clang-tools  3.8.0
UniqueptrDeleteReleaseCheck.cpp
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1 //===--- UniqueptrDeleteReleaseCheck.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 
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Lex/Lexer.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace tidy {
19 
20 void UniqueptrDeleteReleaseCheck::registerMatchers(MatchFinder *Finder) {
21  auto IsSusbstituted = qualType(anyOf(
22  substTemplateTypeParmType(), hasDescendant(substTemplateTypeParmType())));
23 
24  auto UniquePtrWithDefaultDelete = classTemplateSpecializationDecl(
25  hasName("std::unique_ptr"),
26  hasTemplateArgument(1, refersToType(qualType(hasDeclaration(cxxRecordDecl(
27  hasName("std::default_delete")))))));
28 
29  Finder->addMatcher(
30  cxxDeleteExpr(
31  has(cxxMemberCallExpr(on(expr(hasType(UniquePtrWithDefaultDelete),
32  unless(hasType(IsSusbstituted)))
33  .bind("uptr")),
34  callee(cxxMethodDecl(hasName("release"))))))
35  .bind("delete"),
36  this);
37 }
38 
39 void UniqueptrDeleteReleaseCheck::check(
40  const MatchFinder::MatchResult &Result) {
41  const auto *PtrExpr = Result.Nodes.getNodeAs<Expr>("uptr");
42  const auto *DeleteExpr = Result.Nodes.getNodeAs<Expr>("delete");
43 
44  if (PtrExpr->getLocStart().isMacroID())
45  return;
46 
47  // Ignore dependent types.
48  // It can give us false positives, so we go with false negatives instead to
49  // be safe.
50  if (PtrExpr->getType()->isDependentType())
51  return;
52 
53  SourceLocation AfterPtr =
54  Lexer::getLocForEndOfToken(PtrExpr->getLocEnd(), 0, *Result.SourceManager,
55  Result.Context->getLangOpts());
56 
57  diag(DeleteExpr->getLocStart(),
58  "prefer '= nullptr' to 'delete x.release()' to reset unique_ptr<> "
59  "objects")
60  << FixItHint::CreateRemoval(CharSourceRange::getCharRange(
61  DeleteExpr->getLocStart(), PtrExpr->getLocStart()))
62  << FixItHint::CreateReplacement(
63  CharSourceRange::getTokenRange(AfterPtr, DeleteExpr->getLocEnd()),
64  " = nullptr");
65 }
66 
67 } // namespace tidy
68 } // namespace clang
69 
std::unique_ptr< ast_matchers::MatchFinder > Finder
Definition: ClangTidy.cpp:188
const NamedDecl * Result
Definition: USRFinder.cpp:121