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);
}
/**
* Rewrites the expression rooted in ep so that it is in a form
* that a query processor can evaluate while referencing only
* state that is contained in the query processor or supplied
* to the query processor in the form of arguments to the query.
* For instance, a reference to a local variable in the scope
* containing the query expression will be rewritten into a
* reference to a (synthetic) parameter of the query expression.
* This is similar to the way lambda expressions capture variables
* from their enclosing environment.
* Note that rewriting implies allocating new objects.
* The original construct is not mutated in any way.
* If the original construct is already in the right form, it is
* returned as is.
*/
ExpressionPtr CaptureExtractor::rewrite(ExpressionPtr ep) {
assert(ep != nullptr);
switch (ep->getKindOf()) {
case Expression::KindOfQueryExpression: {
return rewriteQuery(static_pointer_cast<QueryExpression>(ep));
}
case Expression::KindOfSelectClause: {
// leave select clauses alone, another visitor deals with them.
return ep;
}
case Expression::KindOfFromClause:
case Expression::KindOfLetClause:
case Expression::KindOfIntoClause:
case Expression::KindOfWhereClause: {
return rewriteSimpleClause(static_pointer_cast<SimpleQueryClause>(ep));
}
case Expression::KindOfGroupClause:
case Expression::KindOfJoinClause:
case Expression::KindOfOrderbyClause:
case Expression::KindOfOrdering: {
// leave these alone. they are query specific and not parameterizable.
return ep;
}
case Expression::KindOfObjectPropertyExpression: {
return rewriteObjectProperty(
static_pointer_cast<ObjectPropertyExpression>(ep));
}
case Expression::KindOfSimpleFunctionCall: {
return rewriteCall(static_pointer_cast<SimpleFunctionCall>(ep));
}
case Expression::KindOfScalarExpression: {
// Leave scalars alone. If the query processor can't handle them
// rewriting won't help.
return ep;
}
case Expression::KindOfUnaryOpExpression: {
return rewriteUnary(static_pointer_cast<UnaryOpExpression>(ep));
}
case Expression::KindOfBinaryOpExpression: {
return rewriteBinary(static_pointer_cast<BinaryOpExpression>(ep));
}
case Expression::KindOfSimpleVariable: {
return rewriteSimpleVariable(static_pointer_cast<SimpleVariable>(ep));
}
case Expression::KindOfExpressionList: {
return rewriteExpressionList(static_pointer_cast<ExpressionList>(ep));
}
default: {
// If we get here, the expression is not a candidate for evaluation
// by the query processor, so just turn it into a query parameter.
return newQueryParamRef(ep);
}
}
}
/*
Determine whether the rhs behaves normall, or abnormally.
1) If the expression is the silence operator, recurse on the inner expression.
2) If the expression is a list assignment expression, recurse on the
RHS of the expression.
3) If the expression is one of the following, then E behaves normally:
Simple/Dynamic variable (including $this and superglobals)
Array element expression
Property expression
Static variable expression
Function call expression
Preinc/predec expression (but not postinc/postdec)
Assignment expression
Assignment op expression
Binding assignment expression
Include/require expression
Eval expression
Array expression
Array cast expression
4) For all other expressions, E behaves abnormally. This includes:
All binary operator expressions
All unary operator expressions except silence and preinc/predec
Scalar expression of type null, bool, int, double, or string
Qop expression (?:)
Constant expression
Class constant expression
Isset or empty expression
Exit expression
Instanceof expression
*/
static ListAssignment::RHSKind GetRHSKind(ExpressionPtr rhs) {
switch (rhs->getKindOf()) {
case Expression::KindOfSimpleVariable:
case Expression::KindOfDynamicVariable:
case Expression::KindOfArrayElementExpression:
case Expression::KindOfObjectPropertyExpression:
case Expression::KindOfStaticMemberExpression:
case Expression::KindOfSimpleFunctionCall:
case Expression::KindOfDynamicFunctionCall:
case Expression::KindOfObjectMethodExpression:
case Expression::KindOfNewObjectExpression:
case Expression::KindOfAssignmentExpression:
case Expression::KindOfIncludeExpression:
return ListAssignment::Regular;
case Expression::KindOfListAssignment:
return GetRHSKind(static_pointer_cast<ListAssignment>(rhs)->getArray());
case Expression::KindOfUnaryOpExpression: {
UnaryOpExpressionPtr u(static_pointer_cast<UnaryOpExpression>(rhs));
switch (u->getOp()) {
case '@':
return GetRHSKind(u->getExpression());
case T_INC:
case T_DEC:
return u->getFront() ?
