Revert r183298 and r183300 as the former broke the virtual function lookup in libcxx __locale

llvm-svn: 183305

1 files changed, 159 insertions, 96 deletions

diff --git a/clang/lib/AST/VTableBuilder.cpp b/clang/lib/AST/VTableBuilder.cpp
index 90285bc9b41..4f28c77b758 100644
--- a/clang/lib/AST/VTableBuilder.cpp
+++ b/clang/lib/AST/VTableBuilder.cpp
@@ -787,8 +787,6 @@ public:
   typedef llvm::DenseMap<BaseSubobject, uint64_t> 
     AddressPointsMapTy;
 
-  typedef llvm::DenseMap<GlobalDecl, int64_t> MethodVTableIndicesTy;
-
 private:
   /// VTables - Global vtable information.
   VTableContext &VTables;
@@ -861,11 +859,7 @@ private:
   /// MethodInfoMap - The information for all methods in the vtable we're
   /// currently building.
   MethodInfoMapTy MethodInfoMap;
-
-  /// MethodVTableIndices - Contains the index (relative to the vtable address
-  /// point) where the function pointer for a virtual function is stored.
-  MethodVTableIndicesTy MethodVTableIndices;
-
+  
   typedef llvm::DenseMap<uint64_t, ThunkInfo> VTableThunksMapTy;
   
   /// VTableThunks - The thunks by vtable index in the vtable currently being 
@@ -1028,14 +1022,6 @@ public:
     return AddressPoints;
   }
 
-  MethodVTableIndicesTy::const_iterator vtable_indices_begin() const {
-    return MethodVTableIndices.begin();
-  }
-
-  MethodVTableIndicesTy::const_iterator vtable_indices_end() const {
-    return MethodVTableIndices.end();
-  }
-
   /// getNumVTableComponents - Return the number of components in the vtable
   /// currently built.
   uint64_t getNumVTableComponents() const {
@@ -1451,15 +1437,6 @@ VTableBuilder::AddMethods(BaseSubobject Base, CharUnits BaseOffsetInLayoutClass,
                           const CXXRecordDecl *FirstBaseInPrimaryBaseChain,
                           CharUnits FirstBaseOffsetInLayoutClass,
                           PrimaryBasesSetVectorTy &PrimaryBases) {
-  // Itanium C++ ABI 2.5.2:
-  //   The order of the virtual function pointers in a virtual table is the
-  //   order of declaration of the corresponding member functions in the class.
-  //
-  //   There is an entry for any virtual function declared in a class,
-  //   whether it is a new function or overrides a base class function,
-  //   unless it overrides a function from the primary base, and conversion
-  //   between their return types does not require an adjustment.
-
   const CXXRecordDecl *RD = Base.getBase();
   const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
 
@@ -1497,11 +1474,6 @@ VTableBuilder::AddMethods(BaseSubobject Base, CharUnits BaseOffsetInLayoutClass,
       llvm_unreachable("Found a duplicate primary base!");
   }
 
-  const CXXDestructorDecl *ImplicitVirtualDtor = 0;
-
-  typedef llvm::SmallPtrSet<const CXXMethodDecl *, 8> NewVirtualFunctionsSetTy;
-  NewVirtualFunctionsSetTy NewVirtualFunctions;
-
   // Now go through all virtual member functions and add them.
   for (CXXRecordDecl::method_iterator I = RD->method_begin(),
        E = RD->method_end(); I != E; ++I) {
@@ -1567,33 +1539,6 @@ VTableBuilder::AddMethods(BaseSubobject Base, CharUnits BaseOffsetInLayoutClass,
       }
     }
 
