1 //===--- Tweak.cpp -----------------------------------------------*- 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 #include "Tweak.h"
9 #include "FeatureModule.h"
10 #include "SourceCode.h"
11 #include "index/Index.h"
12 #include "support/Logger.h"
13 #include "support/Path.h"
14 #include "llvm/ADT/None.h"
15 #include "llvm/ADT/Optional.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/StringMap.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/Support/Error.h"
20 #include "llvm/Support/Registry.h"
21 #include <functional>
22 #include <memory>
23 #include <utility>
24 #include <vector>
25 
26 LLVM_INSTANTIATE_REGISTRY(llvm::Registry<clang::clangd::Tweak>)
27 
28 namespace clang {
29 namespace clangd {
30 
31 /// A handy typedef to save some typing.
32 typedef llvm::Registry<Tweak> TweakRegistry;
33 
34 namespace {
35 /// Asserts invariants on TweakRegistry. No-op with assertion disabled.
36 void validateRegistry() {
37 #ifndef NDEBUG
38   llvm::StringSet<> Seen;
39   for (const auto &E : TweakRegistry::entries()) {
40     // REGISTER_TWEAK ensures E.getName() is equal to the tweak class name.
41     // We check that id() matches it.
42     assert(E.instantiate()->id() == E.getName() &&
43            "id should be equal to class name");
44     assert(Seen.try_emplace(E.getName()).second && "duplicate check id");
45   }
46 #endif
47 }
48 
49 std::vector<std::unique_ptr<Tweak>>
50 getAllTweaks(const FeatureModuleSet *Modules) {
51   std::vector<std::unique_ptr<Tweak>> All;
52   for (const auto &E : TweakRegistry::entries())
53     All.emplace_back(E.instantiate());
54   if (Modules) {
55     for (auto &M : *Modules)
56       M.contributeTweaks(All);
57   }
58   return All;
59 }
60 } // namespace
61 
62 Tweak::Selection::Selection(const SymbolIndex *Index, ParsedAST &AST,
63                             unsigned RangeBegin, unsigned RangeEnd,
64                             SelectionTree ASTSelection,
65                             llvm::vfs::FileSystem *FS)
66     : Index(Index), AST(&AST), SelectionBegin(RangeBegin),
67       SelectionEnd(RangeEnd), ASTSelection(std::move(ASTSelection)), FS(FS) {
68   auto &SM = AST.getSourceManager();
69   Code = SM.getBufferData(SM.getMainFileID());
70   Cursor = SM.getComposedLoc(SM.getMainFileID(), RangeBegin);
71 }
72 
73 std::vector<std::unique_ptr<Tweak>>
74 prepareTweaks(const Tweak::Selection &S,
75               llvm::function_ref<bool(const Tweak &)> Filter,
76               const FeatureModuleSet *Modules) {
77   validateRegistry();
78 
79   std::vector<std::unique_ptr<Tweak>> Available;
80   for (auto &T : getAllTweaks(Modules)) {
81     if (!Filter(*T) || !T->prepare(S))
82       continue;
83     Available.push_back(std::move(T));
84   }
85   // Ensure deterministic order of the results.
86   llvm::sort(Available,
87              [](const std::unique_ptr<Tweak> &L,
88                 const std::unique_ptr<Tweak> &R) { return L->id() < R->id(); });
89   return Available;
90 }
91 
92 llvm::Expected<std::unique_ptr<Tweak>>
93 prepareTweak(StringRef ID, const Tweak::Selection &S,
94              const FeatureModuleSet *Modules) {
95   for (auto &T : getAllTweaks(Modules)) {
96     if (T->id() != ID)
97       continue;
98     if (!T->prepare(S))
99       return error("failed to prepare() tweak {0}", ID);
100     return std::move(T);
101   }
102   return error("tweak ID {0} is invalid", ID);
103 }
104 
105 llvm::Expected<std::pair<Path, Edit>>
106 Tweak::Effect::fileEdit(const SourceManager &SM, FileID FID,
107                         tooling::Replacements Replacements) {
108   Edit Ed(SM.getBufferData(FID), std::move(Replacements));
109   if (auto FilePath = getCanonicalPath(SM.getFileEntryForID(FID), SM))
110     return std::make_pair(*FilePath, std::move(Ed));
111   return error("Failed to get absolute path for edited file: {0}",
112                SM.getFileEntryForID(FID)->getName());
113 }
114 
115 llvm::Expected<Tweak::Effect>
116 Tweak::Effect::mainFileEdit(const SourceManager &SM,
117                             tooling::Replacements Replacements) {
118   auto PathAndEdit = fileEdit(SM, SM.getMainFileID(), std::move(Replacements));
119   if (!PathAndEdit)
120     return PathAndEdit.takeError();
121   Tweak::Effect E;
122   E.ApplyEdits.try_emplace(PathAndEdit->first, PathAndEdit->second);
123   return E;
124 }
125 
126 } // namespace clangd
127 } // namespace clang
128