1 files changed, 323 insertions, 0 deletions

diff --git a/src/dutil/memutil.cpp b/src/dutil/memutil.cpp
new file mode 100644
index 00000000..578c65ee
--- /dev/null
+++ b/src/dutil/memutil.cpp
@@ -0,0 +1,323 @@
+#pragma once
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+
+#include "precomp.h"
+
+
+#if DEBUG
+static BOOL vfMemInitialized = FALSE;
+#endif
+
+extern "C" HRESULT DAPI MemInitialize()
+{
+#if DEBUG
+    vfMemInitialized = TRUE;
+#endif
+    return S_OK;
+}
+
+extern "C" void DAPI MemUninitialize()
+{
+#if DEBUG
+    vfMemInitialized = FALSE;
+#endif
+}
+
+extern "C" LPVOID DAPI MemAlloc(
+    __in SIZE_T cbSize,
+    __in BOOL fZero
+    )
+{
+//    AssertSz(vfMemInitialized, "MemInitialize() not called, this would normally crash");
+    AssertSz(0 < cbSize, "MemAlloc() called with invalid size");
+    return ::HeapAlloc(::GetProcessHeap(), fZero ? HEAP_ZERO_MEMORY : 0, cbSize);
+}
+
+
+extern "C" LPVOID DAPI MemReAlloc(
+    __in LPVOID pv,
+    __in SIZE_T cbSize,
+    __in BOOL fZero
+    )
+{
+//    AssertSz(vfMemInitialized, "MemInitialize() not called, this would normally crash");
+    AssertSz(0 < cbSize, "MemReAlloc() called with invalid size");
+    return ::HeapReAlloc(::GetProcessHeap(), fZero ? HEAP_ZERO_MEMORY : 0, pv, cbSize);
+}
+
+
+extern "C" HRESULT DAPI MemReAllocSecure(
+    __in LPVOID pv,
+    __in SIZE_T cbSize,
+    __in BOOL fZero,
+    __out LPVOID* ppvNew
+    )
+{
+//    AssertSz(vfMemInitialized, "MemInitialize() not called, this would normally crash");
+    AssertSz(ppvNew, "MemReAllocSecure() called with uninitialized pointer");
+    AssertSz(0 < cbSize, "MemReAllocSecure() called with invalid size");
+
+    HRESULT hr = S_OK;
+    DWORD dwFlags = HEAP_REALLOC_IN_PLACE_ONLY;
+    LPVOID pvNew = NULL;
+
+    dwFlags |= fZero ? HEAP_ZERO_MEMORY : 0;
+    pvNew = ::HeapReAlloc(::GetProcessHeap(), dwFlags, pv, cbSize);
+    if (!pvNew)
+    {
+        pvNew = MemAlloc(cbSize, fZero);
+        if (pvNew)
+        {
+            const SIZE_T cbCurrent = MemSize(pv);
+            if (-1 == cbCurrent)
+            {
+                ExitOnFailure(hr = E_INVALIDARG, "Failed to get memory size");
+            }
+
+            // HeapReAlloc may allocate more memory than requested.
+            const SIZE_T cbNew = MemSize(pvNew);
+            if (-1 == cbNew)
+            {
+                ExitOnFailure(hr = E_INVALIDARG, "Failed to get memory size");
+            }
+
+            cbSize = cbNew;
+            if (cbSize > cbCurrent)
+            {
+                cbSize = cbCurrent;
+            }
+
+            memcpy_s(pvNew, cbNew, pv, cbSize);
+
+            SecureZeroMemory(pv, cbCurrent);
+            MemFree(pv);
+        }
+    }
+    ExitOnNull(pvNew, hr, E_OUTOFMEMORY, "Failed to reallocate memory");
+
+    *ppvNew = pvNew;
+    pvNew = NULL;
+
+LExit:
+    ReleaseMem(pvNew);
+
+    return hr;
+}
+
+
+extern "C" HRESULT DAPI MemAllocArray(
+    __inout LPVOID* ppvArray,
+    __in SIZE_T cbArrayType,
+    __in DWORD dwItemCount
+    )
+{
+    return MemReAllocArray(ppvArray, 0, cbArrayType, dwItemCount);
+}
+
+
+extern "C" HRESULT DAPI MemReAllocArray(
+    __inout LPVOID* ppvArray,
+    __in DWORD cArray,
+    __in SIZE_T cbArrayType,
+    __in DWORD dwNewItemCount
