1 //===--- UseAnyOfAllOfCheck.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 "UseAnyOfAllOfCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Analysis/Analyses/ExprMutationAnalyzer.h"
13 #include "clang/Frontend/CompilerInstance.h"
14
15 using namespace clang::ast_matchers;
16
17 namespace clang {
18 namespace {
19 /// Matches a Stmt whose parent is a CompoundStmt, and which is directly
20 /// followed by a Stmt matching the inner matcher.
AST_MATCHER_P(Stmt,nextStmt,ast_matchers::internal::Matcher<Stmt>,InnerMatcher)21 AST_MATCHER_P(Stmt, nextStmt, ast_matchers::internal::Matcher<Stmt>,
22 InnerMatcher) {
23 DynTypedNodeList Parents = Finder->getASTContext().getParents(Node);
24 if (Parents.size() != 1)
25 return false;
26
27 auto *C = Parents[0].get<CompoundStmt>();
28 if (!C)
29 return false;
30
31 const auto *I = llvm::find(C->body(), &Node);
32 assert(I != C->body_end() && "C is parent of Node");
33 if (++I == C->body_end())
34 return false; // Node is last statement.
35
36 return InnerMatcher.matches(**I, Finder, Builder);
37 }
38 } // namespace
39
40 namespace tidy::readability {
41
registerMatchers(MatchFinder * Finder)42 void UseAnyOfAllOfCheck::registerMatchers(MatchFinder *Finder) {
43 auto Returns = [](bool V) {
44 return returnStmt(hasReturnValue(cxxBoolLiteral(equals(V))));
45 };
46
47 auto ReturnsButNotTrue =
48 returnStmt(hasReturnValue(unless(cxxBoolLiteral(equals(true)))));
49 auto ReturnsButNotFalse =
50 returnStmt(hasReturnValue(unless(cxxBoolLiteral(equals(false)))));
51
52 Finder->addMatcher(
53 cxxForRangeStmt(
54 nextStmt(Returns(false).bind("final_return")),
55 hasBody(allOf(hasDescendant(Returns(true)),
56 unless(anyOf(hasDescendant(breakStmt()),
57 hasDescendant(gotoStmt()),
58 hasDescendant(ReturnsButNotTrue))))))
59 .bind("any_of_loop"),
60 this);
61
62 Finder->addMatcher(
63 cxxForRangeStmt(
64 nextStmt(Returns(true).bind("final_return")),
65 hasBody(allOf(hasDescendant(Returns(false)),
66 unless(anyOf(hasDescendant(breakStmt()),
67 hasDescendant(gotoStmt()),
68 hasDescendant(ReturnsButNotFalse))))))
69 .bind("all_of_loop"),
70 this);
71 }
72
isViableLoop(const CXXForRangeStmt & S,ASTContext & Context)73 static bool isViableLoop(const CXXForRangeStmt &S, ASTContext &Context) {
74
75 ExprMutationAnalyzer Mutations(*S.getBody(), Context);
76 if (Mutations.isMutated(S.getLoopVariable()))
77 return false;
78 const auto Matches =
79 match(findAll(declRefExpr().bind("decl_ref")), *S.getBody(), Context);
80
81 return llvm::none_of(Matches, [&Mutations](auto &DeclRef) {
82 // TODO: allow modifications of loop-local variables
83 return Mutations.isMutated(
84 DeclRef.template getNodeAs<DeclRefExpr>("decl_ref")->getDecl());
85 });
86 }
87
check(const MatchFinder::MatchResult & Result)88 void UseAnyOfAllOfCheck::check(const MatchFinder::MatchResult &Result) {
89
90 if (const auto *S = Result.Nodes.getNodeAs<CXXForRangeStmt>("any_of_loop")) {
91 if (!isViableLoop(*S, *Result.Context))
92 return;
93
94 diag(S->getForLoc(), "replace loop by 'std%select{|::ranges}0::any_of()'")
95 << getLangOpts().CPlusPlus20;
96 } else if (const auto *S =
97 Result.Nodes.getNodeAs<CXXForRangeStmt>("all_of_loop")) {
98 if (!isViableLoop(*S, *Result.Context))
99 return;
100
101 diag(S->getForLoc(), "replace loop by 'std%select{|::ranges}0::all_of()'")
102 << getLangOpts().CPlusPlus20;
103 }
104 }
105
106 } // namespace tidy::readability
107 } // namespace clang
108