[clang-tidy] Add modernize-use-using

http://reviews.llvm.org/D18919

llvm-svn: 273786

1 files changed, 93 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
new file mode 100644
index 0000000..498a95c
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
@@ -0,0 +1,93 @@
+//===--- UseUsingCheck.cpp - clang-tidy------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "UseUsingCheck.h"
+#include "../utils/LexerUtils.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+void UseUsingCheck::registerMatchers(MatchFinder *Finder) {
+  if (!getLangOpts().CPlusPlus11)
+    return;
+  Finder->addMatcher(typedefDecl().bind("typedef"), this);
+}
+
+// Checks if 'typedef' keyword can be removed - we do it only if
+// it is the only declaration in a declaration chain.
+static bool CheckRemoval(SourceManager &SM, const SourceLocation &LocStart,
+                         const SourceLocation &LocEnd, ASTContext &Context,
+                         SourceRange &ResultRange) {
+  FileID FID = SM.getFileID(LocEnd);
+  llvm::MemoryBuffer *Buffer = SM.getBuffer(FID, LocEnd);
+  Lexer DeclLexer(SM.getLocForStartOfFile(FID), Context.getLangOpts(),
+                  Buffer->getBufferStart(), SM.getCharacterData(LocStart),
+                  Buffer->getBufferEnd());
+  Token DeclToken;
+  bool result = false;
+  int parenthesisLevel = 0;
+
+  while (!DeclLexer.LexFromRawLexer(DeclToken)) {
+    if (DeclToken.getKind() == tok::TokenKind::l_paren)
+      parenthesisLevel++;
+    if (DeclToken.getKind() == tok::TokenKind::r_paren)
+      parenthesisLevel--;
+    if (DeclToken.getKind() == tok::TokenKind::semi)
+      break;
+    // if there is comma and we are not between open parenthesis then it is
+    // two or more declatarions in this chain
+    if (parenthesisLevel == 0 && DeclToken.getKind() == tok::TokenKind::comma)
+      return false;
+
+    if (DeclToken.isOneOf(tok::TokenKind::identifier,
+                          tok::TokenKind::raw_identifier)) {
+      auto TokenStr = DeclToken.getRawIdentifier().str();
+
+      if (TokenStr == "typedef") {
+        ResultRange =
+            SourceRange(DeclToken.getLocation(), DeclToken.getEndLoc());
+        result = true;
+      }
+    }
+  }
+  // assert if there was keyword 'typedef' in declaration
+  assert(result && "No typedef found");
+
+  return result;
+}
+
+void UseUsingCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *MatchedDecl = Result.Nodes.getNodeAs<TypedefDecl>("typedef");
+  if (MatchedDecl->getLocation().isInvalid())
+    return;
+
+  auto &Context = *Result.Context;
+  auto &SM = *Result.SourceManager;
+
+  auto Diag =
+      diag(MatchedDecl->getLocStart(), "use 'using' instead of 'typedef'");
+  if (MatchedDecl->getLocStart().isMacroID()) {
+    return;
+  }
+  SourceRange RemovalRange;
+  if (CheckRemoval(SM, MatchedDecl->getLocStart(), MatchedDecl->getLocEnd(),
+                   Context, RemovalRange)) {
+    Diag << FixItHint::CreateReplacement(
+        MatchedDecl->getSourceRange(),
+        "using " + MatchedDecl->getNameAsString() + " = " +
+            MatchedDecl->getUnderlyingType().getAsString(getLangOpts()));
+  }
+}
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang