[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, 27 insertions, 1 deletions

diff --git a/clang-tools-extra/clangd/SourceCode.h b/clang-tools-extra/clangd/SourceCode.h
index 81b4672b184..53a140fe4ab 100644
--- a/clang-tools-extra/clangd/SourceCode.h
+++ b/clang-tools-extra/clangd/SourceCode.h
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_SOURCECODE_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_SOURCECODE_H
+
 #include "Context.h"
 #include "Protocol.h"
 #include "clang/Basic/Diagnostic.h"
@@ -22,7 +23,9 @@
 #include "clang/Tooling/Core/Replacement.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSet.h"
+#include "llvm/Support/Error.h"
 #include "llvm/Support/SHA1.h"
+#include <string>
 
 namespace clang {
 class SourceManager;
@@ -197,11 +200,34 @@ format::FormatStyle getFormatStyleForFile(llvm::StringRef File,
                                           llvm::StringRef Content,
                                           llvm::vfs::FileSystem *FS);
 
-// Cleanup and format the given replacements.
+/// Cleanup and format the given replacements.
 llvm::Expected<tooling::Replacements>
 cleanupAndFormat(StringRef Code, const tooling::Replacements &Replaces,
                  const format::FormatStyle &Style);
 
+/// A set of edits generated for a single file. Can verify whether it is safe to
+/// apply these edits to a code block.
+struct Edit {
+  tooling::Replacements Replacements;
+  std::string InitialCode;
+
+  Edit(llvm::StringRef Code, tooling::Replacements Reps)
+      : Replacements(std::move(Reps)), InitialCode(Code) {}
+
+  /// Returns the file contents after changes are applied.
+  llvm::Expected<std::string> apply() const;
+
+  /// Represents Replacements as TextEdits that are available for use in LSP.
+  std::vector<TextEdit> asTextEdits() const;
+
+  /// Checks whether the Replacements are applicable to given Code.
+  bool canApplyTo(llvm::StringRef Code) const;
+};
+
+/// Formats the edits and code around it according to Style. Changes
+/// Replacements to formatted ones if succeeds.
+llvm::Error reformatEdit(Edit &E, const format::FormatStyle &Style);
+
 /// Collects identifiers with counts in the source code.
 llvm::StringMap<unsigned> collectIdentifiers(llvm::StringRef Content,
                                              const format::FormatStyle &Style);