Make it possible to compute the type of 'this' without capturing

it. Refactoring to be used in a moment.

llvm-svn: 142360

clang/include/clang/Sema/Sema.h

@@ -3019,9 +3019,12 @@ public:
   //// ActOnCXXThis -  Parse 'this' pointer.
   ExprResult ActOnCXXThis(SourceLocation loc);
 
-  /// getAndCaptureCurrentThisType - Try to capture a 'this' pointer.  Returns
-  /// the type of the 'this' pointer, or a null type if this is not possible.
-  QualType getAndCaptureCurrentThisType();
+  /// \brief Try to retrieve the type of the 'this' pointer.
+  ///
+  /// \param Capture If true, capture 'this' in this context.
+  ///
+  /// \returns The type of 'this', if possible. Otherwise, returns a NULL type.
+  QualType getCurrentThisType(bool Capture = true);
 
   /// ActOnCXXBoolLiteral - Parse {true,false} literals.
   ExprResult ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind);

clang/lib/Sema/SemaExprCXX.cpp

@@ -636,7 +636,7 @@ ExprResult Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E,
   return Owned(E);
 }
 
-QualType Sema::getAndCaptureCurrentThisType() {
+QualType Sema::getCurrentThisType(bool Capture) {
   // Ignore block scopes: we can capture through them.
   // Ignore nested enum scopes: we'll diagnose non-constant expressions
   // where they're invalid, and other uses are legitimate.
@@ -666,11 +666,13 @@ QualType Sema::getAndCaptureCurrentThisType() {
       ThisTy = Context.getPointerType(Context.getRecordType(RD));
   }
 
+  if (!Capture || ThisTy.isNull())
+    return ThisTy;
+  
   // Mark that we're closing on 'this' in all the block scopes we ignored.
-  if (!ThisTy.isNull())
-    for (unsigned idx = FunctionScopes.size() - 1;
-         NumBlocks; --idx, --NumBlocks)
-      cast<BlockScopeInfo>(FunctionScopes[idx])->CapturesCXXThis = true;
+  for (unsigned idx = FunctionScopes.size() - 1;
+       NumBlocks; --idx, --NumBlocks)
+    cast<BlockScopeInfo>(FunctionScopes[idx])->CapturesCXXThis = true;
 
   return ThisTy;
 }
@@ -680,7 +682,7 @@ ExprResult Sema::ActOnCXXThis(SourceLocation Loc) {
   /// is a non-lvalue expression whose value is the address of the object for
   /// which the function is called.
 
-  QualType ThisTy = getAndCaptureCurrentThisType();
+  QualType ThisTy = getCurrentThisType();
   if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use);
 
   return Owned(new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false));

clang/lib/Sema/SemaExprMember.cpp

@@ -697,7 +697,7 @@ Sema::BuildAnonymousStructUnionMemberReference(const CXXScopeSpec &SS,
     // We've found a member of an anonymous struct/union that is
     // inside a non-anonymous struct/union, so in a well-formed
     // program our base object expression is "this".
-    QualType ThisTy = getAndCaptureCurrentThisType();
+    QualType ThisTy = getCurrentThisType();
     if (ThisTy.isNull()) {
       Diag(loc, diag::err_invalid_member_use_in_static_method)
         << indirectField->getDeclName();
@@ -1569,7 +1569,7 @@ Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS,
   // If this is known to be an instance access, go ahead and build an
   // implicit 'this' expression now.
   // 'this' expression now.
-  QualType ThisTy = getAndCaptureCurrentThisType();
+  QualType ThisTy = getCurrentThisType();
   assert(!ThisTy.isNull() && "didn't correctly pre-flight capture of 'this'");
   
   Expr *baseExpr = 0; // null signifies implicit access