From cccd06487d473f2ede4fde7f869c4a85943a082b Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Tue, 16 Jul 2013 00:01:31 +0000
Subject: Fix member refs with using decl + anonymous union.

Make sure we call BuildFieldReferenceExpr with the appropriate decl
when a member of an anonymous union is made public with a using decl.
Also, fix a crash on invalid field access into an anonymous union.

Fixes PR16630.

llvm-svn: 186367
---
 clang/lib/Sema/SemaExprMember.cpp | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

(limited to 'clang/lib/Sema/SemaExprMember.cpp')

diff --git a/clang/lib/Sema/SemaExprMember.cpp b/clang/lib/Sema/SemaExprMember.cpp
index 7151fc55041..29e91e173df 100644
--- a/clang/lib/Sema/SemaExprMember.cpp
+++ b/clang/lib/Sema/SemaExprMember.cpp
@@ -703,6 +703,7 @@ ExprResult
 Sema::BuildAnonymousStructUnionMemberReference(const CXXScopeSpec &SS,
                                                SourceLocation loc,
                                                IndirectFieldDecl *indirectField,
+                                               DeclAccessPair foundDecl,
                                                Expr *baseObjectExpr,
                                                SourceLocation opLoc) {
   // First, build the expression that refers to the base object.
@@ -780,15 +781,15 @@ Sema::BuildAnonymousStructUnionMemberReference(const CXXScopeSpec &SS,
   if (!baseVariable) {
     FieldDecl *field = cast<FieldDecl>(*FI);
     
-    // FIXME: use the real found-decl info!
-    DeclAccessPair foundDecl = DeclAccessPair::make(field, field->getAccess());
-    
     // Make a nameInfo that properly uses the anonymous name.
     DeclarationNameInfo memberNameInfo(field->getDeclName(), loc);
     
     result = BuildFieldReferenceExpr(*this, result, baseObjectIsPointer,
                                      EmptySS, field, foundDecl,
                                      memberNameInfo).take();
+    if (!result)
+      return ExprError();
+
     baseObjectIsPointer = false;
     
     // FIXME: check qualified member access
@@ -799,14 +800,15 @@ Sema::BuildAnonymousStructUnionMemberReference(const CXXScopeSpec &SS,
   
   while (FI != FEnd) {
     FieldDecl *field = cast<FieldDecl>(*FI++);
-    
+
     // FIXME: these are somewhat meaningless
     DeclarationNameInfo memberNameInfo(field->getDeclName(), loc);
-    DeclAccessPair foundDecl = DeclAccessPair::make(field, field->getAccess());
-    
+    DeclAccessPair fakeFoundDecl =
+        DeclAccessPair::make(field, field->getAccess());
+
     result = BuildFieldReferenceExpr(*this, result, /*isarrow*/ false,
-                                     (FI == FEnd? SS : EmptySS), field, 
-                                     foundDecl, memberNameInfo).take();
+                                     (FI == FEnd? SS : EmptySS), field,
+                                     fakeFoundDecl, memberNameInfo).take();
   }
   
   return Owned(result);
@@ -990,7 +992,8 @@ Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType,
     // We may have found a field within an anonymous union or struct
     // (C++ [class.union]).
     return BuildAnonymousStructUnionMemberReference(SS, MemberLoc, FD,
-                                                    BaseExpr, OpLoc);
+                                                    FoundDecl, BaseExpr,
+                                                    OpLoc);
 
   if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) {
     return Owned(BuildMemberExpr(*this, Context, BaseExpr, IsArrow, SS,
@@ -1688,7 +1691,8 @@ Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS,
   // (C++ [class.union]).
   // FIXME: template-ids inside anonymous structs?
   if (IndirectFieldDecl *FD = R.getAsSingle<IndirectFieldDecl>())
-    return BuildAnonymousStructUnionMemberReference(SS, R.getNameLoc(), FD);
+    return BuildAnonymousStructUnionMemberReference(SS, R.getNameLoc(), FD,
+                                                    R.begin().getPair());
   
   // If this is known to be an instance access, go ahead and build an
   // implicit 'this' expression now.
-- 
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