[clang-tools-extra] r245434 - [clang-tidy] Add use-nullptr check to clang-tidy.

Alexander Kornienko via cfe-commits cfe-commits at lists.llvm.org
Wed Aug 19 06:13:13 PDT 2015


Author: alexfh
Date: Wed Aug 19 08:13:12 2015
New Revision: 245434

URL: http://llvm.org/viewvc/llvm-project?rev=245434&view=rev
Log:
[clang-tidy] Add use-nullptr check to clang-tidy.

Move UseNullptr from clang-modernize to modernize module in clang-tidy.

http://reviews.llvm.org/D12081

Patch by Angel Garcia!

Added:
    clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.cpp
    clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.h
    clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr-basic.cpp
    clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr.cpp
Modified:
    clang-tools-extra/trunk/clang-tidy/modernize/CMakeLists.txt
    clang-tools-extra/trunk/clang-tidy/modernize/ModernizeTidyModule.cpp

Modified: clang-tools-extra/trunk/clang-tidy/modernize/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/CMakeLists.txt?rev=245434&r1=245433&r2=245434&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/CMakeLists.txt (original)
+++ clang-tools-extra/trunk/clang-tidy/modernize/CMakeLists.txt Wed Aug 19 08:13:12 2015
@@ -5,6 +5,7 @@ add_clang_library(clangTidyModernizeModu
   LoopConvertUtils.cpp
   ModernizeTidyModule.cpp
   PassByValueCheck.cpp
+  UseNullptrCheck.cpp
 
   LINK_LIBS
   clangAST

Modified: clang-tools-extra/trunk/clang-tidy/modernize/ModernizeTidyModule.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/ModernizeTidyModule.cpp?rev=245434&r1=245433&r2=245434&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/ModernizeTidyModule.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/modernize/ModernizeTidyModule.cpp Wed Aug 19 08:13:12 2015
@@ -12,6 +12,7 @@
 #include "../ClangTidyModuleRegistry.h"
 #include "LoopConvertCheck.h"
 #include "PassByValueCheck.h"
+#include "UseNullptrCheck.h"
 
 using namespace clang::ast_matchers;
 
@@ -24,6 +25,7 @@ public:
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
     CheckFactories.registerCheck<LoopConvertCheck>("modernize-loop-convert");
     CheckFactories.registerCheck<PassByValueCheck>("modernize-pass-by-value");
+    CheckFactories.registerCheck<UseNullptrCheck>("modernize-use-nullptr");
   }
 
   ClangTidyOptions getModuleOptions() override {
@@ -31,6 +33,9 @@ public:
     auto &Opts = Options.CheckOptions;
     Opts["modernize-loop-convert.MinConfidence"] = "reasonable";
     Opts["modernize-pass-by-value.IncludeStyle"] = "llvm"; // Also: "google".
+
+    // Comma-separated list of user-defined macros that behave like NULL.
+    Opts["modernize-use-nullptr.UserNullMacros"] = "";
     return Options;
   }
 };

