xref: /llvm-project/clang-tools-extra/clang-tidy/cert/LimitedRandomnessCheck.cpp (revision 7d2ea6c422d3f5712b7253407005e1a465a76946)
1 //===--- LimitedRandomnessCheck.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 "LimitedRandomnessCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 
13 using namespace clang::ast_matchers;
14 
15 namespace clang::tidy::cert {
16 
registerMatchers(MatchFinder * Finder)17 void LimitedRandomnessCheck::registerMatchers(MatchFinder *Finder) {
18   Finder->addMatcher(callExpr(callee(functionDecl(namedDecl(hasName("::rand")),
19                                                   parameterCountIs(0))))
20                          .bind("randomGenerator"),
21                      this);
22 }
23 
check(const MatchFinder::MatchResult & Result)24 void LimitedRandomnessCheck::check(const MatchFinder::MatchResult &Result) {
25   std::string Msg;
26   if (getLangOpts().CPlusPlus)
27     Msg = "; use C++11 random library instead";
28 
29   const auto *MatchedDecl = Result.Nodes.getNodeAs<CallExpr>("randomGenerator");
30   diag(MatchedDecl->getBeginLoc(), "rand() has limited randomness" + Msg);
31 }
32 
33 } // namespace clang::tidy::cert
34