[clang-tools-extra] r245427 - [clang-tidy] Add loop-convert check to clang-tidy.

Alexander Kornienko via cfe-commits cfe-commits at lists.llvm.org
Wed Aug 19 02:11:47 PDT 2015


Author: alexfh
Date: Wed Aug 19 04:11:46 2015
New Revision: 245427

URL: http://llvm.org/viewvc/llvm-project?rev=245427&view=rev
Log:
[clang-tidy] Add loop-convert check to clang-tidy.

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

http://reviews.llvm.org/D12076

Patch by Angel Garcia!

Added:
    clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.cpp
    clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.h
    clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.cpp
    clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.h
    clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/
    clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/structures.h
    clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-basic.cpp
    clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-extra.cpp
    clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-negative.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=245427&r1=245426&r2=245427&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/CMakeLists.txt (original)
+++ clang-tools-extra/trunk/clang-tidy/modernize/CMakeLists.txt Wed Aug 19 04:11:46 2015
@@ -1,6 +1,8 @@
 set(LLVM_LINK_COMPONENTS support)
 
 add_clang_library(clangTidyModernizeModule
+  LoopConvertCheck.cpp
+  LoopConvertUtils.cpp
   ModernizeTidyModule.cpp
   PassByValueCheck.cpp
 

Added: clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.cpp?rev=245427&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.cpp (added)
+++ clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.cpp Wed Aug 19 04:11:46 2015
@@ -0,0 +1,668 @@
+//===--- LoopConvertCheck.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 "LoopConvertCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang;
+using namespace clang::ast_matchers;
+using namespace llvm;
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+const char LoopNameArray[] = "forLoopArray";
+const char LoopNameIterator[] = "forLoopIterator";
+const char LoopNamePseudoArray[] = "forLoopPseudoArray";
+const char ConditionBoundName[] = "conditionBound";
+const char ConditionVarName[] = "conditionVar";
+const char IncrementVarName[] = "incrementVar";
+const char InitVarName[] = "initVar";
+const char BeginCallName[] = "beginCall";
+const char EndCallName[] = "endCall";
+const char ConditionEndVarName[] = "conditionEndVar";
+const char EndVarName[] = "endVar";
+const char DerefByValueResultName[] = "derefByValueResult";
+const char DerefByRefResultName[] = "derefByRefResult";
+
+// shared matchers
+static const TypeMatcher AnyType = anything();
+
+static const StatementMatcher IntegerComparisonMatcher =
+    expr(ignoringParenImpCasts(
+        declRefExpr(to(varDecl(hasType(isInteger())).bind(ConditionVarName)))));
+
+static const DeclarationMatcher InitToZeroMatcher =
+    varDecl(hasInitializer(ignoringParenImpCasts(integerLiteral(equals(0)))))
+        .bind(InitVarName);
+
+static const StatementMatcher IncrementVarMatcher =
+    declRefExpr(to(varDecl(hasType(isInteger())).bind(IncrementVarName)));
+
+/// \brief The matcher for loops over arrays.
+///
+/// In this general example, assuming 'j' and 'k' are of integral type:
+/// \code
+///   for (int i = 0; j < 3 + 2; ++k) { ... }
+/// \endcode
+/// The following string identifiers are bound to these parts of the AST:
+///   ConditionVarName: 'j' (as a VarDecl)
+///   ConditionBoundName: '3 + 2' (as an Expr)
+///   InitVarName: 'i' (as a VarDecl)
+///   IncrementVarName: 'k' (as a VarDecl)
+///   LoopName: The entire for loop (as a ForStmt)
+///
+/// Client code will need to make sure that:
+///   - The three index variables identified by the matcher are the same
+///     VarDecl.
+///   - The index variable is only used as an array index.
+///   - All arrays indexed by the loop are the same.
+StatementMatcher makeArrayLoopMatcher() {
+  StatementMatcher ArrayBoundMatcher =
+      expr(hasType(isInteger())).bind(ConditionBoundName);
+
+  return forStmt(
+             hasLoopInit(declStmt(hasSingleDecl(InitToZeroMatcher))),
+             hasCondition(anyOf(
+                 binaryOperator(hasOperatorName("<"),
+                                hasLHS(IntegerComparisonMatcher),
+                                hasRHS(ArrayBoundMatcher)),
+                 binaryOperator(hasOperatorName(">"), hasLHS(ArrayBoundMatcher),
+                                hasRHS(IntegerComparisonMatcher)))),
+             hasIncrement(unaryOperator(hasOperatorName("++"),
+                                        hasUnaryOperand(IncrementVarMatcher))))
+      .bind(LoopNameArray);
+}
+
+/// \brief The matcher used for iterator-based for loops.
+///
+/// This matcher is more flexible than array-based loops. It will match
+/// catch loops of the following textual forms (regardless of whether the
+/// iterator type is actually a pointer type or a class type):
+///
+/// Assuming f, g, and h are of type containerType::iterator,
+/// \code
+///   for (containerType::iterator it = container.begin(),
+///        e = createIterator(); f != g; ++h) { ... }
+///   for (containerType::iterator it = container.begin();
+///        f != anotherContainer.end(); ++h) { ... }
+/// \endcode
+/// The following string identifiers are bound to the parts of the AST:
+///   InitVarName: 'it' (as a VarDecl)
+///   ConditionVarName: 'f' (as a VarDecl)
+///   LoopName: The entire for loop (as a ForStmt)
+///   In the first example only:
+///     EndVarName: 'e' (as a VarDecl)
+///     ConditionEndVarName: 'g' (as a VarDecl)
+///   In the second example only:
+///     EndCallName: 'container.end()' (as a CXXMemberCallExpr)
+///
+/// Client code will need to make sure that:
+///   - The iterator variables 'it', 'f', and 'h' are the same.
+///   - The two containers on which 'begin' and 'end' are called are the same.
+///   - If the end iterator variable 'g' is defined, it is the same as 'f'.
+StatementMatcher makeIteratorLoopMatcher() {
+  StatementMatcher BeginCallMatcher =
+      memberCallExpr(argumentCountIs(0), callee(methodDecl(hasName("begin"))))
+          .bind(BeginCallName);
+
+  DeclarationMatcher InitDeclMatcher =
+      varDecl(hasInitializer(anyOf(ignoringParenImpCasts(BeginCallMatcher),
+                                   materializeTemporaryExpr(
+                                       ignoringParenImpCasts(BeginCallMatcher)),
+                                   hasDescendant(BeginCallMatcher))))
+          .bind(InitVarName);
+
+  DeclarationMatcher EndDeclMatcher =
+      varDecl(hasInitializer(anything())).bind(EndVarName);
+
+  StatementMatcher EndCallMatcher =
+      memberCallExpr(argumentCountIs(0), callee(methodDecl(hasName("end"))));
+
+  StatementMatcher IteratorBoundMatcher =
+      expr(anyOf(ignoringParenImpCasts(
+                     declRefExpr(to(varDecl().bind(ConditionEndVarName)))),
+                 ignoringParenImpCasts(expr(EndCallMatcher).bind(EndCallName)),
+                 materializeTemporaryExpr(ignoringParenImpCasts(
+                     expr(EndCallMatcher).bind(EndCallName)))));
+
+  StatementMatcher IteratorComparisonMatcher = expr(
+      ignoringParenImpCasts(declRefExpr(to(varDecl().bind(ConditionVarName)))));
+
+  StatementMatcher OverloadedNEQMatcher =
+      operatorCallExpr(hasOverloadedOperatorName("!="), argumentCountIs(2),
+                       hasArgument(0, IteratorComparisonMatcher),
+                       hasArgument(1, IteratorBoundMatcher));
+
+  // This matcher tests that a declaration is a CXXRecordDecl that has an
+  // overloaded operator*(). If the operator*() returns by value instead of by
+  // reference then the return type is tagged with DerefByValueResultName.
+  internal::Matcher<VarDecl> TestDerefReturnsByValue =
+      hasType(recordDecl(hasMethod(allOf(
+          hasOverloadedOperatorName("*"),
+          anyOf(
+              // Tag the return type if it's by value.
+              returns(qualType(unless(hasCanonicalType(referenceType())))
+                          .bind(DerefByValueResultName)),
+              returns(
+                  // Skip loops where the iterator's operator* returns an
+                  // rvalue reference. This is just weird.
+                  qualType(unless(hasCanonicalType(rValueReferenceType())))
+                      .bind(DerefByRefResultName)))))));
+
+  return forStmt(
+             hasLoopInit(anyOf(declStmt(declCountIs(2),
+                                        containsDeclaration(0, InitDeclMatcher),
+                                        containsDeclaration(1, EndDeclMatcher)),
+                               declStmt(hasSingleDecl(InitDeclMatcher)))),
+             hasCondition(
+                 anyOf(binaryOperator(hasOperatorName("!="),
+                                      hasLHS(IteratorComparisonMatcher),
+                                      hasRHS(IteratorBoundMatcher)),
+                       binaryOperator(hasOperatorName("!="),
+                                      hasLHS(IteratorBoundMatcher),
+                                      hasRHS(IteratorComparisonMatcher)),
+                       OverloadedNEQMatcher)),
+             hasIncrement(anyOf(
+                 unaryOperator(hasOperatorName("++"),
+                               hasUnaryOperand(declRefExpr(
+                                   to(varDecl(hasType(pointsTo(AnyType)))
+                                          .bind(IncrementVarName))))),
+                 operatorCallExpr(
+                     hasOverloadedOperatorName("++"),
+                     hasArgument(
+                         0, declRefExpr(to(varDecl(TestDerefReturnsByValue)
+                                               .bind(IncrementVarName))))))))
+      .bind(LoopNameIterator);
+}
+
+/// \brief The matcher used for array-like containers (pseudoarrays).
+///
+/// This matcher is more flexible than array-based loops. It will match
+/// loops of the following textual forms (regardless of whether the
+/// iterator type is actually a pointer type or a class type):
+///
+/// Assuming f, g, and h are of type containerType::iterator,
+/// \code
+///   for (int i = 0, j = container.size(); f < g; ++h) { ... }
+///   for (int i = 0; f < container.size(); ++h) { ... }
+/// \endcode
+/// The following string identifiers are bound to the parts of the AST:
+///   InitVarName: 'i' (as a VarDecl)
+///   ConditionVarName: 'f' (as a VarDecl)
+///   LoopName: The entire for loop (as a ForStmt)
+///   In the first example only:
+///     EndVarName: 'j' (as a VarDecl)
+///     ConditionEndVarName: 'g' (as a VarDecl)
+///   In the second example only:
+///     EndCallName: 'container.size()' (as a CXXMemberCallExpr)
+///
+/// Client code will need to make sure that:
+///   - The index variables 'i', 'f', and 'h' are the same.
+///   - The containers on which 'size()' is called is the container indexed.
+///   - The index variable is only used in overloaded operator[] or
+///     container.at().
+///   - If the end iterator variable 'g' is defined, it is the same as 'j'.
+///   - The container's iterators would not be invalidated during the loop.
+StatementMatcher makePseudoArrayLoopMatcher() {
+  // Test that the incoming type has a record declaration that has methods
+  // called 'begin' and 'end'. If the incoming type is const, then make sure
+  // these methods are also marked const.
+  //
+  // FIXME: To be completely thorough this matcher should also ensure the
+  // return type of begin/end is an iterator that dereferences to the same as
+  // what operator[] or at() returns. Such a test isn't likely to fail except
+  // for pathological cases.
+  //
+  // FIXME: Also, a record doesn't necessarily need begin() and end(). Free
+  // functions called begin() and end() taking the container as an argument
+  // are also allowed.
+  TypeMatcher RecordWithBeginEnd = qualType(
+      anyOf(qualType(isConstQualified(),
+                     hasDeclaration(recordDecl(
+                         hasMethod(methodDecl(hasName("begin"), isConst())),
+                         hasMethod(methodDecl(hasName("end"),
+                                              isConst())))) // hasDeclaration
+                     ),                                     // qualType
+            qualType(unless(isConstQualified()),
+                     hasDeclaration(
+                         recordDecl(hasMethod(hasName("begin")),
+                                    hasMethod(hasName("end"))))) // qualType
+            ));
+
+  StatementMatcher SizeCallMatcher = memberCallExpr(
+      argumentCountIs(0),
+      callee(methodDecl(anyOf(hasName("size"), hasName("length")))),
+      on(anyOf(hasType(pointsTo(RecordWithBeginEnd)),
+               hasType(RecordWithBeginEnd))));
+
+  StatementMatcher EndInitMatcher =
+      expr(anyOf(ignoringParenImpCasts(expr(SizeCallMatcher).bind(EndCallName)),
+                 explicitCastExpr(hasSourceExpression(ignoringParenImpCasts(
+                     expr(SizeCallMatcher).bind(EndCallName))))));
+
+  DeclarationMatcher EndDeclMatcher =
+      varDecl(hasInitializer(EndInitMatcher)).bind(EndVarName);
+
+  StatementMatcher IndexBoundMatcher =
+      expr(anyOf(ignoringParenImpCasts(declRefExpr(to(
+                     varDecl(hasType(isInteger())).bind(ConditionEndVarName)))),
+                 EndInitMatcher));
+
+  return forStmt(
+             hasLoopInit(
+                 anyOf(declStmt(declCountIs(2),
+                                containsDeclaration(0, InitToZeroMatcher),
+                                containsDeclaration(1, EndDeclMatcher)),
+                       declStmt(hasSingleDecl(InitToZeroMatcher)))),
+             hasCondition(anyOf(
+                 binaryOperator(hasOperatorName("<"),
+                                hasLHS(IntegerComparisonMatcher),
+                                hasRHS(IndexBoundMatcher)),
+                 binaryOperator(hasOperatorName(">"), hasLHS(IndexBoundMatcher),
+                                hasRHS(IntegerComparisonMatcher)))),
+             hasIncrement(unaryOperator(hasOperatorName("++"),
+                                        hasUnaryOperand(IncrementVarMatcher))))
+      .bind(LoopNamePseudoArray);
+}
+
+/// \brief Determine whether Init appears to be an initializing an iterator.
+///
+/// If it is, returns the object whose begin() or end() method is called, and
+/// the output parameter isArrow is set to indicate whether the initialization
+/// is called via . or ->.
+static const Expr *getContainerFromBeginEndCall(const Expr *Init, bool IsBegin,
+                                                bool *IsArrow) {
+  // FIXME: Maybe allow declaration/initialization outside of the for loop.
+  const auto *TheCall =
+      dyn_cast_or_null<CXXMemberCallExpr>(digThroughConstructors(Init));
+  if (!TheCall || TheCall->getNumArgs() != 0)
+    return nullptr;
+
+  const auto *Member = dyn_cast<MemberExpr>(TheCall->getCallee());
+  if (!Member)
+    return nullptr;
+  StringRef Name = Member->getMemberDecl()->getName();
+  StringRef TargetName = IsBegin ? "begin" : "end";
+  if (Name != TargetName)
+    return nullptr;
+
+  const Expr *SourceExpr = Member->getBase();
+  if (!SourceExpr)
+    return nullptr;
+
+  *IsArrow = Member->isArrow();
+  return SourceExpr;
+}
+
+/// \brief Determines the container whose begin() and end() functions are called
+/// for an iterator-based loop.
+///
+/// BeginExpr must be a member call to a function named "begin()", and EndExpr
+/// must be a member.
+static const Expr *findContainer(ASTContext *Context, const Expr *BeginExpr,
+                                 const Expr *EndExpr,
