clang-tools  11.0.0
LoopConvertCheck.cpp
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1 //===--- LoopConvertCheck.cpp - clang-tidy---------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "LoopConvertCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Basic/LLVM.h"
13 #include "clang/Basic/LangOptions.h"
14 #include "clang/Basic/SourceLocation.h"
15 #include "clang/Basic/SourceManager.h"
16 #include "clang/Lex/Lexer.h"
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/StringSwitch.h"
21 #include "llvm/Support/Casting.h"
22 #include <cassert>
23 #include <cstring>
24 #include <utility>
25 
26 using namespace clang::ast_matchers;
27 using namespace llvm;
28 
29 namespace clang {
30 namespace tidy {
31 
32 template <> struct OptionEnumMapping<modernize::Confidence::Level> {
33  static llvm::ArrayRef<std::pair<modernize::Confidence::Level, StringRef>>
35  static constexpr std::pair<modernize::Confidence::Level, StringRef>
36  Mapping[] = {{modernize::Confidence::CL_Reasonable, "reasonable"},
37  {modernize::Confidence::CL_Safe, "safe"},
38  {modernize::Confidence::CL_Risky, "risky"}};
39  return makeArrayRef(Mapping);
40  }
41 };
42 
43 template <> struct OptionEnumMapping<modernize::VariableNamer::NamingStyle> {
44  static llvm::ArrayRef<
45  std::pair<modernize::VariableNamer::NamingStyle, StringRef>>
47  static constexpr std::pair<modernize::VariableNamer::NamingStyle, StringRef>
48  Mapping[] = {{modernize::VariableNamer::NS_CamelCase, "CamelCase"},
49  {modernize::VariableNamer::NS_CamelBack, "camelBack"},
50  {modernize::VariableNamer::NS_LowerCase, "lower_case"},
51  {modernize::VariableNamer::NS_UpperCase, "UPPER_CASE"}};
52  return makeArrayRef(Mapping);
53  }
54 };
55 
56 namespace modernize {
57 
58 static const char LoopNameArray[] = "forLoopArray";
59 static const char LoopNameIterator[] = "forLoopIterator";
60 static const char LoopNamePseudoArray[] = "forLoopPseudoArray";
61 static const char ConditionBoundName[] = "conditionBound";
62 static const char ConditionVarName[] = "conditionVar";
63 static const char IncrementVarName[] = "incrementVar";
64 static const char InitVarName[] = "initVar";
65 static const char BeginCallName[] = "beginCall";
66 static const char EndCallName[] = "endCall";
67 static const char ConditionEndVarName[] = "conditionEndVar";
68 static const char EndVarName[] = "endVar";
69 static const char DerefByValueResultName[] = "derefByValueResult";
70 static const char DerefByRefResultName[] = "derefByRefResult";
71 
72 // shared matchers
73 static const TypeMatcher AnyType() { return anything(); }
74 
75 static const StatementMatcher IntegerComparisonMatcher() {
76  return expr(ignoringParenImpCasts(
77  declRefExpr(to(varDecl(hasType(isInteger())).bind(ConditionVarName)))));
78 }
79 
80 static const DeclarationMatcher InitToZeroMatcher() {
81  return varDecl(
82  hasInitializer(ignoringParenImpCasts(integerLiteral(equals(0)))))
83  .bind(InitVarName);
84 }
85 
86 static const StatementMatcher IncrementVarMatcher() {
87  return declRefExpr(to(varDecl(hasType(isInteger())).bind(IncrementVarName)));
88 }
89 
90 /// The matcher for loops over arrays.
91 ///
92 /// In this general example, assuming 'j' and 'k' are of integral type:
93 /// \code
94 /// for (int i = 0; j < 3 + 2; ++k) { ... }
95 /// \endcode
96 /// The following string identifiers are bound to these parts of the AST:
97 /// ConditionVarName: 'j' (as a VarDecl)
98 /// ConditionBoundName: '3 + 2' (as an Expr)
99 /// InitVarName: 'i' (as a VarDecl)
100 /// IncrementVarName: 'k' (as a VarDecl)
101 /// LoopName: The entire for loop (as a ForStmt)
102 ///
103 /// Client code will need to make sure that:
104 /// - The three index variables identified by the matcher are the same
105 /// VarDecl.
106 /// - The index variable is only used as an array index.
107 /// - All arrays indexed by the loop are the same.
108 StatementMatcher makeArrayLoopMatcher() {
109  StatementMatcher ArrayBoundMatcher =
110  expr(hasType(isInteger())).bind(ConditionBoundName);
111 
112  return forStmt(
113  unless(isInTemplateInstantiation()),
114  hasLoopInit(declStmt(hasSingleDecl(InitToZeroMatcher()))),
115  hasCondition(anyOf(
116  binaryOperator(hasOperatorName("<"),
117  hasLHS(IntegerComparisonMatcher()),
118  hasRHS(ArrayBoundMatcher)),
119  binaryOperator(hasOperatorName(">"), hasLHS(ArrayBoundMatcher),
120  hasRHS(IntegerComparisonMatcher())))),
121  hasIncrement(unaryOperator(hasOperatorName("++"),
122  hasUnaryOperand(IncrementVarMatcher()))))
123  .bind(LoopNameArray);
124 }
125 
126 /// The matcher used for iterator-based for loops.
127 ///
128 /// This matcher is more flexible than array-based loops. It will match
129 /// catch loops of the following textual forms (regardless of whether the
130 /// iterator type is actually a pointer type or a class type):
131 ///
132 /// Assuming f, g, and h are of type containerType::iterator,
133 /// \code
134 /// for (containerType::iterator it = container.begin(),
135 /// e = createIterator(); f != g; ++h) { ... }
136 /// for (containerType::iterator it = container.begin();
137 /// f != anotherContainer.end(); ++h) { ... }
138 /// \endcode
139 /// The following string identifiers are bound to the parts of the AST:
140 /// InitVarName: 'it' (as a VarDecl)
141 /// ConditionVarName: 'f' (as a VarDecl)
142 /// LoopName: The entire for loop (as a ForStmt)
143 /// In the first example only:
144 /// EndVarName: 'e' (as a VarDecl)
145 /// ConditionEndVarName: 'g' (as a VarDecl)
146 /// In the second example only:
147 /// EndCallName: 'container.end()' (as a CXXMemberCallExpr)
148 ///
149 /// Client code will need to make sure that:
150 /// - The iterator variables 'it', 'f', and 'h' are the same.
151 /// - The two containers on which 'begin' and 'end' are called are the same.
152 /// - If the end iterator variable 'g' is defined, it is the same as 'f'.