Added: clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.cpp?rev=245434&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.cpp (added)
+++ clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.cpp Wed Aug 19 08:13:12 2015
@@ -0,0 +1,472 @@
+//===--- UseNullptrCheck.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 "UseNullptrCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang;
+using namespace clang::ast_matchers;
+using namespace llvm;
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+const char CastSequence[] = "sequence";
+const char NullMacroName[] = "NULL";
+
+/// \brief Matches cast expressions that have a cast kind of CK_NullToPointer
+/// or CK_NullToMemberPointer.
+///
+/// Given
+/// \code
+///   int *p = 0;
+/// \endcode
+/// implicitCastExpr(isNullToPointer()) matches the implicit cast clang adds
+/// around \c 0.
+AST_MATCHER(CastExpr, isNullToPointer) {
+  return Node.getCastKind() == CK_NullToPointer ||
+         Node.getCastKind() == CK_NullToMemberPointer;
+}
+
+AST_MATCHER(Type, sugaredNullptrType) {
+  const Type *DesugaredType = Node.getUnqualifiedDesugaredType();
+  if (const BuiltinType *BT = dyn_cast<BuiltinType>(DesugaredType))
+    return BT->getKind() == BuiltinType::NullPtr;
+  return false;
+}
+
+/// \brief Create a matcher that finds implicit casts as well as the head of a
+/// sequence of zero or more nested explicit casts that have an implicit cast
+/// to null within.
+/// Finding sequences of explict casts is necessary so that an entire sequence
+/// can be replaced instead of just the inner-most implicit cast.
+StatementMatcher makeCastSequenceMatcher() {
+  StatementMatcher ImplicitCastToNull = implicitCastExpr(
+      isNullToPointer(),
+      unless(hasSourceExpression(hasType(sugaredNullptrType()))));
+
+  return castExpr(anyOf(ImplicitCastToNull,
+                        explicitCastExpr(hasDescendant(ImplicitCastToNull))),
+                  unless(hasAncestor(explicitCastExpr())))
+      .bind(CastSequence);
+}
+
+bool isReplaceableRange(SourceLocation StartLoc, SourceLocation EndLoc,
+                        const SourceManager &SM) {
+  return SM.isWrittenInSameFile(StartLoc, EndLoc);
+}
+
+/// \brief Replaces the provided range with the text "nullptr", but only if
+/// the start and end location are both in main file.
+/// Returns true if and only if a replacement was made.
+void replaceWithNullptr(ClangTidyCheck &Check, SourceManager &SM,
+                        SourceLocation StartLoc, SourceLocation EndLoc) {
+  CharSourceRange Range(SourceRange(StartLoc, EndLoc), true);
+  // Add a space if nullptr follows an alphanumeric character. This happens
+  // whenever there is an c-style explicit cast to nullptr not surrounded by
+  // parentheses and right beside a return statement.
+  SourceLocation PreviousLocation = StartLoc.getLocWithOffset(-1);
+  bool NeedsSpace = isAlphanumeric(*SM.getCharacterData(PreviousLocation));
+  Check.diag(Range.getBegin(), "use nullptr") << FixItHint::CreateReplacement(
+      Range, NeedsSpace ? " nullptr" : "nullptr");
+}
+
+/// \brief Returns the name of the outermost macro.
+///
+/// Given
+/// \code
+/// #define MY_NULL NULL
+/// \endcode
+/// If \p Loc points to NULL, this function will return the name MY_NULL.
+StringRef getOutermostMacroName(SourceLocation Loc, const SourceManager &SM,
+                                const LangOptions &LO) {
+  assert(Loc.isMacroID());
+  SourceLocation OutermostMacroLoc;
+
+  while (Loc.isMacroID()) {
+    OutermostMacroLoc = Loc;
+    Loc = SM.getImmediateMacroCallerLoc(Loc);
+  }
+
+  return Lexer::getImmediateMacroName(OutermostMacroLoc, SM, LO);
+}
+
+/// \brief RecursiveASTVisitor for ensuring all nodes rooted at a given AST
+/// subtree that have file-level source locations corresponding to a macro
+/// argument have implicit NullTo(Member)Pointer nodes as ancestors.
+class MacroArgUsageVisitor : public RecursiveASTVisitor<MacroArgUsageVisitor> {
+public:
+  MacroArgUsageVisitor(SourceLocation CastLoc, const SourceManager &SM)
+      : CastLoc(CastLoc), SM(SM), Visited(false), CastFound(false),
+        InvalidFound(false) {
+    assert(CastLoc.isFileID());
+  }
+
+  bool TraverseStmt(Stmt *S) {
+    bool VisitedPreviously = Visited;
+
+    if (!RecursiveASTVisitor<MacroArgUsageVisitor>::TraverseStmt(S))
+      return false;
+
