Basic support for name mangling of C++11 lambda expressions. Because

name mangling in the Itanium C++ ABI for lambda expressions is so
dependent on context, we encode the number used to encode each lambda
as part of the lambda closure type, and maintain this value within
Sema.

Note that there are a several pieces still missing:
  - We still get the linkage of lambda expressions wrong
  - We aren't properly numbering or mangling lambda expressions that
  occur in default function arguments or in data member initializers.
  - We aren't (de-)serializing the lambda numbering tables

llvm-svn: 150982

2 files changed, 14 insertions, 3 deletions

diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 1a362d48e28..d1f87a2c189 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -483,7 +483,9 @@ static void addBlockPointerConversion(Sema &S,
 }
 
 ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, 
-                                 Scope *CurScope, bool IsInstantiation) {
+                                 Scope *CurScope, 
+                                 llvm::Optional<unsigned> ManglingNumber,
+                                 bool IsInstantiation) {
   // Leave the expression-evaluation context.
   DiscardCleanupsInEvaluationContext();
   PopExpressionEvaluationContext();
@@ -633,11 +635,19 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
   if (LambdaExprNeedsCleanups)
     ExprNeedsCleanups = true;
 
+  // If we don't already have a mangling number for this lambda expression,
+  // allocate one now.
+  if (!ManglingNumber) {
+    // FIXME: Default arguments, data member initializers are special.
+    ManglingNumber = Context.getLambdaManglingNumber(CallOperator);
+  }
+  
   LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange, 
                                           CaptureDefault, Captures, 
                                           ExplicitParams, ExplicitResultType,
                                           CaptureInits, ArrayIndexVars, 
-                                          ArrayIndexStarts, Body->getLocEnd());
+                                          ArrayIndexStarts, Body->getLocEnd(),
+                                          *ManglingNumber);
 
   // C++11 [expr.prim.lambda]p2:
   //   A lambda-expression shall not appear in an unevaluated operand
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 8a47a37d1c6..7e095f7336b 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -7769,8 +7769,9 @@ TreeTransform<Derived>::TransformLambdaExpr(LambdaExpr *E) {
     return ExprError();    
   }
   
+  unsigned ManglingNumber = E->getLambdaClass()->getLambdaManglingNumber();
   return getSema().ActOnLambdaExpr(E->getLocStart(), Body.take(), 
-                                   /*CurScope=*/0, 
+                                   /*CurScope=*/0, ManglingNumber,
                                    /*IsInstantiation=*/true);
 }