forked from OSchip/llvm-project
790 lines
30 KiB
C++
790 lines
30 KiB
C++
//== RangeConstraintManager.cpp - Manage range constraints.------*- C++ -*--==//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines RangeConstraintManager, a class that tracks simple
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// equality and inequality constraints on symbolic values of ProgramState.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Basic/JsonSupport.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/APSIntType.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h"
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#include "llvm/ADT/FoldingSet.h"
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#include "llvm/ADT/ImmutableSet.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace clang;
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using namespace ento;
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void RangeSet::IntersectInRange(BasicValueFactory &BV, Factory &F,
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const llvm::APSInt &Lower, const llvm::APSInt &Upper,
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PrimRangeSet &newRanges, PrimRangeSet::iterator &i,
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PrimRangeSet::iterator &e) const {
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// There are six cases for each range R in the set:
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// 1. R is entirely before the intersection range.
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// 2. R is entirely after the intersection range.
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// 3. R contains the entire intersection range.
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// 4. R starts before the intersection range and ends in the middle.
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// 5. R starts in the middle of the intersection range and ends after it.
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// 6. R is entirely contained in the intersection range.
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// These correspond to each of the conditions below.
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for (/* i = begin(), e = end() */; i != e; ++i) {
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if (i->To() < Lower) {
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continue;
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}
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if (i->From() > Upper) {
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break;
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}
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if (i->Includes(Lower)) {
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if (i->Includes(Upper)) {
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newRanges =
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F.add(newRanges, Range(BV.getValue(Lower), BV.getValue(Upper)));
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break;
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} else
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newRanges = F.add(newRanges, Range(BV.getValue(Lower), i->To()));
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} else {
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if (i->Includes(Upper)) {
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newRanges = F.add(newRanges, Range(i->From(), BV.getValue(Upper)));
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break;
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} else
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newRanges = F.add(newRanges, *i);
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}
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}
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}
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const llvm::APSInt &RangeSet::getMinValue() const {
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assert(!isEmpty());
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return ranges.begin()->From();
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}
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bool RangeSet::pin(llvm::APSInt &Lower, llvm::APSInt &Upper) const {
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// This function has nine cases, the cartesian product of range-testing
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// both the upper and lower bounds against the symbol's type.
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// Each case requires a different pinning operation.
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// The function returns false if the described range is entirely outside
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// the range of values for the associated symbol.
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APSIntType Type(getMinValue());
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APSIntType::RangeTestResultKind LowerTest = Type.testInRange(Lower, true);
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APSIntType::RangeTestResultKind UpperTest = Type.testInRange(Upper, true);
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switch (LowerTest) {
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case APSIntType::RTR_Below:
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switch (UpperTest) {
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case APSIntType::RTR_Below:
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// The entire range is outside the symbol's set of possible values.
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// If this is a conventionally-ordered range, the state is infeasible.
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if (Lower <= Upper)
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return false;
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// However, if the range wraps around, it spans all possible values.
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Lower = Type.getMinValue();
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Upper = Type.getMaxValue();
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break;
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case APSIntType::RTR_Within:
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// The range starts below what's possible but ends within it. Pin.
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Lower = Type.getMinValue();
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Type.apply(Upper);
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break;
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case APSIntType::RTR_Above:
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// The range spans all possible values for the symbol. Pin.
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Lower = Type.getMinValue();
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Upper = Type.getMaxValue();
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break;
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}
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break;
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case APSIntType::RTR_Within:
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switch (UpperTest) {
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case APSIntType::RTR_Below:
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// The range wraps around, but all lower values are not possible.
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Type.apply(Lower);
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Upper = Type.getMaxValue();
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break;
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case APSIntType::RTR_Within:
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// The range may or may not wrap around, but both limits are valid.
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Type.apply(Lower);
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Type.apply(Upper);
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break;
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case APSIntType::RTR_Above:
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// The range starts within what's possible but ends above it. Pin.