ListAssignment::Regular : ListAssignment::Checked;
case T_EVAL:
case T_ARRAY:
case T_ARRAY_CAST:
return ListAssignment::Regular;
default:
return ListAssignment::Null;
}
break;
}
case Expression::KindOfBinaryOpExpression: {
BinaryOpExpressionPtr b(static_pointer_cast<BinaryOpExpression>(rhs));
return b->isAssignmentOp() || b->getOp() == '+' ?
ListAssignment::Regular : ListAssignment::Null;
}
case Expression::KindOfQOpExpression:
return ListAssignment::Checked;
default: break;
}
return ListAssignment::Null;
}
static bool isReadOnlyAccess(ExpressionPtr e) {
if (e->getContext() & (Expression::UnsetContext|
Expression::RefValue|
Expression::LValue)) {
return false;
}
switch (e->getKindOf()) {
case Expression::KindOfConstantExpression:
case Expression::KindOfSimpleVariable:
case Expression::KindOfArrayElementExpression:
case Expression::KindOfDynamicVariable:
return true;
default:
return false;
}
}
/**
* 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;
}
void DataFlowWalker::process(ExpressionPtr e, bool doAccessChains) {
if ((e->getContext() & (Expression::AssignmentLHS|Expression::OprLValue)) ||
(!doAccessChains && e->hasContext(Expression::AccessContext))) {
return;
}
switch (e->getKindOf()) {
case Expression::KindOfListAssignment:
processAccessChainLA(static_pointer_cast<ListAssignment>(e));
processAccess(e);
break;
case Expression::KindOfArrayElementExpression:
case Expression::KindOfObjectPropertyExpression:
if (!e->hasContext(Expression::AccessContext)) {
processAccessChain(e);
}
// fall through
case Expression::KindOfObjectMethodExpression:
case Expression::KindOfDynamicFunctionCall:
case Expression::KindOfSimpleFunctionCall:
case Expression::KindOfNewObjectExpression:
case Expression::KindOfIncludeExpression:
case Expression::KindOfSimpleVariable:
case Expression::KindOfDynamicVariable:
case Expression::KindOfStaticMemberExpression:
case Expression::KindOfConstantExpression:
processAccess(e);
break;
case Expression::KindOfAssignmentExpression:
case Expression::KindOfBinaryOpExpression:
case Expression::KindOfUnaryOpExpression: {
ExpressionPtr var = e->getStoreVariable();
if (var && var->getContext() & (Expression::AssignmentLHS|
Expression::OprLValue)) {
processAccessChain(var);
processAccess(var);
}
// fall through
}
default:
processAccess(e);
break;
}
}
static inline std::string ExtractDocComment(ExpressionPtr e) {
if (!e) return "";
switch (e->getKindOf()) {
case Expression::KindOfAssignmentExpression: {
AssignmentExpressionPtr ae(static_pointer_cast<AssignmentExpression>(e));
return ExtractDocComment(ae->getVariable());
}
case Expression::KindOfSimpleVariable: {
SimpleVariablePtr sv(static_pointer_cast<SimpleVariable>(e));
return sv->getDocComment();
}
case Expression::KindOfConstantExpression: {
ConstantExpressionPtr ce(static_pointer_cast<ConstantExpression>(e));
return ce->getDocComment();
}
default: return "";
}
return "";
}
static inline
std::string ExtractInitializer(AnalysisResultPtr ar, ExpressionPtr e) {
switch (e->getKindOf()) {
case Expression::KindOfParameterExpression:
{
auto p = static_pointer_cast<ParameterExpression>(e);
if (!p->defaultValue()) return "";
return p->defaultValue()->getText(ar);
}
default:
// TODO(stephentu): this doesn't allow us to tell the difference between
// something like:
// class X { public $x; } versus
// class X { public $x = null; }
// we'll just end up treating both cases like the latter
return e->getText(ar);
}
return "";
}
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;
}
/*
Determine whether the rhs behaves normally, or abnormally.
1) If the expression is the silence operator, recurse on the inner expression.
2) If the expression is a list assignment expression, recurse on the
RHS of the expression.
