Add replace-auto_ptr check.

Summary: Migrate replace-auto_ptr check from clang-modernize to modernize module in clang-tidy.

Reviewers: alexfh

Subscribers: klimek, cfe-commits

Differential Revision: http://reviews.llvm.org/D12287

llvm-svn: 245933
diff --git a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
index 56ef660..1d575af5 100644
--- a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
@@ -5,6 +5,7 @@
   LoopConvertUtils.cpp
   ModernizeTidyModule.cpp
   PassByValueCheck.cpp
+  ReplaceAutoPtrCheck.cpp
   UseAutoCheck.cpp
   UseNullptrCheck.cpp
 
diff --git a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
index 9f482b1..71c6221 100644
--- a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
@@ -12,6 +12,7 @@
 #include "../ClangTidyModuleRegistry.h"
 #include "LoopConvertCheck.h"
 #include "PassByValueCheck.h"
+#include "ReplaceAutoPtrCheck.h"
 #include "UseAutoCheck.h"
 #include "UseNullptrCheck.h"
 
@@ -26,6 +27,8 @@
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
     CheckFactories.registerCheck<LoopConvertCheck>("modernize-loop-convert");
     CheckFactories.registerCheck<PassByValueCheck>("modernize-pass-by-value");
+    CheckFactories.registerCheck<ReplaceAutoPtrCheck>(
+        "modernize-replace-auto-ptr");
     CheckFactories.registerCheck<UseAutoCheck>("modernize-use-auto");
     CheckFactories.registerCheck<UseNullptrCheck>("modernize-use-nullptr");
   }
@@ -35,6 +38,7 @@
     auto &Opts = Options.CheckOptions;
     Opts["modernize-loop-convert.MinConfidence"] = "reasonable";
     Opts["modernize-pass-by-value.IncludeStyle"] = "llvm"; // Also: "google".
+    Opts["modernize-replace-auto-ptr.IncludeStyle"] = "llvm"; // Also: "google".
 
