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fuchsia / third_party / github.com / rust-lang / rust-bindgen / 0f641061a78b8af93e977e072cfd8106461b3ca5 / . / src / codegen / mod.rs
blob: b823fb340c1b408e75a5d017662b67900b6fdf13 [file] [log] [blame]
mod dyngen;
mod error;
mod helpers;
mod impl_debug;
mod impl_partialeq;
pub mod struct_layout;
#[cfg(test)]
#[allow(warnings)]
pub(crate) mod bitfield_unit;
#[cfg(all(test, target_endian = "little"))]
mod bitfield_unit_tests;
use self::dyngen::DynamicItems;
use self::helpers::attributes;
use self::struct_layout::StructLayoutTracker;
use super::BindgenOptions;
use crate::ir::analysis::{HasVtable, Sizedness};
use crate::ir::annotations::FieldAccessorKind;
use crate::ir::comment;
use crate::ir::comp::{
Base, Bitfield, BitfieldUnit, CompInfo, CompKind, Field, FieldData,
FieldMethods, Method, MethodKind,
};
use crate::ir::context::{BindgenContext, ItemId};
use crate::ir::derive::{
CanDerive, CanDeriveCopy, CanDeriveDebug, CanDeriveDefault, CanDeriveEq,
CanDeriveHash, CanDeriveOrd, CanDerivePartialEq, CanDerivePartialOrd,
};
use crate::ir::dot;
use crate::ir::enum_ty::{Enum, EnumVariant, EnumVariantValue};
use crate::ir::function::{Abi, Function, FunctionKind, FunctionSig, Linkage};
use crate::ir::int::IntKind;
use crate::ir::item::{IsOpaque, Item, ItemCanonicalName, ItemCanonicalPath};
use crate::ir::item_kind::ItemKind;
use crate::ir::layout::Layout;
use crate::ir::module::Module;
use crate::ir::objc::{ObjCInterface, ObjCMethod};
use crate::ir::template::{
AsTemplateParam, TemplateInstantiation, TemplateParameters,
};
use crate::ir::ty::{Type, TypeKind};
use crate::ir::var::Var;
use proc_macro2::{self, Ident, Span};
use quote::TokenStreamExt;
use crate::{Entry, HashMap, HashSet};
use std;
use std::borrow::Cow;
use std::cell::Cell;
use std::collections::VecDeque;
use std::fmt::Write;
use std::iter;
use std::ops;
use std::str::FromStr;
// Name of type defined in constified enum module
pub static CONSTIFIED_ENUM_MODULE_REPR_NAME: &'static str = "Type";
fn top_level_path(
ctx: &BindgenContext,
item: &Item,
) -> Vec<proc_macro2::TokenStream> {
let mut path = vec![quote! { self }];
if ctx.options().enable_cxx_namespaces {
for _ in 0..item.codegen_depth(ctx) {
path.push(quote! { super });
}
}
path
}
fn root_import(
ctx: &BindgenContext,
module: &Item,
) -> proc_macro2::TokenStream {
assert!(ctx.options().enable_cxx_namespaces, "Somebody messed it up");
assert!(module.is_module());
let mut path = top_level_path(ctx, module);
let root = ctx.root_module().canonical_name(ctx);
let root_ident = ctx.rust_ident(&root);
path.push(quote! { #root_ident });
let mut tokens = quote! {};
tokens.append_separated(path, quote!(::));
quote! {
#[allow(unused_imports)]
use #tokens ;
}
}
bitflags! {
struct DerivableTraits: u16 {
const DEBUG = 1 << 0;
const DEFAULT = 1 << 1;
const COPY = 1 << 2;
const CLONE = 1 << 3;
const HASH = 1 << 4;
const PARTIAL_ORD = 1 << 5;
const ORD = 1 << 6;
const PARTIAL_EQ = 1 << 7;
const EQ = 1 << 8;
}
}
fn derives_of_item(item: &Item, ctx: &BindgenContext) -> DerivableTraits {
let mut derivable_traits = DerivableTraits::empty();
if item.can_derive_debug(ctx) && !item.annotations().disallow_debug() {
derivable_traits |= DerivableTraits::DEBUG;
}
if item.can_derive_default(ctx) && !item.annotations().disallow_default() {
derivable_traits |= DerivableTraits::DEFAULT;
}
let all_template_params = item.all_template_params(ctx);
if item.can_derive_copy(ctx) && !item.annotations().disallow_copy() {
derivable_traits |= DerivableTraits::COPY;
if ctx.options().rust_features().builtin_clone_impls ||
!all_template_params.is_empty()
{
// FIXME: This requires extra logic if you have a big array in a
// templated struct. The reason for this is that the magic:
// fn clone(&self) -> Self { *self }
// doesn't work for templates.
//
// It's not hard to fix though.
derivable_traits |= DerivableTraits::CLONE;
}
}
if item.can_derive_hash(ctx) {
derivable_traits |= DerivableTraits::HASH;
}
if item.can_derive_partialord(ctx) {
derivable_traits |= DerivableTraits::PARTIAL_ORD;
}
if item.can_derive_ord(ctx) {
derivable_traits |= DerivableTraits::ORD;
}
if item.can_derive_partialeq(ctx) {
derivable_traits |= DerivableTraits::PARTIAL_EQ;
}
if item.can_derive_eq(ctx) {
derivable_traits |= DerivableTraits::EQ;
}
derivable_traits
}
impl From<DerivableTraits> for Vec<&'static str> {
fn from(derivable_traits: DerivableTraits) -> Vec<&'static str> {
[
(DerivableTraits::DEBUG, "Debug"),
(DerivableTraits::DEFAULT, "Default"),
(DerivableTraits::COPY, "Copy"),
(DerivableTraits::CLONE, "Clone"),
(DerivableTraits::HASH, "Hash"),
(DerivableTraits::PARTIAL_ORD, "PartialOrd"),
(DerivableTraits::ORD, "Ord"),
(DerivableTraits::PARTIAL_EQ, "PartialEq"),
(DerivableTraits::EQ, "Eq"),
]
.iter()
.filter_map(|&(flag, derive)| {
Some(derive).filter(|_| derivable_traits.contains(flag))
})
.collect()
}
}
struct CodegenResult<'a> {
items: Vec<proc_macro2::TokenStream>,
dynamic_items: DynamicItems,
/// A monotonic counter used to add stable unique id's to stuff that doesn't
/// need to be referenced by anything.
codegen_id: &'a Cell<usize>,
/// Whether a bindgen union has been generated at least once.
saw_bindgen_union: bool,
/// Whether an incomplete array has been generated at least once.
saw_incomplete_array: bool,
/// Whether Objective C types have been seen at least once.
saw_objc: bool,
/// Whether Apple block types have been seen at least once.
saw_block: bool,
/// Whether a bitfield allocation unit has been seen at least once.
saw_bitfield_unit: bool,
items_seen: HashSet<ItemId>,
/// The set of generated function/var names, needed because in C/C++ is
/// legal to do something like:
///
/// ```c++
/// extern "C" {
/// void foo();
/// extern int bar;
/// }
///
/// extern "C" {
/// void foo();
/// extern int bar;
/// }
/// ```
///
/// Being these two different declarations.
functions_seen: HashSet<String>,
vars_seen: HashSet<String>,
/// Used for making bindings to overloaded functions. Maps from a canonical
/// function name to the number of overloads we have already codegen'd for
/// that name. This lets us give each overload a unique suffix.
overload_counters: HashMap<String, u32>,
}
impl<'a> CodegenResult<'a> {
fn new(codegen_id: &'a Cell<usize>) -> Self {
CodegenResult {
items: vec![],
dynamic_items: DynamicItems::new(),
saw_bindgen_union: false,
saw_incomplete_array: false,
saw_objc: false,
saw_block: false,
saw_bitfield_unit: false,
codegen_id,
items_seen: Default::default(),
functions_seen: Default::default(),
vars_seen: Default::default(),
overload_counters: Default::default(),
}
}
fn dynamic_items(&mut self) -> &mut DynamicItems {
&mut self.dynamic_items
}
fn saw_bindgen_union(&mut self) {
self.saw_bindgen_union = true;
}
fn saw_incomplete_array(&mut self) {
self.saw_incomplete_array = true;
}
fn saw_objc(&mut self) {
self.saw_objc = true;
}
fn saw_block(&mut self) {
self.saw_block = true;
}
fn saw_bitfield_unit(&mut self) {
self.saw_bitfield_unit = true;
}
fn seen<Id: Into<ItemId>>(&self, item: Id) -> bool {
self.items_seen.contains(&item.into())
}
fn set_seen<Id: Into<ItemId>>(&mut self, item: Id) {
self.items_seen.insert(item.into());
}
fn seen_function(&self, name: &str) -> bool {
self.functions_seen.contains(name)
}
fn saw_function(&mut self, name: &str) {
self.functions_seen.insert(name.into());
}
/// Get the overload number for the given function name. Increments the
/// counter internally so the next time we ask for the overload for this
/// name, we get the incremented value, and so on.
fn overload_number(&mut self, name: &str) -> u32 {
let counter = self.overload_counters.entry(name.into()).or_insert(0);
let number = *counter;
*counter += 1;
number
}
fn seen_var(&self, name: &str) -> bool {
self.vars_seen.contains(name)
}
fn saw_var(&mut self, name: &str) {
self.vars_seen.insert(name.into());
}
fn inner<F>(&mut self, cb: F) -> Vec<proc_macro2::TokenStream>
where
F: FnOnce(&mut Self),
{
let mut new = Self::new(self.codegen_id);
cb(&mut new);
self.saw_incomplete_array |= new.saw_incomplete_array;
self.saw_objc |= new.saw_objc;
self.saw_block |= new.saw_block;
self.saw_bitfield_unit |= new.saw_bitfield_unit;
self.saw_bindgen_union |= new.saw_bindgen_union;
new.items
}
}
impl<'a> ops::Deref for CodegenResult<'a> {
type Target = Vec<proc_macro2::TokenStream>;
fn deref(&self) -> &Self::Target {
&self.items
}
}
impl<'a> ops::DerefMut for CodegenResult<'a> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.items
}
}
/// A trait to convert a rust type into a pointer, optionally const, to the same
/// type.
trait ToPtr {
fn to_ptr(self, is_const: bool) -> proc_macro2::TokenStream;
}
impl ToPtr for proc_macro2::TokenStream {
fn to_ptr(self, is_const: bool) -> proc_macro2::TokenStream {
if is_const {
quote! { *const #self }
} else {
quote! { *mut #self }
}
}
}
/// An extension trait for `proc_macro2::TokenStream` that lets us append any implicit
/// template parameters that exist for some type, if necessary.
trait AppendImplicitTemplateParams {
fn append_implicit_template_params(
&mut self,
ctx: &BindgenContext,
item: &Item,
);
}
impl AppendImplicitTemplateParams for proc_macro2::TokenStream {
fn append_implicit_template_params(
&mut self,
ctx: &BindgenContext,
item: &Item,
) {
let item = item.id().into_resolver().through_type_refs().resolve(ctx);
match *item.expect_type().kind() {
TypeKind::UnresolvedTypeRef(..) => {
unreachable!("already resolved unresolved type refs")
}
TypeKind::ResolvedTypeRef(..) => {
unreachable!("we resolved item through type refs")
}
// None of these types ever have implicit template parameters.