+    // The point at which VisitedPreviously is false and Visited is true is the
+    // root of a subtree containing nodes whose locations match CastLoc. It's
+    // at this point we test that the Implicit NullTo(Member)Pointer cast was
+    // found or not.
+    if (!VisitedPreviously) {
+      if (Visited && !CastFound) {
+        // Found nodes with matching SourceLocations but didn't come across a
+        // cast. This is an invalid macro arg use. Can stop traversal
+        // completely now.
+        InvalidFound = true;
+        return false;
+      }
+      // Reset state as we unwind back up the tree.
+      CastFound = false;
+      Visited = false;
+    }
+    return true;
+  }
+
+  bool VisitStmt(Stmt *S) {
+    if (SM.getFileLoc(S->getLocStart()) != CastLoc)
+      return true;
+    Visited = true;
+
+    const ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(S);
+    if (Cast && (Cast->getCastKind() == CK_NullToPointer ||
+                 Cast->getCastKind() == CK_NullToMemberPointer))
+      CastFound = true;
+
+    return true;
+  }
+
+  bool foundInvalid() const { return InvalidFound; }
+
+private:
+  SourceLocation CastLoc;
+  const SourceManager &SM;
+
+  bool Visited;
+  bool CastFound;
+  bool InvalidFound;
+};
+
+/// \brief Looks for implicit casts as well as sequences of 0 or more explicit
+/// casts with an implicit null-to-pointer cast within.
+///
+/// The matcher this visitor is used with will find a single implicit cast or a
+/// top-most explicit cast (i.e. it has no explicit casts as an ancestor) where
+/// an implicit cast is nested within. However, there is no guarantee that only
+/// explicit casts exist between the found top-most explicit cast and the
+/// possibly more than one nested implicit cast. This visitor finds all cast
+/// sequences with an implicit cast to null within and creates a replacement
+/// leaving the outermost explicit cast unchanged to avoid introducing
+/// ambiguities.
+class CastSequenceVisitor : public RecursiveASTVisitor<CastSequenceVisitor> {
+public:
+  CastSequenceVisitor(ASTContext &Context,
+                      SmallVector<StringRef, 1> UserNullMacros,
+                      ClangTidyCheck &check)
+      : SM(Context.getSourceManager()), Context(Context),
+        UserNullMacros(std::move(UserNullMacros)), Check(check),
+        FirstSubExpr(nullptr), PruneSubtree(false) {}
+
+  bool TraverseStmt(Stmt *S) {
+    // Stop traversing down the tree if requested.
+    if (PruneSubtree) {
+      PruneSubtree = false;
+      return true;
+    }
+    return RecursiveASTVisitor<CastSequenceVisitor>::TraverseStmt(S);
+  }
+
+  // Only VisitStmt is overridden as we shouldn't find other base AST types
+  // within a cast expression.
+  bool VisitStmt(Stmt *S) {
+    CastExpr *C = dyn_cast<CastExpr>(S);
+    if (!C) {
+      FirstSubExpr = nullptr;
+      return true;
+    }
+    if (!FirstSubExpr)
+      FirstSubExpr = C->getSubExpr()->IgnoreParens();
+
+    if (C->getCastKind() != CK_NullToPointer &&
+        C->getCastKind() != CK_NullToMemberPointer) {
+      return true;
+    }
+
+    SourceLocation StartLoc = FirstSubExpr->getLocStart();
+    SourceLocation EndLoc = FirstSubExpr->getLocEnd();
+
+    // If the location comes from a macro arg expansion, *all* uses of that
+    // arg must be checked to result in NullTo(Member)Pointer casts.
+    //
+    // If the location comes from a macro body expansion, check to see if its
+    // coming from one of the allowed 'NULL' macros.
+    if (SM.isMacroArgExpansion(StartLoc) && SM.isMacroArgExpansion(EndLoc)) {
+      SourceLocation FileLocStart = SM.getFileLoc(StartLoc),
+                     FileLocEnd = SM.getFileLoc(EndLoc);
+      if (isReplaceableRange(FileLocStart, FileLocEnd, SM) &&
+          allArgUsesValid(C)) {
+        replaceWithNullptr(Check, SM, FileLocStart, FileLocEnd);
+      }
+      return skipSubTree();
+    }
+
+    if (SM.isMacroBodyExpansion(StartLoc) && SM.isMacroBodyExpansion(EndLoc)) {
+      StringRef OutermostMacroName =
+          getOutermostMacroName(StartLoc, SM, Context.getLangOpts());
+
+      // Check to see if the user wants to replace the macro being expanded.
+      if (std::find(UserNullMacros.begin(), UserNullMacros.end(),
+                    OutermostMacroName) == UserNullMacros.end()) {
+        return skipSubTree();
+      }
+
