/// ScanReachableFromBlock - Mark all blocks reachable from Start.
/// Returns the total number of blocks that were marked reachable.
unsigned ScanReachableFromBlock(const CFGBlock &Start,
llvm::BitVector &Reachable) {
unsigned count = 0;
llvm::SmallVector<const CFGBlock*, 32> WL;
// Prep work queue
Reachable.set(Start.getBlockID());
++count;
WL.push_back(&Start);
// Find the reachable blocks from 'Start'.
CFGBlock::FilterOptions FO;
FO.IgnoreDefaultsWithCoveredEnums = 1;
while (!WL.empty()) {
const CFGBlock *item = WL.back();
WL.pop_back();
// Look at the successors and mark then reachable.
for (CFGBlock::filtered_succ_iterator I= item->filtered_succ_start_end(FO);
I.hasMore(); ++I)
if (const CFGBlock *B = *I) {
unsigned blockID = B->getBlockID();
if (!Reachable[blockID]) {
Reachable.set(blockID);
++count;
WL.push_back(B);
}
}
}
return count;
}
size_t randomBit(const llvm::BitVector &Vector) {
assert(Vector.any());
auto Itr = Vector.set_bits_begin();
for (size_t I = randomIndex(Vector.count()); I != 0; --I)
++Itr;
return *Itr;
}
static SourceLocation MarkLiveTop(const CFGBlock *Start,
llvm::BitVector &reachable,
SourceManager &SM) {
// Prep work worklist.
llvm::SmallVector<const CFGBlock*, 32> WL;
WL.push_back(Start);
SourceRange R1, R2;
SourceLocation top = GetUnreachableLoc(*Start, R1, R2);
bool FromMainFile = false;
bool FromSystemHeader = false;
bool TopValid = false;
if (top.isValid()) {
FromMainFile = SM.isFromMainFile(top);
FromSystemHeader = SM.isInSystemHeader(top);
TopValid = true;
}
// Solve
CFGBlock::FilterOptions FO;
FO.IgnoreDefaultsWithCoveredEnums = 1;
while (!WL.empty()) {
const CFGBlock *item = WL.back();
WL.pop_back();
SourceLocation c = GetUnreachableLoc(*item, R1, R2);
if (c.isValid()
&& (!TopValid
|| (SM.isFromMainFile(c) && !FromMainFile)
|| (FromSystemHeader && !SM.isInSystemHeader(c))
|| SM.isBeforeInTranslationUnit(c, top))) {
top = c;
FromMainFile = SM.isFromMainFile(top);
FromSystemHeader = SM.isInSystemHeader(top);
}
reachable.set(item->getBlockID());
for (CFGBlock::filtered_succ_iterator I =
item->filtered_succ_start_end(FO); I.hasMore(); ++I)
if (const CFGBlock *B = *I) {
unsigned blockID = B->getBlockID();
if (!reachable[blockID]) {
reachable.set(blockID);
WL.push_back(B);
}
}
}
return top;
}
unsigned ScanReachableFromBlock(const CFGBlock *Start,
llvm::BitVector &Reachable) {
unsigned count = 0;
// Prep work queue
SmallVector<const CFGBlock*, 32> WL;
// The entry block may have already been marked reachable
// by the caller.
if (!Reachable[Start->getBlockID()]) {
++count;
Reachable[Start->getBlockID()] = true;
}
WL.push_back(Start);
// Find the reachable blocks from 'Start'.
while (!WL.empty()) {
const CFGBlock *item = WL.pop_back_val();
// Look at the successors and mark then reachable.
