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//===-- MPIChecker.cpp - Checker Entry Point Class --------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file defines the main class of MPI-Checker which serves as an entry
/// point. It is created once for each translation unit analysed.
/// The checker defines path-sensitive checks, to verify correct usage of the
/// MPI API.
///
//===----------------------------------------------------------------------===//
#include "MPIChecker.h"
#include "../ClangSACheckers.h"
namespace clang {
namespace ento {
namespace mpi {
void MPIChecker::checkDoubleNonblocking(const CallEvent &PreCallEvent,
CheckerContext &Ctx) const {
if (!FuncClassifier->isNonBlockingType(PreCallEvent.getCalleeIdentifier())) {
return;
}
const MemRegion *const MR =
PreCallEvent.getArgSVal(PreCallEvent.getNumArgs() - 1).getAsRegion();
if (!MR)
return;
const ElementRegion *const ER = dyn_cast<ElementRegion>(MR);
// The region must be typed, in order to reason about it.
if (!isa<TypedRegion>(MR) || (ER && !isa<TypedRegion>(ER->getSuperRegion())))
return;
ProgramStateRef State = Ctx.getState();
const Request *const Req = State->get<RequestMap>(MR);
// double nonblocking detected
if (Req && Req->CurrentState == Request::State::Nonblocking) {
ExplodedNode *ErrorNode = Ctx.generateNonFatalErrorNode();
BReporter.reportDoubleNonblocking(PreCallEvent, *Req, MR, ErrorNode,
Ctx.getBugReporter());
Ctx.addTransition(ErrorNode->getState(), ErrorNode);
}
// no error
else {
State = State->set<RequestMap>(MR, Request::State::Nonblocking);
Ctx.addTransition(State);
}
}
void MPIChecker::checkUnmatchedWaits(const CallEvent &PreCallEvent,
CheckerContext &Ctx) const {
if (!FuncClassifier->isWaitType(PreCallEvent.getCalleeIdentifier()))
return;
const MemRegion *const MR = topRegionUsedByWait(PreCallEvent);
if (!MR)
return;
const ElementRegion *const ER = dyn_cast<ElementRegion>(MR);
// The region must be typed, in order to reason about it.
if (!isa<TypedRegion>(MR) || (ER && !isa<TypedRegion>(ER->getSuperRegion())))
return;
llvm::SmallVector<const MemRegion *, 2> ReqRegions;
allRegionsUsedByWait(ReqRegions, MR, PreCallEvent, Ctx);
if (ReqRegions.empty())
return;
ProgramStateRef State = Ctx.getState();
static CheckerProgramPointTag Tag("MPI-Checker", "UnmatchedWait");
ExplodedNode *ErrorNode{nullptr};
// Check all request regions used by the wait function.
for (const auto &ReqRegion : ReqRegions) {
const Request *const Req = State->get<RequestMap>(ReqRegion);
State = State->set<RequestMap>(ReqRegion, Request::State::Wait);
if (!Req) {
if (!ErrorNode) {
ErrorNode = Ctx.generateNonFatalErrorNode(State, &Tag);
State = ErrorNode->getState();
}
// A wait has no matching nonblocking call.
BReporter.reportUnmatchedWait(PreCallEvent, ReqRegion, ErrorNode,
Ctx.getBugReporter());
}
}
if (!ErrorNode) {
Ctx.addTransition(State);
} else {
Ctx.addTransition(State, ErrorNode);
}
}
void MPIChecker::checkMissingWaits(SymbolReaper &SymReaper,
CheckerContext &Ctx) const {
if (!SymReaper.hasDeadSymbols())
return;
ProgramStateRef State = Ctx.getState();
const auto &Requests = State->get<RequestMap>();
if (Requests.isEmpty())
return;
static CheckerProgramPointTag Tag("MPI-Checker", "MissingWait");
ExplodedNode *ErrorNode{nullptr};
auto ReqMap = State->get<RequestMap>();
for (const auto &Req : ReqMap) {
if (!SymReaper.isLiveRegion(Req.first)) {
if (Req.second.CurrentState == Request::State::Nonblocking) {
if (!ErrorNode) {
ErrorNode = Ctx.generateNonFatalErrorNode(State, &Tag);
State = ErrorNode->getState();
}
BReporter.reportMissingWait(Req.second, Req.first, ErrorNode,
Ctx.getBugReporter());
}
State = State->remove<RequestMap>(Req.first);
}
}
// Transition to update the state regarding removed requests.
if (!ErrorNode) {
Ctx.addTransition(State);
} else {
Ctx.addTransition(State, ErrorNode);
}
}
const MemRegion *MPIChecker::topRegionUsedByWait(const CallEvent &CE) const {
if (FuncClassifier->isMPI_Wait(CE.getCalleeIdentifier())) {
return CE.getArgSVal(0).getAsRegion();
} else if (FuncClassifier->isMPI_Waitall(CE.getCalleeIdentifier())) {
return CE.getArgSVal(1).getAsRegion();
} else {
return (const MemRegion *)nullptr;
}
}
void MPIChecker::allRegionsUsedByWait(
llvm::SmallVector<const MemRegion *, 2> &ReqRegions,
const MemRegion *const MR, const CallEvent &CE, CheckerContext &Ctx) const {
MemRegionManager *const RegionManager = MR->getMemRegionManager();
if (FuncClassifier->isMPI_Waitall(CE.getCalleeIdentifier())) {
const SubRegion *SuperRegion{nullptr};
if (const ElementRegion *const ER = MR->getAs<ElementRegion>()) {
SuperRegion = cast<SubRegion>(ER->getSuperRegion());
}
// A single request is passed to MPI_Waitall.
if (!SuperRegion) {
ReqRegions.push_back(MR);
return;
}
const auto &Size = Ctx.getStoreManager().getSizeInElements(
Ctx.getState(), SuperRegion,
CE.getArgExpr(1)->getType()->getPointeeType());
const llvm::APSInt &ArrSize = Size.getAs<nonloc::ConcreteInt>()->getValue();
for (size_t i = 0; i < ArrSize; ++i) {
const NonLoc Idx = Ctx.getSValBuilder().makeArrayIndex(i);
const ElementRegion *const ER = RegionManager->getElementRegion(
CE.getArgExpr(1)->getType()->getPointeeType(), Idx, SuperRegion,
Ctx.getASTContext());
ReqRegions.push_back(ER->getAs<MemRegion>());
}
} else if (FuncClassifier->isMPI_Wait(CE.getCalleeIdentifier())) {
ReqRegions.push_back(MR);
}
}
} // end of namespace: mpi
} // end of namespace: ento
} // end of namespace: clang
// Registers the checker for static analysis.
void clang::ento::registerMPIChecker(CheckerManager &MGR) {
MGR.registerChecker<clang::ento::mpi::MPIChecker>();
}
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