453 lines
16 KiB
C++
453 lines
16 KiB
C++
//==- ExprInspectionChecker.cpp - Used for regression tests ------*- 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "Taint.h"
|
|
#include "clang/Analysis/IssueHash.h"
|
|
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
|
|
#include "clang/StaticAnalyzer/Checkers/SValExplainer.h"
|
|
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
|
|
#include "clang/StaticAnalyzer/Core/Checker.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/DynamicSize.h"
|
|
#include "llvm/ADT/StringSwitch.h"
|
|
#include "llvm/Support/ScopedPrinter.h"
|
|
|
|
using namespace clang;
|
|
using namespace ento;
|
|
|
|
namespace {
|
|
class ExprInspectionChecker : public Checker<eval::Call, check::DeadSymbols,
|
|
check::EndAnalysis> {
|
|
mutable std::unique_ptr<BugType> BT;
|
|
|
|
// These stats are per-analysis, not per-branch, hence they shouldn't
|
|
// stay inside the program state.
|
|
struct ReachedStat {
|
|
ExplodedNode *ExampleNode;
|
|
unsigned NumTimesReached;
|
|
};
|
|
mutable llvm::DenseMap<const CallExpr *, ReachedStat> ReachedStats;
|
|
|
|
void analyzerEval(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerCheckInlined(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerWarnIfReached(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerNumTimesReached(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerCrash(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerWarnOnDeadSymbol(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerDump(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerExplain(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerPrintState(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerGetExtent(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerHashDump(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerDenote(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerExpress(const CallExpr *CE, CheckerContext &C) const;
|
|
void analyzerIsTainted(const CallExpr *CE, CheckerContext &C) const;
|
|
|
|
typedef void (ExprInspectionChecker::*FnCheck)(const CallExpr *,
|
|
CheckerContext &C) const;
|
|
|
|
// Optional parameter `ExprVal` for expression value to be marked interesting.
|
|
ExplodedNode *reportBug(llvm::StringRef Msg, CheckerContext &C,
|
|
Optional<SVal> ExprVal = None) const;
|
|
ExplodedNode *reportBug(llvm::StringRef Msg, BugReporter &BR,
|
|
ExplodedNode *N,
|
|
Optional<SVal> ExprVal = None) const;
|
|
|
|
public:
|
|
bool evalCall(const CallEvent &Call, CheckerContext &C) const;
|
|
void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
|
|
void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR,
|
|
ExprEngine &Eng) const;
|
|
};
|
|
}
|
|
|
|
REGISTER_SET_WITH_PROGRAMSTATE(MarkedSymbols, SymbolRef)
|
|
REGISTER_MAP_WITH_PROGRAMSTATE(DenotedSymbols, SymbolRef, const StringLiteral *)
|
|
|
|
bool ExprInspectionChecker::evalCall(const CallEvent &Call,
|
|
CheckerContext &C) const {
|
|
const auto *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
|
|
if (!CE)
|
|
return false;
|
|
|
|
// These checks should have no effect on the surrounding environment
|
|
// (globals should not be invalidated, etc), hence the use of evalCall.
|
|
FnCheck Handler =
|
|
llvm::StringSwitch<FnCheck>(C.getCalleeName(CE))
|
|
.Case("clang_analyzer_eval", &ExprInspectionChecker::analyzerEval)
|
|
.Case("clang_analyzer_checkInlined",
|
|
&ExprInspectionChecker::analyzerCheckInlined)
|
|
.Case("clang_analyzer_crash", &ExprInspectionChecker::analyzerCrash)
|
|
.Case("clang_analyzer_warnIfReached",
|
|
&ExprInspectionChecker::analyzerWarnIfReached)
|
|
.Case("clang_analyzer_warnOnDeadSymbol",
|
|
&ExprInspectionChecker::analyzerWarnOnDeadSymbol)
|
|
.StartsWith("clang_analyzer_explain",
|
|
&ExprInspectionChecker::analyzerExplain)
|
|
.StartsWith("clang_analyzer_dump",