153 StatementMatcher makeIteratorLoopMatcher() {
154  StatementMatcher BeginCallMatcher =
155  cxxMemberCallExpr(argumentCountIs(0),
156  callee(cxxMethodDecl(hasAnyName("begin", "cbegin"))))
157  .bind(BeginCallName);
158 
159  DeclarationMatcher InitDeclMatcher =
160  varDecl(hasInitializer(anyOf(ignoringParenImpCasts(BeginCallMatcher),
161  materializeTemporaryExpr(
162  ignoringParenImpCasts(BeginCallMatcher)),
163  hasDescendant(BeginCallMatcher))))
164  .bind(InitVarName);
165 
166  DeclarationMatcher EndDeclMatcher =
167  varDecl(hasInitializer(anything())).bind(EndVarName);
168 
169  StatementMatcher EndCallMatcher = cxxMemberCallExpr(
170  argumentCountIs(0), callee(cxxMethodDecl(hasAnyName("end", "cend"))));
171 
172  StatementMatcher IteratorBoundMatcher =
173  expr(anyOf(ignoringParenImpCasts(
174  declRefExpr(to(varDecl().bind(ConditionEndVarName)))),
175  ignoringParenImpCasts(expr(EndCallMatcher).bind(EndCallName)),
176  materializeTemporaryExpr(ignoringParenImpCasts(
177  expr(EndCallMatcher).bind(EndCallName)))));
178 
179  StatementMatcher IteratorComparisonMatcher = expr(
180  ignoringParenImpCasts(declRefExpr(to(varDecl().bind(ConditionVarName)))));
181 
182  auto OverloadedNEQMatcher = ignoringImplicit(
183  cxxOperatorCallExpr(hasOverloadedOperatorName("!="), argumentCountIs(2),
184  hasArgument(0, IteratorComparisonMatcher),
185  hasArgument(1, IteratorBoundMatcher)));
186 
187  // This matcher tests that a declaration is a CXXRecordDecl that has an
188  // overloaded operator*(). If the operator*() returns by value instead of by
189  // reference then the return type is tagged with DerefByValueResultName.
190  internal::Matcher<VarDecl> TestDerefReturnsByValue =
191  hasType(hasUnqualifiedDesugaredType(
192  recordType(hasDeclaration(cxxRecordDecl(hasMethod(cxxMethodDecl(
193  hasOverloadedOperatorName("*"),
194  anyOf(
195  // Tag the return type if it's by value.
196  returns(qualType(unless(hasCanonicalType(referenceType())))
197  .bind(DerefByValueResultName)),
198  returns(
199  // Skip loops where the iterator's operator* returns an
200  // rvalue reference. This is just weird.
201  qualType(unless(hasCanonicalType(rValueReferenceType())))
202  .bind(DerefByRefResultName))))))))));
203 
204  return forStmt(
205  unless(isInTemplateInstantiation()),
206  hasLoopInit(anyOf(declStmt(declCountIs(2),
207  containsDeclaration(0, InitDeclMatcher),
208  containsDeclaration(1, EndDeclMatcher)),
209  declStmt(hasSingleDecl(InitDeclMatcher)))),
210  hasCondition(
211  anyOf(binaryOperator(hasOperatorName("!="),
212  hasLHS(IteratorComparisonMatcher),
213  hasRHS(IteratorBoundMatcher)),
214  binaryOperator(hasOperatorName("!="),
215  hasLHS(IteratorBoundMatcher),
216  hasRHS(IteratorComparisonMatcher)),
217  OverloadedNEQMatcher)),
218  hasIncrement(anyOf(
219  unaryOperator(hasOperatorName("++"),
220  hasUnaryOperand(declRefExpr(
221  to(varDecl(hasType(pointsTo(AnyType())))
222  .bind(IncrementVarName))))),
223  cxxOperatorCallExpr(
224  hasOverloadedOperatorName("++"),
225  hasArgument(
226  0, declRefExpr(to(varDecl(TestDerefReturnsByValue)
227  .bind(IncrementVarName))))))))
228  .bind(LoopNameIterator);
229 }
230 
231 /// The matcher used for array-like containers (pseudoarrays).
232 ///
233 /// This matcher is more flexible than array-based loops. It will match
234 /// loops of the following textual forms (regardless of whether the
235 /// iterator type is actually a pointer type or a class type):
236 ///
237 /// Assuming f, g, and h are of type containerType::iterator,
238 /// \code
239 /// for (int i = 0, j = container.size(); f < g; ++h) { ... }
240 /// for (int i = 0; f < container.size(); ++h) { ... }
241 /// \endcode
242 /// The following string identifiers are bound to the parts of the AST:
243 /// InitVarName: 'i' (as a VarDecl)
244 /// ConditionVarName: 'f' (as a VarDecl)
245 /// LoopName: The entire for loop (as a ForStmt)
246 /// In the first example only:
247 /// EndVarName: 'j' (as a VarDecl)
248 /// ConditionEndVarName: 'g' (as a VarDecl)
249 /// In the second example only:
250 /// EndCallName: 'container.size()' (as a CXXMemberCallExpr)
251 ///
252 /// Client code will need to make sure that:
253 /// - The index variables 'i', 'f', and 'h' are the same.
254 /// - The containers on which 'size()' is called is the container indexed.
255 /// - The index variable is only used in overloaded operator[] or
256 /// container.at().
257 /// - If the end iterator variable 'g' is defined, it is the same as 'j'.
258 /// - The container's iterators would not be invalidated during the loop.
259 StatementMatcher makePseudoArrayLoopMatcher() {
260  // Test that the incoming type has a record declaration that has methods
261  // called 'begin' and 'end'. If the incoming type is const, then make sure
262  // these methods are also marked const.
263  //
264  // FIXME: To be completely thorough this matcher should also ensure the
265  // return type of begin/end is an iterator that dereferences to the same as
266  // what operator[] or at() returns. Such a test isn't likely to fail except
267  // for pathological cases.
268  //
269  // FIXME: Also, a record doesn't necessarily need begin() and end(). Free
270  // functions called begin() and end() taking the container as an argument
271  // are also allowed.
