Fix ClassMetadataBuilderBase::FieldLayout ASAN violations

There’s something Off™ about the ClassMetadataBuilderBase<Derived>::FieldLayout reference inherited by SpecializedGenericClassMetadataBuilder; work around it by using an accessor that accesses a derived-class equivalent. Fixes widespread test failures in unoptimized swift-frontends.

Author: beccadax

lib/IRGen/GenMeta.cpp

@@ -3440,6 +3440,8 @@ namespace {
         MetadataLayout(IGM.getClassMetadataLayout(theClass)) {}
 
   public:
+    const ClassLayout &getFieldLayout() const { return FieldLayout; }
+
     SILType getLoweredType() {
       return IGM.getLoweredType(Target->getDeclaredTypeInContext());
     }
@@ -3452,7 +3454,7 @@ namespace {
     ClassFlags getClassFlags() { return ::getClassFlags(Target); }
 
     void addClassFlags() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       B.addInt32((uint32_t)asImpl().getClassFlags());
@@ -3490,7 +3492,7 @@ namespace {
     }
 
     void addValueWitnessTable() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       B.add(asImpl().getValueWitnessTable(false).getValue());
@@ -3583,7 +3585,7 @@ namespace {
     }
 
     void addDestructorFunction() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       if (auto ptr = getAddrOfDestructorFunction(IGM, Target)) {
@@ -3598,7 +3600,7 @@ namespace {
     }
 
     void addIVarDestroyer() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       auto dtorFunc = IGM.getAddrOfIVarInitDestroy(Target,
@@ -3623,7 +3625,7 @@ namespace {
     }
 
     void addNominalTypeDescriptor() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       B.addSignedPointer(asImpl().getNominalTypeDescriptor(),
@@ -3640,7 +3642,7 @@ namespace {
     }
 
     void addInstanceAddressPoint() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       // Right now, we never allocate fields before the address point.
@@ -3652,7 +3654,7 @@ namespace {
     const ClassLayout &getFieldLayout() { return FieldLayout; }
 
     void addInstanceSize() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       if (asImpl().hasFixedLayout()) {
@@ -3664,7 +3666,7 @@ namespace {
     }
 
     void addInstanceAlignMask() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       if (asImpl().hasFixedLayout()) {
@@ -3676,22 +3678,22 @@ namespace {
     }
 
     void addRuntimeReservedBits() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       B.addInt16(0);
     }
 
     void addClassSize() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       auto size = MetadataLayout.getSize();
       B.addInt32(size.FullSize.getValue());
     }
 
     void addClassAddressPoint() {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       // FIXME: Wrong
@@ -3725,7 +3727,7 @@ namespace {
       // Derive the RO-data.
       llvm::Constant *data = asImpl().getROData();
 
-      if (!FieldLayout.hasObjCImplementation()) {
+      if (!asImpl().getFieldLayout().hasObjCImplementation()) {
         // Set a low bit to indicate this class has Swift metadata.
         auto bit = llvm::ConstantInt::get(
             IGM.IntPtrTy, asImpl().getClassDataPointerHasSwiftMetadataBits());
@@ -3833,7 +3835,7 @@ namespace {
       : super(IGM, theClass, builder, fieldLayout) {}
 
     void addFieldOffset(VarDecl *var) {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       addFixedFieldOffset(IGM, B, var, [](DeclContext *dc) {
@@ -3872,7 +3874,7 @@ namespace {
       : super(IGM, theClass, builder, fieldLayout) {}
 
     void addFieldOffset(VarDecl *var) {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       // Field offsets are either copied from the superclass or calculated
@@ -3881,7 +3883,7 @@ namespace {
     }
 
     void addFieldOffsetPlaceholders(MissingMemberDecl *placeholder) {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       for (unsigned i = 0,
@@ -4343,7 +4345,7 @@ namespace {
     }
 
     void addFieldOffset(VarDecl *var) {
-      if (FieldLayout.hasObjCImplementation())
+      if (asImpl().getFieldLayout().hasObjCImplementation())
         return;
 
       addFixedFieldOffset(IGM, B, var, [&](DeclContext *dc) {

test/IRGen/prespecialized-metadata/class-fileprivate-inmodule-1argument-2ancestor-1du-1st_ancestor_generic-fileprivate-2nd_ancestor_nongeneric.swift

@@ -1,6 +1,7 @@
 // RUN: %empty-directory(%t)
 
-// RUN: %target-swift-frontend -prespecialize-generic-metadata -target %module-target-future -emit-ir -I %t -L %t %s | %FileCheck %s -DINT=i%target-ptrsize -DALIGNMENT=%target-alignment --check-prefix=CHECK --check-prefix=CHECK-%target-vendor
+// RUN: %target-swift-frontend -prespecialize-generic-metadata -target %module-target-future -emit-ir -I %t -L %t %s > %t/out.ir
+// RUN: %FileCheck --input-file=%t/out.ir %s -DINT=i%target-ptrsize -DALIGNMENT=%target-alignment --check-prefix=CHECK --check-prefix=CHECK-%target-vendor
 
 // REQUIRES: VENDOR=apple || OS=linux-gnu
 // UNSUPPORTED: CPU=i386 && OS=ios