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Type.apply(Lower);
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Upper = Type.getMaxValue();
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break;
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}
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break;
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case APSIntType::RTR_Above:
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switch (UpperTest) {
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case APSIntType::RTR_Below:
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// The range wraps but is outside the symbol's set of possible values.
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return false;
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case APSIntType::RTR_Within:
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// The range starts above what's possible but ends within it (wrap).
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Lower = Type.getMinValue();
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Type.apply(Upper);
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break;
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case APSIntType::RTR_Above:
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// The entire range is outside the symbol's set of possible values.
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// If this is a conventionally-ordered range, the state is infeasible.
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if (Lower <= Upper)
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return false;
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// However, if the range wraps around, it spans all possible values.
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Lower = Type.getMinValue();
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Upper = Type.getMaxValue();
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break;
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}
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break;
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}
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return true;
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}
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// Returns a set containing the values in the receiving set, intersected with
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// the closed range [Lower, Upper]. Unlike the Range type, this range uses
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// modular arithmetic, corresponding to the common treatment of C integer
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// overflow. Thus, if the Lower bound is greater than the Upper bound, the
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// range is taken to wrap around. This is equivalent to taking the
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// intersection with the two ranges [Min, Upper] and [Lower, Max],
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// or, alternatively, /removing/ all integers between Upper and Lower.
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RangeSet RangeSet::Intersect(BasicValueFactory &BV, Factory &F,
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llvm::APSInt Lower, llvm::APSInt Upper) const {
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if (!pin(Lower, Upper))
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return F.getEmptySet();
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PrimRangeSet newRanges = F.getEmptySet();
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PrimRangeSet::iterator i = begin(), e = end();
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if (Lower <= Upper)
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IntersectInRange(BV, F, Lower, Upper, newRanges, i, e);
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else {
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// The order of the next two statements is important!
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// IntersectInRange() does not reset the iteration state for i and e.
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// Therefore, the lower range most be handled first.
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IntersectInRange(BV, F, BV.getMinValue(Upper), Upper, newRanges, i, e);
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IntersectInRange(BV, F, Lower, BV.getMaxValue(Lower), newRanges, i, e);
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}
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return newRanges;
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}
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// Returns a set containing the values in the receiving set, intersected with
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// the range set passed as parameter.
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RangeSet RangeSet::Intersect(BasicValueFactory &BV, Factory &F,
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const RangeSet &Other) const {
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PrimRangeSet newRanges = F.getEmptySet();
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for (iterator i = Other.begin(), e = Other.end(); i != e; ++i) {
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RangeSet newPiece = Intersect(BV, F, i->From(), i->To());
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for (iterator j = newPiece.begin(), ee = newPiece.end(); j != ee; ++j) {
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newRanges = F.add(newRanges, *j);
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}
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}
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return newRanges;
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}
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// Turn all [A, B] ranges to [-B, -A]. Ranges [MIN, B] are turned to range set
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// [MIN, MIN] U [-B, MAX], when MIN and MAX are the minimal and the maximal
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// signed values of the type.
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RangeSet RangeSet::Negate(BasicValueFactory &BV, Factory &F) const {
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PrimRangeSet newRanges = F.getEmptySet();
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for (iterator i = begin(), e = end(); i != e; ++i) {
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const llvm::APSInt &from = i->From(), &to = i->To();
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const llvm::APSInt &newTo = (from.isMinSignedValue() ?