-    if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
-      if (MD->isImplicit()) {
-        // Itanium C++ ABI 2.5.2:
-        //   If a class has an implicitly-defined virtual destructor,
-        //   its entries come after the declared virtual function pointers.
-
-        assert(!ImplicitVirtualDtor &&
-               "Did already see an implicit virtual dtor!");
-        ImplicitVirtualDtor = DD;
-        continue;
-      }
-    }
-
-    NewVirtualFunctions.insert(MD);
-  }
-
-  if (ImplicitVirtualDtor)
-    NewVirtualFunctions.insert(ImplicitVirtualDtor);
-
-  for (NewVirtualFunctionsSetTy::const_iterator I = NewVirtualFunctions.begin(),
-       E = NewVirtualFunctions.end(); I != E; ++I) {
-    const CXXMethodDecl *MD = *I;
-
-    // Get the final overrider.
-    FinalOverriders::OverriderInfo Overrider =
-      Overriders.getOverrider(MD, Base.getBaseOffset());
-
     // Insert the method info for this method.
     MethodInfo MethodInfo(Base.getBaseOffset(), BaseOffsetInLayoutClass,
                           Components.size());
@@ -1610,7 +1555,7 @@ VTableBuilder::AddMethods(BaseSubobject Base, CharUnits BaseOffsetInLayoutClass,
       Components.push_back(VTableComponent::MakeUnusedFunction(OverriderMD));
       continue;
     }
-
+    
     // Check if this overrider needs a return adjustment.
     // We don't want to do this for pure virtual member functions.
     BaseOffset ReturnAdjustmentOffset;
@@ -1695,34 +1640,11 @@ VTableBuilder::LayoutPrimaryAndSecondaryVTables(BaseSubobject Base,
              Base.getBase(), OffsetInLayoutClass, 
              PrimaryBases);
 
-  const CXXRecordDecl *RD = Base.getBase();
-  if (RD == MostDerivedClass) {
-    assert(MethodVTableIndices.empty());
-    for (MethodInfoMapTy::const_iterator I = MethodInfoMap.begin(),
-         E = MethodInfoMap.end(); I != E; ++I) {
-      const CXXMethodDecl *MD = I->first;
-      const MethodInfo &MI = I->second;
-      if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
-        // FIXME: Should probably add a layer of abstraction for vtable generation.
-        if (!isMicrosoftABI()) {
-          MethodVTableIndices[GlobalDecl(DD, Dtor_Complete)]
-              = MI.VTableIndex - AddressPoint;
-          MethodVTableIndices[GlobalDecl(DD, Dtor_Deleting)]
-              = MI.VTableIndex + 1 - AddressPoint;
-        } else {
-          MethodVTableIndices[GlobalDecl(DD, Dtor_Deleting)]
-              = MI.VTableIndex - AddressPoint;
-        }
-      } else {
-        MethodVTableIndices[MD] = MI.VTableIndex - AddressPoint;
-      }
-    }
-  }
-
   // Compute 'this' pointer adjustments.
   ComputeThisAdjustments();
 
   // Add all address points.
+  const CXXRecordDecl *RD = Base.getBase();
   while (true) {
     AddressPoints.insert(std::make_pair(
       BaseSubobject(RD, OffsetInLayoutClass),
@@ -2214,19 +2136,16 @@ void VTableBuilder::dumpLayout(raw_ostream& Out) {
     if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
       // FIXME: Should add a layer of abstraction for vtable generation.
       if (!isMicrosoftABI()) {
-        GlobalDecl GD(DD, Dtor_Complete);
-        assert(MethodVTableIndices.count(GD));
-        uint64_t VTableIndex = MethodVTableIndices[GD];
-        IndicesMap[VTableIndex] = MethodName + " [complete]";
-        IndicesMap[VTableIndex + 1] = MethodName + " [deleting]";
+        IndicesMap[VTables.getMethodVTableIndex(GlobalDecl(DD, Dtor_Complete))]
+          = MethodName + " [complete]";
+        IndicesMap[VTables.getMethodVTableIndex(GlobalDecl(DD, Dtor_Deleting))]
+          = MethodName + " [deleting]";
       } else {
-        GlobalDecl GD(DD, Dtor_Deleting);
-        assert(MethodVTableIndices.count(GD));
-        IndicesMap[MethodVTableIndices[GD]] = MethodName + " [scalar deleting]";
+        IndicesMap[VTables.getMethodVTableIndex(GlobalDecl(DD, Dtor_Deleting))]
+          = MethodName + " [scalar deleting]";
       }
     } else {
-      assert(MethodVTableIndices.count(MD));
-      IndicesMap[MethodVTableIndices[MD]] = MethodName;
+      IndicesMap[VTables.getMethodVTableIndex(MD)] = MethodName;
     }
   }
 