+                                 bool *ContainerNeedsDereference) {
+  // Now that we know the loop variable and test expression, make sure they are
+  // valid.
+  bool BeginIsArrow = false;
+  bool EndIsArrow = false;
+  const Expr *BeginContainerExpr =
+      getContainerFromBeginEndCall(BeginExpr, /*IsBegin=*/true, &BeginIsArrow);
+  if (!BeginContainerExpr)
+    return nullptr;
+
+  const Expr *EndContainerExpr =
+      getContainerFromBeginEndCall(EndExpr, /*IsBegin=*/false, &EndIsArrow);
+  // Disallow loops that try evil things like this (note the dot and arrow):
+  //  for (IteratorType It = Obj.begin(), E = Obj->end(); It != E; ++It) { }
+  if (!EndContainerExpr || BeginIsArrow != EndIsArrow ||
+      !areSameExpr(Context, EndContainerExpr, BeginContainerExpr))
+    return nullptr;
+
+  *ContainerNeedsDereference = BeginIsArrow;
+  return BeginContainerExpr;
+}
+
+/// \brief Obtain the original source code text from a SourceRange.
+static StringRef getStringFromRange(SourceManager &SourceMgr,
+                                    const LangOptions &LangOpts,
+                                    SourceRange Range) {
+  if (SourceMgr.getFileID(Range.getBegin()) !=
+      SourceMgr.getFileID(Range.getEnd()))
+    return nullptr;
+
+  return Lexer::getSourceText(CharSourceRange(Range, true), SourceMgr,
+                              LangOpts);
+}
+
+/// \brief If the given expression is actually a DeclRefExpr, find and return
+/// the underlying VarDecl; otherwise, return NULL.
+static const VarDecl *getReferencedVariable(const Expr *E) {
+  if (const DeclRefExpr *DRE = getDeclRef(E))
+    return dyn_cast<VarDecl>(DRE->getDecl());
+  return nullptr;
+}
+
+/// \brief Returns true when the given expression is a member expression
+/// whose base is `this` (implicitly or not).
+static bool isDirectMemberExpr(const Expr *E) {
+  if (const auto *Member = dyn_cast<MemberExpr>(E->IgnoreParenImpCasts()))
+    return isa<CXXThisExpr>(Member->getBase()->IgnoreParenImpCasts());
+  return false;
+}
+
+LoopConvertCheck::LoopConvertCheck(StringRef Name, ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context), TUInfo(new TUTrackingInfo),
+      MinConfidence(StringSwitch<Confidence::Level>(
+                        Options.get("MinConfidence", "reasonable"))
+                        .Case("safe", Confidence::CL_Safe)
+                        .Case("risky", Confidence::CL_Risky)
+                        .Default(Confidence::CL_Reasonable)) {}
+
+void LoopConvertCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  SmallVector<std::string, 3> Confs{"risky", "reasonable", "safe"};
+  Options.store(Opts, "MinConfidence", Confs[static_cast<int>(MinConfidence)]);
+}
+
+/// \brief Computes the changes needed to convert a given for loop, and
+/// applies it.
+void LoopConvertCheck::doConversion(
+    ASTContext *Context, const VarDecl *IndexVar, const VarDecl *MaybeContainer,
+    StringRef ContainerString, const UsageResult &Usages,
+    const DeclStmt *AliasDecl, bool AliasUseRequired, bool AliasFromForInit,
+    const ForStmt *TheLoop, bool ContainerNeedsDereference, bool DerefByValue,
+    bool DerefByConstRef) {
+  auto Diag = diag(TheLoop->getForLoc(), "use range-based for loop instead");
+
+  std::string VarName;
+  bool VarNameFromAlias = (Usages.size() == 1) && AliasDecl;
+  bool AliasVarIsRef = false;
+
+  if (VarNameFromAlias) {
+    const auto *AliasVar = cast<VarDecl>(AliasDecl->getSingleDecl());
+    VarName = AliasVar->getName().str();
+    AliasVarIsRef = AliasVar->getType()->isReferenceType();
+
+    // We keep along the entire DeclStmt to keep the correct range here.
+    const SourceRange &ReplaceRange = AliasDecl->getSourceRange();
+
+    std::string ReplacementText;
+    if (AliasUseRequired) {
+      ReplacementText = VarName;
+    } else if (AliasFromForInit) {
+      // FIXME: Clang includes the location of the ';' but only for DeclStmt's
+      // in a for loop's init clause. Need to put this ';' back while removing
+      // the declaration of the alias variable. This is probably a bug.
+      ReplacementText = ";";
+    }
+
+    Diag << FixItHint::CreateReplacement(
+        CharSourceRange::getTokenRange(ReplaceRange), ReplacementText);
+    // No further replacements are made to the loop, since the iterator or index
+    // was used exactly once - in the initialization of AliasVar.
+  } else {
+    VariableNamer Namer(&TUInfo->getGeneratedDecls(),
+                        &TUInfo->getParentFinder().getStmtToParentStmtMap(),
+                        TheLoop, IndexVar, MaybeContainer, Context);
+    VarName = Namer.createIndexName();
+    // First, replace all usages of the array subscript expression with our new
+    // variable.
+    for (const auto &I : Usages) {
+      StringRef ReplaceText = I.IsArrow ? VarName + "." : VarName;
+      TUInfo->getReplacedVars().insert(std::make_pair(TheLoop, IndexVar));
+      Diag << FixItHint::CreateReplacement(
+          CharSourceRange::getTokenRange(I.Range), ReplaceText);
+    }
+  }
+
+  // Now, we need to construct the new range expression.
+  SourceRange ParenRange(TheLoop->getLParenLoc(), TheLoop->getRParenLoc());
+
+  QualType AutoRefType = Context->getAutoDeductType();
+
+  // If the new variable name is from the aliased variable, then the reference
+  // type for the new variable should only be used if the aliased variable was
+  // declared as a reference.
+  if (!VarNameFromAlias || AliasVarIsRef) {
+    // If an iterator's operator*() returns a 'T&' we can bind that to 'auto&'.
+    // If operator*() returns 'T' we can bind that to 'auto&&' which will deduce
+    // to 'T&&&'.
+    if (DerefByValue) {
+      AutoRefType = Context->getRValueReferenceType(AutoRefType);
+    } else {
+      if (DerefByConstRef)
+        AutoRefType = Context->getConstType(AutoRefType);
+      AutoRefType = Context->getLValueReferenceType(AutoRefType);
+    }
+  }
+
+  StringRef MaybeDereference = ContainerNeedsDereference ? "*" : "";
+  StringRef TypeString = AutoRefType.getAsString();
+  StringRef Range = ("(" + TypeString + " " + VarName + " : " +
+                     MaybeDereference + ContainerString + ")")
+                        .str();
+
+  Diag << FixItHint::CreateReplacement(
+      CharSourceRange::getTokenRange(ParenRange), Range);
+  TUInfo->getGeneratedDecls().insert(make_pair(TheLoop, VarName));
+}
+
+/// \brief Determine if the change should be deferred or rejected, returning
+/// text which refers to the container iterated over if the change should
+/// proceed.
+StringRef LoopConvertCheck::checkRejections(ASTContext *Context,
+                                            const Expr *ContainerExpr,
+                                            const ForStmt *TheLoop) {
+  // If we already modified the reange of this for loop, don't do any further
+  // updates on this iteration.
+  if (TUInfo->getReplacedVars().count(TheLoop))
+    return "";
+
+  Context->getTranslationUnitDecl();
+  TUInfo->getParentFinder();
+  TUInfo->getParentFinder().gatherAncestors(Context->getTranslationUnitDecl());
+  // Ensure that we do not try to move an expression dependent on a local
+  // variable declared inside the loop outside of it.
+  DependencyFinderASTVisitor DependencyFinder(
+      &TUInfo->getParentFinder().getStmtToParentStmtMap(),
+      &TUInfo->getParentFinder().getDeclToParentStmtMap(),
+      &TUInfo->getReplacedVars(), TheLoop);
+
+  // FIXME: Determine when the external dependency isn't an expression converted
+  // by another loop.
+  if (DependencyFinder.dependsOnInsideVariable(ContainerExpr))
+    return "";
+
+  StringRef ContainerString;
+  if (isa<CXXThisExpr>(ContainerExpr->IgnoreParenImpCasts())) {
+    ContainerString = "this";
+  } else {
+    ContainerString =
+        getStringFromRange(Context->getSourceManager(), Context->getLangOpts(),
+                           ContainerExpr->getSourceRange());
+  }
+
+  return ContainerString;
+}
+
+/// \brief Given a loop header that would be convertible, discover all usages
+/// of the index variable and convert the loop if possible.
+void LoopConvertCheck::findAndVerifyUsages(
+    ASTContext *Context, const VarDecl *LoopVar, const VarDecl *EndVar,
+    const Expr *ContainerExpr, const Expr *BoundExpr,
+    bool ContainerNeedsDereference, bool DerefByValue, bool DerefByConstRef,
+    const ForStmt *TheLoop, LoopFixerKind FixerKind) {
+  ForLoopIndexUseVisitor Finder(Context, LoopVar, EndVar, ContainerExpr,
+                                BoundExpr, ContainerNeedsDereference);
+
+  if (ContainerExpr) {
+    ComponentFinderASTVisitor ComponentFinder;
+    ComponentFinder.findExprComponents(ContainerExpr->IgnoreParenImpCasts());
+    Finder.addComponents(ComponentFinder.getComponents());
+  }
+
+  if (!Finder.findAndVerifyUsages(TheLoop->getBody()))
+    return;
+
+  Confidence ConfidenceLevel(Finder.getConfidenceLevel());
+  if (FixerKind == LFK_Array) {
+    // The array being indexed by IndexVar was discovered during traversal.
+    ContainerExpr = Finder.getContainerIndexed()->IgnoreParenImpCasts();
+    // Very few loops are over expressions that generate arrays rather than
+    // array variables. Consider loops over arrays that aren't just represented
+    // by a variable to be risky conversions.
+    if (!getReferencedVariable(ContainerExpr) &&
+        !isDirectMemberExpr(ContainerExpr))
+      ConfidenceLevel.lowerTo(Confidence::CL_Risky);
+  }
+
+  StringRef ContainerString = checkRejections(Context, ContainerExpr, TheLoop);
+
+  if (ContainerString.empty() || ConfidenceLevel.getLevel() < MinConfidence)
+    return;
+
+  doConversion(Context, LoopVar, getReferencedVariable(ContainerExpr),
+               ContainerString, Finder.getUsages(), Finder.getAliasDecl(),
+               Finder.aliasUseRequired(), Finder.aliasFromForInit(), TheLoop,
+               ContainerNeedsDereference, DerefByValue, DerefByConstRef);
+}
+
+void LoopConvertCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(makeArrayLoopMatcher(), this);
+  Finder->addMatcher(makeIteratorLoopMatcher(), this);
+  Finder->addMatcher(makePseudoArrayLoopMatcher(), this);
+}
+
+void LoopConvertCheck::check(const MatchFinder::MatchResult &Result) {
+  const BoundNodes &Nodes = Result.Nodes;
+  Confidence ConfidenceLevel(Confidence::CL_Safe);
+  ASTContext *Context = Result.Context;
+
+  const ForStmt *TheLoop;
+  LoopFixerKind FixerKind;
+
+  if ((TheLoop = Nodes.getStmtAs<ForStmt>(LoopNameArray))) {
+    FixerKind = LFK_Array;
+  } else if ((TheLoop = Nodes.getStmtAs<ForStmt>(LoopNameIterator))) {
+    FixerKind = LFK_Iterator;
+  } else {
+    TheLoop = Nodes.getStmtAs<ForStmt>(LoopNamePseudoArray);
+    assert(TheLoop && "Bad Callback. No for statement");
+    FixerKind = LFK_PseudoArray;
+  }
+
+  // Check that we have exactly one index variable and at most one end variable.
+  const auto *LoopVar = Nodes.getDeclAs<VarDecl>(IncrementVarName);
+  const auto *CondVar = Nodes.getDeclAs<VarDecl>(ConditionVarName);
+  const auto *InitVar = Nodes.getDeclAs<VarDecl>(InitVarName);
+  if (!areSameVariable(LoopVar, CondVar) || !areSameVariable(LoopVar, InitVar))
+    return;
+  const auto *EndVar = Nodes.getDeclAs<VarDecl>(EndVarName);
+  const auto *ConditionEndVar = Nodes.getDeclAs<VarDecl>(ConditionEndVarName);
+  if (EndVar && !areSameVariable(EndVar, ConditionEndVar))
+    return;
+
+  // If the end comparison isn't a variable, we can try to work with the
+  // expression the loop variable is being tested against instead.
+  const auto *EndCall = Nodes.getStmtAs<CXXMemberCallExpr>(EndCallName);
+  const auto *BoundExpr = Nodes.getStmtAs<Expr>(ConditionBoundName);
+  // If the loop calls end()/size() after each iteration, lower our confidence
+  // level.
+  if (FixerKind != LFK_Array && !EndVar)
+    ConfidenceLevel.lowerTo(Confidence::CL_Reasonable);
+
+  const Expr *ContainerExpr = nullptr;
+  bool DerefByValue = false;
+  bool DerefByConstRef = false;
+  bool ContainerNeedsDereference = false;
+  // FIXME: Try to put most of this logic inside a matcher. Currently, matchers
+  // don't allow the ight-recursive checks in digThroughConstructors.
+  if (FixerKind == LFK_Iterator) {
+    ContainerExpr = findContainer(Context, LoopVar->getInit(),
+                                  EndVar ? EndVar->getInit() : EndCall,
+                                  &ContainerNeedsDereference);
+
+    QualType InitVarType = InitVar->getType();
+    QualType CanonicalInitVarType = InitVarType.getCanonicalType();
+
+    const auto *BeginCall = Nodes.getNodeAs<CXXMemberCallExpr>(BeginCallName);
+    assert(BeginCall && "Bad Callback. No begin call expression");
+    QualType CanonicalBeginType =
+        BeginCall->getMethodDecl()->getReturnType().getCanonicalType();
+    if (CanonicalBeginType->isPointerType() &&
+        CanonicalInitVarType->isPointerType()) {
+      QualType BeginPointeeType = CanonicalBeginType->getPointeeType();
+      QualType InitPointeeType = CanonicalInitVarType->getPointeeType();
+      // If the initializer and the variable are both pointers check if the
+      // un-qualified pointee types match otherwise we don't use auto.
+      if (!Context->hasSameUnqualifiedType(InitPointeeType, BeginPointeeType))
+        return;
+    } else {
+      // Check for qualified types to avoid conversions from non-const to const
+      // iterator types.
+      if (!Context->hasSameType(CanonicalInitVarType, CanonicalBeginType))
+        return;
+    }
+
+    DerefByValue = Nodes.getNodeAs<QualType>(DerefByValueResultName) != nullptr;
+    if (!DerefByValue) {
+      if (const auto *DerefType =
+              Nodes.getNodeAs<QualType>(DerefByRefResultName)) {
+        // A node will only be bound with DerefByRefResultName if we're dealing
+        // with a user-defined iterator type. Test the const qualification of
+        // the reference type.
+        DerefByConstRef = (*DerefType)
+                              ->getAs<ReferenceType>()
+                              ->getPointeeType()
+                              .isConstQualified();
+      } else {
+        // By nature of the matcher this case is triggered only for built-in
+        // iterator types (i.e. pointers).
+        assert(isa<PointerType>(CanonicalInitVarType) &&
+               "Non-class iterator type is not a pointer type");
+        QualType InitPointeeType = CanonicalInitVarType->getPointeeType();
+        QualType BeginPointeeType = CanonicalBeginType->getPointeeType();
+        // If the initializer and variable have both the same type just use auto
+        // otherwise we test for const qualification of the pointed-at type.
+        if (!Context->hasSameType(InitPointeeType, BeginPointeeType))
+          DerefByConstRef = InitPointeeType.isConstQualified();
+      }
+    } else {
+      // If the dereference operator returns by value then test for the
+      // canonical const qualification of the init variable type.
+      DerefByConstRef = CanonicalInitVarType.isConstQualified();
+    }
+  } else if (FixerKind == LFK_PseudoArray) {
+    if (!EndCall)
+      return;
+    ContainerExpr = EndCall->getImplicitObjectArgument();
+    const auto *Member = dyn_cast<MemberExpr>(EndCall->getCallee());
+    if (!Member)
+      return;
+    ContainerNeedsDereference = Member->isArrow();
+  }
+
+  // We must know the container or an array length bound.
+  if (!ContainerExpr && !BoundExpr)
+    return;
+
+  if (ConfidenceLevel.getLevel() < MinConfidence)
+    return;
+
+  findAndVerifyUsages(Context, LoopVar, EndVar, ContainerExpr, BoundExpr,
+                      ContainerNeedsDereference, DerefByValue, DerefByConstRef,
+                      TheLoop, FixerKind);
+}
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang

Added: clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.h
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.h?rev=245427&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.h (added)
+++ clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.h Wed Aug 19 04:11:46 2015
@@ -0,0 +1,52 @@
+//===--- LoopConvertCheck.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_LOOP_CONVERT_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_LOOP_CONVERT_H
+
+#include "../ClangTidy.h"
+#include "LoopConvertUtils.h"
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+class LoopConvertCheck : public ClangTidyCheck {
+public:
+  LoopConvertCheck(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:
+  void doConversion(ASTContext *Context, const VarDecl *IndexVar,
+                    const VarDecl *MaybeContainer, StringRef ContainerString,
+                    const UsageResult &Usages, const DeclStmt *AliasDecl,
+                    bool AliasUseRequired, bool AliasFromForInit,
+                    const ForStmt *TheLoop, bool ContainerNeedsDereference,
+                    bool DerefByValue, bool DerefByConstRef);
+
+  StringRef checkRejections(ASTContext *Context, const Expr *ContainerExpr,
+                            const ForStmt *TheLoop);
+
+  void findAndVerifyUsages(ASTContext *Context, const VarDecl *LoopVar,
+                           const VarDecl *EndVar, const Expr *ContainerExpr,
+                           const Expr *BoundExpr,
+                           bool ContainerNeedsDereference, bool DerefByValue,
+                           bool DerefByConstRef, const ForStmt *TheLoop,
+                           LoopFixerKind FixerKind);
+  std::unique_ptr<TUTrackingInfo> TUInfo;
+  Confidence::Level MinConfidence;
+};
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_LOOP_CONVERT_H