     // Comma-separated list of macros that behave like NULL.
     Opts["modernize-use-nullptr.NullMacros"] = "NULL";
diff --git a/clang-tools-extra/clang-tidy/modernize/ReplaceAutoPtrCheck.cpp b/clang-tools-extra/clang-tidy/modernize/ReplaceAutoPtrCheck.cpp
new file mode 100644
index 0000000..83f1282
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/ReplaceAutoPtrCheck.cpp
@@ -0,0 +1,262 @@
+//===--- ReplaceAutoPtrCheck.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 "ReplaceAutoPtrCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Lex/Preprocessor.h"
+
+using namespace clang;
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+const char AutoPtrTokenId[] = "AutoPrTokenId";
+const char AutoPtrOwnershipTransferId[] = "AutoPtrOwnershipTransferId";
+
+/// \brief Matches expressions that are lvalues.
+///
+/// In the following example, a[0] matches expr(isLValue()):
+/// \code
+///   std::string a[2];
+///   std::string b;
+///   b = a[0];
+///   b = "this string won't match";
+/// \endcode
+AST_MATCHER(Expr, isLValue) { return Node.getValueKind() == VK_LValue; }
+
+/// Matches declarations whose declaration context is the C++ standard library
+/// namespace std.
+///
+/// Note that inline namespaces are silently ignored during the lookup since
+/// both libstdc++ and libc++ are known to use them for versioning purposes.
+///
+/// Given:
+/// \code
+///   namespace ns {
+///     struct my_type {};
+///     using namespace std;
+///   }
+///
+///   using std::vector;
+///   using ns:my_type;
+///   using ns::list;
+/// \code
+///
+/// usingDecl(hasAnyUsingShadowDecl(hasTargetDecl(isFromStdNamespace())))
+/// matches "using std::vector" and "using ns::list".
+AST_MATCHER(Decl, isFromStdNamespace) {
+  const DeclContext *D = Node.getDeclContext();
+
+  while (D->isInlineNamespace())
+    D = D->getParent();
+
+  if (!D->isNamespace() || !D->getParent()->isTranslationUnit())
+    return false;
+
+  const IdentifierInfo *Info = cast<NamespaceDecl>(D)->getIdentifier();
+
+  return (Info && Info->isStr("std"));
+}
+
+/// \brief Matcher that finds auto_ptr declarations.
+static DeclarationMatcher AutoPtrDecl =
+    recordDecl(hasName("auto_ptr"), isFromStdNamespace());
+
+/// \brief Matches types declared as auto_ptr.
+static TypeMatcher AutoPtrType = qualType(hasDeclaration(AutoPtrDecl));
+
+/// \brief Matcher that finds expressions that are candidates to be wrapped with
+/// 'std::move'.
+///
+/// Binds the id \c AutoPtrOwnershipTransferId to the expression.
+static StatementMatcher MovableArgumentMatcher =
+    expr(allOf(isLValue(), hasType(AutoPtrType)))
+        .bind(AutoPtrOwnershipTransferId);
+
+/// \brief Creates a matcher that finds the locations of types referring to the
+/// \c std::auto_ptr() type.
+///
+/// \code
+///   std::auto_ptr<int> a;
+///        ^~~~~~~~~~~~~
+///
+///   typedef std::auto_ptr<int> int_ptr_t;
+///                ^~~~~~~~~~~~~
+///
+///   std::auto_ptr<int> fn(std::auto_ptr<int>);
+///        ^~~~~~~~~~~~~         ^~~~~~~~~~~~~
+///
+///   <etc...>
+/// \endcode
+TypeLocMatcher makeAutoPtrTypeLocMatcher() {
+  // Skip elaboratedType() as the named type will match soon thereafter.
+  return typeLoc(loc(qualType(AutoPtrType, unless(elaboratedType()))))
+      .bind(AutoPtrTokenId);
+}
+
+/// \brief Creates a matcher that finds the using declarations referring to
+/// \c std::auto_ptr.
+///
+/// \code
+///   using std::auto_ptr;
+///   ^~~~~~~~~~~~~~~~~~~
+/// \endcode
+DeclarationMatcher makeAutoPtrUsingDeclMatcher() {
+  return usingDecl(hasAnyUsingShadowDecl(hasTargetDecl(
+                       allOf(hasName("auto_ptr"), isFromStdNamespace()))))
+      .bind(AutoPtrTokenId);
+}
+
+/// \brief Creates a matcher that finds the \c std::auto_ptr copy-ctor and
+/// assign-operator expressions.
+///
+/// \c AutoPtrOwnershipTransferId is assigned to the argument of the expression,
+/// this is the part that has to be wrapped by \c std::move().
+///
+/// \code
+///   std::auto_ptr<int> i, j;
+///   i = j;
+///   ~~~~^
+/// \endcode
+StatementMatcher makeTransferOwnershipExprMatcher() {
+  return anyOf(operatorCallExpr(allOf(hasOverloadedOperatorName("="),
+                                      callee(methodDecl(ofClass(AutoPtrDecl))),
+                                      hasArgument(1, MovableArgumentMatcher))),
+               constructExpr(allOf(hasType(AutoPtrType), argumentCountIs(1),
+                                   hasArgument(0, MovableArgumentMatcher))));
+}
+
+/// \brief Locates the \c auto_ptr token when it is referred by a \c TypeLoc.
+///
+/// \code
+///   std::auto_ptr<int> i;
+///        ^~~~~~~~~~~~~
+/// \endcode
+///
+/// The caret represents the location returned and the tildes cover the
+/// parameter \p AutoPtrTypeLoc.
+///
+/// \return An invalid \c SourceLocation if not found, otherwise the location
+/// of the beginning of the \c auto_ptr token.
+static SourceLocation locateFromTypeLoc(const TypeLoc *AutoPtrTypeLoc,
+                                        const SourceManager &SM) {
+  auto TL = AutoPtrTypeLoc->getAs<TemplateSpecializationTypeLoc>();
+  if (TL.isNull())
+    return SourceLocation();
+
+  return TL.getTemplateNameLoc();
+}
+
+/// \brief Locates the \c auto_ptr token in using declarations.
+///
+/// \code
+///   using std::auto_ptr;
+///              ^
+/// \endcode
+///
+/// The caret represents the location returned.
+///
+/// \return An invalid \c SourceLocation if not found, otherwise the location
