clang-tools  14.0.0git
MisplacedOperatorInStrlenInAllocCheck.cpp
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1 //===--- MisplacedOperatorInStrlenInAllocCheck.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 
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Lex/Lexer.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace bugprone {
19 
20 void MisplacedOperatorInStrlenInAllocCheck::registerMatchers(
21  MatchFinder *Finder) {
22  const auto StrLenFunc = functionDecl(hasAnyName(
23  "::strlen", "::std::strlen", "::strnlen", "::std::strnlen", "::strnlen_s",
24  "::std::strnlen_s", "::wcslen", "::std::wcslen", "::wcsnlen",
25  "::std::wcsnlen", "::wcsnlen_s", "std::wcsnlen_s"));
26 
27  const auto BadUse =
28  callExpr(callee(StrLenFunc),
29  hasAnyArgument(ignoringImpCasts(
30  binaryOperator(
31  hasOperatorName("+"),
32  hasRHS(ignoringParenImpCasts(integerLiteral(equals(1)))))
33  .bind("BinOp"))))
34  .bind("StrLen");
35 
36  const auto BadArg = anyOf(
37  allOf(unless(binaryOperator(
38  hasOperatorName("+"), hasLHS(BadUse),
39  hasRHS(ignoringParenImpCasts(integerLiteral(equals(1)))))),
40  hasDescendant(BadUse)),
41  BadUse);
42 
43  const auto Alloc0Func = functionDecl(
44  hasAnyName("::malloc", "std::malloc", "::alloca", "std::alloca"));
45  const auto Alloc1Func = functionDecl(
46  hasAnyName("::calloc", "std::calloc", "::realloc", "std::realloc"));
47 
48  const auto Alloc0FuncPtr =
49  varDecl(hasType(isConstQualified()),
50  hasInitializer(ignoringParenImpCasts(
51  declRefExpr(hasDeclaration(Alloc0Func)))));
52  const auto Alloc1FuncPtr =
53  varDecl(hasType(isConstQualified()),
54  hasInitializer(ignoringParenImpCasts(
55  declRefExpr(hasDeclaration(Alloc1Func)))));
56 
57  Finder->addMatcher(
58  traverse(TK_AsIs, callExpr(callee(decl(anyOf(Alloc0Func, Alloc0FuncPtr))),
59  hasArgument(0, BadArg))
60  .bind("Alloc")),
61  this);
62  Finder->addMatcher(
63  traverse(TK_AsIs, callExpr(callee(decl(anyOf(Alloc1Func, Alloc1FuncPtr))),
64  hasArgument(1, BadArg))
65  .bind("Alloc")),
66  this);
67  Finder->addMatcher(
68  traverse(TK_AsIs,
69  cxxNewExpr(isArray(), hasArraySize(BadArg)).bind("Alloc")),
70  this);
71 }
72 
74  const MatchFinder::MatchResult &Result) {
75  const Expr *Alloc = Result.Nodes.getNodeAs<CallExpr>("Alloc");
76  if (!Alloc)
77  Alloc = Result.Nodes.getNodeAs<CXXNewExpr>("Alloc");
78  assert(Alloc && "Matched node bound by 'Alloc' should be either 'CallExpr'"
79  " or 'CXXNewExpr'");
80 
81  const auto *StrLen = Result.Nodes.getNodeAs<CallExpr>("StrLen");
82  const auto *BinOp = Result.Nodes.getNodeAs<BinaryOperator>("BinOp");
83 
84  const StringRef StrLenText = Lexer::getSourceText(
85  CharSourceRange::getTokenRange(StrLen->getSourceRange()),
86  *Result.SourceManager, getLangOpts());
87  const StringRef Arg0Text = Lexer::getSourceText(
88  CharSourceRange::getTokenRange(StrLen->getArg(0)->getSourceRange()),
89  *Result.SourceManager, getLangOpts());
90  const StringRef StrLenBegin = StrLenText.substr(0, StrLenText.find(Arg0Text));
91  const StringRef StrLenEnd = StrLenText.substr(
92  StrLenText.find(Arg0Text) + Arg0Text.size(), StrLenText.size());
93 
94  const StringRef LHSText = Lexer::getSourceText(
95  CharSourceRange::getTokenRange(BinOp->getLHS()->getSourceRange()),
96  *Result.SourceManager, getLangOpts());
97  const StringRef RHSText = Lexer::getSourceText(
98  CharSourceRange::getTokenRange(BinOp->getRHS()->getSourceRange()),
99  *Result.SourceManager, getLangOpts());
100 
101  auto Hint = FixItHint::CreateReplacement(
102  StrLen->getSourceRange(),
103  (StrLenBegin + LHSText + StrLenEnd + " + " + RHSText).str());
104 
105  diag(Alloc->getBeginLoc(),
106  "addition operator is applied to the argument of %0 instead of its "
107  "result")
108  << StrLen->getDirectCallee()->getName() << Hint;
109 }
110 
111 } // namespace bugprone
112 } // namespace tidy
113 } // namespace clang
clang::tidy::cppcoreguidelines::getSourceText
static std::string getSourceText(const CXXDestructorDecl &Destructor)
Definition: VirtualClassDestructorCheck.cpp:112
MisplacedOperatorInStrlenInAllocCheck.h
clang::ast_matchers
Definition: AbseilMatcher.h:14
clang::clangd::check
bool check(llvm::StringRef File, llvm::function_ref< bool(const Position &)> ShouldCheckLine, const ThreadsafeFS &TFS, const ClangdLSPServer::Options &Opts, bool EnableCodeCompletion)
Definition: Check.cpp:259
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27