Added: clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.cpp?rev=245427&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.cpp (added)
+++ clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.cpp Wed Aug 19 04:11:46 2015
@@ -0,0 +1,817 @@
+//===--- LoopConvertUtils.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 "LoopConvertUtils.h"
+
+using namespace clang::ast_matchers;
+using namespace clang::tooling;
+using namespace clang;
+using namespace llvm;
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+/// \brief Tracks a stack of parent statements during traversal.
+///
+/// All this really does is inject push_back() before running
+/// RecursiveASTVisitor::TraverseStmt() and pop_back() afterwards. The Stmt atop
+/// the stack is the parent of the current statement (NULL for the topmost
+/// statement).
+bool StmtAncestorASTVisitor::TraverseStmt(Stmt *Statement) {
+  StmtAncestors.insert(std::make_pair(Statement, StmtStack.back()));
+  StmtStack.push_back(Statement);
+  RecursiveASTVisitor<StmtAncestorASTVisitor>::TraverseStmt(Statement);
+  StmtStack.pop_back();
+  return true;
+}
+
+/// \brief Keep track of the DeclStmt associated with each VarDecl.
+///
+/// Combined with StmtAncestors, this provides roughly the same information as
+/// Scope, as we can map a VarDecl to its DeclStmt, then walk up the parent tree
+/// using StmtAncestors.
+bool StmtAncestorASTVisitor::VisitDeclStmt(DeclStmt *Decls) {
+  for (const auto *decl : Decls->decls()) {
+    if (const auto *V = dyn_cast<VarDecl>(decl))
+      DeclParents.insert(std::make_pair(V, Decls));
+  }
+  return true;
+}
+
+/// \brief record the DeclRefExpr as part of the parent expression.
+bool ComponentFinderASTVisitor::VisitDeclRefExpr(DeclRefExpr *E) {
+  Components.push_back(E);
+  return true;
+}
+
+/// \brief record the MemberExpr as part of the parent expression.
+bool ComponentFinderASTVisitor::VisitMemberExpr(MemberExpr *Member) {
+  Components.push_back(Member);
+  return true;
+}
+
+/// \brief Forward any DeclRefExprs to a check on the referenced variable
+/// declaration.
+bool DependencyFinderASTVisitor::VisitDeclRefExpr(DeclRefExpr *DeclRef) {
+  if (auto *V = dyn_cast_or_null<VarDecl>(DeclRef->getDecl()))
+    return VisitVarDecl(V);
+  return true;
+}
+
+/// \brief Determine if any this variable is declared inside the ContainingStmt.
+bool DependencyFinderASTVisitor::VisitVarDecl(VarDecl *V) {
+  const Stmt *Curr = DeclParents->lookup(V);
+  // First, see if the variable was declared within an inner scope of the loop.
+  while (Curr != nullptr) {
+    if (Curr == ContainingStmt) {
+      DependsOnInsideVariable = true;
+      return false;
+    }
+    Curr = StmtParents->lookup(Curr);
+  }
+
+  // Next, check if the variable was removed from existence by an earlier
+  // iteration.
+  for (const auto &I : *ReplacedVars) {
+    if (I.second == V) {
+      DependsOnInsideVariable = true;
+      return false;
+    }
+  }
+  return true;
+}
+
+/// \brief If we already created a variable for TheLoop, check to make sure
+/// that the name was not already taken.
+bool DeclFinderASTVisitor::VisitForStmt(ForStmt *TheLoop) {
+  StmtGeneratedVarNameMap::const_iterator I = GeneratedDecls->find(TheLoop);
+  if (I != GeneratedDecls->end() && I->second == Name) {
+    Found = true;
+    return false;
+  }
+  return true;
+}
+
+/// \brief If any named declaration within the AST subtree has the same name,
+/// then consider Name already taken.
+bool DeclFinderASTVisitor::VisitNamedDecl(NamedDecl *D) {
+  const IdentifierInfo *Ident = D->getIdentifier();
+  if (Ident && Ident->getName() == Name) {
+    Found = true;
+    return false;
+  }
+  return true;
+}
+
+/// \brief Forward any declaration references to the actual check on the
+/// referenced declaration.
+bool DeclFinderASTVisitor::VisitDeclRefExpr(DeclRefExpr *DeclRef) {
+  if (auto *D = dyn_cast<NamedDecl>(DeclRef->getDecl()))
+    return VisitNamedDecl(D);
+  return true;
+}
+
+/// \brief If the new variable name conflicts with any type used in the loop,
+/// then we mark that variable name as taken.
+bool DeclFinderASTVisitor::VisitTypeLoc(TypeLoc TL) {
+  QualType QType = TL.getType();
+
+  // Check if our name conflicts with a type, to handle for typedefs.
+  if (QType.getAsString() == Name) {
+    Found = true;
+    return false;
+  }
+  // Check for base type conflicts. For example, when a struct is being
+  // referenced in the body of the loop, the above getAsString() will return the
+  // whole type (ex. "struct s"), but will be caught here.
+  if (const IdentifierInfo *Ident = QType.getBaseTypeIdentifier()) {
+    if (Ident->getName() == Name) {
+      Found = true;
+      return false;
+    }
+  }
+  return true;
+}
+
+/// \brief Look through conversion/copy constructors to find the explicit
+/// initialization expression, returning it is found.
+///
+/// The main idea is that given
+///   vector<int> v;
+/// we consider either of these initializations
+///   vector<int>::iterator it = v.begin();
+///   vector<int>::iterator it(v.begin());
+/// and retrieve `v.begin()` as the expression used to initialize `it` but do
+/// not include
+///   vector<int>::iterator it;
+///   vector<int>::iterator it(v.begin(), 0); // if this constructor existed
+/// as being initialized from `v.begin()`
+const Expr *digThroughConstructors(const Expr *E) {
+  if (!E)
+    return nullptr;
+  E = E->IgnoreParenImpCasts();
+  if (const auto *ConstructExpr = dyn_cast<CXXConstructExpr>(E)) {
+    // The initial constructor must take exactly one parameter, but base class
+    // and deferred constructors can take more.
+    if (ConstructExpr->getNumArgs() != 1 ||
+        ConstructExpr->getConstructionKind() != CXXConstructExpr::CK_Complete)
+      return nullptr;
+    E = ConstructExpr->getArg(0);
+    if (const auto *Temp = dyn_cast<MaterializeTemporaryExpr>(E))
+      E = Temp->GetTemporaryExpr();
+    return digThroughConstructors(E);
+  }
+  return E;
+}
+
+/// \brief Returns true when two Exprs are equivalent.
+bool areSameExpr(ASTContext *Context, const Expr *First, const Expr *Second) {
+  if (!First || !Second)
+    return false;
+
+  llvm::FoldingSetNodeID FirstID, SecondID;
+  First->Profile(FirstID, *Context, true);
+  Second->Profile(SecondID, *Context, true);
+  return FirstID == SecondID;
+}
+
+/// \brief Returns the DeclRefExpr represented by E, or NULL if there isn't one.
+const DeclRefExpr *getDeclRef(const Expr *E) {
+  return dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
+}
+
+/// \brief Returns true when two ValueDecls are the same variable.
+bool areSameVariable(const ValueDecl *First, const ValueDecl *Second) {
+  return First && Second &&
+         First->getCanonicalDecl() == Second->getCanonicalDecl();
+}
+
+/// \brief Determines if an expression is a declaration reference to a
+/// particular variable.
+static bool exprReferencesVariable(const ValueDecl *Target, const Expr *E) {
+  if (!Target || !E)
+    return false;
+  const DeclRefExpr *Decl = getDeclRef(E);
+  return Decl && areSameVariable(Target, Decl->getDecl());
+}
+
+/// \brief If the expression is a dereference or call to operator*(), return the
+/// operand. Otherwise, return NULL.
+static const Expr *getDereferenceOperand(const Expr *E) {
+  if (const auto *Uop = dyn_cast<UnaryOperator>(E))
+    return Uop->getOpcode() == UO_Deref ? Uop->getSubExpr() : nullptr;
+
+  if (const auto *OpCall = dyn_cast<CXXOperatorCallExpr>(E)) {
+    return OpCall->getOperator() == OO_Star && OpCall->getNumArgs() == 1
+               ? OpCall->getArg(0)
+               : nullptr;
+  }
+
+  return nullptr;
+}
+
+/// \brief Returns true when the Container contains an Expr equivalent to E.
+template <typename ContainerT>
+static bool containsExpr(ASTContext *Context, const ContainerT *Container,
+                         const Expr *E) {
+  llvm::FoldingSetNodeID ID;
+  E->Profile(ID, *Context, true);
+  for (const auto &I : *Container) {
+    if (ID == I.second)
+      return true;
+  }
+  return false;
+}
+
+/// \brief Returns true when the index expression is a declaration reference to
+/// IndexVar.
+///
+/// If the index variable is `index`, this function returns true on
+///    arrayExpression[index];
+///    containerExpression[index];
+/// but not
+///    containerExpression[notIndex];
+static bool isIndexInSubscriptExpr(const Expr *IndexExpr,
+                                   const VarDecl *IndexVar) {
+  const DeclRefExpr *Idx = getDeclRef(IndexExpr);
+  return Idx && Idx->getType()->isIntegerType() &&
+         areSameVariable(IndexVar, Idx->getDecl());
+}
+
+/// \brief Returns true when the index expression is a declaration reference to
+/// IndexVar, Obj is the same expression as SourceExpr after all parens and
+/// implicit casts are stripped off.
+///
+/// If PermitDeref is true, IndexExpression may
+/// be a dereference (overloaded or builtin operator*).
+///
+/// This function is intended for array-like containers, as it makes sure that
+/// both the container and the index match.
+/// If the loop has index variable `index` and iterates over `container`, then
+/// isIndexInSubscriptExpr returns true for
+/// \code
+///   container[index]
+///   container.at(index)
+///   container->at(index)
+/// \endcode
+/// but not for
+/// \code
+///   container[notIndex]
+///   notContainer[index]
+/// \endcode
+/// If PermitDeref is true, then isIndexInSubscriptExpr additionally returns
+/// true on these expressions:
+/// \code
+///   (*container)[index]
+///   (*container).at(index)
+/// \endcode
+static bool isIndexInSubscriptExpr(ASTContext *Context, const Expr *IndexExpr,
+                                   const VarDecl *IndexVar, const Expr *Obj,
+                                   const Expr *SourceExpr, bool PermitDeref) {
+  if (!SourceExpr || !Obj || !isIndexInSubscriptExpr(IndexExpr, IndexVar))
+    return false;
+
+  if (areSameExpr(Context, SourceExpr->IgnoreParenImpCasts(),
+                  Obj->IgnoreParenImpCasts()))
+    return true;
+
+  if (const Expr *InnerObj = getDereferenceOperand(Obj->IgnoreParenImpCasts()))
+    if (PermitDeref && areSameExpr(Context, SourceExpr->IgnoreParenImpCasts(),
+                                   InnerObj->IgnoreParenImpCasts()))
+      return true;
+
+  return false;
+}
+
+/// \brief Returns true when Opcall is a call a one-parameter dereference of
+/// IndexVar.
+///
+/// For example, if the index variable is `index`, returns true for
+///   *index
+/// but not
+///   index
+///   *notIndex
+static bool isDereferenceOfOpCall(const CXXOperatorCallExpr *OpCall,
+                                  const VarDecl *IndexVar) {
+  return OpCall->getOperator() == OO_Star && OpCall->getNumArgs() == 1 &&
+         exprReferencesVariable(IndexVar, OpCall->getArg(0));
+}
+
+/// \brief Returns true when Uop is a dereference of IndexVar.
+///
+/// For example, if the index variable is `index`, returns true for
+///   *index
+/// but not
+///   index
+///   *notIndex
+static bool isDereferenceOfUop(const UnaryOperator *Uop,
+                               const VarDecl *IndexVar) {
+  return Uop->getOpcode() == UO_Deref &&
+         exprReferencesVariable(IndexVar, Uop->getSubExpr());
+}
+
+/// \brief Determines whether the given Decl defines a variable initialized to
+/// the loop object.
+///
+/// This is intended to find cases such as
+/// \code
+///   for (int i = 0; i < arraySize(arr); ++i) {
+///     T t = arr[i];
+///     // use t, do not use i
+///   }
+/// \endcode
+/// and
+/// \code
+///   for (iterator i = container.begin(), e = container.end(); i != e; ++i) {
+///     T t = *i;
+///     // use t, do not use i
+///   }
+/// \endcode
+static bool isAliasDecl(const Decl *TheDecl, const VarDecl *IndexVar) {
+  const auto *VDecl = dyn_cast<VarDecl>(TheDecl);
+  if (!VDecl)
+    return false;
+  if (!VDecl->hasInit())
+    return false;
+
+  const Expr *Init =
+      digThroughConstructors(VDecl->getInit()->IgnoreParenImpCasts());
+  if (!Init)
+    return false;
+
+  switch (Init->getStmtClass()) {
+  case Stmt::ArraySubscriptExprClass: {
+    const auto *E = cast<ArraySubscriptExpr>(Init);
+    // We don't really care which array is used here. We check to make sure
+    // it was the correct one later, since the AST will traverse it next.
+    return isIndexInSubscriptExpr(E->getIdx(), IndexVar);
+  }
+
+  case Stmt::UnaryOperatorClass:
+    return isDereferenceOfUop(cast<UnaryOperator>(Init), IndexVar);
+
+  case Stmt::CXXOperatorCallExprClass: {
+    const auto *OpCall = cast<CXXOperatorCallExpr>(Init);
+    if (OpCall->getOperator() == OO_Star)
+      return isDereferenceOfOpCall(OpCall, IndexVar);
+    if (OpCall->getOperator() == OO_Subscript) {
+      assert(OpCall->getNumArgs() == 2);
+      return true;
+    }
+    break;
+  }
+
+  case Stmt::CXXMemberCallExprClass:
+    return true;
+
+  default:
+    break;
+  }
+  return false;
+}
+
+/// \brief Determines whether the bound of a for loop condition expression is
+/// the same as the statically computable size of ArrayType.
+///
+/// Given
+/// \code
+///   const int N = 5;
+///   int arr[N];
+/// \endcode
+/// This is intended to permit
+/// \code
+///   for (int i = 0; i < N; ++i) {  /* use arr[i] */ }
+///   for (int i = 0; i < arraysize(arr); ++i) { /* use arr[i] */ }
+/// \endcode
+static bool arrayMatchesBoundExpr(ASTContext *Context,
+                                  const QualType &ArrayType,
+                                  const Expr *ConditionExpr) {
+  if (!ConditionExpr || ConditionExpr->isValueDependent())
+    return false;
+  const ConstantArrayType *ConstType =
+      Context->getAsConstantArrayType(ArrayType);
+  if (!ConstType)
+    return false;
+  llvm::APSInt ConditionSize;
+  if (!ConditionExpr->isIntegerConstantExpr(ConditionSize, *Context))
+    return false;
+  llvm::APSInt ArraySize(ConstType->getSize());
+  return llvm::APSInt::isSameValue(ConditionSize, ArraySize);
+}
+
+ForLoopIndexUseVisitor::ForLoopIndexUseVisitor(ASTContext *Context,
+                                               const VarDecl *IndexVar,
+                                               const VarDecl *EndVar,
+                                               const Expr *ContainerExpr,
+                                               const Expr *ArrayBoundExpr,
+                                               bool ContainerNeedsDereference)
+    : Context(Context), IndexVar(IndexVar), EndVar(EndVar),
+      ContainerExpr(ContainerExpr), ArrayBoundExpr(ArrayBoundExpr),
+      ContainerNeedsDereference(ContainerNeedsDereference),
+      OnlyUsedAsIndex(true), AliasDecl(nullptr),
+      ConfidenceLevel(Confidence::CL_Safe), NextStmtParent(nullptr),
+      CurrStmtParent(nullptr), ReplaceWithAliasUse(false),
+      AliasFromForInit(false) {
+  if (ContainerExpr) {
+    addComponent(ContainerExpr);
+    FoldingSetNodeID ID;
+    const Expr *E = ContainerExpr->IgnoreParenImpCasts();
+    E->Profile(ID, *Context, true);
+  }
+}
+
+bool ForLoopIndexUseVisitor::findAndVerifyUsages(const Stmt *Body) {
+  TraverseStmt(const_cast<Stmt *>(Body));
+  return OnlyUsedAsIndex && ContainerExpr;
+}
+
+void ForLoopIndexUseVisitor::addComponents(const ComponentVector &Components) {
+  // FIXME: add sort(on ID)+unique to avoid extra work.
+  for (const auto &I : Components)
+    addComponent(I);
+}
+
+void ForLoopIndexUseVisitor::addComponent(const Expr *E) {
+  FoldingSetNodeID ID;
+  const Expr *Node = E->IgnoreParenImpCasts();
+  Node->Profile(ID, *Context, true);
+  DependentExprs.push_back(std::make_pair(Node, ID));
+}
+
+/// \brief If the unary operator is a dereference of IndexVar, include it
+/// as a valid usage and prune the traversal.
+///
+/// For example, if container.begin() and container.end() both return pointers
+/// to int, this makes sure that the initialization for `k` is not counted as an
+/// unconvertible use of the iterator `i`.
+/// \code
+///   for (int *i = container.begin(), *e = container.end(); i != e; ++i) {
+///     int k = *i + 2;
+///   }
+/// \endcode
+bool ForLoopIndexUseVisitor::TraverseUnaryDeref(UnaryOperator *Uop) {
+  // If we dereference an iterator that's actually a pointer, count the
+  // occurrence.
+  if (isDereferenceOfUop(Uop, IndexVar)) {
+    Usages.push_back(Usage(Uop));
+    return true;
+  }
+
+  return VisitorBase::TraverseUnaryOperator(Uop);
+}
+
+/// \brief If the member expression is operator-> (overloaded or not) on
+/// IndexVar, include it as a valid usage and prune the traversal.
+///
+/// For example, given
+/// \code
+///   struct Foo { int bar(); int x; };
+///   vector<Foo> v;
+/// \endcode
+/// the following uses will be considered convertible:
+/// \code
+///   for (vector<Foo>::iterator i = v.begin(), e = v.end(); i != e; ++i) {
+///     int b = i->bar();
+///     int k = i->x + 1;
+///   }
+/// \endcode
+/// though
+/// \code
+///   for (vector<Foo>::iterator i = v.begin(), e = v.end(); i != e; ++i) {
+///     int k = i.insert(1);
+///   }
+///   for (vector<Foo>::iterator i = v.begin(), e = v.end(); i != e; ++i) {
+///     int b = e->bar();
+///   }
+/// \endcode
+/// will not.
+bool ForLoopIndexUseVisitor::TraverseMemberExpr(MemberExpr *Member) {
+  const Expr *Base = Member->getBase();
+  const DeclRefExpr *Obj = getDeclRef(Base);
+  const Expr *ResultExpr = Member;
+  QualType ExprType;
+  if (const auto *Call =
+          dyn_cast<CXXOperatorCallExpr>(Base->IgnoreParenImpCasts())) {
+    // If operator->() is a MemberExpr containing a CXXOperatorCallExpr, then
+    // the MemberExpr does not have the expression we want. We therefore catch
+    // that instance here.
+    // For example, if vector<Foo>::iterator defines operator->(), then the
+    // example `i->bar()` at the top of this function is a CXXMemberCallExpr
+    // referring to `i->` as the member function called. We want just `i`, so
+    // we take the argument to operator->() as the base object.
+    if (Call->getOperator() == OO_Arrow) {
+      assert(Call->getNumArgs() == 1 &&
+             "Operator-> takes more than one argument");
+      Obj = getDeclRef(Call->getArg(0));
+      ResultExpr = Obj;
+      ExprType = Call->getCallReturnType(*Context);
+    }
+  }
+
+  if (Member->isArrow() && Obj && exprReferencesVariable(IndexVar, Obj)) {
+    if (ExprType.isNull())
+      ExprType = Obj->getType();
+
+    assert(ExprType->isPointerType() && "Operator-> returned non-pointer type");
+    // FIXME: This works around not having the location of the arrow operator.
+    // Consider adding OperatorLoc to MemberExpr?
+    SourceLocation ArrowLoc = Lexer::getLocForEndOfToken(
+        Base->getExprLoc(), 0, Context->getSourceManager(),
+        Context->getLangOpts());
+    // If something complicated is happening (i.e. the next token isn't an
+    // arrow), give up on making this work.
+    if (!ArrowLoc.isInvalid()) {
+      Usages.push_back(Usage(ResultExpr, /*IsArrow=*/true,
+                             SourceRange(Base->getExprLoc(), ArrowLoc)));
+      return true;
+    }
+  }
+  return TraverseStmt(Member->getBase());
+}
+
+/// \brief If a member function call is the at() accessor on the container with
+/// IndexVar as the single argument, include it as a valid usage and prune
+/// the traversal.
+///
+/// Member calls on other objects will not be permitted.
+/// Calls on the iterator object are not permitted, unless done through
+/// operator->(). The one exception is allowing vector::at() for pseudoarrays.
+bool ForLoopIndexUseVisitor::TraverseCXXMemberCallExpr(
+    CXXMemberCallExpr *MemberCall) {
+  auto *Member =
+      dyn_cast<MemberExpr>(MemberCall->getCallee()->IgnoreParenImpCasts());
+  if (!Member)
+    return VisitorBase::TraverseCXXMemberCallExpr(MemberCall);
+
+  // We specifically allow an accessor named "at" to let STL in, though
+  // this is restricted to pseudo-arrays by requiring a single, integer
+  // argument.
+  const IdentifierInfo *Ident = Member->getMemberDecl()->getIdentifier();
+  if (Ident && Ident->isStr("at") && MemberCall->getNumArgs() == 1) {
+    if (isIndexInSubscriptExpr(Context, MemberCall->getArg(0), IndexVar,
+                               Member->getBase(), ContainerExpr,
+                               ContainerNeedsDereference)) {
+      Usages.push_back(Usage(MemberCall));
+      return true;
+    }
+  }
+
+  if (containsExpr(Context, &DependentExprs, Member->getBase()))
+    ConfidenceLevel.lowerTo(Confidence::CL_Risky);
+
+  return VisitorBase::TraverseCXXMemberCallExpr(MemberCall);
+}
+
+/// \brief If an overloaded operator call is a dereference of IndexVar or
+/// a subscript of a the container with IndexVar as the single argument,
+/// include it as a valid usage and prune the traversal.
+///
+/// For example, given
+/// \code
+///   struct Foo { int bar(); int x; };
+///   vector<Foo> v;
+///   void f(Foo);
+/// \endcode
+/// the following uses will be considered convertible:
+/// \code
+///   for (vector<Foo>::iterator i = v.begin(), e = v.end(); i != e; ++i) {
+///     f(*i);
+///   }
+///   for (int i = 0; i < v.size(); ++i) {
+///      int i = v[i] + 1;
+///   }
+/// \endcode
+bool ForLoopIndexUseVisitor::TraverseCXXOperatorCallExpr(
+    CXXOperatorCallExpr *OpCall) {
+  switch (OpCall->getOperator()) {
+  case OO_Star:
+    if (isDereferenceOfOpCall(OpCall, IndexVar)) {
+      Usages.push_back(Usage(OpCall));
+      return true;
+    }
+    break;
+
+  case OO_Subscript:
+    if (OpCall->getNumArgs() != 2)
+      break;
+    if (isIndexInSubscriptExpr(Context, OpCall->getArg(1), IndexVar,
+                               OpCall->getArg(0), ContainerExpr,
+                               ContainerNeedsDereference)) {
+      Usages.push_back(Usage(OpCall));
+      return true;
+    }
+    break;
+
+  default:
+    break;
+  }
+  return VisitorBase::TraverseCXXOperatorCallExpr(OpCall);
+}
+
+/// \brief If we encounter an array with IndexVar as the index of an
+/// ArraySubsriptExpression, note it as a consistent usage and prune the
+/// AST traversal.
+///
+/// For example, given
+/// \code
+///   const int N = 5;
+///   int arr[N];
+/// \endcode
+/// This is intended to permit
+/// \code
+///   for (int i = 0; i < N; ++i) {  /* use arr[i] */ }
+/// \endcode
+/// but not
+/// \code
+///   for (int i = 0; i < N; ++i) {  /* use notArr[i] */ }
+/// \endcode
+/// and further checking needs to be done later to ensure that exactly one array
+/// is referenced.
+bool ForLoopIndexUseVisitor::TraverseArraySubscriptExpr(ArraySubscriptExpr *E) {
+  Expr *Arr = E->getBase();
+  if (!isIndexInSubscriptExpr(E->getIdx(), IndexVar))
+    return VisitorBase::TraverseArraySubscriptExpr(E);
+
+  if ((ContainerExpr &&
+       !areSameExpr(Context, Arr->IgnoreParenImpCasts(),
+                    ContainerExpr->IgnoreParenImpCasts())) ||
+      !arrayMatchesBoundExpr(Context, Arr->IgnoreImpCasts()->getType(),
+                             ArrayBoundExpr)) {
+    // If we have already discovered the array being indexed and this isn't it
+    // or this array doesn't match, mark this loop as unconvertible.
+    OnlyUsedAsIndex = false;
+    return VisitorBase::TraverseArraySubscriptExpr(E);
+  }
+
+  if (!ContainerExpr)
+    ContainerExpr = Arr;
+
+  Usages.push_back(Usage(E));
+  return true;
+}
+
+/// \brief If we encounter a reference to IndexVar in an unpruned branch of the
+/// traversal, mark this loop as unconvertible.
+///
+/// This implements the whitelist for convertible loops: any usages of IndexVar
+/// not explicitly considered convertible by this traversal will be caught by
+/// this function.
+///
+/// Additionally, if the container expression is more complex than just a
+/// DeclRefExpr, and some part of it is appears elsewhere in the loop, lower
+/// our confidence in the transformation.
+///
+/// For example, these are not permitted:
+/// \code
+///   for (int i = 0; i < N; ++i) {  printf("arr[%d] = %d", i, arr[i]); }
+///   for (vector<int>::iterator i = container.begin(), e = container.end();
+///        i != e; ++i)
+///     i.insert(0);
+///   for (vector<int>::iterator i = container.begin(), e = container.end();
+///        i != e; ++i)
+///     i.insert(0);
+///   for (vector<int>::iterator i = container.begin(), e = container.end();
+///        i != e; ++i)
+///     if (i + 1 != e)
+///       printf("%d", *i);
+/// \endcode
+///
+/// And these will raise the risk level:
+/// \code
+///    int arr[10][20];
+///    int l = 5;
+///    for (int j = 0; j < 20; ++j)
+///      int k = arr[l][j] + l; // using l outside arr[l] is considered risky
+///    for (int i = 0; i < obj.getVector().size(); ++i)
+///      obj.foo(10); // using `obj` is considered risky
+/// \endcode
+bool ForLoopIndexUseVisitor::VisitDeclRefExpr(DeclRefExpr *E) {
+  const ValueDecl *TheDecl = E->getDecl();
+  if (areSameVariable(IndexVar, TheDecl) || areSameVariable(EndVar, TheDecl))
+    OnlyUsedAsIndex = false;
+  if (containsExpr(Context, &DependentExprs, E))
+    ConfidenceLevel.lowerTo(Confidence::CL_Risky);
+  return true;
+}
+
+/// \brief If we find that another variable is created just to refer to the loop
+/// element, note it for reuse as the loop variable.
+///
+/// See the comments for isAliasDecl.
+bool ForLoopIndexUseVisitor::VisitDeclStmt(DeclStmt *S) {
+  if (!AliasDecl && S->isSingleDecl() &&
+      isAliasDecl(S->getSingleDecl(), IndexVar)) {
+    AliasDecl = S;
+    if (CurrStmtParent) {
+      if (isa<IfStmt>(CurrStmtParent) || isa<WhileStmt>(CurrStmtParent) ||
+          isa<SwitchStmt>(CurrStmtParent))
+        ReplaceWithAliasUse = true;
+      else if (isa<ForStmt>(CurrStmtParent)) {
+        if (cast<ForStmt>(CurrStmtParent)->getConditionVariableDeclStmt() == S)
+          ReplaceWithAliasUse = true;
+        else
+          // It's assumed S came the for loop's init clause.
+          AliasFromForInit = true;
+      }
+    }
+  }
+
+  return true;
+}
+
+bool ForLoopIndexUseVisitor::TraverseStmt(Stmt *S) {
+  // All this pointer swapping is a mechanism for tracking immediate parentage
+  // of Stmts.
+  const Stmt *OldNextParent = NextStmtParent;
+  CurrStmtParent = NextStmtParent;
+  NextStmtParent = S;
+  bool Result = VisitorBase::TraverseStmt(S);
+  NextStmtParent = OldNextParent;
+  return Result;
+}
+
+std::string VariableNamer::createIndexName() {
+  // FIXME: Add in naming conventions to handle:
+  //  - Uppercase/lowercase indices.
+  //  - How to handle conflicts.
+  //  - An interactive process for naming.
+  std::string IteratorName;
+  std::string ContainerName;
+  if (TheContainer)
+    ContainerName = TheContainer->getName().str();
+
+  size_t Len = ContainerName.length();
+  if (Len > 1 && ContainerName[Len - 1] == 's')
+    IteratorName = ContainerName.substr(0, Len - 1);
+  else
+    IteratorName = "elem";
+
+  if (!declarationExists(IteratorName))
+    return IteratorName;
+
+  IteratorName = ContainerName + "_" + OldIndex->getName().str();
+  if (!declarationExists(IteratorName))
+    return IteratorName;
+
+  IteratorName = ContainerName + "_elem";
+  if (!declarationExists(IteratorName))
+    return IteratorName;
+
+  IteratorName += "_elem";
+  if (!declarationExists(IteratorName))
+    return IteratorName;
+
+  IteratorName = "_elem_";
+
+  // Someone defeated my naming scheme...
+  while (declarationExists(IteratorName))
+    IteratorName += "i";
+  return IteratorName;
+}
+
+/// \brief Determines whether or not the the name \a Symbol conflicts with
+/// language keywords or defined macros. Also checks if the name exists in
+/// LoopContext, any of its parent contexts, or any of its child statements.
+///
+/// We also check to see if the same identifier was generated by this loop
+/// converter in a loop nested within SourceStmt.
+bool VariableNamer::declarationExists(StringRef Symbol) {
+  assert(Context != nullptr && "Expected an ASTContext");
+  IdentifierInfo &Ident = Context->Idents.get(Symbol);
+
+  // Check if the symbol is not an identifier (ie. is a keyword or alias).
+  if (!isAnyIdentifier(Ident.getTokenID()))
+    return true;
+
+  // Check for conflicting macro definitions.
+  if (Ident.hasMacroDefinition())
+    return true;
+
+  // Determine if the symbol was generated in a parent context.
+  for (const Stmt *S = SourceStmt; S != nullptr; S = ReverseAST->lookup(S)) {
+    StmtGeneratedVarNameMap::const_iterator I = GeneratedDecls->find(S);
+    if (I != GeneratedDecls->end() && I->second == Symbol)
+      return true;
+  }
+
+  // FIXME: Rather than detecting conflicts at their usages, we should check the
+  // parent context.
+  // For some reason, lookup() always returns the pair (NULL, NULL) because its
+  // StoredDeclsMap is not initialized (i.e. LookupPtr.getInt() is false inside
+  // of DeclContext::lookup()). Why is this?
+
+  // Finally, determine if the symbol was used in the loop or a child context.
+  DeclFinderASTVisitor DeclFinder(Symbol, GeneratedDecls);
+  return DeclFinder.findUsages(SourceStmt);
+}
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang

Added: clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.h
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.h?rev=245427&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.h (added)
+++ clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertUtils.h Wed Aug 19 04:11:46 2015
@@ -0,0 +1,420 @@
+//===--- LoopConvertUtils.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_LOOP_CONVERT_UTILS_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_LOOP_CONVERT_UTILS_H
+
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Tooling/Refactoring.h"
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+enum LoopFixerKind { LFK_Array, LFK_Iterator, LFK_PseudoArray };
+
+/// A map used to walk the AST in reverse: maps child Stmt to parent Stmt.
+typedef llvm::DenseMap<const clang::Stmt *, const clang::Stmt *> StmtParentMap;
+
+/// A map used to walk the AST in reverse:
+///  maps VarDecl to the to parent DeclStmt.
+typedef llvm::DenseMap<const clang::VarDecl *, const clang::DeclStmt *>
+    DeclParentMap;
+
+/// A map used to track which variables have been removed by a refactoring pass.
+/// It maps the parent ForStmt to the removed index variable's VarDecl.
+typedef llvm::DenseMap<const clang::ForStmt *, const clang::VarDecl *>
+    ReplacedVarsMap;
+
+/// A map used to remember the variable names generated in a Stmt
+typedef llvm::DenseMap<const clang::Stmt *, std::string>
+    StmtGeneratedVarNameMap;
+
+/// A vector used to store the AST subtrees of an Expr.
+typedef llvm::SmallVector<const clang::Expr *, 16> ComponentVector;
+
+/// \brief Class used build the reverse AST properties needed to detect
+/// name conflicts and free variables.
+class StmtAncestorASTVisitor
+    : public clang::RecursiveASTVisitor<StmtAncestorASTVisitor> {
+public:
+  StmtAncestorASTVisitor() { StmtStack.push_back(nullptr); }
+
+  /// \brief Run the analysis on the TranslationUnitDecl.
+  ///
+  /// In case we're running this analysis multiple times, don't repeat the work.
+  void gatherAncestors(const clang::TranslationUnitDecl *T) {
+    if (StmtAncestors.empty())
+      TraverseDecl(const_cast<clang::TranslationUnitDecl *>(T));
+  }
+
+  /// Accessor for StmtAncestors.
+  const StmtParentMap &getStmtToParentStmtMap() { return StmtAncestors; }
+
+  /// Accessor for DeclParents.
+  const DeclParentMap &getDeclToParentStmtMap() { return DeclParents; }
+
+  friend class clang::RecursiveASTVisitor<StmtAncestorASTVisitor>;
+
+private:
+  StmtParentMap StmtAncestors;
+  DeclParentMap DeclParents;
+  llvm::SmallVector<const clang::Stmt *, 16> StmtStack;
+
+  bool TraverseStmt(clang::Stmt *Statement);
+  bool VisitDeclStmt(clang::DeclStmt *Statement);
+};
+
+/// Class used to find the variables and member expressions on which an
+/// arbitrary expression depends.
+class ComponentFinderASTVisitor
+    : public clang::RecursiveASTVisitor<ComponentFinderASTVisitor> {
+public:
+  ComponentFinderASTVisitor() {}
+
+  /// Find the components of an expression and place them in a ComponentVector.
+  void findExprComponents(const clang::Expr *SourceExpr) {
+    TraverseStmt(const_cast<clang::Expr *>(SourceExpr));
+  }
+
+  /// Accessor for Components.
+  const ComponentVector &getComponents() { return Components; }
+
+  friend class clang::RecursiveASTVisitor<ComponentFinderASTVisitor>;
+
+private:
+  ComponentVector Components;
+
+  bool VisitDeclRefExpr(clang::DeclRefExpr *E);
+  bool VisitMemberExpr(clang::MemberExpr *Member);
+};
+
+/// Class used to determine if an expression is dependent on a variable declared
+/// inside of the loop where it would be used.
+class DependencyFinderASTVisitor
+    : public clang::RecursiveASTVisitor<DependencyFinderASTVisitor> {
+public:
+  DependencyFinderASTVisitor(const StmtParentMap *StmtParents,
+                             const DeclParentMap *DeclParents,
+                             const ReplacedVarsMap *ReplacedVars,
+                             const clang::Stmt *ContainingStmt)
+      : StmtParents(StmtParents), DeclParents(DeclParents),
+        ContainingStmt(ContainingStmt), ReplacedVars(ReplacedVars) {}
+
+  /// \brief Run the analysis on Body, and return true iff the expression
+  /// depends on some variable declared within ContainingStmt.
+  ///
+  /// This is intended to protect against hoisting the container expression
+  /// outside of an inner context if part of that expression is declared in that
+  /// inner context.
+  ///
+  /// For example,
+  /// \code
+  ///   const int N = 10, M = 20;
+  ///   int arr[N][M];
+  ///   int getRow();
+  ///
+  ///   for (int i = 0; i < M; ++i) {
+  ///     int k = getRow();
+  ///     printf("%d:", arr[k][i]);
+  ///   }
+  /// \endcode
+  /// At first glance, this loop looks like it could be changed to
+  /// \code
+  ///   for (int elem : arr[k]) {
+  ///     int k = getIndex();
+  ///     printf("%d:", elem);
+  ///   }
+  /// \endcode
+  /// But this is malformed, since `k` is used before it is defined!
+  ///
+  /// In order to avoid this, this class looks at the container expression
+  /// `arr[k]` and decides whether or not it contains a sub-expression declared
+  /// within the the loop body.
+  bool dependsOnInsideVariable(const clang::Stmt *Body) {
+    DependsOnInsideVariable = false;
+    TraverseStmt(const_cast<clang::Stmt *>(Body));
+    return DependsOnInsideVariable;
+  }
+
+  friend class clang::RecursiveASTVisitor<DependencyFinderASTVisitor>;
+
+private:
+  const StmtParentMap *StmtParents;
+  const DeclParentMap *DeclParents;
+  const clang::Stmt *ContainingStmt;
+  const ReplacedVarsMap *ReplacedVars;
+  bool DependsOnInsideVariable;
+
+  bool VisitVarDecl(clang::VarDecl *V);
+  bool VisitDeclRefExpr(clang::DeclRefExpr *D);
+};
+
+/// Class used to determine if any declarations used in a Stmt would conflict
+/// with a particular identifier. This search includes the names that don't
+/// actually appear in the AST (i.e. created by a refactoring tool) by including
+/// a map from Stmts to generated names associated with those stmts.
+class DeclFinderASTVisitor
+    : public clang::RecursiveASTVisitor<DeclFinderASTVisitor> {
+public:
+  DeclFinderASTVisitor(const std::string &Name,
+                       const StmtGeneratedVarNameMap *GeneratedDecls)
+      : Name(Name), GeneratedDecls(GeneratedDecls), Found(false) {}
+
+  /// Attempts to find any usages of variables name Name in Body, returning
+  /// true when it is used in Body. This includes the generated loop variables
+  /// of ForStmts which have already been transformed.
+  bool findUsages(const clang::Stmt *Body) {
+    Found = false;
+    TraverseStmt(const_cast<clang::Stmt *>(Body));
+    return Found;
+  }
+
+  friend class clang::RecursiveASTVisitor<DeclFinderASTVisitor>;
+
+private:
+  std::string Name;
+  /// GeneratedDecls keeps track of ForStmts which have been transformed,
+  /// mapping each modified ForStmt to the variable generated in the loop.
+  const StmtGeneratedVarNameMap *GeneratedDecls;
+  bool Found;
+
+  bool VisitForStmt(clang::ForStmt *F);
+  bool VisitNamedDecl(clang::NamedDecl *D);
+  bool VisitDeclRefExpr(clang::DeclRefExpr *D);
+  bool VisitTypeLoc(clang::TypeLoc TL);
+};
+
+/// \brief The information needed to describe a valid convertible usage
+/// of an array index or iterator.
+struct Usage {
+  const Expr *E;
+  bool IsArrow;
+  SourceRange Range;
+
+  explicit Usage(const Expr *E)
+      : E(E), IsArrow(false), Range(E->getSourceRange()) {}
+  Usage(const Expr *E, bool IsArrow, SourceRange Range)
+      : E(E), IsArrow(IsArrow), Range(std::move(Range)) {}
+};
+
+/// \brief A class to encapsulate lowering of the tool's confidence level.
+class Confidence {
+public:
+  enum Level {
+    // Transformations that are likely to change semantics.
+    CL_Risky,
+
+    // Transformations that might change semantics.
+    CL_Reasonable,
+
+    // Transformations that will not change semantics.
+    CL_Safe
+  };
+  /// \brief Initialize confidence level.
+  explicit Confidence(Confidence::Level Level) : CurrentLevel(Level) {}
+
+  /// \brief Lower the internal confidence level to Level, but do not raise it.
+  void lowerTo(Confidence::Level Level) {
+    CurrentLevel = std::min(Level, CurrentLevel);
+  }
+
+  /// \brief Return the internal confidence level.
+  Level getLevel() const { return CurrentLevel; }
+
+private:
+  Level CurrentLevel;
+};
+
+// The main computational result of ForLoopIndexVisitor.
+typedef llvm::SmallVector<Usage, 8> UsageResult;
+
+// General functions used by ForLoopIndexUseVisitor and LoopConvertCheck.
+const Expr *digThroughConstructors(const Expr *E);
+bool areSameExpr(ASTContext *Context, const Expr *First, const Expr *Second);
+const DeclRefExpr *getDeclRef(const Expr *E);
+bool areSameVariable(const ValueDecl *First, const ValueDecl *Second);
+
+/// \brief Discover usages of expressions consisting of index or iterator
+/// access.
+///
+/// Given an index variable, recursively crawls a for loop to discover if the
+/// index variable is used in a way consistent with range-based for loop access.
+class ForLoopIndexUseVisitor
+    : public RecursiveASTVisitor<ForLoopIndexUseVisitor> {
+public:
+  ForLoopIndexUseVisitor(ASTContext *Context, const VarDecl *IndexVar,
+                         const VarDecl *EndVar, const Expr *ContainerExpr,
+                         const Expr *ArrayBoundExpr,
+                         bool ContainerNeedsDereference);
+
+  /// \brief Finds all uses of IndexVar in Body, placing all usages in Usages,
+  /// and returns true if IndexVar was only used in a way consistent with a
+  /// range-based for loop.
+  ///
+  /// The general strategy is to reject any DeclRefExprs referencing IndexVar,
+  /// with the exception of certain acceptable patterns.
+  /// For arrays, the DeclRefExpr for IndexVar must appear as the index of an
+  /// ArraySubscriptExpression. Iterator-based loops may dereference
+  /// IndexVar or call methods through operator-> (builtin or overloaded).
+  /// Array-like containers may use IndexVar as a parameter to the at() member
+  /// function and in overloaded operator[].
+  bool findAndVerifyUsages(const Stmt *Body);
+
+  /// \brief Add a set of components that we should consider relevant to the
+  /// container.
+  void addComponents(const ComponentVector &Components);
+
+  /// \brief Accessor for Usages.
+  const UsageResult &getUsages() const { return Usages; }
+
+  /// \brief Get the container indexed by IndexVar, if any.
+  const Expr *getContainerIndexed() const { return ContainerExpr; }
+
+  /// \brief Returns the statement declaring the variable created as an alias
+  /// for the loop element, if any.
+  const DeclStmt *getAliasDecl() const { return AliasDecl; }
+
+  /// \brief Accessor for ConfidenceLevel.
+  Confidence::Level getConfidenceLevel() const {
+    return ConfidenceLevel.getLevel();
+  }
+
+  /// \brief Indicates if the alias declaration was in a place where it cannot
+  /// simply be removed but rather replaced with a use of the alias variable.
+  /// For example, variables declared in the condition of an if, switch, or for
+  /// stmt.
+  bool aliasUseRequired() const { return ReplaceWithAliasUse; }
+
+  /// \brief Indicates if the alias declaration came from the init clause of a
+  /// nested for loop. SourceRanges provided by Clang for DeclStmts in this
+  /// case need to be adjusted.
+  bool aliasFromForInit() const { return AliasFromForInit; }
+
+private:
+  /// Typedef used in CRTP functions.
+  typedef RecursiveASTVisitor<ForLoopIndexUseVisitor> VisitorBase;
+  friend class RecursiveASTVisitor<ForLoopIndexUseVisitor>;
+
+  /// Overriden methods for RecursiveASTVisitor's traversal.
+  bool TraverseArraySubscriptExpr(ArraySubscriptExpr *E);
+  bool TraverseCXXMemberCallExpr(CXXMemberCallExpr *MemberCall);
+  bool TraverseCXXOperatorCallExpr(CXXOperatorCallExpr *OpCall);
+  bool TraverseMemberExpr(MemberExpr *Member);
+  bool TraverseUnaryDeref(UnaryOperator *Uop);
+  bool VisitDeclRefExpr(DeclRefExpr *E);
+  bool VisitDeclStmt(DeclStmt *S);
+  bool TraverseStmt(Stmt *S);
+
+  /// \brief Add an expression to the list of expressions on which the container
+  /// expression depends.
+  void addComponent(const Expr *E);
+
+  // Input member variables:
+  ASTContext *Context;
+  /// The index variable's VarDecl.
+  const VarDecl *IndexVar;
+  /// The loop's 'end' variable, which cannot be mentioned at all.
+  const VarDecl *EndVar;
+  /// The Expr which refers to the container.
+  const Expr *ContainerExpr;
+  /// The Expr which refers to the terminating condition for array-based loops.
+  const Expr *ArrayBoundExpr;
+  bool ContainerNeedsDereference;
+
+  // Output member variables:
+  /// A container which holds all usages of IndexVar as the index of
+  /// ArraySubscriptExpressions.
+  UsageResult Usages;
+  bool OnlyUsedAsIndex;
+  /// The DeclStmt for an alias to the container element.
+  const DeclStmt *AliasDecl;
+  Confidence ConfidenceLevel;
+  /// \brief A list of expressions on which ContainerExpr depends.
+  ///
+  /// If any of these expressions are encountered outside of an acceptable usage
+  /// of the loop element, lower our confidence level.
+  llvm::SmallVector<std::pair<const Expr *, llvm::FoldingSetNodeID>, 16>
+      DependentExprs;
+
+  /// The parent-in-waiting. Will become the real parent once we traverse down
+  /// one level in the AST.
+  const Stmt *NextStmtParent;
+  /// The actual parent of a node when Visit*() calls are made. Only the
+  /// parentage of DeclStmt's to possible iteration/selection statements is of
+  /// importance.
+  const Stmt *CurrStmtParent;
+
+  /// \see aliasUseRequired().
+  bool ReplaceWithAliasUse;
+  /// \see aliasFromForInit().
+  bool AliasFromForInit;
+};
+
+struct TUTrackingInfo {
+  /// \brief Reset and initialize per-TU tracking information.
+  ///
+  /// Must be called before using container accessors.
+  TUTrackingInfo() : ParentFinder(new StmtAncestorASTVisitor) {}
+
+  StmtAncestorASTVisitor &getParentFinder() { return *ParentFinder; }
+  StmtGeneratedVarNameMap &getGeneratedDecls() { return GeneratedDecls; }
+  ReplacedVarsMap &getReplacedVars() { return ReplacedVars; }
+
+private:
+  std::unique_ptr<StmtAncestorASTVisitor> ParentFinder;
+  StmtGeneratedVarNameMap GeneratedDecls;
+  ReplacedVarsMap ReplacedVars;
+};
+
+/// \brief Create names for generated variables within a particular statement.
+///
+/// VariableNamer uses a DeclContext as a reference point, checking for any
+/// conflicting declarations higher up in the context or within SourceStmt.
+/// It creates a variable name using hints from a source container and the old
+/// index, if they exist.
+class VariableNamer {
+public:
+  VariableNamer(StmtGeneratedVarNameMap *GeneratedDecls,
+                const StmtParentMap *ReverseAST, const clang::Stmt *SourceStmt,
+                const clang::VarDecl *OldIndex,
+                const clang::VarDecl *TheContainer,
+                const clang::ASTContext *Context)
+      : GeneratedDecls(GeneratedDecls), ReverseAST(ReverseAST),
+        SourceStmt(SourceStmt), OldIndex(OldIndex), TheContainer(TheContainer),
+        Context(Context) {}
+
+  /// \brief Generate a new index name.
+  ///
+  /// Generates the name to be used for an inserted iterator. It relies on
+  /// declarationExists() to determine that there are no naming conflicts, and
+  /// tries to use some hints from the container name and the old index name.
+  std::string createIndexName();
+
+private:
+  StmtGeneratedVarNameMap *GeneratedDecls;
+  const StmtParentMap *ReverseAST;
+  const clang::Stmt *SourceStmt;
+  const clang::VarDecl *OldIndex;
+  const clang::VarDecl *TheContainer;
+  const clang::ASTContext *Context;
+
+  // Determine whether or not a declaration that would conflict with Symbol
+  // exists in an outer context or in any statement contained in SourceStmt.
+  bool declarationExists(llvm::StringRef Symbol);
+};
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_LOOP_CONVERT_UTILS_H

