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use crate::ir::*;
use crate::map::IdHashSet;
use crate::{ActiveDataLocation, Data, DataId, DataKind, Element, ExportItem, Function, InitExpr};
use crate::{FunctionId, FunctionKind, Global, GlobalId};
use crate::{GlobalKind, ImportKind, Memory, MemoryId, Table, TableId};
use crate::{Module, TableKind, Type, TypeId};
#[derive(Debug, Default)]
pub struct Roots {
tables: Vec<TableId>,
funcs: Vec<FunctionId>,
globals: Vec<GlobalId>,
memories: Vec<MemoryId>,
datas: Vec<DataId>,
used: Used,
}
impl Roots {
pub fn new() -> Roots {
Roots::default()
}
pub fn push_func(&mut self, func: FunctionId) -> &mut Roots {
if self.used.funcs.insert(func) {
log::trace!("function is used: {:?}", func);
self.funcs.push(func);
}
self
}
pub fn push_table(&mut self, table: TableId) -> &mut Roots {
if self.used.tables.insert(table) {
log::trace!("table is used: {:?}", table);
self.tables.push(table);
}
self
}
pub fn push_memory(&mut self, memory: MemoryId) -> &mut Roots {
if self.used.memories.insert(memory) {
log::trace!("memory is used: {:?}", memory);
self.memories.push(memory);
}
self
}
pub fn push_global(&mut self, global: GlobalId) -> &mut Roots {
if self.used.globals.insert(global) {
log::trace!("global is used: {:?}", global);
self.globals.push(global);
}
self
}
fn push_data(&mut self, data: DataId) -> &mut Roots {
if self.used.data.insert(data) {
log::trace!("data is used: {:?}", data);
self.datas.push(data);
}
self
}
}
#[derive(Debug, Default)]
pub struct Used {
pub tables: IdHashSet<Table>,
pub types: IdHashSet<Type>,
pub funcs: IdHashSet<Function>,
pub globals: IdHashSet<Global>,
pub memories: IdHashSet<Memory>,
pub elements: IdHashSet<Element>,
pub data: IdHashSet<Data>,
}
impl Used {
pub fn new(module: &Module) -> Used {
log::debug!("starting to calculate used set");
let mut stack = Roots::default();
for export in module.exports.iter() {
match export.item {
ExportItem::Function(f) => stack.push_func(f),
ExportItem::Table(t) => stack.push_table(t),
ExportItem::Memory(m) => stack.push_memory(m),
ExportItem::Global(g) => stack.push_global(g),
};
}
if let Some(f) = module.start {
stack.push_func(f);
}
for import in module.imports.iter() {
match import.kind {
ImportKind::Memory(m) => {
let mem = module.memories.get(m);
if !mem.data_segments.is_empty() {
stack.push_memory(m);
}
}
ImportKind::Table(t) => {
let table = module.tables.get(t);
match &table.kind {
TableKind::Function(init) => {
if !init.elements.is_empty() || !init.relative_elements.is_empty() {
stack.push_table(t);
}
}
TableKind::Anyref(_) => {}
}
}
_ => {}
}
}
for (_id, section) in module.customs.iter() {
section.add_gc_roots(&mut stack);
}
while stack.funcs.len() > 0
|| stack.tables.len() > 0
|| stack.memories.len() > 0
|| stack.globals.len() > 0
|| stack.datas.len() > 0
{
while let Some(f) = stack.funcs.pop() {
let func = module.funcs.get(f);
stack.used.types.insert(func.ty());
match &func.kind {
FunctionKind::Local(func) => {
let mut visitor = UsedVisitor { stack: &mut stack };
dfs_in_order(&mut visitor, func, func.entry_block());
}
FunctionKind::Import(_) => {}
FunctionKind::Uninitialized(_) => unreachable!(),
}
}
while let Some(t) = stack.tables.pop() {
match &module.tables.get(t).kind {
TableKind::Function(list) => {
for id in list.elements.iter() {
if let Some(id) = id {
stack.push_func(*id);
}
}
for (global, list) in list.relative_elements.iter() {
stack.push_global(*global);
for id in list {
if let Some(id) = *id {
stack.push_func(id);
}
}
}
}
TableKind::Anyref(_) => {}
}
}
while let Some(t) = stack.globals.pop() {
match &module.globals.get(t).kind {
GlobalKind::Import(_) => {}
GlobalKind::Local(InitExpr::Global(global)) => {
stack.push_global(*global);
}
GlobalKind::Local(InitExpr::Value(_)) => {}
}
}
while let Some(t) = stack.memories.pop() {
for data in &module.memories.get(t).data_segments {
stack.push_data(*data);
}
}
while let Some(d) = stack.datas.pop() {
let d = module.data.get(d);
if let DataKind::Active(ref a) = d.kind {
stack.push_memory(a.memory);
if let ActiveDataLocation::Relative(g) = a.location {
stack.push_global(g);
}
}
}
}
stack.used
}
}
struct UsedVisitor<'a> {
stack: &'a mut Roots,
}
impl<'expr> Visitor<'expr> for UsedVisitor<'_> {
fn visit_function_id(&mut self, &func: &FunctionId) {
self.stack.push_func(func);
}
fn visit_memory_id(&mut self, &m: &MemoryId) {
self.stack.push_memory(m);
}
fn visit_global_id(&mut self, &g: &GlobalId) {
self.stack.push_global(g);
}
fn visit_table_id(&mut self, &t: &TableId) {
self.stack.push_table(t);
}
fn visit_type_id(&mut self, &t: &TypeId) {
self.stack.used.types.insert(t);
}
fn visit_data_id(&mut self, &d: &DataId) {
self.stack.push_data(d);
}
}