TypeKind::Void |
TypeKind::NullPtr |
TypeKind::Pointer(..) |
TypeKind::Reference(..) |
TypeKind::Int(..) |
TypeKind::Float(..) |
TypeKind::Complex(..) |
TypeKind::Array(..) |
TypeKind::TypeParam |
TypeKind::Opaque |
TypeKind::Function(..) |
TypeKind::Enum(..) |
TypeKind::ObjCId |
TypeKind::ObjCSel |
TypeKind::TemplateInstantiation(..) => return,
_ => {}
}
let params: Vec<_> = item
.used_template_params(ctx)
.iter()
.map(|p| {
p.try_to_rust_ty(ctx, &())
.expect("template params cannot fail to be a rust type")
})
.collect();
if !params.is_empty() {
self.append_all(quote! {
< #( #params ),* >
});
}
}
}
trait CodeGenerator {
/// Extra information from the caller.
type Extra;
/// Extra information returned to the caller.
type Return;
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
extra: &Self::Extra,
) -> Self::Return;
}
impl Item {
fn process_before_codegen(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult,
) -> bool {
if !self.is_enabled_for_codegen(ctx) {
return false;
}
if self.is_blocklisted(ctx) || result.seen(self.id()) {
debug!(
"<Item as CodeGenerator>::process_before_codegen: Ignoring hidden or seen: \
self = {:?}",
self
);
return false;
}
if !ctx.codegen_items().contains(&self.id()) {
// TODO(emilio, #453): Figure out what to do when this happens
// legitimately, we could track the opaque stuff and disable the
// assertion there I guess.
warn!("Found non-allowlisted item in code generation: {:?}", self);
}
result.set_seen(self.id());
true
}
}
impl CodeGenerator for Item {
type Extra = ();
type Return = ();
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
_extra: &(),
) {
debug!("<Item as CodeGenerator>::codegen: self = {:?}", self);
if !self.process_before_codegen(ctx, result) {
return;
}
match *self.kind() {
ItemKind::Module(ref module) => {
module.codegen(ctx, result, self);
}
ItemKind::Function(ref fun) => {
fun.codegen(ctx, result, self);
}
ItemKind::Var(ref var) => {
var.codegen(ctx, result, self);
}
ItemKind::Type(ref ty) => {
ty.codegen(ctx, result, self);
}
}
}
}
impl CodeGenerator for Module {
type Extra = Item;
type Return = ();
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
item: &Item,
) {
debug!("<Module as CodeGenerator>::codegen: item = {:?}", item);
let codegen_self = |result: &mut CodegenResult,
found_any: &mut bool| {
for child in self.children() {
if ctx.codegen_items().contains(child) {
*found_any = true;
ctx.resolve_item(*child).codegen(ctx, result, &());
}
}
if item.id() == ctx.root_module() {
if result.saw_block {
utils::prepend_block_header(ctx, &mut *result);
}
if result.saw_bindgen_union {
utils::prepend_union_types(ctx, &mut *result);
}
if result.saw_incomplete_array {
utils::prepend_incomplete_array_types(ctx, &mut *result);
}
if ctx.need_bindgen_complex_type() {
utils::prepend_complex_type(&mut *result);
}
if result.saw_objc {
utils::prepend_objc_header(ctx, &mut *result);
}
if result.saw_bitfield_unit {
utils::prepend_bitfield_unit_type(ctx, &mut *result);
}
}
};
if !ctx.options().enable_cxx_namespaces ||
(self.is_inline() &&
!ctx.options().conservative_inline_namespaces)
{
codegen_self(result, &mut false);
return;
}
let mut found_any = false;
let inner_items = result.inner(|result| {
result.push(root_import(ctx, item));
let path = item.namespace_aware_canonical_path(ctx).join("::");
if let Some(raw_lines) = ctx.options().module_lines.get(&path) {
for raw_line in raw_lines {
found_any = true;
result.push(
proc_macro2::TokenStream::from_str(raw_line).unwrap(),
);
}
}
codegen_self(result, &mut found_any);
});
// Don't bother creating an empty module.
if !found_any {
return;
}
let name = item.canonical_name(ctx);
let ident = ctx.rust_ident(name);
result.push(if item.id() == ctx.root_module() {
quote! {
#[allow(non_snake_case, non_camel_case_types, non_upper_case_globals)]
pub mod #ident {
#( #inner_items )*
}
}
} else {
quote! {
pub mod #ident {
#( #inner_items )*
}
}
});
}
}
impl CodeGenerator for Var {
type Extra = Item;
type Return = ();
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
item: &Item,
) {
use crate::ir::var::VarType;
debug!("<Var as CodeGenerator>::codegen: item = {:?}", item);
debug_assert!(item.is_enabled_for_codegen(ctx));
let canonical_name = item.canonical_name(ctx);
if result.seen_var(&canonical_name) {
return;
}
result.saw_var(&canonical_name);
let canonical_ident = ctx.rust_ident(&canonical_name);
// We can't generate bindings to static variables of templates. The
// number of actual variables for a single declaration are open ended
// and we don't know what instantiations do or don't exist.
if !item.all_template_params(ctx).is_empty() {
return;
}
let mut attrs = vec![];
if let Some(comment) = item.comment(ctx) {
attrs.push(attributes::doc(comment));
}
let ty = self.ty().to_rust_ty_or_opaque(ctx, &());
if let Some(val) = self.val() {
match *val {
VarType::Bool(val) => {
result.push(quote! {
#(#attrs)*
pub const #canonical_ident : #ty = #val ;
});
}
VarType::Int(val) => {
let int_kind = self
.ty()
.into_resolver()
.through_type_aliases()
.through_type_refs()
.resolve(ctx)
.expect_type()
.as_integer()
.unwrap();
let val = if int_kind.is_signed() {
helpers::ast_ty::int_expr(val)
} else {
helpers::ast_ty::uint_expr(val as _)
};
result.push(quote! {
#(#attrs)*
pub const #canonical_ident : #ty = #val ;
});
}
VarType::String(ref bytes) => {
// Account the trailing zero.
//
// TODO: Here we ignore the type we just made up, probably
// we should refactor how the variable type and ty id work.
let len = bytes.len() + 1;
let ty = quote! {
[u8; #len]
};
match String::from_utf8(bytes.clone()) {
Ok(string) => {
let cstr = helpers::ast_ty::cstr_expr(string);
result.push(quote! {
#(#attrs)*
pub const #canonical_ident : &'static #ty = #cstr ;
});
}
Err(..) => {
let bytes = helpers::ast_ty::byte_array_expr(bytes);
result.push(quote! {
#(#attrs)*
pub const #canonical_ident : #ty = #bytes ;
});
}
}
}
VarType::Float(f) => {
match helpers::ast_ty::float_expr(ctx, f) {
Ok(expr) => result.push(quote! {
#(#attrs)*
pub const #canonical_ident : #ty = #expr ;
}),
Err(..) => return,
}
}
VarType::Char(c) => {
result.push(quote! {
#(#attrs)*
pub const #canonical_ident : #ty = #c ;
});
}
}
} else {
// If necessary, apply a `#[link_name]` attribute
let link_name = self.mangled_name().unwrap_or(self.name());
if !utils::names_will_be_identical_after_mangling(
&canonical_name,
link_name,
None,
) {
attrs.push(attributes::link_name(link_name));
}
let maybe_mut = if self.is_const() {
quote! {}
} else {
quote! { mut }
};
let tokens = quote!(
extern "C" {
#(#attrs)*
pub static #maybe_mut #canonical_ident: #ty;
}
);
result.push(tokens);
}
}
}
impl CodeGenerator for Type {
type Extra = Item;
type Return = ();
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
item: &Item,
) {
debug!("<Type as CodeGenerator>::codegen: item = {:?}", item);
debug_assert!(item.is_enabled_for_codegen(ctx));
match *self.kind() {
TypeKind::Void |
TypeKind::NullPtr |
TypeKind::Int(..) |
TypeKind::Float(..) |
TypeKind::Complex(..) |
TypeKind::Array(..) |
TypeKind::Vector(..) |
TypeKind::Pointer(..) |
TypeKind::Reference(..) |
TypeKind::Function(..) |
TypeKind::ResolvedTypeRef(..) |
TypeKind::Opaque |
TypeKind::TypeParam => {
// These items don't need code generation, they only need to be
// converted to rust types in fields, arguments, and such.
// NOTE(emilio): If you add to this list, make sure to also add
// it to BindgenContext::compute_allowlisted_and_codegen_items.
return;
}
TypeKind::TemplateInstantiation(ref inst) => {
inst.codegen(ctx, result, item)
}
TypeKind::BlockPointer(inner) => {
if !ctx.options().generate_block {
return;
}
let inner_item =
inner.into_resolver().through_type_refs().resolve(ctx);
let name = item.canonical_name(ctx);
let inner_rust_type = {
if let TypeKind::Function(fnsig) =
inner_item.kind().expect_type().kind()
{
utils::fnsig_block(ctx, fnsig)
} else {
panic!("invalid block typedef: {:?}", inner_item)
}
};
let rust_name = ctx.rust_ident(&name);
let mut tokens = if let Some(comment) = item.comment(ctx) {
attributes::doc(comment)
} else {
quote! {}
};
tokens.append_all(quote! {
pub type #rust_name = #inner_rust_type ;
});
result.push(tokens);
result.saw_block();
}
TypeKind::Comp(ref ci) => ci.codegen(ctx, result, item),
TypeKind::TemplateAlias(inner, _) | TypeKind::Alias(inner) => {
let inner_item =
inner.into_resolver().through_type_refs().resolve(ctx);
let name = item.canonical_name(ctx);
let path = item.canonical_path(ctx);
{
let through_type_aliases = inner
.into_resolver()
.through_type_refs()
.through_type_aliases()
.resolve(ctx);
// Try to catch the common pattern:
//
// typedef struct foo { ... } foo;
//
// here, and also other more complex cases like #946.
if through_type_aliases.canonical_path(ctx) == path {
return;
}
}
// If this is a known named type, disallow generating anything
// for it too.
let spelling = self.name().expect("Unnamed alias?");
if utils::type_from_named(ctx, spelling).is_some() {
return;
}
let mut outer_params = item.used_template_params(ctx);
let is_opaque = item.is_opaque(ctx, &());
let inner_rust_type = if is_opaque {
outer_params = vec![];
self.to_opaque(ctx, item)
} else {
// Its possible that we have better layout information than
// the inner type does, so fall back to an opaque blob based
// on our layout if converting the inner item fails.
let mut inner_ty = inner_item
.try_to_rust_ty_or_opaque(ctx, &())
.unwrap_or_else(|_| self.to_opaque(ctx, item));
inner_ty.append_implicit_template_params(ctx, inner_item);
inner_ty
};
{
// FIXME(emilio): This is a workaround to avoid generating
// incorrect type aliases because of types that we haven't
// been able to resolve (because, eg, they depend on a
// template parameter).
//
// It's kind of a shame not generating them even when they
// could be referenced, but we already do the same for items
// with invalid template parameters, and at least this way
// they can be replaced, instead of generating plain invalid
// code.
let inner_canon_type =
inner_item.expect_type().canonical_type(ctx);
if inner_canon_type.is_invalid_type_param() {
warn!(
"Item contained invalid named type, skipping: \
{:?}, {:?}",
item, inner_item
);
return;
}
}
let rust_name = ctx.rust_ident(&name);
let mut tokens = if let Some(comment) = item.comment(ctx) {
attributes::doc(comment)
} else {
quote! {}
};
let alias_style = if ctx.options().type_alias.matches(&name) {
AliasVariation::TypeAlias
} else if ctx.options().new_type_alias.matches(&name) {
AliasVariation::NewType
} else if ctx.options().new_type_alias_deref.matches(&name) {
AliasVariation::NewTypeDeref
} else {
ctx.options().default_alias_style
};
// We prefer using `pub use` over `pub type` because of:
// https://github.com/rust-lang/rust/issues/26264
if inner_rust_type.to_string().chars().all(|c| match c {
// These are the only characters allowed in simple
// paths, eg `good::dogs::Bront`.
'A'..='Z' | 'a'..='z' | '0'..='9' | ':' | '_' | ' ' => true,
_ => false,
}) && outer_params.is_empty() &&
!is_opaque &&
alias_style == AliasVariation::TypeAlias &&
inner_item.expect_type().canonical_type(ctx).is_enum()
{
tokens.append_all(quote! {
pub use
});
let path = top_level_path(ctx, item);
tokens.append_separated(path, quote!(::));
tokens.append_all(quote! {
:: #inner_rust_type as #rust_name ;
});
result.push(tokens);
return;
}
tokens.append_all(match alias_style {
AliasVariation::TypeAlias => quote! {
pub type #rust_name
},
AliasVariation::NewType | AliasVariation::NewTypeDeref => {
assert!(
ctx.options().rust_features().repr_transparent,
"repr_transparent feature is required to use {:?}",
alias_style
);
let mut attributes =
vec![attributes::repr("transparent")];
let derivable_traits = derives_of_item(item, ctx);
if !derivable_traits.is_empty() {
let derives: Vec<_> = derivable_traits.into();
attributes.push(attributes::derives(&derives))
}
quote! {
#( #attributes )*
pub struct #rust_name
}
}
});
let params: Vec<_> = outer_params
.into_iter()
.filter_map(|p| p.as_template_param(ctx, &()))
.collect();
if params
.iter()
.any(|p| ctx.resolve_type(*p).is_invalid_type_param())
{
warn!(
"Item contained invalid template \
parameter: {:?}",
item
);
return;
}
let params: Vec<_> = params
.iter()
.map(|p| {
p.try_to_rust_ty(ctx, &()).expect(
"type parameters can always convert to rust ty OK",
)
})
.collect();
if !params.is_empty() {
tokens.append_all(quote! {
< #( #params ),* >
});
}
tokens.append_all(match alias_style {
AliasVariation::TypeAlias => quote! {
= #inner_rust_type ;
},
AliasVariation::NewType | AliasVariation::NewTypeDeref => {
quote! {
(pub #inner_rust_type) ;
}
}
});
if alias_style == AliasVariation::NewTypeDeref {
let prefix = ctx.trait_prefix();
tokens.append_all(quote! {
impl ::#prefix::ops::Deref for #rust_name {
type Target = #inner_rust_type;
#[inline]
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl ::#prefix::ops::DerefMut for #rust_name {
#[inline]
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
});
}
result.push(tokens);
}
TypeKind::Enum(ref ei) => ei.codegen(ctx, result, item),
TypeKind::ObjCId | TypeKind::ObjCSel => {
result.saw_objc();
}
TypeKind::ObjCInterface(ref interface) => {
interface.codegen(ctx, result, item)
}
ref u @ TypeKind::UnresolvedTypeRef(..) => {
unreachable!("Should have been resolved after parsing {:?}!", u)
}
}
}
}
struct Vtable<'a> {
item_id: ItemId,
#[allow(dead_code)]
methods: &'a [Method],
#[allow(dead_code)]
base_classes: &'a [Base],
}
impl<'a> Vtable<'a> {
fn new(
item_id: ItemId,
methods: &'a [Method],
base_classes: &'a [Base],
) -> Self {
Vtable {
item_id,
methods,
base_classes,
}
}
}
impl<'a> CodeGenerator for Vtable<'a> {
type Extra = Item;
type Return = ();
fn codegen<'b>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'b>,
item: &Item,
) {
assert_eq!(item.id(), self.item_id);
debug_assert!(item.is_enabled_for_codegen(ctx));
// For now, generate an empty struct, later we should generate function
// pointers and whatnot.
