1*06c3fb27SDimitry Andric //===--- LazyDetector.h - Lazy ToolChain Detection --------------*- C++ -*-===// 2*06c3fb27SDimitry Andric // 3*06c3fb27SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*06c3fb27SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*06c3fb27SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*06c3fb27SDimitry Andric // 7*06c3fb27SDimitry Andric //===----------------------------------------------------------------------===// 8*06c3fb27SDimitry Andric 9*06c3fb27SDimitry Andric #ifndef LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H 10*06c3fb27SDimitry Andric #define LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H 11*06c3fb27SDimitry Andric 12*06c3fb27SDimitry Andric #include "clang/Driver/Tool.h" 13*06c3fb27SDimitry Andric #include "clang/Driver/ToolChain.h" 14*06c3fb27SDimitry Andric #include <optional> 15*06c3fb27SDimitry Andric 16*06c3fb27SDimitry Andric namespace clang { 17*06c3fb27SDimitry Andric 18*06c3fb27SDimitry Andric /// Simple wrapper for toolchain detector with costly initialization. This 19*06c3fb27SDimitry Andric /// delays the creation of the actual detector until its first usage. 20*06c3fb27SDimitry Andric 21*06c3fb27SDimitry Andric template <class T> class LazyDetector { 22*06c3fb27SDimitry Andric const driver::Driver &D; 23*06c3fb27SDimitry Andric llvm::Triple Triple; 24*06c3fb27SDimitry Andric const llvm::opt::ArgList &Args; 25*06c3fb27SDimitry Andric 26*06c3fb27SDimitry Andric std::optional<T> Detector; 27*06c3fb27SDimitry Andric 28*06c3fb27SDimitry Andric public: LazyDetector(const driver::Driver & D,const llvm::Triple & Triple,const llvm::opt::ArgList & Args)29*06c3fb27SDimitry Andric LazyDetector(const driver::Driver &D, const llvm::Triple &Triple, 30*06c3fb27SDimitry Andric const llvm::opt::ArgList &Args) 31*06c3fb27SDimitry Andric : D(D), Triple(Triple), Args(Args) {} 32*06c3fb27SDimitry Andric T *operator->() { 33*06c3fb27SDimitry Andric if (!Detector) 34*06c3fb27SDimitry Andric Detector.emplace(D, Triple, Args); 35*06c3fb27SDimitry Andric return &*Detector; 36*06c3fb27SDimitry Andric } 37*06c3fb27SDimitry Andric const T *operator->() const { 38*06c3fb27SDimitry Andric return const_cast<T const *>( 39*06c3fb27SDimitry Andric const_cast<LazyDetector &>(*this).operator->()); 40*06c3fb27SDimitry Andric } 41*06c3fb27SDimitry Andric }; 42*06c3fb27SDimitry Andric 43*06c3fb27SDimitry Andric } // end namespace clang 44*06c3fb27SDimitry Andric 45*06c3fb27SDimitry Andric #endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H 46