+      StartLoc = SM.getFileLoc(StartLoc);
+      EndLoc = SM.getFileLoc(EndLoc);
+    }
+
+    if (!isReplaceableRange(StartLoc, EndLoc, SM)) {
+      return skipSubTree();
+    }
+    replaceWithNullptr(Check, SM, StartLoc, EndLoc);
+
+    return skipSubTree();
+  }
+
+private:
+  bool skipSubTree() {
+    PruneSubtree = true;
+    return true;
+  }
+
+  /// \brief Tests that all expansions of a macro arg, one of which expands to
+  /// result in \p CE, yield NullTo(Member)Pointer casts.
+  bool allArgUsesValid(const CastExpr *CE) {
+    SourceLocation CastLoc = CE->getLocStart();
+
+    // Step 1: Get location of macro arg and location of the macro the arg was
+    // provided to.
+    SourceLocation ArgLoc, MacroLoc;
+    if (!getMacroAndArgLocations(CastLoc, ArgLoc, MacroLoc))
+      return false;
+
+    // Step 2: Find the first ancestor that doesn't expand from this macro.
+    ast_type_traits::DynTypedNode ContainingAncestor;
+    if (!findContainingAncestor(
+            ast_type_traits::DynTypedNode::create<Stmt>(*CE), MacroLoc,
+            ContainingAncestor))
+      return false;
+
+    // Step 3:
+    // Visit children of this containing parent looking for the least-descended
+    // nodes of the containing parent which are macro arg expansions that expand
+    // from the given arg location.
+    // Visitor needs: arg loc
+    MacroArgUsageVisitor ArgUsageVisitor(SM.getFileLoc(CastLoc), SM);
+    if (const auto *D = ContainingAncestor.get<Decl>())
+      ArgUsageVisitor.TraverseDecl(const_cast<Decl *>(D));
+    else if (const auto *S = ContainingAncestor.get<Stmt>())
+      ArgUsageVisitor.TraverseStmt(const_cast<Stmt *>(S));
+    else
+      llvm_unreachable("Unhandled ContainingAncestor node type");
+
+    return !ArgUsageVisitor.foundInvalid();
+  }
+
+  /// \brief Given the SourceLocation for a macro arg expansion, finds the
+  /// non-macro SourceLocation of the macro the arg was passed to and the
+  /// non-macro SourceLocation of the argument in the arg list to that macro.
+  /// These results are returned via \c MacroLoc and \c ArgLoc respectively.
+  /// These values are undefined if the return value is false.
+  ///
+  /// \returns false if one of the returned SourceLocations would be a
+  /// SourceLocation pointing within the definition of another macro.
+  bool getMacroAndArgLocations(SourceLocation Loc, SourceLocation &ArgLoc,
+                               SourceLocation &MacroLoc) {
+    assert(Loc.isMacroID() && "Only reasonble to call this on macros");
+
+    ArgLoc = Loc;
+
+    // Find the location of the immediate macro expansion.
+    while (true) {
+      std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(ArgLoc);
+      const SrcMgr::SLocEntry *E = &SM.getSLocEntry(LocInfo.first);
+      const SrcMgr::ExpansionInfo &Expansion = E->getExpansion();
+
+      SourceLocation OldArgLoc = ArgLoc;
+      ArgLoc = Expansion.getExpansionLocStart();
+      if (!Expansion.isMacroArgExpansion()) {
+        if (!MacroLoc.isFileID())
+          return false;
+
+        StringRef Name =
+            Lexer::getImmediateMacroName(OldArgLoc, SM, Context.getLangOpts());
+        return std::find(UserNullMacros.begin(), UserNullMacros.end(), Name) !=
+               UserNullMacros.end();
+      }
+
+      MacroLoc = SM.getImmediateExpansionRange(ArgLoc).first;
+
+      ArgLoc = Expansion.getSpellingLoc().getLocWithOffset(LocInfo.second);
+      if (ArgLoc.isFileID())
+        return true;
+
+      // If spelling location resides in the same FileID as macro expansion
+      // location, it means there is no inner macro.
+      FileID MacroFID = SM.getFileID(MacroLoc);
+      if (SM.isInFileID(ArgLoc, MacroFID)) {
+        // Don't transform this case. If the characters that caused the
+        // null-conversion come from within a macro, they can't be changed.
+        return false;
+      }
+    }
+
+    llvm_unreachable("getMacroAndArgLocations");
+  }
+
+  /// \brief Tests if TestMacroLoc is found while recursively unravelling
+  /// expansions starting at TestLoc. TestMacroLoc.isFileID() must be true.
+  /// Implementation is very similar to getMacroAndArgLocations() except in this
+  /// case, it's not assumed that TestLoc is expanded from a macro argument.
+  /// While unravelling expansions macro arguments are handled as with
