1 //===--- PathMapping.cpp - apply path mappings to LSP messages -===//
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 "PathMapping.h"
9 #include "Transport.h"
10 #include "URI.h"
11 #include "llvm/ADT/None.h"
12 #include "llvm/ADT/STLExtras.h"
13 #include "llvm/Support/Errno.h"
14 #include "llvm/Support/Error.h"
15 #include "llvm/Support/Path.h"
16 #include <algorithm>
17 #include <tuple>
18
19 namespace clang {
20 namespace clangd {
doPathMapping(llvm::StringRef S,PathMapping::Direction Dir,const PathMappings & Mappings)21 llvm::Optional<std::string> doPathMapping(llvm::StringRef S,
22 PathMapping::Direction Dir,
23 const PathMappings &Mappings) {
24 // Return early to optimize for the common case, wherein S is not a file URI
25 if (!S.startswith("file://"))
26 return llvm::None;
27 auto Uri = URI::parse(S);
28 if (!Uri) {
29 llvm::consumeError(Uri.takeError());
30 return llvm::None;
31 }
32 for (const auto &Mapping : Mappings) {
33 const std::string &From = Dir == PathMapping::Direction::ClientToServer
34 ? Mapping.ClientPath
35 : Mapping.ServerPath;
36 const std::string &To = Dir == PathMapping::Direction::ClientToServer
37 ? Mapping.ServerPath
38 : Mapping.ClientPath;
39 llvm::StringRef Body = Uri->body();
40 if (Body.consume_front(From) && (Body.empty() || Body.front() == '/')) {
41 std::string MappedBody = (To + Body).str();
42 return URI(Uri->scheme(), Uri->authority(), MappedBody.c_str())
43 .toString();
44 }
45 }
46 return llvm::None;
47 }
48
applyPathMappings(llvm::json::Value & V,PathMapping::Direction Dir,const PathMappings & Mappings)49 void applyPathMappings(llvm::json::Value &V, PathMapping::Direction Dir,
50 const PathMappings &Mappings) {
51 using Kind = llvm::json::Value::Kind;
52 Kind K = V.kind();
53 if (K == Kind::Object) {
54 llvm::json::Object *Obj = V.getAsObject();
55 llvm::json::Object MappedObj;
56 // 1. Map all the Keys
57 for (auto &KV : *Obj) {
58 if (llvm::Optional<std::string> MappedKey =
59 doPathMapping(KV.first.str(), Dir, Mappings)) {
60 MappedObj.try_emplace(std::move(*MappedKey), std::move(KV.second));
61 } else {
62 MappedObj.try_emplace(std::move(KV.first), std::move(KV.second));
63 }
64 }
65 *Obj = std::move(MappedObj);
66 // 2. Map all the values
67 for (auto &KV : *Obj)
68 applyPathMappings(KV.second, Dir, Mappings);
69 } else if (K == Kind::Array) {
70 for (llvm::json::Value &Val : *V.getAsArray())
71 applyPathMappings(Val, Dir, Mappings);
72 } else if (K == Kind::String) {
73 if (llvm::Optional<std::string> Mapped =
74 doPathMapping(*V.getAsString(), Dir, Mappings))
75 V = std::move(*Mapped);
76 }
77 }
78
79 namespace {
80
81 class PathMappingMessageHandler : public Transport::MessageHandler {
82 public:
PathMappingMessageHandler(MessageHandler & Handler,const PathMappings & Mappings)83 PathMappingMessageHandler(MessageHandler &Handler,
84 const PathMappings &Mappings)
85 : WrappedHandler(Handler), Mappings(Mappings) {}
86
onNotify(llvm::StringRef Method,llvm::json::Value Params)87 bool onNotify(llvm::StringRef Method, llvm::json::Value Params) override {
88 applyPathMappings(Params, PathMapping::Direction::ClientToServer, Mappings);
89 return WrappedHandler.onNotify(Method, std::move(Params));
90 }
91
onCall(llvm::StringRef Method,llvm::json::Value Params,llvm::json::Value ID)92 bool onCall(llvm::StringRef Method, llvm::json::Value Params,
93 llvm::json::Value ID) override {
94 applyPathMappings(Params, PathMapping::Direction::ClientToServer, Mappings);
95 return WrappedHandler.onCall(Method, std::move(Params), std::move(ID));
96 }
97
onReply(llvm::json::Value ID,llvm::Expected<llvm::json::Value> Result)98 bool onReply(llvm::json::Value ID,
99 llvm::Expected<llvm::json::Value> Result) override {
100 if (Result)
101 applyPathMappings(*Result, PathMapping::Direction::ClientToServer,
102 Mappings);
103 return WrappedHandler.onReply(std::move(ID), std::move(Result));
104 }
105
106 private:
107 Transport::MessageHandler &WrappedHandler;
