clang-tools-extra/clangd/refactor/tweaks/RawStringLiteral.cpp

   1 //===--- RawStringLiteral.cpp ------------------------------------*- C++-*-===//
   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 #include "ParsedAST.h"
   9 #include "refactor/Tweak.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/AST/Stmt.h"
  12 #include "clang/Basic/LangOptions.h"
  13 #include "clang/Basic/SourceLocation.h"
  14 #include "clang/Basic/SourceManager.h"
  15 #include "clang/Tooling/Core/Replacement.h"
  16 #include "llvm/ADT/StringRef.h"
  17 #include "llvm/Support/Casting.h"
  18 #include "llvm/Support/Error.h"
  19
  20 namespace clang {
  21 namespace clangd {
  22 namespace {
  23 /// Converts a string literal to a raw string.
  24 /// Before:
  25 ///   printf("\"a\"\nb");
  26 ///          ^^^^^^^^^
  27 /// After:
  28 ///   printf(R"("a"
  29 /// b)");
  30 class RawStringLiteral : public Tweak {
  31 public:
  32   const char *id() const final;
  33
  34   bool prepare(const Selection &Inputs) override;
  35   Expected<Effect> apply(const Selection &Inputs) override;
  36   std::string title() const override { return "Convert to raw string"; }
  37   llvm::StringLiteral kind() const override {
  38     return CodeAction::REFACTOR_KIND;
  39   }
  40
  41 private:
  42   const clang::StringLiteral *Str = nullptr;
  43 };
  44
  45 REGISTER_TWEAK(RawStringLiteral)
  46
  47 static bool isFeatureAvailable(const ASTContext &Context) {
  48   // Raw strings are available only for C++11 or later versions, and they are
  49   // not available for C.
  50   return Context.getLangOpts().CPlusPlus11;
  51 }
  52
  53 static bool isNormalString(const StringLiteral &Str, SourceLocation Cursor,
  54                           SourceManager &SM) {
  55   // All chunks must be normal ASCII strings, not u8"..." etc.
  56   if (!Str.isOrdinary())
  57     return false;
  58   SourceLocation LastTokenBeforeCursor;
  59   for (auto I = Str.tokloc_begin(), E = Str.tokloc_end(); I != E; ++I) {
  60     if (I->isMacroID()) // No tokens in the string may be macro expansions.
  61       return false;
  62     if (SM.isBeforeInTranslationUnit(*I, Cursor) || *I == Cursor)
  63       LastTokenBeforeCursor = *I;
  64   }
  65   // Token we care about must be a normal "string": not raw, u8, etc.
  66   const char* Data = SM.getCharacterData(LastTokenBeforeCursor);
  67   return Data && *Data == '"';
  68 }
  69
  70 static bool needsRaw(llvm::StringRef Content) {
  71   return Content.find_first_of("\"\n\t") != StringRef::npos;
  72 }
  73
  74 static bool canBeRaw(llvm::StringRef Content) {
  75   for (char C : Content)
  76     if (!llvm::isPrint(C) && C != '\n' && C != '\t')
  77       return false;
  78   return !Content.contains(")\"");
  79 }
  80
  81 bool RawStringLiteral::prepare(const Selection &Inputs) {
  82   if (!isFeatureAvailable(Inputs.AST->getASTContext())) {
  83     return false;
  84   }
  85   const SelectionTree::Node *N = Inputs.ASTSelection.commonAncestor();
  86   if (!N)
  87     return false;
  88   Str = dyn_cast_or_null<StringLiteral>(N->ASTNode.get<Stmt>());
  89   return Str &&
  90          isNormalString(*Str, Inputs.Cursor, Inputs.AST->getSourceManager()) &&
  91          needsRaw(Str->getBytes()) && canBeRaw(Str->getBytes());
  92 }
  93
  94 Expected<Tweak::Effect> RawStringLiteral::apply(const Selection &Inputs) {
  95   auto &SM = Inputs.AST->getSourceManager();
  96   auto Reps = tooling::Replacements(
  97       tooling::Replacement(SM, Str, ("R\"(" + Str->getBytes() + ")\"").str(),
  98                            Inputs.AST->getLangOpts()));
  99   return Effect::mainFileEdit(SM, std::move(Reps));
 100 }
 101
 102 } // namespace
 103 } // namespace clangd
 104 } // namespace clang