let name = ctx.rust_ident(&self.canonical_name(ctx));
let void = helpers::ast_ty::c_void(ctx);
result.push(quote! {
#[repr(C)]
pub struct #name ( #void );
});
}
}
impl<'a> ItemCanonicalName for Vtable<'a> {
fn canonical_name(&self, ctx: &BindgenContext) -> String {
format!("{}__bindgen_vtable", self.item_id.canonical_name(ctx))
}
}
impl<'a> TryToRustTy for Vtable<'a> {
type Extra = ();
fn try_to_rust_ty(
&self,
ctx: &BindgenContext,
_: &(),
) -> error::Result<proc_macro2::TokenStream> {
let name = ctx.rust_ident(self.canonical_name(ctx));
Ok(quote! {
#name
})
}
}
impl CodeGenerator for TemplateInstantiation {
type Extra = Item;
type Return = ();
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
item: &Item,
) {
debug_assert!(item.is_enabled_for_codegen(ctx));
// Although uses of instantiations don't need code generation, and are
// just converted to rust types in fields, vars, etc, we take this
// opportunity to generate tests for their layout here. If the
// instantiation is opaque, then its presumably because we don't
// properly understand it (maybe because of specializations), and so we
// shouldn't emit layout tests either.
if !ctx.options().layout_tests || self.is_opaque(ctx, item) {
return;
}
// If there are any unbound type parameters, then we can't generate a
// layout test because we aren't dealing with a concrete type with a
// concrete size and alignment.
if ctx.uses_any_template_parameters(item.id()) {
return;
}
let layout = item.kind().expect_type().layout(ctx);
if let Some(layout) = layout {
let size = layout.size;
let align = layout.align;
let name = item.full_disambiguated_name(ctx);
let mut fn_name =
format!("__bindgen_test_layout_{}_instantiation", name);
let times_seen = result.overload_number(&fn_name);
if times_seen > 0 {
write!(&mut fn_name, "_{}", times_seen).unwrap();
}
let fn_name = ctx.rust_ident_raw(fn_name);
let prefix = ctx.trait_prefix();
let ident = item.to_rust_ty_or_opaque(ctx, &());
let size_of_expr = quote! {
::#prefix::mem::size_of::<#ident>()
};
let align_of_expr = quote! {
::#prefix::mem::align_of::<#ident>()
};
let item = quote! {
#[test]
fn #fn_name() {
assert_eq!(#size_of_expr, #size,
concat!("Size of template specialization: ",
stringify!(#ident)));
assert_eq!(#align_of_expr, #align,
concat!("Alignment of template specialization: ",
stringify!(#ident)));
}
};
result.push(item);
}
}
}
/// Trait for implementing the code generation of a struct or union field.
trait FieldCodegen<'a> {
type Extra;
fn codegen<F, M>(
&self,
ctx: &BindgenContext,
fields_should_be_private: bool,
codegen_depth: usize,
accessor_kind: FieldAccessorKind,
parent: &CompInfo,
result: &mut CodegenResult,
struct_layout: &mut StructLayoutTracker,
fields: &mut F,
methods: &mut M,
extra: Self::Extra,
) where
F: Extend<proc_macro2::TokenStream>,
M: Extend<proc_macro2::TokenStream>;
}
impl<'a> FieldCodegen<'a> for Field {
type Extra = ();
fn codegen<F, M>(
&self,
ctx: &BindgenContext,
fields_should_be_private: bool,
codegen_depth: usize,
accessor_kind: FieldAccessorKind,
parent: &CompInfo,
result: &mut CodegenResult,
struct_layout: &mut StructLayoutTracker,
fields: &mut F,
methods: &mut M,
_: (),
) where
F: Extend<proc_macro2::TokenStream>,
M: Extend<proc_macro2::TokenStream>,
{
match *self {
Field::DataMember(ref data) => {
data.codegen(
ctx,
fields_should_be_private,
codegen_depth,
accessor_kind,
parent,
result,
struct_layout,
fields,
methods,
(),
);
}
Field::Bitfields(ref unit) => {
unit.codegen(
ctx,
fields_should_be_private,
codegen_depth,
accessor_kind,
parent,
result,
struct_layout,
fields,
methods,
(),
);
}
}
}
}
impl<'a> FieldCodegen<'a> for FieldData {
type Extra = ();
fn codegen<F, M>(
&self,
ctx: &BindgenContext,
fields_should_be_private: bool,
codegen_depth: usize,
accessor_kind: FieldAccessorKind,
parent: &CompInfo,
result: &mut CodegenResult,
struct_layout: &mut StructLayoutTracker,
fields: &mut F,
methods: &mut M,
_: (),
) where
F: Extend<proc_macro2::TokenStream>,
M: Extend<proc_macro2::TokenStream>,
{
// Bitfields are handled by `FieldCodegen` implementations for
// `BitfieldUnit` and `Bitfield`.
assert!(self.bitfield_width().is_none());
let field_item =
self.ty().into_resolver().through_type_refs().resolve(ctx);
let field_ty = field_item.expect_type();
let mut ty = self.ty().to_rust_ty_or_opaque(ctx, &());
ty.append_implicit_template_params(ctx, field_item);
// NB: If supported, we use proper `union` types.
let ty = if parent.is_union() && !struct_layout.is_rust_union() {
result.saw_bindgen_union();
if ctx.options().enable_cxx_namespaces {
quote! {
root::__BindgenUnionField<#ty>
}
} else {
quote! {
__BindgenUnionField<#ty>
}
}
} else if let Some(item) = field_ty.is_incomplete_array(ctx) {
result.saw_incomplete_array();
let inner = item.to_rust_ty_or_opaque(ctx, &());
if ctx.options().enable_cxx_namespaces {
quote! {
root::__IncompleteArrayField<#inner>
}
} else {
quote! {
__IncompleteArrayField<#inner>
}
}
} else {
ty
};
let mut field = quote! {};
if ctx.options().generate_comments {
if let Some(raw_comment) = self.comment() {
let comment =
comment::preprocess(raw_comment, codegen_depth + 1);
field = attributes::doc(comment);
}
}
let field_name = self
.name()
.map(|name| ctx.rust_mangle(name).into_owned())
.expect("Each field should have a name in codegen!");
let field_ident = ctx.rust_ident_raw(field_name.as_str());
if let Some(padding_field) =
struct_layout.saw_field(&field_name, field_ty, self.offset())
{
fields.extend(Some(padding_field));
}
let is_private = (!self.is_public() &&
ctx.options().respect_cxx_access_specs) ||
self.annotations()
.private_fields()
.unwrap_or(fields_should_be_private);
let accessor_kind =
self.annotations().accessor_kind().unwrap_or(accessor_kind);
if is_private {
field.append_all(quote! {
#field_ident : #ty ,
});
} else {
field.append_all(quote! {
pub #field_ident : #ty ,
});
}
fields.extend(Some(field));
// TODO: Factor the following code out, please!
if accessor_kind == FieldAccessorKind::None {
return;
}
let getter_name = ctx.rust_ident_raw(format!("get_{}", field_name));
let mutable_getter_name =
ctx.rust_ident_raw(format!("get_{}_mut", field_name));
let field_name = ctx.rust_ident_raw(field_name);
methods.extend(Some(match accessor_kind {
FieldAccessorKind::None => unreachable!(),
FieldAccessorKind::Regular => {
quote! {
#[inline]
pub fn #getter_name(&self) -> & #ty {
&self.#field_name
}
#[inline]
pub fn #mutable_getter_name(&mut self) -> &mut #ty {
&mut self.#field_name
}
}
}
FieldAccessorKind::Unsafe => {
quote! {
#[inline]
pub unsafe fn #getter_name(&self) -> & #ty {
&self.#field_name
}
#[inline]
pub unsafe fn #mutable_getter_name(&mut self) -> &mut #ty {
&mut self.#field_name
}
}
}
FieldAccessorKind::Immutable => {
quote! {
#[inline]
pub fn #getter_name(&self) -> & #ty {
&self.#field_name
}
}
}
}));
}
}
impl BitfieldUnit {
/// Get the constructor name for this bitfield unit.
fn ctor_name(&self) -> proc_macro2::TokenStream {
let ctor_name = Ident::new(
&format!("new_bitfield_{}", self.nth()),
Span::call_site(),
);
quote! {
#ctor_name
}
}
}
impl Bitfield {
/// Extend an under construction bitfield unit constructor with this
/// bitfield. This sets the relevant bits on the `__bindgen_bitfield_unit`
/// variable that's being constructed.
fn extend_ctor_impl(
&self,
ctx: &BindgenContext,
param_name: proc_macro2::TokenStream,
mut ctor_impl: proc_macro2::TokenStream,
) -> proc_macro2::TokenStream {
let bitfield_ty = ctx.resolve_type(self.ty());
let bitfield_ty_layout = bitfield_ty
.layout(ctx)
.expect("Bitfield without layout? Gah!");
let bitfield_int_ty = helpers::integer_type(ctx, bitfield_ty_layout)
.expect(
"Should already have verified that the bitfield is \
representable as an int",
);
let offset = self.offset_into_unit();
let width = self.width() as u8;
let prefix = ctx.trait_prefix();
ctor_impl.append_all(quote! {
__bindgen_bitfield_unit.set(
#offset,
#width,
{
let #param_name: #bitfield_int_ty = unsafe {
::#prefix::mem::transmute(#param_name)
};
#param_name as u64
}
);
});
ctor_impl
}
}
fn access_specifier(
ctx: &BindgenContext,
is_pub: bool,
) -> proc_macro2::TokenStream {
if is_pub || !ctx.options().respect_cxx_access_specs {
quote! { pub }
} else {
quote! {}
}
}
impl<'a> FieldCodegen<'a> for BitfieldUnit {
type Extra = ();
fn codegen<F, M>(
&self,
ctx: &BindgenContext,
fields_should_be_private: bool,
codegen_depth: usize,
accessor_kind: FieldAccessorKind,
parent: &CompInfo,
result: &mut CodegenResult,
struct_layout: &mut StructLayoutTracker,
fields: &mut F,
methods: &mut M,
_: (),
) where
F: Extend<proc_macro2::TokenStream>,
M: Extend<proc_macro2::TokenStream>,
{
use crate::ir::ty::RUST_DERIVE_IN_ARRAY_LIMIT;
result.saw_bitfield_unit();
let layout = self.layout();
let unit_field_ty = helpers::bitfield_unit(ctx, layout);
let field_ty = {
if parent.is_union() && !struct_layout.is_rust_union() {
result.saw_bindgen_union();
if ctx.options().enable_cxx_namespaces {
quote! {
root::__BindgenUnionField<#unit_field_ty>
}
} else {
quote! {
__BindgenUnionField<#unit_field_ty>
}
}
} else {
unit_field_ty.clone()
}
};
{
let align_field_name = format!("_bitfield_align_{}", self.nth());
let align_field_ident = ctx.rust_ident(&align_field_name);
let align_ty = match self.layout().align {
n if n >= 8 => quote! { u64 },
4 => quote! { u32 },
2 => quote! { u16 },
_ => quote! { u8 },
};
let align_field = quote! {
pub #align_field_ident: [#align_ty; 0],
};
fields.extend(Some(align_field));
}
let unit_field_name = format!("_bitfield_{}", self.nth());
let unit_field_ident = ctx.rust_ident(&unit_field_name);
let ctor_name = self.ctor_name();
let mut ctor_params = vec![];
let mut ctor_impl = quote! {};
// We cannot generate any constructor if the underlying storage can't
// implement AsRef<[u8]> / AsMut<[u8]> / etc, or can't derive Default.