+  /// getMacroAndArgLocations() but in this function macro body expansions are
+  /// also handled.
+  ///
+  /// False means either:
+  /// - TestLoc is not from a macro expansion
+  /// - TestLoc is from a different macro expansion
+  bool expandsFrom(SourceLocation TestLoc, SourceLocation TestMacroLoc) {
+    if (TestLoc.isFileID()) {
+      return false;
+    }
+
+    SourceLocation Loc = TestLoc, MacroLoc;
+
+    while (true) {
+      std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
+      const SrcMgr::SLocEntry *E = &SM.getSLocEntry(LocInfo.first);
+      const SrcMgr::ExpansionInfo &Expansion = E->getExpansion();
+
+      Loc = Expansion.getExpansionLocStart();
+
+      if (!Expansion.isMacroArgExpansion()) {
+        if (Loc.isFileID()) {
+          return Loc == TestMacroLoc;
+        }
+        // Since Loc is still a macro ID and it's not an argument expansion, we
+        // don't need to do the work of handling an argument expansion. Simply
+        // keep recursively expanding until we hit a FileID or a macro arg
+        // expansion or a macro arg expansion.
+        continue;
+      }
+
+      MacroLoc = SM.getImmediateExpansionRange(Loc).first;
+      if (MacroLoc.isFileID() && MacroLoc == TestMacroLoc) {
+        // Match made.
+        return true;
+      }
+
+      Loc = Expansion.getSpellingLoc().getLocWithOffset(LocInfo.second);
+      if (Loc.isFileID()) {
+        // If we made it this far without finding a match, there is no match to
+        // be made.
+        return false;
+      }
+    }
+
+    llvm_unreachable("expandsFrom");
+  }
+
+  /// \brief Given a starting point \c Start in the AST, find an ancestor that
+  /// doesn't expand from the macro called at file location \c MacroLoc.
+  ///
+  /// \pre MacroLoc.isFileID()
+  /// \returns true if such an ancestor was found, false otherwise.
+  bool findContainingAncestor(ast_type_traits::DynTypedNode Start,
+                              SourceLocation MacroLoc,
+                              ast_type_traits::DynTypedNode &Result) {
+    // Below we're only following the first parent back up the AST. This should
+    // be fine since for the statements we care about there should only be one
+    // parent as far up as we care. If this assumption doesn't hold, need to
+    // revisit what to do here.
+
+    assert(MacroLoc.isFileID());
+
+    while (true) {
+      const auto &Parents = Context.getParents(Start);
+      if (Parents.empty())
+        return false;
+      assert(Parents.size() == 1 &&
+             "Found an ancestor with more than one parent!");
+
+      const ast_type_traits::DynTypedNode &Parent = Parents[0];
+
+      SourceLocation Loc;
+      if (const auto *D = Parent.get<Decl>())
+        Loc = D->getLocStart();
+      else if (const auto *S = Parent.get<Stmt>())
+        Loc = S->getLocStart();
+      else
+        llvm_unreachable("Expected to find Decl or Stmt containing ancestor");
+
+      if (!expandsFrom(Loc, MacroLoc)) {
+        Result = Parent;
+        return true;
+      }
+      Start = Parent;
+    }
+
+    llvm_unreachable("findContainingAncestor");
+  }
+
+private:
+  SourceManager &SM;
+  ASTContext &Context;
+  const SmallVector<StringRef, 1> &UserNullMacros;
+  ClangTidyCheck &Check;
+  Expr *FirstSubExpr;
+  bool PruneSubtree;
+};
+
+UseNullptrCheck::UseNullptrCheck(StringRef Name, ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context) {
+  StringRef UserMacrosStr = Options.get("UserNullMacros", "");
+  UserMacrosStr.split(UserNullMacros, ",");
+  UserNullMacros.push_back(StringRef(NullMacroName));
+}
+
+void UseNullptrCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "UserNullMacros", "");
+}
+
+void UseNullptrCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(makeCastSequenceMatcher(), this);
+}
+
+void UseNullptrCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *NullCast = Result.Nodes.getNodeAs<CastExpr>(CastSequence);
+  assert(NullCast && "Bad Callback. No node provided");
+
+  // Given an implicit null-ptr cast or an explicit cast with an implicit
+  // null-to-pointer cast within use CastSequenceVisitor to identify sequences
+  // of explicit casts that can be converted into 'nullptr'.
+  CastSequenceVisitor(*Result.Context, UserNullMacros, *this)
+      .TraverseStmt(const_cast<CastExpr *>(NullCast));
+}
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang

