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