Delete ArrayEEClass - compute multidim array rank from BaseSize

docs/design/datacontracts/RuntimeTypeSystem.md

@@ -372,6 +372,7 @@ The contract depends on the following globals
 | --- | --- |
 | `FreeObjectMethodTablePointer` | A pointer to the address of a `MethodTable` used by the GC to indicate reclaimed memory
 | `StaticsPointerMask` | For masking out a bit of DynamicStaticsInfo pointer fields
+| `ArrayBaseSize` | The base size of an array object; used to compute multidimensional array rank from `MethodTable::BaseSize`
 
 The contract additionally depends on these data descriptors
 
@@ -403,7 +404,6 @@ The contract additionally depends on these data descriptors
 | `EEClass` | `NumStaticFields` | Count of static fields of the EEClass |
 | `EEClass` | `NumThreadStaticFields` | Count of threadstatic fields of the EEClass |
 | `EEClass` | `FieldDescList` | A list of fields in the type |
-| `ArrayClass` | `Rank` | Rank of the associated array MethodTable |
 | `TypeDesc` | `TypeAndFlags` | The lower 8 bits are the CorElementType of the `TypeDesc`, the upper 24 bits are reserved for flags |
 | `ParamTypeDesc` | `TypeArg` | Associated type argument |
 | `TypeVarTypeDesc` | `Module` | Pointer to module which defines the type variable |
@@ -695,8 +695,9 @@ Contracts used:
             switch (typeHandle.Flags.GetFlag(WFLAGS_HIGH.Category_Mask))
             {
                 case WFLAGS_HIGH.Category_Array:
-                    TargetPointer clsPtr = GetClassPointer(typeHandle);
-                    rank = // Read Rank field from ArrayClass contract using address clsPtr
+                    // Multidim array: BaseSize = ArrayBaseSize + Rank * sizeof(uint) * 2
+                    uint arrayBaseSize = target.ReadGlobal<uint>("ArrayBaseSize");
+                    rank = (typeHandle.Flags.BaseSize - arrayBaseSize) / (sizeof(uint) * 2);
                     return true;
 
                 case WFLAGS_HIGH.Category_Array | WFLAGS_HIGH.Category_IfArrayThenSzArray:

src/coreclr/vm/array.cpp

@@ -66,7 +66,7 @@ DWORD ArrayMethodDesc::GetAttrs()
 // Generate a short sig (descr) for an array accessors
 //
 
-VOID ArrayClass::GenerateArrayAccessorCallSig(
+static void GenerateArrayAccessorCallSig(
     DWORD   dwRank,
     DWORD   dwFuncType,    // Load, store, or <init>
     PCCOR_SIGNATURE *ppSig,// Generated signature
@@ -180,7 +180,7 @@ VOID ArrayClass::GenerateArrayAccessorCallSig(
 //
 // Based on code in class.cpp.
 //
-void ArrayClass::InitArrayMethodDesc(
+static void InitArrayMethodDesc(
     ArrayMethodDesc *pNewMD,
     PCCOR_SIGNATURE pShortSig,
     DWORD   cShortSig,
@@ -200,9 +200,9 @@ void ArrayClass::InitArrayMethodDesc(
     pNewMD->SetTemporaryEntryPoint(pamTracker);
 
 #ifdef _DEBUG
-    _ASSERTE(pNewMD->GetMethodName() && GetDebugClassName());
+    _ASSERTE(pNewMD->GetMethodName() && pNewMD->GetMethodTable()->GetClass()->GetDebugClassName());
     pNewMD->m_pszDebugMethodName = pNewMD->GetMethodName();
-    pNewMD->m_pszDebugClassName  = GetDebugClassName();
+    pNewMD->m_pszDebugClassName  = pNewMD->GetMethodTable()->GetClass()->GetDebugClassName();
     pNewMD->m_pDebugMethodTable = pNewMD->GetMethodTable();
 #endif // _DEBUG
 }
@@ -294,33 +294,32 @@ MethodTable* Module::CreateArrayMethodTable(TypeHandle elemTypeHnd, CorElementTy
     cbMT += pParentClass->GetNumInterfaces() * sizeof(InterfaceInfo_t);
 