Added: clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.h
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.h?rev=245434&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.h (added)
+++ clang-tools-extra/trunk/clang-tidy/modernize/UseNullptrCheck.h Wed Aug 19 08:13:12 2015
@@ -0,0 +1,34 @@
+//===--- UseNullptrCheck.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_USE_NULLPTR_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USE_NULLPTR_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+class UseNullptrCheck : public ClangTidyCheck {
+public:
+  UseNullptrCheck(StringRef Name, ClangTidyContext *Context);
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
+  SmallVector<StringRef, 1> UserNullMacros;
+};
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USE_NULLPTR_H

Added: clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr-basic.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr-basic.cpp?rev=245434&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr-basic.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr-basic.cpp Wed Aug 19 08:13:12 2015
@@ -0,0 +1,344 @@
+// RUN: $(dirname %s)/check_clang_tidy.sh %s modernize-use-nullptr %t -- \
+// RUN:   -std=c++98 -Wno-non-literal-null-conversion
+// REQUIRES: shell
+
+const unsigned int g_null = 0;
+#define NULL 0
+
+void test_assignment() {
+  int *p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr [modernize-use-nullptr]
+  // CHECK-FIXES: int *p1 = nullptr;
+  p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use nullptr
+  // CHECK-FIXES: p1 = nullptr;
+
+  int *p2 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+  // CHECK-FIXES: int *p2 = nullptr;
+
+  p2 = p1;
+  // CHECK-FIXES: p2 = p1;
+
+  const int null = 0;
+  int *p3 = null;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+  // CHECK-FIXES: int *p3 = nullptr;
+
+  p3 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use nullptr
+  // CHECK-FIXES: p3 = nullptr;
+
+  int *p4 = p3;
+  // CHECK-FIXES: int *p4 = p3;
+
+  p4 = null;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use nullptr
+  // CHECK-FIXES: p4 = nullptr;
+
+  int i1 = 0;
+
+  int i2 = NULL;
+
+  int i3 = null;
+
+  int *p5, *p6, *p7;
+  p5 = p6 = p7 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: use nullptr
+  // CHECK-FIXES: p5 = p6 = p7 = nullptr;
+}
+
+struct Foo {
+  Foo(int *p = NULL) : m_p1(p) {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use nullptr
+  // CHECK-FIXES: Foo(int *p = nullptr) : m_p1(p) {}
+
+  void bar(int *p = 0) {}
+  // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: use nullptr
+  // CHECK-FIXES: void bar(int *p = nullptr) {}
+
+  void baz(int i = 0) {}
+
+  int *m_p1;
+  static int *m_p2;
+};
+
+int *Foo::m_p2 = NULL;
+// CHECK-MESSAGES: :[[@LINE-1]]:18: warning: use nullptr
+// CHECK-FIXES: int *Foo::m_p2 = nullptr;
+
+template <typename T>
+struct Bar {
+  Bar(T *p) : m_p(p) {
+    m_p = static_cast<T*>(NULL);
+    // CHECK-MESSAGES: :[[@LINE-1]]:27: warning: use nullptr
+    // CHECK-FIXES: m_p = static_cast<T*>(nullptr);
+
+    m_p = static_cast<T*>(reinterpret_cast<int*>((void*)NULL));
+    // CHECK-MESSAGES: :[[@LINE-1]]:27: warning: use nullptr
+    // CHECK-FIXES: m_p = static_cast<T*>(nullptr);
+
+    m_p = static_cast<T*>(p ? p : static_cast<void*>(g_null));
+    // CHECK-MESSAGES: :[[@LINE-1]]:54: warning: use nullptr
+    // CHECK-FIXES: m_p = static_cast<T*>(p ? p : static_cast<void*>(nullptr));
+
+    T *p2 = static_cast<T*>(reinterpret_cast<int*>((void*)NULL));
+    // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use nullptr
+    // CHECK-FIXES: T *p2 = static_cast<T*>(nullptr);
+
+    m_p = NULL;
+    // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: use nullptr
+    // CHECK-FIXES: m_p = nullptr;
+
+    int i = static_cast<int>(0.f);
+    T *i2 = static_cast<int>(0.f);
+    // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+    // CHECK-FIXES: T *i2 = nullptr;
+  }
+
+  T *m_p;
+};
+
+struct Baz {
+  Baz() : i(0) {}
+  int i;
+};
+
+void test_cxx_cases() {
+  Foo f(g_null);
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use nullptr
+  // CHECK-FIXES: Foo f(nullptr);
+
+  f.bar(NULL);
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use nullptr
+  // CHECK-FIXES: f.bar(nullptr);
+
+  f.baz(g_null);
+
+  f.m_p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use nullptr
+  // CHECK-FIXES: f.m_p1 = nullptr;
+
+  Bar<int> b(g_null);
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: use nullptr
+  // CHECK-FIXES: Bar<int> b(nullptr);
+
+  Baz b2;
+  int Baz::*memptr(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use nullptr
+  // CHECK-FIXES: int Baz::*memptr(nullptr);
+
+  memptr = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use nullptr
+  // CHECK-FIXES: memptr = nullptr;
+}
+
+void test_function_default_param1(void *p = 0);
+// CHECK-MESSAGES: :[[@LINE-1]]:45: warning: use nullptr
+// CHECK-FIXES: void test_function_default_param1(void *p = nullptr);
+
+void test_function_default_param2(void *p = NULL);
+// CHECK-MESSAGES: :[[@LINE-1]]:45: warning: use nullptr
+// CHECK-FIXES: void test_function_default_param2(void *p = nullptr);
+
+void test_function_default_param3(void *p = g_null);
+// CHECK-MESSAGES: :[[@LINE-1]]:45: warning: use nullptr
+// CHECK-FIXES: void test_function_default_param3(void *p = nullptr);
+
+void test_function(int *p) {}
+