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=245427&r1=245426&r2=245427&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/ModernizeTidyModule.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/modernize/ModernizeTidyModule.cpp Wed Aug 19 04:11:46 2015
@@ -10,6 +10,7 @@
 #include "../ClangTidy.h"
 #include "../ClangTidyModule.h"
 #include "../ClangTidyModuleRegistry.h"
+#include "LoopConvertCheck.h"
 #include "PassByValueCheck.h"
 
 using namespace clang::ast_matchers;
@@ -21,12 +22,14 @@ namespace modernize {
 class ModernizeModule : public ClangTidyModule {
 public:
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
+    CheckFactories.registerCheck<LoopConvertCheck>("modernize-loop-convert");
     CheckFactories.registerCheck<PassByValueCheck>("modernize-pass-by-value");
   }
 
   ClangTidyOptions getModuleOptions() override {
     ClangTidyOptions Options;
     auto &Opts = Options.CheckOptions;
+    Opts["modernize-loop-convert.MinConfidence"] = "reasonable";
     Opts["modernize-pass-by-value.IncludeStyle"] = "llvm"; // Also: "google".
     return Options;
   }

Added: clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/structures.h
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/structures.h?rev=245427&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/structures.h (added)
+++ clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/structures.h Wed Aug 19 04:11:46 2015
@@ -0,0 +1,179 @@
+#ifndef STRUCTURES_H
+#define STRUCTURES_H
+
+extern "C" {
+extern int printf(const char *restrict, ...);
+}
+
+struct Val {int x; void g(); };
+
+struct MutableVal {
+  void constFun(int) const;
+  void nonConstFun(int, int);
+  void constFun(MutableVal &) const;
+  void constParamFun(const MutableVal &) const;
+  void nonConstParamFun(const MutableVal &);
+  int x;
+};
+
+struct S {
+  typedef MutableVal *iterator;
+  typedef const MutableVal *const_iterator;
+  const_iterator begin() const;
+  const_iterator end() const;
+  iterator begin();
+  iterator end();
+};
+
+struct T {
+  struct iterator {
+    int& operator*();
+    const int& operator*()const;
+    iterator& operator ++();
+    bool operator!=(const iterator &other);
+    void insert(int);
+    int x;
+  };
+  iterator begin();
+  iterator end();
+};
+
+struct U {
+  struct iterator {
+    Val& operator*();
+    const Val& operator*()const;
+    iterator& operator ++();
+    bool operator!=(const iterator &other);
+    Val *operator->();
+  };
+  iterator begin();
+  iterator end();
+  int x;
+};
+
+struct X {
+  S s;
+  T t;
+  U u;
+  S getS();
+};
+
+template<typename ElemType>
+class dependent{
+ public:
+  struct iterator_base {
+    const ElemType& operator*()const;
+    iterator_base& operator ++();
+    bool operator!=(const iterator_base &other) const;
+    const ElemType *operator->() const;
+  };
+
+  struct iterator : iterator_base {
+    ElemType& operator*();
+    iterator& operator ++();
+    ElemType *operator->();
+  };
+
+  typedef iterator_base const_iterator;
+  const_iterator begin() const;
+  const_iterator end() const;
+  iterator begin();
+  iterator end();
+  unsigned size() const;
+  ElemType & operator[](unsigned);
+  const ElemType & operator[](unsigned) const;
+  ElemType & at(unsigned);
+  const ElemType & at(unsigned) const;
+
+  // Intentionally evil.
+  dependent<ElemType> operator*();
+
+  void foo();
+  void constFoo() const;
+};
+
+template<typename First, typename Second>
+class doublyDependent{
+ public:
+  struct Value {
+    First first;
+    Second second;
+  };
+
+  struct iterator_base {
+    const Value& operator*()const;
+    iterator_base& operator ++();
+    bool operator!=(const iterator_base &other) const;
+    const Value *operator->() const;
+  };
+
+  struct iterator : iterator_base {
+    Value& operator*();
+    Value& operator ++();
+    Value *operator->();
+  };
+
+  typedef iterator_base const_iterator;
+  const_iterator begin() const;
+  const_iterator end() const;
+  iterator begin();
+  iterator end();
+};
+
+template<typename Contained>
+class transparent {
+ public:
+  Contained *at();
+  Contained *operator->();
+  Contained operator*();
+};
+
+template<typename IteratorType>
+struct Nested {
+  typedef IteratorType* iterator;
+  typedef const IteratorType* const_iterator;
+  IteratorType *operator->();
+  IteratorType operator*();
+  iterator begin();
+  iterator end();
+  const_iterator begin() const;
+  const_iterator end() const;
+};
+
+// Like llvm::SmallPtrSet, the iterator has a dereference operator that returns
+// by value instead of by reference.
+template <typename T>
+struct PtrSet {
+  struct iterator {
+    bool operator!=(const iterator &other) const;
+    const T operator*();
+    iterator &operator++();
+  };
+  iterator begin() const;
+  iterator end() const;
+};
+
+template <typename T>
+struct TypedefDerefContainer {
+  struct iterator {
+    typedef T &deref_type;
+    bool operator!=(const iterator &other) const;
+    deref_type operator*();
+    iterator &operator++();
+  };
+  iterator begin() const;
+  iterator end() const;
+};
+
+template <typename T>
+struct RValueDerefContainer {
+  struct iterator {
+    typedef T &&deref_type;
+    bool operator!=(const iterator &other) const;
+    deref_type operator*();
+    iterator &operator++();
+  };
+  iterator begin() const;
+  iterator end() const;
+};
+#endif  // STRUCTURES_H

Added: clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-basic.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-basic.cpp?rev=245427&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-basic.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-basic.cpp Wed Aug 19 04:11:46 2015
@@ -0,0 +1,548 @@
+// RUN: $(dirname %s)/check_clang_tidy.sh %s modernize-loop-convert %t -- -std=c++11 -I %S/Inputs/modernize-loop-convert
+// REQUIRES: shell
+
+#include "structures.h"
+
+namespace Array {
+
+const int N = 6;
+const int NMinusOne = N - 1;
+int arr[N] = {1, 2, 3, 4, 5, 6};
+int (*pArr)[N] = &arr;
+
+void f() {
+  int sum = 0;
+
+  for (int i = 0; i < N; ++i) {
+    sum += arr[i];
+    int k;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead [modernize-loop-convert]
+  // CHECK-FIXES: for (auto & elem : arr) {
+  // CHECK-FIXES-NEXT: sum += elem;
+  // CHECK-FIXES-NEXT: int k;
+  // CHECK-FIXES-NEXT: }
+
+  for (int i = 0; i < N; ++i) {
+    printf("Fibonacci number is %d\n", arr[i]);
+    sum += arr[i] + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+  // CHECK-FIXES-NEXT: sum += elem + 2;
+
+  for (int i = 0; i < N; ++i) {
+    int x = arr[i];
+    int y = arr[i] + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr)
+  // CHECK-FIXES-NEXT: int x = elem;
+  // CHECK-FIXES-NEXT: int y = elem + 2;
+
+  for (int i = 0; i < N; ++i) {
+    int x = N;
+    x = arr[i];
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr)
+  // CHECK-FIXES-NEXT: int x = N;
+  // CHECK-FIXES-NEXT: x = elem;
+
+  for (int i = 0; i < N; ++i) {
+    arr[i] += 1;
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr) {
+  // CHECK-FIXES-NEXT: elem += 1;
+  // CHECK-FIXES-NEXT: }
+
+  for (int i = 0; i < N; ++i) {
+    int x = arr[i] + 2;
+    arr[i]++;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr)
+  // CHECK-FIXES-NEXT: int x = elem + 2;
+  // CHECK-FIXES-NEXT: elem++;
+
+  for (int i = 0; i < N; ++i) {
+    arr[i] = 4 + arr[i];
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr)
+  // CHECK-FIXES-NEXT: elem = 4 + elem;
+
+  for (int i = 0; i < NMinusOne + 1; ++i) {
+    sum += arr[i];
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr) {
+  // CHECK-FIXES-NEXT: sum += elem;
+  // CHECK-FIXES-NEXT: }
+
+  for (int i = 0; i < N; ++i) {
+    printf("Fibonacci number %d has address %p\n", arr[i], &arr[i]);
+    sum += arr[i] + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number %d has address %p\n", elem, &elem);
+  // CHECK-FIXES-NEXT: sum += elem + 2;
+
+  Val teas[N];
+  for (int i = 0; i < N; ++i) {
+    teas[i].g();
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & tea : teas) {
+  // CHECK-FIXES-NEXT: tea.g();
+  // CHECK-FIXES-NEXT: }
+}
+
+struct HasArr {
+  int Arr[N];
+  Val ValArr[N];
+  void implicitThis() {
+    for (int i = 0; i < N; ++i) {
+      printf("%d", Arr[i]);
+    }
+    // CHECK-MESSAGES: :[[@LINE-3]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : Arr) {
+    // CHECK-FIXES-NEXT: printf("%d", elem);
+    // CHECK-FIXES-NEXT: }
+
+    for (int i = 0; i < N; ++i) {
+      printf("%d", ValArr[i].x);
+    }
+    // CHECK-MESSAGES: :[[@LINE-3]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : ValArr) {
+    // CHECK-FIXES-NEXT: printf("%d", elem.x);
+    // CHECK-FIXES-NEXT: }
+  }
+
+  void explicitThis() {
+    for (int i = 0; i < N; ++i) {
+      printf("%d", this->Arr[i]);
+    }
+    // CHECK-MESSAGES: :[[@LINE-3]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : this->Arr) {
+    // CHECK-FIXES-NEXT: printf("%d", elem);
+    // CHECK-FIXES-NEXT: }
+
+    for (int i = 0; i < N; ++i) {
+      printf("%d", this->ValArr[i].x);
+    }
+    // CHECK-MESSAGES: :[[@LINE-3]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : this->ValArr) {
+    // CHECK-FIXES-NEXT: printf("%d", elem.x);
+    // CHECK-FIXES-NEXT: }
+  }
+};
+
+// Loops whose bounds are value-dependent shold not be converted.
+template <int N>
+void dependentExprBound() {
+  for (int i = 0; i < N; ++i)
+    arr[i] = 0;
+}
+template void dependentExprBound<20>();
+
+void memberFunctionPointer() {
+  Val v;
+  void (Val::*mfpArr[N])(void) = {&Val::g};
+  for (int i = 0; i < N; ++i)
+    (v.*mfpArr[i])();
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : mfpArr)
+  // CHECK-FIXES-NEXT: (v.*elem)();
+}
+
+} // namespace Array
+
+namespace Iterator {
+
+void f() {
+  /// begin()/end() - based for loops here:
+  T t;
+  for (T::iterator it = t.begin(), e = t.end(); it != e; ++it) {
+    printf("I found %d\n", *it);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : t)
+  // CHECK-FIXES-NEXT: printf("I found %d\n", elem);
+
+  T *pt;
+  for (T::iterator it = pt->begin(), e = pt->end(); it != e; ++it) {
+    printf("I found %d\n", *it);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : *pt)
+  // CHECK-FIXES-NEXT: printf("I found %d\n", elem);
+
+  S s;
+  for (S::iterator it = s.begin(), e = s.end(); it != e; ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (elem).x);
+
+  S *ps;
+  for (S::iterator it = ps->begin(), e = ps->end(); it != e; ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & p : *ps)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (p).x);
+
+  for (S::iterator it = s.begin(), e = s.end(); it != e; ++it) {
+    printf("s has value %d\n", it->x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", elem.x);
+
+  for (S::iterator it = s.begin(), e = s.end(); it != e; ++it) {
+    it->x = 3;
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: elem.x = 3;
+
+  for (S::iterator it = s.begin(), e = s.end(); it != e; ++it) {
+    (*it).x = 3;
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: (elem).x = 3;
+
+  for (S::iterator it = s.begin(), e = s.end(); it != e; ++it) {
+    it->nonConstFun(4, 5);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: elem.nonConstFun(4, 5);
+
+  U u;
+  for (U::iterator it = u.begin(), e = u.end(); it != e; ++it) {
+    printf("s has value %d\n", it->x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : u)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", elem.x);
+
+  for (U::iterator it = u.begin(), e = u.end(); it != e; ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : u)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (elem).x);
+
+  U::iterator A;
+  for (U::iterator i = u.begin(), e = u.end(); i != e; ++i)
+    int k = A->x + i->x;
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : u)
+  // CHECK-FIXES-NEXT: int k = A->x + elem.x;
+
+  dependent<int> v;
+  for (dependent<int>::iterator it = v.begin(), e = v.end();
+       it != e; ++it) {
+    printf("Fibonacci number is %d\n", *it);
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : v) {
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+
+  for (dependent<int>::iterator it(v.begin()), e = v.end();
+       it != e; ++it) {
+    printf("Fibonacci number is %d\n", *it);
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : v) {
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+
+  doublyDependent<int, int> intmap;
+  for (doublyDependent<int, int>::iterator it = intmap.begin(), e = intmap.end();
+       it != e; ++it) {
+    printf("intmap[%d] = %d", it->first, it->second);
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : intmap)
+  // CHECK-FIXES: printf("intmap[%d] = %d", elem.first, elem.second);
+
+  // PtrSet's iterator dereferences by value so auto & can't be used.
+  {
+    PtrSet<int *> int_ptrs;
+    for (PtrSet<int *>::iterator I = int_ptrs.begin(),
+                                 E = int_ptrs.end();
+         I != E; ++I) {
+    }
+    // CHECK-MESSAGES: :[[@LINE-4]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto && int_ptr : int_ptrs) {
+  }
+
+  // This container uses an iterator where the derefence type is a typedef of
+  // a reference type. Make sure non-const auto & is still used. A failure here
+  // means canonical types aren't being tested.
+  {
+    TypedefDerefContainer<int> int_ptrs;
+    for (TypedefDerefContainer<int>::iterator I = int_ptrs.begin(),
+                                              E = int_ptrs.end();
+         I != E; ++I) {
+    }
+    // CHECK-MESSAGES: :[[@LINE-4]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & int_ptr : int_ptrs) {
+  }
+
+  {
+    // Iterators returning an rvalue reference should disqualify the loop from
+    // transformation.
+    RValueDerefContainer<int> container;
+    for (RValueDerefContainer<int>::iterator I = container.begin(),
+                                             E = container.end();
+         I != E; ++I) {
+    }
+    // CHECK-FIXES: for (RValueDerefContainer<int>::iterator I = container.begin(),
+    // CHECK-FIXES-NEXT: E = container.end();
+    // CHECK-FIXES-NEXT: I != E; ++I) {
+  }
+}
+
+// Tests to verify the proper use of auto where the init variable type and the
+// initializer type differ or are mostly the same except for const qualifiers.
+void different_type() {
+  // s.begin() returns a type 'iterator' which is just a non-const pointer and
+  // differs from const_iterator only on the const qualification.
+  S s;
+  for (S::const_iterator it = s.begin(), e = s.end(); it != e; ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (const auto & elem : s)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (elem).x);
+
+  S *ps;
+  for (S::const_iterator it = ps->begin(), e = ps->end(); it != e; ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (const auto & p : *ps)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (p).x);
+
+  // v.begin() returns a user-defined type 'iterator' which, since it's
+  // different from const_iterator, disqualifies these loops from
+  // transformation.
+  dependent<int> v;
+  for (dependent<int>::const_iterator it = v.begin(), e = v.end();
+       it != e; ++it) {
+    printf("Fibonacci number is %d\n", *it);
+  }
+  // CHECK-FIXES: for (dependent<int>::const_iterator it = v.begin(), e = v.end();
+  // CHECK-FIXES-NEXT: it != e; ++it) {
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", *it);
+
+  for (dependent<int>::const_iterator it(v.begin()), e = v.end();
+       it != e; ++it) {
+    printf("Fibonacci number is %d\n", *it);
+  }
+  // CHECK-FIXES: for (dependent<int>::const_iterator it(v.begin()), e = v.end();
+  // CHECK-FIXES-NEXT: it != e; ++it) {
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", *it);
+}
+
+// Tests to ensure that an implicit 'this' is picked up as the container.
+// If member calls are made to 'this' within the loop, the transform becomes
+// risky as these calls may affect state that affects the loop.
+class C {
+public:
+  typedef MutableVal *iterator;
+  typedef const MutableVal *const_iterator;
+
+  iterator begin();
+  iterator end();
+  const_iterator begin() const;
+  const_iterator end() const;
+
+  void doSomething();
+  void doSomething() const;
+
+  void doLoop() {
+    for (iterator I = begin(), E = end(); I != E; ++I) {
+    }
+    // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : *this) {
+
+    for (iterator I = C::begin(), E = C::end(); I != E; ++I) {
+    }
+    // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : *this) {
+
+    for (iterator I = begin(), E = end(); I != E; ++I) {
+      doSomething();
+    }
+
+    for (iterator I = begin(); I != end(); ++I) {
+    }
+    // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : *this) {
+
+    for (iterator I = begin(); I != end(); ++I) {
+      doSomething();
+    }
+  }
+
+  void doLoop() const {
+    for (const_iterator I = begin(), E = end(); I != E; ++I) {
+    }
+    // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : *this) {
+
+    for (const_iterator I = C::begin(), E = C::end(); I != E; ++I) {
+    }
+    // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : *this) {
+
+    for (const_iterator I = begin(), E = end(); I != E; ++I) {
+      doSomething();
+    }
+  }
+};
+
+class C2 {
+public:
+  typedef MutableVal *iterator;
+
+  iterator begin() const;
+  iterator end() const;
+
+  void doLoop() {
+    // The implicit 'this' will have an Implicit cast to const C2* wrapped
+    // around it. Make sure the replacement still happens.
+    for (iterator I = begin(), E = end(); I != E; ++I) {
+    }
+    // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use range-based for loop instead
+    // CHECK-FIXES: for (auto & elem : *this) {
+  }
+};
+
+} // namespace Iterator
+
+namespace PseudoArray {
+
+const int N = 6;
+dependent<int> v;
+dependent<int> *pv;
+
+transparent<dependent<int>> cv;
+
+void f() {
+  int sum = 0;
+  for (int i = 0, e = v.size(); i < e; ++i) {
+    printf("Fibonacci number is %d\n", v[i]);
+    sum += v[i] + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : v)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+  // CHECK-FIXES-NEXT: sum += elem + 2;
+
+  for (int i = 0, e = v.size(); i < e; ++i) {
+    printf("Fibonacci number is %d\n", v.at(i));
+    sum += v.at(i) + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : v)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+  // CHECK-FIXES-NEXT: sum += elem + 2;
+
+  for (int i = 0, e = pv->size(); i < e; ++i) {
+    printf("Fibonacci number is %d\n", pv->at(i));
+    sum += pv->at(i) + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : *pv)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+  // CHECK-FIXES-NEXT: sum += elem + 2;
+
+  // This test will fail if size() isn't called repeatedly, since it
+  // returns unsigned int, and 0 is deduced to be signed int.
+  // FIXME: Insert the necessary explicit conversion, or write out the types
+  // explicitly.
+  for (int i = 0; i < pv->size(); ++i) {
+    printf("Fibonacci number is %d\n", (*pv).at(i));
+    sum += (*pv)[i] + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : *pv)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+  // CHECK-FIXES-NEXT: sum += elem + 2;
+
+  for (int i = 0; i < cv->size(); ++i) {
+    printf("Fibonacci number is %d\n", cv->at(i));
+    sum += cv->at(i) + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : *cv)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+  // CHECK-FIXES-NEXT: sum += elem + 2;
+}
+
+// Check for loops that don't mention containers.
+void noContainer() {
+  for (auto i = 0; i < v.size(); ++i) {
+  }
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : v) {
+
+  for (auto i = 0; i < v.size(); ++i)
+    ;
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : v)
+}
+
+struct NoBeginEnd {
+  unsigned size() const;
+};
+
+struct NoConstBeginEnd {
+  NoConstBeginEnd();
+  unsigned size() const;
+  unsigned begin();
+  unsigned end();
+};
+
+struct ConstBeginEnd {
+  ConstBeginEnd();
+  unsigned size() const;
+  unsigned begin() const;
+  unsigned end() const;
+};
+
+// Shouldn't transform pseudo-array uses if the container doesn't provide
+// begin() and end() of the right const-ness.
+void NoBeginEndTest() {
+  NoBeginEnd NBE;
+  for (unsigned i = 0, e = NBE.size(); i < e; ++i) {
+  }
+
+  const NoConstBeginEnd const_NCBE;
+  for (unsigned i = 0, e = const_NCBE.size(); i < e; ++i) {
+  }
+
+  ConstBeginEnd CBE;
+  for (unsigned i = 0, e = CBE.size(); i < e; ++i) {
+  }
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : CBE) {
+
+  const ConstBeginEnd const_CBE;
+  for (unsigned i = 0, e = const_CBE.size(); i < e; ++i) {
+  }
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : const_CBE) {
+}
+
+} // namespace PseudoArray

