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// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This file has been copied from //base/debug/alias.h (and then trimmed to just
// the APIs / macros needed by //build/rust/std; additionally the APIs were
// moved into the `build_rust_std` namespace).
//
// TODO(crbug.com/40279749): Avoid code duplication / reuse code.
#ifndef BUILD_RUST_ALLOCATOR_ALIAS_H_
#define BUILD_RUST_ALLOCATOR_ALIAS_H_
#include <stddef.h>
namespace build_rust_std {
namespace debug {
// Make the optimizer think that |var| is aliased. This can be used to prevent a
// local variable from being optimized out (which is something that
// `NO_CODE_FOLDING` macro definition below depends on). See
// //base/debug/alias.h for more details.
void Alias(const void* var);
} // namespace debug
} // namespace build_rust_std
// Prevent code folding (where a linker identifies functions that are
// bit-identical and overlays them, which saves space but it leads to confusing
// call stacks because multiple symbols are at the same address). See
// //base/debug/alias.h for more details.
#define NO_CODE_FOLDING() \
const int line_number = __LINE__; \
build_rust_std::debug::Alias(&line_number)
#endif // BUILD_RUST_ALLOCATOR_ALIAS_H_
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