//
// We don't check `larger_arrays` here because Default does still have
// the 32 items limitation.
let mut generate_ctor = layout.size <= RUST_DERIVE_IN_ARRAY_LIMIT;
let mut access_spec = !fields_should_be_private;
for bf in self.bitfields() {
// Codegen not allowed for anonymous bitfields
if bf.name().is_none() {
continue;
}
if layout.size > RUST_DERIVE_IN_ARRAY_LIMIT &&
!ctx.options().rust_features().larger_arrays
{
continue;
}
access_spec &= bf.is_public();
let mut bitfield_representable_as_int = true;
bf.codegen(
ctx,
fields_should_be_private,
codegen_depth,
accessor_kind,
parent,
result,
struct_layout,
fields,
methods,
(&unit_field_name, &mut bitfield_representable_as_int),
);
// Generating a constructor requires the bitfield to be representable as an integer.
if !bitfield_representable_as_int {
generate_ctor = false;
continue;
}
let param_name = bitfield_getter_name(ctx, bf);
let bitfield_ty_item = ctx.resolve_item(bf.ty());
let bitfield_ty = bitfield_ty_item.expect_type();
let bitfield_ty =
bitfield_ty.to_rust_ty_or_opaque(ctx, bitfield_ty_item);
ctor_params.push(quote! {
#param_name : #bitfield_ty
});
ctor_impl = bf.extend_ctor_impl(ctx, param_name, ctor_impl);
}
let access_spec = access_specifier(ctx, access_spec);
let field = quote! {
#access_spec #unit_field_ident : #field_ty ,
};
fields.extend(Some(field));
if generate_ctor {
methods.extend(Some(quote! {
#[inline]
#access_spec fn #ctor_name ( #( #ctor_params ),* ) -> #unit_field_ty {
let mut __bindgen_bitfield_unit: #unit_field_ty = Default::default();
#ctor_impl
__bindgen_bitfield_unit
}
}));
}
struct_layout.saw_bitfield_unit(layout);
}
}
fn bitfield_getter_name(
ctx: &BindgenContext,
bitfield: &Bitfield,
) -> proc_macro2::TokenStream {
let name = bitfield.getter_name();
let name = ctx.rust_ident_raw(name);
quote! { #name }
}
fn bitfield_setter_name(
ctx: &BindgenContext,
bitfield: &Bitfield,
) -> proc_macro2::TokenStream {
let setter = bitfield.setter_name();
let setter = ctx.rust_ident_raw(setter);
quote! { #setter }
}
impl<'a> FieldCodegen<'a> for Bitfield {
type Extra = (&'a str, &'a mut bool);
fn codegen<F, M>(
&self,
ctx: &BindgenContext,
fields_should_be_private: bool,
_codegen_depth: usize,
_accessor_kind: FieldAccessorKind,
parent: &CompInfo,
_result: &mut CodegenResult,
struct_layout: &mut StructLayoutTracker,
_fields: &mut F,
methods: &mut M,
(unit_field_name, bitfield_representable_as_int): (&'a str, &mut bool),
) where
F: Extend<proc_macro2::TokenStream>,
M: Extend<proc_macro2::TokenStream>,
{
let prefix = ctx.trait_prefix();
let getter_name = bitfield_getter_name(ctx, self);
let setter_name = bitfield_setter_name(ctx, self);
let unit_field_ident = Ident::new(unit_field_name, Span::call_site());
let bitfield_ty_item = ctx.resolve_item(self.ty());
let bitfield_ty = bitfield_ty_item.expect_type();
let bitfield_ty_layout = bitfield_ty
.layout(ctx)
.expect("Bitfield without layout? Gah!");
let bitfield_int_ty =
match helpers::integer_type(ctx, bitfield_ty_layout) {
Some(int_ty) => {
*bitfield_representable_as_int = true;
int_ty
}
None => {
*bitfield_representable_as_int = false;
return;
}
};
let bitfield_ty =
bitfield_ty.to_rust_ty_or_opaque(ctx, bitfield_ty_item);
let offset = self.offset_into_unit();
let width = self.width() as u8;
let access_spec = access_specifier(
ctx,
self.is_public() && !fields_should_be_private,
);
if parent.is_union() && !struct_layout.is_rust_union() {
methods.extend(Some(quote! {
#[inline]
#access_spec fn #getter_name(&self) -> #bitfield_ty {
unsafe {
::#prefix::mem::transmute(
self.#unit_field_ident.as_ref().get(#offset, #width)
as #bitfield_int_ty
)
}
}
#[inline]
#access_spec fn #setter_name(&mut self, val: #bitfield_ty) {
unsafe {
let val: #bitfield_int_ty = ::#prefix::mem::transmute(val);
self.#unit_field_ident.as_mut().set(
#offset,
#width,
val as u64
)
}
}
}));
} else {
methods.extend(Some(quote! {
#[inline]
#access_spec fn #getter_name(&self) -> #bitfield_ty {
unsafe {
::#prefix::mem::transmute(
self.#unit_field_ident.get(#offset, #width)
as #bitfield_int_ty
)
}
}
#[inline]
#access_spec fn #setter_name(&mut self, val: #bitfield_ty) {
unsafe {
let val: #bitfield_int_ty = ::#prefix::mem::transmute(val);
self.#unit_field_ident.set(
#offset,
#width,
val as u64
)
}
}
}));
}
}
}
impl CodeGenerator for CompInfo {
type Extra = Item;
type Return = ();
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
item: &Item,
) {
debug!("<CompInfo as CodeGenerator>::codegen: item = {:?}", item);
debug_assert!(item.is_enabled_for_codegen(ctx));
// Don't output classes with template parameters that aren't types, and
// also don't output template specializations, neither total or partial.
if self.has_non_type_template_params() {
return;
}
let ty = item.expect_type();
let layout = ty.layout(ctx);
let mut packed = self.is_packed(ctx, layout.as_ref());
let canonical_name = item.canonical_name(ctx);
let canonical_ident = ctx.rust_ident(&canonical_name);
// Generate the vtable from the method list if appropriate.
//
// TODO: I don't know how this could play with virtual methods that are
// not in the list of methods found by us, we'll see. Also, could the
// order of the vtable pointers vary?
//
// FIXME: Once we generate proper vtables, we need to codegen the
// vtable, but *not* generate a field for it in the case that
// HasVtable::has_vtable_ptr is false but HasVtable::has_vtable is true.
//
// Also, we need to generate the vtable in such a way it "inherits" from
// the parent too.
let is_opaque = item.is_opaque(ctx, &());
let mut fields = vec![];
let mut struct_layout =
StructLayoutTracker::new(ctx, self, ty, &canonical_name);
if !is_opaque {
if item.has_vtable_ptr(ctx) {
let vtable =
Vtable::new(item.id(), self.methods(), self.base_members());
vtable.codegen(ctx, result, item);
let vtable_type = vtable
.try_to_rust_ty(ctx, &())
.expect("vtable to Rust type conversion is infallible")
.to_ptr(true);
fields.push(quote! {
pub vtable_: #vtable_type ,
});
struct_layout.saw_vtable();
}
for base in self.base_members() {
if !base.requires_storage(ctx) {
continue;
}
let inner_item = ctx.resolve_item(base.ty);
let mut inner = inner_item.to_rust_ty_or_opaque(ctx, &());
inner.append_implicit_template_params(ctx, &inner_item);
let field_name = ctx.rust_ident(&base.field_name);
struct_layout.saw_base(inner_item.expect_type());
let access_spec = access_specifier(ctx, base.is_public());
fields.push(quote! {
#access_spec #field_name: #inner,
});
}
}
let mut methods = vec![];
if !is_opaque {
let codegen_depth = item.codegen_depth(ctx);
let fields_should_be_private =
item.annotations().private_fields().unwrap_or(false);
let struct_accessor_kind = item
.annotations()
.accessor_kind()
.unwrap_or(FieldAccessorKind::None);
for field in self.fields() {
field.codegen(
ctx,
fields_should_be_private,
codegen_depth,
struct_accessor_kind,
self,
result,
&mut struct_layout,
&mut fields,
&mut methods,
(),
);
}
// Check whether an explicit padding field is needed
// at the end.
if let Some(comp_layout) = layout {
fields.extend(
struct_layout
.add_tail_padding(&canonical_name, comp_layout),
);
}
}
if is_opaque {
// Opaque item should not have generated methods, fields.
debug_assert!(fields.is_empty());
debug_assert!(methods.is_empty());
}
let is_union = self.kind() == CompKind::Union;
let layout = item.kind().expect_type().layout(ctx);
let zero_sized = item.is_zero_sized(ctx);
let forward_decl = self.is_forward_declaration();
let mut explicit_align = None;
// C++ requires every struct to be addressable, so what C++ compilers do
// is making the struct 1-byte sized.
//
// This is apparently not the case for C, see:
// https://github.com/rust-lang/rust-bindgen/issues/551
//
// Just get the layout, and assume C++ if not.
//
// NOTE: This check is conveniently here to avoid the dummy fields we
// may add for unused template parameters.
if !forward_decl && zero_sized {
let has_address = if is_opaque {
// Generate the address field if it's an opaque type and
// couldn't determine the layout of the blob.
layout.is_none()
} else {
layout.map_or(true, |l| l.size != 0)
};
if has_address {
let layout = Layout::new(1, 1);
let ty = helpers::blob(ctx, Layout::new(1, 1));
struct_layout.saw_field_with_layout(
"_address",
layout,
/* offset = */ Some(0),
);
fields.push(quote! {
pub _address: #ty,
});
}
}
if is_opaque {
match layout {
Some(l) => {
explicit_align = Some(l.align);
let ty = helpers::blob(ctx, l);
fields.push(quote! {
pub _bindgen_opaque_blob: #ty ,
});
}
None => {
warn!("Opaque type without layout! Expect dragons!");
}
}
} else if !is_union && !zero_sized {
if let Some(padding_field) =
layout.and_then(|layout| struct_layout.pad_struct(layout))
{
fields.push(padding_field);
}
if let Some(layout) = layout {
if struct_layout.requires_explicit_align(layout) {
if layout.align == 1 {
packed = true;
} else {
explicit_align = Some(layout.align);
if !ctx.options().rust_features.repr_align {
let ty = helpers::blob(
ctx,
Layout::new(0, layout.align),
);
fields.push(quote! {
pub __bindgen_align: #ty ,
});
}
}
}
}
} else if is_union && !forward_decl {
// TODO(emilio): It'd be nice to unify this with the struct path
// above somehow.
let layout = layout.expect("Unable to get layout information?");
if struct_layout.requires_explicit_align(layout) {
explicit_align = Some(layout.align);
}
if !struct_layout.is_rust_union() {
let ty = helpers::blob(ctx, layout);
fields.push(quote! {
pub bindgen_union_field: #ty ,
})
}
}
if forward_decl {
fields.push(quote! {
_unused: [u8; 0],
});
}
let mut generic_param_names = vec![];
for (idx, ty) in item.used_template_params(ctx).iter().enumerate() {
let param = ctx.resolve_type(*ty);
let name = param.name().unwrap();
let ident = ctx.rust_ident(name);
generic_param_names.push(ident.clone());
let prefix = ctx.trait_prefix();
let field_name = ctx.rust_ident(format!("_phantom_{}", idx));
fields.push(quote! {
pub #field_name : ::#prefix::marker::PhantomData<
::#prefix::cell::UnsafeCell<#ident>
> ,
});
}
let generics = if !generic_param_names.is_empty() {
let generic_param_names = generic_param_names.clone();
quote! {
< #( #generic_param_names ),* >
}
} else {
quote! {}
};
let mut attributes = vec![];
let mut needs_clone_impl = false;
let mut needs_default_impl = false;
let mut needs_debug_impl = false;
let mut needs_partialeq_impl = false;
if let Some(comment) = item.comment(ctx) {
attributes.push(attributes::doc(comment));
}
if packed && !is_opaque {
let n = layout.map_or(1, |l| l.align);
assert!(ctx.options().rust_features().repr_packed_n || n == 1);
let packed_repr = if n == 1 {
"packed".to_string()
} else {
format!("packed({})", n)
};
attributes.push(attributes::repr_list(&["C", &packed_repr]));
} else {
attributes.push(attributes::repr("C"));
}
if ctx.options().rust_features().repr_align {
if let Some(explicit) = explicit_align {
// Ensure that the struct has the correct alignment even in
// presence of alignas.
let explicit = helpers::ast_ty::int_expr(explicit as i64);
attributes.push(quote! {
#[repr(align(#explicit))]
});
}
}
let derivable_traits = derives_of_item(item, ctx);
if !derivable_traits.contains(DerivableTraits::DEBUG) {
needs_debug_impl = ctx.options().derive_debug &&
ctx.options().impl_debug &&
!ctx.no_debug_by_name(item) &&
!item.annotations().disallow_debug();
}
if !derivable_traits.contains(DerivableTraits::DEFAULT) {
needs_default_impl = ctx.options().derive_default &&
!self.is_forward_declaration() &&
!ctx.no_default_by_name(item) &&
!item.annotations().disallow_default();
}
let all_template_params = item.all_template_params(ctx);
if derivable_traits.contains(DerivableTraits::COPY) &&
!derivable_traits.contains(DerivableTraits::CLONE)
{
needs_clone_impl = true;
}
if !derivable_traits.contains(DerivableTraits::PARTIAL_EQ) {
needs_partialeq_impl = ctx.options().derive_partialeq &&
ctx.options().impl_partialeq &&
ctx.lookup_can_derive_partialeq_or_partialord(item.id()) ==
CanDerive::Manually;
}
let mut derives: Vec<_> = derivable_traits.into();
derives.extend(item.annotations().derives().iter().map(String::as_str));
// The custom derives callback may return a list of derive attributes;
// add them to the end of the list.
let custom_derives;
if let Some(cb) = &ctx.options().parse_callbacks {
custom_derives = cb.add_derives(&canonical_name);
// In most cases this will be a no-op, since custom_derives will be empty.
derives.extend(custom_derives.iter().map(|s| s.as_str()));
};
if !derives.is_empty() {
attributes.push(attributes::derives(&derives))
}
if item.annotations().must_use_type() || ctx.must_use_type_by_name(item)
{
attributes.push(attributes::must_use());
}
let mut tokens = if is_union && struct_layout.is_rust_union() {
quote! {
#( #attributes )*
pub union #canonical_ident
}
} else {
quote! {
#( #attributes )*
pub struct #canonical_ident
}
};
tokens.append_all(quote! {
#generics {
#( #fields )*
}
});
result.push(tokens);
// Generate the inner types and all that stuff.