Added: clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-extra.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-extra.cpp?rev=245427&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-extra.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-extra.cpp Wed Aug 19 04:11:46 2015
@@ -0,0 +1,608 @@
+// RUN: $(dirname %s)/check_clang_tidy.sh %s modernize-loop-convert %t -- -std=c++11 -I %S/Inputs/modernize-loop-convert
+// REQUIRES: shell
+
+#include "structures.h"
+
+namespace Dependency {
+
+void f() {
+  const int N = 6;
+  const int M = 8;
+  int arr[N][M];
+
+  for (int i = 0; i < N; ++i) {
+    int a = 0;
+    int b = arr[i][a];
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : arr) {
+  // CHECK-FIXES-NEXT: int a = 0;
+  // CHECK-FIXES-NEXT: int b = elem[a];
+  // CHECK-FIXES-NEXT: }
+
+  for (int j = 0; j < M; ++j) {
+    int a = 0;
+    int b = arr[a][j];
+  }
+}
+
+} // namespace Dependency
+
+namespace NamingAlias {
+
+const int N = 10;
+
+Val Arr[N];
+dependent<Val> v;
+dependent<Val> *pv;
+Val &func(Val &);
+void sideEffect(int);
+
+void aliasing() {
+  // If the loop container is only used for a declaration of a temporary
+  // variable to hold each element, we can name the new variable for the
+  // converted range-based loop as the temporary variable's name.
+
+  // In the following case, "t" is used as a temporary variable to hold each
+  // element, and thus we consider the name "t" aliased to the loop.
+  // The extra blank braces are left as a placeholder for after the variable
+  // declaration is deleted.
+  for (int i = 0; i < N; ++i) {
+    Val &t = Arr[i];
+    {}
+    int y = t.x;
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & t : Arr)
+  // CHECK-FIXES-NOT: Val &{{[a-z_]+}} =
+  // CHECK-FIXES: {}
+  // CHECK-FIXES-NEXT: int y = t.x;
+
+  // The container was not only used to initialize a temporary loop variable for
+  // the container's elements, so we do not alias the new loop variable.
+  for (int i = 0; i < N; ++i) {
+    Val &t = Arr[i];
+    int y = t.x;
+    int z = Arr[i].x + t.x;
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : Arr)
+  // CHECK-FIXES-NEXT: Val &t = elem;
+  // CHECK-FIXES-NEXT: int y = t.x;
+  // CHECK-FIXES-NEXT: int z = elem.x + t.x;
+
+  for (int i = 0; i < N; ++i) {
+    Val t = Arr[i];
+    int y = t.x;
+    int z = Arr[i].x + t.x;
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : Arr)
+  // CHECK-FIXES-NEXT: Val t = elem;
+  // CHECK-FIXES-NEXT: int y = t.x;
+  // CHECK-FIXES-NEXT: int z = elem.x + t.x;
+
+  // The same for pseudo-arrays like std::vector<T> (or here dependent<Val>)
+  // which provide a subscript operator[].
+  for (int i = 0; i < v.size(); ++i) {
+    Val &t = v[i];
+    {}
+    int y = t.x;
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & t : v)
+  // CHECK-FIXES: {}
+  // CHECK-FIXES-NEXT: int y = t.x;
+
+  // The same with a call to at()
+  for (int i = 0; i < pv->size(); ++i) {
+    Val &t = pv->at(i);
+    {}
+    int y = t.x;
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & t : *pv)
+  // CHECK-FIXES: {}
+  // CHECK-FIXES-NEXT: int y = t.x;
+
+  for (int i = 0; i < N; ++i) {
+    Val &t = func(Arr[i]);
+    int y = t.x;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : Arr)
+  // CHECK-FIXES-NEXT: Val &t = func(elem);
+  // CHECK-FIXES-NEXT: int y = t.x;
+
+  int IntArr[N];
+  for (unsigned i = 0; i < N; ++i) {
+    if (int alias = IntArr[i]) {
+      sideEffect(alias);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto alias : IntArr)
+  // CHECK-FIXES-NEXT: if (alias) {
+
+  for (unsigned i = 0; i < N; ++i) {
+    while (int alias = IntArr[i]) {
+      sideEffect(alias);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto alias : IntArr)
+  // CHECK-FIXES-NEXT: while (alias) {
+
+  for (unsigned i = 0; i < N; ++i) {
+    switch (int alias = IntArr[i]) {
+    default:
+      sideEffect(alias);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-6]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto alias : IntArr)
+  // CHECK-FIXES-NEXT: switch (alias) {
+
+  for (unsigned i = 0; i < N; ++i) {
+    for (int alias = IntArr[i]; alias < N; ++alias) {
+      sideEffect(alias);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto alias : IntArr)
+  // CHECK-FIXES-NEXT: for (; alias < N; ++alias) {
+
+  for (unsigned i = 0; i < N; ++i) {
+    for (unsigned j = 0; int alias = IntArr[i]; ++j) {
+      sideEffect(alias);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto alias : IntArr)
+  // CHECK-FIXES-NEXT: for (unsigned j = 0; alias; ++j) {
+}
+
+void refs_and_vals() {
+  // The following tests check that the transform correctly preserves the
+  // reference or value qualifiers of the aliased variable. That is, if the
+  // variable was declared as a value, the loop variable will be declared as a
+  // value and vice versa for references.
+
+  S s;
+  const S s_const = s;
+
+  for (S::const_iterator it = s_const.begin(); it != s_const.end(); ++it) {
+    MutableVal alias = *it;
+    {}
+    alias.x = 0;
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto alias : s_const)
+  // CHECK-FIXES-NOT: MutableVal {{[a-z_]+}} =
+  // CHECK-FIXES: {}
+  // CHECK-FIXES-NEXT: alias.x = 0;
+
+  for (S::iterator it = s.begin(), e = s.end(); it != e; ++it) {
+    MutableVal alias = *it;
+    {}
+    alias.x = 0;
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto alias : s)
+  // CHECK-FIXES-NOT: MutableVal {{[a-z_]+}} =
+  // CHECK-FIXES: {}
+  // CHECK-FIXES-NEXT: alias.x = 0;
+
+  for (S::iterator it = s.begin(), e = s.end(); it != e; ++it) {
+    MutableVal &alias = *it;
+    {}
+    alias.x = 0;
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & alias : s)
+  // CHECK-FIXES-NOT: MutableVal &{{[a-z_]+}} =
+  // CHECK-FIXES: {}
+  // CHECK-FIXES-NEXT: alias.x = 0;
+}
+
+} // namespace NamingAlias
+
+namespace NamingConlict {
+
+#define MAX(a, b) (a > b) ? a : b
+#define DEF 5
+
+const int N = 10;
+int nums[N];
+int sum = 0;
+
+namespace ns {
+struct st {
+  int x;
+};
+}
+
+void sameNames() {
+  int num = 0;
+  for (int i = 0; i < N; ++i) {
+    printf("Fibonacci number is %d\n", nums[i]);
+    sum += nums[i] + 2 + num;
+    (void)nums[i];
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & nums_i : nums)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", nums_i);
+  // CHECK-FIXES-NEXT: sum += nums_i + 2 + num;
+  // CHECK-FIXES-NOT: (void) num;
+}
+
+void macroConflict() {
+  S MAXs;
+  for (S::iterator it = MAXs.begin(), e = MAXs.end(); it != e; ++it) {
+    printf("s has value %d\n", (*it).x);
+    printf("Max of 3 and 5: %d\n", MAX(3, 5));
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & MAXs_it : MAXs)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (MAXs_it).x);
+  // CHECK-FIXES-NEXT: printf("Max of 3 and 5: %d\n", MAX(3, 5));
+
+  for (S::const_iterator it = MAXs.begin(), e = MAXs.end(); it != e; ++it) {
+    printf("s has value %d\n", (*it).x);
+    printf("Max of 3 and 5: %d\n", MAX(3, 5));
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (const auto & MAXs_it : MAXs)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (MAXs_it).x);
+  // CHECK-FIXES-NEXT: printf("Max of 3 and 5: %d\n", MAX(3, 5));
+
+  T DEFs;
+  for (T::iterator it = DEFs.begin(), e = DEFs.end(); it != e; ++it) {
+    if (*it == DEF) {
+      printf("I found %d\n", *it);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & DEFs_it : DEFs)
+  // CHECK-FIXES-NEXT: if (DEFs_it == DEF) {
+  // CHECK-FIXES-NEXT: printf("I found %d\n", DEFs_it);
+}
+
+void keywordConflict() {
+  T ints;
+  for (T::iterator it = ints.begin(), e = ints.end(); it != e; ++it) {
+    *it = 5;
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & ints_it : ints)
+  // CHECK-FIXES-NEXT: ints_it = 5;
+
+  U __FUNCTION__s;
+  for (U::iterator it = __FUNCTION__s.begin(), e = __FUNCTION__s.end();
+       it != e; ++it) {
+    int __FUNCTION__s_it = (*it).x + 2;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & __FUNCTION__s_elem : __FUNCTION__s)
+  // CHECK-FIXES-NEXT: int __FUNCTION__s_it = (__FUNCTION__s_elem).x + 2;
+}
+
+void typeConflict() {
+  T Vals;
+  // Using the name "Val", although it is the name of an existing struct, is
+  // safe in this loop since it will only exist within this scope.
+  for (T::iterator it = Vals.begin(), e = Vals.end(); it != e; ++it) {
+  }
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & Val : Vals)
+
+  // We cannot use the name "Val" in this loop since there is a reference to
+  // it in the body of the loop.
+  for (T::iterator it = Vals.begin(), e = Vals.end(); it != e; ++it) {
+    *it = sizeof(Val);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & Vals_it : Vals)
+  // CHECK-FIXES-NEXT: Vals_it = sizeof(Val);
+
+  typedef struct Val TD;
+  U TDs;
+  // Naming the variable "TD" within this loop is safe because the typedef
+  // was never used within the loop.
+  for (U::iterator it = TDs.begin(), e = TDs.end(); it != e; ++it) {
+  }
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & TD : TDs)
+
+  // "TD" cannot be used in this loop since the typedef is being used.
+  for (U::iterator it = TDs.begin(), e = TDs.end(); it != e; ++it) {
+    TD V;
+    V.x = 5;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & TDs_it : TDs)
+  // CHECK-FIXES-NEXT: TD V;
+  // CHECK-FIXES-NEXT: V.x = 5;
+
+  using ns::st;
+  T sts;
+  for (T::iterator it = sts.begin(), e = sts.end(); it != e; ++it) {
+    *it = sizeof(st);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & sts_it : sts)
+  // CHECK-FIXES-NEXT: sts_it = sizeof(st);
+}
+
+} // namespace NamingConflict
+
+namespace FreeBeginEnd {
+
+// FIXME: Loop Convert should detect free begin()/end() functions.
+
+struct MyArray {
+  unsigned size();
+};
+
+template <typename T>
+struct MyContainer {
+};
+
+int *begin(const MyArray &Arr);
+int *end(const MyArray &Arr);
+
+template <typename T>
+T *begin(const MyContainer<T> &C);
+template <typename T>
+T *end(const MyContainer<T> &C);
+
+// The Loop Convert Transform doesn't detect free functions begin()/end() and
+// so fails to transform these cases which it should.
+void f() {
+  MyArray Arr;
+  for (unsigned i = 0, e = Arr.size(); i < e; ++i) {
+  }
+
+  MyContainer<int> C;
+  for (int *I = begin(C), *E = end(C); I != E; ++I) {
+  }
+}
+
+} // namespace FreeBeginEnd
+
+namespace Nesting {
+
+void f() {
+  const int N = 10;
+  const int M = 15;
+  Val Arr[N];
+  for (int i = 0; i < N; ++i) {
+    for (int j = 0; j < N; ++j) {
+      int k = Arr[i].x + Arr[j].x;
+      // The repeat is there to allow FileCheck to make sure the two variable
+      // names aren't the same.
+      int l = Arr[i].x + Arr[j].x;
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-8]]:3: warning: use range-based for loop instead
+  // CHECK-MESSAGES: :[[@LINE-8]]:5: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : Arr)
+  // CHECK-FIXES-NEXT: for (auto & Arr_j : Arr)
+  // CHECK-FIXES-NEXT: int k = elem.x + Arr_j.x;
+  // CHECK-FIXES-NOT: int l = elem.x + elem.x;
+
+  // The inner loop is also convertible, but doesn't need to be converted
+  // immediately. FIXME: update this test when that changes.
+  Val Nest[N][M];
+  for (int i = 0; i < N; ++i) {
+    for (int j = 0; j < M; ++j) {
+      printf("Got item %d", Nest[i][j].x);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : Nest)
+  // CHECK-FIXES-NEXT: for (int j = 0; j < M; ++j)
+  // CHECK-FIXES-NEXT: printf("Got item %d", elem[j].x);
+
+  // Note that the order of M and N are switched for this test.
+  for (int j = 0; j < M; ++j) {
+    for (int i = 0; i < N; ++i) {
+      printf("Got item %d", Nest[i][j].x);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:5: warning: use range-based for loop instead
+  // CHECK-FIXES-NOT: for (auto & {{[a-zA-Z_]+}} : Nest[i])
+  // CHECK-FIXES: for (int j = 0; j < M; ++j)
+  // CHECK-FIXES-NEXT: for (auto & elem : Nest)
+  // CHECK-FIXES-NEXT: printf("Got item %d", elem[j].x);
+
+  // The inner loop is also convertible.
+  Nested<T> NestT;
+  for (Nested<T>::iterator I = NestT.begin(), E = NestT.end(); I != E; ++I) {
+    for (T::iterator TI = (*I).begin(), TE = (*I).end(); TI != TE; ++TI) {
+      printf("%d", *TI);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : NestT) {
+  // CHECK-FIXES-NEXT: for (T::iterator TI = (elem).begin(), TE = (elem).end(); TI != TE; ++TI) {
+  // CHECK-FIXES-NEXT: printf("%d", *TI);
+
+  // The inner loop is also convertible.
+  Nested<S> NestS;
+  for (Nested<S>::const_iterator I = NestS.begin(), E = NestS.end(); I != E; ++I) {
+    for (S::const_iterator SI = (*I).begin(), SE = (*I).end(); SI != SE; ++SI) {
+      printf("%d", *SI);
+    }
+  }
+  // CHECK-MESSAGES: :[[@LINE-5]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (const auto & elem : NestS) {
+  // CHECK-FIXES-NEXT: for (S::const_iterator SI = (elem).begin(), SE = (elem).end(); SI != SE; ++SI) {
+  // CHECK-FIXES-NEXT: printf("%d", *SI);
+}
+
+} // namespace Nesting
+
+namespace SingleIterator {
+
+void complexContainer() {
+  X exes[5];
+  int index = 0;
+
+  for (S::iterator i = exes[index].getS().begin(), e = exes[index].getS().end(); i != e; ++i) {
+    MutableVal k = *i;
+    MutableVal j = *i;
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : exes[index].getS())
+  // CHECK-FIXES-NEXT: MutableVal k = elem;
+  // CHECK-FIXES-NEXT: MutableVal j = elem;
+}
+
+void f() {
+  /// begin()/end() - based for loops here:
+  T t;
+  for (T::iterator it = t.begin(); it != t.end(); ++it) {
+    printf("I found %d\n", *it);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : t)
+  // CHECK-FIXES-NEXT: printf("I found %d\n", elem);
+
+  T *pt;
+  for (T::iterator it = pt->begin(); it != pt->end(); ++it) {
+    printf("I found %d\n", *it);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : *pt)
+  // CHECK-FIXES-NEXT: printf("I found %d\n", elem);
+
+  S s;
+  for (S::iterator it = s.begin(); it != s.end(); ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (elem).x);
+
+  S *ps;
+  for (S::iterator it = ps->begin(); it != ps->end(); ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & p : *ps)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (p).x);
+
+  for (S::iterator it = s.begin(); it != s.end(); ++it) {
+    printf("s has value %d\n", it->x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", elem.x);
+
+  for (S::iterator it = s.begin(); it != s.end(); ++it) {
+    it->x = 3;
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: elem.x = 3;
+
+  for (S::iterator it = s.begin(); it != s.end(); ++it) {
+    (*it).x = 3;
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: (elem).x = 3;
+
+  for (S::iterator it = s.begin(); it != s.end(); ++it) {
+    it->nonConstFun(4, 5);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : s)
+  // CHECK-FIXES-NEXT: elem.nonConstFun(4, 5);
+
+  U u;
+  for (U::iterator it = u.begin(); it != u.end(); ++it) {
+    printf("s has value %d\n", it->x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : u)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", elem.x);
+
+  for (U::iterator it = u.begin(); it != u.end(); ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : u)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (elem).x);
+
+  U::iterator A;
+  for (U::iterator i = u.begin(); i != u.end(); ++i)
+    int k = A->x + i->x;
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : u)
+  // CHECK-FIXES-NEXT: int k = A->x + elem.x;
+
+  dependent<int> v;
+  for (dependent<int>::iterator it = v.begin();
+       it != v.end(); ++it) {
+    printf("Fibonacci number is %d\n", *it);
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : v) {
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+
+  for (dependent<int>::iterator it(v.begin());
+       it != v.end(); ++it) {
+    printf("Fibonacci number is %d\n", *it);
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : v) {
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", elem);
+
+  doublyDependent<int, int> intmap;
+  for (doublyDependent<int, int>::iterator it = intmap.begin();
+       it != intmap.end(); ++it) {
+    printf("intmap[%d] = %d", it->first, it->second);
+  }
+  // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : intmap)
+  // CHECK-FIXES-NEXT: printf("intmap[%d] = %d", elem.first, elem.second);
+}
+
+void different_type() {
+  // Tests to verify the proper use of auto where the init variable type and the
+  // initializer type differ or are mostly the same except for const qualifiers.
+
+  // s.begin() returns a type 'iterator' which is just a non-const pointer and
+  // differs from const_iterator only on the const qualification.
+  S s;
+  for (S::const_iterator it = s.begin(); it != s.end(); ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (const auto & elem : s)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (elem).x);
+
+  S *ps;
+  for (S::const_iterator it = ps->begin(); it != ps->end(); ++it) {
+    printf("s has value %d\n", (*it).x);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (const auto & p : *ps)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", (p).x);
+
+  // v.begin() returns a user-defined type 'iterator' which, since it's
+  // different from const_iterator, disqualifies these loops from
+  // transformation.
+  dependent<int> v;
+  for (dependent<int>::const_iterator it = v.begin(); it != v.end(); ++it) {
+    printf("Fibonacci number is %d\n", *it);
+  }
+
+  for (dependent<int>::const_iterator it(v.begin()); it != v.end(); ++it) {
+    printf("Fibonacci number is %d\n", *it);
+  }
+}
+
+}