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BV.getMaxValue(from) :
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BV.getValue(- from));
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if (to.isMaxSignedValue() && !newRanges.isEmpty() &&
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newRanges.begin()->From().isMinSignedValue()) {
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assert(newRanges.begin()->To().isMinSignedValue() &&
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"Ranges should not overlap");
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assert(!from.isMinSignedValue() && "Ranges should not overlap");
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const llvm::APSInt &newFrom = newRanges.begin()->From();
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newRanges =
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F.add(F.remove(newRanges, *newRanges.begin()), Range(newFrom, newTo));
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} else if (!to.isMinSignedValue()) {
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const llvm::APSInt &newFrom = BV.getValue(- to);
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newRanges = F.add(newRanges, Range(newFrom, newTo));
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}
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if (from.isMinSignedValue()) {
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newRanges = F.add(newRanges, Range(BV.getMinValue(from),
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BV.getMinValue(from)));
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}
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}
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return newRanges;
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}
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void RangeSet::print(raw_ostream &os) const {
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bool isFirst = true;
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os << "{ ";
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for (iterator i = begin(), e = end(); i != e; ++i) {
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if (isFirst)
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isFirst = false;
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else
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os << ", ";
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os << '[' << i->From().toString(10) << ", " << i->To().toString(10)
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<< ']';
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}
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os << " }";
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}
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namespace {
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class RangeConstraintManager : public RangedConstraintManager {
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public:
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RangeConstraintManager(SubEngine *SE, SValBuilder &SVB)
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: RangedConstraintManager(SE, SVB) {}
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//===------------------------------------------------------------------===//
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// Implementation for interface from ConstraintManager.
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//===------------------------------------------------------------------===//
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bool haveEqualConstraints(ProgramStateRef S1,
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ProgramStateRef S2) const override {
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return S1->get<ConstraintRange>() == S2->get<ConstraintRange>();
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}
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bool canReasonAbout(SVal X) const override;
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ConditionTruthVal checkNull(ProgramStateRef State, SymbolRef Sym) override;
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const llvm::APSInt *getSymVal(ProgramStateRef State,
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SymbolRef Sym) const override;
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ProgramStateRef removeDeadBindings(ProgramStateRef State,
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SymbolReaper &SymReaper) override;
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void printJson(raw_ostream &Out, ProgramStateRef State, const char *NL = "\n",
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unsigned int Space = 0, bool IsDot = false) const override;
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//===------------------------------------------------------------------===//
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// Implementation for interface from RangedConstraintManager.
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//===------------------------------------------------------------------===//
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ProgramStateRef assumeSymNE(ProgramStateRef State, SymbolRef Sym,
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const llvm::APSInt &V,
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const llvm::APSInt &Adjustment) override;
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ProgramStateRef assumeSymEQ(ProgramStateRef State, SymbolRef Sym,
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const llvm::APSInt &V,
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const llvm::APSInt &Adjustment) override;
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ProgramStateRef assumeSymLT(ProgramStateRef State, SymbolRef Sym,
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const llvm::APSInt &V,
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const llvm::APSInt &Adjustment) override;
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ProgramStateRef assumeSymGT(ProgramStateRef State, SymbolRef Sym,
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const llvm::APSInt &V,
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const llvm::APSInt &Adjustment) override;
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ProgramStateRef assumeSymLE(ProgramStateRef State, SymbolRef Sym,
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const llvm::APSInt &V,
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const llvm::APSInt &Adjustment) override;
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ProgramStateRef assumeSymGE(ProgramStateRef State, SymbolRef Sym,
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const llvm::APSInt &V,
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const llvm::APSInt &Adjustment) override;
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ProgramStateRef assumeSymWithinInclusiveRange(
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ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
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const llvm::APSInt &To, const llvm::APSInt &Adjustment) override;
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ProgramStateRef assumeSymOutsideInclusiveRange(
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ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
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const llvm::APSInt &To, const llvm::APSInt &Adjustment) override;
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private:
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RangeSet::Factory F;
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RangeSet getRange(ProgramStateRef State, SymbolRef Sym);
