Move the maintenance of CXXRecordDecl::DefinitionData's Abstract bit

completely into CXXRecordDecl, by adding a new completeDefinition()
function. This required a little reshuffling of the final-overrider
checking code, since the "abstract" calculation in the presence of
abstract base classes needs to occur in
CXXRecordDecl::completeDefinition() but we don't want to compute final
overriders more than one in the common case.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@115007 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 117 insertions, 77 deletions

diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index 036292b6a5..6e879ee9ee 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -14,6 +14,7 @@
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/CXXInheritance.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/TypeLoc.h"
 #include "clang/Basic/IdentifierTable.h"
@@ -794,6 +795,63 @@ CXXDestructorDecl *CXXRecordDecl::getDestructor() const {
   return Dtor;
 }
 
+void CXXRecordDecl::completeDefinition() {
+  completeDefinition(0);
+}
+
+void CXXRecordDecl::completeDefinition(CXXFinalOverriderMap *FinalOverriders) {
+  RecordDecl::completeDefinition();
+  
+  // If the class may be abstract (but hasn't been marked as such), check for
+  // any pure final overriders.
+  if (mayBeAbstract()) {
+    CXXFinalOverriderMap MyFinalOverriders;
+    if (!FinalOverriders) {
+      getFinalOverriders(MyFinalOverriders);
+      FinalOverriders = &MyFinalOverriders;
+    }
+    
+    bool Done = false;
+    for (CXXFinalOverriderMap::iterator M = FinalOverriders->begin(), 
+                                     MEnd = FinalOverriders->end();
+         M != MEnd && !Done; ++M) {
+      for (OverridingMethods::iterator SO = M->second.begin(), 
+                                    SOEnd = M->second.end();
+           SO != SOEnd && !Done; ++SO) {
+        assert(SO->second.size() > 0 && 
+               "All virtual functions have overridding virtual functions");
+        
+        // C++ [class.abstract]p4:
+        //   A class is abstract if it contains or inherits at least one
+        //   pure virtual function for which the final overrider is pure
+        //   virtual.
+        if (SO->second.front().Method->isPure()) {
+          data().Abstract = true;
+          Done = true;
+          break;
+        }
+      }
+    }
+  }
+}
+
+bool CXXRecordDecl::mayBeAbstract() const {
+  if (data().Abstract || isInvalidDecl() || !data().Polymorphic ||
+      isDependentContext())
+    return false;
+  
+  for (CXXRecordDecl::base_class_const_iterator B = bases_begin(),
+                                             BEnd = bases_end();
+       B != BEnd; ++B) {
+    CXXRecordDecl *BaseDecl 
+      = cast<CXXRecordDecl>(B->getType()->getAs<RecordType>()->getDecl());
+    if (BaseDecl->isAbstract())
+      return true;
+  }
+  
+  return false;
+}
+
 CXXMethodDecl *
 CXXMethodDecl::Create(ASTContext &C, CXXRecordDecl *RD,
                       const DeclarationNameInfo &NameInfo,
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 871cb9fd78..7902ce84b5 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -6692,7 +6692,64 @@ void Sema::ActOnFields(Scope* S,
 
   // Okay, we successfully defined 'Record'.
   if (Record) {
-    Record->completeDefinition();
+    bool Completed = false;
+    if (CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(Record)) {
+      if (!CXXRecord->isInvalidDecl()) {
+        // Set access bits correctly on the directly-declared conversions.
+        UnresolvedSetImpl *Convs = CXXRecord->getConversionFunctions();
+        for (UnresolvedSetIterator I = Convs->begin(), E = Convs->end(); 
+             I != E; ++I)
+          Convs->setAccess(I, (*I)->getAccess());
+        
+        if (!CXXRecord->isDependentType()) {
+          // Add any implicitly-declared members to this class.
+          AddImplicitlyDeclaredMembersToClass(CXXRecord);
+
+          // If we have virtual base classes, we may end up finding multiple 
+          // final overriders for a given virtual function. Check for this 
+          // problem now.
+          if (CXXRecord->getNumVBases()) {
+            CXXFinalOverriderMap FinalOverriders;
+            CXXRecord->getFinalOverriders(FinalOverriders);
+            
+            for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(), 
+                                             MEnd = FinalOverriders.end();
+                 M != MEnd; ++M) {
+              for (OverridingMethods::iterator SO = M->second.begin(), 
+                                            SOEnd = M->second.end();
+                   SO != SOEnd; ++SO) {
+                assert(SO->second.size() > 0 && 
+                       "Virtual function without overridding functions?");
+                if (SO->second.size() == 1)
+                  continue;
+                
+                // C++ [class.virtual]p2:
+                //   In a derived class, if a virtual member function of a base
+                //   class subobject has more than one final overrider the
+                //   program is ill-formed.
+                Diag(Record->getLocation(), diag::err_multiple_final_overriders)
+                  << (NamedDecl *)M->first << Record;
+                Diag(M->first->getLocation(), 
+                     diag::note_overridden_virtual_function);
+                for (OverridingMethods::overriding_iterator 
+                          OM = SO->second.begin(), 
+                       OMEnd = SO->second.end();
+                     OM != OMEnd; ++OM)
+                  Diag(OM->Method->getLocation(), diag::note_final_overrider)
+                    << (NamedDecl *)M->first << OM->Method->getParent();
+                
+                Record->setInvalidDecl();
+              }
+            }
+            CXXRecord->completeDefinition(&FinalOverriders);
+            Completed = true;
+          }
+        }
+      }
+    }
+    
+    if (!Completed)
+      Record->completeDefinition();
   } else {
     ObjCIvarDecl **ClsFields =
       reinterpret_cast<ObjCIvarDecl**>(RecFields.data());
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 425389a6b4..e0049e636f 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -2505,84 +2505,9 @@ static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
 /// completing, introducing implicitly-declared members, checking for
 /// abstract types, etc.
 void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) {
-  if (!Record || Record->isInvalidDecl())
+  if (!Record)
     return;
 
