CommandProcessorCheck.cpp
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//===-- CommandProcessorCheck.cpp - clang-tidy ----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "CommandProcessorCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace cert {
void CommandProcessorCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
callExpr(
callee(functionDecl(hasAnyName("::system", "::popen", "::_popen"))
.bind("func")),
// Do not diagnose when the call expression passes a null pointer
// constant to system(); that only checks for the presence of a
// command processor, which is not a security risk by itself.
unless(callExpr(callee(functionDecl(hasName("::system"))),
argumentCountIs(1),
hasArgument(0, nullPointerConstant()))))
.bind("expr"),
this);
}
void CommandProcessorCheck::check(const MatchFinder::MatchResult &Result) {
const auto *Fn = Result.Nodes.getNodeAs<FunctionDecl>("func");
const auto *E = Result.Nodes.getNodeAs<CallExpr>("expr");
diag(E->getExprLoc(), "calling %0 uses a command processor") << Fn;
}
} // namespace cert
} // namespace tidy
} // namespace clang