3) If the expression is one of the following, then E behaves normally:
Simple/Dynamic variable (including $this and superglobals)
Array element expression
Property expression
Static variable expression
Function call expression
Preinc/predec expression (but not postinc/postdec)
Assignment expression
Assignment op expression
Binding assignment expression
Include/require expression
Eval expression
Array expression
Array cast expression
4) For all other expressions, E behaves abnormally. This includes:
All binary operator expressions
All unary operator expressions except silence and preinc/predec
Scalar expression of type null, bool, int, double, or string
Qop expression (?:)
Constant expression
Class constant expression
Isset or empty expression
Exit expression
Instanceof expression
Anonymous class expression
*/
static ListAssignment::RHSKind GetRHSKind(ExpressionPtr rhs) {
switch (rhs->getKindOf()) {
case Construct::KindOfSimpleVariable:
case Construct::KindOfDynamicVariable:
case Construct::KindOfArrayElementExpression:
case Construct::KindOfObjectPropertyExpression:
case Construct::KindOfStaticMemberExpression:
case Construct::KindOfSimpleFunctionCall:
case Construct::KindOfDynamicFunctionCall:
case Construct::KindOfObjectMethodExpression:
case Construct::KindOfNewObjectExpression:
case Construct::KindOfAssignmentExpression:
case Construct::KindOfExpressionList:
case Construct::KindOfIncludeExpression:
case Construct::KindOfYieldExpression:
case Construct::KindOfYieldFromExpression:
case Construct::KindOfAwaitExpression:
case Construct::KindOfClassExpression:
return ListAssignment::Regular;
case Construct::KindOfListAssignment:
return GetRHSKind(static_pointer_cast<ListAssignment>(rhs)->getArray());
case Construct::KindOfUnaryOpExpression: {
auto u = static_pointer_cast<UnaryOpExpression>(rhs);
switch (u->getOp()) {
case '@':
return GetRHSKind(u->getExpression());
case T_INC:
case T_DEC:
return u->getFront() ?
ListAssignment::Regular : ListAssignment::Checked;
case T_EVAL:
case T_ARRAY:
case T_ARRAY_CAST:
return ListAssignment::Regular;
default:
return ListAssignment::Null;
}
break;
}
case Construct::KindOfBinaryOpExpression: {
auto b = static_pointer_cast<BinaryOpExpression>(rhs);
if (b->isAssignmentOp() ||
b->getOp() == '+' ||
b->getOp() == T_COLLECTION) {
return ListAssignment::Regular;
}
return ListAssignment::Null;
}
case Construct::KindOfQOpExpression:
case Construct::KindOfNullCoalesceExpression:
return ListAssignment::Checked;
// invalid context
case Construct::KindOfExpression:
case Construct::KindOfArrayPairExpression:
case Construct::KindOfParameterExpression:
case Construct::KindOfModifierExpression:
case Construct::KindOfUserAttribute:
always_assert(false);
// non-arrays
case Construct::KindOfScalarExpression:
case Construct::KindOfConstantExpression:
case Construct::KindOfClassConstantExpression:
case Construct::KindOfEncapsListExpression:
case Construct::KindOfClosureExpression:
return ListAssignment::Null;
#define STATEMENT_CASE(x) case Construct::KindOf##x:
DECLARE_STATEMENT_TYPES(STATEMENT_CASE) {
always_assert(false);
}
#undef STATEMENT_CASE
}
// unreachable for known expression kinds
always_assert(false);
}
void RefDict::updateAccess(ExpressionPtr e) {
always_assert(!e->getScope()->inPseudoMain());
int eid = e->getCanonID();
int context = e->getContext();
if (first_pass) {
if (!e->is(Expression::KindOfSimpleVariable) &&
!e->is(Expression::KindOfDynamicVariable)) return;
e->clearAvailable();
e->clearReferencedValid();
e->clearReferenced();
SimpleVariablePtr ptr(dynamic_pointer_cast<SimpleVariable>(e));
if (ptr && (ptr->isSuperGlobal() || ptr->isThis())) return;
if (e->is(Expression::KindOfSimpleVariable)) {
if (BitOps::get_bit(eid, m_referenced)) {
e->setReferenced();
} else if (!BitOps::get_bit(eid, m_killed)) {
// use as a temp place holder
e->setAvailable();
}
}
}
// let the first pass information propagate for both passes, since
// we need it in both contexts
if (context & Expression::RefAssignmentLHS ||
context & Expression::RefValue ||
context & Expression::RefParameter ||
((context & Expression::Declaration) == Expression::Declaration)) {
if (e->is(Expression::KindOfSimpleVariable)) {
BitOps::set_bit(eid, m_referenced, true);
BitOps::set_bit(eid, m_killed, false);
} else {
// for dynamic variables, we must assume the worst
BitOps::set(size(), m_referenced, -1);
BitOps::set(size(), m_killed, 0);
}
} else if (e->is(Expression::KindOfSimpleVariable) &&
context & Expression::LValue &&
context & Expression::UnsetContext) {
BitOps::set_bit(eid, m_referenced, false);
BitOps::set_bit(eid, m_killed, true);
}
if (first_pass) return;
// now we're on the second pass
if (context & Expression::AssignmentLHS ||
context & Expression::OprLValue) {
// we dealt with this node as a store expression
return;
}
int cls = e->getExprClass();
bool isRhsNeeded = false;
bool canKill = false;
ExpressionPtr lhs;
ExpressionPtr rhs;
if (cls & Expression::Store) {
// we care about two cases here
switch (e->getKindOf()) {
case Expression::KindOfAssignmentExpression:
// $x = ...
