| // 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_ |
