bool trans::hasSideEffects(Expr *E, ASTContext &Ctx) {
if (!E || !E->HasSideEffects(Ctx))
return false;
E = E->IgnoreParenCasts();
ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E);
if (!ME)
return true;
switch (ME->getMethodFamily()) {
case OMF_autorelease:
case OMF_dealloc:
case OMF_release:
case OMF_retain:
switch (ME->getReceiverKind()) {
case ObjCMessageExpr::SuperInstance:
return false;
case ObjCMessageExpr::Instance:
return hasSideEffects(ME->getInstanceReceiver(), Ctx);
default:
break;
}
break;
default:
break;
}
return true;
}
void TransferFunctions::Visit(Stmt *S) {
if (observer)
observer->observeStmt(S, currentBlock, val);
StmtVisitor<TransferFunctions>::Visit(S);
if (isa<Expr>(S)) {
val.liveStmts = LV.SSetFact.remove(val.liveStmts, S);
}
// Mark all children expressions live.
switch (S->getStmtClass()) {
default:
break;
case Stmt::StmtExprClass: {
// For statement expressions, look through the compound statement.
S = cast<StmtExpr>(S)->getSubStmt();
break;
}
case Stmt::CXXMemberCallExprClass: {
// Include the implicit "this" pointer as being live.
CXXMemberCallExpr *CE = cast<CXXMemberCallExpr>(S);
if (Expr *ImplicitObj = CE->getImplicitObjectArgument()) {
AddLiveStmt(val.liveStmts, LV.SSetFact, ImplicitObj);
}
break;
}
case Stmt::ObjCMessageExprClass: {
// In calls to super, include the implicit "self" pointer as being live.
ObjCMessageExpr *CE = cast<ObjCMessageExpr>(S);
if (CE->getReceiverKind() == ObjCMessageExpr::SuperInstance)
val.liveDecls = LV.DSetFact.add(val.liveDecls,
LV.analysisContext.getSelfDecl());
break;
}
case Stmt::DeclStmtClass: {
const DeclStmt *DS = cast<DeclStmt>(S);
if (const VarDecl *VD = dyn_cast<VarDecl>(DS->getSingleDecl())) {
for (const VariableArrayType* VA = FindVA(VD->getType());
VA != nullptr; VA = FindVA(VA->getElementType())) {
AddLiveStmt(val.liveStmts, LV.SSetFact, VA->getSizeExpr());
}
}
break;
}
case Stmt::PseudoObjectExprClass: {
// A pseudo-object operation only directly consumes its result
// expression.
Expr *child = cast<PseudoObjectExpr>(S)->getResultExpr();
if (!child) return;
if (OpaqueValueExpr *OV = dyn_cast<OpaqueValueExpr>(child))
child = OV->getSourceExpr();
child = child->IgnoreParens();
val.liveStmts = LV.SSetFact.add(val.liveStmts, child);
return;
}
// FIXME: These cases eventually shouldn't be needed.
case Stmt::ExprWithCleanupsClass: {
S = cast<ExprWithCleanups>(S)->getSubExpr();
break;
}
case Stmt::CXXBindTemporaryExprClass: {
S = cast<CXXBindTemporaryExpr>(S)->getSubExpr();
break;
}
case Stmt::UnaryExprOrTypeTraitExprClass: {
// No need to unconditionally visit subexpressions.
return;
}
}
for (Stmt *Child : S->children()) {
if (Child)
AddLiveStmt(val.liveStmts, LV.SSetFact, Child);
}
}