| 1 | //===--- LazyDetector.h - Lazy ToolChain Detection --------------*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #ifndef LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H |
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| 10 | #define LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H |
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| 11 | |
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| 12 | #include "clang/Driver/Tool.h" |
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| 13 | #include "clang/Driver/ToolChain.h" |
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| 14 | #include <optional> |
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| 15 | |
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| 16 | namespace clang { |
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| 17 | |
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| 18 | /// Simple wrapper for toolchain detector with costly initialization. This |
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| 19 | /// delays the creation of the actual detector until its first usage. |
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| 20 | |
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| 21 | template <class T> class LazyDetector { |
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| 22 | const driver::Driver &D; |
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| 23 | llvm::Triple Triple; |
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| 24 | const llvm::opt::ArgList &Args; |
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| 25 | |
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| 26 | std::optional<T> Detector; |
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| 27 | |
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| 28 | public: |
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| 29 | LazyDetector(const driver::Driver &D, const llvm::Triple &Triple, |
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| 30 | const llvm::opt::ArgList &Args) |
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| 31 | : D(D), Triple(Triple), Args(Args) {} |
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| 32 | T *operator->() { |
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| 33 | if (!Detector) |
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| 34 | Detector.emplace(D, Triple, Args); |
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| 35 | return &*Detector; |
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| 36 | } |
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| 37 | const T *operator->() const { |
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| 38 | return const_cast<T const *>( |
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| 39 | const_cast<LazyDetector &>(*this).operator->()); |
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| 40 | } |
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| 41 | }; |
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| 42 | |
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| 43 | } // end namespace clang |
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| 44 | |
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| 45 | #endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H |
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| 46 | |
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