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

[Richard Smith]

================
Comment at: include/clang/AST/LambdaCapture.h:67
@@ -66,3 +66,3 @@
   /// \brief Determine the kind of capture.
   LambdaCaptureKind getCaptureKind() const;
 
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Have you considered adding an LCK_ value for VLA capture? Calling it `LCK_ByCopy` doesn't seem quite right.

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Comment at: lib/AST/Decl.cpp:3303-3305
@@ -3292,4 +3302,5 @@
 void FieldDecl::setBitWidth(Expr *Width) {
+  assert(isBitField() && "not a bitfield");
   assert(!InitializerOrBitWidth.getPointer() && !hasInClassInitializer() &&
-         "bit width or initializer already set");
+         "bit width, initializer or captured type already set");
   InitializerOrBitWidth.setPointer(Width);
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This pair of asserts doesn't make sense. A field can only be a bit-field if it has a bit-width, but you're asserting that it's a bit-field *and* has no bit-width.

This is only passing the tests because `setBitWidth` is never called. Please remove the assert you added here. (I suspect this function is called by lldb or similar, otherwise I'd just suggest removing it entirely.)

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Comment at: lib/AST/Decl.cpp:3317
@@ +3316,3 @@
+  return getDeclContext()->isRecord() && getParent()->isLambda() &&
+         getInClassInitStyle() == ICIS_NoInit &&
+         InitializerOrBitWidth.getPointer();
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Is this check necessary? You can't have an in-class initializer in a lambda.

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Comment at: lib/AST/Decl.cpp:3549-3551
@@ +3548,5 @@
+bool RecordDecl::isLambda() const {
+  if (auto RD = dyn_cast<CXXRecordDecl>(this)) {
+    return RD->isLambda();
+  }
+  return false;
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No braces here, please.

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Comment at: lib/AST/StmtPrinter.cpp:1711-1712
@@ -1710,2 +1710,4 @@
        ++C) {
+    if (C->capturesVLAType())
+      continue;
     if (NeedComma)
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Is this possible? I would have expected VLA captures to always be implicit.

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Comment at: lib/AST/StmtProfile.cpp:1020-1021
@@ -1019,2 +1019,4 @@
        C != CEnd; ++C) {
+    if (C->capturesVLAType())
+      continue;
     ID.AddInteger(C->getCaptureKind());
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Likewise.

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Comment at: lib/Sema/SemaExpr.cpp:11668
@@ -11667,2 +11667,3 @@
 
   // Prohibit variably-modified types; they're difficult to deal with.
+  if (Var->getType()->isVariablyModifiedType() && IsBlock) {
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Update this comment: "Prohibit variably-modified types in blocks; ..." maybe?

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Comment at: lib/Sema/SemaExpr.cpp:12075-12082
@@ -12077,2 +12074,10 @@
 
+static bool isVLATypeIsCaptured(LambdaScopeInfo *LSI,
+                                const VariableArrayType *VAT) {
+  for (auto *FD : LSI->Lambda->fields()) {
+    if (FD->hasCapturedVLAType() && FD->getCapturedVLAType() == VAT)
+      return true;
+  }
+  return false;
+}
 
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Please make this a member of `CapturingScopeInfo`. Also, drop one of the `Is`s from its name.

http://reviews.llvm.org/D4368