+/// of the beginning of the \c auto_ptr token.
+static SourceLocation locateFromUsingDecl(const UsingDecl *UsingAutoPtrDecl,
+                                          const SourceManager &SM) {
+  return UsingAutoPtrDecl->getNameInfo().getBeginLoc();
+}
+
+/// \brief Verifies that the token at \p TokenStart is 'auto_ptr'.
+static bool checkTokenIsAutoPtr(SourceLocation TokenStart,
+                                const SourceManager &SM,
+                                const LangOptions &LO) {
+  SmallVector<char, 8> Buffer;
+  bool Invalid = false;
+  StringRef Res = Lexer::getSpelling(TokenStart, Buffer, SM, LO, &Invalid);
+
+  return (!Invalid && Res == "auto_ptr");
+}
+
+ReplaceAutoPtrCheck::ReplaceAutoPtrCheck(StringRef Name,
+                                         ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      IncludeStyle(Options.get("IncludeStyle", "llvm") == "llvm"
+                       ? IncludeSorter::IS_LLVM
+                       : IncludeSorter::IS_Google) {}
+
+void ReplaceAutoPtrCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "IncludeStyle",
+                IncludeStyle == IncludeSorter::IS_LLVM ? "llvm" : "google");
+}
+
+void ReplaceAutoPtrCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(makeAutoPtrTypeLocMatcher(), this);
+  Finder->addMatcher(makeAutoPtrUsingDeclMatcher(), this);
+  Finder->addMatcher(makeTransferOwnershipExprMatcher(), this);
+}
+
+void ReplaceAutoPtrCheck::registerPPCallbacks(CompilerInstance &Compiler) {
+  Inserter.reset(new IncludeInserter(Compiler.getSourceManager(),
+                                     Compiler.getLangOpts(), IncludeStyle));
+  Compiler.getPreprocessor().addPPCallbacks(Inserter->CreatePPCallbacks());
+}
+
+void ReplaceAutoPtrCheck::check(const MatchFinder::MatchResult &Result) {
+  SourceManager &SM = *Result.SourceManager;
+  if (const auto *E =
+          Result.Nodes.getNodeAs<Expr>(AutoPtrOwnershipTransferId)) {
+    CharSourceRange Range = Lexer::makeFileCharRange(
+        CharSourceRange::getTokenRange(E->getSourceRange()), SM, LangOptions());
+
+    if (Range.isInvalid())
+      return;
+
+    auto Diag = diag(Range.getBegin(), "use std::move to transfer ownership")
+                << FixItHint::CreateInsertion(Range.getBegin(), "std::move(")
+                << FixItHint::CreateInsertion(Range.getEnd(), ")");
+
+    auto Insertion =
+        Inserter->CreateIncludeInsertion(SM.getMainFileID(), "utility",
+                                         /*IsAngled=*/true);
+    if (Insertion.hasValue())
+      Diag << Insertion.getValue();
+
+    return;
+  }
+
+  SourceLocation IdentifierLoc;
+  if (const auto *TL = Result.Nodes.getNodeAs<TypeLoc>(AutoPtrTokenId)) {
+    IdentifierLoc = locateFromTypeLoc(TL, SM);
+  } else if (const auto *D =
+                 Result.Nodes.getNodeAs<UsingDecl>(AutoPtrTokenId)) {
+    IdentifierLoc = locateFromUsingDecl(D, SM);
+  } else {
+    llvm_unreachable("Bad Callback. No node provided.");
+  }
+
+  if (IdentifierLoc.isMacroID())
+    IdentifierLoc = SM.getSpellingLoc(IdentifierLoc);
+
+  // Ensure that only the 'auto_ptr' token is replaced and not the template
+  // aliases.
+  if (!checkTokenIsAutoPtr(IdentifierLoc, SM, LangOptions()))
+    return;
+
+  SourceLocation EndLoc =
+      IdentifierLoc.getLocWithOffset(strlen("auto_ptr") - 1);
+  diag(IdentifierLoc, "auto_ptr is deprecated, use unique_ptr instead")
+      << FixItHint::CreateReplacement(SourceRange(IdentifierLoc, EndLoc),
+                                      "unique_ptr");
+}
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
diff --git a/clang-tools-extra/clang-tidy/modernize/ReplaceAutoPtrCheck.h b/clang-tools-extra/clang-tidy/modernize/ReplaceAutoPtrCheck.h
new file mode 100644
index 0000000..4aad852
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/ReplaceAutoPtrCheck.h
@@ -0,0 +1,59 @@
+//===--- ReplaceAutoPtrCheck.h - clang-tidy----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_REPLACE_AUTO_PTR_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_REPLACE_AUTO_PTR_H
+
+#include "../ClangTidy.h"
+#include "../utils/IncludeInserter.h"
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+/// \brief Transforms the deprecated \c std::auto_ptr into the C++11 \c
+/// std::unique_ptr.
+///
+/// Note that both the \c std::auto_ptr type and the transfer of ownership are
+/// transformed. \c std::auto_ptr provides two ways to transfer the ownership,
+/// the copy-constructor and the assignment operator. Unlike most classes these
+/// operations do not 'copy' the resource but they 'steal' it.
+/// \c std::unique_ptr uses move semantics instead, which makes the intent of
+/// transferring the resource explicit. This difference between the two smart
+/// pointers requeres to wrap the copy-ctor and assign-operator with
+/// \c std::move().
+///
+/// For example, given:
+/// \code
+///   std::auto_ptr<int> i, j;
+///   i = j;
+/// \endcode
+/// This code is transformed to:
+/// \code
+///   std::unique_ptr<in> i, j;
+///   i = std::move(j);
+/// \endcode
+class ReplaceAutoPtrCheck : public ClangTidyCheck {
+public:
+  ReplaceAutoPtrCheck(StringRef Name, ClangTidyContext *Context);
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void registerPPCallbacks(CompilerInstance &Compiler) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
+  std::unique_ptr<IncludeInserter> Inserter;
+  const IncludeSorter::IncludeStyle IncludeStyle;
+};
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_REPLACE_AUTO_PTR_H