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const RangeSet* getRangeForMinusSymbol(ProgramStateRef State,
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SymbolRef Sym);
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RangeSet getSymLTRange(ProgramStateRef St, SymbolRef Sym,
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const llvm::APSInt &Int,
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const llvm::APSInt &Adjustment);
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RangeSet getSymGTRange(ProgramStateRef St, SymbolRef Sym,
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const llvm::APSInt &Int,
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const llvm::APSInt &Adjustment);
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RangeSet getSymLERange(ProgramStateRef St, SymbolRef Sym,
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const llvm::APSInt &Int,
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const llvm::APSInt &Adjustment);
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RangeSet getSymLERange(llvm::function_ref<RangeSet()> RS,
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const llvm::APSInt &Int,
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const llvm::APSInt &Adjustment);
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RangeSet getSymGERange(ProgramStateRef St, SymbolRef Sym,
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const llvm::APSInt &Int,
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const llvm::APSInt &Adjustment);
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};
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} // end anonymous namespace
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std::unique_ptr<ConstraintManager>
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ento::CreateRangeConstraintManager(ProgramStateManager &StMgr, SubEngine *Eng) {
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return llvm::make_unique<RangeConstraintManager>(Eng, StMgr.getSValBuilder());
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}
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bool RangeConstraintManager::canReasonAbout(SVal X) const {
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Optional<nonloc::SymbolVal> SymVal = X.getAs<nonloc::SymbolVal>();
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if (SymVal && SymVal->isExpression()) {
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const SymExpr *SE = SymVal->getSymbol();
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if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(SE)) {
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switch (SIE->getOpcode()) {
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// We don't reason yet about bitwise-constraints on symbolic values.
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case BO_And:
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case BO_Or:
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case BO_Xor:
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return false;
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// We don't reason yet about these arithmetic constraints on
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// symbolic values.
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case BO_Mul:
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case BO_Div:
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case BO_Rem:
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case BO_Shl:
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case BO_Shr:
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return false;
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// All other cases.
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default:
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return true;
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}
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}
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if (const SymSymExpr *SSE = dyn_cast<SymSymExpr>(SE)) {
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// FIXME: Handle <=> here.
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if (BinaryOperator::isEqualityOp(SSE->getOpcode()) ||
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BinaryOperator::isRelationalOp(SSE->getOpcode())) {
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// We handle Loc <> Loc comparisons, but not (yet) NonLoc <> NonLoc.
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// We've recently started producing Loc <> NonLoc comparisons (that
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// result from casts of one of the operands between eg. intptr_t and
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// void *), but we can't reason about them yet.
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if (Loc::isLocType(SSE->getLHS()->getType())) {
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return Loc::isLocType(SSE->getRHS()->getType());
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}
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}
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}
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return false;
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}
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return true;
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}
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ConditionTruthVal RangeConstraintManager::checkNull(ProgramStateRef State,
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SymbolRef Sym) {
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const RangeSet *Ranges = State->get<ConstraintRange>(Sym);
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// If we don't have any information about this symbol, it's underconstrained.
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if (!Ranges)
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return ConditionTruthVal();
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// If we have a concrete value, see if it's zero.
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if (const llvm::APSInt *Value = Ranges->getConcreteValue())
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return *Value == 0;
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BasicValueFactory &BV = getBasicVals();
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APSIntType IntType = BV.getAPSIntType(Sym->getType());
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llvm::APSInt Zero = IntType.getZeroValue();
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// Check if zero is in the set of possible values.
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if (Ranges->Intersect(BV, F, Zero, Zero).isEmpty())
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return false;
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// Zero is a possible value, but it is not the /only/ possible value.
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return ConditionTruthVal();
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}
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const llvm::APSInt *RangeConstraintManager::getSymVal(ProgramStateRef St,
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SymbolRef Sym) const {
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const ConstraintRangeTy::data_type *T = St->get<ConstraintRange>(Sym);
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return T ? T->getConcreteValue() : nullptr;
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}
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/// Scan all symbols referenced by the constraints. If the symbol is not alive
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/// as marked in LSymbols, mark it as dead in DSymbols.
