Support textDocument/{formatting,onTypeFormatting,rangeFormatting}

CMakeLists.txt

@@ -222,6 +222,7 @@ target_sources(ccls PRIVATE
   src/messages/textDocument_completion.cc
   src/messages/textDocument_definition.cc
   src/messages/textDocument_did.cc
+  src/messages/textDocument_formatting.cc
   src/messages/textDocument_documentHighlight.cc
   src/messages/textDocument_documentSymbol.cc
   src/messages/textDocument_hover.cc

README.md

@@ -8,6 +8,7 @@ ccls, which originates from [cquery](https://github.com/cquery-project/cquery),
   * code completion (with both signature help and snippets)
   * [definition](src/messages/textDocument_definition.cc)/[references](src/messages/textDcument_references.cc), and other cross references
   * cross reference extensions: `$ccls/call` `$ccls/inheritance` `$ccls/member` `$ccls/vars` ...
+  * formatting
   * hierarchies: [call (caller/callee) hierarchy](src/messages/ccls_call.cc), [inheritance (base/derived) hierarchy](src/messages/ccls_inheritance.cc), [member hierarchy](src/messages/ccls_member.cc)
   * [symbol rename](src/messages/textDocument_rename.cc)
   * [document symbols](src/messages/textDocument_documentSymbol.cc) and approximate search of [workspace symbol](src/messages/workspace_symbol.cc)
@@ -22,7 +23,7 @@ Saving files will incrementally update the index.
 
 Compared with cquery, it makes use of C++17 features, has less third-party dependencies and slimmed-down code base.
 It leverages Clang C++ API as [clangd](https://clang.llvm.org/extra/clangd.html) does, which provides better support for code completion and diagnostics.
-Refactoring and formatting are non-goals as they can be provided by clang-format, clang-include-fixer and other Clang based tools.
+Refactoring is a non-goal as it can be provided by clang-include-fixer and other Clang based tools.
 
 The comparison with cquery as noted on 2018-07-15:
 

cmake/FindClang.cmake

@@ -69,7 +69,17 @@ set(_Clang_REQUIRED_VARS Clang_LIBRARY Clang_INCLUDE_DIR Clang_EXECUTABLE
                          LLVM_INCLUDE_DIR LLVM_BUILD_INCLUDE_DIR)
 
 _Clang_find_library(Clang_LIBRARY clangIndex)
+_Clang_find_add_library(clangFormat)
 _Clang_find_add_library(clangTooling)
+
+# TODO Remove after dropping clang 6
+_Clang_find_library(clangToolingInclusions_LIBRARY clangToolingInclusions)
+if (clangToolingInclusions_LIBRARY)
+  list(APPEND _Clang_LIBRARIES ${clangToolingInclusions_LIBRARY})
+endif()
+
+_Clang_find_add_library(clangToolingCore)
+_Clang_find_add_library(clangRewrite)
 _Clang_find_add_library(clangFrontend)
 _Clang_find_add_library(clangParse)
 _Clang_find_add_library(clangSerialization)

src/messages/initialize.cc

@@ -54,7 +54,7 @@ MAKE_REFLECT_STRUCT(lsCompletionOptions, resolveProvider, triggerCharacters);
 // Format document on type options
 struct lsDocumentOnTypeFormattingOptions {
   // A character on which formatting should be triggered, like `}`.
-  std::string firstTriggerCharacter;
+  std::string firstTriggerCharacter = "}";
 
   // More trigger characters.
   std::vector<std::string> moreTriggerCharacter;
@@ -65,7 +65,7 @@ MAKE_REFLECT_STRUCT(lsDocumentOnTypeFormattingOptions, firstTriggerCharacter,
 // Document link options
 struct lsDocumentLinkOptions {
   // Document links have a resolve provider as well.
-  bool resolveProvider = true;
+  bool resolveProvider = false;
 };
 MAKE_REFLECT_STRUCT(lsDocumentLinkOptions, resolveProvider);
 
