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

source code of clang-tools-extra/clang-tidy/bugprone/MisplacedOperatorInStrlenInAllocCheck.cpp