First pass of semantic analysis for init-captures: check the initializer, build

a FieldDecl from it, and propagate both into the closure type and the
LambdaExpr.

You can't do much useful with them yet -- you can't use them within the body
of the lambda, because we don't have a representation for "the this of the
lambda, not the this of the enclosing context". We also don't have support or a
representation for a nested capture of an init-capture yet, which was intended
to work despite not being allowed by the current standard wording.

llvm-svn: 181985

1 files changed, 16 insertions, 4 deletions

diff --git a/clang/lib/AST/ExprCXX.cpp b/clang/lib/AST/ExprCXX.cpp
index 402d7b532b2..59e780ae0a1 100644
--- a/clang/lib/AST/ExprCXX.cpp
+++ b/clang/lib/AST/ExprCXX.cpp
@@ -811,7 +811,7 @@ CXXConstructExpr::CXXConstructExpr(ASTContext &C, StmtClass SC, QualType T,
 LambdaExpr::Capture::Capture(SourceLocation Loc, bool Implicit,
                              LambdaCaptureKind Kind, VarDecl *Var,
                              SourceLocation EllipsisLoc)
-  : VarAndBits(Var, 0), Loc(Loc), EllipsisLoc(EllipsisLoc)
+  : DeclAndBits(Var, 0), Loc(Loc), EllipsisLoc(EllipsisLoc)
 {
   unsigned Bits = 0;
   if (Implicit)
@@ -828,15 +828,27 @@ LambdaExpr::Capture::Capture(SourceLocation Loc, bool Implicit,
   case LCK_ByRef:
     assert(Var && "capture must have a variable!");
     break;
+
+  case LCK_Init:
+    llvm_unreachable("don't use this constructor for an init-capture");
   }
-  VarAndBits.setInt(Bits);
+  DeclAndBits.setInt(Bits);
 }
 
+LambdaExpr::Capture::Capture(FieldDecl *Field)
+    : DeclAndBits(Field,
+                  Field->getType()->isReferenceType() ? 0 : Capture_ByCopy),
+      Loc(Field->getLocation()), EllipsisLoc() {}
+
 LambdaCaptureKind LambdaExpr::Capture::getCaptureKind() const {
-  if (capturesThis())
+  Decl *D = DeclAndBits.getPointer();
+  if (!D)
     return LCK_This;
 
-  return (VarAndBits.getInt() & Capture_ByCopy)? LCK_ByCopy : LCK_ByRef;
+  if (isa<FieldDecl>(D))
+    return LCK_Init;
+
+  return (DeclAndBits.getInt() & Capture_ByCopy) ? LCK_ByCopy : LCK_ByRef;
 }
 
 LambdaExpr::LambdaExpr(QualType T,