1 //===--- UseBoolLiteralsCheck.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 "UseBoolLiteralsCheck.h"
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 modernize {
19 
UseBoolLiteralsCheck(StringRef Name,ClangTidyContext * Context)20 UseBoolLiteralsCheck::UseBoolLiteralsCheck(StringRef Name,
21                                            ClangTidyContext *Context)
22     : ClangTidyCheck(Name, Context),
23       IgnoreMacros(Options.getLocalOrGlobal("IgnoreMacros", true)) {}
24 
registerMatchers(MatchFinder * Finder)25 void UseBoolLiteralsCheck::registerMatchers(MatchFinder *Finder) {
26   if (!getLangOpts().CPlusPlus)
27     return;
28 
29   Finder->addMatcher(
30       implicitCastExpr(
31           has(ignoringParenImpCasts(integerLiteral().bind("literal"))),
32           hasImplicitDestinationType(qualType(booleanType())),
33           unless(isInTemplateInstantiation()),
34           anyOf(hasParent(explicitCastExpr().bind("cast")), anything())),
35       this);
36 
37   Finder->addMatcher(
38       conditionalOperator(
39           hasParent(implicitCastExpr(
40               hasImplicitDestinationType(qualType(booleanType())),
41               unless(isInTemplateInstantiation()))),
42           eachOf(hasTrueExpression(
43                      ignoringParenImpCasts(integerLiteral().bind("literal"))),
44                  hasFalseExpression(
45                      ignoringParenImpCasts(integerLiteral().bind("literal"))))),
46       this);
47 }
48 
check(const MatchFinder::MatchResult & Result)49 void UseBoolLiteralsCheck::check(const MatchFinder::MatchResult &Result) {
50   const auto *Literal = Result.Nodes.getNodeAs<IntegerLiteral>("literal");
51   const auto *Cast = Result.Nodes.getNodeAs<Expr>("cast");
52   bool LiteralBooleanValue = Literal->getValue().getBoolValue();
53 
54   if (Literal->isInstantiationDependent())
55     return;
56 
57   const Expr *Expression = Cast ? Cast : Literal;
58 
59   bool InMacro = Expression->getBeginLoc().isMacroID();
60 
61   if (InMacro && IgnoreMacros)
62     return;
63 
64   auto Diag =
65       diag(Expression->getExprLoc(),
66            "converting integer literal to bool, use bool literal instead");
67 
68   if (!InMacro)
69     Diag << FixItHint::CreateReplacement(
70         Expression->getSourceRange(), LiteralBooleanValue ? "true" : "false");
71 }
72 
73 } // namespace modernize
74 } // namespace tidy
75 } // namespace clang
76