1 files changed, 0 insertions, 361 deletions
diff --git a/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp b/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
deleted file mode 100644
index 3bf8a1836b19..000000000000
--- a/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
+++ /dev/null
@@ -1,361 +0,0 @@
-//== ArrayBoundCheckerV2.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 ArrayBoundCheckerV2, which is a path-sensitive check
-// which looks for an out-of-bound array element access.
-//
-//===----------------------------------------------------------------------===//
-
-#include "Taint.h"
-#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
-#include "clang/AST/CharUnits.h"
-#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
-#include "clang/StaticAnalyzer/Core/Checker.h"
-#include "clang/StaticAnalyzer/Core/CheckerManager.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/APSIntType.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
-#include "llvm/ADT/SmallString.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace clang;
-using namespace ento;
-using namespace taint;
-
-namespace {
-class ArrayBoundCheckerV2 :
-    public Checker<check::Location> {
-  mutable std::unique_ptr<BuiltinBug> BT;
-
-  enum OOB_Kind { OOB_Precedes, OOB_Excedes, OOB_Tainted };
-
-  void reportOOB(CheckerContext &C, ProgramStateRef errorState, OOB_Kind kind,
-                 std::unique_ptr<BugReporterVisitor> Visitor = nullptr) const;
-
-public:
-  void checkLocation(SVal l, bool isLoad, const Stmt*S,
-                     CheckerContext &C) const;
-};
-
-// FIXME: Eventually replace RegionRawOffset with this class.
-class RegionRawOffsetV2 {
-private:
-  const SubRegion *baseRegion;
-  SVal byteOffset;
-
-  RegionRawOffsetV2()
-    : baseRegion(nullptr), byteOffset(UnknownVal()) {}
-
-public:
-  RegionRawOffsetV2(const SubRegion* base, SVal offset)
-    : baseRegion(base), byteOffset(offset) {}
-
-  NonLoc getByteOffset() const { return byteOffset.castAs<NonLoc>(); }
-  const SubRegion *getRegion() const { return baseRegion; }
-
-  static RegionRawOffsetV2 computeOffset(ProgramStateRef state,
-                                         SValBuilder &svalBuilder,
-                                         SVal location);
-
-  void dump() const;
-  void dumpToStream(raw_ostream &os) const;
-};
-}
-
-static SVal computeExtentBegin(SValBuilder &svalBuilder,
-                               const MemRegion *region) {
-  const MemSpaceRegion *SR = region->getMemorySpace();
-  if (SR->getKind() == MemRegion::UnknownSpaceRegionKind)
-    return UnknownVal();
-  else
-    return svalBuilder.makeZeroArrayIndex();
-}
-
-// TODO: once the constraint manager is smart enough to handle non simplified
-// symbolic expressions remove this function. Note that this can not be used in
-// the constraint manager as is, since this does not handle overflows. It is
-// safe to assume, however, that memory offsets will not overflow.
-static std::pair<NonLoc, nonloc::ConcreteInt>
-getSimplifiedOffsets(NonLoc offset, nonloc::ConcreteInt extent,
-                     SValBuilder &svalBuilder) {
-  Optional<nonloc::SymbolVal> SymVal = offset.getAs<nonloc::SymbolVal>();
-  if (SymVal && SymVal->isExpression()) {
-    if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(SymVal->getSymbol())) {
-      llvm::APSInt constant =
-          APSIntType(extent.getValue()).convert(SIE->getRHS());
-      switch (SIE->getOpcode()) {
-      case BO_Mul:
-        // The constant should never be 0 here, since it the result of scaling
-        // based on the size of a type which is never 0.
-        if ((extent.getValue() % constant) != 0)
-          return std::pair<NonLoc, nonloc::ConcreteInt>(offset, extent);
-        else
-          return getSimplifiedOffsets(
-              nonloc::SymbolVal(SIE->getLHS()),
-              svalBuilder.makeIntVal(extent.getValue() / constant),
-              svalBuilder);
-      case BO_Add:
-        return getSimplifiedOffsets(
-            nonloc::SymbolVal(SIE->getLHS()),
-            svalBuilder.makeIntVal(extent.getValue() - constant), svalBuilder);
-      default:
-        break;
-      }
-    }
-  }
-
-  return std::pair<NonLoc, nonloc::ConcreteInt>(offset, extent);
-}
-
-void ArrayBoundCheckerV2::checkLocation(SVal location, bool isLoad,
-                                        const Stmt* LoadS,
-                                        CheckerContext &checkerContext) const {
-
-  // NOTE: Instead of using ProgramState::assumeInBound(), we are prototyping
-  // some new logic here that reasons directly about memory region extents.
-  // Once that logic is more mature, we can bring it back to assumeInBound()
-  // for all clients to use.
-  //
-  // The algorithm we are using here for bounds checking is to see if the
-  // memory access is within the extent of the base region.  Since we
-  // have some flexibility in defining the base region, we can achieve
-  // various levels of conservatism in our buffer overflow checking.