for (CFGBlock::const_succ_iterator I = item->succ_begin(),
E = item->succ_end(); I != E; ++I)
if (const CFGBlock *B = *I) {
unsigned blockID = B->getBlockID();
if (!Reachable[blockID]) {
Reachable.set(blockID);
WL.push_back(B);
++count;
}
}
}
return count;
}
void RegisterAliasingTracker::FillOriginAndAliasedBits(
const llvm::MCRegisterInfo &RegInfo, const llvm::BitVector &SourceBits) {
using RegAliasItr = llvm::MCRegAliasIterator;
for (const size_t PhysReg : SourceBits.set_bits()) {
for (auto Itr = RegAliasItr(PhysReg, &RegInfo, true); Itr.isValid();
++Itr) {
AliasedBits.set(*Itr);
Origins[*Itr] = PhysReg;
}
}
}
llvm::BitVector getAliasedBits(const llvm::MCRegisterInfo &RegInfo,
const llvm::BitVector &SourceBits) {
llvm::BitVector AliasedBits(RegInfo.getNumRegs());
for (const size_t PhysReg : SourceBits.set_bits()) {
using RegAliasItr = llvm::MCRegAliasIterator;
for (auto Itr = RegAliasItr(PhysReg, &RegInfo, true); Itr.isValid();
++Itr) {
AliasedBits.set(*Itr);
}
}
return AliasedBits;
}
static void randomize(const Instruction &Instr, const Variable &Var,
llvm::MCOperand &AssignedValue,
const llvm::BitVector &ForbiddenRegs) {
const Operand &Op = Instr.getPrimaryOperand(Var);
switch (Op.getExplicitOperandInfo().OperandType) {
case llvm::MCOI::OperandType::OPERAND_IMMEDIATE:
// FIXME: explore immediate values too.
AssignedValue = llvm::MCOperand::createImm(1);
break;
case llvm::MCOI::OperandType::OPERAND_REGISTER: {
assert(Op.isReg());
auto AllowedRegs = Op.getRegisterAliasing().sourceBits();
assert(AllowedRegs.size() == ForbiddenRegs.size());
for (auto I : ForbiddenRegs.set_bits())
AllowedRegs.reset(I);
AssignedValue = llvm::MCOperand::createReg(randomBit(AllowedRegs));
break;
}
default:
break;
}
}
static unsigned scanFromBlock(const CFGBlock *Start,
llvm::BitVector &Reachable,
Preprocessor *PP,
bool IncludeSometimesUnreachableEdges) {
unsigned count = 0;
// Prep work queue
SmallVector<const CFGBlock*, 32> WL;
// The entry block may have already been marked reachable
// by the caller.
if (!Reachable[Start->getBlockID()]) {
++count;
Reachable[Start->getBlockID()] = true;
}
WL.push_back(Start);
// Find the reachable blocks from 'Start'.
while (!WL.empty()) {
const CFGBlock *item = WL.pop_back_val();
// There are cases where we want to treat all successors as reachable.
// The idea is that some "sometimes unreachable" code is not interesting,
// and that we should forge ahead and explore those branches anyway.
// This allows us to potentially uncover some "always unreachable" code
// within the "sometimes unreachable" code.
// Look at the successors and mark then reachable.
Optional<bool> TreatAllSuccessorsAsReachable;
if (!IncludeSometimesUnreachableEdges)
TreatAllSuccessorsAsReachable = false;
for (CFGBlock::const_succ_iterator I = item->succ_begin(),
E = item->succ_end(); I != E; ++I) {
const CFGBlock *B = *I;
if (!B) do {
const CFGBlock *UB = I->getPossiblyUnreachableBlock();
if (!UB)
break;
if (!TreatAllSuccessorsAsReachable.hasValue()) {
assert(PP);
TreatAllSuccessorsAsReachable =
shouldTreatSuccessorsAsReachable(item, *PP);
}
if (TreatAllSuccessorsAsReachable.getValue()) {
B = UB;
break;
}
}
while (false);
if (B) {
unsigned blockID = B->getBlockID();
if (!Reachable[blockID]) {
Reachable.set(blockID);
WL.push_back(B);
++count;
}
}
}
}
return count;
}
bool BlockState::isTrackingLSLocation(llvm::BitVector &BV, unsigned i) {
return BV.test(i);
}
void BlockState::stopTrackingLocation(llvm::BitVector &BV, unsigned i) {
BV.reset(i);
}
static void remove(llvm::BitVector &a, const llvm::BitVector &b) {
assert(a.size() == b.size());
for (auto I : b.set_bits())
a.reset(I);
}