272  TypeMatcher RecordWithBeginEnd = qualType(anyOf(
273  qualType(
274  isConstQualified(),
275  hasUnqualifiedDesugaredType(recordType(hasDeclaration(cxxRecordDecl(
276  hasMethod(cxxMethodDecl(hasName("begin"), isConst())),
277  hasMethod(cxxMethodDecl(hasName("end"),
278  isConst())))) // hasDeclaration
279  ))), // qualType
280  qualType(unless(isConstQualified()),
281  hasUnqualifiedDesugaredType(recordType(hasDeclaration(
282  cxxRecordDecl(hasMethod(hasName("begin")),
283  hasMethod(hasName("end"))))))) // qualType
284  ));
285 
286  StatementMatcher SizeCallMatcher = cxxMemberCallExpr(
287  argumentCountIs(0), callee(cxxMethodDecl(hasAnyName("size", "length"))),
288  on(anyOf(hasType(pointsTo(RecordWithBeginEnd)),
289  hasType(RecordWithBeginEnd))));
290 
291  StatementMatcher EndInitMatcher =
292  expr(anyOf(ignoringParenImpCasts(expr(SizeCallMatcher).bind(EndCallName)),
293  explicitCastExpr(hasSourceExpression(ignoringParenImpCasts(
294  expr(SizeCallMatcher).bind(EndCallName))))));
295 
296  DeclarationMatcher EndDeclMatcher =
297  varDecl(hasInitializer(EndInitMatcher)).bind(EndVarName);
298 
299  StatementMatcher IndexBoundMatcher =
300  expr(anyOf(ignoringParenImpCasts(declRefExpr(to(
301  varDecl(hasType(isInteger())).bind(ConditionEndVarName)))),
302  EndInitMatcher));
303 
304  return forStmt(
305  unless(isInTemplateInstantiation()),
306  hasLoopInit(
307  anyOf(declStmt(declCountIs(2),
308  containsDeclaration(0, InitToZeroMatcher()),
309  containsDeclaration(1, EndDeclMatcher)),
310  declStmt(hasSingleDecl(InitToZeroMatcher())))),
311  hasCondition(anyOf(
312  binaryOperator(hasOperatorName("<"),
313  hasLHS(IntegerComparisonMatcher()),
314  hasRHS(IndexBoundMatcher)),
315  binaryOperator(hasOperatorName(">"), hasLHS(IndexBoundMatcher),
316  hasRHS(IntegerComparisonMatcher())))),
317  hasIncrement(unaryOperator(hasOperatorName("++"),
318  hasUnaryOperand(IncrementVarMatcher()))))
319  .bind(LoopNamePseudoArray);
320 }
321 
322 /// Determine whether Init appears to be an initializing an iterator.
323 ///
324 /// If it is, returns the object whose begin() or end() method is called, and
325 /// the output parameter isArrow is set to indicate whether the initialization
326 /// is called via . or ->.
327 static const Expr *getContainerFromBeginEndCall(const Expr *Init, bool IsBegin,
328  bool *IsArrow) {
329  // FIXME: Maybe allow declaration/initialization outside of the for loop.
330  const auto *TheCall =
331  dyn_cast_or_null<CXXMemberCallExpr>(digThroughConstructors(Init));
332  if (!TheCall || TheCall->getNumArgs() != 0)
333  return nullptr;
334 
335  const auto *Member = dyn_cast<MemberExpr>(TheCall->getCallee());
336  if (!Member)
337  return nullptr;
338  StringRef Name = Member->getMemberDecl()->getName();
339  StringRef TargetName = IsBegin ? "begin" : "end";
340  StringRef ConstTargetName = IsBegin ? "cbegin" : "cend";
341  if (Name != TargetName && Name != ConstTargetName)
342  return nullptr;
343 
344  const Expr *SourceExpr = Member->getBase();
345  if (!SourceExpr)
346  return nullptr;
347 
348  *IsArrow = Member->isArrow();
349  return SourceExpr;
350 }
351 
352 /// Determines the container whose begin() and end() functions are called
353 /// for an iterator-based loop.
354 ///
355 /// BeginExpr must be a member call to a function named "begin()", and EndExpr
356 /// must be a member.
357 static const Expr *findContainer(ASTContext *Context, const Expr *BeginExpr,
358  const Expr *EndExpr,
359  bool *ContainerNeedsDereference) {
360  // Now that we know the loop variable and test expression, make sure they are
361  // valid.
362  bool BeginIsArrow = false;
363  bool EndIsArrow = false;
364  const Expr *BeginContainerExpr =
365  getContainerFromBeginEndCall(BeginExpr, /*IsBegin=*/true, &BeginIsArrow);
366  if (!BeginContainerExpr)
367  return nullptr;
368 
369  const Expr *EndContainerExpr =
370  getContainerFromBeginEndCall(EndExpr, /*IsBegin=*/false, &EndIsArrow);
371  // Disallow loops that try evil things like this (note the dot and arrow):
372  // for (IteratorType It = Obj.begin(), E = Obj->end(); It != E; ++It) { }
373  if (!EndContainerExpr || BeginIsArrow != EndIsArrow ||
374  !areSameExpr(Context, EndContainerExpr, BeginContainerExpr))
375  return nullptr;
376 
377  *ContainerNeedsDereference = BeginIsArrow;
378  return BeginContainerExpr;
379 }
380 
381 /// Obtain the original source code text from a SourceRange.
382 static StringRef getStringFromRange(SourceManager &SourceMgr,
383  const LangOptions &LangOpts,
384  SourceRange Range) {
385  if (SourceMgr.getFileID(Range.getBegin()) !=
386  SourceMgr.getFileID(Range.getEnd())) {
387  return StringRef(); // Empty string.
388  }
389 
390  return Lexer::getSourceText(CharSourceRange(Range, true), SourceMgr,
391  LangOpts);
392 }
393 
394 /// If the given expression is actually a DeclRefExpr or a MemberExpr,
395 /// find and return the underlying ValueDecl; otherwise, return NULL.
396 static const ValueDecl *getReferencedVariable(const Expr *E) {
397  if (const DeclRefExpr *DRE = getDeclRef(E))
398  return dyn_cast<VarDecl>(DRE->getDecl());
399  if (const auto *Mem = dyn_cast<MemberExpr>(E->IgnoreParenImpCasts()))
400  return dyn_cast<FieldDecl>(Mem->getMemberDecl());
401  return nullptr;
402 }
403 
404 /// Returns true when the given expression is a member expression
405 /// whose base is `this` (implicitly or not).
406 static bool isDirectMemberExpr(const Expr *E) {
407  if (const auto *Member = dyn_cast<MemberExpr>(E->IgnoreParenImpCasts()))
408  return isa<CXXThisExpr>(Member->getBase()->IgnoreParenImpCasts());
409  return false;
410 }
411 
412 /// Given an expression that represents an usage of an element from the
413 /// containter that we are iterating over, returns false when it can be
414 /// guaranteed this element cannot be modified as a result of this usage.
415 static bool canBeModified(ASTContext *Context, const Expr *E) {
416  if (E->getType().isConstQualified())
417  return false;
418  auto Parents = Context->getParents(*E);
419  if (Parents.size() != 1)
420  return true;
421  if (const auto *Cast = Parents[0].get<ImplicitCastExpr>()) {
422  if ((Cast->getCastKind() == CK_NoOp &&
423  Cast->getType() == E->getType().withConst()) ||
424  (Cast->getCastKind() == CK_LValueToRValue &&
425  !Cast->getType().isNull() && Cast->getType()->isFundamentalType()))
426  return false;
427  }
428  // FIXME: Make this function more generic.
429  return true;
430 }
431 
432 /// Returns true when it can be guaranteed that the elements of the
433 /// container are not being modified.
434 static bool usagesAreConst(ASTContext *Context, const UsageResult &Usages) {
435  for (const Usage &U : Usages) {
436  // Lambda captures are just redeclarations (VarDecl) of the same variable,
437  // not expressions. If we want to know if a variable that is captured by
438  // reference can be modified in an usage inside the lambda's body, we need
439  // to find the expression corresponding to that particular usage, later in
440  // this loop.
441  if (U.Kind != Usage::UK_CaptureByCopy && U.Kind != Usage::UK_CaptureByRef &&
442  canBeModified(Context, U.Expression))
443  return false;
444  }
445  return true;
446 }
447 
448 /// Returns true if the elements of the container are never accessed
449 /// by reference.