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ProgramStateRef
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RangeConstraintManager::removeDeadBindings(ProgramStateRef State,
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SymbolReaper &SymReaper) {
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bool Changed = false;
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ConstraintRangeTy CR = State->get<ConstraintRange>();
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ConstraintRangeTy::Factory &CRFactory = State->get_context<ConstraintRange>();
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for (ConstraintRangeTy::iterator I = CR.begin(), E = CR.end(); I != E; ++I) {
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SymbolRef Sym = I.getKey();
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if (SymReaper.isDead(Sym)) {
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Changed = true;
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CR = CRFactory.remove(CR, Sym);
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}
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}
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return Changed ? State->set<ConstraintRange>(CR) : State;
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}
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/// Return a range set subtracting zero from \p Domain.
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static RangeSet assumeNonZero(
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BasicValueFactory &BV,
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RangeSet::Factory &F,
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SymbolRef Sym,
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RangeSet Domain) {
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APSIntType IntType = BV.getAPSIntType(Sym->getType());
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return Domain.Intersect(BV, F, ++IntType.getZeroValue(),
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--IntType.getZeroValue());
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}
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/// Apply implicit constraints for bitwise OR- and AND-.
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/// For unsigned types, bitwise OR with a constant always returns
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/// a value greater-or-equal than the constant, and bitwise AND
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/// returns a value less-or-equal then the constant.
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///
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/// Pattern matches the expression \p Sym against those rule,
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/// and applies the required constraints.
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/// \p Input Previously established expression range set
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static RangeSet applyBitwiseConstraints(
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BasicValueFactory &BV,
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RangeSet::Factory &F,
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RangeSet Input,
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const SymIntExpr* SIE) {
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QualType T = SIE->getType();
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bool IsUnsigned = T->isUnsignedIntegerType();
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const llvm::APSInt &RHS = SIE->getRHS();
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const llvm::APSInt &Zero = BV.getAPSIntType(T).getZeroValue();
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BinaryOperator::Opcode Operator = SIE->getOpcode();
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// For unsigned types, the output of bitwise-or is bigger-or-equal than RHS.
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if (Operator == BO_Or && IsUnsigned)
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return Input.Intersect(BV, F, RHS, BV.getMaxValue(T));
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// Bitwise-or with a non-zero constant is always non-zero.
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if (Operator == BO_Or && RHS != Zero)
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return assumeNonZero(BV, F, SIE, Input);
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// For unsigned types, or positive RHS,
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// bitwise-and output is always smaller-or-equal than RHS (assuming two's
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// complement representation of signed types).
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if (Operator == BO_And && (IsUnsigned || RHS >= Zero))
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return Input.Intersect(BV, F, BV.getMinValue(T), RHS);
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return Input;
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}
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RangeSet RangeConstraintManager::getRange(ProgramStateRef State,
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SymbolRef Sym) {
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ConstraintRangeTy::data_type *V = State->get<ConstraintRange>(Sym);
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// If Sym is a difference of symbols A - B, then maybe we have range set
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// stored for B - A.
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BasicValueFactory &BV = getBasicVals();
|
|
const RangeSet *R = getRangeForMinusSymbol(State, Sym);
|
|
|
|
// If we have range set stored for both A - B and B - A then calculate the
|
|
// effective range set by intersecting the range set for A - B and the
|
|
// negated range set of B - A.
|
|
if (V && R)
|
|
return V->Intersect(BV, F, R->Negate(BV, F));
|
|
if (V)
|
|
return *V;
|
|
if (R)
|
|
return R->Negate(BV, F);
|
|
|
|
// Lazily generate a new RangeSet representing all possible values for the
|
|
// given symbol type.
|
|
QualType T = Sym->getType();
|
|
|
|
RangeSet Result(F, BV.getMinValue(T), BV.getMaxValue(T));
|
|
|
|
// References are known to be non-zero.
|
|
if (T->isReferenceType())
|
|
return assumeNonZero(BV, F, Sym, Result);
|
|
|
|
// Known constraints on ranges of bitwise expressions.
