1//===--- LazyDetector.h - Lazy ToolChain Detection --------------*- 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 LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H
10#define LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H
11
12#include "clang/Driver/Tool.h"
13#include "clang/Driver/ToolChain.h"
14#include <optional>
15
16namespace clang {
17
18/// Simple wrapper for toolchain detector with costly initialization. This
19/// delays the creation of the actual detector until its first usage.
20
21template <class T> class LazyDetector {
22 const driver::Driver &D;
23 llvm::Triple Triple;
24 const llvm::opt::ArgList &Args;
25
26 std::optional<T> Detector;
27
28public:
29 LazyDetector(const driver::Driver &D, const llvm::Triple &Triple,
30 const llvm::opt::ArgList &Args)
31 : D(D), Triple(Triple), Args(Args) {}
32 T *operator->() {
33 if (!Detector)
34 Detector.emplace(D, Triple, Args);
35 return &*Detector;
36 }
37 const T *operator->() const {
38 return const_cast<T const *>(
39 const_cast<LazyDetector &>(*this).operator->());
40 }
41};
42
43} // end namespace clang
44
45#endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_LAZYDETECTOR_H
46