450 static bool usagesReturnRValues(const UsageResult &Usages) {
451  for (const auto &U : Usages) {
452  if (U.Expression && !U.Expression->isRValue())
453  return false;
454  }
455  return true;
456 }
457 
458 /// Returns true if the container is const-qualified.
459 static bool containerIsConst(const Expr *ContainerExpr, bool Dereference) {
460  if (const auto *VDec = getReferencedVariable(ContainerExpr)) {
461  QualType CType = VDec->getType();
462  if (Dereference) {
463  if (!CType->isPointerType())
464  return false;
465  CType = CType->getPointeeType();
466  }
467  // If VDec is a reference to a container, Dereference is false,
468  // but we still need to check the const-ness of the underlying container
469  // type.
470  CType = CType.getNonReferenceType();
471  return CType.isConstQualified();
472  }
473  return false;
474 }
475 
476 LoopConvertCheck::RangeDescriptor::RangeDescriptor()
477  : ContainerNeedsDereference(false), DerefByConstRef(false),
478  DerefByValue(false) {}
479 
480 LoopConvertCheck::LoopConvertCheck(StringRef Name, ClangTidyContext *Context)
481  : ClangTidyCheck(Name, Context), TUInfo(new TUTrackingInfo),
482  MaxCopySize(Options.get("MaxCopySize", 16ULL)),
483  MinConfidence(Options.get("MinConfidence", Confidence::CL_Reasonable)),
484  NamingStyle(Options.get("NamingStyle", VariableNamer::NS_CamelCase)) {}
485 
487  Options.store(Opts, "MaxCopySize", std::to_string(MaxCopySize));
488  Options.store(Opts, "MinConfidence", MinConfidence);
489  Options.store(Opts, "NamingStyle", NamingStyle);
490 }
491 
492 void LoopConvertCheck::registerMatchers(MatchFinder *Finder) {
493  Finder->addMatcher(traverse(ast_type_traits::TK_AsIs, makeArrayLoopMatcher()),
494  this);
495  Finder->addMatcher(
496  traverse(ast_type_traits::TK_AsIs, makeIteratorLoopMatcher()), this);
497  Finder->addMatcher(
498  traverse(ast_type_traits::TK_AsIs, makePseudoArrayLoopMatcher()), this);
499 }
500 
501 /// Given the range of a single declaration, such as:
502 /// \code
503 /// unsigned &ThisIsADeclarationThatCanSpanSeveralLinesOfCode =
504 /// InitializationValues[I];
505 /// next_instruction;
506 /// \endcode
507 /// Finds the range that has to be erased to remove this declaration without
508 /// leaving empty lines, by extending the range until the beginning of the
509 /// next instruction.
510 ///
511 /// We need to delete a potential newline after the deleted alias, as
512 /// clang-format will leave empty lines untouched. For all other formatting we
513 /// rely on clang-format to fix it.
514 void LoopConvertCheck::getAliasRange(SourceManager &SM, SourceRange &Range) {
515  bool Invalid = false;
516  const char *TextAfter =
517  SM.getCharacterData(Range.getEnd().getLocWithOffset(1), &Invalid);
518  if (Invalid)
519  return;
520  unsigned Offset = std::strspn(TextAfter, " \t\r\n");
521  Range =
522  SourceRange(Range.getBegin(), Range.getEnd().getLocWithOffset(Offset));
523 }
524 
525 /// Computes the changes needed to convert a given for loop, and
526 /// applies them.
527 void LoopConvertCheck::doConversion(
528  ASTContext *Context, const VarDecl *IndexVar,
529  const ValueDecl *MaybeContainer, const UsageResult &Usages,
530  const DeclStmt *AliasDecl, bool AliasUseRequired, bool AliasFromForInit,
531  const ForStmt *Loop, RangeDescriptor Descriptor) {
532  std::string VarName;
533  bool VarNameFromAlias = (Usages.size() == 1) && AliasDecl;
534  bool AliasVarIsRef = false;
535  bool CanCopy = true;
536  std::vector<FixItHint> FixIts;
537  if (VarNameFromAlias) {
538  const auto *AliasVar = cast<VarDecl>(AliasDecl->getSingleDecl());
539  VarName = AliasVar->getName().str();
540 
541  // Use the type of the alias if it's not the same
542  QualType AliasVarType = AliasVar->getType();
543  assert(!AliasVarType.isNull() && "Type in VarDecl is null");
544  if (AliasVarType->isReferenceType()) {
545  AliasVarType = AliasVarType.getNonReferenceType();
546  AliasVarIsRef = true;
547  }
548  if (Descriptor.ElemType.isNull() ||
549  !Context->hasSameUnqualifiedType(AliasVarType, Descriptor.ElemType))
550  Descriptor.ElemType = AliasVarType;
551 
552  // We keep along the entire DeclStmt to keep the correct range here.
553  SourceRange ReplaceRange = AliasDecl->getSourceRange();
554 
555  std::string ReplacementText;
556  if (AliasUseRequired) {
557  ReplacementText = VarName;
558  } else if (AliasFromForInit) {
559  // FIXME: Clang includes the location of the ';' but only for DeclStmt's
560  // in a for loop's init clause. Need to put this ';' back while removing
561  // the declaration of the alias variable. This is probably a bug.
562  ReplacementText = ";";
563  } else {
564  // Avoid leaving empty lines or trailing whitespaces.
565  getAliasRange(Context->getSourceManager(), ReplaceRange);
566  }
567 
568  FixIts.push_back(FixItHint::CreateReplacement(
569  CharSourceRange::getTokenRange(ReplaceRange), ReplacementText));
570  // No further replacements are made to the loop, since the iterator or index
571  // was used exactly once - in the initialization of AliasVar.
572  } else {
573  VariableNamer Namer(&TUInfo->getGeneratedDecls(),
574  &TUInfo->getParentFinder().getStmtToParentStmtMap(),
575  Loop, IndexVar, MaybeContainer, Context, NamingStyle);
576  VarName = Namer.createIndexName();
577  // First, replace all usages of the array subscript expression with our new
578  // variable.
579  for (const auto &Usage : Usages) {
580  std::string ReplaceText;
581  SourceRange Range = Usage.Range;
582  if (Usage.Expression) {
583  // If this is an access to a member through the arrow operator, after
584  // the replacement it must be accessed through the '.' operator.
585  ReplaceText = Usage.Kind == Usage::UK_MemberThroughArrow ? VarName + "."
586  : VarName;
587  auto Parents = Context->getParents(*Usage.Expression);
588  if (Parents.size() == 1) {
589  if (const auto *Paren = Parents[0].get<ParenExpr>()) {
590  // Usage.Expression will be replaced with the new index variable,
591  // and parenthesis around a simple DeclRefExpr can always be
592  // removed.