@@ -2241,7 +2160,7 @@ void VTableBuilder::dumpLayout(raw_ostream& Out) {
       uint64_t VTableIndex = I->first;
       const std::string &MethodName = I->second;
 
-      Out << llvm::format("%4" PRIu64 " | ", VTableIndex) << MethodName
+      Out << llvm::format(" %4" PRIu64 " | ", VTableIndex) << MethodName
           << '\n';
     }
   }
@@ -2280,6 +2199,153 @@ VTableContext::~VTableContext() {
   llvm::DeleteContainerSeconds(VTableLayouts);
 }
 
+static void 
+CollectPrimaryBases(const CXXRecordDecl *RD, ASTContext &Context,
+                    VTableBuilder::PrimaryBasesSetVectorTy &PrimaryBases) {
+  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+  const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase();
+
+  if (!PrimaryBase)
+    return;
+
+  CollectPrimaryBases(PrimaryBase, Context, PrimaryBases);
+
+  if (!PrimaryBases.insert(PrimaryBase))
+    llvm_unreachable("Found a duplicate primary base!");
+}
+
+void VTableContext::ComputeMethodVTableIndices(const CXXRecordDecl *RD) {
+  
+  // Itanium C++ ABI 2.5.2:
+  //   The order of the virtual function pointers in a virtual table is the 
+  //   order of declaration of the corresponding member functions in the class.
+  //
+  //   There is an entry for any virtual function declared in a class, 
+  //   whether it is a new function or overrides a base class function, 
+  //   unless it overrides a function from the primary base, and conversion
+  //   between their return types does not require an adjustment. 
+
+  int64_t CurrentIndex = 0;
+  
+  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+  const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase();
+  
+  if (PrimaryBase) {
+    assert(PrimaryBase->isCompleteDefinition() && 
+           "Should have the definition decl of the primary base!");
+
+    // Since the record decl shares its vtable pointer with the primary base
+    // we need to start counting at the end of the primary base's vtable.
+    CurrentIndex = getNumVirtualFunctionPointers(PrimaryBase);
+  }
+
+  // Collect all the primary bases, so we can check whether methods override
+  // a method from the base.
+  VTableBuilder::PrimaryBasesSetVectorTy PrimaryBases;
+  CollectPrimaryBases(RD, Context, PrimaryBases);
+
+  const CXXDestructorDecl *ImplicitVirtualDtor = 0;
+  
+  for (CXXRecordDecl::method_iterator i = RD->method_begin(),
+       e = RD->method_end(); i != e; ++i) {
+    const CXXMethodDecl *MD = *i;
+
+    // We only want virtual methods.
+    if (!MD->isVirtual())
+      continue;
+
+    // Check if this method overrides a method in the primary base.
+    if (const CXXMethodDecl *OverriddenMD = 
+          FindNearestOverriddenMethod(MD, PrimaryBases)) {
+      // Check if converting from the return type of the method to the 
+      // return type of the overridden method requires conversion.
+      if (ComputeReturnAdjustmentBaseOffset(Context, MD, 
+                                            OverriddenMD).isEmpty()) {
+        // This index is shared between the index in the vtable of the primary
+        // base class.
+        if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
+          const CXXDestructorDecl *OverriddenDD = 
+            cast<CXXDestructorDecl>(OverriddenMD);
+
+          if (!isMicrosoftABI()) {
+            // Add both the complete and deleting entries.
+            MethodVTableIndices[GlobalDecl(DD, Dtor_Complete)] =
+              getMethodVTableIndex(GlobalDecl(OverriddenDD, Dtor_Complete));