//
// TODO: In the future we might want to be smart, and use nested
// modules, and whatnot.
for ty in self.inner_types() {
let child_item = ctx.resolve_item(*ty);
// assert_eq!(child_item.parent_id(), item.id());
child_item.codegen(ctx, result, &());
}
// NOTE: Some unexposed attributes (like alignment attributes) may
// affect layout, so we're bad and pray to the gods for avoid sending
// all the tests to shit when parsing things like max_align_t.
if self.found_unknown_attr() {
warn!(
"Type {} has an unknown attribute that may affect layout",
canonical_ident
);
}
if all_template_params.is_empty() {
if !is_opaque {
for var in self.inner_vars() {
ctx.resolve_item(*var).codegen(ctx, result, &());
}
}
if ctx.options().layout_tests && !self.is_forward_declaration() {
if let Some(layout) = layout {
let fn_name =
format!("bindgen_test_layout_{}", canonical_ident);
let fn_name = ctx.rust_ident_raw(fn_name);
let prefix = ctx.trait_prefix();
let size_of_expr = quote! {
::#prefix::mem::size_of::<#canonical_ident>()
};
let align_of_expr = quote! {
::#prefix::mem::align_of::<#canonical_ident>()
};
let size = layout.size;
let align = layout.align;
let check_struct_align = if align >
ctx.target_pointer_size() &&
!ctx.options().rust_features().repr_align
{
None
} else {
Some(quote! {
assert_eq!(#align_of_expr,
#align,
concat!("Alignment of ", stringify!(#canonical_ident)));
})
};
// FIXME when [issue #465](https://github.com/rust-lang/rust-bindgen/issues/465) ready
let too_many_base_vtables = self
.base_members()
.iter()
.filter(|base| base.ty.has_vtable(ctx))
.count() >
1;
let should_skip_field_offset_checks =
is_opaque || too_many_base_vtables;
let check_field_offset = if should_skip_field_offset_checks
{
vec![]
} else {
let asserts = self.fields()
.iter()
.filter_map(|field| match *field {
Field::DataMember(ref f) if f.name().is_some() => Some(f),
_ => None,
})
.flat_map(|field| {
let name = field.name().unwrap();
field.offset().and_then(|offset| {
let field_offset = offset / 8;
let field_name = ctx.rust_ident(name);
Some(quote! {
assert_eq!(
unsafe {
&(*(::#prefix::ptr::null::<#canonical_ident>())).#field_name as *const _ as usize
},
#field_offset,
concat!("Offset of field: ", stringify!(#canonical_ident), "::", stringify!(#field_name))
);
})
})
})
.collect::<Vec<proc_macro2::TokenStream>>();
asserts
};
let item = quote! {
#[test]
fn #fn_name() {
assert_eq!(#size_of_expr,
#size,
concat!("Size of: ", stringify!(#canonical_ident)));
#check_struct_align
#( #check_field_offset )*
}
};
result.push(item);
}
}
let mut method_names = Default::default();
if ctx.options().codegen_config.methods() {
for method in self.methods() {
assert!(method.kind() != MethodKind::Constructor);
method.codegen_method(
ctx,
&mut methods,
&mut method_names,
result,
self,
);
}
}
if ctx.options().codegen_config.constructors() {
for sig in self.constructors() {
Method::new(
MethodKind::Constructor,
*sig,
/* const */
false,
)
.codegen_method(
ctx,
&mut methods,
&mut method_names,
result,
self,
);
}
}
if ctx.options().codegen_config.destructors() {
if let Some((kind, destructor)) = self.destructor() {
debug_assert!(kind.is_destructor());
Method::new(kind, destructor, false).codegen_method(
ctx,
&mut methods,
&mut method_names,
result,
self,
);
}
}
}
// NB: We can't use to_rust_ty here since for opaque types this tries to
// use the specialization knowledge to generate a blob field.
let ty_for_impl = quote! {
#canonical_ident #generics
};
if needs_clone_impl {
result.push(quote! {
impl #generics Clone for #ty_for_impl {
fn clone(&self) -> Self { *self }
}
});
}
if needs_default_impl {
let prefix = ctx.trait_prefix();
let body = if ctx.options().rust_features().maybe_uninit {
quote! {
let mut s = ::#prefix::mem::MaybeUninit::<Self>::uninit();
unsafe {
::#prefix::ptr::write_bytes(s.as_mut_ptr(), 0, 1);
s.assume_init()
}
}
} else {
quote! {
unsafe {
let mut s: Self = ::#prefix::mem::uninitialized();
::#prefix::ptr::write_bytes(&mut s, 0, 1);
s
}
}
};
// Note we use `ptr::write_bytes()` instead of `mem::zeroed()` because the latter does
// not necessarily ensure padding bytes are zeroed. Some C libraries are sensitive to
// non-zero padding bytes, especially when forwards/backwards compatability is
// involved.
result.push(quote! {
impl #generics Default for #ty_for_impl {
fn default() -> Self {
#body
}
}
});
}
if needs_debug_impl {
let impl_ = impl_debug::gen_debug_impl(
ctx,
self.fields(),
item,
self.kind(),
);
let prefix = ctx.trait_prefix();
result.push(quote! {
impl #generics ::#prefix::fmt::Debug for #ty_for_impl {
#impl_
}
});
}
if needs_partialeq_impl {
if let Some(impl_) = impl_partialeq::gen_partialeq_impl(
ctx,
self,
item,
&ty_for_impl,
) {
let partialeq_bounds = if !generic_param_names.is_empty() {
let bounds = generic_param_names.iter().map(|t| {
quote! { #t: PartialEq }
});
quote! { where #( #bounds ),* }
} else {
quote! {}
};
let prefix = ctx.trait_prefix();
result.push(quote! {
impl #generics ::#prefix::cmp::PartialEq for #ty_for_impl #partialeq_bounds {
#impl_
}
});
}
}
if !methods.is_empty() {
result.push(quote! {
impl #generics #ty_for_impl {
#( #methods )*
}
});
}
}
}
trait MethodCodegen {
fn codegen_method<'a>(
&self,
ctx: &BindgenContext,
methods: &mut Vec<proc_macro2::TokenStream>,
method_names: &mut HashMap<String, usize>,
result: &mut CodegenResult<'a>,
parent: &CompInfo,
);
}
impl MethodCodegen for Method {
fn codegen_method<'a>(
&self,
ctx: &BindgenContext,
methods: &mut Vec<proc_macro2::TokenStream>,
method_names: &mut HashMap<String, usize>,
result: &mut CodegenResult<'a>,
_parent: &CompInfo,
) {
assert!({
let cc = &ctx.options().codegen_config;
match self.kind() {
MethodKind::Constructor => cc.constructors(),
MethodKind::Destructor => cc.destructors(),
MethodKind::VirtualDestructor { .. } => cc.destructors(),
MethodKind::Static |
MethodKind::Normal |
MethodKind::Virtual { .. } => cc.methods(),
}
});
// TODO(emilio): We could generate final stuff at least.
if self.is_virtual() {
return; // FIXME
}
// First of all, output the actual function.
let function_item = ctx.resolve_item(self.signature());
if !function_item.process_before_codegen(ctx, result) {
return;
}
let function = function_item.expect_function();
let times_seen = function.codegen(ctx, result, &function_item);
let times_seen = match times_seen {
Some(seen) => seen,
None => return,
};
let signature_item = ctx.resolve_item(function.signature());
let mut name = match self.kind() {
MethodKind::Constructor => "new".into(),
MethodKind::Destructor => "destruct".into(),
_ => function.name().to_owned(),
};
let signature = match *signature_item.expect_type().kind() {
TypeKind::Function(ref sig) => sig,
_ => panic!("How in the world?"),
};
if let (Abi::ThisCall, false) =
(signature.abi(), ctx.options().rust_features().thiscall_abi)
{
return;
}
// Do not generate variadic methods, since rust does not allow
// implementing them, and we don't do a good job at it anyway.
if signature.is_variadic() {
return;
}
let count = {
let count = method_names.entry(name.clone()).or_insert(0);
*count += 1;
*count - 1
};
if count != 0 {
name.push_str(&count.to_string());
}
let mut function_name = function_item.canonical_name(ctx);
if times_seen > 0 {
write!(&mut function_name, "{}", times_seen).unwrap();
}
let function_name = ctx.rust_ident(function_name);
let mut args = utils::fnsig_arguments(ctx, signature);
let mut ret = utils::fnsig_return_ty(ctx, signature);
if !self.is_static() && !self.is_constructor() {
args[0] = if self.is_const() {
quote! { &self }
} else {
quote! { &mut self }
};
}
// If it's a constructor, we always return `Self`, and we inject the
// "this" parameter, so there's no need to ask the user for it.
//
// Note that constructors in Clang are represented as functions with
// return-type = void.
if self.is_constructor() {
args.remove(0);
ret = quote! { -> Self };
}
let mut exprs =
helpers::ast_ty::arguments_from_signature(&signature, ctx);
let mut stmts = vec![];
// If it's a constructor, we need to insert an extra parameter with a
// variable called `__bindgen_tmp` we're going to create.
if self.is_constructor() {
let prefix = ctx.trait_prefix();
let tmp_variable_decl = if ctx
.options()
.rust_features()
.maybe_uninit
{
exprs[0] = quote! {
__bindgen_tmp.as_mut_ptr()
};
quote! {
let mut __bindgen_tmp = ::#prefix::mem::MaybeUninit::uninit()
}
} else {
exprs[0] = quote! {
&mut __bindgen_tmp
};
quote! {
let mut __bindgen_tmp = ::#prefix::mem::uninitialized()
}
};
stmts.push(tmp_variable_decl);
} else if !self.is_static() {
assert!(!exprs.is_empty());
exprs[0] = quote! {
self
};
};
let call = quote! {
#function_name (#( #exprs ),* )
};
stmts.push(call);
if self.is_constructor() {
stmts.push(if ctx.options().rust_features().maybe_uninit {
quote! {
__bindgen_tmp.assume_init()
}
} else {
quote! {
__bindgen_tmp
}
})
}
let block = quote! {
#( #stmts );*
};
let mut attrs = vec![];
attrs.push(attributes::inline());
if signature.must_use() &&
ctx.options().rust_features().must_use_function
{
attrs.push(attributes::must_use());
}
let name = ctx.rust_ident(&name);
methods.push(quote! {
#(#attrs)*
pub unsafe fn #name ( #( #args ),* ) #ret {
#block
}
});
}
}
/// A helper type that represents different enum variations.
#[derive(Copy, Clone, PartialEq, Debug)]
pub enum EnumVariation {
/// The code for this enum will use a Rust enum. Note that creating this in unsafe code
/// (including FFI) with an invalid value will invoke undefined behaviour, whether or not
/// its marked as non_exhaustive.
Rust {
/// Indicates whether the generated struct should be `#[non_exhaustive]`
non_exhaustive: bool,
},
/// The code for this enum will use a newtype
NewType {
/// Indicates whether the newtype will have bitwise operators
is_bitfield: bool,
},
/// The code for this enum will use consts
Consts,
/// The code for this enum will use a module containing consts
ModuleConsts,
}
impl EnumVariation {
fn is_rust(&self) -> bool {
match *self {
EnumVariation::Rust { .. } => true,
_ => false,
}
}
/// Both the `Const` and `ModuleConsts` variants will cause this to return
/// true.
fn is_const(&self) -> bool {
match *self {
EnumVariation::Consts | EnumVariation::ModuleConsts => true,
_ => false,
}
}
}
impl Default for EnumVariation {
fn default() -> EnumVariation {
EnumVariation::Consts
}
}
impl std::str::FromStr for EnumVariation {
type Err = std::io::Error;
/// Create a `EnumVariation` from a string.
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s {
"rust" => Ok(EnumVariation::Rust {
non_exhaustive: false,
}),
"rust_non_exhaustive" => Ok(EnumVariation::Rust {
non_exhaustive: true,
}),
"bitfield" => Ok(EnumVariation::NewType { is_bitfield: true }),
"consts" => Ok(EnumVariation::Consts),
"moduleconsts" => Ok(EnumVariation::ModuleConsts),
"newtype" => Ok(EnumVariation::NewType { is_bitfield: false }),
_ => Err(std::io::Error::new(
std::io::ErrorKind::InvalidInput,
concat!(
"Got an invalid EnumVariation. Accepted values ",
"are 'rust', 'rust_non_exhaustive', 'bitfield', 'consts',",
"'moduleconsts', and 'newtype'."
