Expose LambdaIntroducer::DefaultLoc in the AST's LambdaExpr.

Summary:
Source-centric tools need access to the location of a C++11
lambda expression's capture-default ('&' or '=') when it's present.
It's possible for them to find it by re-lexing and re-implementing
rules that Clang's parser has already applied, but the cost of storing
the SourceLocation and making it available to them is 32 bits per
LambdaExpr (a small delta, proportionally), and the simplification in
client code is significant.

Reviewers: rsmith

Reviewed By: rsmith

CC: cfe-commits, klimek, revane

Differential Revision: http://llvm-reviews.chandlerc.com/D1192

llvm-svn: 188121

5 files changed, 27 insertions, 11 deletions

diff --git a/clang/lib/AST/ExprCXX.cpp b/clang/lib/AST/ExprCXX.cpp
index 55bd1990f60..496697fc55b 100644
--- a/clang/lib/AST/ExprCXX.cpp
+++ b/clang/lib/AST/ExprCXX.cpp
@@ -854,10 +854,11 @@ LambdaCaptureKind LambdaExpr::Capture::getCaptureKind() const {
   return (DeclAndBits.getInt() & Capture_ByCopy) ? LCK_ByCopy : LCK_ByRef;
 }
 
-LambdaExpr::LambdaExpr(QualType T, 
+LambdaExpr::LambdaExpr(QualType T,
                        SourceRange IntroducerRange,
                        LambdaCaptureDefault CaptureDefault,
-                       ArrayRef<Capture> Captures, 
+                       SourceLocation CaptureDefaultLoc,
+                       ArrayRef<Capture> Captures,
                        bool ExplicitParams,
                        bool ExplicitResultType,
                        ArrayRef<Expr *> CaptureInits,
@@ -869,6 +870,7 @@ LambdaExpr::LambdaExpr(QualType T,
          T->isDependentType(), T->isDependentType(), T->isDependentType(),
          ContainsUnexpandedParameterPack),
     IntroducerRange(IntroducerRange),
+    CaptureDefaultLoc(CaptureDefaultLoc),
     NumCaptures(Captures.size()),
     CaptureDefault(CaptureDefault),
     ExplicitParams(ExplicitParams),
@@ -914,11 +916,12 @@ LambdaExpr::LambdaExpr(QualType T,
   }
 }
 
-LambdaExpr *LambdaExpr::Create(ASTContext &Context, 
+LambdaExpr *LambdaExpr::Create(ASTContext &Context,
                                CXXRecordDecl *Class,
                                SourceRange IntroducerRange,
                                LambdaCaptureDefault CaptureDefault,
-                               ArrayRef<Capture> Captures, 
+                               SourceLocation CaptureDefaultLoc,
+                               ArrayRef<Capture> Captures,
                                bool ExplicitParams,
                                bool ExplicitResultType,
                                ArrayRef<Expr *> CaptureInits,
@@ -938,8 +941,9 @@ LambdaExpr *LambdaExpr::Create(ASTContext &Context,
     Size += sizeof(VarDecl *) * ArrayIndexVars.size();
   }
   void *Mem = Context.Allocate(Size);
-  return new (Mem) LambdaExpr(T, IntroducerRange, CaptureDefault, 
-                              Captures, ExplicitParams, ExplicitResultType,
+  return new (Mem) LambdaExpr(T, IntroducerRange,
+                              CaptureDefault, CaptureDefaultLoc, Captures,
+                              ExplicitParams, ExplicitResultType,
                               CaptureInits, ArrayIndexVars, ArrayIndexStarts,
                               ClosingBrace, ContainsUnexpandedParameterPack);
 }
diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 8351ff27869..ae3a938333f 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -180,6 +180,7 @@ CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
 LambdaScopeInfo *Sema::enterLambdaScope(CXXMethodDecl *CallOperator,
                                         SourceRange IntroducerRange,
                                         LambdaCaptureDefault CaptureDefault,
+                                        SourceLocation CaptureDefaultLoc,
                                         bool ExplicitParams,
                                         bool ExplicitResultType,
                                         bool Mutable) {
@@ -189,6 +190,7 @@ LambdaScopeInfo *Sema::enterLambdaScope(CXXMethodDecl *CallOperator,
     LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval;
   else if (CaptureDefault == LCD_ByRef)
     LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref;
+  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
   LSI->IntroducerRange = IntroducerRange;
   LSI->ExplicitParams = ExplicitParams;
   LSI->Mutable = Mutable;
@@ -598,7 +600,10 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
     