-  ProgramStateRef state = checkerContext.getState();
-
-  SValBuilder &svalBuilder = checkerContext.getSValBuilder();
-  const RegionRawOffsetV2 &rawOffset =
-    RegionRawOffsetV2::computeOffset(state, svalBuilder, location);
-
-  if (!rawOffset.getRegion())
-    return;
-
-  NonLoc rawOffsetVal = rawOffset.getByteOffset();
-
-  // CHECK LOWER BOUND: Is byteOffset < extent begin?
-  //  If so, we are doing a load/store
-  //  before the first valid offset in the memory region.
-
-  SVal extentBegin = computeExtentBegin(svalBuilder, rawOffset.getRegion());
-
-  if (Optional<NonLoc> NV = extentBegin.getAs<NonLoc>()) {
-    if (NV->getAs<nonloc::ConcreteInt>()) {
-      std::pair<NonLoc, nonloc::ConcreteInt> simplifiedOffsets =
-          getSimplifiedOffsets(rawOffset.getByteOffset(),
-                               NV->castAs<nonloc::ConcreteInt>(),
-                               svalBuilder);
-      rawOffsetVal = simplifiedOffsets.first;
-      *NV = simplifiedOffsets.second;
-    }
-
-    SVal lowerBound = svalBuilder.evalBinOpNN(state, BO_LT, rawOffsetVal, *NV,
-                                              svalBuilder.getConditionType());
-
-    Optional<NonLoc> lowerBoundToCheck = lowerBound.getAs<NonLoc>();
-    if (!lowerBoundToCheck)
-      return;
-
-    ProgramStateRef state_precedesLowerBound, state_withinLowerBound;
-    std::tie(state_precedesLowerBound, state_withinLowerBound) =
-      state->assume(*lowerBoundToCheck);
-
-    // Are we constrained enough to definitely precede the lower bound?
-    if (state_precedesLowerBound && !state_withinLowerBound) {
-      reportOOB(checkerContext, state_precedesLowerBound, OOB_Precedes);
-      return;
-    }
-
-    // Otherwise, assume the constraint of the lower bound.
-    assert(state_withinLowerBound);
-    state = state_withinLowerBound;
-  }
-
-  do {
-    // CHECK UPPER BOUND: Is byteOffset >= extent(baseRegion)?  If so,
-    // we are doing a load/store after the last valid offset.
-    DefinedOrUnknownSVal extentVal =
-      rawOffset.getRegion()->getExtent(svalBuilder);
-    if (!extentVal.getAs<NonLoc>())
-      break;
-
-    if (extentVal.getAs<nonloc::ConcreteInt>()) {
-      std::pair<NonLoc, nonloc::ConcreteInt> simplifiedOffsets =
-          getSimplifiedOffsets(rawOffset.getByteOffset(),
-                               extentVal.castAs<nonloc::ConcreteInt>(),
-                               svalBuilder);
-      rawOffsetVal = simplifiedOffsets.first;
-      extentVal = simplifiedOffsets.second;
-    }
-
-    SVal upperbound = svalBuilder.evalBinOpNN(state, BO_GE, rawOffsetVal,
-                                              extentVal.castAs<NonLoc>(),
-                                              svalBuilder.getConditionType());
-
-    Optional<NonLoc> upperboundToCheck = upperbound.getAs<NonLoc>();
-    if (!upperboundToCheck)
-      break;
-
-    ProgramStateRef state_exceedsUpperBound, state_withinUpperBound;
-    std::tie(state_exceedsUpperBound, state_withinUpperBound) =
-      state->assume(*upperboundToCheck);
-
-    // If we are under constrained and the index variables are tainted, report.
-    if (state_exceedsUpperBound && state_withinUpperBound) {
-      SVal ByteOffset = rawOffset.getByteOffset();
-      if (isTainted(state, ByteOffset)) {
-        reportOOB(checkerContext, state_exceedsUpperBound, OOB_Tainted,
-                  llvm::make_unique<TaintBugVisitor>(ByteOffset));
-        return;
-      }
-    } else if (state_exceedsUpperBound) {
-      // If we are constrained enough to definitely exceed the upper bound,
-      // report.
-      assert(!state_withinUpperBound);
-      reportOOB(checkerContext, state_exceedsUpperBound, OOB_Excedes);
-      return;
-    }
-
-    assert(state_withinUpperBound);
-    state = state_withinUpperBound;
-  }
-  while (false);
-
-  checkerContext.addTransition(state);
-}
-
-void ArrayBoundCheckerV2::reportOOB(
-    CheckerContext &checkerContext, ProgramStateRef errorState, OOB_Kind kind,
-    std::unique_ptr<BugReporterVisitor> Visitor) const {
-
-  ExplodedNode *errorNode = checkerContext.generateErrorNode(errorState);
-  if (!errorNode)
-    return;
-
-  if (!BT)
-    BT.reset(new BuiltinBug(this, "Out-of-bound access"));
-
-  // FIXME: This diagnostics are preliminary.  We should get far better
-  // diagnostics for explaining buffer overruns.