-  if (!Record->isDependentType())
-    AddImplicitlyDeclaredMembersToClass(Record);
-  
-  if (Record->isInvalidDecl())
-    return;
-
-  // Set access bits correctly on the directly-declared conversions.
-  UnresolvedSetImpl *Convs = Record->getConversionFunctions();
-  for (UnresolvedSetIterator I = Convs->begin(), E = Convs->end(); I != E; ++I)
-    Convs->setAccess(I, (*I)->getAccess());
-
-  // Determine whether we need to check for final overriders. We do
-  // this either when there are virtual base classes (in which case we
-  // may end up finding multiple final overriders for a given virtual
-  // function) or any of the base classes is abstract (in which case
-  // we might detect that this class is abstract).
-  bool CheckFinalOverriders = false;
-  if (Record->isPolymorphic() && !Record->isInvalidDecl() &&
-      !Record->isDependentType()) {
-    if (Record->getNumVBases())
-      CheckFinalOverriders = true;
-    else if (!Record->isAbstract()) {
-      for (CXXRecordDecl::base_class_const_iterator B = Record->bases_begin(),
-                                                 BEnd = Record->bases_end();
-           B != BEnd; ++B) {
-        CXXRecordDecl *BaseDecl 
-          = cast<CXXRecordDecl>(B->getType()->getAs<RecordType>()->getDecl());
-        if (BaseDecl->isAbstract()) {
-          CheckFinalOverriders = true; 
-          break;
-        }
-      }
-    }
-  }
-
-  if (CheckFinalOverriders) {
-    CXXFinalOverriderMap FinalOverriders;
-    Record->getFinalOverriders(FinalOverriders);
-
-    for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(), 
-                                     MEnd = FinalOverriders.end();
-         M != MEnd; ++M) {
-      for (OverridingMethods::iterator SO = M->second.begin(), 
-                                    SOEnd = M->second.end();
-           SO != SOEnd; ++SO) {
-        assert(SO->second.size() > 0 && 
-               "All virtual functions have overridding virtual functions");
-        if (SO->second.size() == 1) {
-          // C++ [class.abstract]p4:
-          //   A class is abstract if it contains or inherits at least one
-          //   pure virtual function for which the final overrider is pure
-          //   virtual.
-          if (SO->second.front().Method->isPure())
-            Record->setAbstract(true);
-          continue;
-        }
-
-        // C++ [class.virtual]p2:
-        //   In a derived class, if a virtual member function of a base
-        //   class subobject has more than one final overrider the
-        //   program is ill-formed.
-        Diag(Record->getLocation(), diag::err_multiple_final_overriders)
-          << (NamedDecl *)M->first << Record;
-        Diag(M->first->getLocation(), diag::note_overridden_virtual_function);
-        for (OverridingMethods::overriding_iterator OM = SO->second.begin(), 
-                                                 OMEnd = SO->second.end();
-             OM != OMEnd; ++OM)
-          Diag(OM->Method->getLocation(), diag::note_final_overrider)
-            << (NamedDecl *)M->first << OM->Method->getParent();
-        
-        Record->setInvalidDecl();
-      }
-    }
-  }
-
   if (Record->isAbstract() && !Record->isInvalidDecl()) {
     AbstractUsageInfo Info(*this, Record);
     CheckAbstractClassUsage(Info, Record);