use crate::syntax::improper::ImproperCtype;
use crate::syntax::instantiate::ImplKey;
use crate::syntax::map::{OrderedMap, UnorderedMap};
use crate::syntax::report::Errors;
use crate::syntax::resolve::Resolution;
use crate::syntax::set::{OrderedSet, UnorderedSet};
use crate::syntax::trivial::{self, TrivialReason};
use crate::syntax::visit::{self, Visit};
use crate::syntax::{
toposort, Api, Atom, Enum, EnumRepr, ExternType, Impl, Lifetimes, Pair, Struct, Type, TypeAlias,
};
use proc_macro2::Ident;
use quote::ToTokens;
pub(crate) struct Types<'a> {
pub all: OrderedSet<&'a Type>,
pub structs: UnorderedMap<&'a Ident, &'a Struct>,
pub enums: UnorderedMap<&'a Ident, &'a Enum>,
pub cxx: UnorderedSet<&'a Ident>,
pub rust: UnorderedSet<&'a Ident>,
pub aliases: UnorderedMap<&'a Ident, &'a TypeAlias>,
pub untrusted: UnorderedMap<&'a Ident, &'a ExternType>,
pub required_trivial: UnorderedMap<&'a Ident, Vec<TrivialReason<'a>>>,
pub impls: OrderedMap<ImplKey<'a>, Option<&'a Impl>>,
pub resolutions: UnorderedMap<&'a Ident, Resolution<'a>>,
pub struct_improper_ctypes: UnorderedSet<&'a Ident>,
pub toposorted_structs: Vec<&'a Struct>,
}
impl<'a> Types<'a> {
pub(crate) fn collect(cx: &mut Errors, apis: &'a [Api]) -> Self {
let mut all = OrderedSet::new();
let mut structs = UnorderedMap::new();
let mut enums = UnorderedMap::new();
let mut cxx = UnorderedSet::new();
let mut rust = UnorderedSet::new();
let mut aliases = UnorderedMap::new();
let mut untrusted = UnorderedMap::new();
let mut impls = OrderedMap::new();
let mut resolutions = UnorderedMap::new();
let struct_improper_ctypes = UnorderedSet::new();
let toposorted_structs = Vec::new();
fn visit<'a>(all: &mut OrderedSet<&'a Type>, ty: &'a Type) {
struct CollectTypes<'s, 'a>(&'s mut OrderedSet<&'a Type>);
impl<'s, 'a> Visit<'a> for CollectTypes<'s, 'a> {
fn visit_type(&mut self, ty: &'a Type) {
self.0.insert(ty);
visit::visit_type(self, ty);
}
}
CollectTypes(all).visit_type(ty);
}
let mut add_resolution = |name: &'a Pair, generics: &'a Lifetimes| {
resolutions.insert(&name.rust, Resolution { name, generics });
};
let mut type_names = UnorderedSet::new();
let mut function_names = UnorderedSet::new();
for api in apis {
// The same identifier is permitted to be declared as both a shared
// enum and extern C++ type, or shared struct and extern C++ type.
// That indicates to not emit the C++ enum/struct definition because
// it's defined by the included headers already.
//
// All other cases of duplicate identifiers are reported as an error.
match api {
Api::Include(_) => {}
Api::Struct(strct) => {
let ident = &strct.name.rust;
if !type_names.insert(ident)
&& (!cxx.contains(ident)
|| structs.contains_key(ident)
|| enums.contains_key(ident))
{
// If already declared as a struct or enum, or if
// colliding with something other than an extern C++
// type, then error.
duplicate_name(cx, strct, ident);
}
structs.insert(&strct.name.rust, strct);
for field in &strct.fields {
visit(&mut all, &field.ty);
}
add_resolution(&strct.name, &strct.generics);
}
Api::Enum(enm) => {
match &enm.repr {
EnumRepr::Native { atom: _, repr_type } => {
all.insert(repr_type);
}
#[cfg(feature = "experimental-enum-variants-from-header")]
EnumRepr::Foreign { rust_type: _ } => {}
}
let ident = &enm.name.rust;
if !type_names.insert(ident)
&& (!cxx.contains(ident)
|| structs.contains_key(ident)
|| enums.contains_key(ident))
{
// If already declared as a struct or enum, or if
// colliding with something other than an extern C++
// type, then error.
duplicate_name(cx, enm, ident);
}
enums.insert(ident, enm);
if enm.variants_from_header {
// #![variants_from_header] enums are implicitly extern
// C++ type.
cxx.insert(&enm.name.rust);
}
add_resolution(&enm.name, &enm.generics);
}
Api::CxxType(ety) => {
let ident = &ety.name.rust;
if !type_names.insert(ident)
&& (cxx.contains(ident)
|| !structs.contains_key(ident) && !enums.contains_key(ident))
{
// If already declared as an extern C++ type, or if
// colliding with something which is neither struct nor
// enum, then error.
