r224912 - Sema: Don't crash when solitary :: token appears before { in struct def

[David Majnemer]

Perhaps something like the following?

diff --git a/include/clang/Basic/DiagnosticParseKinds.td
b/include/clang/Basic/DiagnosticParseKinds.td
index f39c2b8..f176370 100644
--- a/include/clang/Basic/DiagnosticParseKinds.td
+++ b/include/clang/Basic/DiagnosticParseKinds.td
@@ -374,6 +374,8 @@ def warn_cxx98_compat_static_assert : Warning<
   InGroup<CXX98Compat>, DefaultIgnore;
 def err_paren_after_colon_colon : Error<
   "unexpected parenthesis after '::'">;
+def err_brace_after_colon_colon : Error<
+  "unexpected brace after '::'">;
 def err_function_definition_not_allowed : Error<
   "function definition is not allowed here">;
 def err_expected_end_of_enumerator : Error<
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index dad1f0d..7968a01 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -219,13 +219,20 @@ bool
Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
     if (NextKind == tok::kw_new || NextKind == tok::kw_delete)
       return false;

-    // '::' - Global scope qualifier.
-    if (Actions.ActOnCXXGlobalScopeSpecifier(ConsumeToken(), SS))
-      return true;
+    if (NextKind == tok::l_brace) {
+      // It is invalid to have :: {, consume the scope qualifier and
pretend
+      // like we never saw it.
+      SourceLocation ColonColonLoc = ConsumeToken();
+      Diag(ColonColonLoc, diag::err_brace_after_colon_colon);
+    } else {
+      // '::' - Global scope qualifier.
+      if (Actions.ActOnCXXGlobalScopeSpecifier(ConsumeToken(), SS))
+        return true;

-    CheckForLParenAfterColonColon();
+      CheckForLParenAfterColonColon();

-    HasScopeSpecifier = true;
+      HasScopeSpecifier = true;
+    }
   }

   if (Tok.is(tok::kw___super)) {

On Mon, Dec 29, 2014 at 12:53 AM, Richard Smith <richard at metafoo.co.uk>
wrote:

> Perhaps we should drop the qualifier in the parser in this case; this
> doesn't match the grammar and it doesn't make a lot of sense to propagate
> this weird broken state all the way into the AST.
> On 29 Dec 2014 05:21, "David Majnemer" <david.majnemer at gmail.com> wrote:
>
>> Author: majnemer
>> Date: Sun Dec 28 23:17:46 2014
>> New Revision: 224912
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=224912&view=rev
>> Log:
>> Sema: Don't crash when solitary :: token appears before { in struct def
>>
>> hasDeclaratorForAnonDecl, getDeclaratorForAnonDecl and
>> getTypedefNameForAnonDecl are expected to handle the case where
>> NamedDeclOrQualifier holds the wrong type or nothing at all.
>>
>> Modified:
>>     cfe/trunk/include/clang/AST/Decl.h
>>     cfe/trunk/lib/Sema/SemaDecl.cpp
>>     cfe/trunk/test/CXX/dcl.decl/dcl.meaning/p1.cpp
>>
>> Modified: cfe/trunk/include/clang/AST/Decl.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Decl.h?rev=224912&r1=224911&r2=224912&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/include/clang/AST/Decl.h (original)
>> +++ cfe/trunk/include/clang/AST/Decl.h Sun Dec 28 23:17:46 2014
>> @@ -2823,16 +2823,18 @@ public:
>>
>>    bool hasDeclaratorForAnonDecl() const {
>>      return dyn_cast_or_null<DeclaratorDecl>(
>> -        NamedDeclOrQualifier.get<NamedDecl *>());
>> +        NamedDeclOrQualifier.dyn_cast<NamedDecl *>());
>>    }
>>    DeclaratorDecl *getDeclaratorForAnonDecl() const {
>> -    return hasExtInfo() ? nullptr : dyn_cast_or_null<DeclaratorDecl>(
>> -                                  NamedDeclOrQualifier.get<NamedDecl
>> *>());
>> +    return hasExtInfo() ? nullptr
>> +                        : dyn_cast_or_null<DeclaratorDecl>(
>> +                              NamedDeclOrQualifier.dyn_cast<NamedDecl
>> *>());
>>    }
>>
>>    TypedefNameDecl *getTypedefNameForAnonDecl() const {
>> -    return hasExtInfo() ? nullptr : dyn_cast_or_null<TypedefNameDecl>(
>> -                                  NamedDeclOrQualifier.get<NamedDecl
>> *>());
>> +    return hasExtInfo() ? nullptr
>> +                        : dyn_cast_or_null<TypedefNameDecl>(
>> +                              NamedDeclOrQualifier.dyn_cast<NamedDecl
>> *>());
>>    }
>>
>>    void setDeclaratorForAnonDecl(DeclaratorDecl *DD) {
>> NamedDeclOrQualifier = DD; }
>>
>> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=224912&r1=224911&r2=224912&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Sun Dec 28 23:17:46 2014
>> @@ -11790,7 +11790,7 @@ CreateNewDecl:
>>        // CheckMemberSpecialization, below.
>>        if (!isExplicitSpecialization &&
>>            (TUK == TUK_Definition || TUK == TUK_Declaration) &&
>> -          diagnoseQualifiedDeclaration(SS, DC, OrigName, NameLoc))
>> +          diagnoseQualifiedDeclaration(SS, DC, OrigName, Loc))
>>          Invalid = true;
>>
>>        New->setQualifierInfo(SS.getWithLocInContext(Context));
>>
>> Modified: cfe/trunk/test/CXX/dcl.decl/dcl.meaning/p1.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.decl/dcl.meaning/p1.cpp?rev=224912&r1=224911&r2=224912&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/test/CXX/dcl.decl/dcl.meaning/p1.cpp (original)
>> +++ cfe/trunk/test/CXX/dcl.decl/dcl.meaning/p1.cpp Sun Dec 28 23:17:46
>> 2014
>> @@ -43,3 +43,6 @@ namespace NS {
>>    template<typename T> struct NS::Y { }; // expected-warning{{extra
>> qualification on member 'Y'}}
>>    template<typename T> void NS::wibble(T) { } // expected-warning{{extra
>> qualification on member 'wibble'}}
>>  }
>> +
>> +// expected-warning at +1{{extra qualification on member}}
>> +struct ::{} a; // expected-error{{expected identifier}}
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>>
>
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