|
|
if (const SymIntExpr* SIE = dyn_cast<SymIntExpr>(Sym))
|
|
return applyBitwiseConstraints(BV, F, Result, SIE);
|
|
|
|
return Result;
|
|
}
|
|
|
|
// FIXME: Once SValBuilder supports unary minus, we should use SValBuilder to
|
|
// obtain the negated symbolic expression instead of constructing the
|
|
// symbol manually. This will allow us to support finding ranges of not
|
|
// only negated SymSymExpr-type expressions, but also of other, simpler
|
|
// expressions which we currently do not know how to negate.
|
|
const RangeSet*
|
|
RangeConstraintManager::getRangeForMinusSymbol(ProgramStateRef State,
|
|
SymbolRef Sym) {
|
|
if (const SymSymExpr *SSE = dyn_cast<SymSymExpr>(Sym)) {
|
|
if (SSE->getOpcode() == BO_Sub) {
|
|
QualType T = Sym->getType();
|
|
SymbolManager &SymMgr = State->getSymbolManager();
|
|
SymbolRef negSym = SymMgr.getSymSymExpr(SSE->getRHS(), BO_Sub,
|
|
SSE->getLHS(), T);
|
|
if (const RangeSet *negV = State->get<ConstraintRange>(negSym)) {
|
|
// Unsigned range set cannot be negated, unless it is [0, 0].
|
|
if ((negV->getConcreteValue() &&
|
|
(*negV->getConcreteValue() == 0)) ||
|
|
T->isSignedIntegerOrEnumerationType())
|
|
return negV;
|
|
}
|
|
}
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
//===------------------------------------------------------------------------===
|
|
// assumeSymX methods: protected interface for RangeConstraintManager.
|
|
//===------------------------------------------------------------------------===/
|
|
|
|
// The syntax for ranges below is mathematical, using [x, y] for closed ranges
|
|
// and (x, y) for open ranges. These ranges are modular, corresponding with
|
|
// a common treatment of C integer overflow. This means that these methods
|
|
// do not have to worry about overflow; RangeSet::Intersect can handle such a
|
|
// "wraparound" range.
|
|
// As an example, the range [UINT_MAX-1, 3) contains five values: UINT_MAX-1,
|
|
// UINT_MAX, 0, 1, and 2.
|
|
|
|
ProgramStateRef
|
|
RangeConstraintManager::assumeSymNE(ProgramStateRef St, SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
// Before we do any real work, see if the value can even show up.
|
|
APSIntType AdjustmentType(Adjustment);
|
|
if (AdjustmentType.testInRange(Int, true) != APSIntType::RTR_Within)
|
|
return St;
|
|
|
|
llvm::APSInt Lower = AdjustmentType.convert(Int) - Adjustment;
|
|
llvm::APSInt Upper = Lower;
|
|
--Lower;
|
|
++Upper;
|
|
|
|
// [Int-Adjustment+1, Int-Adjustment-1]
|
|
// Notice that the lower bound is greater than the upper bound.
|
|
RangeSet New = getRange(St, Sym).Intersect(getBasicVals(), F, Upper, Lower);
|
|
return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
|
|
}
|
|
|
|
ProgramStateRef
|
|
RangeConstraintManager::assumeSymEQ(ProgramStateRef St, SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
// Before we do any real work, see if the value can even show up.
|
|
APSIntType AdjustmentType(Adjustment);
|
|
if (AdjustmentType.testInRange(Int, true) != APSIntType::RTR_Within)
|
|
return nullptr;
|
|
|
|
// [Int-Adjustment, Int-Adjustment]
|
|
llvm::APSInt AdjInt = AdjustmentType.convert(Int) - Adjustment;
|
|
RangeSet New = getRange(St, Sym).Intersect(getBasicVals(), F, AdjInt, AdjInt);
|
|
return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
|
|
}
|
|
|
|
RangeSet RangeConstraintManager::getSymLTRange(ProgramStateRef St,
|
|
SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
// Before we do any real work, see if the value can even show up.