593  Range = Paren->getSourceRange();
594  } else if (const auto *UOP = Parents[0].get<UnaryOperator>()) {
595  // If we are taking the address of the loop variable, then we must
596  // not use a copy, as it would mean taking the address of the loop's
597  // local index instead.
598  // FIXME: This won't catch cases where the address is taken outside
599  // of the loop's body (for instance, in a function that got the
600  // loop's index as a const reference parameter), or where we take
601  // the address of a member (like "&Arr[i].A.B.C").
602  if (UOP->getOpcode() == UO_AddrOf)
603  CanCopy = false;
604  }
605  }
606  } else {
607  // The Usage expression is only null in case of lambda captures (which
608  // are VarDecl). If the index is captured by value, add '&' to capture
609  // by reference instead.
610  ReplaceText =
611  Usage.Kind == Usage::UK_CaptureByCopy ? "&" + VarName : VarName;
612  }
613  TUInfo->getReplacedVars().insert(std::make_pair(Loop, IndexVar));
614  FixIts.push_back(FixItHint::CreateReplacement(
615  CharSourceRange::getTokenRange(Range), ReplaceText));
616  }
617  }
618 
619  // Now, we need to construct the new range expression.
620  SourceRange ParenRange(Loop->getLParenLoc(), Loop->getRParenLoc());
621 
622  QualType Type = Context->getAutoDeductType();
623  if (!Descriptor.ElemType.isNull() && Descriptor.ElemType->isFundamentalType())
624  Type = Descriptor.ElemType.getUnqualifiedType();
625  Type = Type.getDesugaredType(*Context);
626 
627  // If the new variable name is from the aliased variable, then the reference
628  // type for the new variable should only be used if the aliased variable was
629  // declared as a reference.
630  bool IsCheapToCopy =
631  !Descriptor.ElemType.isNull() &&
632  Descriptor.ElemType.isTriviallyCopyableType(*Context) &&
633  // TypeInfo::Width is in bits.
634  Context->getTypeInfo(Descriptor.ElemType).Width <= 8 * MaxCopySize;
635  bool UseCopy = CanCopy && ((VarNameFromAlias && !AliasVarIsRef) ||
636  (Descriptor.DerefByConstRef && IsCheapToCopy));
637 
638  if (!UseCopy) {
639  if (Descriptor.DerefByConstRef) {
640  Type = Context->getLValueReferenceType(Context->getConstType(Type));
641  } else if (Descriptor.DerefByValue) {
642  if (!IsCheapToCopy)
643  Type = Context->getRValueReferenceType(Type);
644  } else {
645  Type = Context->getLValueReferenceType(Type);
646  }
647  }
648 
649  StringRef MaybeDereference = Descriptor.ContainerNeedsDereference ? "*" : "";
650  std::string TypeString = Type.getAsString(getLangOpts());
651  std::string Range = ("(" + TypeString + " " + VarName + " : " +
652  MaybeDereference + Descriptor.ContainerString + ")")
653  .str();
654  FixIts.push_back(FixItHint::CreateReplacement(
655  CharSourceRange::getTokenRange(ParenRange), Range));
656  diag(Loop->getForLoc(), "use range-based for loop instead") << FixIts;
657  TUInfo->getGeneratedDecls().insert(make_pair(Loop, VarName));
658 }
659 
660 /// Returns a string which refers to the container iterated over.
661 StringRef LoopConvertCheck::getContainerString(ASTContext *Context,
662  const ForStmt *Loop,
663  const Expr *ContainerExpr) {
664  StringRef ContainerString;
665  ContainerExpr = ContainerExpr->IgnoreParenImpCasts();
666  if (isa<CXXThisExpr>(ContainerExpr)) {
667  ContainerString = "this";
668  } else {
669  // For CXXOperatorCallExpr (e.g. vector_ptr->size()), its first argument is
670  // the class object (vector_ptr) we are targeting.
671  if (const auto* E = dyn_cast<CXXOperatorCallExpr>(ContainerExpr))
672  ContainerExpr = E->getArg(0);
673  ContainerString =
674  getStringFromRange(Context->getSourceManager(), Context->getLangOpts(),
675  ContainerExpr->getSourceRange());
676  }
677 
678  return ContainerString;
679 }
680 
681 /// Determines what kind of 'auto' must be used after converting a for
682 /// loop that iterates over an array or pseudoarray.
683 void LoopConvertCheck::getArrayLoopQualifiers(ASTContext *Context,
684  const BoundNodes &Nodes,
685  const Expr *ContainerExpr,
686  const UsageResult &Usages,
687  RangeDescriptor &Descriptor) {
688  // On arrays and pseudoarrays, we must figure out the qualifiers from the
689  // usages.
690  if (usagesAreConst(Context, Usages) ||
691  containerIsConst(ContainerExpr, Descriptor.ContainerNeedsDereference)) {
692  Descriptor.DerefByConstRef = true;
693  }
694  if (usagesReturnRValues(Usages)) {
695  // If the index usages (dereference, subscript, at, ...) return rvalues,
696  // then we should not use a reference, because we need to keep the code
697  // correct if it mutates the returned objects.
698  Descriptor.DerefByValue = true;
699  }
700  // Try to find the type of the elements on the container, to check if
701  // they are trivially copyable.
702  for (const Usage &U : Usages) {
703  if (!U.Expression || U.Expression->getType().isNull())
704  continue;
705  QualType Type = U.Expression->getType().getCanonicalType();
706  if (U.Kind == Usage::UK_MemberThroughArrow) {
707  if (!Type->isPointerType()) {
708  continue;
709  }
710  Type = Type->getPointeeType();
711  }
712  Descriptor.ElemType = Type;
713  }
714 }
715 
716 /// Determines what kind of 'auto' must be used after converting an
717 /// iterator based for loop.
718 void LoopConvertCheck::getIteratorLoopQualifiers(ASTContext *Context,
719  const BoundNodes &Nodes,
720  RangeDescriptor &Descriptor) {
721  // The matchers for iterator loops provide bound nodes to obtain this
722  // information.
723  const auto *InitVar = Nodes.getNodeAs<VarDecl>(InitVarName);
724  QualType CanonicalInitVarType = InitVar->getType().getCanonicalType();
725  const auto *DerefByValueType =
726  Nodes.getNodeAs<QualType>(DerefByValueResultName);
727  Descriptor.DerefByValue = DerefByValueType;
728 
729  if (Descriptor.DerefByValue) {
730  // If the dereference operator returns by value then test for the
731  // canonical const qualification of the init variable type.
732  Descriptor.DerefByConstRef = CanonicalInitVarType.isConstQualified();
733  Descriptor.ElemType = *DerefByValueType;
734  } else {
735  if (const auto *DerefType =
736  Nodes.getNodeAs<QualType>(DerefByRefResultName)) {
737  // A node will only be bound with DerefByRefResultName if we're dealing
738  // with a user-defined iterator type. Test the const qualification of
739  // the reference type.
740  auto ValueType = DerefType->getNonReferenceType();
741 
742  Descriptor.DerefByConstRef = ValueType.isConstQualified();
743  Descriptor.ElemType = ValueType;
744  } else {
745  // By nature of the matcher this case is triggered only for built-in
746  // iterator types (i.e. pointers).