),
)),
}
}
}
/// A helper type to construct different enum variations.
enum EnumBuilder<'a> {
Rust {
codegen_depth: usize,
attrs: Vec<proc_macro2::TokenStream>,
ident: Ident,
tokens: proc_macro2::TokenStream,
emitted_any_variants: bool,
},
NewType {
codegen_depth: usize,
canonical_name: &'a str,
tokens: proc_macro2::TokenStream,
is_bitfield: bool,
},
Consts {
repr: proc_macro2::TokenStream,
variants: Vec<proc_macro2::TokenStream>,
codegen_depth: usize,
},
ModuleConsts {
codegen_depth: usize,
module_name: &'a str,
module_items: Vec<proc_macro2::TokenStream>,
},
}
impl<'a> EnumBuilder<'a> {
/// Returns the depth of the code generation for a variant of this enum.
fn codegen_depth(&self) -> usize {
match *self {
EnumBuilder::Rust { codegen_depth, .. } |
EnumBuilder::NewType { codegen_depth, .. } |
EnumBuilder::ModuleConsts { codegen_depth, .. } |
EnumBuilder::Consts { codegen_depth, .. } => codegen_depth,
}
}
/// Returns true if the builder is for a rustified enum.
fn is_rust_enum(&self) -> bool {
match *self {
EnumBuilder::Rust { .. } => true,
_ => false,
}
}
/// Create a new enum given an item builder, a canonical name, a name for
/// the representation, and which variation it should be generated as.
fn new(
name: &'a str,
mut attrs: Vec<proc_macro2::TokenStream>,
repr: proc_macro2::TokenStream,
enum_variation: EnumVariation,
enum_codegen_depth: usize,
) -> Self {
let ident = Ident::new(name, Span::call_site());
match enum_variation {
EnumVariation::NewType { is_bitfield } => EnumBuilder::NewType {
codegen_depth: enum_codegen_depth,
canonical_name: name,
tokens: quote! {
#( #attrs )*
pub struct #ident (pub #repr);
},
is_bitfield,
},
EnumVariation::Rust { .. } => {
// `repr` is guaranteed to be Rustified in Enum::codegen
attrs.insert(0, quote! { #[repr( #repr )] });
let tokens = quote!();
EnumBuilder::Rust {
codegen_depth: enum_codegen_depth + 1,
attrs,
ident,
tokens,
emitted_any_variants: false,
}
}
EnumVariation::Consts => {
let mut variants = Vec::new();
variants.push(quote! {
#( #attrs )*
pub type #ident = #repr;
});
EnumBuilder::Consts {
repr,
variants,
codegen_depth: enum_codegen_depth,
}
}
EnumVariation::ModuleConsts => {
let ident = Ident::new(
CONSTIFIED_ENUM_MODULE_REPR_NAME,
Span::call_site(),
);
let type_definition = quote! {
#( #attrs )*
pub type #ident = #repr;
};
EnumBuilder::ModuleConsts {
codegen_depth: enum_codegen_depth + 1,
module_name: name,
module_items: vec![type_definition],
}
}
}
}
/// Add a variant to this enum.
fn with_variant<'b>(
self,
ctx: &BindgenContext,
variant: &EnumVariant,
mangling_prefix: Option<&str>,
rust_ty: proc_macro2::TokenStream,
result: &mut CodegenResult<'b>,
is_ty_named: bool,
) -> Self {
let variant_name = ctx.rust_mangle(variant.name());
let is_rust_enum = self.is_rust_enum();
let expr = match variant.val() {
EnumVariantValue::Boolean(v) if is_rust_enum => {
helpers::ast_ty::uint_expr(v as u64)
}
EnumVariantValue::Boolean(v) => quote!(#v),
EnumVariantValue::Signed(v) => helpers::ast_ty::int_expr(v),
EnumVariantValue::Unsigned(v) => helpers::ast_ty::uint_expr(v),
};
let mut doc = quote! {};
if ctx.options().generate_comments {
if let Some(raw_comment) = variant.comment() {
let comment =
comment::preprocess(raw_comment, self.codegen_depth());
doc = attributes::doc(comment);
}
}
match self {
EnumBuilder::Rust {
attrs,
ident,
tokens,
emitted_any_variants: _,
codegen_depth,
} => {
let name = ctx.rust_ident(variant_name);
EnumBuilder::Rust {
attrs,
ident,
codegen_depth,
tokens: quote! {
#tokens
#doc
#name = #expr,
},
emitted_any_variants: true,
}
}
EnumBuilder::NewType { canonical_name, .. } => {
if ctx.options().rust_features().associated_const && is_ty_named
{
let enum_ident = ctx.rust_ident(canonical_name);
let variant_ident = ctx.rust_ident(variant_name);
result.push(quote! {
impl #enum_ident {
#doc
pub const #variant_ident : #rust_ty = #rust_ty ( #expr );
}
});
} else {
let ident = ctx.rust_ident(match mangling_prefix {
Some(prefix) => {
Cow::Owned(format!("{}_{}", prefix, variant_name))
}
None => variant_name,
});
result.push(quote! {
#doc
pub const #ident : #rust_ty = #rust_ty ( #expr );
});
}
self
}
EnumBuilder::Consts { ref repr, .. } => {
let constant_name = match mangling_prefix {
Some(prefix) => {
Cow::Owned(format!("{}_{}", prefix, variant_name))
}
None => variant_name,
};
let ty = if is_ty_named { &rust_ty } else { repr };
let ident = ctx.rust_ident(constant_name);
result.push(quote! {
#doc
pub const #ident : #ty = #expr ;
});
self
}
EnumBuilder::ModuleConsts {
codegen_depth,
module_name,
mut module_items,
} => {
let name = ctx.rust_ident(variant_name);
let ty = ctx.rust_ident(CONSTIFIED_ENUM_MODULE_REPR_NAME);
module_items.push(quote! {
#doc
pub const #name : #ty = #expr ;
});
EnumBuilder::ModuleConsts {
module_name,
module_items,
codegen_depth,
}
}
}
}
fn build<'b>(
self,
ctx: &BindgenContext,
rust_ty: proc_macro2::TokenStream,
result: &mut CodegenResult<'b>,
) -> proc_macro2::TokenStream {
match self {
EnumBuilder::Rust {
attrs,
ident,
tokens,
emitted_any_variants,
..
} => {
let variants = if !emitted_any_variants {
quote!(__bindgen_cannot_repr_c_on_empty_enum = 0)
} else {
tokens
};
quote! {
#( #attrs )*
pub enum #ident {
#variants
}
}
}
EnumBuilder::NewType {
canonical_name,
tokens,
is_bitfield,
..
} => {
if !is_bitfield {
return tokens;
}
let rust_ty_name = ctx.rust_ident_raw(canonical_name);
let prefix = ctx.trait_prefix();
result.push(quote! {
impl ::#prefix::ops::BitOr<#rust_ty> for #rust_ty {
type Output = Self;
#[inline]
fn bitor(self, other: Self) -> Self {
#rust_ty_name(self.0 | other.0)
}
}
});
result.push(quote! {
impl ::#prefix::ops::BitOrAssign for #rust_ty {
#[inline]
fn bitor_assign(&mut self, rhs: #rust_ty) {
self.0 |= rhs.0;
}
}
});
result.push(quote! {
impl ::#prefix::ops::BitAnd<#rust_ty> for #rust_ty {
type Output = Self;
#[inline]
fn bitand(self, other: Self) -> Self {
#rust_ty_name(self.0 & other.0)
}
}
});
result.push(quote! {
impl ::#prefix::ops::BitAndAssign for #rust_ty {
#[inline]
fn bitand_assign(&mut self, rhs: #rust_ty) {
self.0 &= rhs.0;
}
}
});
tokens
}
EnumBuilder::Consts { variants, .. } => quote! { #( #variants )* },
EnumBuilder::ModuleConsts {
module_items,
module_name,
..
} => {
let ident = ctx.rust_ident(module_name);
quote! {
pub mod #ident {
#( #module_items )*
}
}
}
}
}
}
impl CodeGenerator for Enum {
type Extra = Item;
type Return = ();
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
item: &Item,
) {
debug!("<Enum as CodeGenerator>::codegen: item = {:?}", item);
debug_assert!(item.is_enabled_for_codegen(ctx));
let name = item.canonical_name(ctx);
let ident = ctx.rust_ident(&name);
let enum_ty = item.expect_type();
let layout = enum_ty.layout(ctx);
let variation = self.computed_enum_variation(ctx, item);
let repr_translated;
let repr = match self.repr().map(|repr| ctx.resolve_type(repr)) {
Some(repr)
if !ctx.options().translate_enum_integer_types &&
!variation.is_rust() =>
{
repr
}
repr => {
// An enum's integer type is translated to a native Rust
// integer type in 3 cases:
// * the enum is Rustified and we need a translated type for
// the repr attribute
// * the representation couldn't be determined from the C source
// * it was explicitly requested as a bindgen option
let kind = match repr {
Some(repr) => match *repr.canonical_type(ctx).kind() {
TypeKind::Int(int_kind) => int_kind,
_ => panic!("Unexpected type as enum repr"),
},
None => {
warn!(
"Guessing type of enum! Forward declarations of enums \
shouldn't be legal!"
);
IntKind::Int
}
};
let signed = kind.is_signed();
let size = layout
.map(|l| l.size)
.or_else(|| kind.known_size())
.unwrap_or(0);
let translated = match (signed, size) {
(true, 1) => IntKind::I8,
(false, 1) => IntKind::U8,
(true, 2) => IntKind::I16,
(false, 2) => IntKind::U16,
(true, 4) => IntKind::I32,
(false, 4) => IntKind::U32,
(true, 8) => IntKind::I64,
(false, 8) => IntKind::U64,
_ => {
warn!(
"invalid enum decl: signed: {}, size: {}",
signed, size
);
IntKind::I32
}
};
repr_translated =
Type::new(None, None, TypeKind::Int(translated), false);
&repr_translated
}
};
let mut attrs = vec![];
// TODO(emilio): Delegate this to the builders?
match variation {
EnumVariation::Rust { non_exhaustive } => {
if non_exhaustive &&
ctx.options().rust_features().non_exhaustive
{
attrs.push(attributes::non_exhaustive());
} else if non_exhaustive &&
!ctx.options().rust_features().non_exhaustive
{
panic!("The rust target you're using doesn't seem to support non_exhaustive enums");
}
}
EnumVariation::NewType { .. } => {
if ctx.options().rust_features.repr_transparent {
attrs.push(attributes::repr("transparent"));
} else {
attrs.push(attributes::repr("C"));
}
}
_ => {}
};
if let Some(comment) = item.comment(ctx) {
attrs.push(attributes::doc(comment));
}
if item.annotations().must_use_type() || ctx.must_use_type_by_name(item)
{
attrs.push(attributes::must_use());
}
if !variation.is_const() {
let mut derives = derives_of_item(item, ctx);
// For backwards compat, enums always derive Clone/Eq/PartialEq/Hash, even
// if we don't generate those by default.
derives.insert(
DerivableTraits::CLONE |
DerivableTraits::COPY |
DerivableTraits::HASH |
DerivableTraits::PARTIAL_EQ |
DerivableTraits::EQ,
);
let derives: Vec<_> = derives.into();
attrs.push(attributes::derives(&derives));
}
fn add_constant<'a>(
ctx: &BindgenContext,
enum_: &Type,
// Only to avoid recomputing every time.
enum_canonical_name: &Ident,
// May be the same as "variant" if it's because the
// enum is unnamed and we still haven't seen the
// value.
variant_name: &Ident,
referenced_name: &Ident,
enum_rust_ty: proc_macro2::TokenStream,
result: &mut CodegenResult<'a>,
) {
let constant_name = if enum_.name().is_some() {
if ctx.options().prepend_enum_name {
format!("{}_{}", enum_canonical_name, variant_name)
} else {
format!("{}", variant_name)
}
} else {
format!("{}", variant_name)
};
let constant_name = ctx.rust_ident(constant_name);
result.push(quote! {
pub const #constant_name : #enum_rust_ty =
#enum_canonical_name :: #referenced_name ;
});
}
let repr = repr.to_rust_ty_or_opaque(ctx, item);
let mut builder = EnumBuilder::new(
&name,
attrs,
repr,
variation,
item.codegen_depth(ctx),
);
// A map where we keep a value -> variant relation.
let mut seen_values = HashMap::<_, Ident>::default();
let enum_rust_ty = item.to_rust_ty_or_opaque(ctx, &());
let is_toplevel = item.is_toplevel(ctx);
// Used to mangle the constants we generate in the unnamed-enum case.
let parent_canonical_name = if is_toplevel {
None
} else {
Some(item.parent_id().canonical_name(ctx))
};
let constant_mangling_prefix = if ctx.options().prepend_enum_name {
if enum_ty.name().is_none() {
parent_canonical_name.as_ref().map(|n| &**n)
} else {
Some(&*name)
}
} else {
None
};
// NB: We defer the creation of constified variants, in case we find
// another variant with the same value (which is the common thing to
// do).
let mut constified_variants = VecDeque::new();
let mut iter = self.variants().iter().peekable();
while let Some(variant) =
iter.next().or_else(|| constified_variants.pop_front())
{
if variant.hidden() {
continue;
}
if variant.force_constification() && iter.peek().is_some() {
constified_variants.push_back(variant);
continue;
}
match seen_values.entry(variant.val()) {
Entry::Occupied(ref entry) => {
if variation.is_rust() {
let variant_name = ctx.rust_mangle(variant.name());
let mangled_name =
if is_toplevel || enum_ty.name().is_some() {
variant_name
} else {
let parent_name =
parent_canonical_name.as_ref().unwrap();
Cow::Owned(format!(
"{}_{}",
parent_name, variant_name
))
};
let existing_variant_name = entry.get();
// Use associated constants for named enums.
if enum_ty.name().is_some() &&
ctx.options().rust_features().associated_const
{
let enum_canonical_name = &ident;
let variant_name =
ctx.rust_ident_raw(&*mangled_name);
result.push(quote! {
impl #enum_rust_ty {
pub const #variant_name : #enum_rust_ty =
#enum_canonical_name :: #existing_variant_name ;
}
});
} else {
add_constant(
ctx,
enum_ty,
&ident,
&Ident::new(&*mangled_name, Span::call_site()),
existing_variant_name,
enum_rust_ty.clone(),
result,
);
}
} else {
builder = builder.with_variant(
ctx,
variant,
constant_mangling_prefix,
enum_rust_ty.clone(),
result,
enum_ty.name().is_some(),
);
}
}
Entry::Vacant(entry) => {
builder = builder.with_variant(
ctx,
variant,
constant_mangling_prefix,
enum_rust_ty.clone(),
result,
enum_ty.name().is_some(),
);
let variant_name = ctx.rust_ident(variant.name());
// If it's an unnamed enum, or constification is enforced,
// we also generate a constant so it can be properly
// accessed.
if (variation.is_rust() && enum_ty.name().is_none()) ||
variant.force_constification()
{
let mangled_name = if is_toplevel {
variant_name.clone()
} else {
let parent_name =
parent_canonical_name.as_ref().unwrap();
Ident::new(
&format!("{}_{}", parent_name, variant_name),
Span::call_site(),
)
};
add_constant(
ctx,
enum_ty,
&ident,
&mangled_name,
&variant_name,
enum_rust_ty.clone(),
result,
);
}
entry.insert(variant_name);
}
}
}
let item = builder.build(ctx, enum_rust_ty, result);
result.push(item);
}
}
/// Enum for the default type of macro constants.