|
|
&ExprInspectionChecker::analyzerDump)
|
|
.Case("clang_analyzer_getExtent",
|
|
&ExprInspectionChecker::analyzerGetExtent)
|
|
.Case("clang_analyzer_printState",
|
|
&ExprInspectionChecker::analyzerPrintState)
|
|
.Case("clang_analyzer_numTimesReached",
|
|
&ExprInspectionChecker::analyzerNumTimesReached)
|
|
.Case("clang_analyzer_hashDump",
|
|
&ExprInspectionChecker::analyzerHashDump)
|
|
.Case("clang_analyzer_denote", &ExprInspectionChecker::analyzerDenote)
|
|
.Case("clang_analyzer_express",
|
|
&ExprInspectionChecker::analyzerExpress)
|
|
.StartsWith("clang_analyzer_isTainted",
|
|
&ExprInspectionChecker::analyzerIsTainted)
|
|
.Default(nullptr);
|
|
|
|
if (!Handler)
|
|
return false;
|
|
|
|
(this->*Handler)(CE, C);
|
|
return true;
|
|
}
|
|
|
|
static const char *getArgumentValueString(const CallExpr *CE,
|
|
CheckerContext &C) {
|
|
if (CE->getNumArgs() == 0)
|
|
return "Missing assertion argument";
|
|
|
|
ExplodedNode *N = C.getPredecessor();
|
|
const LocationContext *LC = N->getLocationContext();
|
|
ProgramStateRef State = N->getState();
|
|
|
|
const Expr *Assertion = CE->getArg(0);
|
|
SVal AssertionVal = State->getSVal(Assertion, LC);
|
|
|
|
if (AssertionVal.isUndef())
|
|
return "UNDEFINED";
|
|
|
|
ProgramStateRef StTrue, StFalse;
|
|
std::tie(StTrue, StFalse) =
|
|
State->assume(AssertionVal.castAs<DefinedOrUnknownSVal>());
|
|
|
|
if (StTrue) {
|
|
if (StFalse)
|
|
return "UNKNOWN";
|
|
else
|
|
return "TRUE";
|
|
} else {
|
|
if (StFalse)
|
|
return "FALSE";
|
|
else
|
|
llvm_unreachable("Invalid constraint; neither true or false.");
|
|
}
|
|
}
|
|
|
|
ExplodedNode *ExprInspectionChecker::reportBug(llvm::StringRef Msg,
|
|
CheckerContext &C,
|
|
Optional<SVal> ExprVal) const {
|
|
ExplodedNode *N = C.generateNonFatalErrorNode();
|
|
reportBug(Msg, C.getBugReporter(), N, ExprVal);
|
|
return N;
|
|
}
|
|
|
|
ExplodedNode *ExprInspectionChecker::reportBug(llvm::StringRef Msg,
|
|
BugReporter &BR,
|
|
ExplodedNode *N,
|
|
Optional<SVal> ExprVal) const {
|
|
if (!N)
|
|
return nullptr;
|
|
|
|
if (!BT)
|
|
BT.reset(new BugType(this, "Checking analyzer assumptions", "debug"));
|
|
|
|
auto R = std::make_unique<PathSensitiveBugReport>(*BT, Msg, N);
|
|
if (ExprVal) {
|
|
R->markInteresting(*ExprVal);
|
|
}
|
|
BR.emitReport(std::move(R));
|
|
return N;
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerEval(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
const LocationContext *LC = C.getPredecessor()->getLocationContext();
|
|
|
|
// A specific instantiation of an inlined function may have more constrained
|
|
// values than can generally be assumed. Skip the check.
|
|
if (LC->getStackFrame()->getParent() != nullptr)
|
|
return;
|
|
|
|
reportBug(getArgumentValueString(CE, C), C);
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerWarnIfReached(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
reportBug("REACHABLE", C);
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerNumTimesReached(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
++ReachedStats[CE].NumTimesReached;
|
|
if (!ReachedStats[CE].ExampleNode) {
|
|
// Later, in checkEndAnalysis, we'd throw a report against it.
|
|
ReachedStats[CE].ExampleNode = C.generateNonFatalErrorNode();
|
|
}
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerCheckInlined(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
const LocationContext *LC = C.getPredecessor()->getLocationContext();
|
|
|
|
// An inlined function could conceivably also be analyzed as a top-level
|
|
// function. We ignore this case and only emit a message (TRUE or FALSE)
|
|
// when we are analyzing it as an inlined function. This means that
|
|
// clang_analyzer_checkInlined(true) should always print TRUE, but
|
|
// clang_analyzer_checkInlined(false) should never actually print anything.