|
|
APSIntType AdjustmentType(Adjustment);
|
|
switch (AdjustmentType.testInRange(Int, true)) {
|
|
case APSIntType::RTR_Below:
|
|
return F.getEmptySet();
|
|
case APSIntType::RTR_Within:
|
|
break;
|
|
case APSIntType::RTR_Above:
|
|
return getRange(St, Sym);
|
|
}
|
|
|
|
// Special case for Int == Min. This is always false.
|
|
llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
|
|
llvm::APSInt Min = AdjustmentType.getMinValue();
|
|
if (ComparisonVal == Min)
|
|
return F.getEmptySet();
|
|
|
|
llvm::APSInt Lower = Min - Adjustment;
|
|
llvm::APSInt Upper = ComparisonVal - Adjustment;
|
|
--Upper;
|
|
|
|
return getRange(St, Sym).Intersect(getBasicVals(), F, Lower, Upper);
|
|
}
|
|
|
|
ProgramStateRef
|
|
RangeConstraintManager::assumeSymLT(ProgramStateRef St, SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
RangeSet New = getSymLTRange(St, Sym, Int, Adjustment);
|
|
return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
|
|
}
|
|
|
|
RangeSet RangeConstraintManager::getSymGTRange(ProgramStateRef St,
|
|
SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
// Before we do any real work, see if the value can even show up.
|
|
APSIntType AdjustmentType(Adjustment);
|
|
switch (AdjustmentType.testInRange(Int, true)) {
|
|
case APSIntType::RTR_Below:
|
|
return getRange(St, Sym);
|
|
case APSIntType::RTR_Within:
|
|
break;
|
|
case APSIntType::RTR_Above:
|
|
return F.getEmptySet();
|
|
}
|
|
|
|
// Special case for Int == Max. This is always false.
|
|
llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
|
|
llvm::APSInt Max = AdjustmentType.getMaxValue();
|
|
if (ComparisonVal == Max)
|
|
return F.getEmptySet();
|
|
|
|
llvm::APSInt Lower = ComparisonVal - Adjustment;
|
|
llvm::APSInt Upper = Max - Adjustment;
|
|
++Lower;
|
|
|
|
return getRange(St, Sym).Intersect(getBasicVals(), F, Lower, Upper);
|
|
}
|
|
|
|
ProgramStateRef
|
|
RangeConstraintManager::assumeSymGT(ProgramStateRef St, SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
RangeSet New = getSymGTRange(St, Sym, Int, Adjustment);
|
|
return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
|
|
}
|
|
|
|
RangeSet RangeConstraintManager::getSymGERange(ProgramStateRef St,
|
|
SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
// Before we do any real work, see if the value can even show up.
|
|
APSIntType AdjustmentType(Adjustment);
|
|
switch (AdjustmentType.testInRange(Int, true)) {
|
|
case APSIntType::RTR_Below:
|
|
return getRange(St, Sym);
|
|
case APSIntType::RTR_Within:
|
|
break;
|
|
case APSIntType::RTR_Above:
|
|
return F.getEmptySet();
|
|
}
|
|
|
|
// Special case for Int == Min. This is always feasible.
|
|
llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
|
|
llvm::APSInt Min = AdjustmentType.getMinValue();
|
|
if (ComparisonVal == Min)
|
|
return getRange(St, Sym);
|
|
|
|
llvm::APSInt Max = AdjustmentType.getMaxValue();
|
|
llvm::APSInt Lower = ComparisonVal - Adjustment;
|
|
llvm::APSInt Upper = Max - Adjustment;
|
|
|
|
return getRange(St, Sym).Intersect(getBasicVals(), F, Lower, Upper);
|
|
}
|
|
|
|
ProgramStateRef
|
|
RangeConstraintManager::assumeSymGE(ProgramStateRef St, SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
RangeSet New = getSymGERange(St, Sym, Int, Adjustment);
|
|
return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
|
|
}
|
|
|
|
RangeSet RangeConstraintManager::getSymLERange(
|
|
llvm::function_ref<RangeSet()> RS,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
// Before we do any real work, see if the value can even show up.