   // Introduce the lambda scope.
   LambdaScopeInfo *LSI
-    = enterLambdaScope(Method, Intro.Range, Intro.Default, ExplicitParams,
+    = enterLambdaScope(Method,
+                       Intro.Range,
+                       Intro.Default, Intro.DefaultLoc,
+                       ExplicitParams,
                        ExplicitResultType,
                        !Method->isConst());
 
@@ -919,6 +924,7 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
   SmallVector<LambdaExpr::Capture, 4> Captures;
   SmallVector<Expr *, 4> CaptureInits;
   LambdaCaptureDefault CaptureDefault;
+  SourceLocation CaptureDefaultLoc;
   CXXRecordDecl *Class;
   CXXMethodDecl *CallOperator;
   SourceRange IntroducerRange;
@@ -988,6 +994,7 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
       llvm_unreachable("block capture in lambda");
       break;
     }
+    CaptureDefaultLoc = LSI->CaptureDefaultLoc;
 
     // C++11 [expr.prim.lambda]p4:
     //   If a lambda-expression does not include a
@@ -1052,7 +1059,8 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
     ExprNeedsCleanups = true;
   
   LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange, 
-                                          CaptureDefault, Captures, 
+                                          CaptureDefault, CaptureDefaultLoc,
+                                          Captures, 
                                           ExplicitParams, ExplicitResultType,
                                           CaptureInits, ArrayIndexVars, 
                                           ArrayIndexStarts, Body->getLocEnd(),
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index ca0b9ad68ab..9cd13b2524c 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -8254,6 +8254,7 @@ TreeTransform<Derived>::TransformLambdaScope(LambdaExpr *E,
   sema::LambdaScopeInfo *LSI
     = getSema().enterLambdaScope(CallOperator, E->getIntroducerRange(),
                                  E->getCaptureDefault(),
+                                 E->getCaptureDefaultLoc(),
                                  E->hasExplicitParameters(),
                                  E->hasExplicitResultType(),
                                  E->isMutable());
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 8cf4bae8990..c0193c37726 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -1207,6 +1207,7 @@ void ASTStmtReader::VisitLambdaExpr(LambdaExpr *E) {
   unsigned NumArrayIndexVars = Record[Idx++];
   E->IntroducerRange = ReadSourceRange(Record, Idx);
   E->CaptureDefault = static_cast<LambdaCaptureDefault>(Record[Idx++]);
+  E->CaptureDefaultLoc = ReadSourceLocation(Record, Idx);
   E->ExplicitParams = Record[Idx++];
   E->ExplicitResultType = Record[Idx++];
   E->ClosingBrace = ReadSourceLocation(Record, Idx);
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index d8b852136c9..533496d5dc4 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -6,9 +6,10 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-//  This file implements serialization for Statements and Expressions.
-//
+///
+/// \file
+/// \brief Implements serialization for Statements and Expressions.
+///
 //===----------------------------------------------------------------------===//
 
 #include "clang/Serialization/ASTWriter.h"
@@ -1166,6 +1167,7 @@ void ASTStmtWriter::VisitLambdaExpr(LambdaExpr *E) {
   Record.push_back(NumArrayIndexVars);
   Writer.AddSourceRange(E->IntroducerRange, Record);
   Record.push_back(E->CaptureDefault); // FIXME: stable encoding
+  Writer.AddSourceLocation(E->CaptureDefaultLoc, Record);
   Record.push_back(E->ExplicitParams);
   Record.push_back(E->ExplicitResultType);
   Writer.AddSourceLocation(E->ClosingBrace, Record);