@@ -158,12 +158,11 @@ struct lsServerCapabilities {
   // The server provides code lens.
   lsCodeLensOptions codeLensProvider;
   // The server provides document formatting.
-  bool documentFormattingProvider = false;
+  bool documentFormattingProvider = true;
   // The server provides document range formatting.
-  bool documentRangeFormattingProvider = false;
+  bool documentRangeFormattingProvider = true;
   // The server provides document formatting on typing.
-  std::optional<lsDocumentOnTypeFormattingOptions>
-      documentOnTypeFormattingProvider;
+  lsDocumentOnTypeFormattingOptions documentOnTypeFormattingProvider;
   // The server provides rename support.
   bool renameProvider = true;
   // The server provides document link support.

src/messages/textDocument_formatting.cc

@@ -0,0 +1,192 @@
+// Copyright 2017-2018 ccls Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include "message_handler.h"
+#include "pipeline.hh"
+#include "working_files.h"
+
+#include <clang/Format/Format.h>
+#include <clang/Tooling/Core/Replacement.h>
+
+using namespace ccls;
+using namespace clang;
+
+namespace {
+const MethodType formatting = "textDocument/formatting",
+                 onTypeFormatting = "textDocument/onTypeFormatting",
+                 rangeFormatting = "textDocument/rangeFormatting";
+
+struct lsFormattingOptions {
+  // Size of a tab in spaces.
+  int tabSize;
+  // Prefer spaces over tabs.
+  bool insertSpaces;
+};
+MAKE_REFLECT_STRUCT(lsFormattingOptions, tabSize, insertSpaces);
+
+struct Out_TextDocumentFormatting
+    : public lsOutMessage<Out_TextDocumentFormatting> {
+  lsRequestId id;
+  std::vector<lsTextEdit> result;
+};
+MAKE_REFLECT_STRUCT(Out_TextDocumentFormatting, jsonrpc, id, result);
+
+llvm::Expected<tooling::Replacements>
+FormatCode(std::string_view code, std::string_view file, tooling::Range Range) {
+  StringRef Code(code.data(), code.size()), File(file.data(), file.size());
+  auto Style = format::getStyle("file", File, "LLVM", Code, nullptr);
+  if (!Style)
+    return Style.takeError();
+  tooling::Replacements IncludeReplaces =
+      format::sortIncludes(*Style, Code, {Range}, File);
+  auto Changed = tooling::applyAllReplacements(Code, IncludeReplaces);
+  if (!Changed)
+    return Changed.takeError();
+  return IncludeReplaces.merge(format::reformat(
+      *Style, *Changed,
+      tooling::calculateRangesAfterReplacements(IncludeReplaces, {Range}),
+      File));
+}
+
+std::vector<lsTextEdit>
+ReplacementsToEdits(std::string_view code, const tooling::Replacements &Repls) {
+  std::vector<lsTextEdit> ret;
+  int i = 0, line = 0, col = 0;
+  auto move = [&](int p) {
+    for (; i < p; i++)
+      if (code[i] == '\n')
+        line++, col = 0;
+      else {
+        if ((uint8_t)code[i] >= 128) {
+          while (128 <= (uint8_t)code[++i] && (uint8_t)code[i] < 192)
+            ;
+          i--;
+        }
+        col++;
+      }
+  };
+  for (const auto &R : Repls) {
+    move(R.getOffset());
+    int l = line, c = col;
+    move(R.getOffset() + R.getLength());
+    ret.push_back({{{l, c}, {line, col}}, R.getReplacementText().str()});
+  }
+  return ret;
+}
+
+void Format(WorkingFile *wfile, tooling::Range range, lsRequestId id) {
+  std::string_view code = wfile->buffer_content;
+  auto ReplsOrErr =
+      FormatCode(code, wfile->filename, range);
+  if (ReplsOrErr) {
+    Out_TextDocumentFormatting out;
+    out.id = id;
+    out.result = ReplacementsToEdits(code, *ReplsOrErr);
+    pipeline::WriteStdout(formatting, out);
+  } else {
+    Out_Error err;
+    err.id = id;
+    err.error.code = lsErrorCodes::UnknownErrorCode;
+    err.error.message = llvm::toString(ReplsOrErr.takeError());
+    pipeline::WriteStdout(kMethodType_Unknown, err);
+  }
+}
+
+struct In_TextDocumentFormatting : public RequestInMessage {
