slint/internal/compiler/passes/remove_aliases.rs
Tobias Hunger 4230ac2572
Update copyright information to reflect name change
Also run resue over the codebase and fix complaints from that tool.
2022-02-09 10:27:47 +01:00

226 lines
8.4 KiB
Rust

// Copyright © SixtyFPS GmbH <info@slint-ui.com>
// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-commercial
//! This pass removes the property used in a two ways bindings
use crate::diagnostics::BuildDiagnostics;
use crate::expression_tree::{BindingExpression, NamedReference};
use crate::object_tree::*;
use std::cell::RefCell;
use std::collections::{btree_map::Entry, HashMap, HashSet};
use std::rc::Rc;
type Mapping = HashMap<NamedReference, NamedReference>;
#[derive(Default, Debug)]
struct PropertySets {
map: HashMap<NamedReference, Rc<RefCell<HashSet<NamedReference>>>>,
all_sets: Vec<Rc<RefCell<HashSet<NamedReference>>>>,
}
impl PropertySets {
fn add_link(&mut self, p1: NamedReference, p2: NamedReference) {
if !std::rc::Weak::ptr_eq(
&p1.element().borrow().enclosing_component,
&p2.element().borrow().enclosing_component,
) && (p1.element().borrow().enclosing_component.upgrade().unwrap().is_global()
== p2.element().borrow().enclosing_component.upgrade().unwrap().is_global())
{
// We can only merge aliases if they are in the same Component. (unless one of them is global)
// TODO: actually we could still merge two alias in a component pointing to the same
// property in a parent component
return;
}
if let Some(s1) = self.map.get(&p1).cloned() {
if let Some(s2) = self.map.get(&p2).cloned() {
if Rc::ptr_eq(&s1, &s2) {
return;
}
for x in s1.borrow().iter() {
self.map.insert(x.clone(), s2.clone());
s2.borrow_mut().insert(x.clone());
}
*s1.borrow_mut() = HashSet::new();
} else {
s1.borrow_mut().insert(p2.clone());
self.map.insert(p2, s1);
}
} else if let Some(s2) = self.map.get(&p2).cloned() {
s2.borrow_mut().insert(p1.clone());
self.map.insert(p1, s2);
} else {
let mut set = HashSet::new();
set.insert(p1.clone());
set.insert(p2.clone());
let set = Rc::new(RefCell::new(set));
self.map.insert(p1, set.clone());
self.map.insert(p2, set.clone());
self.all_sets.push(set)
}
}
}
pub fn remove_aliases(component: &Rc<Component>, diag: &mut BuildDiagnostics) {
// collect all sets that are linked together
let mut property_sets = PropertySets::default();
let mut process_element = |e: &ElementRc| {
'bindings: for (name, binding) in &e.borrow().bindings {
for nr in &binding.borrow().two_way_bindings {
let other_e = nr.element();
if name == nr.name() && Rc::ptr_eq(e, &other_e) {
diag.push_error("Property cannot alias to itself".into(), &*binding.borrow());
continue 'bindings;
}
property_sets.add_link(NamedReference::new(e, name), nr.clone());
}
}
};
recurse_elem_including_sub_components(component, &(), &mut |e, &()| process_element(e));
for g in &component.used_types.borrow().globals {
process_element(&g.root_element)
}
// The key will be removed and replaced by the named reference
let mut aliases_to_remove = Mapping::new();
// For each set, find a "master" property. Only reference to this master property will be kept,
// and only the master property will keep its binding
for set in property_sets.all_sets {
let set = set.borrow();
let mut set_iter = set.iter();
if let Some(mut best) = set_iter.next().cloned() {
for candidate in set_iter {
best = best_property(component, best.clone(), candidate.clone());
}
for x in set.iter() {
if *x != best {
aliases_to_remove.insert(x.clone(), best.clone());
}
}
}
}
// Do the replacements
visit_all_named_references(component, &mut |nr: &mut NamedReference| {
if let Some(new) = aliases_to_remove.get(nr) {
*nr = new.clone();
}
});
// Remove the properties
for (remove, to) in aliases_to_remove {
let elem = remove.element();
// adjust the bindings
let old_binding = elem.borrow_mut().bindings.remove(remove.name());
let must_simplify = if let Some(mut binding) = old_binding.map(RefCell::into_inner) {
remove_from_binding_expression(&mut binding, &to);
if binding.has_binding() {
let to_elem = to.element();
match to_elem.borrow_mut().bindings.entry(to.name().to_owned()) {
Entry::Occupied(mut e) => {
let b = e.get_mut().get_mut();
remove_from_binding_expression(b, &to);
if b.priority < binding.priority || !b.has_binding() {
b.merge_with(&binding);
} else {
binding.merge_with(b);
*b = binding;
}
}
Entry::Vacant(e) => {
e.insert(binding.into());
}
};
false
} else {
true
}
} else {
true
};
if must_simplify {
let to_elem = to.element();
let mut to_elem = to_elem.borrow_mut();
if let Some(b) = to_elem.bindings.get_mut(to.name()) {
remove_from_binding_expression(b.get_mut(), &to);
if !b.get_mut().has_binding() {
to_elem.bindings.remove(to.name());
}
}
}
// Remove the declaration
{
let mut elem = elem.borrow_mut();
let used_externally = elem
.property_analysis
.borrow()
.get(remove.name())
.map_or(false, |v| v.is_read_externally || v.is_set_externally);
if let Some(d) = elem.property_declarations.get_mut(remove.name()) {
if d.expose_in_public_api || used_externally {
d.is_alias = Some(to.clone());
drop(elem);
// one must mark the aliased property as settable from outside
to.mark_as_set();
} else {
elem.property_declarations.remove(remove.name());
let analysis = elem.property_analysis.borrow().get(remove.name()).cloned();
if let Some(analysis) = analysis {
drop(elem);
to.element()
.borrow()
.property_analysis
.borrow_mut()
.entry(to.name().to_owned())
.or_default()
.merge(&analysis);
};
}
} else {
// This is not a declaration, we must re-create the binding
elem.bindings
.insert(remove.name().to_owned(), BindingExpression::new_two_way(to).into());
}
}
}
}
fn is_declaration(x: &NamedReference) -> bool {
x.element().borrow().property_declarations.contains_key(x.name())
}
/// Out of two named reference, return the one which is the best to keep.
fn best_property(
component: &Rc<Component>,
p1: NamedReference,
p2: NamedReference,
) -> NamedReference {
// Try to find which is the more canonical property
macro_rules! canonical_order {
($x: expr) => {{
(
!$x.element().borrow().enclosing_component.upgrade().unwrap().is_global(),
is_declaration(&$x),
!Rc::ptr_eq(&component.root_element, &$x.element()),
$x.element().borrow().id.clone(),
$x.name(),
)
}};
}
if canonical_order!(p1) < canonical_order!(p2) {
p1
} else {
p2
}
}
/// Remove the `to` from the two_way_bindings
fn remove_from_binding_expression(expression: &mut BindingExpression, to: &NamedReference) {
expression.two_way_bindings.retain(|x| x != to);
}