#[derive(Copy, Clone, PartialEq, Debug)]
pub enum MacroTypeVariation {
/// Use i32 or i64
Signed,
/// Use u32 or u64
Unsigned,
}
impl MacroTypeVariation {
/// Convert a `MacroTypeVariation` to its str representation.
pub fn as_str(&self) -> &str {
match self {
MacroTypeVariation::Signed => "signed",
MacroTypeVariation::Unsigned => "unsigned",
}
}
}
impl Default for MacroTypeVariation {
fn default() -> MacroTypeVariation {
MacroTypeVariation::Unsigned
}
}
impl std::str::FromStr for MacroTypeVariation {
type Err = std::io::Error;
/// Create a `MacroTypeVariation` from a string.
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s {
"signed" => Ok(MacroTypeVariation::Signed),
"unsigned" => Ok(MacroTypeVariation::Unsigned),
_ => Err(std::io::Error::new(
std::io::ErrorKind::InvalidInput,
concat!(
"Got an invalid MacroTypeVariation. Accepted values ",
"are 'signed' and 'unsigned'"
),
)),
}
}
}
/// Enum for how aliases should be translated.
#[derive(Copy, Clone, PartialEq, Debug)]
pub enum AliasVariation {
/// Convert to regular Rust alias
TypeAlias,
/// Create a new type by wrapping the old type in a struct and using #[repr(transparent)]
NewType,
/// Same as NewStruct but also impl Deref to be able to use the methods of the wrapped type
NewTypeDeref,
}
impl AliasVariation {
/// Convert an `AliasVariation` to its str representation.
pub fn as_str(&self) -> &str {
match self {
AliasVariation::TypeAlias => "type_alias",
AliasVariation::NewType => "new_type",
AliasVariation::NewTypeDeref => "new_type_deref",
}
}
}
impl Default for AliasVariation {
fn default() -> AliasVariation {
AliasVariation::TypeAlias
}
}
impl std::str::FromStr for AliasVariation {
type Err = std::io::Error;
/// Create an `AliasVariation` from a string.
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s {
"type_alias" => Ok(AliasVariation::TypeAlias),
"new_type" => Ok(AliasVariation::NewType),
"new_type_deref" => Ok(AliasVariation::NewTypeDeref),
_ => Err(std::io::Error::new(
std::io::ErrorKind::InvalidInput,
concat!(
"Got an invalid AliasVariation. Accepted values ",
"are 'type_alias', 'new_type', and 'new_type_deref'"
),
)),
}
}
}
/// Fallible conversion to an opaque blob.
///
/// Implementors of this trait should provide the `try_get_layout` method to
/// fallibly get this thing's layout, which the provided `try_to_opaque` trait
/// method will use to convert the `Layout` into an opaque blob Rust type.
trait TryToOpaque {
type Extra;
/// Get the layout for this thing, if one is available.
fn try_get_layout(
&self,
ctx: &BindgenContext,
extra: &Self::Extra,
) -> error::Result<Layout>;
/// Do not override this provided trait method.
fn try_to_opaque(
&self,
ctx: &BindgenContext,
extra: &Self::Extra,
) -> error::Result<proc_macro2::TokenStream> {
self.try_get_layout(ctx, extra)
.map(|layout| helpers::blob(ctx, layout))
}
}
/// Infallible conversion of an IR thing to an opaque blob.
///
/// The resulting layout is best effort, and is unfortunately not guaranteed to
/// be correct. When all else fails, we fall back to a single byte layout as a
/// last resort, because C++ does not permit zero-sized types. See the note in
/// the `ToRustTyOrOpaque` doc comment about fallible versus infallible traits
/// and when each is appropriate.
///
/// Don't implement this directly. Instead implement `TryToOpaque`, and then
/// leverage the blanket impl for this trait.
trait ToOpaque: TryToOpaque {
fn get_layout(&self, ctx: &BindgenContext, extra: &Self::Extra) -> Layout {
self.try_get_layout(ctx, extra)
.unwrap_or_else(|_| Layout::for_size(ctx, 1))
}
fn to_opaque(
&self,
ctx: &BindgenContext,
extra: &Self::Extra,
) -> proc_macro2::TokenStream {
let layout = self.get_layout(ctx, extra);
helpers::blob(ctx, layout)
}
}
impl<T> ToOpaque for T where T: TryToOpaque {}
/// Fallible conversion from an IR thing to an *equivalent* Rust type.
///
/// If the C/C++ construct represented by the IR thing cannot (currently) be
/// represented in Rust (for example, instantiations of templates with
/// const-value generic parameters) then the impl should return an `Err`. It
/// should *not* attempt to return an opaque blob with the correct size and
/// alignment. That is the responsibility of the `TryToOpaque` trait.
trait TryToRustTy {
type Extra;
fn try_to_rust_ty(
&self,
ctx: &BindgenContext,
extra: &Self::Extra,
) -> error::Result<proc_macro2::TokenStream>;
}
/// Fallible conversion to a Rust type or an opaque blob with the correct size
/// and alignment.
///
/// Don't implement this directly. Instead implement `TryToRustTy` and
/// `TryToOpaque`, and then leverage the blanket impl for this trait below.
trait TryToRustTyOrOpaque: TryToRustTy + TryToOpaque {
type Extra;
fn try_to_rust_ty_or_opaque(
&self,
ctx: &BindgenContext,
extra: &<Self as TryToRustTyOrOpaque>::Extra,
) -> error::Result<proc_macro2::TokenStream>;
}
impl<E, T> TryToRustTyOrOpaque for T
where
T: TryToRustTy<Extra = E> + TryToOpaque<Extra = E>,
{
type Extra = E;
fn try_to_rust_ty_or_opaque(
&self,
ctx: &BindgenContext,
extra: &E,
) -> error::Result<proc_macro2::TokenStream> {
self.try_to_rust_ty(ctx, extra).or_else(|_| {
if let Ok(layout) = self.try_get_layout(ctx, extra) {
Ok(helpers::blob(ctx, layout))
} else {
Err(error::Error::NoLayoutForOpaqueBlob)
}
})
}
}
/// Infallible conversion to a Rust type, or an opaque blob with a best effort
/// of correct size and alignment.
///
/// Don't implement this directly. Instead implement `TryToRustTy` and
/// `TryToOpaque`, and then leverage the blanket impl for this trait below.
///
/// ### Fallible vs. Infallible Conversions to Rust Types
///
/// When should one use this infallible `ToRustTyOrOpaque` trait versus the
/// fallible `TryTo{RustTy, Opaque, RustTyOrOpaque}` triats? All fallible trait
/// implementations that need to convert another thing into a Rust type or
/// opaque blob in a nested manner should also use fallible trait methods and
/// propagate failure up the stack. Only infallible functions and methods like
/// CodeGenerator implementations should use the infallible
/// `ToRustTyOrOpaque`. The further out we push error recovery, the more likely
/// we are to get a usable `Layout` even if we can't generate an equivalent Rust
/// type for a C++ construct.
trait ToRustTyOrOpaque: TryToRustTy + ToOpaque {
type Extra;
fn to_rust_ty_or_opaque(
&self,
ctx: &BindgenContext,
extra: &<Self as ToRustTyOrOpaque>::Extra,
) -> proc_macro2::TokenStream;
}
impl<E, T> ToRustTyOrOpaque for T
where
T: TryToRustTy<Extra = E> + ToOpaque<Extra = E>,
{
type Extra = E;
fn to_rust_ty_or_opaque(
&self,
ctx: &BindgenContext,
extra: &E,
) -> proc_macro2::TokenStream {
self.try_to_rust_ty(ctx, extra)
.unwrap_or_else(|_| self.to_opaque(ctx, extra))
}
}
impl<T> TryToOpaque for T
where
T: Copy + Into<ItemId>,
{
type Extra = ();
fn try_get_layout(
&self,
ctx: &BindgenContext,
_: &(),
) -> error::Result<Layout> {
ctx.resolve_item((*self).into()).try_get_layout(ctx, &())
}
}
impl<T> TryToRustTy for T
where
T: Copy + Into<ItemId>,
{
type Extra = ();
fn try_to_rust_ty(
&self,
ctx: &BindgenContext,
_: &(),
) -> error::Result<proc_macro2::TokenStream> {
ctx.resolve_item((*self).into()).try_to_rust_ty(ctx, &())
}
}
impl TryToOpaque for Item {
type Extra = ();
fn try_get_layout(
&self,
ctx: &BindgenContext,
_: &(),
) -> error::Result<Layout> {
self.kind().expect_type().try_get_layout(ctx, self)
}
}
impl TryToRustTy for Item {
type Extra = ();
fn try_to_rust_ty(
&self,
ctx: &BindgenContext,
_: &(),
) -> error::Result<proc_macro2::TokenStream> {
self.kind().expect_type().try_to_rust_ty(ctx, self)
}
}
impl TryToOpaque for Type {
type Extra = Item;
fn try_get_layout(
&self,
ctx: &BindgenContext,
_: &Item,
) -> error::Result<Layout> {
self.layout(ctx).ok_or(error::Error::NoLayoutForOpaqueBlob)
}
}
impl TryToRustTy for Type {
type Extra = Item;
fn try_to_rust_ty(
&self,
ctx: &BindgenContext,
item: &Item,
) -> error::Result<proc_macro2::TokenStream> {
use self::helpers::ast_ty::*;
match *self.kind() {
TypeKind::Void => Ok(c_void(ctx)),
// TODO: we should do something smart with nullptr, or maybe *const
// c_void is enough?
TypeKind::NullPtr => Ok(c_void(ctx).to_ptr(true)),
TypeKind::Int(ik) => {
match ik {
IntKind::Bool => Ok(quote! { bool }),
IntKind::Char { .. } => Ok(raw_type(ctx, "c_char")),
IntKind::SChar => Ok(raw_type(ctx, "c_schar")),
IntKind::UChar => Ok(raw_type(ctx, "c_uchar")),
IntKind::Short => Ok(raw_type(ctx, "c_short")),
IntKind::UShort => Ok(raw_type(ctx, "c_ushort")),
IntKind::Int => Ok(raw_type(ctx, "c_int")),
IntKind::UInt => Ok(raw_type(ctx, "c_uint")),
IntKind::Long => Ok(raw_type(ctx, "c_long")),
IntKind::ULong => Ok(raw_type(ctx, "c_ulong")),
IntKind::LongLong => Ok(raw_type(ctx, "c_longlong")),
IntKind::ULongLong => Ok(raw_type(ctx, "c_ulonglong")),
IntKind::WChar => {
let layout = self
.layout(ctx)
.expect("Couldn't compute wchar_t's layout?");
let ty = Layout::known_type_for_size(ctx, layout.size)
.expect("Non-representable wchar_t?");
let ident = ctx.rust_ident_raw(ty);
Ok(quote! { #ident })
}
IntKind::I8 => Ok(quote! { i8 }),
IntKind::U8 => Ok(quote! { u8 }),
IntKind::I16 => Ok(quote! { i16 }),
IntKind::U16 => Ok(quote! { u16 }),
IntKind::I32 => Ok(quote! { i32 }),
IntKind::U32 => Ok(quote! { u32 }),
IntKind::I64 => Ok(quote! { i64 }),
IntKind::U64 => Ok(quote! { u64 }),
IntKind::Custom { name, .. } => {
Ok(proc_macro2::TokenStream::from_str(name).unwrap())
}
IntKind::U128 => {
Ok(if ctx.options().rust_features.i128_and_u128 {
quote! { u128 }
} else {
// Best effort thing, but wrong alignment
// unfortunately.
