[clangd] Support multifile edits as output of Tweaks

Summary:
First patch for propogating multifile changes from tweak outputs to LSP
WorkspaceEdits.

Uses SM to convert tooling::Replacements to TextEdits.
Errors out if there are any inconsistencies between the draft version and the
version generated the edits.

Reviewers: sammccall

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66637

llvm-svn: 371392

1 files changed, 61 insertions, 1 deletions

diff --git a/clang-tools-extra/clangd/SourceCode.cpp b/clang-tools-extra/clangd/SourceCode.cpp
index 812e42a7a2a..95f250c9d6a 100644
--- a/clang-tools-extra/clangd/SourceCode.cpp
+++ b/clang-tools-extra/clangd/SourceCode.cpp
@@ -11,6 +11,7 @@
 #include "FuzzyMatch.h"
 #include "Logger.h"
 #include "Protocol.h"
+#include "refactor/Tweak.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/SourceLocation.h"
@@ -19,14 +20,21 @@
 #include "clang/Format/Format.h"
 #include "clang/Lex/Lexer.h"
 #include "clang/Lex/Preprocessor.h"
+#include "clang/Tooling/Core/Replacement.h"
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/None.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/LineIterator.h"
+#include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/SHA1.h"
+#include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/xxhash.h"
 #include <algorithm>
 
@@ -562,7 +570,7 @@ llvm::Optional<std::string> getCanonicalPath(const FileEntry *F,
   }
 
   // Handle the symbolic link path case where the current working directory
-  // (getCurrentWorkingDirectory) is a symlink./ We always want to the real
+  // (getCurrentWorkingDirectory) is a symlink. We always want to the real
   // file path (instead of the symlink path) for the  C++ symbols.
   //
   // Consider the following example:
@@ -908,5 +916,57 @@ llvm::Optional<DefinedMacro> locateMacroAt(SourceLocation Loc,
   return None;
 }
 
+llvm::Expected<std::string> Edit::apply() const {
+  return tooling::applyAllReplacements(InitialCode, Replacements);
+}
+
+std::vector<TextEdit> Edit::asTextEdits() const {
+  return replacementsToEdits(InitialCode, Replacements);
+}
+
+bool Edit::canApplyTo(llvm::StringRef Code) const {
+  // Create line iterators, since line numbers are important while applying our
+  // edit we cannot skip blank lines.
+  auto LHS = llvm::MemoryBuffer::getMemBuffer(Code);
+  llvm::line_iterator LHSIt(*LHS, /*SkipBlanks=*/false);
+
+  auto RHS = llvm::MemoryBuffer::getMemBuffer(InitialCode);
+  llvm::line_iterator RHSIt(*RHS, /*SkipBlanks=*/false);
+
+  // Compare the InitialCode we prepared the edit for with the Code we received
+  // line by line to make sure there are no differences.
+  // FIXME: This check is too conservative now, it should be enough to only
+  // check lines around the replacements contained inside the Edit.
+  while (!LHSIt.is_at_eof() && !RHSIt.is_at_eof()) {
+    if (*LHSIt != *RHSIt)
+      return false;
+    ++LHSIt;
+    ++RHSIt;
+  }
+
+  // After we reach EOF for any of the files we make sure the other one doesn't
+  // contain any additional content except empty lines, they should not
+  // interfere with the edit we produced.
+  while (!LHSIt.is_at_eof()) {
+    if (!LHSIt->empty())
+      return false;
+    ++LHSIt;
+  }
+  while (!RHSIt.is_at_eof()) {
+    if (!RHSIt->empty())
+      return false;
+    ++RHSIt;
+  }
+  return true;
+}
+
+llvm::Error reformatEdit(Edit &E, const format::FormatStyle &Style) {
+  if (auto NewEdits = cleanupAndFormat(E.InitialCode, E.Replacements, Style))
+    E.Replacements = std::move(*NewEdits);
+  else
+    return NewEdits.takeError();
+  return llvm::Error::success();
+}
+
 } // namespace clangd
 } // namespace clang