 
-    size_t cbArrayClass = 0;
+    size_t cbEEClass = 0;
 
     if (pCanonMT == NULL)
     {
-        // Allocate ArrayClass, MethodTable, and class name in one alloc.
-        // Remember to pad allocation size for ArrayClass portion to ensure MethodTable is pointer aligned.
-        cbArrayClass = ALIGN_UP(sizeof(ArrayClass), sizeof(void*));
+        // Allocate EEClass, MethodTable, and class name in one alloc.
+        // Remember to pad allocation size for EEClass portion to ensure MethodTable is pointer aligned.
+        cbEEClass = ALIGN_UP(sizeof(EEClass), sizeof(void*));
     }
 
-    // ArrayClass already includes one void*
     LoaderAllocator* pAllocator= this->GetLoaderAllocator();
-    BYTE* pMemory = (BYTE *)pamTracker->Track(pAllocator->GetHighFrequencyHeap()->AllocMem(S_SIZE_T(cbArrayClass) +
+    BYTE* pMemory = (BYTE *)pamTracker->Track(pAllocator->GetHighFrequencyHeap()->AllocMem(S_SIZE_T(cbEEClass) +
                                                                                             S_SIZE_T(cbMT)));
 
     // Note: Memory allocated on loader heap is zero filled
-    // memset(pMemory, 0, sizeof(ArrayClass) + cbMT);
+    // memset(pMemory, 0, sizeof(EEClass) + cbMT);
 
-    ArrayClass* pClass = NULL;
+    EEClass* pClass = NULL;
 
     if (pCanonMT == NULL)
     {
-        pClass = ::new (pMemory) ArrayClass();
+        pClass = ::new (pMemory) EEClass();
     }
 
-    // Head of MethodTable memory (starts after ArrayClass), this points at the GCDesc stuff in front
+    // Head of MethodTable memory (starts after EEClass), this points at the GCDesc stuff in front
     // of a method table (if needed)
-    BYTE* pMTHead = pMemory + cbArrayClass + cbCGCDescData;
+    BYTE* pMTHead = pMemory + cbEEClass + cbCGCDescData;
 
     MethodTable* pMT = (MethodTable *) pMTHead;
 
@@ -336,7 +335,6 @@ MethodTable* Module::CreateArrayMethodTable(TypeHandle elemTypeHnd, CorElementTy
     {
         pClass->SetInternalCorElementType(arrayKind);
         pClass->SetAttrClass (tdPublic | tdSerializable | tdSealed);  // This class is public, serializable, sealed
-        pClass->SetRank (Rank);
         pClass->SetMethodTable (pMT);
 
         // Fill In the method table
@@ -505,9 +503,9 @@ MethodTable* Module::CreateArrayMethodTable(TypeHandle elemTypeHnd, CorElementTy
             PCCOR_SIGNATURE pSig;
             DWORD           cSig;
 
-            pClass->GenerateArrayAccessorCallSig(dwFuncRank, dwFuncType, &pSig, &cSig, pAllocator, pamTracker, FALSE);
+            GenerateArrayAccessorCallSig(dwFuncRank, dwFuncType, &pSig, &cSig, pAllocator, pamTracker, FALSE);
 
-            pClass->InitArrayMethodDesc(pNewMD, pSig, cSig, numVirtuals + dwMethodIndex, pamTracker);
+            InitArrayMethodDesc(pNewMD, pSig, cSig, numVirtuals + dwMethodIndex, pamTracker);
 
             dwMethodIndex++;
         }
@@ -882,13 +880,13 @@ Stub *GenerateArrayOpStub(ArrayMethodDesc* pMD)
     {
          // The stub has to have signature with explicit hidden argument instead of CORINFO_CALLCONV_PARAMTYPE.
          // Generate a new signature for the stub here.
-         ((ArrayClass*)(pMD->GetMethodTable()->GetClass()))->GenerateArrayAccessorCallSig(pMD->GetMethodTable()->GetRank(),
-                                                                                          ArrayMethodDesc::ARRAY_FUNC_ADDRESS,
-                                                                                          &pSig,
-                                                                                          &cbSig,
-                                                                                          pMD->GetLoaderAllocator(),
-                                                                                          &amTracker,
-                                                                                          1);
+         GenerateArrayAccessorCallSig(pMD->GetMethodTable()->GetRank(),
+                                      ArrayMethodDesc::ARRAY_FUNC_ADDRESS,
+                                      &pSig,
+                                      &cbSig,
+                                      pMD->GetLoaderAllocator(),
+                                      &amTracker,
+                                      1);
     }
     else
     {

