1 files changed, 116 insertions, 0 deletions
diff --git a/clang-tools-extra/clangd/ProtocolHandlers.cpp b/clang-tools-extra/clangd/ProtocolHandlers.cpp
new file mode 100644
index 00000000000..2fe7b89490b
--- /dev/null
+++ b/clang-tools-extra/clangd/ProtocolHandlers.cpp
@@ -0,0 +1,116 @@
+//===--- ProtocolHandlers.cpp - LSP callbacks -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ProtocolHandlers.h"
+#include "DocumentStore.h"
+#include "clang/Format/Format.h"
+using namespace clang;
+using namespace clangd;
+
+void TextDocumentDidOpenHandler::handleNotification(
+    llvm::yaml::MappingNode *Params) {
+  auto DOTDP = DidOpenTextDocumentParams::parse(Params);
+  if (!DOTDP) {
+    Logs << "Failed to decode DidOpenTextDocumentParams!\n";
+    return;
+  }
+  Store.addDocument(DOTDP->textDocument.uri, DOTDP->textDocument.text);
+}
+
+void TextDocumentDidChangeHandler::handleNotification(
+    llvm::yaml::MappingNode *Params) {
+  auto DCTDP = DidChangeTextDocumentParams::parse(Params);
+  if (!DCTDP || DCTDP->contentChanges.size() != 1) {
+    Logs << "Failed to decode DidChangeTextDocumentParams!\n";
+    return;
+  }
+  // We only support full syncing right now.
+  Store.addDocument(DCTDP->textDocument.uri, DCTDP->contentChanges[0].text);
+}
+
+/// Turn a [line, column] pair into an offset in Code.
+static size_t positionToOffset(StringRef Code, Position P) {
+  size_t Offset = 0;
+  for (int I = 0; I != P.line; ++I) {
+    // FIXME: \r\n
+    // FIXME: UTF-8
+    size_t F = Code.find('\n', Offset);
+    if (F == StringRef::npos)
+      return 0; // FIXME: Is this reasonable?
+    Offset = F + 1;
+  }
+  return (Offset == 0 ? 0 : (Offset - 1)) + P.character;
+}
+
+/// Turn an offset in Code into a [line, column] pair.
+static Position offsetToPosition(StringRef Code, size_t Offset) {
+  StringRef JustBefore = Code.substr(0, Offset);
+  // FIXME: \r\n
+  // FIXME: UTF-8
+  int Lines = JustBefore.count('\n');
+  int Cols = JustBefore.size() - JustBefore.rfind('\n') - 1;
+  return {Lines, Cols};
+}
+
+static std::string formatCode(StringRef Code, StringRef Filename,
+                              ArrayRef<tooling::Range> Ranges, StringRef ID) {
+  // Call clang-format.
+  // FIXME: Don't ignore style.
+  format::FormatStyle Style = format::getLLVMStyle();
+  tooling::Replacements Replacements =
+      format::reformat(Style, Code, Ranges, Filename);
+
+  // Now turn the replacements into the format specified by the Language Server
+  // Protocol. Fuse them into one big JSON array.
+  std::string Edits;
+  for (auto &R : Replacements) {
+    Range ReplacementRange = {
+        offsetToPosition(Code, R.getOffset()),
+        offsetToPosition(Code, R.getOffset() + R.getLength())};
+    TextEdit TE = {ReplacementRange, R.getReplacementText()};
+    Edits += TextEdit::unparse(TE);
+    Edits += ',';
+  }
+  if (!Edits.empty())
+    Edits.pop_back();
+
+  return R"({"jsonrpc":"2.0","id":)" + ID.str() +
+         R"(,"result":[)" + Edits + R"(]})";
+}
+
+void TextDocumentRangeFormattingHandler::handleMethod(
+    llvm::yaml::MappingNode *Params, StringRef ID) {
+  auto DRFP = DocumentRangeFormattingParams::parse(Params);
+  if (!DRFP) {
+    Logs << "Failed to decode DocumentRangeFormattingParams!\n";
+    return;
+  }
+
+  StringRef Code = Store.getDocument(DRFP->textDocument.uri);
+
+  size_t Begin = positionToOffset(Code, DRFP->range.start);
+  size_t Len = positionToOffset(Code, DRFP->range.end) - Begin;
+
+  writeMessage(formatCode(Code, DRFP->textDocument.uri,
+                          {clang::tooling::Range(Begin, Len)}, ID));
+}
+
+void TextDocumentFormattingHandler::handleMethod(
+    llvm::yaml::MappingNode *Params, StringRef ID) {
+  auto DFP = DocumentFormattingParams::parse(Params);
+  if (!DFP) {
+    Logs << "Failed to decode DocumentFormattingParams!\n";
+    return;
+  }
+
+  // Format everything.
+  StringRef Code = Store.getDocument(DFP->textDocument.uri);
+  writeMessage(formatCode(Code, DFP->textDocument.uri,
+                          {clang::tooling::Range(0, Code.size())}, ID));
+}