Introduce basic ASTs for lambda expressions. This covers:

  - Capturing variables by-reference and by-copy within a lambda
  - The representation of lambda captures
  - The creation of the non-static data members in the lambda class
  that store the captured variables
  - The initialization of the non-static data members from the
  captured variables
  - Pretty-printing lambda expressions

There are a number of FIXMEs, both explicit and implied, including:
  - Creating a field for a capture of 'this'
  - Improved diagnostics for initialization failures when capturing
  variables by copy
  - Dealing with temporaries created during said initialization
  - Template instantiation
  - AST (de-)serialization
  - Binding and returning the lambda expression; turning it into a
  proper temporary
  - Lots and lots of semantic constraints
  - Parameter pack captures


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149977 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 92 insertions, 0 deletions

diff --git a/lib/AST/StmtPrinter.cpp b/lib/AST/StmtPrinter.cpp
index 7077be1d93..1e2a494daa 100644
--- a/lib/AST/StmtPrinter.cpp
+++ b/lib/AST/StmtPrinter.cpp
@@ -1263,6 +1263,98 @@ void StmtPrinter::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *Node) {
   OS << ")";
 }
 
+void StmtPrinter::VisitLambdaExpr(LambdaExpr *Node) {
+  OS << '[';
+  bool NeedComma = false;
+  switch (Node->getCaptureDefault()) {
+  case LCD_None:
+    break;
+
+  case LCD_ByCopy:
+    OS << '=';
+    NeedComma = true;
+    break;
+
+  case LCD_ByRef:
+    OS << '&';
+    NeedComma = true;
+    break;
+  }
+  for (LambdaExpr::capture_iterator C = Node->explicit_capture_begin(),
+                                 CEnd = Node->explicit_capture_end();
+       C != CEnd;
+       ++C) {
+    if (NeedComma)
+      OS << ", ";
+    NeedComma = true;
+
+    switch (C->getCaptureKind()) {
+    case LCK_This:
+      OS << "this";
+      break;
+
+    case LCK_ByRef:
+      if (Node->getCaptureDefault() != LCD_ByRef)
+        OS << '&';
+      OS << C->getCapturedVar()->getName();
+      break;
+
+    case LCK_ByCopy:
+      if (Node->getCaptureDefault() != LCD_ByCopy)
+        OS << '=';
+      OS << C->getCapturedVar()->getName();
+      break;
+    }
+  }
+  OS << ']';
+
+  if (Node->hasExplicitParameters()) {
+    OS << " (";
+    CXXMethodDecl *Method = Node->getCallOperator();
+    NeedComma = false;
+    for (CXXMethodDecl::param_iterator P = Method->param_begin(),
+                                    PEnd = Method->param_end();
+         P != PEnd; ++P) {
+      if (NeedComma) {
+        OS << ", ";
+      } else {
+        NeedComma = true;
+      }
+      std::string ParamStr = (*P)->getNameAsString();
+      (*P)->getOriginalType().getAsStringInternal(ParamStr, Policy);
+      OS << ParamStr;
+    }
+    if (Method->isVariadic()) {
+      if (NeedComma)
+        OS << ", ";
+      OS << "...";
+    }
+    OS << ')';
+
+    if (Node->isMutable())
+      OS << " mutable";
+
+    const FunctionProtoType *Proto
+      = Method->getType()->getAs<FunctionProtoType>();
+    {
+      std::string ExceptionSpec;
+      Proto->printExceptionSpecification(ExceptionSpec, Policy);
+      OS << ExceptionSpec;
+    }
+
+    // FIXME: Attributes
+
+    // FIXME: Suppress trailing return type if it wasn't specified in
+    // the source.
+    OS << " -> " << Proto->getResultType().getAsString(Policy);
+  }
+
+  // Print the body.
+  CompoundStmt *Body = Node->getBody();
+  OS << ' ';
+  PrintStmt(Body);
+}
+
 void StmtPrinter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *Node) {
   if (TypeSourceInfo *TSInfo = Node->getTypeSourceInfo())
     OS << TSInfo->getType().getAsString(Policy) << "()";