{
AssignmentExpressionPtr assign(
static_pointer_cast<AssignmentExpression>(e));
lhs = assign->getVariable();
rhs = assign->getValue();
isRhsNeeded = Expression::CheckNeededRHS(rhs);
canKill = true;
}
break;
case Expression::KindOfBinaryOpExpression:
// $x += ...
{
BinaryOpExpressionPtr binop(
static_pointer_cast<BinaryOpExpression>(e));
if (binop->getOp() == T_PLUS_EQUAL) {
lhs = binop->getExp1();
rhs = binop->getExp2();
isRhsNeeded = Expression::CheckNeededRHS(rhs);
}
}
break;
default:
break;
}
}
bool isLhsSimpleVar = false;
bool isLhsDynamic = false;
bool isRefd = false;
if (lhs) {
isLhsSimpleVar = lhs->is(Expression::KindOfSimpleVariable);
// TODO: can a variable only be simple or dynamic?
// If so, this is un-necessary
isLhsDynamic = lhs->is(Expression::KindOfDynamicVariable);
if (isLhsSimpleVar) {
// clean up the LHS AST
lhs->clearAvailable();
lhs->clearNeeded();
lhs->clearNeededValid();
if (BitOps::get_bit(lhs->getCanonID(), m_obj)) {
lhs->setNeeded();
lhs->setNeededValid();
} else if (!BitOps::get_bit(lhs->getCanonID(), m_noobj)) {
lhs->setAvailable();
}
}
if (lhs->isReferencedValid() && lhs->isReferenced() && isRhsNeeded) {
// could we possibly have modified another referenced variable?
isRefd = true;
}
if (isLhsSimpleVar && isRhsNeeded) {
// we see this case:
// $x = new ...
// so we mark $x as being needed
BitOps::set_bit(lhs->getCanonID(), m_obj, true);
BitOps::set_bit(lhs->getCanonID(), m_noobj, false);
} else if (isLhsSimpleVar && canKill && !isRhsNeeded) {
// we saw an assignment that was of the form
// $x = <primitive>
// we can now set $x to be not an object
BitOps::set_bit(lhs->getCanonID(), m_obj, false);
BitOps::set_bit(lhs->getCanonID(), m_noobj, true);
}
}
if (isLhsDynamic && isRhsNeeded) {
// in this case, we must set EVERY variable to contain an object
BitOps::set(size(), m_obj, -1 /* true for each bit */);
BitOps::set(size(), m_noobj, 0 /* false for each bit */);
// we're done, since it can be no worse (no more conservative) than this
return;
}
// do we see a load which could cause the value of this expr to be changed?
// for example:
// function foo(&$x) { $x = 10; }
// $x = 30;
// foo($x); /* <-- this is what we care about */
if ((cls & (Expression::Load|Expression::Call)) &&
(context & (Expression::RefValue|Expression::DeepReference))) {
isRefd = true;
}
// we want to propagate this information to other simple vars we see
if (e->is(Expression::KindOfSimpleVariable)) {
// clean up the AST
e->clearAvailable();
e->clearNeeded();
e->clearNeededValid();
SimpleVariablePtr svp(static_pointer_cast<SimpleVariable>(e));
if (svp->isSuperGlobal() || svp->isThis()) return;
// update the AST to *before* the modification
if (BitOps::get_bit(eid, m_obj)) {
e->setNeeded();
e->setNeededValid();
} else if (!BitOps::get_bit(eid, m_noobj)) {
// use as a temp place holder
e->setAvailable();
}
if (context & Expression::LValue &&
context & Expression::UnsetContext) {
always_assert(!isRefd);
// unset($x);
BitOps::set_bit(eid, m_obj, false);
BitOps::set_bit(eid, m_noobj, true);
} else if (isRefd ||
((context & Expression::Declaration) == Expression::Declaration)) {
// if a simple variable has isRefd, then we need to mark it
// as potentially containing an object.