src/coreclr/vm/ceeload.h

@@ -444,7 +444,6 @@ class ModuleBase
 {
 #ifdef DACCESS_COMPILE
     friend class ClrDataAccess;
-    friend class NativeImageDumper;
 #endif
 
     friend class DataImage;
@@ -603,7 +602,6 @@ class Module : public ModuleBase
 {
 #ifdef DACCESS_COMPILE
     friend class ClrDataAccess;
-    friend class NativeImageDumper;
 #endif
 
     friend class DataImage;

src/coreclr/vm/class.h

@@ -61,7 +61,6 @@ VOID DECLSPEC_NORETURN RealCOMPlusThrowHR(HRESULT hr);
  *  Forward declarations
  */
 class   AppDomain;
-class   ArrayClass;
 class   ArrayMethodDesc;
 class   Assembly;
 class   ClassLoader;
@@ -726,6 +725,7 @@ class EEClass // DO NOT CREATE A NEW EEClass USING NEW!
     friend class FieldDesc;
     friend class CheckAsmOffsets;
     friend class ClrDataAccess;
+    friend MethodTable* Module::CreateArrayMethodTable(TypeHandle, CorElementType, unsigned, AllocMemTracker*);
 
     /************************************
      *  PUBLIC INSTANCE METHODS
@@ -1913,64 +1913,6 @@ class DelegateEEClass : public EEClass
 };
 
 
-typedef DPTR(ArrayClass) PTR_ArrayClass;
-
-
-// Dynamically generated array class structure
-class ArrayClass : public EEClass
-{
-    friend MethodTable* Module::CreateArrayMethodTable(TypeHandle elemTypeHnd, CorElementType arrayKind, unsigned Rank, AllocMemTracker *pamTracker);
-
-#ifndef DACCESS_COMPILE
-    ArrayClass() { LIMITED_METHOD_CONTRACT; }
-#else
-    friend class NativeImageDumper;
-#endif
-
-private:
-
-    DAC_ALIGNAS(EEClass) // Align the first member to the alignment of the base class
-    unsigned char   m_rank;
-
-public:
-    DWORD GetRank() {
-        LIMITED_METHOD_CONTRACT;
-        SUPPORTS_DAC;
-        return m_rank;
-    }
-    void SetRank (unsigned Rank) {
-        LIMITED_METHOD_CONTRACT;
-        // The only code path calling this function is code:ClassLoader::CreateTypeHandleForTypeKey, which has
-        // checked the rank already.  Assert that the rank is less than MAX_RANK and that it fits in one byte.
-        _ASSERTE((Rank <= MAX_RANK) && (Rank <= (unsigned char)(-1)));
-        m_rank = (unsigned char)Rank;
-    }
-
-    // Allocate a new MethodDesc for the methods we add to this class
-    void InitArrayMethodDesc(
-        ArrayMethodDesc* pNewMD,
-        PCCOR_SIGNATURE pShortSig,
-        DWORD   cShortSig,
-        DWORD   dwVtableSlot,
-        AllocMemTracker *pamTracker);
-
-    // Generate a short sig for an array accessor
-    VOID GenerateArrayAccessorCallSig(DWORD   dwRank,
-                                      DWORD   dwFuncType, // Load, store, or <init>
-                                      PCCOR_SIGNATURE *ppSig, // Generated signature
-                                      DWORD * pcSig,      // Generated signature size
-                                      LoaderAllocator *pLoaderAllocator,
-                                      AllocMemTracker *pamTracker,
-                                      BOOL fForStubAsIL
-    );
-
-    friend struct ::cdac_data<ArrayClass>;
-};
-
-template<> struct cdac_data<ArrayClass>
-{
-    static constexpr size_t Rank = offsetof(ArrayClass, m_rank);
-};
 
 inline EEClassLayoutInfo *EEClass::GetLayoutInfo()
 {

src/coreclr/vm/classcompat.h

@@ -33,7 +33,6 @@
  *  Forward declarations
  */
 class   AppDomain;
-class   ArrayClass;
 class   ArrayMethodDesc;
 class   Assembly;
 class   ClassLoader;

src/coreclr/vm/datadescriptor/datadescriptor.inc

@@ -343,11 +343,6 @@ CDAC_TYPE_FIELD(EEClass, /*uint16*/, NumThreadStaticFields, cdac_data<EEClass>::
 CDAC_TYPE_FIELD(EEClass, /*uint16*/, NumNonVirtualSlots, cdac_data<EEClass>::NumNonVirtualSlots)
 CDAC_TYPE_END(EEClass)
 
