clang-tools-extra/clangd/PathMapping.h

   1 //===--- PathMapping.h - 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
   9 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_PATHMAPPING_H
  10 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_PATHMAPPING_H
  11
  12 #include "llvm/ADT/StringRef.h"
  13 #include "llvm/Support/Error.h"
  14 #include "llvm/Support/JSON.h"
  15 #include "llvm/Support/raw_ostream.h"
  16 #include <memory>
  17 #include <optional>
  18 #include <string>
  19 #include <vector>
  20
  21 namespace clang {
  22 namespace clangd {
  23
  24 class Transport;
  25
  26 /// PathMappings are a collection of paired client and server paths.
  27 /// These pairs are used to alter file:// URIs appearing in inbound and outbound
  28 /// LSP messages, as the client's environment may have source files or
  29 /// dependencies at different locations than the server. Therefore, both
  30 /// paths are stored as they appear in file URI bodies, e.g. /usr/include or
  31 /// /C:/config
  32 ///
  33 /// For example, if the mappings were {{"/home/user", "/workarea"}}, then
  34 /// a client-to-server LSP message would have file:///home/user/foo.cpp
  35 /// remapped to file:///workarea/foo.cpp, and the same would happen for replies
  36 /// (in the opposite order).
  37 struct PathMapping {
  38   std::string ClientPath;
  39   std::string ServerPath;
  40   enum class Direction { ClientToServer, ServerToClient };
  41 };
  42 using PathMappings = std::vector<PathMapping>;
  43
  44 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const PathMapping &M);
  45
  46 /// Parse the command line \p RawPathMappings (e.g. "/client=/server") into
  47 /// pairs. Returns an error if the mappings are malformed, i.e. not absolute or
  48 /// not a proper pair.
  49 llvm::Expected<PathMappings> parsePathMappings(llvm::StringRef RawPathMappings);
  50
  51 /// Returns a modified \p S with the first matching path in \p Mappings
  52 /// substituted, if applicable
  53 std::optional<std::string> doPathMapping(llvm::StringRef S,
  54                                          PathMapping::Direction Dir,
  55                                          const PathMappings &Mappings);
  56
  57 /// Applies the \p Mappings to all the file:// URIs in \p Params.
  58 /// NOTE: The first matching mapping will be applied, otherwise \p Params will
  59 /// be untouched.
  60 void applyPathMappings(llvm::json::Value &Params, PathMapping::Direction Dir,
  61                        const PathMappings &Mappings);
  62
  63 /// Creates a wrapping transport over \p Transp that applies the \p Mappings to
  64 /// all inbound and outbound LSP messages. All calls are then delegated to the
  65 /// regular transport (e.g. XPC, JSON).
  66 std::unique_ptr<Transport>
  67 createPathMappingTransport(std::unique_ptr<Transport> Transp,
  68                            PathMappings Mappings);
  69
  70 } // namespace clangd
  71 } // namespace clang
  72
  73 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_PATHMAPPING_H