+  MethodType GetMethodType() const override { return formatting; }
+  struct Params {
+    lsTextDocumentIdentifier textDocument;
+    lsFormattingOptions options;
+  } params;
+};
+MAKE_REFLECT_STRUCT(In_TextDocumentFormatting::Params, textDocument, options);
+MAKE_REFLECT_STRUCT(In_TextDocumentFormatting, id, params);
+REGISTER_IN_MESSAGE(In_TextDocumentFormatting);
+
+struct Handler_TextDocumentFormatting
+    : BaseMessageHandler<In_TextDocumentFormatting> {
+  MethodType GetMethodType() const override { return formatting; }
+  void Run(In_TextDocumentFormatting *request) override {
+    auto &params = request->params;
+    QueryFile *file;
+    if (!FindFileOrFail(db, project, request->id,
+                        params.textDocument.uri.GetPath(), &file))
+      return;
+    WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+    if (!wfile)
+      return;
+    Format(wfile, {0, (unsigned)wfile->buffer_content.size()}, request->id);
+  }
+};
+REGISTER_MESSAGE_HANDLER(Handler_TextDocumentFormatting);
+
+struct In_TextDocumentOnTypeFormatting : public RequestInMessage {
+  MethodType GetMethodType() const override { return onTypeFormatting; }
+  struct Params {
+    lsTextDocumentIdentifier textDocument;
+    lsPosition position;
+    std::string ch;
+    lsFormattingOptions options;
+  } params;
+};
+MAKE_REFLECT_STRUCT(In_TextDocumentOnTypeFormatting::Params, textDocument,
+                    position, ch, options);
+MAKE_REFLECT_STRUCT(In_TextDocumentOnTypeFormatting, id, params);
+REGISTER_IN_MESSAGE(In_TextDocumentOnTypeFormatting);
+
+struct Handler_TextDocumentOnTypeFormatting
+    : BaseMessageHandler<In_TextDocumentOnTypeFormatting> {
+  MethodType GetMethodType() const override { return onTypeFormatting; }
+  void Run(In_TextDocumentOnTypeFormatting *request) override {
+    auto &params = request->params;
+    QueryFile *file;
+    if (!FindFileOrFail(db, project, request->id,
+                        params.textDocument.uri.GetPath(), &file))
+      return;
+    WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+    if (!wfile)
+      return;
+    std::string_view code = wfile->buffer_content;
+    int pos = GetOffsetForPosition(params.position, code);
+    auto lbrace = code.find_last_of('{', pos);
+    if (lbrace == std::string::npos)
+      lbrace = pos;
+    Format(wfile, {(unsigned)lbrace, unsigned(pos - lbrace)}, request->id);
+  }
+};
+REGISTER_MESSAGE_HANDLER(Handler_TextDocumentOnTypeFormatting);
+
+struct In_TextDocumentRangeFormatting : public RequestInMessage {
+  MethodType GetMethodType() const override { return rangeFormatting; }
+  struct Params {
+    lsTextDocumentIdentifier textDocument;
+    lsRange range;
+    lsFormattingOptions options;
+  } params;
+};
+MAKE_REFLECT_STRUCT(In_TextDocumentRangeFormatting::Params, textDocument, range,
+                    options);
+MAKE_REFLECT_STRUCT(In_TextDocumentRangeFormatting, id, params);
+REGISTER_IN_MESSAGE(In_TextDocumentRangeFormatting);
+
+struct Handler_TextDocumentRangeFormatting
+    : BaseMessageHandler<In_TextDocumentRangeFormatting> {
+  MethodType GetMethodType() const override { return rangeFormatting; }
+
+  void Run(In_TextDocumentRangeFormatting *request) override {
+    auto &params = request->params;
+    QueryFile *file;
+    if (!FindFileOrFail(db, project, request->id,
+                        params.textDocument.uri.GetPath(), &file))
+      return;
+    WorkingFile *wfile = working_files->GetFileByFilename(file->def->path);
+    if (!wfile)
+      return;
+    std::string_view code = wfile->buffer_content;
+    int begin = GetOffsetForPosition(params.range.start, code),
+        end = GetOffsetForPosition(params.range.end, code);
+    Format(wfile, {(unsigned)begin, unsigned(end - begin)}, request->id);
+  }
+};
+REGISTER_MESSAGE_HANDLER(Handler_TextDocumentRangeFormatting);
+} // namespace