10 #include "../utils/Matchers.h"
11 #include "../utils/OptionsUtils.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/ASTMatchers/ASTMatchFinder.h"
14 #include "clang/Lex/Lexer.h"
25 "__builtin_strcasecmp;"
27 "__builtin_strncasecmp;"
69 SuspiciousStringCompareCheck::SuspiciousStringCompareCheck(
72 WarnOnImplicitComparison(Options.get(
"WarnOnImplicitComparison", true)),
73 WarnOnLogicalNotComparison(
74 Options.get(
"WarnOnLogicalNotComparison", false)),
75 StringCompareLikeFunctions(
76 Options.get(
"StringCompareLikeFunctions",
"")) {}
80 Options.
store(Opts,
"WarnOnImplicitComparison", WarnOnImplicitComparison);
81 Options.
store(Opts,
"WarnOnLogicalNotComparison", WarnOnLogicalNotComparison);
82 Options.
store(Opts,
"StringCompareLikeFunctions", StringCompareLikeFunctions);
87 const auto ComparisonUnaryOperator = unaryOperator(hasOperatorName(
"!"));
88 const auto ComparisonBinaryOperator = binaryOperator(isComparisonOperator());
89 const auto ComparisonOperator =
90 expr(anyOf(ComparisonUnaryOperator, ComparisonBinaryOperator));
99 const auto FunctionCompareDecl =
100 functionDecl(hasAnyName(std::vector<StringRef>(FunctionNames.begin(),
101 FunctionNames.end())))
103 const auto DirectStringCompareCallExpr =
104 callExpr(hasDeclaration(FunctionCompareDecl)).bind(
"call");
105 const auto MacroStringCompareCallExpr = conditionalOperator(anyOf(
106 hasTrueExpression(ignoringParenImpCasts(DirectStringCompareCallExpr)),
107 hasFalseExpression(ignoringParenImpCasts(DirectStringCompareCallExpr))));
109 const auto StringCompareCallExpr = ignoringParenImpCasts(
110 anyOf(DirectStringCompareCallExpr, MacroStringCompareCallExpr));
112 if (WarnOnImplicitComparison) {
116 stmt(anyOf(ifStmt(hasCondition(StringCompareCallExpr)),
117 whileStmt(hasCondition(StringCompareCallExpr)),
118 doStmt(hasCondition(StringCompareCallExpr)),
119 forStmt(hasCondition(StringCompareCallExpr)),
120 binaryOperator(hasAnyOperatorName(
"&&",
"||"),
121 hasEitherOperand(StringCompareCallExpr))))
122 .bind(
"missing-comparison"),
126 if (WarnOnLogicalNotComparison) {
129 Finder->addMatcher(unaryOperator(hasOperatorName(
"!"),
130 hasUnaryOperand(ignoringParenImpCasts(
131 StringCompareCallExpr)))
132 .bind(
"logical-not-comparison"),
138 traverse(ast_type_traits::TK_AsIs,
139 implicitCastExpr(unless(hasType(isInteger())),
140 hasSourceExpression(StringCompareCallExpr))
141 .bind(
"invalid-conversion")),
146 binaryOperator(unless(anyOf(isComparisonOperator(), hasOperatorName(
"&&"),
147 hasOperatorName(
"||"), hasOperatorName(
"="))),
148 hasEitherOperand(StringCompareCallExpr))
149 .bind(
"suspicious-operator"),
153 const auto InvalidLiteral = ignoringParenImpCasts(
154 anyOf(integerLiteral(unless(equals(0))),
156 hasOperatorName(
"-"),
157 has(ignoringParenImpCasts(integerLiteral(unless(equals(0)))))),
158 characterLiteral(), cxxBoolLiteral()));
161 binaryOperator(isComparisonOperator(),
162 hasOperands(StringCompareCallExpr, InvalidLiteral))
163 .bind(
"invalid-comparison"),
168 const MatchFinder::MatchResult &Result) {
169 const auto *
Decl = Result.Nodes.getNodeAs<FunctionDecl>(
"decl");
170 const auto *Call = Result.Nodes.getNodeAs<CallExpr>(
"call");
171 assert(
Decl !=
nullptr && Call !=
nullptr);
173 if (Result.Nodes.getNodeAs<Stmt>(
"missing-comparison")) {
174 SourceLocation EndLoc = Lexer::getLocForEndOfToken(
175 Call->getRParenLoc(), 0, Result.Context->getSourceManager(),
178 diag(Call->getBeginLoc(),
179 "function %0 is called without explicitly comparing result")
180 <<
Decl << FixItHint::CreateInsertion(EndLoc,
" != 0");
183 if (
const auto *
E = Result.Nodes.getNodeAs<Expr>(
"logical-not-comparison")) {
184 SourceLocation EndLoc = Lexer::getLocForEndOfToken(
185 Call->getRParenLoc(), 0, Result.Context->getSourceManager(),
187 SourceLocation NotLoc =
E->getBeginLoc();
189 diag(Call->getBeginLoc(),
190 "function %0 is compared using logical not operator")
192 << FixItHint::CreateRemoval(
193 CharSourceRange::getTokenRange(NotLoc, NotLoc))
194 << FixItHint::CreateInsertion(EndLoc,
" == 0");
197 if (Result.Nodes.getNodeAs<Stmt>(
"invalid-comparison")) {
198 diag(Call->getBeginLoc(),
199 "function %0 is compared to a suspicious constant")
203 if (
const auto *BinOp =
204 Result.Nodes.getNodeAs<BinaryOperator>(
"suspicious-operator")) {
205 diag(Call->getBeginLoc(),
"results of function %0 used by operator '%1'")
206 <<
Decl << BinOp->getOpcodeStr();
209 if (Result.Nodes.getNodeAs<Stmt>(
"invalid-conversion")) {
210 diag(Call->getBeginLoc(),
"function %0 has suspicious implicit cast")