forked from OSchip/llvm-project
116 lines
4.5 KiB
C++
116 lines
4.5 KiB
C++
//== PointerSortingChecker.cpp --------------------------------- -*- C++ -*--=//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines PointerSortingChecker which checks for non-determinism
|
|
// caused due to sorting containers with pointer-like elements.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "clang/ASTMatchers/ASTMatchFinder.h"
|
|
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
|
|
#include "clang/StaticAnalyzer/Core/Checker.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
|
|
|
|
using namespace clang;
|
|
using namespace ento;
|
|
using namespace ast_matchers;
|
|
|
|
namespace {
|
|
|
|
// ID of a node at which the diagnostic would be emitted.
|
|
constexpr llvm::StringLiteral WarnAtNode = "sort";
|
|
|
|
class PointerSortingChecker : public Checker<check::ASTCodeBody> {
|
|
public:
|
|
void checkASTCodeBody(const Decl *D,
|
|
AnalysisManager &AM,
|
|
BugReporter &BR) const;
|
|
};
|
|
|
|
static void emitDiagnostics(const BoundNodes &Match, const Decl *D,
|
|
BugReporter &BR, AnalysisManager &AM,
|
|
const PointerSortingChecker *Checker) {
|
|
auto *ADC = AM.getAnalysisDeclContext(D);
|
|
|
|
const auto *MarkedStmt = Match.getNodeAs<CallExpr>(WarnAtNode);
|
|
assert(MarkedStmt);
|
|
|
|
auto Range = MarkedStmt->getSourceRange();
|
|
auto Location = PathDiagnosticLocation::createBegin(MarkedStmt,
|
|
BR.getSourceManager(),
|
|
ADC);
|
|
std::string Diagnostics;
|
|
llvm::raw_string_ostream OS(Diagnostics);
|
|
OS << "Sorting pointer-like elements "
|
|
<< "can result in non-deterministic ordering";
|
|
|
|
BR.EmitBasicReport(ADC->getDecl(), Checker,
|
|
"Sorting of pointer-like elements", "Non-determinism",
|
|
OS.str(), Location, Range);
|
|
}
|
|
|
|
decltype(auto) callsName(const char *FunctionName) {
|
|
return callee(functionDecl(hasName(FunctionName)));
|
|
}
|
|
|
|
// FIXME: Currently we simply check if std::sort is used with pointer-like
|
|
// elements. This approach can have a big false positive rate. Using std::sort,
|
|
// std::unique and then erase is common technique for deduplicating a container
|
|
// (which in some cases might even be quicker than using, let's say std::set).
|
|
// In case a container contains arbitrary memory addresses (e.g. multiple
|
|
// things give different stuff but might give the same thing multiple times)
|
|
// which we don't want to do things with more than once, we might use
|
|
// sort-unique-erase and the sort call will emit a report.
|
|
auto matchSortWithPointers() -> decltype(decl()) {
|
|
// Match any of these function calls.
|
|
auto SortFuncM = anyOf(
|
|
callsName("std::is_sorted"),
|
|
callsName("std::nth_element"),
|
|
callsName("std::partial_sort"),
|
|
callsName("std::partition"),
|
|
callsName("std::sort"),
|
|
callsName("std::stable_partition"),
|
|
callsName("std::stable_sort")
|
|
);
|
|
|
|
// Match only if the container has pointer-type elements.
|
|
auto IteratesPointerEltsM = hasArgument(0,
|
|
hasType(cxxRecordDecl(has(
|
|
fieldDecl(hasType(hasCanonicalType(
|
|
pointsTo(hasCanonicalType(pointerType()))
|
|
)))
|
|
))));
|
|
|
|
auto PointerSortM = traverse(
|
|
TK_AsIs,
|
|
stmt(callExpr(allOf(SortFuncM, IteratesPointerEltsM))).bind(WarnAtNode));
|
|
|
|
return decl(forEachDescendant(PointerSortM));
|
|
}
|
|
|
|
void PointerSortingChecker::checkASTCodeBody(const Decl *D,
|
|
AnalysisManager &AM,
|
|
BugReporter &BR) const {
|
|
auto MatcherM = matchSortWithPointers();
|
|
|
|
auto Matches = match(MatcherM, *D, AM.getASTContext());
|
|
for (const auto &Match : Matches)
|
|
emitDiagnostics(Match, D, BR, AM, this);
|
|
}
|
|
|
|
} // end of anonymous namespace
|
|
|
|
void ento::registerPointerSortingChecker(CheckerManager &Mgr) {
|
|
Mgr.registerChecker<PointerSortingChecker>();
|
|
}
|
|
|
|
bool ento::shouldRegisterPointerSortingChecker(const CheckerManager &mgr) {
|
|
const LangOptions &LO = mgr.getLangOpts();
|
|
return LO.CPlusPlus;
|
|
}
|