// also, if the simple variable is in global context
// then we also mark it as potentially containing an object
BitOps::set_bit(eid, m_obj, true);
BitOps::set_bit(eid, m_noobj, false);
}
}
if (isRefd) {
// do a scan for every simple variable referenced value
// in the dictionary and mark it as potentially
// containing an object (in the bit vector)
for (int i = size(); i--; ) {
if (ExpressionPtr e = get(i)) {
always_assert(e->is(Expression::KindOfSimpleVariable));
always_assert(((unsigned int)i) == e->getCanonID());
if (BitOps::get_bit(i, m_referenced)) {
BitOps::set_bit(i, m_obj, true);
BitOps::set_bit(i, m_noobj, false);
}
}
}
}
}
/*
Determine whether the rhs behaves normally, or abnormally.
1) If the expression is the silence operator, recurse on the inner expression.
2) If the expression is a list assignment expression, recurse on the
RHS of the expression.
3) If the expression is one of the following, then E behaves normally:
Simple/Dynamic variable (including $this and superglobals)
Array element expression
Property expression
Static variable expression
Function call expression
Preinc/predec expression (but not postinc/postdec)
Assignment expression
Assignment op expression
Binding assignment expression
Include/require expression
Eval expression
Array expression
Array cast expression
4) For all other expressions, E behaves abnormally. This includes:
All binary operator expressions
All unary operator expressions except silence and preinc/predec
Scalar expression of type null, bool, int, double, or string
Qop expression (?:)
Constant expression
Class constant expression
Isset or empty expression
Exit expression
Instanceof expression
*/
static ListAssignment::RHSKind GetRHSKind(ExpressionPtr rhs) {
switch (rhs->getKindOf()) {
case Expression::KindOfSimpleVariable:
case Expression::KindOfDynamicVariable:
case Expression::KindOfArrayElementExpression:
case Expression::KindOfObjectPropertyExpression:
case Expression::KindOfStaticMemberExpression:
case Expression::KindOfSimpleFunctionCall:
case Expression::KindOfDynamicFunctionCall:
case Expression::KindOfObjectMethodExpression:
case Expression::KindOfNewObjectExpression:
case Expression::KindOfAssignmentExpression:
case Expression::KindOfExpressionList:
case Expression::KindOfIncludeExpression:
case Expression::KindOfYieldExpression:
case Expression::KindOfAwaitExpression:
case Expression::KindOfQueryExpression:
return ListAssignment::Regular;
case Expression::KindOfListAssignment:
return GetRHSKind(static_pointer_cast<ListAssignment>(rhs)->getArray());
case Expression::KindOfUnaryOpExpression: {
UnaryOpExpressionPtr u(static_pointer_cast<UnaryOpExpression>(rhs));
switch (u->getOp()) {
case '@':
return GetRHSKind(u->getExpression());
case T_INC:
case T_DEC:
return u->getFront() ?
