From: John McCall <rjmccall@apple.com>
Date: Wed, 6 Jul 2011 06:57:57 +0000 (+0000)
Subject: Fixed enum types can be complete without actually being valid to use
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9dc71d2fddcd283e07d45f3894c8559e2f7dd9a7;p=clang

Fixed enum types can be complete without actually being valid to use
as scope specifiers;  diagnose the attempt, rather than letting it go
to an assert.  The rest of PR10264.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134479 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/AST/NestedNameSpecifier.h b/include/clang/AST/NestedNameSpecifier.h
index 5deefe9d97..018041f8ba 100644
--- a/include/clang/AST/NestedNameSpecifier.h
+++ b/include/clang/AST/NestedNameSpecifier.h
@@ -439,6 +439,14 @@ public:
   /// copied.
   NestedNameSpecifierLoc getWithLocInContext(ASTContext &Context) const;
 
+  /// \brief Retrieve a nested-name-specifier with location
+  /// information based on the information in this builder.  This loc
+  /// will contain references to the builder's internal data and may
+  /// be invalidated by any change to the builder.
+  NestedNameSpecifierLoc getTemporary() const {
+    return NestedNameSpecifierLoc(Representation, Buffer);
+  }
+
   /// \brief Clear out this builder, and prepare it to build another
   /// nested-name-specifier with source-location information.
   void Clear() {
diff --git a/include/clang/Sema/DeclSpec.h b/include/clang/Sema/DeclSpec.h
index db811d06f2..e3bc5bff57 100644
--- a/include/clang/Sema/DeclSpec.h
+++ b/include/clang/Sema/DeclSpec.h
@@ -154,6 +154,12 @@ public:
   /// copied.
   NestedNameSpecifierLoc getWithLocInContext(ASTContext &Context) const;
 
+  /// \brief Retrieve the location of the name in the last qualifier
+  /// in this nested name specifier.  For example:
+  ///   ::foo::bar<0>::
+  ///          ^~~
+  SourceLocation getLastQualifierNameLoc() const;
+
   /// No scope specifier.
   bool isEmpty() const { return !Range.isValid(); }
   /// A scope specifier is present, but may be valid or invalid.
diff --git a/lib/Sema/DeclSpec.cpp b/lib/Sema/DeclSpec.cpp
index c5b883e46d..a61188c3c4 100644
--- a/lib/Sema/DeclSpec.cpp
+++ b/lib/Sema/DeclSpec.cpp
@@ -126,6 +126,12 @@ void CXXScopeSpec::Adopt(NestedNameSpecifierLoc Other) {
   Builder.Adopt(Other);
 }
 
+SourceLocation CXXScopeSpec::getLastQualifierNameLoc() const {
+  if (!Builder.getRepresentation())
+    return SourceLocation();
+  return Builder.getTemporary().getLocalBeginLoc();
+}
+
 NestedNameSpecifierLoc 
 CXXScopeSpec::getWithLocInContext(ASTContext &Context) const {
   if (!Builder.getRepresentation())
diff --git a/lib/Sema/SemaCXXScopeSpec.cpp b/lib/Sema/SemaCXXScopeSpec.cpp
index e54857196a..5f8c9c62a4 100644
--- a/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/lib/Sema/SemaCXXScopeSpec.cpp
@@ -211,25 +211,40 @@ bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS,
                                       DeclContext *DC) {
   assert(DC != 0 && "given null context");
 
-  if (TagDecl *Tag = dyn_cast<TagDecl>(DC)) {
+  if (TagDecl *tag = dyn_cast<TagDecl>(DC)) {
     // If this is a dependent type, then we consider it complete.
-    if (Tag->isDependentContext())
+    if (tag->isDependentContext())
       return false;
 
     // If we're currently defining this type, then lookup into the
     // type is okay: don't complain that it isn't complete yet.
-    const TagType *TagT = Context.getTypeDeclType(Tag)->getAs<TagType>();
-    if (TagT && TagT->isBeingDefined())
+    QualType type = Context.getTypeDeclType(tag);
+    const TagType *tagType = type->getAs<TagType>();
+    if (tagType && tagType->isBeingDefined())
       return false;
 
+    SourceLocation loc = SS.getLastQualifierNameLoc();
+    if (loc.isInvalid()) loc = SS.getRange().getBegin();
+
     // The type must be complete.
-    if (RequireCompleteType(SS.getRange().getBegin(),
-                            Context.getTypeDeclType(Tag),
+    if (RequireCompleteType(loc, type,
                             PDiag(diag::err_incomplete_nested_name_spec)
                               << SS.getRange())) {
       SS.SetInvalid(SS.getRange());
       return true;
     }
+
+    // Fixed enum types are complete, but they aren't valid as scopes
+    // until we see a definition, so awkwardly pull out this special
+    // case.
+    if (const EnumType *enumType = dyn_cast_or_null<EnumType>(tagType)) {
+      if (!enumType->getDecl()->isDefinition()) {
+        Diag(loc, diag::err_incomplete_nested_name_spec)
+          << type << SS.getRange();
+        SS.SetInvalid(SS.getRange());
+        return true;
+      }
+    }
   }
 
   return false;
diff --git a/test/SemaCXX/enum-scoped.cpp b/test/SemaCXX/enum-scoped.cpp
index 2c3537e163..73e7578ecb 100644
--- a/test/SemaCXX/enum-scoped.cpp
+++ b/test/SemaCXX/enum-scoped.cpp
@@ -120,7 +120,7 @@ namespace rdar9366066 {
   }
 }
 
-// Part of PR10264
+// Part 1 of PR10264
 namespace test5 {
   namespace ns {
     typedef unsigned Atype;
@@ -130,3 +130,15 @@ namespace test5 {
     x, y, z
   };
 }
+
+// Part 2 of PR10264
+namespace test6 {
+  enum A : unsigned;
+  struct A::a; // expected-error {{incomplete type 'test6::A' named in nested name specifier}}
+  enum A::b; // expected-error {{incomplete type 'test6::A' named in nested name specifier}}
+  int A::c; // expected-error {{incomplete type 'test6::A' named in nested name specifier}}
+  void A::d(); // expected-error {{incomplete type 'test6::A' named in nested name specifier}}
+  void test() {
+    (void) A::e; // expected-error {{incomplete type 'test6::A' named in nested name specifier}}
+  }
+}