[UCRT] Import Microsoft.Windows.SDK.CRTSource version 10.0.22621.3

Imported from https://www.nuget.org/packages/Microsoft.Windows.SDK.CRTSource/10.0.22621.3
License: MIT

sdk/lib/ucrt/heap/recalloc.cpp

@@ -0,0 +1,70 @@
+//
+// recalloc.cpp
+//
+//      Copyright (c) Microsoft Corporation. All rights reserved.
+//
+// Implementation of _recalloc()
+//
+#include <corecrt_internal.h>
+#include <malloc.h>
+#include <string.h>
+
+
+
+// This function provides the logic for the _recalloc() function.  It is called
+// only in the Release CRT (in the Debug CRT, the debug heap has its own
+// implementation of _recalloc()).
+//
+// This function must be marked noinline, otherwise recalloc and
+// _recalloc_base will have identical COMDATs, and the linker will fold
+// them when calling one from the CRT. This is necessary because recalloc
+// needs to support users patching in custom implementations.
+extern "C" __declspec(noinline) void* __cdecl _recalloc_base(
+    void*  const block,
+    size_t const count,
+    size_t const size
+    )
+{
+    // Ensure that (count * size) does not overflow
+    _VALIDATE_RETURN_NOEXC(count == 0 || (_HEAP_MAXREQ / count) >= size, ENOMEM, nullptr);
+
+    size_t const old_block_size = block != nullptr ? _msize_base(block) : 0;
+    size_t const new_block_size = count * size;
+
+    void* const new_block = _realloc_base(block, new_block_size);
+
+    // If the reallocation succeeded and the new block is larger, zero-fill the
+    // new bytes:
+    if (new_block != nullptr && old_block_size < new_block_size)
+    {
+        memset(static_cast<char*>(new_block) + old_block_size, 0, new_block_size - old_block_size);
+    }
+
+    return new_block;
+}
+
+// Reallocates a block of memory in the heap.
+//
+// This function reallocates the block pointed to by 'block' such that it is
+// 'count * size' bytes in size.  The new size may be either greater or less
+// than the original size of the block.  If the new size is greater than the
+// original size, the new bytes are zero-filled.  This function shares its
+// implementation with the realloc() function; consult the comments of that
+// function for more information about the implementation.
+//
+// This function supports patching and therefore must be marked noinline.
+// Both _recalloc_dbg and _recalloc_base must also be marked noinline
+// to prevent identical COMDAT folding from substituting calls to _recalloc
+// with either other function or vice versa.
+extern "C" __declspec(noinline) _CRTRESTRICT void* __cdecl _recalloc(
+    void*  const block,
+    size_t const count,
+    size_t const size
+    )
+{
+    #ifdef _DEBUG
+    return _recalloc_dbg(block, count, size, _NORMAL_BLOCK, nullptr, 0);
+    #else
+    return _recalloc_base(block, count, size);
+    #endif
+}