-
-  SmallString<256> buf;
-  llvm::raw_svector_ostream os(buf);
-  os << "Out of bound memory access ";
-  switch (kind) {
-  case OOB_Precedes:
-    os << "(accessed memory precedes memory block)";
-    break;
-  case OOB_Excedes:
-    os << "(access exceeds upper limit of memory block)";
-    break;
-  case OOB_Tainted:
-    os << "(index is tainted)";
-    break;
-  }
-
-  auto BR = llvm::make_unique<BugReport>(*BT, os.str(), errorNode);
-  BR->addVisitor(std::move(Visitor));
-  checkerContext.emitReport(std::move(BR));
-}
-
-#ifndef NDEBUG
-LLVM_DUMP_METHOD void RegionRawOffsetV2::dump() const {
-  dumpToStream(llvm::errs());
-}
-
-void RegionRawOffsetV2::dumpToStream(raw_ostream &os) const {
-  os << "raw_offset_v2{" << getRegion() << ',' << getByteOffset() << '}';
-}
-#endif
-
-// Lazily computes a value to be used by 'computeOffset'.  If 'val'
-// is unknown or undefined, we lazily substitute '0'.  Otherwise,
-// return 'val'.
-static inline SVal getValue(SVal val, SValBuilder &svalBuilder) {
-  return val.getAs<UndefinedVal>() ? svalBuilder.makeArrayIndex(0) : val;
-}
-
-// Scale a base value by a scaling factor, and return the scaled
-// value as an SVal.  Used by 'computeOffset'.
-static inline SVal scaleValue(ProgramStateRef state,
-                              NonLoc baseVal, CharUnits scaling,
-                              SValBuilder &sb) {
-  return sb.evalBinOpNN(state, BO_Mul, baseVal,
-                        sb.makeArrayIndex(scaling.getQuantity()),
-                        sb.getArrayIndexType());
-}
-
-// Add an SVal to another, treating unknown and undefined values as
-// summing to UnknownVal.  Used by 'computeOffset'.
-static SVal addValue(ProgramStateRef state, SVal x, SVal y,
-                     SValBuilder &svalBuilder) {
-  // We treat UnknownVals and UndefinedVals the same here because we
-  // only care about computing offsets.
-  if (x.isUnknownOrUndef() || y.isUnknownOrUndef())
-    return UnknownVal();
-
-  return svalBuilder.evalBinOpNN(state, BO_Add, x.castAs<NonLoc>(),
-                                 y.castAs<NonLoc>(),
-                                 svalBuilder.getArrayIndexType());
-}
-
-/// Compute a raw byte offset from a base region.  Used for array bounds
-/// checking.
-RegionRawOffsetV2 RegionRawOffsetV2::computeOffset(ProgramStateRef state,
-                                                   SValBuilder &svalBuilder,
-                                                   SVal location)
-{
-  const MemRegion *region = location.getAsRegion();
-  SVal offset = UndefinedVal();
-
-  while (region) {
-    switch (region->getKind()) {
-      default: {
-        if (const SubRegion *subReg = dyn_cast<SubRegion>(region)) {
-          offset = getValue(offset, svalBuilder);
-          if (!offset.isUnknownOrUndef())
-            return RegionRawOffsetV2(subReg, offset);
-        }
-        return RegionRawOffsetV2();
-      }
-      case MemRegion::ElementRegionKind: {
-        const ElementRegion *elemReg = cast<ElementRegion>(region);
-        SVal index = elemReg->getIndex();
-        if (!index.getAs<NonLoc>())
-          return RegionRawOffsetV2();
-        QualType elemType = elemReg->getElementType();
-        // If the element is an incomplete type, go no further.
-        ASTContext &astContext = svalBuilder.getContext();
-        if (elemType->isIncompleteType())
-          return RegionRawOffsetV2();
-
-        // Update the offset.
-        offset = addValue(state,
-                          getValue(offset, svalBuilder),
-                          scaleValue(state,
-                          index.castAs<NonLoc>(),
-                          astContext.getTypeSizeInChars(elemType),
-                          svalBuilder),
-                          svalBuilder);
-
-        if (offset.isUnknownOrUndef())
-          return RegionRawOffsetV2();
-
-        region = elemReg->getSuperRegion();
-        continue;
-      }
-    }
-  }
-  return RegionRawOffsetV2();
-}
-
-void ento::registerArrayBoundCheckerV2(CheckerManager &mgr) {
-  mgr.registerChecker<ArrayBoundCheckerV2>();
-}
-
-bool ento::shouldRegisterArrayBoundCheckerV2(const LangOptions &LO) {
-  return true;
-}