Added: clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-negative.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-negative.cpp?rev=245427&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-negative.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-negative.cpp Wed Aug 19 04:11:46 2015
@@ -0,0 +1,459 @@
+// RUN: $(dirname %s)/check_clang_tidy.sh %s modernize-loop-convert %t -- -std=c++11 -I %S/Inputs/modernize-loop-convert
+// REQUIRES: shell
+
+#include "structures.h"
+
+// CHECK-FIXES-NOT: for ({{.*[^:]:[^:].*}})
+
+namespace Negative {
+
+const int N = 6;
+int arr[N] = {1, 2, 3, 4, 5, 6};
+int (*pArr)[N] = &arr;
+int sum = 0;
+
+// Checks for the index start and end:
+void indexStartAndEnd() {
+  for (int i = 0; i < N + 1; ++i)
+    sum += arr[i];
+
+  for (int i = 0; i < N - 1; ++i)
+    sum += arr[i];
+
+  for (int i = 1; i < N; ++i)
+    sum += arr[i];
+
+  for (int i = 1; i < N; ++i)
+    sum += arr[i];
+
+  for (int i = 0;; ++i)
+    sum += (*pArr)[i];
+}
+
+// Checks for invalid increment steps:
+void increment() {
+  for (int i = 0; i < N; --i)
+    sum += arr[i];
+
+  for (int i = 0; i < N; i)
+    sum += arr[i];
+
+  for (int i = 0; i < N;)
+    sum += arr[i];
+
+  for (int i = 0; i < N; i += 2)
+    sum++;
+}
+
+// Checks to make sure that the index isn't used outside of the array:
+void indexUse() {
+  for (int i = 0; i < N; ++i)
+    arr[i] += 1 + i;
+}
+
+// Check for loops that don't mention arrays
+void noArray() {
+  for (int i = 0; i < N; ++i)
+    sum += i;
+
+  for (int i = 0; i < N; ++i) {
+  }
+
+  for (int i = 0; i < N; ++i)
+    ;
+}
+
+// Checks for incorrect loop variables.
+void mixedVariables() {
+  int badIndex;
+  for (int i = 0; badIndex < N; ++i)
+    sum += arr[i];
+
+  for (int i = 0; i < N; ++badIndex)
+    sum += arr[i];
+
+  for (int i = 0; badIndex < N; ++badIndex)
+    sum += arr[i];
+
+  for (int i = 0; badIndex < N; ++badIndex)
+    sum += arr[badIndex];
+}
+
+// Checks for multiple arrays indexed.
+void multipleArrays() {
+  int badArr[N];
+
+  for (int i = 0; i < N; ++i)
+    sum += arr[i] + badArr[i];
+
+  for (int i = 0; i < N; ++i) {
+    int k = badArr[i];
+    sum += arr[i] + k;
+  }
+}
+
+struct HasArr {
+  int Arr[N];
+  Val ValArr[N];
+};
+
+struct HasIndirectArr {
+  HasArr HA;
+  void implicitThis() {
+    for (int i = 0; i < N; ++i) {
+      printf("%d", HA.Arr[i]);
+    }
+
+    for (int i = 0; i < N; ++i) {
+      printf("%d", HA.ValArr[i].x);
+    }
+  }
+
+  void explicitThis() {
+    for (int i = 0; i < N; ++i) {
+      printf("%d", this->HA.Arr[i]);
+    }
+
+    for (int i = 0; i < N; ++i) {
+      printf("%d", this->HA.ValArr[i].x);
+    }
+  }
+};
+}
+
+namespace NegativeIterator {
+
+S s;
+T t;
+U u;
+
+struct BadBeginEnd : T {
+  iterator notBegin();
+  iterator notEnd();
+};
+
+void notBeginOrEnd() {
+  BadBeginEnd Bad;
+  for (T::iterator i = Bad.notBegin(), e = Bad.end(); i != e; ++i)
+    int k = *i;
+
+  for (T::iterator i = Bad.begin(), e = Bad.notEnd(); i != e; ++i)
+    int k = *i;
+}
+
+void badLoopShapes() {
+  for (T::iterator i = t.begin(), e = t.end(), f = e; i != e; ++i)
+    int k = *i;
+
+  for (T::iterator i = t.begin(), e = t.end(); i != e;)
+    int k = *i;
+
+  for (T::iterator i = t.begin(), e = t.end();; ++i)
+    int k = *i;
+
+  T::iterator outsideI;
+  T::iterator outsideE;
+
+  for (; outsideI != outsideE; ++outsideI)
+    int k = *outsideI;
+}
+
+void iteratorArrayMix() {
+  int lower;
+  const int N = 6;
+  for (T::iterator i = t.begin(), e = t.end(); lower < N; ++i)
+    int k = *i;
+
+  for (T::iterator i = t.begin(), e = t.end(); lower < N; ++lower)
+    int k = *i;
+}
+
+struct ExtraConstructor : T::iterator {
+  ExtraConstructor(T::iterator, int);
+  explicit ExtraConstructor(T::iterator);
+};
+
+void badConstructor() {
+  for (T::iterator i = ExtraConstructor(t.begin(), 0), e = t.end();
+       i != e; ++i)
+    int k = *i;
+  for (T::iterator i = ExtraConstructor(t.begin()), e = t.end(); i != e; ++i)
+    int k = *i;
+}
+
+void iteratorMemberUsed() {
+  for (T::iterator i = t.begin(), e = t.end(); i != e; ++i)
+    i.x = *i;
+
+  for (T::iterator i = t.begin(), e = t.end(); i != e; ++i)
+    int k = i.x + *i;
+
+  for (T::iterator i = t.begin(), e = t.end(); i != e; ++i)
+    int k = e.x + *i;
+}
+
+void iteratorMethodCalled() {
+  for (T::iterator i = t.begin(), e = t.end(); i != e; ++i)
+    i.insert(3);
+
+  for (T::iterator i = t.begin(), e = t.end(); i != e; ++i)
+    if (i != i)
+      int k = 3;
+}
+
+void iteratorOperatorCalled() {
+  for (T::iterator i = t.begin(), e = t.end(); i != e; ++i)
+    int k = *(++i);
+
+  for (S::iterator i = s.begin(), e = s.end(); i != e; ++i)
+    MutableVal k = *(++i);
+}
+
+void differentContainers() {
+  T other;
+  for (T::iterator i = t.begin(), e = other.end(); i != e; ++i)
+    int k = *i;
+
+  for (T::iterator i = other.begin(), e = t.end(); i != e; ++i)
+    int k = *i;
+
+  S otherS;
+  for (S::iterator i = s.begin(), e = otherS.end(); i != e; ++i)
+    MutableVal k = *i;
+
+  for (S::iterator i = otherS.begin(), e = s.end(); i != e; ++i)
+    MutableVal k = *i;
+}
+
+void wrongIterators() {
+  T::iterator other;
+  for (T::iterator i = t.begin(), e = t.end(); i != other; ++i)
+    int k = *i;
+}
+
+struct EvilArrow : U {
+  // Please, no one ever write code like this.
+  U *operator->();
+};
+
+void differentMemberAccessTypes() {
+  EvilArrow A;
+  for (EvilArrow::iterator i = A.begin(), e = A->end(); i != e; ++i)
+    Val k = *i;
+  for (EvilArrow::iterator i = A->begin(), e = A.end(); i != e; ++i)
+    Val k = *i;
+}
+
+void f(const T::iterator &it, int);
+void f(const T &it, int);
+void g(T &it, int);
+
+void iteratorPassedToFunction() {
+  for (T::iterator i = t.begin(), e = t.end(); i != e; ++i)
+    f(i, *i);
+}
+
+// FIXME: These tests can be removed if this tool ever does enough analysis to
+// decide that this is a safe transformation. Until then, we don't want it
+// applied.
+void iteratorDefinedOutside() {
+  T::iterator theEnd = t.end();
+  for (T::iterator i = t.begin(); i != theEnd; ++i)
+    int k = *i;
+
+  T::iterator theBegin = t.begin();
+  for (T::iterator e = t.end(); theBegin != e; ++theBegin)
+    int k = *theBegin;
+}
+
+} // namespace NegativeIterator
+
+namespace NegativePseudoArray {
+
+const int N = 6;
+dependent<int> v;
+dependent<int> *pv;
+
+transparent<dependent<int>> cv;
+int sum = 0;
+
+// Checks for the index start and end:
+void indexStartAndEnd() {
+  for (int i = 0; i < v.size() + 1; ++i)
+    sum += v[i];
+
+  for (int i = 0; i < v.size() - 1; ++i)
+    sum += v[i];
+
+  for (int i = 1; i < v.size(); ++i)
+    sum += v[i];
+
+  for (int i = 1; i < v.size(); ++i)
+    sum += v[i];
+
+  for (int i = 0;; ++i)
+    sum += (*pv)[i];
+}
+
+// Checks for invalid increment steps:
+void increment() {
+  for (int i = 0; i < v.size(); --i)
+    sum += v[i];
+
+  for (int i = 0; i < v.size(); i)
+    sum += v[i];
+
+  for (int i = 0; i < v.size();)
+    sum += v[i];
+
+  for (int i = 0; i < v.size(); i += 2)
+    sum++;
+}
+
+// Checks to make sure that the index isn't used outside of the container:
+void indexUse() {
+  for (int i = 0; i < v.size(); ++i)
+    v[i] += 1 + i;
+}
+
+// Checks for incorrect loop variables.
+void mixedVariables() {
+  int badIndex;
+  for (int i = 0; badIndex < v.size(); ++i)
+    sum += v[i];
+
+  for (int i = 0; i < v.size(); ++badIndex)
+    sum += v[i];
+
+  for (int i = 0; badIndex < v.size(); ++badIndex)
+    sum += v[i];
+
+  for (int i = 0; badIndex < v.size(); ++badIndex)
+    sum += v[badIndex];
+}
+
+// Checks for an array indexed in addition to the container.
+void multipleArrays() {
+  int badArr[N];
+
+  for (int i = 0; i < v.size(); ++i)
+    sum += v[i] + badArr[i];
+
+  for (int i = 0; i < v.size(); ++i)
+    sum += badArr[i];
+
+  for (int i = 0; i < v.size(); ++i) {
+    int k = badArr[i];
+    sum += k + 2;
+  }
+
+  for (int i = 0; i < v.size(); ++i) {
+    int k = badArr[i];
+    sum += v[i] + k;
+  }
+}
+
+// Checks for multiple containers being indexed container.
+void multipleContainers() {
+  dependent<int> badArr;
+
+  for (int i = 0; i < v.size(); ++i)
+    sum += v[i] + badArr[i];
+
+  for (int i = 0; i < v.size(); ++i)
+    sum += badArr[i];
+
+  for (int i = 0; i < v.size(); ++i) {
+    int k = badArr[i];
+    sum += k + 2;
+  }
+
+  for (int i = 0; i < v.size(); ++i) {
+    int k = badArr[i];
+    sum += v[i] + k;
+  }
+}
+
+// Check to make sure that dereferenced pointers-to-containers behave nicely.
+void derefContainer() {
+  // Note the dependent<T>::operator*() returns another dependent<T>.
+  // This test makes sure that we don't allow an arbitrary number of *'s.
+  for (int i = 0; i < pv->size(); ++i)
+    sum += (**pv).at(i);
+
+  for (int i = 0; i < pv->size(); ++i)
+    sum += (**pv)[i];
+}
+
+void wrongEnd() {
+  int bad;
+  for (int i = 0, e = v.size(); i < bad; ++i)
+    sum += v[i];
+}
+
+// Checks to see that non-const member functions are not called on the container
+// object.
+// These could be conceivably allowed with a lower required confidence level.
+void memberFunctionCalled() {
+  for (int i = 0; i < v.size(); ++i) {
+    sum += v[i];
+    v.foo();
+  }
+
+  for (int i = 0; i < v.size(); ++i) {
+    sum += v[i];
+    dependent<int>::iterator it = v.begin();
+  }
+}
+
+} // namespace NegativePseudoArray
+
+namespace NegativeMultiEndCall {
+
+S s;
+T t;
+U u;
+
+void f(X);
+void f(S);
+void f(T);
+
+void complexContainer() {
+  X x;
+  for (S::iterator i = x.s.begin(), e = x.s.end(); i != e; ++i) {
+    f(x);
+    MutableVal k = *i;
+  }
+
+  for (T::iterator i = x.t.begin(), e = x.t.end(); i != e; ++i) {
+    f(x);
+    int k = *i;
+  }
+
+  for (S::iterator i = x.s.begin(), e = x.s.end(); i != e; ++i) {
+    f(x.s);
+    MutableVal k = *i;
+  }
+
+  for (T::iterator i = x.t.begin(), e = x.t.end(); i != e; ++i) {
+    f(x.t);
+    int k = *i;
+  }
+
+  for (S::iterator i = x.getS().begin(), e = x.getS().end(); i != e; ++i) {
+    f(x.getS());
+    MutableVal k = *i;
+  }
+
+  X exes[5];
+  int index = 0;
+
+  for (S::iterator i = exes[index].getS().begin(),
+                   e = exes[index].getS().end();
+       i != e; ++i) {
+    index++;
+    MutableVal k = *i;
+  }
+}
+
+} // namespace NegativeMultiEndCall




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