+    )
+{
+    HRESULT hr = S_OK;
+    DWORD cNew = 0;
+    LPVOID pvNew = NULL;
+    SIZE_T cbNew = 0;
+
+    hr = ::DWordAdd(cArray, dwNewItemCount, &cNew);
+    ExitOnFailure(hr, "Integer overflow when calculating new element count.");
+
+    hr = ::SIZETMult(cNew, cbArrayType, &cbNew);
+    ExitOnFailure(hr, "Integer overflow when calculating new block size.");
+
+    if (*ppvArray)
+    {
+        SIZE_T cbCurrent = MemSize(*ppvArray);
+        if (cbCurrent < cbNew)
+        {
+            pvNew = MemReAlloc(*ppvArray, cbNew, TRUE);
+            ExitOnNull(pvNew, hr, E_OUTOFMEMORY, "Failed to allocate larger array.");
+
+            *ppvArray = pvNew;
+        }
+    }
+    else
+    {
+        pvNew = MemAlloc(cbNew, TRUE);
+        ExitOnNull(pvNew, hr, E_OUTOFMEMORY, "Failed to allocate new array.");
+
+        *ppvArray = pvNew;
+    }
+
+LExit:
+    return hr;
+}
+
+
+extern "C" HRESULT DAPI MemEnsureArraySize(
+    __deref_out_bcount(cArray * cbArrayType) LPVOID* ppvArray,
+    __in DWORD cArray,
+    __in SIZE_T cbArrayType,
+    __in DWORD dwGrowthCount
+    )
+{
+    HRESULT hr = S_OK;
+    DWORD cNew = 0;
+    LPVOID pvNew = NULL;
+    SIZE_T cbNew = 0;
+
+    hr = ::DWordAdd(cArray, dwGrowthCount, &cNew);
+    ExitOnFailure(hr, "Integer overflow when calculating new element count.");
+
+    hr = ::SIZETMult(cNew, cbArrayType, &cbNew);
+    ExitOnFailure(hr, "Integer overflow when calculating new block size.");
+
+    if (*ppvArray)
+    {
+        SIZE_T cbUsed = cArray * cbArrayType;
+        SIZE_T cbCurrent = MemSize(*ppvArray);
+        if (cbCurrent < cbUsed)
+        {
+            pvNew = MemReAlloc(*ppvArray, cbNew, TRUE);
+            ExitOnNull(pvNew, hr, E_OUTOFMEMORY, "Failed to allocate array larger.");
+
+            *ppvArray = pvNew;
+        }
+    }
+    else
+    {
+        pvNew = MemAlloc(cbNew, TRUE);
+        ExitOnNull(pvNew, hr, E_OUTOFMEMORY, "Failed to allocate new array.");
+
+        *ppvArray = pvNew;
+    }
+
+LExit:
+    return hr;
+}
+
+
+extern "C" HRESULT DAPI MemInsertIntoArray(
+    __deref_out_bcount((cExistingArray + cInsertItems) * cbArrayType) LPVOID* ppvArray,
+    __in DWORD dwInsertIndex,
+    __in DWORD cInsertItems,
+    __in DWORD cExistingArray,
+    __in SIZE_T cbArrayType,
+    __in DWORD dwGrowthCount
+    )
+{
+    HRESULT hr = S_OK;
+    DWORD i;
+    BYTE *pbArray = NULL;
+
+    if (0 == cInsertItems)
+    {
+        ExitFunction1(hr = S_OK);
+    }
+
+    hr = MemEnsureArraySize(ppvArray, cExistingArray + cInsertItems, cbArrayType, dwGrowthCount);
+    ExitOnFailure(hr, "Failed to resize array while inserting items");
+
+    pbArray = reinterpret_cast<BYTE *>(*ppvArray);
+    for (i = cExistingArray + cInsertItems - 1; i > dwInsertIndex; --i)
+    {
+        memcpy_s(pbArray + i * cbArrayType, cbArrayType, pbArray + (i - 1) * cbArrayType, cbArrayType);
+    }
+
+    // Zero out the newly-inserted items
+    memset(pbArray + dwInsertIndex * cbArrayType, 0, cInsertItems * cbArrayType);
+
+LExit:
+    return hr;
+}
+
+extern "C" void DAPI MemRemoveFromArray(
+    __inout_bcount((cExistingArray + cInsertItems) * cbArrayType) LPVOID pvArray,
+    __in DWORD dwRemoveIndex,
+    __in DWORD cRemoveItems,
+    __in DWORD cExistingArray,