-CDAC_TYPE_BEGIN(ArrayClass)
-CDAC_TYPE_INDETERMINATE(ArrayClass)
-CDAC_TYPE_FIELD(ArrayClass, /*uint8*/, Rank, cdac_data<ArrayClass>::Rank)
-CDAC_TYPE_END(ArrayClass)
-
 CDAC_TYPE_BEGIN(GenericsDictInfo)
 CDAC_TYPE_INDETERMINATE(GenericsDictInfo)
 CDAC_TYPE_FIELD(GenericsDictInfo, /*uint16*/, NumDicts, offsetof(GenericsDictInfo, m_wNumDicts))
@@ -1162,6 +1157,7 @@ CDAC_GLOBAL(HashMapSlotsPerBucket, uint32, SLOTS_PER_BUCKET)
 CDAC_GLOBAL(HashMapValueMask, uint64, VALUE_MASK)
 CDAC_GLOBAL(MethodDescAlignment, uint64, MethodDesc::ALIGNMENT)
 CDAC_GLOBAL(ObjectHeaderSize, uint64, OBJHEADER_SIZE)
+CDAC_GLOBAL(ArrayBaseSize, uint32, ARRAYBASE_BASESIZE)
 CDAC_GLOBAL(SyncBlockValueToObjectOffset, uint16, OBJHEADER_SIZE - cdac_data<ObjHeader>::SyncBlockValue)
 CDAC_GLOBAL(StubCodeBlockLast, uint8, STUB_CODE_BLOCK_LAST)
 CDAC_GLOBAL(DefaultADID, uint32, DefaultADID)

src/coreclr/vm/methodtable.cpp

@@ -1460,8 +1460,7 @@ BOOL MethodTable::ArrayIsInstanceOf(MethodTable* pTargetMT, TypeHandlePairList*
         PRECONDITION(pTargetMT->IsArray());
     } CONTRACTL_END;
 
-    // GetRank touches EEClass. Try to avoid it for SZArrays.
-    if (pTargetMT->GetInternalCorElementType() == ELEMENT_TYPE_SZARRAY)
+    if (!pTargetMT->IsMultiDimArray())
     {
         if (this->IsMultiDimArray())
         {
@@ -7790,15 +7789,6 @@ MethodTable::EnumMemoryRegions(CLRDataEnumMemoryFlags flags)
 
         if (pClass.IsValid())
         {
-            if (IsArray())
-            {
-                // This is kind of a workaround, in that ArrayClass is derived from EEClass, but
-                // it's not virtual, we only cast if the IsArray() predicate holds above.
-                // For minidumps, DAC will choke if we don't have the full size given
-                // by ArrayClass available. If ArrayClass becomes more complex, it
-                // should get it's own EnumMemoryRegions().
-                DacEnumMemoryRegion(dac_cast<TADDR>(pClass), sizeof(ArrayClass));
-            }
             pClass->EnumMemoryRegions(flags, this);
         }
         else

src/coreclr/vm/methodtable.h

@@ -32,7 +32,6 @@
  * Forward Declarations
  */
 class    AppDomain;
-class    ArrayClass;
 class    ArrayMethodDesc;
 class ClassLoader;
 class FCallMethodDesc;
@@ -316,9 +315,6 @@ typedef DPTR(GenericsStaticsInfo) PTR_GenericsStaticsInfo;
 struct MethodTableAuxiliaryData
 {
     friend class MethodTable;
-#if defined(DACCESS_COMPILE)
-    friend class NativeImageDumper;
-#endif
 
     enum
     {
@@ -970,9 +966,6 @@ class MethodTable
     friend class EEClass;
     friend class MethodTableBuilder;
     friend class CheckAsmOffsets;
-#if defined(DACCESS_COMPILE)
-    friend class NativeImageDumper;
-#endif
 