ListAssignment::Regular : ListAssignment::Checked;
case T_EVAL:
case T_ARRAY:
case T_ARRAY_CAST:
return ListAssignment::Regular;
default:
return ListAssignment::Null;
}
break;
}
case Expression::KindOfBinaryOpExpression: {
BinaryOpExpressionPtr b(static_pointer_cast<BinaryOpExpression>(rhs));
if (b->isAssignmentOp() ||
b->getOp() == '+' ||
b->getOp() == T_COLLECTION) {
return ListAssignment::Regular;
}
return ListAssignment::Null;
}
case Expression::KindOfQOpExpression:
return ListAssignment::Checked;
// invalid context
case Expression::KindOfArrayPairExpression:
case Expression::KindOfParameterExpression:
case Expression::KindOfModifierExpression:
case Expression::KindOfUserAttribute:
case Expression::KindOfFromClause:
case Expression::KindOfLetClause:
case Expression::KindOfWhereClause:
case Expression::KindOfSelectClause:
case Expression::KindOfIntoClause:
case Expression::KindOfJoinClause:
case Expression::KindOfGroupClause:
case Expression::KindOfOrderbyClause:
case Expression::KindOfOrdering:
always_assert(false);
// non-arrays
case Expression::KindOfScalarExpression:
case Expression::KindOfConstantExpression:
case Expression::KindOfClassConstantExpression:
case Expression::KindOfEncapsListExpression:
case Expression::KindOfClosureExpression:
return ListAssignment::Null;
}
// unreachable for known expression kinds
always_assert(false);
}
ExpressionPtr AliasManager::canonicalizeNode(ExpressionPtr e) {
e->setCanonPtr(ExpressionPtr());
e->setCanonID(0);
switch (e->getKindOf()) {
case Expression::KindOfObjectMethodExpression:
case Expression::KindOfDynamicFunctionCall:
case Expression::KindOfSimpleFunctionCall:
case Expression::KindOfNewObjectExpression:
add(m_bucketMap[0], e);
break;
case Expression::KindOfListAssignment:
add(m_bucketMap[0], e);
break;
case Expression::KindOfAssignmentExpression: {
AssignmentExpressionPtr ae = spc(AssignmentExpression,e);
if (e->getContext() & Expression::DeadStore) {
Construct::recomputeEffects();
return ae->getValue();
}
ExpressionPtr rep;
int interf = findInterf(ae->getVariable(), false, rep);
if (interf == SameAccess) {
switch (rep->getKindOf()) {
default:
break;
case Expression::KindOfAssignmentExpression:
{
AssignmentExpressionPtr a = spc(AssignmentExpression, rep);
ExpressionPtr value = a->getValue();
if (a->getValue()->getContext() & Expression::RefValue) {
break;
}
}
case Expression::KindOfUnaryOpExpression:
case Expression::KindOfBinaryOpExpression:
rep->setContext(Expression::DeadStore);
break;
}
}
add(m_bucketMap[0], e);
break;
}
case Expression::KindOfConstantExpression:
case Expression::KindOfSimpleVariable:
case Expression::KindOfDynamicVariable:
case Expression::KindOfArrayElementExpression:
case Expression::KindOfObjectPropertyExpression:
case Expression::KindOfStaticMemberExpression:
if (!(e->getContext() & (Expression::AssignmentLHS|
Expression::DeepAssignmentLHS|
Expression::OprLValue))) {
if (!(e->getContext() & (Expression::LValue|
Expression::RefValue|
Expression::RefParameter|
Expression::UnsetContext))) {
ExpressionPtr rep;
int interf = findInterf(e, true, rep);
if (interf == SameAccess) {
if (rep->getKindOf() == e->getKindOf()) {
e->setCanonID(rep->getCanonID());
e->setCanonPtr(rep);
return ExpressionPtr();
}
if (rep->getKindOf() == Expression::KindOfAssignmentExpression) {
ExpressionPtr rhs = spc(AssignmentExpression,rep)->getValue();
if (rhs->is(Expression::KindOfScalarExpression)) {
rhs = rhs->clone();
getCanonical(rhs);
return rhs;
}
e->setCanonPtr(rhs);
}
}
}
add(m_bucketMap[0], e);
} else {
getCanonical(e);
}
break;
case Expression::KindOfBinaryOpExpression: {
BinaryOpExpressionPtr bop = spc(BinaryOpExpression, e);
int rop = getOpForAssignmentOp(bop->getOp());
if (rop) {
ExpressionPtr lhs = bop->getExp1();
ExpressionPtr rep;
if (bop->getContext() & Expression::DeadStore) {
Construct::recomputeEffects();
ExpressionPtr rhs = bop->getExp2()->clone();
lhs = lhs->clone();
lhs->clearContext(Expression::LValue);
lhs->clearContext(Expression::NoLValueWrapper);
lhs->clearContext(Expression::OprLValue);
rep = ExpressionPtr
(new BinaryOpExpression(e->getLocation(),
Expression::KindOfBinaryOpExpression,
