Diagnose declspecs occuring after virt-specifier-seq and generate fixit hints

Summary: This fixes PR22075.

Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D6828

llvm-svn: 233160

3 files changed, 55 insertions, 2 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index b4a76642981..c19759e596c 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -5329,7 +5329,7 @@ void Parser::ParseFunctionDeclarator(Declarator &D,
     if (getLangOpts().CPlusPlus) {
       // FIXME: Accept these components in any order, and produce fixits to
       // correct the order if the user gets it wrong. Ideally we should deal
-      // with the virt-specifier-seq and pure-specifier in the same way.
+      // with the pure-specifier in the same way.
 
       // Parse cv-qualifier-seq[opt].
       ParseTypeQualifierListOpt(DS, AR_NoAttributesParsed,
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 3403cdea7ae..aac7d630954 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -2037,10 +2037,13 @@ bool Parser::ParseCXXMemberDeclaratorBeforeInitializer(
     BitfieldSize = ParseConstantExpression();
     if (BitfieldSize.isInvalid())
       SkipUntil(tok::comma, StopAtSemi | StopBeforeMatch);
-  } else
+  } else {
     ParseOptionalCXX11VirtSpecifierSeq(
         VS, getCurrentClass().IsInterface,
         DeclaratorInfo.getDeclSpec().getFriendSpecLoc());
+    if (!VS.isUnset())
+      MaybeParseAndDiagnoseDeclSpecAfterCXX11VirtSpecifierSeq(DeclaratorInfo, VS);
+  }
 
   // If a simple-asm-expr is present, parse it.
   if (Tok.is(tok::kw_asm)) {
@@ -2071,6 +2074,7 @@ bool Parser::ParseCXXMemberDeclaratorBeforeInitializer(
           Diag(Attr->getLoc(), diag::warn_gcc_attribute_location);
         Attr = Attr->getNext();
       }
+      MaybeParseAndDiagnoseDeclSpecAfterCXX11VirtSpecifierSeq(DeclaratorInfo, VS);
     }
   }
 
@@ -2084,6 +2088,52 @@ bool Parser::ParseCXXMemberDeclaratorBeforeInitializer(
   return false;
 }
 
+/// \brief Look for declaration specifiers possibly occurring after C++11
+/// virt-specifier-seq and diagnose them.
+void Parser::MaybeParseAndDiagnoseDeclSpecAfterCXX11VirtSpecifierSeq(
+    Declarator &D,
+    VirtSpecifiers &VS) {
+  DeclSpec DS(AttrFactory);
+
+  // GNU-style and C++11 attributes are not allowed here, but they will be
+  // handled by the caller.  Diagnose everything else.
+  ParseTypeQualifierListOpt(DS, AR_NoAttributesParsed, false);
+  D.ExtendWithDeclSpec(DS);
+
+  if (D.isFunctionDeclarator()) {
+    if (DS.getTypeQualifiers() != DeclSpec::TQ_unspecified) {
+      auto DeclSpecCheck = [&] (DeclSpec::TQ TypeQual,
+                                const char *FixItName,
+                                SourceLocation SpecLoc,
+                                unsigned* QualifierLoc) {
+        FixItHint Insertion;
+        auto &Function = D.getFunctionTypeInfo();
+        if (DS.getTypeQualifiers() & TypeQual) {
+          if (!(Function.TypeQuals & TypeQual)) {
+            std::string Name(FixItName);
+            Name += " ";
+            Insertion = FixItHint::CreateInsertion(VS.getFirstLocation(), Name.c_str());
+            Function.TypeQuals |= TypeQual;
+            *QualifierLoc = SpecLoc.getRawEncoding();
+          }
+          Diag(SpecLoc, diag::err_declspec_after_virtspec)
+            << FixItName
+            << VirtSpecifiers::getSpecifierName(VS.getLastSpecifier())
+            << FixItHint::CreateRemoval(SpecLoc)
+            << Insertion;
+        }
+      };
+      auto &Function = D.getFunctionTypeInfo();
+      DeclSpecCheck(DeclSpec::TQ_const, "const", DS.getConstSpecLoc(),
+                    &Function.ConstQualifierLoc);
+      DeclSpecCheck(DeclSpec::TQ_volatile, "volatile", DS.getVolatileSpecLoc(),
+                    &Function.VolatileQualifierLoc);
+      DeclSpecCheck(DeclSpec::TQ_restrict, "restrict", DS.getRestrictSpecLoc(),
+                    &Function.RestrictQualifierLoc);
+    }
+  }
+}
+
 /// ParseCXXClassMemberDeclaration - Parse a C++ class member declaration.
 ///
 ///       member-declaration:
diff --git a/clang/lib/Sema/DeclSpec.cpp b/clang/lib/Sema/DeclSpec.cpp
index 5e349bc2ad2..f6689a96bdc 100644
--- a/clang/lib/Sema/DeclSpec.cpp
+++ b/clang/lib/Sema/DeclSpec.cpp
@@ -1220,7 +1220,10 @@ void UnqualifiedId::setOperatorFunctionId(SourceLocation OperatorLoc,
 
 bool VirtSpecifiers::SetSpecifier(Specifier VS, SourceLocation Loc,
                                   const char *&PrevSpec) {
+  if (!FirstLocation.isValid())
+    FirstLocation = Loc;
   LastLocation = Loc;
+  LastSpecifier = VS;
   
   if (Specifiers & VS) {
     PrevSpec = getSpecifierName(VS);