1 //===--- UseAnyOfAllOfCheck.cpp - clang-tidy-------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "UseAnyOfAllOfCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Analysis/Analyses/ExprMutationAnalyzer.h"
14 #include "clang/Frontend/CompilerInstance.h"
15
16 using namespace clang::ast_matchers;
17
18 namespace clang {
19 namespace {
20 /// Matches a Stmt whose parent is a CompoundStmt, and which is directly
21 /// followed by a Stmt matching the inner matcher.
AST_MATCHER_P(Stmt,nextStmt,ast_matchers::internal::Matcher<Stmt>,InnerMatcher)22 AST_MATCHER_P(Stmt, nextStmt, ast_matchers::internal::Matcher<Stmt>,
23 InnerMatcher) {
24 DynTypedNodeList Parents = Finder->getASTContext().getParents(Node);
25 if (Parents.size() != 1)
26 return false;
27
28 auto *C = Parents[0].get<CompoundStmt>();
29 if (!C)
30 return false;
31
32 const auto *I = llvm::find(C->body(), &Node);
33 assert(I != C->body_end() && "C is parent of Node");
34 if (++I == C->body_end())
35 return false; // Node is last statement.
36
37 return InnerMatcher.matches(**I, Finder, Builder);
38 }
39 } // namespace
40
41 namespace tidy {
42 namespace readability {
43
registerMatchers(MatchFinder * Finder)44 void UseAnyOfAllOfCheck::registerMatchers(MatchFinder *Finder) {
45 auto returns = [](bool V) {
46 return returnStmt(hasReturnValue(cxxBoolLiteral(equals(V))));
47 };
48
49 auto returnsButNotTrue =
50 returnStmt(hasReturnValue(unless(cxxBoolLiteral(equals(true)))));
51 auto returnsButNotFalse =
52 returnStmt(hasReturnValue(unless(cxxBoolLiteral(equals(false)))));
53
54 Finder->addMatcher(
55 cxxForRangeStmt(
56 nextStmt(returns(false).bind("final_return")),
57 hasBody(allOf(hasDescendant(returns(true)),
58 unless(anyOf(hasDescendant(breakStmt()),
59 hasDescendant(gotoStmt()),
60 hasDescendant(returnsButNotTrue))))))
61 .bind("any_of_loop"),
62 this);
63
64 Finder->addMatcher(
65 cxxForRangeStmt(
66 nextStmt(returns(true).bind("final_return")),
67 hasBody(allOf(hasDescendant(returns(false)),
68 unless(anyOf(hasDescendant(breakStmt()),
69 hasDescendant(gotoStmt()),
70 hasDescendant(returnsButNotFalse))))))
71 .bind("all_of_loop"),
72 this);
73 }
74
isViableLoop(const CXXForRangeStmt & S,ASTContext & Context)75 static bool isViableLoop(const CXXForRangeStmt &S, ASTContext &Context) {
76
77 ExprMutationAnalyzer Mutations(*S.getBody(), Context);
78 if (Mutations.isMutated(S.getLoopVariable()))
79 return false;
80 const auto Matches =
81 match(findAll(declRefExpr().bind("decl_ref")), *S.getBody(), Context);
82
83 return llvm::none_of(Matches, [&Mutations](auto &DeclRef) {
84 // TODO: allow modifications of loop-local variables
85 return Mutations.isMutated(
86 DeclRef.template getNodeAs<DeclRefExpr>("decl_ref")->getDecl());
87 });
88 }
89
check(const MatchFinder::MatchResult & Result)90 void UseAnyOfAllOfCheck::check(const MatchFinder::MatchResult &Result) {
91 StringRef Ranges = getLangOpts().CPlusPlus20 ? "::ranges" : "";
92
93 if (const auto *S = Result.Nodes.getNodeAs<CXXForRangeStmt>("any_of_loop")) {
94 if (!isViableLoop(*S, *Result.Context))
95 return;
96
97 diag(S->getForLoc(), "replace loop by 'std%0::any_of()'") << Ranges;
98 } else if (const auto *S =
99 Result.Nodes.getNodeAs<CXXForRangeStmt>("all_of_loop")) {
100 if (!isViableLoop(*S, *Result.Context))
101 return;
102
103 diag(S->getForLoc(), "replace loop by 'std%0::all_of()'") << Ranges;
104 }
105 }
106
107 } // namespace readability
108 } // namespace tidy
109 } // namespace clang
110