duplicate_name(cx, ety, ident);
}
cxx.insert(ident);
if !ety.trusted {
untrusted.insert(ident, ety);
}
add_resolution(&ety.name, &ety.generics);
}
Api::RustType(ety) => {
let ident = &ety.name.rust;
if !type_names.insert(ident) {
duplicate_name(cx, ety, ident);
}
rust.insert(ident);
add_resolution(&ety.name, &ety.generics);
}
Api::CxxFunction(efn) | Api::RustFunction(efn) => {
// Note: duplication of the C++ name is fine because C++ has
// function overloading.
if !function_names.insert((&efn.receiver, &efn.name.rust)) {
duplicate_name(cx, efn, &efn.name.rust);
}
for arg in &efn.args {
visit(&mut all, &arg.ty);
}
if let Some(ret) = &efn.ret {
visit(&mut all, ret);
}
}
Api::TypeAlias(alias) => {
let ident = &alias.name.rust;
if !type_names.insert(ident) {
duplicate_name(cx, alias, ident);
}
cxx.insert(ident);
aliases.insert(ident, alias);
add_resolution(&alias.name, &alias.generics);
}
Api::Impl(imp) => {
visit(&mut all, &imp.ty);
if let Some(key) = imp.ty.impl_key() {
impls.insert(key, Some(imp));
}
}
}
}
for ty in &all {
let Some(impl_key) = ty.impl_key() else {
continue;
};
let implicit_impl = match impl_key {
ImplKey::RustBox(ident)
| ImplKey::RustVec(ident)
| ImplKey::UniquePtr(ident)
| ImplKey::SharedPtr(ident)
| ImplKey::WeakPtr(ident)
| ImplKey::CxxVector(ident) => {
Atom::from(ident.rust).is_none() && !aliases.contains_key(ident.rust)
}
};
if implicit_impl && !impls.contains_key(&impl_key) {
impls.insert(impl_key, None);
}
}
// All these APIs may contain types passed by value. We need to ensure
// we check that this is permissible. We do this _after_ scanning all
// the APIs above, in case some function or struct references a type
// which is declared subsequently.
let required_trivial =
trivial::required_trivial_reasons(apis, &all, &structs, &enums, &cxx);
let mut types = Types {
all,
structs,
enums,
cxx,
rust,
aliases,
untrusted,
required_trivial,
impls,
resolutions,
struct_improper_ctypes,
toposorted_structs,
};
types.toposorted_structs = toposort::sort(cx, apis, &types);
let mut unresolved_structs = types.structs.keys();
let mut new_information = true;
while new_information {
new_information = false;
unresolved_structs.retain(|ident| {
let mut retain = false;
for var in &types.structs[ident].fields {
if match types.determine_improper_ctype(&var.ty) {
ImproperCtype::Depends(inner) => {
retain = true;
types.struct_improper_ctypes.contains(inner)
}
ImproperCtype::Definite(improper) => improper,
} {
types.struct_improper_ctypes.insert(ident);
new_information = true;
return false;
}
}
// If all fields definite false, remove from unresolved_structs.
retain
});
}
types
}
pub(crate) fn needs_indirect_abi(&self, ty: &Type) -> bool {
match ty {
Type::RustBox(_) | Type::UniquePtr(_) => false,
Type::Array(_) => true,
_ => !self.is_guaranteed_pod(ty),
}
}
// Types that trigger rustc's default #[warn(improper_ctypes)] lint, even if
// they may be otherwise unproblematic to mention in an extern signature.
// For example in a signature like `extern "C" fn(*const String)`, rustc
// refuses to believe that C could know how to supply us with a pointer to a
// Rust String, even though C could easily have obtained that pointer
// legitimately from a Rust call.
#[allow(dead_code)] // only used by cxxbridge-macro, not cxx-build
pub(crate) fn is_considered_improper_ctype(&self, ty: &Type) -> bool {
match self.determine_improper_ctype(ty) {
ImproperCtype::Definite(improper) => improper,
ImproperCtype::Depends(ident) => self.struct_improper_ctypes.contains(ident),
}
}
// Types which we need to assume could possibly exist by value on the Rust
// side.
pub(crate) fn is_maybe_trivial(&self, ty: &Ident) -> bool {
self.structs.contains_key(ty)
|| self.enums.contains_key(ty)
|| self.aliases.contains_key(ty)
}
}
impl<'t, 'a> IntoIterator for &'t Types<'a> {
type Item = &'a Type;
type IntoIter = crate::syntax::set::Iter<'t, 'a, Type>;
fn into_iter(self) -> Self::IntoIter {
self.all.into_iter()
}
}
fn duplicate_name(cx: &mut Errors, sp: impl ToTokens, ident: &Ident) {
let msg = format!("the name `{}` is defined multiple times", ident);
cx.error(sp, msg);
}
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