+            MethodVTableIndices[GlobalDecl(DD, Dtor_Deleting)] =
+              getMethodVTableIndex(GlobalDecl(OverriddenDD, Dtor_Deleting));
+          } else {
+            // Add the scalar deleting destructor.
+            MethodVTableIndices[GlobalDecl(DD, Dtor_Deleting)] =
+              getMethodVTableIndex(GlobalDecl(OverriddenDD, Dtor_Deleting));
+          }
+        } else {
+          MethodVTableIndices[MD] = getMethodVTableIndex(OverriddenMD);
+        }
+        
+        // We don't need to add an entry for this method.
+        continue;
+      }
+    }
+    
+    if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
+      if (MD->isImplicit()) {
+        assert(!ImplicitVirtualDtor && 
+               "Did already see an implicit virtual dtor!");
+        ImplicitVirtualDtor = DD;
+        continue;
+      } 
+
+      if (!isMicrosoftABI()) {
+        // Add the complete dtor.
+        MethodVTableIndices[GlobalDecl(DD, Dtor_Complete)] = CurrentIndex++;
+
+        // Add the deleting dtor.
+        MethodVTableIndices[GlobalDecl(DD, Dtor_Deleting)] = CurrentIndex++;
+      } else {
+        // Add the scalar deleting dtor.
+        MethodVTableIndices[GlobalDecl(DD, Dtor_Deleting)] = CurrentIndex++;
+      }
+    } else {
+      // Add the entry.
+      MethodVTableIndices[MD] = CurrentIndex++;
+    }
+  }
+
+  if (ImplicitVirtualDtor) {
+    // Itanium C++ ABI 2.5.2:
+    //   If a class has an implicitly-defined virtual destructor, 
+    //   its entries come after the declared virtual function pointers.
+
+    if (isMicrosoftABI()) {
+      ErrorUnsupported("implicit virtual destructor in the Microsoft ABI",
+                       ImplicitVirtualDtor->getLocation());
+    }
+
+    // Add the complete dtor.
+    MethodVTableIndices[GlobalDecl(ImplicitVirtualDtor, Dtor_Complete)] = 
+      CurrentIndex++;
+    
+    // Add the deleting dtor.
+    MethodVTableIndices[GlobalDecl(ImplicitVirtualDtor, Dtor_Deleting)] = 
+      CurrentIndex++;
+  }
+  
+  NumVirtualFunctionPointers[RD] = CurrentIndex;
+}
+
+uint64_t VTableContext::getNumVirtualFunctionPointers(const CXXRecordDecl *RD) {
+  llvm::DenseMap<const CXXRecordDecl *, uint64_t>::iterator I = 
+    NumVirtualFunctionPointers.find(RD);
+  if (I != NumVirtualFunctionPointers.end())
+    return I->second;
+
+  ComputeMethodVTableIndices(RD);
+
+  I = NumVirtualFunctionPointers.find(RD);
+  assert(I != NumVirtualFunctionPointers.end() && "Did not find entry!");
+  return I->second;
+}
+      
 uint64_t VTableContext::getMethodVTableIndex(GlobalDecl GD) {
   MethodVTableIndicesTy::iterator I = MethodVTableIndices.find(GD);
   if (I != MethodVTableIndices.end())
@@ -2287,7 +2353,7 @@ uint64_t VTableContext::getMethodVTableIndex(GlobalDecl GD) {
   
   const CXXRecordDecl *RD = cast<CXXMethodDecl>(GD.getDecl())->getParent();
 
-  ComputeVTableRelatedInformation(RD);
+  ComputeMethodVTableIndices(RD);
 
   I = MethodVTableIndices.find(GD);
   assert(I != MethodVTableIndices.end() && "Did not find index!");
@@ -2349,9 +2415,6 @@ void VTableContext::ComputeVTableRelatedInformation(const CXXRecordDecl *RD) {
                         /*MostDerivedClassIsVirtual=*/0, RD);
   Entry = CreateVTableLayout(Builder);
 
-  MethodVTableIndices.insert(Builder.vtable_indices_begin(),
-                             Builder.vtable_indices_end());
-
   // Add the known thunks.
   Thunks.insert(Builder.thunks_begin(), Builder.thunks_end());