1 files changed, 300 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp b/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
new file mode 100644
index 000000000000..8de653c10f7e
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+++ b/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
@@ -0,0 +1,300 @@
+//==- ExprInspectionChecker.cpp - Used for regression tests ------*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.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/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;
+
+  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 CallExpr *CE, 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)
+
+bool ExprInspectionChecker::evalCall(const CallExpr *CE,
+                                     CheckerContext &C) const {
+  // 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)
+    .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(llvm::make_unique<BugReport>(*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);
+  }
+  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)->getLocStart(), SM);
+  std::string HashContent =
+      GetIssueString(SM, FL, getCheckName().getName(), "Category",
+                     C.getLocationContext()->getDecl(), Opts);
+
+  reportBug(HashContent, C);
+}
+
+void ento::registerExprInspectionChecker(CheckerManager &Mgr) {
+  Mgr.registerChecker<ExprInspectionChecker>();
+}