+void test_function_no_ptr_param(int i) {}
+
+void test_function_call() {
+  test_function(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use nullptr
+  // CHECK-FIXES: test_function(nullptr);
+
+  test_function(NULL);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use nullptr
+  // CHECK-FIXES: test_function(nullptr);
+
+  test_function(g_null);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use nullptr
+  // CHECK-FIXES: test_function(nullptr);
+
+  test_function_no_ptr_param(0);
+}
+
+char *test_function_return1() {
+  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+void *test_function_return2() {
+  return NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+long *test_function_return3() {
+  return g_null;
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+int test_function_return4() {
+  return 0;
+}
+
+int test_function_return5() {
+  return NULL;
+}
+
+int test_function_return6() {
+  return g_null;
+}
+
+int *test_function_return_cast1() {
+  return(int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+int *test_function_return_cast2() {
+#define RET return
+  RET(int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use nullptr
+  // CHECK-FIXES: RET nullptr;
+#undef RET
+}
+
+// Test parentheses expressions resulting in a nullptr.
+int *test_parentheses_expression1() {
+  return(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return(nullptr);
+}
+
+int *test_parentheses_expression2() {
+  return(int(0.f));
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return(nullptr);
+}
+
+int *test_nested_parentheses_expression() {
+  return((((0))));
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+  // CHECK-FIXES: return((((nullptr))));
+}
+
+void *test_parentheses_explicit_cast() {
+  return(static_cast<void*>(0));
+  // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use nullptr
+  // CHECK-FIXES: return(static_cast<void*>(nullptr));
+}
+
+void *test_parentheses_explicit_cast_sequence1() {
+  return(static_cast<void*>(static_cast<int*>((void*)NULL)));
+  // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use nullptr
+  // CHECK-FIXES: return(static_cast<void*>(nullptr));
+}
+
+void *test_parentheses_explicit_cast_sequence2() {
+  return(static_cast<void*>(reinterpret_cast<int*>((float*)int(0.f))));
+  // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use nullptr
+  // CHECK-FIXES: return(static_cast<void*>(nullptr));
+}
+
+// Test explicit cast expressions resulting in nullptr.
+struct Bam {
+  Bam(int *a) {}
+  Bam(float *a) {}
+  Bam operator=(int *a) { return Bam(a); }
+  Bam operator=(float *a) { return Bam(a); }
+};
+
+void ambiguous_function(int *a) {}
+void ambiguous_function(float *a) {}
+void const_ambiguous_function(const int *p) {}
+void const_ambiguous_function(const float *p) {}
+
+void test_explicit_cast_ambiguous1() {
+  ambiguous_function((int*)0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:28: warning: use nullptr
+  // CHECK-FIXES: ambiguous_function((int*)nullptr);
+}
+
+void test_explicit_cast_ambiguous2() {
+  ambiguous_function((int*)(0));
+  // CHECK-MESSAGES: :[[@LINE-1]]:28: warning: use nullptr
+  // CHECK-FIXES: ambiguous_function((int*)nullptr);
+}
+
+void test_explicit_cast_ambiguous3() {
+  ambiguous_function(static_cast<int*>(reinterpret_cast<int*>((float*)0)));
+  // CHECK-MESSAGES: :[[@LINE-1]]:40: warning: use nullptr
+  // CHECK-FIXES: ambiguous_function(static_cast<int*>(nullptr));
+}
+
+Bam test_explicit_cast_ambiguous4() {
+  return(((int*)(0)));
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use nullptr
+  // CHECK-FIXES: return(((int*)nullptr));
+}
+
+void test_explicit_cast_ambiguous5() {
+  // Test for ambiguous overloaded constructors.
+  Bam k((int*)(0));
+  // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: use nullptr
+  // CHECK-FIXES: Bam k((int*)nullptr);
+
+  // Test for ambiguous overloaded operators.
+  k = (int*)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+  // CHECK-FIXES: k = (int*)nullptr;
+}
+
+void test_const_pointers_abiguous() {
+  const_ambiguous_function((int*)0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:34: warning: use nullptr
+  // CHECK-FIXES: const_ambiguous_function((int*)nullptr);
+}
+
+// Test where the implicit cast to null is surrounded by another implict cast
+// with possible explict casts in-between.
+void test_const_pointers() {
+  const int *const_p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p1 = nullptr;
+  const int *const_p2 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p2 = nullptr;
+  const int *const_p3 = (int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p3 = nullptr;
+  const int *const_p4 = (int)0.0f;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p4 = nullptr;
+  const int *const_p5 = (int*)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:31: warning: use nullptr
+  // CHECK-FIXES: const int *const_p5 = (int*)nullptr;
+  int *t;
+  const int *const_p6 = static_cast<int*>(t ? t : static_cast<int*>(0));
+  // CHECK-MESSAGES: :[[@LINE-1]]:69: warning: use nullptr
+  // CHECK-FIXES: const int *const_p6 = static_cast<int*>(t ? t : static_cast<int*>(nullptr));
+}
+
+
+// FIXME: currently, the check doesn't work as it should with templates.
+template<typename T>
+class A {
+ public:
+  A(T *p = NULL) {}
+
+  void f() {
+    Ptr = NULL;
+  }
+  T *Ptr;
+};
+
+template<typename T>
+T *f2(T *a = NULL) {
+  return a ? a : NULL;
+}