+    __in SIZE_T cbArrayType,
+    __in BOOL fPreserveOrder
+    )
+{
+    BYTE *pbArray = static_cast<BYTE *>(pvArray);
+    DWORD cItemsLeftAfterRemoveIndex = (cExistingArray - cRemoveItems - dwRemoveIndex);
+
+    if (fPreserveOrder)
+    {
+        memmove(pbArray + dwRemoveIndex * cbArrayType, pbArray + (dwRemoveIndex + cRemoveItems) * cbArrayType, cItemsLeftAfterRemoveIndex * cbArrayType);
+    }
+    else
+    {
+        DWORD cItemsToMove = (cRemoveItems > cItemsLeftAfterRemoveIndex ? cItemsLeftAfterRemoveIndex : cRemoveItems);
+        memmove(pbArray + dwRemoveIndex * cbArrayType, pbArray + (cExistingArray - cItemsToMove) * cbArrayType, cItemsToMove * cbArrayType);
+    }
+
+    ZeroMemory(pbArray + (cExistingArray - cRemoveItems) * cbArrayType, cRemoveItems * cbArrayType);
+}
+
+extern "C" void DAPI MemArraySwapItems(
+    __inout_bcount((cExistingArray) * cbArrayType) LPVOID pvArray,
+    __in DWORD dwIndex1,
+    __in DWORD dwIndex2,
+    __in SIZE_T cbArrayType
+    )
+{
+    BYTE *pbArrayItem1 = static_cast<BYTE *>(pvArray) + dwIndex1 * cbArrayType;
+    BYTE *pbArrayItem2 = static_cast<BYTE *>(pvArray) + dwIndex2 * cbArrayType;
+    DWORD dwByteIndex = 0;
+
+    if (dwIndex1 == dwIndex2)
+    {
+        return;
+    }
+
+    // Use XOR swapping to avoid the need for a temporary item
+    while (dwByteIndex < cbArrayType)
+    {
+        // Try to do many bytes at a time in most cases
+        if (cbArrayType - dwByteIndex > sizeof(DWORD64))
+        {
+            // x: X xor Y
+            *(reinterpret_cast<DWORD64 *>(pbArrayItem1 + dwByteIndex)) ^= *(reinterpret_cast<DWORD64 *>(pbArrayItem2 + dwByteIndex));
+            // y: X xor Y
+            *(reinterpret_cast<DWORD64 *>(pbArrayItem2 + dwByteIndex)) = *(reinterpret_cast<DWORD64 *>(pbArrayItem1 + dwByteIndex)) ^ *(reinterpret_cast<DWORD64 *>(pbArrayItem2 + dwByteIndex));
+            // x: X xor Y
+            *(reinterpret_cast<DWORD64 *>(pbArrayItem1 + dwByteIndex)) ^= *(reinterpret_cast<DWORD64 *>(pbArrayItem2 + dwByteIndex));
+
+            dwByteIndex += sizeof(DWORD64);
+        }
+        else
+        {
+            // x: X xor Y
+            *(reinterpret_cast<unsigned char *>(pbArrayItem1 + dwByteIndex)) ^= *(reinterpret_cast<unsigned char *>(pbArrayItem2 + dwByteIndex));
+            // y: X xor Y
+            *(reinterpret_cast<unsigned char *>(pbArrayItem2 + dwByteIndex)) = *(reinterpret_cast<unsigned char *>(pbArrayItem1 + dwByteIndex)) ^ *(reinterpret_cast<unsigned char *>(pbArrayItem2 + dwByteIndex));
+            // x: X xor Y
+            *(reinterpret_cast<unsigned char *>(pbArrayItem1 + dwByteIndex)) ^= *(reinterpret_cast<unsigned char *>(pbArrayItem2 + dwByteIndex));
+
+            dwByteIndex += sizeof(unsigned char);
+        }
+    }
+}
+
+extern "C" HRESULT DAPI MemFree(
+    __in LPVOID pv
+    )
+{
+//    AssertSz(vfMemInitialized, "MemInitialize() not called, this would normally crash");
+    return ::HeapFree(::GetProcessHeap(), 0, pv) ? S_OK : HRESULT_FROM_WIN32(::GetLastError());
+}
+
+
+extern "C" SIZE_T DAPI MemSize(
+    __in LPCVOID pv
+    )
+{
+//    AssertSz(vfMemInitialized, "MemInitialize() not called, this would normally crash");
+    return ::HeapSize(::GetProcessHeap(), 0, pv);
+}