747  assert(isa<PointerType>(CanonicalInitVarType) &&
748  "Non-class iterator type is not a pointer type");
749 
750  // We test for const qualification of the pointed-at type.
751  Descriptor.DerefByConstRef =
752  CanonicalInitVarType->getPointeeType().isConstQualified();
753  Descriptor.ElemType = CanonicalInitVarType->getPointeeType();
754  }
755  }
756 }
757 
758 /// Determines the parameters needed to build the range replacement.
759 void LoopConvertCheck::determineRangeDescriptor(
760  ASTContext *Context, const BoundNodes &Nodes, const ForStmt *Loop,
761  LoopFixerKind FixerKind, const Expr *ContainerExpr,
762  const UsageResult &Usages, RangeDescriptor &Descriptor) {
763  Descriptor.ContainerString =
764  std::string(getContainerString(Context, Loop, ContainerExpr));
765 
766  if (FixerKind == LFK_Iterator)
767  getIteratorLoopQualifiers(Context, Nodes, Descriptor);
768  else
769  getArrayLoopQualifiers(Context, Nodes, ContainerExpr, Usages, Descriptor);
770 }
771 
772 /// Check some of the conditions that must be met for the loop to be
773 /// convertible.
774 bool LoopConvertCheck::isConvertible(ASTContext *Context,
775  const ast_matchers::BoundNodes &Nodes,
776  const ForStmt *Loop,
777  LoopFixerKind FixerKind) {
778  // If we already modified the range of this for loop, don't do any further
779  // updates on this iteration.
780  if (TUInfo->getReplacedVars().count(Loop))
781  return false;
782 
783  // Check that we have exactly one index variable and at most one end variable.
784  const auto *LoopVar = Nodes.getNodeAs<VarDecl>(IncrementVarName);
785  const auto *CondVar = Nodes.getNodeAs<VarDecl>(ConditionVarName);
786  const auto *InitVar = Nodes.getNodeAs<VarDecl>(InitVarName);
787  if (!areSameVariable(LoopVar, CondVar) || !areSameVariable(LoopVar, InitVar))
788  return false;
789  const auto *EndVar = Nodes.getNodeAs<VarDecl>(EndVarName);
790  const auto *ConditionEndVar = Nodes.getNodeAs<VarDecl>(ConditionEndVarName);
791  if (EndVar && !areSameVariable(EndVar, ConditionEndVar))
792  return false;
793 
794  // FIXME: Try to put most of this logic inside a matcher.
795  if (FixerKind == LFK_Iterator) {
796  QualType InitVarType = InitVar->getType();
797  QualType CanonicalInitVarType = InitVarType.getCanonicalType();
798 
799  const auto *BeginCall = Nodes.getNodeAs<CXXMemberCallExpr>(BeginCallName);
800  assert(BeginCall && "Bad Callback. No begin call expression");
801  QualType CanonicalBeginType =
802  BeginCall->getMethodDecl()->getReturnType().getCanonicalType();
803  if (CanonicalBeginType->isPointerType() &&
804  CanonicalInitVarType->isPointerType()) {
805  // If the initializer and the variable are both pointers check if the
806  // un-qualified pointee types match, otherwise we don't use auto.
807  if (!Context->hasSameUnqualifiedType(
808  CanonicalBeginType->getPointeeType(),
809  CanonicalInitVarType->getPointeeType()))
810  return false;
811  }
812  } else if (FixerKind == LFK_PseudoArray) {
813  // This call is required to obtain the container.
814  const auto *EndCall = Nodes.getNodeAs<CXXMemberCallExpr>(EndCallName);
815  if (!EndCall || !dyn_cast<MemberExpr>(EndCall->getCallee()))
816  return false;
817  }
818  return true;
819 }
820 
821 void LoopConvertCheck::check(const MatchFinder::MatchResult &Result) {
822  const BoundNodes &Nodes = Result.Nodes;
823  Confidence ConfidenceLevel(Confidence::CL_Safe);
824  ASTContext *Context = Result.Context;
825 
826  const ForStmt *Loop;
827  LoopFixerKind FixerKind;
828  RangeDescriptor Descriptor;
829 
830  if ((Loop = Nodes.getNodeAs<ForStmt>(LoopNameArray))) {
831  FixerKind = LFK_Array;
832  } else if ((Loop = Nodes.getNodeAs<ForStmt>(LoopNameIterator))) {
833  FixerKind = LFK_Iterator;
834  } else {
835  Loop = Nodes.getNodeAs<ForStmt>(LoopNamePseudoArray);
836  assert(Loop && "Bad Callback. No for statement");
837  FixerKind = LFK_PseudoArray;
838  }
839 
840  if (!isConvertible(Context, Nodes, Loop, FixerKind))
841  return;
842 
843  const auto *LoopVar = Nodes.getNodeAs<VarDecl>(IncrementVarName);
844  const auto *EndVar = Nodes.getNodeAs<VarDecl>(EndVarName);
845 
846  // If the loop calls end()/size() after each iteration, lower our confidence
847  // level.
848  if (FixerKind != LFK_Array && !EndVar)
849  ConfidenceLevel.lowerTo(Confidence::CL_Reasonable);
850 
851  // If the end comparison isn't a variable, we can try to work with the
852  // expression the loop variable is being tested against instead.
853  const auto *EndCall = Nodes.getNodeAs<CXXMemberCallExpr>(EndCallName);
854  const auto *BoundExpr = Nodes.getNodeAs<Expr>(ConditionBoundName);
855 
856  // Find container expression of iterators and pseudoarrays, and determine if
857  // this expression needs to be dereferenced to obtain the container.
858  // With array loops, the container is often discovered during the
859  // ForLoopIndexUseVisitor traversal.
860  const Expr *ContainerExpr = nullptr;
861  if (FixerKind == LFK_Iterator) {
862  ContainerExpr = findContainer(Context, LoopVar->getInit(),
863  EndVar ? EndVar->getInit() : EndCall,
864  &Descriptor.ContainerNeedsDereference);
865  } else if (FixerKind == LFK_PseudoArray) {
866  ContainerExpr = EndCall->getImplicitObjectArgument();
867  Descriptor.ContainerNeedsDereference =
868  dyn_cast<MemberExpr>(EndCall->getCallee())->isArrow();
869  }
870 
871  // We must know the container or an array length bound.
872  if (!ContainerExpr && !BoundExpr)
873  return;
874 
875  ForLoopIndexUseVisitor Finder(Context, LoopVar, EndVar, ContainerExpr,
876  BoundExpr,
877  Descriptor.ContainerNeedsDereference);
878 
879  // Find expressions and variables on which the container depends.
880  if (ContainerExpr) {
881  ComponentFinderASTVisitor ComponentFinder;
882  ComponentFinder.findExprComponents(ContainerExpr->IgnoreParenImpCasts());
883  Finder.addComponents(ComponentFinder.getComponents());
884  }
885 
886  // Find usages of the loop index. If they are not used in a convertible way,
887  // stop here.
