Allocator shims working on VS2015.

base/allocator/allocator_shim_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// The allocator shim is only enabled in Release Static builds.
+// This #if is needed as gyp can't have different compile
+// targets between Debug and Release.
+// TODO(wfh): Remove this once gyp is dead.
+#if defined(ALLOCATOR_SHIM)
+
 #include <limits.h>
 #include <malloc.h>
 #include <new.h>
 #include <windows.h>
 #include <stddef.h>
 
+#include "allocator_shim_win.h"
+
 // This shim make it possible to perform additional checks on allocations
 // before passing them to the Heap functions.
 
-// Heap functions are stripped from libcmt.lib using the prep_libc.py
-// for each object file stripped, we re-implement them here to allow us to
-// perform additional checks:
+// Override heap functions to perform additional checks:
 // 1. Enforcing the maximum size that can be allocated to 2Gb.
-// 2. Calling new_handler if malloc fails.
+// 2. Calling new_handler if malloc fails
 
-extern "C" {
-// We set this to 1 because part of the CRT uses a check of _crtheap != 0
-// to test whether the CRT has been initialized.  Once we've ripped out
-// the allocators from libcmt, we need to provide this definition so that
-// the rest of the CRT is still usable.
-// heapinit.c
-void* _crtheap = reinterpret_cast<void*>(1);
-}
+// See definitions of original functions in ucrt\corecrt_malloc.h in SDK
+// include directory.
 
 namespace base {
 namespace allocator {
 bool g_is_win_shim_layer_initialized = false;
 }  // namespace allocator
 }  // namespace base
 
 namespace {
 
 const size_t kWindowsPageSize = 4096;
 const size_t kMaxWindowsAllocation = INT_MAX - kWindowsPageSize;
 int new_mode = 0;
 
-// VS2013 crt uses the process heap as its heap, so we do the same here.
-// See heapinit.c in VS CRT sources.
-bool win_heap_init() {
-  // Set the _crtheap global here.  THis allows us to offload most of the
-  // memory management to the CRT, except the functions we need to shim.
-  _crtheap = GetProcessHeap();
-  return _crtheap != nullptr;
+inline HANDLE get_heap_handle() {
+  return reinterpret_cast<HANDLE>(_get_heap_handle());
 }
 
 void* win_heap_malloc(size_t size) {
   if (size < kMaxWindowsAllocation)
-    return HeapAlloc(_crtheap, 0, size);
-  return NULL;
+    return HeapAlloc(get_heap_handle(), 0, size);
+  return nullptr;
 }
 
 void win_heap_free(void* size) {
-  HeapFree(_crtheap, 0, size);
+  HeapFree(get_heap_handle(), 0, size);
 }
 
 void* win_heap_realloc(void* ptr, size_t size) {
   if (!ptr)
     return win_heap_malloc(size);
   if (!size) {
     win_heap_free(ptr);
-    return NULL;
+    return nullptr;
   }
   if (size < kMaxWindowsAllocation)
-    return HeapReAlloc(_crtheap, 0, ptr, size);
-  return NULL;
-}
-
-void win_heap_term() {
-  _crtheap = NULL;
+    return HeapReAlloc(get_heap_handle(), 0, ptr, size);
+  return nullptr;
 }
 
 // Call the new handler, if one has been set.
 // Returns true on successfully calling the handler, false otherwise.
 inline bool call_new_handler(bool nothrow, size_t size) {
   // Get the current new handler.
   _PNH nh = _query_new_handler();
 #if defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS
   if (!nh)
     return false;
   // Since exceptions are disabled, we don't really know if new_handler
   // failed.  Assume it will abort if it fails.
-  return nh(size);
+  return nh(size) ? true : false;
 #else
 #error "Exceptions in allocator shim are not supported!"
 #endif  // defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS
-  return false;
-}
-
-// Implement a C++ style allocation, which always calls the new_handler
-// on failure.
-inline void* generic_cpp_alloc(size_t size, bool nothrow) {
-  void* ptr;
-  for (;;) {
-    ptr = malloc(size);
-    if (ptr)
-      return ptr;
-    if (!call_new_handler(nothrow, size))
-      break;
-  }
-  return ptr;
 }
 
 }  // namespace
 
-// new.cpp
-void* operator new(size_t size) {
-  return generic_cpp_alloc(size, false);
-}
+extern "C" {
 
-// delete.cpp
-void operator delete(void* p) throw() {
-  free(p);
-}
-
-// new2.cpp
-void* operator new[](size_t size) {
-  return generic_cpp_alloc(size, false);
-}
-
-// delete2.cpp
-void operator delete[](void* p) throw() {
-  free(p);
-}
-
-// newopnt.cpp
-void* operator new(size_t size, const std::nothrow_t& nt) {
-  return generic_cpp_alloc(size, true);
-}
-
-// newaopnt.cpp
-void* operator new[](size_t size, const std::nothrow_t& nt) {
-  return generic_cpp_alloc(size, true);
-}
+// Symbol to allow weak linkage to win_heap_malloc from memory_win.cc.
+void* (*malloc_unchecked)(size_t) = &win_heap_malloc;
 
 // This function behaves similarly to MSVC's _set_new_mode.
 // If flag is 0 (default), calls to malloc will behave normally.
 // If flag is 1, calls to malloc will behave like calls to new,
 // and the std_new_handler will be invoked on failure.
 // Returns the previous mode.
-// new_mode.cpp
-int _set_new_mode(int flag) throw() {
+//
+// Replaces _set_new_mode in ucrt\heap\new_mode.cpp
+int _set_new_mode(int flag) {
+  // The MS CRT calls this function early on in startup, so this serves as a low
+  // overhead proof that the allocator shim is in place for this process.
+  base::allocator::g_is_win_shim_layer_initialized = true;
   int old_mode = new_mode;
   new_mode = flag;
   return old_mode;
 }
 