 public:
     // Do some sanity checking to make sure it's a method table

src/coreclr/vm/methodtable.inl

@@ -316,7 +316,11 @@ inline DWORD MethodTable::GetRank()
     if (GetFlag(enum_flag_Category_IfArrayThenSzArray))
         return 1;  // ELEMENT_TYPE_SZARRAY
     else
-        return dac_cast<PTR_ArrayClass>(GetClass())->GetRank();
+    {
+        // Multidim array: BaseSize = ARRAYBASE_BASESIZE + Rank * sizeof(DWORD) * 2
+        DWORD boundsSize = GetBaseSize() - ARRAYBASE_BASESIZE;
+        return boundsSize / (sizeof(DWORD) * 2);
+    }
 }
 
 //==========================================================================================

src/coreclr/vm/object.inl

@@ -179,7 +179,7 @@ inline /* static */ unsigned ArrayBase::GetLowerBoundsOffset(MethodTable* pMT)
     // Lower bounds info is after total bounds info
     // and total bounds info has rank elements
     return GetBoundsOffset(pMT) +
-        dac_cast<PTR_ArrayClass>(pMT->GetClass())->GetRank() *
+        pMT->GetRank() *
         sizeof(INT32);
 }
 

src/coreclr/vm/vars.hpp

@@ -33,7 +33,6 @@ class LoaderHeap;
 class IGCHeap;
 class Object;
 class StringObject;
-class ArrayClass;
 class MethodTable;
 class MethodDesc;
 class SyncBlockCache;

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/DataType.cs

@@ -51,7 +51,6 @@ public enum DataType
     DynamicStaticsInfo,
     EEClass,
     CoreLibBinder,
-    ArrayClass,
     MethodTableAuxiliaryData,
     GenericsDictInfo,
     TypeDesc,

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Constants.cs

@@ -53,6 +53,7 @@ public static class Globals
 
         public const string MethodDescAlignment = nameof(MethodDescAlignment);
         public const string ObjectHeaderSize = nameof(ObjectHeaderSize);
+        public const string ArrayBaseSize = nameof(ArrayBaseSize);
         public const string SyncBlockValueToObjectOffset = nameof(SyncBlockValueToObjectOffset);
 
         public const string SyncTableEntries = nameof(SyncTableEntries);

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/RuntimeTypeSystem_1.cs

@@ -731,8 +731,10 @@ public bool IsArray(TypeHandle typeHandle, out uint rank)
             switch (methodTable.Flags.GetFlag(MethodTableFlags_1.WFLAGS_HIGH.Category_Mask))
             {
                 case MethodTableFlags_1.WFLAGS_HIGH.Category_Array:
-                    TargetPointer clsPtr = GetClassPointer(typeHandle);
-                    rank = _target.ProcessedData.GetOrAdd<Data.ArrayClass>(clsPtr).Rank;
+                    // Multidim array: BaseSize = ArrayBaseSize + Rank * sizeof(uint) * 2
+                    uint arrayBaseSize = _target.ReadGlobal<uint>(Constants.Globals.ArrayBaseSize);
+                    uint boundsSize = methodTable.Flags.BaseSize - arrayBaseSize;
+                    rank = boundsSize / (sizeof(uint) * 2);
                     return true;
 
                 case MethodTableFlags_1.WFLAGS_HIGH.Category_Array | MethodTableFlags_1.WFLAGS_HIGH.Category_IfArrayThenSzArray:

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Data/EEClass.cs

@@ -41,16 +41,3 @@ public EEClass(Target target, TargetPointer address)
     public TargetPointer FieldDescList { get; init; }
     public ushort NumNonVirtualSlots { get; init; }
 }
-
-internal sealed class ArrayClass : IData<ArrayClass>
-{
-    static ArrayClass IData<ArrayClass>.Create(Target target, TargetPointer address) => new ArrayClass(target, address);
-    public ArrayClass(Target target, TargetPointer address)
-    {
-        Target.TypeInfo type = target.GetTypeInfo(DataType.ArrayClass);
-
-        Rank = target.Read<byte>(address + (ulong)type.Fields[nameof(Rank)].Offset);
-    }
-
-    public byte Rank { get; init; }
-}