lhs, rhs, rop));
} else {
ExpressionPtr alt;
int interf = findInterf(lhs, true, alt);
if (interf == SameAccess &&
alt->is(Expression::KindOfAssignmentExpression)) {
ExpressionPtr op0 = spc(AssignmentExpression,alt)->getValue();
if (op0->is(Expression::KindOfScalarExpression)) {
ExpressionPtr op1 = bop->getExp2();
ExpressionPtr rhs
(new BinaryOpExpression(e->getLocation(),
Expression::KindOfBinaryOpExpression,
op0->clone(), op1->clone(), rop));
lhs = lhs->clone();
lhs->clearContext(Expression::OprLValue);
rep = ExpressionPtr
(new AssignmentExpression(e->getLocation(),
Expression::KindOfAssignmentExpression,
lhs, rhs, false));
}
}
}
if (rep) {
ExpressionPtr c = canonicalizeRecur(rep);
return c ? c : rep;
}
add(m_bucketMap[0], e);
} else {
getCanonical(e);
}
break;
}
case Expression::KindOfUnaryOpExpression:
{
UnaryOpExpressionPtr uop = spc(UnaryOpExpression, e);
switch (uop->getOp()) {
case T_INC:
case T_DEC:
if (uop->getContext() & Expression::DeadStore) {
Construct::recomputeEffects();
ExpressionPtr val = uop->getExpression()->clone();
val->clearContext(Expression::LValue);
val->clearContext(Expression::NoLValueWrapper);
val->clearContext(Expression::OprLValue);
if (uop->getFront()) {
ExpressionPtr inc
(new ScalarExpression(uop->getLocation(),
Expression::KindOfScalarExpression,
T_LNUMBER, string("1")));
val = ExpressionPtr
(new BinaryOpExpression(uop->getLocation(),
Expression::KindOfBinaryOpExpression,
val, inc,
uop->getOp() == T_INC ? '+' : '-'));
}
ExpressionPtr r = canonicalizeRecur(val);
return r ? r : val;
}
add(m_bucketMap[0], e);
break;
default:
getCanonical(e);
break;
}
break;
}
default:
getCanonical(e);
break;
}
return ExpressionPtr();
}
int AliasManager::findInterf(ExpressionPtr rv, bool isLoad,
ExpressionPtr &rep) {
BucketMapEntry lvs = m_bucketMap[0];
rep = ExpressionPtr();
ExpressionPtrList::reverse_iterator it = lvs.rbegin(), end = lvs.rend();
int a;
int depth = 0, min_depth = 0, max_depth = 0;
while (it != end) {
ExpressionPtr e = *it++;
switch (e->getKindOf()) {
case Expression::KindOfScalarExpression:
{
ScalarExpressionPtr se = spc(ScalarExpression, e);
const std::string &s = se->getString();
if (s == "begin") {
depth--;
if (depth < min_depth) min_depth = depth;
} else if (s == "end") {
depth++;
if (depth > max_depth) max_depth = depth;
} else {
assert(false);
}
}
break;
case Expression::KindOfObjectMethodExpression:
case Expression::KindOfDynamicFunctionCall:
case Expression::KindOfSimpleFunctionCall:
case Expression::KindOfNewObjectExpression:
return testAccesses(rv, e);
case Expression::KindOfListAssignment: {
ListAssignmentPtr la = spc(ListAssignment, e);
ExpressionList &lhs = *la->getVariables().get();
for (int i = lhs.getCount(); i--; ) {
ExpressionPtr ep = lhs[i];
if (ep && testAccesses(ep, rv) != DisjointAccess) {
return InterfAccess;
}
}
break;
}
case Expression::KindOfObjectPropertyExpression:
case Expression::KindOfConstantExpression:
case Expression::KindOfSimpleVariable:
case Expression::KindOfDynamicVariable:
case Expression::KindOfArrayElementExpression:
case Expression::KindOfStaticMemberExpression:
a = testAccesses(e, rv);
if (a == DisjointAccess) {
continue;
}
if (a == SameAccess) {
if (isLoad) {
// The value of an earlier load is available
// if it dominates this one
if (depth > min_depth) {
a = InterfAccess;
}
} else {
// The assignment definitely hits the load
// if it post-dominates it.
if (min_depth < 0) {
a = InterfAccess;
}
}
}
if (a != SameAccess &&
isLoad && isReadOnlyAccess(e)) {
continue;
}
rep = e;
return a;
case Expression::KindOfUnaryOpExpression:
a = testAccesses(spc(UnaryOpExpression,e)->getExpression(), rv);
goto handle_assign;
case Expression::KindOfBinaryOpExpression:
a = testAccesses(spc(BinaryOpExpression,e)->getExp1(), rv);
goto handle_assign;
case Expression::KindOfAssignmentExpression:
a = testAccesses(spc(AssignmentExpression,e)->getVariable(), rv);
goto handle_assign;
handle_assign:
if (a == DisjointAccess) {
continue;
}
rep = e;
if (a == SameAccess) {
if (isLoad) {
// we can propagate the value of an assignment
// to a load, provided the assignment dominates
// the load.