|
|
if (LC->getStackFrame()->getParent() == nullptr)
|
|
return;
|
|
|
|
reportBug(getArgumentValueString(CE, C), C);
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerExplain(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
if (CE->getNumArgs() == 0) {
|
|
reportBug("Missing argument for explaining", C);
|
|
return;
|
|
}
|
|
|
|
SVal V = C.getSVal(CE->getArg(0));
|
|
SValExplainer Ex(C.getASTContext());
|
|
reportBug(Ex.Visit(V), C);
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerDump(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
if (CE->getNumArgs() == 0) {
|
|
reportBug("Missing argument for dumping", C);
|
|
return;
|
|
}
|
|
|
|
SVal V = C.getSVal(CE->getArg(0));
|
|
|
|
llvm::SmallString<32> Str;
|
|
llvm::raw_svector_ostream OS(Str);
|
|
V.dumpToStream(OS);
|
|
reportBug(OS.str(), C);
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerGetExtent(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
if (CE->getNumArgs() == 0) {
|
|
reportBug("Missing region for obtaining extent", C);
|
|
return;
|
|
}
|
|
|
|
auto MR = dyn_cast_or_null<SubRegion>(C.getSVal(CE->getArg(0)).getAsRegion());
|
|
if (!MR) {
|
|
reportBug("Obtaining extent of a non-region", C);
|
|
return;
|
|
}
|
|
|
|
ProgramStateRef State = C.getState();
|
|
DefinedOrUnknownSVal Size = getDynamicSize(State, MR, C.getSValBuilder());
|
|
|
|
State = State->BindExpr(CE, C.getLocationContext(), Size);
|
|
C.addTransition(State);
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerPrintState(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
C.getState()->dump();
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerWarnOnDeadSymbol(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
if (CE->getNumArgs() == 0)
|
|
return;
|
|
SVal Val = C.getSVal(CE->getArg(0));
|
|
SymbolRef Sym = Val.getAsSymbol();
|
|
if (!Sym)
|
|
return;
|
|
|
|
ProgramStateRef State = C.getState();
|
|
State = State->add<MarkedSymbols>(Sym);
|
|
C.addTransition(State);
|
|
}
|
|
|
|
void ExprInspectionChecker::checkDeadSymbols(SymbolReaper &SymReaper,
|
|
CheckerContext &C) const {
|
|
ProgramStateRef State = C.getState();
|
|
const MarkedSymbolsTy &Syms = State->get<MarkedSymbols>();
|
|
ExplodedNode *N = C.getPredecessor();
|
|
for (auto I = Syms.begin(), E = Syms.end(); I != E; ++I) {
|
|
SymbolRef Sym = *I;
|
|
if (!SymReaper.isDead(Sym))
|
|
continue;
|
|
|
|
// The non-fatal error node should be the same for all reports.
|
|
if (ExplodedNode *BugNode = reportBug("SYMBOL DEAD", C))
|
|
N = BugNode;
|
|
State = State->remove<MarkedSymbols>(Sym);
|
|
}
|
|
|
|
for (auto I : State->get<DenotedSymbols>()) {
|
|
SymbolRef Sym = I.first;
|
|
if (!SymReaper.isLive(Sym))
|
|
State = State->remove<DenotedSymbols>(Sym);
|
|
}
|
|
|
|
C.addTransition(State, N);
|
|
}
|
|
|
|
void ExprInspectionChecker::checkEndAnalysis(ExplodedGraph &G, BugReporter &BR,
|
|
ExprEngine &Eng) const {
|
|
for (auto Item: ReachedStats) {
|
|
unsigned NumTimesReached = Item.second.NumTimesReached;
|
|
ExplodedNode *N = Item.second.ExampleNode;
|
|
|
|
reportBug(llvm::to_string(NumTimesReached), BR, N);
|
|
}
|
|
ReachedStats.clear();
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerCrash(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
LLVM_BUILTIN_TRAP;
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerHashDump(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
const LangOptions &Opts = C.getLangOpts();
|
|
const SourceManager &SM = C.getSourceManager();
|
|
FullSourceLoc FL(CE->getArg(0)->getBeginLoc(), SM);
|
|
std::string HashContent =
|
|
