| 1 | //===- StripSwiftForceLoad.h ------------------------------------*- C++ -*-===// |
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #ifndef LLD_MACHO_STRIP_SWIFT_FORCE_LOAD_H |
| 10 | #define LLD_MACHO_STRIP_SWIFT_FORCE_LOAD_H |
| 11 | |
| 12 | namespace lld::macho { |
| 13 | |
| 14 | // Drop `__DATA,__const` sections that exist only to force-load Swift overlays. |
| 15 | // |
| 16 | // The Swift compiler emits `__swift_FORCE_LOAD_$_swift<overlay>` pointers in |
| 17 | // `__DATA,__const` that bind to the imported symbol of the same name in a |
| 18 | // dependent overlay dylib. These pointers are never dereferenced -- they exist |
| 19 | // only to keep the overlay dylib linked in. When a section consists entirely of |
| 20 | // such pointers (and is not anchored by any externally visible symbol clients |
| 21 | // might link against), this pass drops the whole section, reclaiming its bytes |
| 22 | // and removing the dyld binds. |
| 23 | // |
| 24 | // The imported FORCE_LOAD DylibSymbols are intentionally left referenced, so |
| 25 | // the overlays' LC_LOAD_DYLIB dependencies are preserved. |
| 26 | // |
| 27 | // NOTE: Must be run after markLive(). |
| 28 | void stripSwiftForceLoadFixups(); |
| 29 | |
| 30 | } // namespace lld::macho |
| 31 | |
| 32 | #endif |
| 33 | |