1 | //===----------------- ModulesBuilder.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 | // Experimental support for C++20 Modules. |
10 | // |
11 | // Currently we simplify the implementations by preventing reusing module files |
12 | // across different versions and different source files. But this is clearly a |
13 | // waste of time and space in the end of the day. |
14 | // |
15 | // TODO: Supporting reusing module files across different versions and |
16 | // different source files. |
17 | // |
18 | //===----------------------------------------------------------------------===// |
19 | |
20 | #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_MODULES_BUILDER_H |
21 | #define |
22 | |
23 | #include "GlobalCompilationDatabase.h" |
24 | #include "ProjectModules.h" |
25 | #include "support/Path.h" |
26 | #include "support/ThreadsafeFS.h" |
27 | #include "clang/Frontend/CompilerInvocation.h" |
28 | #include "llvm/ADT/SmallString.h" |
29 | #include <memory> |
30 | |
31 | namespace clang { |
32 | namespace clangd { |
33 | |
34 | /// Store all the needed module files information to parse a single |
35 | /// source file. e.g., |
36 | /// |
37 | /// ``` |
38 | /// // a.cppm |
39 | /// export module a; |
40 | /// |
41 | /// // b.cppm |
42 | /// export module b; |
43 | /// import a; |
44 | /// |
45 | /// // c.cppm |
46 | /// export module c; |
47 | /// import b; |
48 | /// ``` |
49 | /// |
50 | /// For the source file `c.cppm`, an instance of the class will store |
51 | /// the module files for `a.cppm` and `b.cppm`. But the module file for `c.cppm` |
52 | /// won't be stored. Since it is not needed to parse `c.cppm`. |
53 | /// |
54 | /// Users should only get PrerequisiteModules from |
55 | /// `ModulesBuilder::buildPrerequisiteModulesFor(...)`. |
56 | /// |
57 | /// Users can detect whether the PrerequisiteModules is still up to date by |
58 | /// calling the `canReuse()` member function. |
59 | /// |
60 | /// The users should call `adjustHeaderSearchOptions(...)` to update the |
61 | /// compilation commands to select the built module files first. Before calling |
62 | /// `adjustHeaderSearchOptions()`, users should call `canReuse()` first to check |
63 | /// if all the stored module files are valid. In case they are not valid, |
64 | /// users should call `ModulesBuilder::buildPrerequisiteModulesFor(...)` again |
65 | /// to get the new PrerequisiteModules. |
66 | class PrerequisiteModules { |
67 | public: |
68 | /// Change commands to load the module files recorded in this |
69 | /// PrerequisiteModules first. |
70 | virtual void |
71 | (HeaderSearchOptions &Options) const = 0; |
72 | |
73 | /// Whether or not the built module files are up to date. |
74 | /// Note that this can only be used after building the module files. |
75 | virtual bool |
76 | canReuse(const CompilerInvocation &CI, |
77 | llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) const = 0; |
78 | |
79 | virtual ~PrerequisiteModules() = default; |
80 | }; |
81 | |
82 | /// This class handles building module files for a given source file. |
83 | /// |
84 | /// In the future, we want the class to manage the module files acorss |
85 | /// different versions and different source files. |
86 | class ModulesBuilder { |
87 | public: |
88 | ModulesBuilder(const GlobalCompilationDatabase &CDB); |
89 | ~ModulesBuilder(); |
90 | |
91 | ModulesBuilder(const ModulesBuilder &) = delete; |
92 | ModulesBuilder(ModulesBuilder &&) = delete; |
93 | |
94 | ModulesBuilder &operator=(const ModulesBuilder &) = delete; |
95 | ModulesBuilder &operator=(ModulesBuilder &&) = delete; |
96 | |
97 | std::unique_ptr<PrerequisiteModules> |
98 | buildPrerequisiteModulesFor(PathRef File, const ThreadsafeFS &TFS); |
99 | |
100 | private: |
101 | class ModulesBuilderImpl; |
102 | std::unique_ptr<ModulesBuilderImpl> Impl; |
103 | }; |
104 | |
105 | } // namespace clangd |
106 | } // namespace clang |
107 | |
108 | #endif |
109 | |