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authorpatrick <patrick@openbsd.org>2020-08-03 14:31:31 +0000
committerpatrick <patrick@openbsd.org>2020-08-03 14:31:31 +0000
commite5dd70708596ae51455a0ffa086a00c5b29f8583 (patch)
tree5d676f27b570bacf71e786c3b5cff3e6f6679b59 /gnu/llvm/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
parentImport LLVM 10.0.0 release including clang, lld and lldb. (diff)
downloadwireguard-openbsd-e5dd70708596ae51455a0ffa086a00c5b29f8583.tar.xz
wireguard-openbsd-e5dd70708596ae51455a0ffa086a00c5b29f8583.zip
Import LLVM 10.0.0 release including clang, lld and lldb.
ok hackroom tested by plenty
Diffstat (limited to 'gnu/llvm/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp')
-rw-r--r--gnu/llvm/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp419
1 files changed, 419 insertions, 0 deletions
diff --git a/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp b/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
new file mode 100644
index 00000000000..17c813962a2
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+++ b/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
@@ -0,0 +1,419 @@
+//==- 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 "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/IssueHash.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.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;
+
+ typedef void (ExprInspectionChecker::*FnCheck)(const CallExpr *,
+ CheckerContext &C) const;
+
+ ExplodedNode *reportBug(llvm::StringRef Msg, CheckerContext &C) const;
+ ExplodedNode *reportBug(llvm::StringRef Msg, BugReporter &BR,
+ ExplodedNode *N) 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)
+ .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) const {
+ ExplodedNode *N = C.generateNonFatalErrorNode();
+ reportBug(Msg, C.getBugReporter(), N);
+ return N;
+}
+
+ExplodedNode *ExprInspectionChecker::reportBug(llvm::StringRef Msg,
+ BugReporter &BR,
+ ExplodedNode *N) const {
+ if (!N)
+ return nullptr;
+
+ if (!BT)
+ BT.reset(new BugType(this, "Checking analyzer assumptions", "debug"));
+
+ BR.emitReport(std::make_unique<PathSensitiveBugReport>(*BT, Msg, N));
+ 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();
+ State = State->BindExpr(CE, C.getLocationContext(),
+ MR->getExtent(C.getSValBuilder()));
+ 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(SM, 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;
+ }
+
+ SymbolRef Sym = C.getSVal(CE->getArg(0)).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);
+}
+
+void ento::registerExprInspectionChecker(CheckerManager &Mgr) {
+ Mgr.registerChecker<ExprInspectionChecker>();
+}
+
+bool ento::shouldRegisterExprInspectionChecker(const LangOptions &LO) {
+ return true;
+}