888  if (!Finder.findAndVerifyUsages(Loop->getBody()))
889  return;
890  ConfidenceLevel.lowerTo(Finder.getConfidenceLevel());
891 
892  // Obtain the container expression, if we don't have it yet.
893  if (FixerKind == LFK_Array) {
894  ContainerExpr = Finder.getContainerIndexed()->IgnoreParenImpCasts();
895 
896  // Very few loops are over expressions that generate arrays rather than
897  // array variables. Consider loops over arrays that aren't just represented
898  // by a variable to be risky conversions.
899  if (!getReferencedVariable(ContainerExpr) &&
900  !isDirectMemberExpr(ContainerExpr))
901  ConfidenceLevel.lowerTo(Confidence::CL_Risky);
902  }
903 
904  // Find out which qualifiers we have to use in the loop range.
905  TraversalKindScope RAII(*Context, ast_type_traits::TK_AsIs);
906  const UsageResult &Usages = Finder.getUsages();
907  determineRangeDescriptor(Context, Nodes, Loop, FixerKind, ContainerExpr,
908  Usages, Descriptor);
909 
910  // Ensure that we do not try to move an expression dependent on a local
911  // variable declared inside the loop outside of it.
912  // FIXME: Determine when the external dependency isn't an expression converted
913  // by another loop.
914  TUInfo->getParentFinder().gatherAncestors(*Context);
915  DependencyFinderASTVisitor DependencyFinder(
916  &TUInfo->getParentFinder().getStmtToParentStmtMap(),
917  &TUInfo->getParentFinder().getDeclToParentStmtMap(),
918  &TUInfo->getReplacedVars(), Loop);
919 
920  if (DependencyFinder.dependsOnInsideVariable(ContainerExpr) ||
921  Descriptor.ContainerString.empty() || Usages.empty() ||
922  ConfidenceLevel.getLevel() < MinConfidence)
923  return;
924 
925  doConversion(Context, LoopVar, getReferencedVariable(ContainerExpr), Usages,
926  Finder.getAliasDecl(), Finder.aliasUseRequired(),
927  Finder.aliasFromForInit(), Loop, Descriptor);
928 }
929 
930 } // namespace modernize
931 } // namespace tidy
932 } // namespace clang
clang::tidy::modernize::makeArrayLoopMatcher
StatementMatcher makeArrayLoopMatcher()
The matcher for loops over arrays.
Definition: LoopConvertCheck.cpp:108
Range
CharSourceRange Range
SourceRange for the file name.
Definition: IncludeOrderCheck.cpp:38
clang::tidy::modernize::DependencyFinderASTVisitor
Class used to determine if an expression is dependent on a variable declared inside of the loop where...
Definition: LoopConvertUtils.h:109
clang::tidy::modernize::usagesReturnRValues
static bool usagesReturnRValues(const UsageResult &Usages)
Returns true if the elements of the container are never accessed by reference.
Definition: LoopConvertCheck.cpp:450
clang::tidy::modernize::getStringFromRange
static StringRef getStringFromRange(SourceManager &SourceMgr, const LangOptions &LangOpts, SourceRange Range)
Obtain the original source code text from a SourceRange.
Definition: LoopConvertCheck.cpp:382
llvm
Some operations such as code completion produce a set of candidates.
Definition: YAMLGenerator.cpp:28
clang::tidy::modernize::Confidence::CL_Reasonable
Definition: LoopConvertUtils.h:249
clang::tidy::modernize::DerefByValueResultName
static const char DerefByValueResultName[]
Definition: LoopConvertCheck.cpp:69
clang::tidy::modernize::areSameVariable
bool areSameVariable(const ValueDecl *First, const ValueDecl *Second)
Returns true when two ValueDecls are the same variable.
Definition: LoopConvertUtils.cpp:203
clang::tidy::modernize::UsageResult
llvm::SmallVector< Usage, 8 > UsageResult
Definition: LoopConvertUtils.h:270
E
const Expr * E
Definition: AvoidBindCheck.cpp:88
Type
NodeType Type
Definition: HTMLGenerator.cpp:73
clang::tidy::modernize::isDirectMemberExpr
static bool isDirectMemberExpr(const Expr *E)
Returns true when the given expression is a member expression whose base is this (implicitly or not).
Definition: LoopConvertCheck.cpp:406
Usage
const char Usage[]
Definition: ClangReorderFields.cpp:50
clang::tidy::modernize::getDeclRef
const DeclRefExpr * getDeclRef(const Expr *E)
Returns the DeclRefExpr represented by E, or NULL if there isn't one.
Definition: LoopConvertUtils.cpp:198
clang::clangd::TypeHierarchyDirection::Parents
clang::tidy::OptionEnumMapping< modernize::Confidence::Level >::getEnumMapping
static llvm::ArrayRef< std::pair< modernize::Confidence::Level, StringRef > > getEnumMapping()
Definition: LoopConvertCheck.cpp:34
clang::tidy::modernize::InitVarName
static const char InitVarName[]
Definition: LoopConvertCheck.cpp:64
clang::tidy::modernize::DerefByRefResultName
static const char DerefByRefResultName[]
Definition: LoopConvertCheck.cpp:70
clang::tidy::modernize::InitToZeroMatcher
static const DeclarationMatcher InitToZeroMatcher()
Definition: LoopConvertCheck.cpp:80
clang::tidy::modernize::Usage::UK_CaptureByCopy
Definition: LoopConvertUtils.h:223
clang::tidy::modernize::makePseudoArrayLoopMatcher
StatementMatcher makePseudoArrayLoopMatcher()
The matcher used for array-like containers (pseudoarrays).
Definition: LoopConvertCheck.cpp:259
clang::tidy::OptionEnumMapping
This class should be specialized by any enum type that needs to be converted to and from an llvm::Str...
Definition: ClangTidyCheck.h:31
clang::tidy::modernize::usagesAreConst
static bool usagesAreConst(ASTContext *Context, const UsageResult &Usages)
Returns true when it can be guaranteed that the elements of the container are not being modified.
Definition: LoopConvertCheck.cpp:434
clang::tidy::ClangTidyCheck
Base class for all clang-tidy checks.
Definition: ClangTidyCheck.h:114
clang::tidy::modernize::Confidence::lowerTo
void lowerTo(Confidence::Level Level)
Lower the internal confidence level to Level, but do not raise it.
Definition: LoopConvertUtils.h:258
clang::tidy::modernize::AnyType
static const TypeMatcher AnyType()
Definition: LoopConvertCheck.cpp:73
clang::tidy::modernize::LoopConvertCheck::check
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
Definition: LoopConvertCheck.cpp:821
clang::tidy::modernize::Usage
The information needed to describe a valid convertible usage of an array index or iterator.
Definition: LoopConvertUtils.h:205
clang::tidy::modernize::canBeModified
static bool canBeModified(ASTContext *Context, const Expr *E)
Given an expression that represents an usage of an element from the containter that we are iterating ...
