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 "support/Logger.h"
12 #include "llvm/Support/Error.h"
13 #include "llvm/Support/Path.h"
14 #include <algorithm>
15 #include <optional>
16 #include <tuple>
17
18 namespace clang {
19 namespace clangd {
doPathMapping(llvm::StringRef S,PathMapping::Direction Dir,const PathMappings & Mappings)20 std::optional<std::string> doPathMapping(llvm::StringRef S,
21 PathMapping::Direction Dir,
22 const PathMappings &Mappings) {
23 // Return early to optimize for the common case, wherein S is not a file URI
24 if (!S.starts_with("file://"))
25 return std::nullopt;
26 auto Uri = URI::parse(S);
27 if (!Uri) {
28 llvm::consumeError(Uri.takeError());
29 return std::nullopt;
30 }
31 for (const auto &Mapping : Mappings) {
32 const std::string &From = Dir == PathMapping::Direction::ClientToServer
33 ? Mapping.ClientPath
34 : Mapping.ServerPath;
35 const std::string &To = Dir == PathMapping::Direction::ClientToServer
36 ? Mapping.ServerPath
37 : Mapping.ClientPath;
38 llvm::StringRef Body = Uri->body();
39 if (Body.consume_front(From) && (Body.empty() || Body.front() == '/')) {
40 std::string MappedBody = (To + Body).str();
41 return URI(Uri->scheme(), Uri->authority(), MappedBody)
42 .toString();
43 }
44 }
45 return std::nullopt;
46 }
47
applyPathMappings(llvm::json::Value & V,PathMapping::Direction Dir,const PathMappings & Mappings)48 void applyPathMappings(llvm::json::Value &V, PathMapping::Direction Dir,
49 const PathMappings &Mappings) {
50 using Kind = llvm::json::Value::Kind;
51 Kind K = V.kind();
52 if (K == Kind::Object) {
53 llvm::json::Object *Obj = V.getAsObject();
54 llvm::json::Object MappedObj;
55 // 1. Map all the Keys
56 for (auto &KV : *Obj) {
57 if (std::optional<std::string> MappedKey =
58 doPathMapping(KV.first.str(), Dir, Mappings)) {
59 MappedObj.try_emplace(std::move(*MappedKey), std::move(KV.second));
60 } else {
61 MappedObj.try_emplace(std::move(KV.first), std::move(KV.second));
62 }
63 }
64 *Obj = std::move(MappedObj);
65 // 2. Map all the values
66 for (auto &KV : *Obj)
67 applyPathMappings(KV.second, Dir, Mappings);
68 } else if (K == Kind::Array) {
69 for (llvm::json::Value &Val : *V.getAsArray())
70 applyPathMappings(Val, Dir, Mappings);
71 } else if (K == Kind::String) {
72 if (std::optional<std::string> Mapped =
73 doPathMapping(*V.getAsString(), Dir, Mappings))
74 V = std::move(*Mapped);
75 }
76 }
77
78 namespace {
79
80 class PathMappingMessageHandler : public Transport::MessageHandler {
81 public:
PathMappingMessageHandler(MessageHandler & Handler,const PathMappings & Mappings)82 PathMappingMessageHandler(MessageHandler &Handler,
83 const PathMappings &Mappings)
84 : WrappedHandler(Handler), Mappings(Mappings) {}
85
onNotify(llvm::StringRef Method,llvm::json::Value Params)86 bool onNotify(llvm::StringRef Method, llvm::json::Value Params) override {
87 applyPathMappings(Params, PathMapping::Direction::ClientToServer, Mappings);
88 return WrappedHandler.onNotify(Method, std::move(Params));
89 }
90
onCall(llvm::StringRef Method,llvm::json::Value Params,llvm::json::Value ID)91 bool onCall(llvm::StringRef Method, llvm::json::Value Params,
92 llvm::json::Value ID) override {
93 applyPathMappings(Params, PathMapping::Direction::ClientToServer, Mappings);
94 return WrappedHandler.onCall(Method, std::move(Params), std::move(ID));
95 }
96
onReply(llvm::json::Value ID,llvm::Expected<llvm::json::Value> Result)97 bool onReply(llvm::json::Value ID,
98 llvm::Expected<llvm::json::Value> Result) override {
99 if (Result)
100 applyPathMappings(*Result, PathMapping::Direction::ClientToServer,
101 Mappings);
102 return WrappedHandler.onReply(std::move(ID), std::move(Result));
103 }
104
105 private:
