Rework parsing of pseudo-destructor expressions and explicit

destructor calls, e.g., 

  p->T::~T

We now detect when the member access that we've parsed, e.g.,

  p-> or x.

may be a pseudo-destructor expression, either because the type of p or
x is a scalar or because it is dependent (and, therefore, may become a
scalar at template instantiation time). 

We then parse the pseudo-destructor grammar specifically:

  ::[opt] nested-name-specifier[opt] type-name :: ∼ type-name

and hand those results to a new action, ActOnPseudoDestructorExpr,
which will cope with both dependent member accesses of destructors and
with pseudo-destructor expressions.

This commit affects the parsing of pseudo-destructors, only; the
semantic actions still go through the semantic actions for member
access expressions. That will change soon.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97045 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 19 insertions, 5 deletions

diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index 8105eeb875..46faebfd3f 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -996,12 +996,16 @@ Parser::ParsePostfixExpressionSuffix(OwningExprResult LHS) {
 
       CXXScopeSpec SS;
       Action::TypeTy *ObjectType = 0;
+      bool MayBePseudoDestructor = false;
       if (getLang().CPlusPlus && !LHS.isInvalid()) {
         LHS = Actions.ActOnStartCXXMemberReference(CurScope, move(LHS),
-                                                   OpLoc, OpKind, ObjectType);
+                                                   OpLoc, OpKind, ObjectType,
+                                                   MayBePseudoDestructor);
         if (LHS.isInvalid())
           break;
-        ParseOptionalCXXScopeSpecifier(SS, ObjectType, false, true);
+
+        ParseOptionalCXXScopeSpecifier(SS, ObjectType, false, 
+                                       &MayBePseudoDestructor);
       }
 
       if (Tok.is(tok::code_completion)) {
@@ -1012,6 +1016,17 @@ Parser::ParsePostfixExpressionSuffix(OwningExprResult LHS) {
         ConsumeToken();
       }
       
+      if (MayBePseudoDestructor) {
+        LHS = ParseCXXPseudoDestructor(move(LHS), OpLoc, OpKind, SS, 
+                                       ObjectType);
+        break;
+      }
+
+      // Either the action has told is that this cannot be a
+      // pseudo-destructor expression (based on the type of base
+      // expression), or we didn't see a '~' in the right place. We
+      // can still parse a destructor name here, but in that case it
+      // names a real destructor.
       UnqualifiedId Name;
       if (ParseUnqualifiedId(SS, 
                              /*EnteringContext=*/false, 
@@ -1022,10 +1037,9 @@ Parser::ParsePostfixExpressionSuffix(OwningExprResult LHS) {
         return ExprError();
       
       if (!LHS.isInvalid())
-        LHS = Actions.ActOnMemberAccessExpr(CurScope, move(LHS), OpLoc, OpKind,
-                                            SS, Name, ObjCImpDecl,
+        LHS = Actions.ActOnMemberAccessExpr(CurScope, move(LHS), OpLoc, 
+                                            OpKind, SS, Name, ObjCImpDecl,
                                             Tok.is(tok::l_paren));
-      
       break;
     }
     case tok::plusplus:    // postfix-expression: postfix-expression '++'