108 const PathMappings &Mappings;
109 };
110
111 // Apply path mappings to all LSP messages by intercepting all params/results
112 // and then delegating to the normal transport
113 class PathMappingTransport : public Transport {
114 public:
PathMappingTransport(std::unique_ptr<Transport> Transp,PathMappings Mappings)115 PathMappingTransport(std::unique_ptr<Transport> Transp, PathMappings Mappings)
116 : WrappedTransport(std::move(Transp)), Mappings(std::move(Mappings)) {}
117
notify(llvm::StringRef Method,llvm::json::Value Params)118 void notify(llvm::StringRef Method, llvm::json::Value Params) override {
119 applyPathMappings(Params, PathMapping::Direction::ServerToClient, Mappings);
120 WrappedTransport->notify(Method, std::move(Params));
121 }
122
call(llvm::StringRef Method,llvm::json::Value Params,llvm::json::Value ID)123 void call(llvm::StringRef Method, llvm::json::Value Params,
124 llvm::json::Value ID) override {
125 applyPathMappings(Params, PathMapping::Direction::ServerToClient, Mappings);
126 WrappedTransport->call(Method, std::move(Params), std::move(ID));
127 }
128
reply(llvm::json::Value ID,llvm::Expected<llvm::json::Value> Result)129 void reply(llvm::json::Value ID,
130 llvm::Expected<llvm::json::Value> Result) override {
131 if (Result)
132 applyPathMappings(*Result, PathMapping::Direction::ServerToClient,
133 Mappings);
134 WrappedTransport->reply(std::move(ID), std::move(Result));
135 }
136
loop(MessageHandler & Handler)137 llvm::Error loop(MessageHandler &Handler) override {
138 PathMappingMessageHandler WrappedHandler(Handler, Mappings);
139 return WrappedTransport->loop(WrappedHandler);
140 }
141
142 private:
143 std::unique_ptr<Transport> WrappedTransport;
144 PathMappings Mappings;
145 };
146
147 // Converts a unix/windows path to the path portion of a file URI
148 // e.g. "C:\foo" -> "/C:/foo"
parsePath(llvm::StringRef Path)149 llvm::Expected<std::string> parsePath(llvm::StringRef Path) {
150 namespace path = llvm::sys::path;
151 if (path::is_absolute(Path, path::Style::posix)) {
152 return std::string(Path);
153 } else if (path::is_absolute(Path, path::Style::windows)) {
154 std::string Converted = path::convert_to_slash(Path, path::Style::windows);
155 if (Converted.front() != '/')
156 Converted = "/" + Converted;
157 return Converted;
158 }
159 return llvm::createStringError(llvm::inconvertibleErrorCode(),
160 "Path not absolute: " + Path);
161 }
162
163 } // namespace
164
operator <<(llvm::raw_ostream & OS,const PathMapping & M)165 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const PathMapping &M) {
166 return OS << M.ClientPath << "=" << M.ServerPath;
167 }
168
169 llvm::Expected<PathMappings>
parsePathMappings(llvm::StringRef RawPathMappings)170 parsePathMappings(llvm::StringRef RawPathMappings) {
171 llvm::StringRef ClientPath, ServerPath, PathPair, Rest = RawPathMappings;
172 PathMappings ParsedMappings;
173 while (!Rest.empty()) {
174 std::tie(PathPair, Rest) = Rest.split(",");
175 std::tie(ClientPath, ServerPath) = PathPair.split("=");
176 if (ClientPath.empty() || ServerPath.empty())
177 return llvm::createStringError(llvm::inconvertibleErrorCode(),
178 "Not a valid path mapping pair: " +
179 PathPair);
180 llvm::Expected<std::string> ParsedClientPath = parsePath(ClientPath);
181 if (!ParsedClientPath)
182 return ParsedClientPath.takeError();
183 llvm::Expected<std::string> ParsedServerPath = parsePath(ServerPath);
184 if (!ParsedServerPath)
185 return ParsedServerPath.takeError();
186 ParsedMappings.push_back(
187 {std::move(*ParsedClientPath), std::move(*ParsedServerPath)});
188 }
189 return ParsedMappings;
190 }
191
192 std::unique_ptr<Transport>
createPathMappingTransport(std::unique_ptr<Transport> Transp,PathMappings Mappings)193 createPathMappingTransport(std::unique_ptr<Transport> Transp,
194 PathMappings Mappings) {
195 return std::make_unique<PathMappingTransport>(std::move(Transp), Mappings);
196 }
197
198 } // namespace clangd
199 } // namespace clang
200