NoInit);
-    Field->setImplicit(true);
-    Field->setAccess(AS_private);
-    RD->addDecl(Field);
-    if (S.getLangOpts().OpenMP && RSI->CapRegionKind == CR_OpenMP)
-      S.setOpenMPCaptureKind(Field, Var, RSI->OpenMPLevel);
-
     CopyExpr = new (S.Context) DeclRefExpr(
         S.Context, Var, RefersToCapturedVariable, DeclRefType, VK_LValue, Loc);
     Var->setReferenced(true);
@@ -15394,39 +15361,6 @@ static bool captureInCapturedRegion(CapturedRegionScopeInfo *RSI,
   return !Invalid;
 }
 
-/// Create a field within the lambda class for the variable
-/// being captured.
-static void addAsFieldToClosureType(Sema &S, LambdaScopeInfo *LSI,
-                                    QualType FieldType, QualType DeclRefType,
-                                    SourceLocation Loc,
-                                    bool RefersToCapturedVariable) {
-  CXXRecordDecl *Lambda = LSI->Lambda;
-
-  // Build the non-static data member.
-  FieldDecl *Field
-    = FieldDecl::Create(S.Context, Lambda, Loc, Loc, nullptr, FieldType,
-                        S.Context.getTrivialTypeSourceInfo(FieldType, Loc),
-                        nullptr, false, ICIS_NoInit);
-  // If the variable being captured has an invalid type, mark the lambda class
-  // as invalid as well.
-  if (!FieldType->isDependentType()) {
-    if (S.RequireCompleteType(Loc, FieldType, diag::err_field_incomplete)) {
-      Lambda->setInvalidDecl();
-      Field->setInvalidDecl();
-    } else {
-      NamedDecl *Def;
-      FieldType->isIncompleteType(&Def);
-      if (Def && Def->isInvalidDecl()) {
-        Lambda->setInvalidDecl();
-        Field->setInvalidDecl();
-      }
-    }
-  }
-  Field->setImplicit(true);
-  Field->setAccess(AS_private);
-  Lambda->addDecl(Field);
-}
-
 /// Capture the given variable in the lambda.
 static bool captureInLambda(LambdaScopeInfo *LSI,
                             VarDecl *Var,
@@ -15504,11 +15438,6 @@ static bool captureInLambda(LambdaScopeInfo *LSI,
     }
   }
 
-  // Capture this variable in the lambda.
-  if (BuildAndDiagnose && !Invalid)
-    addAsFieldToClosureType(S, LSI, CaptureType, DeclRefType, Loc,
-                            RefersToCapturedVariable);
-
   // Compute the type of a reference to this captured variable.
   if (ByRef)
     DeclRefType = CaptureType.getNonReferenceType();