Added: clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr.cpp?rev=245434&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-use-nullptr.cpp Wed Aug 19 08:13:12 2015
@@ -0,0 +1,178 @@
+// RUN: $(dirname %s)/check_clang_tidy.sh %s modernize-use-nullptr %t \
+// RUN:   -config="{CheckOptions: [{key: modernize-use-nullptr.UserNullMacros, value: 'MY_NULL'}]}" \
+// RUN:   -- -std=c++11
+// REQUIRES: shell
+
+#define NULL 0
+
+namespace std {
+
+typedef decltype(nullptr) nullptr_t;
+
+} // namespace std
+
+// Just to make sure make_null() could have side effects.
+void external();
+
+std::nullptr_t make_null() {
+  external();
+  return nullptr;
+}
+
+void func() {
+  void *CallTest = make_null();
+
+  int var = 1;
+  void *CommaTest = (var+=2, make_null());
+
+  int *CastTest = static_cast<int*>(make_null());
+}
+
+void dummy(int*) {}
+void side_effect() {}
+
+#define MACRO_EXPANSION_HAS_NULL \
+  void foo() { \
+    dummy(0); \
+    dummy(NULL); \
+    side_effect(); \
+  }
+
+MACRO_EXPANSION_HAS_NULL;
+#undef MACRO_EXPANSION_HAS_NULL
+
+
+void test_macro_expansion1() {
+#define MACRO_EXPANSION_HAS_NULL \
+  dummy(NULL); \
+  side_effect();
+
+  MACRO_EXPANSION_HAS_NULL;
+
+#undef MACRO_EXPANSION_HAS_NULL
+}
+
+// Test macro expansion with cast sequence, PR15572.
+void test_macro_expansion2() {
+#define MACRO_EXPANSION_HAS_NULL \
+  dummy((int*)0); \
+  side_effect();
+
+  MACRO_EXPANSION_HAS_NULL;
+
+#undef MACRO_EXPANSION_HAS_NULL
+}
+
+void test_macro_expansion3() {
+#define MACRO_EXPANSION_HAS_NULL \
+  dummy(NULL); \
+  side_effect();
+
+#define OUTER_MACRO \
+  MACRO_EXPANSION_HAS_NULL; \
+  side_effect();
+
+  OUTER_MACRO;
+
+#undef OUTER_MACRO
+#undef MACRO_EXPANSION_HAS_NULL
+}
+
+void test_macro_expansion4() {
+#define MY_NULL NULL
+  int *p = MY_NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use nullptr [modernize-use-nullptr]
+  // CHECK-FIXES: int *p = nullptr;
+#undef MY_NULL
+}
+
+#define IS_EQ(x, y) if (x != y) return;
+void test_macro_args() {
+  int i = 0;
+  int *Ptr;
+
+  IS_EQ(static_cast<int*>(0), Ptr);
+  // CHECK-MESSAGES: :[[@LINE-1]]:27: warning: use nullptr
+  // CHECK-FIXES: IS_EQ(static_cast<int*>(nullptr), Ptr);
+
+  IS_EQ(0, Ptr);    // literal
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use nullptr
+  // CHECK-FIXES: IS_EQ(nullptr, Ptr);
+
+  IS_EQ(NULL, Ptr); // macro
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use nullptr
+  // CHECK-FIXES: IS_EQ(nullptr, Ptr);
+
+  // These are ok since the null literal is not spelled within a macro.
+#define myassert(x) if (!(x)) return;
+  myassert(0 == Ptr);
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use nullptr
+  // CHECK-FIXES: myassert(nullptr == Ptr);
+
+  myassert(NULL == Ptr);
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: use nullptr
+  // CHECK-FIXES: myassert(nullptr == Ptr);
+
+  // These are bad as the null literal is buried in a macro.
+#define BLAH(X) myassert(0 == (X));
+#define BLAH2(X) myassert(NULL == (X));
+  BLAH(Ptr);
+  BLAH2(Ptr);
+
+  // Same as above but testing extra macro expansion.
+#define EXPECT_NULL(X) IS_EQ(0, X);
+#define EXPECT_NULL2(X) IS_EQ(NULL, X);
+  EXPECT_NULL(Ptr);
+  EXPECT_NULL2(Ptr);
+
+  // Almost the same as above but now null literal is not in a macro so ok
+  // to transform.
+#define EQUALS_PTR(X) IS_EQ(X, Ptr);
+  EQUALS_PTR(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: use nullptr
+  // CHECK-FIXES: EQUALS_PTR(nullptr);
+  EQUALS_PTR(NULL);
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: use nullptr
+  // CHECK-FIXES: EQUALS_PTR(nullptr);
+
+  // Same as above but testing extra macro expansion.
+#define EQUALS_PTR_I(X) EQUALS_PTR(X)
+  EQUALS_PTR_I(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use nullptr
+  // CHECK-FIXES: EQUALS_PTR_I(nullptr);
+  EQUALS_PTR_I(NULL);
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use nullptr
+  // CHECK-FIXES: EQUALS_PTR_I(nullptr);
+
+  // Ok since null literal not within macro. However, now testing macro
+  // used as arg to another macro.
+#define decorate(EXPR) side_effect(); EXPR;
+  decorate(IS_EQ(NULL, Ptr));
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: use nullptr
+  // CHECK-FIXES: decorate(IS_EQ(nullptr, Ptr));
+  decorate(IS_EQ(0, Ptr));
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: use nullptr
+  // CHECK-FIXES: decorate(IS_EQ(nullptr, Ptr));
+
+  // This macro causes a NullToPointer cast to happen where 0 is assigned to z
+  // but the 0 literal cannot be replaced because it is also used as an
+  // integer in the comparison.
+#define INT_AND_PTR_USE(X) do { int *z = X; if (X == 4) break; } while(false)
+  INT_AND_PTR_USE(0);
+
+  // Both uses of X in this case result in NullToPointer casts so replacement
+  // is possible.
+#define PTR_AND_PTR_USE(X) do { int *z = X; if (X != z) break; } while(false)
+  PTR_AND_PTR_USE(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use nullptr
+  // CHECK-FIXES: PTR_AND_PTR_USE(nullptr);
+  PTR_AND_PTR_USE(NULL);
+  // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: use nullptr
+  // CHECK-FIXES: PTR_AND_PTR_USE(nullptr);
+
+#define OPTIONAL_CODE(...) __VA_ARGS__
+#define NOT_NULL dummy(0)
+#define CALL(X) X
+  OPTIONAL_CODE(NOT_NULL);
+  CALL(NOT_NULL);
+}




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