ExpressionPtr Expression::unneededHelper() {
ExpressionListPtr elist = ExpressionListPtr
(new ExpressionList(getScope(), getRange(),
ExpressionList::ListKindWrapped));
bool change = false;
for (int i=0, n = getKidCount(); i < n; i++) {
ExpressionPtr kid = getNthExpr(i);
if (kid && kid->getContainedEffects()) {
ExpressionPtr rep = kid->unneeded();
if (rep != kid) change = true;
if (rep->is(Expression::KindOfExpressionList)) {
for (int j=0, m = rep->getKidCount(); j < m; j++) {
elist->addElement(rep->getNthExpr(j));
}
} else {
elist->addElement(rep);
}
}
}
if (change) {
getScope()->addUpdates(BlockScope::UseKindCaller);
}
int n = elist->getCount();
assert(n);
if (n == 1) {
return elist->getNthExpr(0);
} else {
return elist;
}
}
ExpressionPtr AliasManager::canonicalizeRecur(ExpressionPtr e) {
switch (e->getKindOf()) {
case Expression::KindOfQOpExpression:
canonicalizeKid(e, e->getNthExpr(0), 0);
beginScope();
canonicalizeKid(e, e->getNthExpr(1), 1);
resetScope();
canonicalizeKid(e, e->getNthExpr(2), 2);
endScope();
return canonicalizeNode(e);
case Expression::KindOfBinaryOpExpression:
if (spc(BinaryOpExpression,e)->isShortCircuitOperator()) {
canonicalizeKid(e, e->getNthExpr(0), 0);
beginScope();
canonicalizeKid(e, e->getNthExpr(1), 1);
endScope();
return canonicalizeNode(e);
}
break;
default:
break;
}
for (int i = 0, n = e->getKidCount(); i < n; i++) {
canonicalizeKid(e, e->getNthExpr(i), i);
}
return canonicalizeNode(e);
}
void Dictionary::build(ExpressionPtr e) {
for (int i = 0, n = e->getKidCount(); i < n; i++) {
if (ExpressionPtr kid = e->getNthExpr(i)) {
build(kid);
}
}
visit(e);
}
/*
* We can end up with chains of canonPtrs keeping the
* elements of an ExpressionList alive, with the result
* that when they are finally destroyed, they are destroyed
* one by one, recursively.
* This proactively clears them.
*/
static void clearCanonPtrs(ExpressionPtr e) {
e->setCanonPtr(ExpressionPtr{});
for (int i = e->getKidCount(); i--; ) {
ExpressionPtr kid = e->getNthExpr(i);
if (kid && !kid->is(Expression::KindOfExpressionList)) {
clearCanonPtrs(kid);
}
}
}
void DataFlowWalker::processAccessChain(ExpressionPtr e) {
if (!e) return;
if (!e->is(Expression::KindOfObjectPropertyExpression) &&
!e->is(Expression::KindOfArrayElementExpression)) {
return;
}
for (int i = 0, n = e->getKidCount(); i < n; ++i) {
ExpressionPtr kid(e->getNthExpr(i));
if (kid && kid->hasContext(Expression::AccessContext)) {
processAccessChain(kid);
process(kid, true);
break;
}
}
}
/**
* Traverses the expression tree rooted at e and returns true if
* any node in the tree is a simple variable that references a
* name in m_boundVars.
*/
bool CaptureExtractor::dependsOnQueryOnlyState(ExpressionPtr e) {
assert(e != nullptr);
if (e->getKindOf() == Expression::KindOfSimpleVariable) {
auto sv = static_pointer_cast<SimpleVariable>(e);
auto varName = sv->getName();
for (auto &boundVar : m_boundVars) {
if (varName == boundVar) return true;
}
return false;
}
auto numKids = e->getKidCount();
for (int i = 0; i < numKids; i++) {
auto ei = e->getNthExpr(i);
if (ei == nullptr) return false; //Default param
if (dependsOnQueryOnlyState(ei)) return true;
}
return false;
}
static ExpressionPtr cloneForInlineRecur(InlineCloneInfo &info,
ExpressionPtr exp,
const std::string &prefix,
AnalysisResultConstPtr ar,
FunctionScopePtr scope) {
exp->getOriginalScope(); // make sure to cache the original scope
exp->setBlockScope(scope);
for (int i = 0, n = exp->getKidCount(); i < n; i++) {
if (ExpressionPtr k = exp->getNthExpr(i)) {
exp->setNthKid(i, cloneForInlineRecur(info, k, prefix, ar, scope));
}
}
StaticClassName *scn = dynamic_cast<StaticClassName*>(exp.get());
if (scn && scn->isStatic() && !info.staticClass.empty()) {
scn->resolveStatic(info.staticClass);
}
switch (exp->getKindOf()) {
case Expression::KindOfSimpleVariable:
{
SimpleVariablePtr sv(dynamic_pointer_cast<SimpleVariable>(exp));
if (sv->isSuperGlobal()) break;
string name;
if (sv->isThis()) {
if (!info.callWithThis) {
if (!sv->hasContext(Expression::ObjectContext)) {
exp = sv->makeConstant(ar, "null");
} else {
// This will produce the wrong error
// we really want a "throw_fatal" ast node.
exp = sv->makeConstant(ar, "null");
}
break;
}
if (info.localThis.empty()) break;
name = info.localThis;
} else {
name = prefix + sv->getName();
}
SimpleVariablePtr rep(new SimpleVariable(
exp->getScope(), exp->getLocation(), name));
rep->copyContext(sv);
rep->updateSymbol(SimpleVariablePtr());
rep->getSymbol()->setHidden();
// Conservatively set flags to prevent
// the alias manager from getting confused.