106 Transport::MessageHandler &WrappedHandler;
107 const PathMappings &Mappings;
108 };
109
110 // Apply path mappings to all LSP messages by intercepting all params/results
111 // and then delegating to the normal transport
112 class PathMappingTransport : public Transport {
113 public:
PathMappingTransport(std::unique_ptr<Transport> Transp,PathMappings Mappings)114 PathMappingTransport(std::unique_ptr<Transport> Transp, PathMappings Mappings)
115 : WrappedTransport(std::move(Transp)), Mappings(std::move(Mappings)) {}
116
notify(llvm::StringRef Method,llvm::json::Value Params)117 void notify(llvm::StringRef Method, llvm::json::Value Params) override {
118 applyPathMappings(Params, PathMapping::Direction::ServerToClient, Mappings);
119 WrappedTransport->notify(Method, std::move(Params));
120 }
121
call(llvm::StringRef Method,llvm::json::Value Params,llvm::json::Value ID)122 void call(llvm::StringRef Method, llvm::json::Value Params,
123 llvm::json::Value ID) override {
124 applyPathMappings(Params, PathMapping::Direction::ServerToClient, Mappings);
125 WrappedTransport->call(Method, std::move(Params), std::move(ID));
126 }
127
reply(llvm::json::Value ID,llvm::Expected<llvm::json::Value> Result)128 void reply(llvm::json::Value ID,
129 llvm::Expected<llvm::json::Value> Result) override {
130 if (Result)
131 applyPathMappings(*Result, PathMapping::Direction::ServerToClient,
132 Mappings);
133 WrappedTransport->reply(std::move(ID), std::move(Result));
134 }
135
loop(MessageHandler & Handler)136 llvm::Error loop(MessageHandler &Handler) override {
137 PathMappingMessageHandler WrappedHandler(Handler, Mappings);
138 return WrappedTransport->loop(WrappedHandler);
139 }
140
141 private:
142 std::unique_ptr<Transport> WrappedTransport;
143 PathMappings Mappings;
144 };
145
146 // Converts a unix/windows path to the path portion of a file URI
147 // e.g. "C:\foo" -> "/C:/foo"
parsePath(llvm::StringRef Path)148 llvm::Expected<std::string> parsePath(llvm::StringRef Path) {
149 namespace path = llvm::sys::path;
150 if (path::is_absolute(Path, path::Style::posix)) {
151 return std::string(Path);
152 }
153 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 error("Path not absolute: {0}", Path);
160 }
161
162 } // namespace
163
operator <<(llvm::raw_ostream & OS,const PathMapping & M)164 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const PathMapping &M) {
165 return OS << M.ClientPath << "=" << M.ServerPath;
166 }
167
168 llvm::Expected<PathMappings>
parsePathMappings(llvm::StringRef RawPathMappings)169 parsePathMappings(llvm::StringRef RawPathMappings) {
170 llvm::StringRef ClientPath, ServerPath, PathPair, Rest = RawPathMappings;
171 PathMappings ParsedMappings;
172 while (!Rest.empty()) {
173 std::tie(PathPair, Rest) = Rest.split(",");
174 std::tie(ClientPath, ServerPath) = PathPair.split("=");
175 if (ClientPath.empty() || ServerPath.empty())
176 return error("Not a valid path mapping pair: {0}", PathPair);
177 llvm::Expected<std::string> ParsedClientPath = parsePath(ClientPath);
178 if (!ParsedClientPath)
179 return ParsedClientPath.takeError();
180 llvm::Expected<std::string> ParsedServerPath = parsePath(ServerPath);
181 if (!ParsedServerPath)
182 return ParsedServerPath.takeError();
183 ParsedMappings.push_back(
184 {std::move(*ParsedClientPath), std::move(*ParsedServerPath)});
185 }
186 return ParsedMappings;
187 }
188
189 std::unique_ptr<Transport>
createPathMappingTransport(std::unique_ptr<Transport> Transp,PathMappings Mappings)190 createPathMappingTransport(std::unique_ptr<Transport> Transp,
191 PathMappings Mappings) {
192 return std::make_unique<PathMappingTransport>(std::move(Transp), Mappings);
193 }
194
195 } // namespace clangd
196 } // namespace clang
197