1//=== RegistryParser.h - Linker-supported plugin registries -----*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Defines a command-line parser for a registry.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_REGISTRYPARSER_H
15#define LLVM_SUPPORT_REGISTRYPARSER_H
16
17#include "llvm/Support/CommandLine.h"
18#include "llvm/Support/Registry.h"
19
20namespace llvm {
21
22  /// A command-line parser for a registry. Use like such:
23  ///
24  ///   static cl::opt<Registry<Collector>::entry, false,
25  ///                  RegistryParser<Collector> >
26  ///   GCOpt("gc", cl::desc("Garbage collector to use."),
27  ///               cl::value_desc());
28  ///
29  /// To make use of the value:
30  ///
31  ///   Collector *TheCollector = GCOpt->instantiate();
32  ///
33  template <typename T, typename U = RegistryTraits<T> >
34  class RegistryParser :
35  public cl::parser<const typename U::entry*>,
36    public Registry<T, U>::listener {
37    typedef U traits;
38    typedef typename U::entry entry;
39    typedef typename Registry<T, U>::listener listener;
40
41  protected:
42    void registered(const entry &E) {
43      addLiteralOption(traits::nameof(E), &E, traits::descof(E));
44    }
45
46  public:
47    void initialize(cl::Option &O) {
48      listener::init();
49      cl::parser<const typename U::entry*>::initialize(O);
50    }
51  };
52
53}
54
55#endif // LLVM_SUPPORT_REGISTRYPARSER_H
56