|
|
APSIntType AdjustmentType(Adjustment);
|
|
switch (AdjustmentType.testInRange(Int, true)) {
|
|
case APSIntType::RTR_Below:
|
|
return F.getEmptySet();
|
|
case APSIntType::RTR_Within:
|
|
break;
|
|
case APSIntType::RTR_Above:
|
|
return RS();
|
|
}
|
|
|
|
// Special case for Int == Max. This is always feasible.
|
|
llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
|
|
llvm::APSInt Max = AdjustmentType.getMaxValue();
|
|
if (ComparisonVal == Max)
|
|
return RS();
|
|
|
|
llvm::APSInt Min = AdjustmentType.getMinValue();
|
|
llvm::APSInt Lower = Min - Adjustment;
|
|
llvm::APSInt Upper = ComparisonVal - Adjustment;
|
|
|
|
return RS().Intersect(getBasicVals(), F, Lower, Upper);
|
|
}
|
|
|
|
RangeSet RangeConstraintManager::getSymLERange(ProgramStateRef St,
|
|
SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
return getSymLERange([&] { return getRange(St, Sym); }, Int, Adjustment);
|
|
}
|
|
|
|
ProgramStateRef
|
|
RangeConstraintManager::assumeSymLE(ProgramStateRef St, SymbolRef Sym,
|
|
const llvm::APSInt &Int,
|
|
const llvm::APSInt &Adjustment) {
|
|
RangeSet New = getSymLERange(St, Sym, Int, Adjustment);
|
|
return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
|
|
}
|
|
|
|
ProgramStateRef RangeConstraintManager::assumeSymWithinInclusiveRange(
|
|
ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
|
|
const llvm::APSInt &To, const llvm::APSInt &Adjustment) {
|
|
RangeSet New = getSymGERange(State, Sym, From, Adjustment);
|
|
if (New.isEmpty())
|
|
return nullptr;
|
|
RangeSet Out = getSymLERange([&] { return New; }, To, Adjustment);
|
|
return Out.isEmpty() ? nullptr : State->set<ConstraintRange>(Sym, Out);
|
|
}
|
|
|
|
ProgramStateRef RangeConstraintManager::assumeSymOutsideInclusiveRange(
|
|
ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
|
|
const llvm::APSInt &To, const llvm::APSInt &Adjustment) {
|
|
RangeSet RangeLT = getSymLTRange(State, Sym, From, Adjustment);
|
|
RangeSet RangeGT = getSymGTRange(State, Sym, To, Adjustment);
|
|
RangeSet New(RangeLT.addRange(F, RangeGT));
|
|
return New.isEmpty() ? nullptr : State->set<ConstraintRange>(Sym, New);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Pretty-printing.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
void RangeConstraintManager::printJson(raw_ostream &Out, ProgramStateRef State,
|
|
const char *NL, unsigned int Space,
|
|
bool IsDot) const {
|
|
ConstraintRangeTy Constraints = State->get<ConstraintRange>();
|
|
|
|
Indent(Out, Space, IsDot) << "\"constraints\": ";
|
|
if (Constraints.isEmpty()) {
|
|
Out << "null," << NL;
|
|
return;
|
|
}
|
|
|
|
++Space;
|
|
Out << '[' << NL;
|
|
for (ConstraintRangeTy::iterator I = Constraints.begin();
|
|
I != Constraints.end(); ++I) {
|
|
Indent(Out, Space, IsDot)
|
|
<< "{ \"symbol\": \"" << I.getKey() << "\", \"range\": \"";
|
|
I.getData().print(Out);
|
|
Out << "\" }";
|
|
|
|
if (std::next(I) != Constraints.end())
|
|
Out << ',';
|
|
Out << NL;
|
|
}
|
|
|
|
--Space;
|
|
Indent(Out, Space, IsDot) << "]," << NL;
|
|
}
|