if (depth > min_depth) {
a = InterfAccess;
}
} else {
// a later assignment kills an earlier one
// provided the later one post-dominates the earlier
if (min_depth < 0) {
a = InterfAccess;
}
}
}
return a;
default:
break;
}
}
return DisjointAccess;
}
int AliasManager::testAccesses(ExpressionPtr e1, ExpressionPtr e2) {
Expression::KindOf k1 = e1->getKindOf(), k2 = e2->getKindOf();
while (true) {
switch (k1) {
case Expression::KindOfConstantExpression:
if (e1->canonCompare(e2)) return SameAccess;
switch (k2) {
case Expression::KindOfObjectMethodExpression:
case Expression::KindOfDynamicFunctionCall:
case Expression::KindOfSimpleFunctionCall:
case Expression::KindOfNewObjectExpression:
return InterfAccess;
default:
return DisjointAccess;
}
break;
case Expression::KindOfArrayElementExpression:
if (k2 == Expression::KindOfSimpleVariable ||
k2 == Expression::KindOfDynamicVariable ||
k2 == Expression::KindOfConstantExpression) {
break;
}
return e1->canonCompare(e2) ?
SameAccess : InterfAccess;
case Expression::KindOfStaticMemberExpression:
if (k2 == Expression::KindOfSimpleVariable ||
k2 == Expression::KindOfConstantExpression) {
break;
}
return e1->canonCompare(e2) ?
SameAccess : InterfAccess;
case Expression::KindOfObjectPropertyExpression:
if (k2 == Expression::KindOfSimpleVariable ||
k2 == Expression::KindOfConstantExpression) {
break;
}
return InterfAccess;
case Expression::KindOfDynamicVariable:
if (k2 == Expression::KindOfSimpleVariable ||
k2 == Expression::KindOfConstantExpression) {
break;
}
return e1->canonCompare(e2) ?
SameAccess : InterfAccess;
case Expression::KindOfSimpleVariable:
{
if (k2 == Expression::KindOfConstantExpression) {
return DisjointAccess;
}
SimpleVariablePtr sv1 = spc(SimpleVariable, e1);
AliasInfo &ai1 = m_aliasInfo[sv1->getName()];
switch (k2) {
case Expression::KindOfSimpleVariable:
{
SimpleVariablePtr sv2 = spc(SimpleVariable, e2);
if (sv1->getName() == sv2->getName()) {
return SameAccess;
}
AliasInfo &ai2 = m_aliasInfo[sv2->getName()];
if (ai1.getIsRefTo() || ai1.getIsGlobal()) {
return m_wildRefs || ai2.getIsGlobal() || ai2.checkRefLevel(0) ?
InterfAccess : DisjointAccess;
}
if (ai2.getIsRefTo() || ai2.getIsGlobal()) {
return m_wildRefs || ai1.getIsGlobal() || ai1.checkRefLevel(0) ?
InterfAccess : DisjointAccess;
}
}
return DisjointAccess;
case Expression::KindOfDynamicVariable:
return InterfAccess;
case Expression::KindOfArrayElementExpression:
if (ai1.getIsRefTo() || ai1.getIsGlobal() ||
m_wildRefs || ai1.checkRefLevel(0)) {
return InterfAccess;
} else {
// $a = "foo"; $a[0] = "x";
ExpressionPtr var = spc(ArrayElementExpression, e2)->getVariable();
if (e1->canonCompare(var)) {
return InterfAccess;
}
}
return DisjointAccess;
case Expression::KindOfStaticMemberExpression:
case Expression::KindOfObjectPropertyExpression:
default:
if (ai1.getIsRefTo() || ai1.getIsGlobal() || m_wildRefs) {
return InterfAccess;
}
return DisjointAccess;
}
// mustnt get here (we would loop forever).
ASSERT(false);
}
default:
return InterfAccess;
}
ExpressionPtr t = e1;
e1 = e2;
e2 = t;
k1 = k2;
k2 = e2->getKindOf();
}
}