// On the next pass, it will correct the values,
// and optimize appropriately.
rep->getSymbol()->setUsed();
rep->getSymbol()->setReferenced();
if (exp->getContext() & (Expression::LValue|
Expression::RefValue|
Expression::RefParameter)) {
info.sepm[name] = rep;
}
exp = rep;
}
break;
case Expression::KindOfObjectMethodExpression:
{
FunctionCallPtr call(
static_pointer_cast<FunctionCall>(exp));
if (call->getFuncScope() == info.func) {
call->setNoInline();
}
break;
}
case Expression::KindOfSimpleFunctionCall:
{
SimpleFunctionCallPtr call(static_pointer_cast<SimpleFunctionCall>(exp));
call->addLateDependencies(ar);
call->setLocalThis(info.localThis);
if (call->getFuncScope() == info.func) {
call->setNoInline();
}
}
default:
break;
}
return exp;
}
void ExprDict::updateAccess(ExpressionPtr e) {
int cls = e->getExprClass();
int eid = e->getCanonID();
e->clearAnticipated();
e->clearAvailable();
// bail on non-canonical expressions
if (!isCanonicalStructure(eid)) {
// but record we saw a type assertion belonging to this block
m_avlTypeAsserts.push_back(eid);
return;
}
if (m_anticipated &&
(cls & Expression::Update ?
!BitOps::get_bit(eid, m_altered) : !e->getLocalEffects())) {
/*
Anticipated can be computed bottom up as we go. But note that we
only know altered for Load/Store expressions.
*/
int i = e->getKidCount();
while (true) {
if (!i--) {
e->setAnticipated();
if (!e->hasContext(Expression::AssignmentLHS)) {
setStructureOps(eid, m_anticipated, true);
}
break;
}
if (ExpressionPtr k = e->getNthExpr(i)) {
if (!isCanonicalStructure(k->getCanonID())) continue;
if (!k->isAnticipated()) {
break;
}
}
}
}
if (m_available) {
/*
Available has to be computed optimistically, because we dont yet
know what is going to be altered between here and the end of the block
So keep a list of the potentially-available accesses (avlAccess), and
for each id, the last potentially-available expression (avlExpr).
For each modifying expression that we process, we remove expressions
from avlAccess, and at the end, we build up the available expressions
bottom up.
*/
if ((cls & (Expression::Store|Expression::Call)) ||
(cls & Expression::Load &&
e->getContext() & (Expression::LValue|
Expression::RefValue|
Expression::UnsetContext|
Expression::DeepReference))) {
bool isLoad;
int depth = 0, effects = 0;
for (int i = 0, n = m_avlAccess.size(); i < n; ) {
ExpressionRawPtr a = m_avlAccess[i];
if (m_am.checkAnyInterf(e, a, isLoad, depth, effects) !=
AliasManager::DisjointAccess) {
int aid = a->getCanonID();
assert(isCanonicalStructure(aid));
if (eid != aid || cls == Expression::Load) {
BitOps::set_bit(aid, m_altered, true);
}
if (!(cls & Expression::Store) ||
a != e->getStoreVariable()) {
a->clearAvailable();
m_avlAccess[i] = m_avlAccess[--n];
m_avlAccess.resize(n);
continue;
}
}
i++;
}
}
if (cls & Expression::Update ||
!e->getContainedEffects()) {
int i = e->getKidCount();
while (true) {
if (!i--) {
e->setAvailable();
if (cls & Expression::Update) {
m_avlAccess.push_back(e);
}
m_avlExpr[eid] = e;
break;
}
if (ExpressionPtr k = e->getNthExpr(i)) {
if (!isCanonicalStructure(k->getCanonID())) continue;
if (!k->isAvailable()) {
break;
}
}
}
}
}
if ((cls & (Expression::Store|Expression::Call)) ||
(cls & Expression::Load &&
e->getContext() & (Expression::LValue|
Expression::RefValue|
Expression::UnsetContext|
Expression::DeepReference))) {
ExpressionPtr cur = m_active, prev;
bool isLoad;
int depth = 0, effects = 0;
while (cur) {
ExpressionPtr next = cur->getCanonLVal();
int cid = cur->getCanonID();
assert(isCanonicalStructure(cid));
if ((cid != eid || cls == Expression::Load) &&
(BitOps::get_bit(cid, m_altered) ||
m_am.checkAnyInterf(e, cur, isLoad, depth, effects) !=
AliasManager::DisjointAccess)) {
BitOps::set_bit(cid, m_altered, true);
if (!prev) {
m_active = next;
} else {
prev->setCanonPtr(next);
}
} else {
prev = cur;
}
cur = next;
}
}
}