getIssueString(FL, getCheckerName().getName(), "Category",
|
|
C.getLocationContext()->getDecl(), Opts);
|
|
|
|
reportBug(HashContent, C);
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerDenote(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
if (CE->getNumArgs() < 2) {
|
|
reportBug("clang_analyzer_denote() requires a symbol and a string literal",
|
|
C);
|
|
return;
|
|
}
|
|
|
|
SymbolRef Sym = C.getSVal(CE->getArg(0)).getAsSymbol();
|
|
if (!Sym) {
|
|
reportBug("Not a symbol", C);
|
|
return;
|
|
}
|
|
|
|
const auto *E = dyn_cast<StringLiteral>(CE->getArg(1)->IgnoreParenCasts());
|
|
if (!E) {
|
|
reportBug("Not a string literal", C);
|
|
return;
|
|
}
|
|
|
|
ProgramStateRef State = C.getState();
|
|
|
|
C.addTransition(C.getState()->set<DenotedSymbols>(Sym, E));
|
|
}
|
|
|
|
namespace {
|
|
class SymbolExpressor
|
|
: public SymExprVisitor<SymbolExpressor, Optional<std::string>> {
|
|
ProgramStateRef State;
|
|
|
|
public:
|
|
SymbolExpressor(ProgramStateRef State) : State(State) {}
|
|
|
|
Optional<std::string> lookup(const SymExpr *S) {
|
|
if (const StringLiteral *const *SLPtr = State->get<DenotedSymbols>(S)) {
|
|
const StringLiteral *SL = *SLPtr;
|
|
return std::string(SL->getBytes());
|
|
}
|
|
return None;
|
|
}
|
|
|
|
Optional<std::string> VisitSymExpr(const SymExpr *S) {
|
|
return lookup(S);
|
|
}
|
|
|
|
Optional<std::string> VisitSymIntExpr(const SymIntExpr *S) {
|
|
if (Optional<std::string> Str = lookup(S))
|
|
return Str;
|
|
if (Optional<std::string> Str = Visit(S->getLHS()))
|
|
return (*Str + " " + BinaryOperator::getOpcodeStr(S->getOpcode()) + " " +
|
|
std::to_string(S->getRHS().getLimitedValue()) +
|
|
(S->getRHS().isUnsigned() ? "U" : ""))
|
|
.str();
|
|
return None;
|
|
}
|
|
|
|
Optional<std::string> VisitSymSymExpr(const SymSymExpr *S) {
|
|
if (Optional<std::string> Str = lookup(S))
|
|
return Str;
|
|
if (Optional<std::string> Str1 = Visit(S->getLHS()))
|
|
if (Optional<std::string> Str2 = Visit(S->getRHS()))
|
|
return (*Str1 + " " + BinaryOperator::getOpcodeStr(S->getOpcode()) +
|
|
" " + *Str2).str();
|
|
return None;
|
|
}
|
|
|
|
Optional<std::string> VisitSymbolCast(const SymbolCast *S) {
|
|
if (Optional<std::string> Str = lookup(S))
|
|
return Str;
|
|
if (Optional<std::string> Str = Visit(S->getOperand()))
|
|
return (Twine("(") + S->getType().getAsString() + ")" + *Str).str();
|
|
return None;
|
|
}
|
|
};
|
|
} // namespace
|
|
|
|
void ExprInspectionChecker::analyzerExpress(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
if (CE->getNumArgs() == 0) {
|
|
reportBug("clang_analyzer_express() requires a symbol", C);
|
|
return;
|
|
}
|
|
|
|
SVal ArgVal = C.getSVal(CE->getArg(0));
|
|
SymbolRef Sym = ArgVal.getAsSymbol();
|
|
if (!Sym) {
|
|
reportBug("Not a symbol", C);
|
|
return;
|
|
}
|
|
|
|
SymbolExpressor V(C.getState());
|
|
auto Str = V.Visit(Sym);
|
|
if (!Str) {
|
|
reportBug("Unable to express", C);
|
|
return;
|
|
}
|
|
|
|
reportBug(*Str, C, ArgVal);
|
|
}
|
|
|
|
void ExprInspectionChecker::analyzerIsTainted(const CallExpr *CE,
|
|
CheckerContext &C) const {
|
|
if (CE->getNumArgs() != 1) {
|
|
reportBug("clang_analyzer_isTainted() requires exactly one argument", C);
|
|
return;
|
|
}
|
|
const bool IsTainted =
|
|
taint::isTainted(C.getState(), CE->getArg(0), C.getLocationContext());
|
|
reportBug(IsTainted ? "YES" : "NO", C);
|
|
}
|
|
|
|
void ento::registerExprInspectionChecker(CheckerManager &Mgr) {
|
|
Mgr.registerChecker<ExprInspectionChecker>();
|
|
}
|
|
|
|
bool ento::shouldRegisterExprInspectionChecker(const CheckerManager &mgr) {
|
|
return true;
|
|
}
|