-// new_mode.cpp
+// Replaces _query_new_mode in ucrt\heap\new_mode.cpp
 int _query_new_mode() {
   return new_mode;
 }
 
-extern "C" {
-// malloc.c
-void* malloc(size_t size) {
+// Replaces malloc in ucrt\heap\malloc.cpp
+__declspec(restrict) void* malloc(size_t size) {
   void* ptr;
   for (;;) {
     ptr = win_heap_malloc(size);
     if (ptr)
       return ptr;
 
     if (!new_mode || !call_new_handler(true, size))
       break;
   }
   return ptr;
 }
 
-// Symbol to allow weak linkage to win_heap_malloc from memory_win.cc.
-void* (*malloc_unchecked)(size_t) = &win_heap_malloc;
-
-// free.c
+// Replaces free in ucrt\heap\free.cpp
 void free(void* p) {
   win_heap_free(p);
   return;
 }
 
-// realloc.c
-void* realloc(void* ptr, size_t size) {
+// Replaces realloc in ucrt\heap\realloc.cpp
+__declspec(restrict) void* realloc(void* ptr, size_t size) {
   // Webkit is brittle for allocators that return NULL for malloc(0).  The
   // realloc(0, 0) code path does not guarantee a non-NULL return, so be sure
   // to call malloc for this case.
   if (!ptr)
     return malloc(size);
 
   void* new_ptr;
   for (;;) {
     new_ptr = win_heap_realloc(ptr, size);
 
     // Subtle warning:  NULL return does not alwas indicate out-of-memory.  If
     // the requested new size is zero, realloc should free the ptr and return
     // NULL.
     if (new_ptr || !size)
       return new_ptr;
     if (!new_mode || !call_new_handler(true, size))
       break;
   }
   return new_ptr;
 }
 
-// heapinit.c
-intptr_t _get_heap_handle() {
-  return reinterpret_cast<intptr_t>(_crtheap);
-}
-
-// heapinit.c
-int _heap_init() {
-  base::allocator::g_is_win_shim_layer_initialized = true;
-  return win_heap_init() ? 1 : 0;
-}
-
-// heapinit.c
-void _heap_term() {
-  win_heap_term();
-}
-
-// calloc.c
-void* calloc(size_t n, size_t elem_size) {
+// Replaces calloc in ucrt\heap\calloc.cpp
+__declspec(restrict) void* calloc(size_t n, size_t elem_size) {
   // Overflow check.
   const size_t size = n * elem_size;
   if (elem_size != 0 && size / elem_size != n)
-    return NULL;
+    return nullptr;
 
   void* result = malloc(size);
-  if (result != NULL) {
+  if (result) {
     memset(result, 0, size);
   }
   return result;
 }
 
-// recalloc.c
-void* _recalloc(void* p, size_t n, size_t elem_size) {
-  if (!p)
-    return calloc(n, elem_size);
+}  // extern C
 
-  // This API is a bit odd.
-  // Note: recalloc only guarantees zeroed memory when p is NULL.
-  //   Generally, calls to malloc() have padding.  So a request
-  //   to malloc N bytes actually malloc's N+x bytes.  Later, if
-  //   that buffer is passed to recalloc, we don't know what N
-  //   was anymore.  We only know what N+x is.  As such, there is
-  //   no way to know what to zero out.
-  const size_t size = n * elem_size;
-  if (elem_size != 0 && size / elem_size != n)
-    return NULL;
-  return realloc(p, size);
-}
-
-// calloc_impl.c
-void* _calloc_impl(size_t n, size_t size) {
-  return calloc(n, size);
-}
-
-#ifndef NDEBUG
-#undef malloc
-#undef free
-#undef calloc
-
-static int error_handler(int reportType) {
-  switch (reportType) {
-    case 0:  // _CRT_WARN
-      __debugbreak();
-      return 0;
-
-    case 1:  // _CRT_ERROR
-      __debugbreak();
-      return 0;
-
-    case 2:  // _CRT_ASSERT
-      __debugbreak();
-      return 0;
-  }
-  char* p = NULL;
-  *p = '\0';
-  return 0;
-}
-
-int _CrtDbgReport(int reportType,
-                  const char*,
-                  int,
-                  const char*,
-                  const char*,
-                  ...) {
-  return error_handler(reportType);
-}
-
-int _CrtDbgReportW(int reportType,
-                   const wchar_t*,
-                   int,
-                   const wchar_t*,
-                   const wchar_t*,
-                   ...) {
-  return error_handler(reportType);
-}
-
-int _CrtSetReportMode(int, int) {
-  return 0;
-}
-
-void* _malloc_dbg(size_t size, int, const char*, int) {
-  return malloc(size);
-}
-
-void* _realloc_dbg(void* ptr, size_t size, int, const char*, int) {
-  return realloc(ptr, size);
-}
-
-void _free_dbg(void* ptr, int) {
-  free(ptr);
-}
-
-void* _calloc_dbg(size_t n, size_t size, int, const char*, int) {
-  return calloc(n, size);
-}
-#endif  // NDEBUG
-
-}  // extern C
+#endif  // defined(ALLOCATOR_SHIM)