Definition: LoopConvertCheck.cpp:415
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static const char IncrementVarName[]
Definition: LoopConvertCheck.cpp:63
clang::tidy::modernize::Confidence::CL_Safe
Definition: LoopConvertUtils.h:252
LoopConvertCheck.h
SourceMgr
llvm::SourceMgr * SourceMgr
Definition: ConfigCompile.cpp:72
clang::tidy::modernize::Confidence
A class to encapsulate lowering of the tool's confidence level.
Definition: LoopConvertUtils.h:242
clang::tidy::modernize::EndCallName
static const char EndCallName[]
Definition: LoopConvertCheck.cpp:66
clang::tidy::ClangTidyCheck::getLangOpts
const LangOptions & getLangOpts() const
Returns the language options from the context.
Definition: ClangTidyCheck.h:475
clang::tidy::modernize::ForLoopIndexUseVisitor
Discover usages of expressions consisting of index or iterator access.
Definition: LoopConvertUtils.h:283
clang::tidy::modernize::IntegerComparisonMatcher
static const StatementMatcher IntegerComparisonMatcher()
Definition: LoopConvertCheck.cpp:75
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Definition: AbseilMatcher.h:14
clang::tidy::modernize::EndVarName
static const char EndVarName[]
Definition: LoopConvertCheck.cpp:68
Offset
size_t Offset
Definition: CodeComplete.cpp:1044
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static const ValueDecl * getReferencedVariable(const Expr *E)
If the given expression is actually a DeclRefExpr or a MemberExpr, find and return the underlying Val...
Definition: LoopConvertCheck.cpp:396
clang::tidy::modernize::LoopConvertCheck::storeOptions
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
Definition: LoopConvertCheck.cpp:486
clang::tidy::modernize::containerIsConst
static bool containerIsConst(const Expr *ContainerExpr, bool Dereference)
Returns true if the container is const-qualified.
Definition: LoopConvertCheck.cpp:459
clang::tidy::modernize::ComponentFinderASTVisitor::getComponents
const ComponentVector & getComponents()
Accessor for Components.
Definition: LoopConvertUtils.h:96
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static const char ConditionBoundName[]
Definition: LoopConvertCheck.cpp:61
clang::tidy::ClangTidyCheck::Options
OptionsView Options
Definition: ClangTidyCheck.h:471
clang::tidy::modernize::IncrementVarMatcher
static const StatementMatcher IncrementVarMatcher()
Definition: LoopConvertCheck.cpp:86
clang::tidy::modernize::LoopFixerKind
LoopFixerKind
Definition: LoopConvertUtils.h:29
clang::tidy::ClangTidyContext
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
Definition: ClangTidyDiagnosticConsumer.h:76
clang::tidy::modernize::LoopNameIterator
static const char LoopNameIterator[]
Definition: LoopConvertCheck.cpp:59
Name
static constexpr llvm::StringLiteral Name
Definition: UppercaseLiteralSuffixCheck.cpp:27
clang::tidy::modernize::Usage::UK_MemberThroughArrow
Definition: LoopConvertUtils.h:220
clang::tidy::modernize::TUTrackingInfo
Definition: LoopConvertUtils.h:400
clang::tidy::ClangTidyCheck::diag
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
Definition: ClangTidyCheck.cpp:55
clang::tidy::modernize::LFK_Array
Definition: LoopConvertUtils.h:29
clang::tidy::modernize::ComponentFinderASTVisitor
Class used to find the variables and member expressions on which an arbitrary expression depends.
Definition: LoopConvertUtils.h:85
clang::tidy::modernize::VariableNamer
Create names for generated variables within a particular statement.
Definition: LoopConvertUtils.h:422
clang::tidy::modernize::LoopNamePseudoArray
static const char LoopNamePseudoArray[]
Definition: LoopConvertCheck.cpp:60
clang::tidy::modernize::getContainerFromBeginEndCall
static const Expr * getContainerFromBeginEndCall(const Expr *Init, bool IsBegin, bool *IsArrow)
Determine whether Init appears to be an initializing an iterator.
Definition: LoopConvertCheck.cpp:327
clang::tidy::modernize::Confidence::CL_Risky
Definition: LoopConvertUtils.h:246
clang::tidy::modernize::ConditionEndVarName
static const char ConditionEndVarName[]
Definition: LoopConvertCheck.cpp:67
clang::tidy::modernize::digThroughConstructors
const Expr * digThroughConstructors(const Expr *E)
Look through conversion/copy constructors to find the explicit initialization expression,...
Definition: LoopConvertUtils.cpp:168
clang::tidy::modernize::LoopNameArray
static const char LoopNameArray[]
Definition: LoopConvertCheck.cpp:58
clang::tidy::modernize::LFK_PseudoArray
Definition: LoopConvertUtils.h:29
clang::tidy::modernize::LoopConvertCheck::registerMatchers
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
Definition: LoopConvertCheck.cpp:492
clang::tidy::modernize::ComponentFinderASTVisitor::findExprComponents
void findExprComponents(const clang::Expr *SourceExpr)
Find the components of an expression and place them in a ComponentVector.
Definition: LoopConvertUtils.h:91
clang::tidy::modernize::ConditionVarName
static const char ConditionVarName[]
Definition: LoopConvertCheck.cpp:62
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
clang::tidy::modernize::LFK_Iterator
Definition: LoopConvertUtils.h:29
clang::tidy::modernize::areSameExpr
bool areSameExpr(ASTContext *Context, const Expr *First, const Expr *Second)
Returns true when two Exprs are equivalent.
Definition: LoopConvertUtils.cpp:187
clang::tidy::ClangTidyCheck::OptionsView::store
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, StringRef Value) const
Stores an option with the check-local name LocalName with string value Value to Options.
Definition: ClangTidyCheck.cpp:152
clang::tidy::modernize::BeginCallName
static const char BeginCallName[]
Definition: LoopConvertCheck.cpp:65
clang::tidy::modernize::findContainer
static const Expr * findContainer(ASTContext *Context, const Expr *BeginExpr, const Expr *EndExpr, bool *ContainerNeedsDereference)
Determines the container whose begin() and end() functions are called for an iterator-based loop.
Definition: LoopConvertCheck.cpp:357
clang::tidy::modernize::makeIteratorLoopMatcher
StatementMatcher makeIteratorLoopMatcher()
The matcher used for iterator-based for loops.
Definition: LoopConvertCheck.cpp:153
clang::tidy::modernize::Confidence::getLevel
Level getLevel() const
Return the internal confidence level.
Definition: LoopConvertUtils.h:263
clang::tidy::ClangTidyOptions::OptionMap
std::map< std::string, ClangTidyValue > OptionMap
Definition: ClangTidyOptions.h:111
clang::tidy::OptionEnumMapping< modernize::VariableNamer::NamingStyle >::getEnumMapping
static llvm::ArrayRef< std::pair< modernize::VariableNamer::NamingStyle, StringRef > > getEnumMapping()
Definition: LoopConvertCheck.cpp:46