quote! { [u64; 2] }
})
}
IntKind::I128 => {
Ok(if ctx.options().rust_features.i128_and_u128 {
quote! { i128 }
} else {
quote! { [u64; 2] }
})
}
}
}
TypeKind::Float(fk) => {
Ok(float_kind_rust_type(ctx, fk, self.layout(ctx)))
}
TypeKind::Complex(fk) => {
let float_path =
float_kind_rust_type(ctx, fk, self.layout(ctx));
ctx.generated_bindgen_complex();
Ok(if ctx.options().enable_cxx_namespaces {
quote! {
root::__BindgenComplex<#float_path>
}
} else {
quote! {
__BindgenComplex<#float_path>
}
})
}
TypeKind::Function(ref fs) => {
// We can't rely on the sizeof(Option<NonZero<_>>) ==
// sizeof(NonZero<_>) optimization with opaque blobs (because
// they aren't NonZero), so don't *ever* use an or_opaque
// variant here.
let ty = fs.try_to_rust_ty(ctx, &())?;
let prefix = ctx.trait_prefix();
Ok(quote! {
::#prefix::option::Option<#ty>
})
}
TypeKind::Array(item, len) | TypeKind::Vector(item, len) => {
let ty = item.try_to_rust_ty(ctx, &())?;
Ok(quote! {
[ #ty ; #len ]
})
}
TypeKind::Enum(..) => {
let path = item.namespace_aware_canonical_path(ctx);
let path = proc_macro2::TokenStream::from_str(&path.join("::"))
.unwrap();
Ok(quote!(#path))
}
TypeKind::TemplateInstantiation(ref inst) => {
inst.try_to_rust_ty(ctx, item)
}
TypeKind::ResolvedTypeRef(inner) => inner.try_to_rust_ty(ctx, &()),
TypeKind::TemplateAlias(..) |
TypeKind::Alias(..) |
TypeKind::BlockPointer(..) => {
if self.is_block_pointer() && !ctx.options().generate_block {
let void = c_void(ctx);
return Ok(void.to_ptr(/* is_const = */ false));
}
let template_params = item
.used_template_params(ctx)
.into_iter()
.filter(|param| param.is_template_param(ctx, &()))
.collect::<Vec<_>>();
if item.is_opaque(ctx, &()) && !template_params.is_empty() {
self.try_to_opaque(ctx, item)
} else if let Some(ty) = self
.name()
.and_then(|name| utils::type_from_named(ctx, name))
{
Ok(ty)
} else {
utils::build_path(item, ctx)
}
}
TypeKind::Comp(ref info) => {
let template_params = item.all_template_params(ctx);
if info.has_non_type_template_params() ||
(item.is_opaque(ctx, &()) && !template_params.is_empty())
{
return self.try_to_opaque(ctx, item);
}
utils::build_path(item, ctx)
}
TypeKind::Opaque => self.try_to_opaque(ctx, item),
TypeKind::Pointer(inner) | TypeKind::Reference(inner) => {
let is_const = ctx.resolve_type(inner).is_const();
let inner =
inner.into_resolver().through_type_refs().resolve(ctx);
let inner_ty = inner.expect_type();
let is_objc_pointer = match inner_ty.kind() {
TypeKind::ObjCInterface(..) => true,
_ => false,
};
// Regardless if we can properly represent the inner type, we
// should always generate a proper pointer here, so use
// infallible conversion of the inner type.
let mut ty = inner.to_rust_ty_or_opaque(ctx, &());
ty.append_implicit_template_params(ctx, inner);
// Avoid the first function pointer level, since it's already
// represented in Rust.
if inner_ty.canonical_type(ctx).is_function() || is_objc_pointer
{
Ok(ty)
} else {
Ok(ty.to_ptr(is_const))
}
}
TypeKind::TypeParam => {
let name = item.canonical_name(ctx);
let ident = ctx.rust_ident(&name);
Ok(quote! {
#ident
})
}
TypeKind::ObjCSel => Ok(quote! {
objc::runtime::Sel
}),
TypeKind::ObjCId => Ok(quote! {
id
}),
TypeKind::ObjCInterface(ref interface) => {
let name = ctx.rust_ident(interface.name());
Ok(quote! {
#name
})
}
ref u @ TypeKind::UnresolvedTypeRef(..) => {
unreachable!("Should have been resolved after parsing {:?}!", u)
}
}
}
}
impl TryToOpaque for TemplateInstantiation {
type Extra = Item;
fn try_get_layout(
&self,
ctx: &BindgenContext,
item: &Item,
) -> error::Result<Layout> {
item.expect_type()
.layout(ctx)
.ok_or(error::Error::NoLayoutForOpaqueBlob)
}
}
impl TryToRustTy for TemplateInstantiation {
type Extra = Item;
fn try_to_rust_ty(
&self,
ctx: &BindgenContext,
item: &Item,
) -> error::Result<proc_macro2::TokenStream> {
if self.is_opaque(ctx, item) {
return Err(error::Error::InstantiationOfOpaqueType);
}
let def = self
.template_definition()
.into_resolver()
.through_type_refs()
.resolve(ctx);
let mut ty = quote! {};
let def_path = def.namespace_aware_canonical_path(ctx);
ty.append_separated(
def_path.into_iter().map(|p| ctx.rust_ident(p)),
quote!(::),
);
let def_params = def.self_template_params(ctx);
if def_params.is_empty() {
// This can happen if we generated an opaque type for a partial
// template specialization, and we've hit an instantiation of
// that partial specialization.
extra_assert!(def.is_opaque(ctx, &()));
return Err(error::Error::InstantiationOfOpaqueType);
}
// TODO: If the definition type is a template class/struct
// definition's member template definition, it could rely on
// generic template parameters from its outer template
// class/struct. When we emit bindings for it, it could require
// *more* type arguments than we have here, and we will need to
// reconstruct them somehow. We don't have any means of doing
// that reconstruction at this time.
let template_args = self
.template_arguments()
.iter()
.zip(def_params.iter())
// Only pass type arguments for the type parameters that
// the def uses.
.filter(|&(_, param)| ctx.uses_template_parameter(def.id(), *param))
.map(|(arg, _)| {
let arg = arg.into_resolver().through_type_refs().resolve(ctx);
let mut ty = arg.try_to_rust_ty(ctx, &())?;
ty.append_implicit_template_params(ctx, arg);
Ok(ty)
})
.collect::<error::Result<Vec<_>>>()?;
if template_args.is_empty() {
return Ok(ty);
}
Ok(quote! {
#ty < #( #template_args ),* >
})
}
}
impl TryToRustTy for FunctionSig {
type Extra = ();
fn try_to_rust_ty(
&self,
ctx: &BindgenContext,
_: &(),
) -> error::Result<proc_macro2::TokenStream> {
// TODO: we might want to consider ignoring the reference return value.
let ret = utils::fnsig_return_ty(ctx, &self);
let arguments = utils::fnsig_arguments(ctx, &self);
let abi = self.abi();
match abi {
Abi::ThisCall if !ctx.options().rust_features().thiscall_abi => {
warn!("Skipping function with thiscall ABI that isn't supported by the configured Rust target");
Ok(proc_macro2::TokenStream::new())
}
_ => Ok(quote! {
unsafe extern #abi fn ( #( #arguments ),* ) #ret
}),
}
}
}
impl CodeGenerator for Function {
type Extra = Item;
/// If we've actually generated the symbol, the number of times we've seen
/// it.
type Return = Option<u32>;
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
item: &Item,
) -> Self::Return {
debug!("<Function as CodeGenerator>::codegen: item = {:?}", item);
debug_assert!(item.is_enabled_for_codegen(ctx));
// We can't currently do anything with Internal functions so just
// avoid generating anything for them.
match self.linkage() {
Linkage::Internal => return None,
Linkage::External => {}
}
// Pure virtual methods have no actual symbol, so we can't generate
// something meaningful for them.
match self.kind() {
FunctionKind::Method(ref method_kind)
if method_kind.is_pure_virtual() =>
{
return None;
}
_ => {}
}
// Similar to static member variables in a class template, we can't
// generate bindings to template functions, because the set of
// instantiations is open ended and we have no way of knowing which
// monomorphizations actually exist.
if !item.all_template_params(ctx).is_empty() {
return None;
}
let name = self.name();
let mut canonical_name = item.canonical_name(ctx);
let mangled_name = self.mangled_name();
{
let seen_symbol_name = mangled_name.unwrap_or(&canonical_name);
// TODO: Maybe warn here if there's a type/argument mismatch, or
// something?
if result.seen_function(seen_symbol_name) {
return None;
}
result.saw_function(seen_symbol_name);
}
let signature_item = ctx.resolve_item(self.signature());
let signature = signature_item.kind().expect_type().canonical_type(ctx);
let signature = match *signature.kind() {
TypeKind::Function(ref sig) => sig,
_ => panic!("Signature kind is not a Function: {:?}", signature),
};
let args = utils::fnsig_arguments(ctx, signature);
let ret = utils::fnsig_return_ty(ctx, signature);
let mut attributes = vec![];
if signature.must_use() &&
ctx.options().rust_features().must_use_function
{
attributes.push(attributes::must_use());
}
if let Some(comment) = item.comment(ctx) {
attributes.push(attributes::doc(comment));
}
let abi = match signature.abi() {
Abi::ThisCall if !ctx.options().rust_features().thiscall_abi => {
warn!("Skipping function with thiscall ABI that isn't supported by the configured Rust target");
return None;
}
Abi::Win64 if signature.is_variadic() => {
warn!("Skipping variadic function with Win64 ABI that isn't supported");
return None;
}
Abi::Unknown(unknown_abi) => {
panic!(
"Invalid or unknown abi {:?} for function {:?} ({:?})",
unknown_abi, canonical_name, self
);
}
abi => abi,
};
// Handle overloaded functions by giving each overload its own unique
// suffix.
let times_seen = result.overload_number(&canonical_name);
if times_seen > 0 {
write!(&mut canonical_name, "{}", times_seen).unwrap();
}
let link_name = mangled_name.unwrap_or(name);
if !utils::names_will_be_identical_after_mangling(
&canonical_name,
link_name,
Some(abi),
) {
attributes.push(attributes::link_name(link_name));
}
// Unfortunately this can't piggyback on the `attributes` list because
// the #[link(wasm_import_module)] needs to happen before the `extern
// "C"` block. It doesn't get picked up properly otherwise
let wasm_link_attribute =
ctx.options().wasm_import_module_name.as_ref().map(|name| {
quote! { #[link(wasm_import_module = #name)] }
});
let ident = ctx.rust_ident(canonical_name);
let tokens = quote! {
#wasm_link_attribute
extern #abi {
#(#attributes)*
pub fn #ident ( #( #args ),* ) #ret;
}
};
// If we're doing dynamic binding generation, add to the dynamic items.
if ctx.options().dynamic_library_name.is_some() &&
self.kind() == FunctionKind::Function
{
let args_identifiers =
utils::fnsig_argument_identifiers(ctx, signature);
let return_item = ctx.resolve_item(signature.return_type());
let ret_ty = match *return_item.kind().expect_type().kind() {
TypeKind::Void => quote! {()},
_ => return_item.to_rust_ty_or_opaque(ctx, &()),
};
result.dynamic_items().push(
ident,
abi,
signature.is_variadic(),
ctx.options().dynamic_link_require_all,
args,
args_identifiers,
ret,
ret_ty,
);
} else {
result.push(tokens);
}
Some(times_seen)
}
}
fn objc_method_codegen(
ctx: &BindgenContext,
method: &ObjCMethod,
class_name: Option<&str>,
prefix: &str,
) -> proc_macro2::TokenStream {
let signature = method.signature();
let fn_args = utils::fnsig_arguments(ctx, signature);
let fn_ret = utils::fnsig_return_ty(ctx, signature);
let sig = if method.is_class_method() {
let fn_args = fn_args.clone();
quote! {
( #( #fn_args ),* ) #fn_ret
}
} else {
let fn_args = fn_args.clone();
let args = iter::once(quote! { &self }).chain(fn_args.into_iter());
quote! {
( #( #args ),* ) #fn_ret
}
};
let methods_and_args = method.format_method_call(&fn_args);
let body = if method.is_class_method() {
let class_name = ctx.rust_ident(
class_name
.expect("Generating a class method without class name?")
.to_owned(),
);
quote! {
msg_send!(class!(#class_name), #methods_and_args)
}
} else {
quote! {
msg_send!(*self, #methods_and_args)
}
};
let method_name =
ctx.rust_ident(format!("{}{}", prefix, method.rust_name()));
quote! {
unsafe fn #method_name #sig where <Self as std::ops::Deref>::Target: objc::Message + Sized {
#body
}
}
}
impl CodeGenerator for ObjCInterface {
type Extra = Item;
type Return = ();
fn codegen<'a>(
&self,
ctx: &BindgenContext,
result: &mut CodegenResult<'a>,
item: &Item,
) {
debug_assert!(item.is_enabled_for_codegen(ctx));
let mut impl_items = vec![];
for method in self.methods() {
let impl_item = objc_method_codegen(ctx, method, None, "");
impl_items.push(impl_item);
}
let instance_method_names: Vec<_> =
self.methods().iter().map(|m| m.rust_name()).collect();
for class_method in self.class_methods() {
let ambiquity =
instance_method_names.contains(&class_method.rust_name());
let prefix = if ambiquity { "class_" } else { "" };
let impl_item = objc_method_codegen(
ctx,
class_method,
Some(self.name()),
prefix,
);
impl_items.push(impl_item);
}
let trait_name = ctx.rust_ident(self.rust_name());
let trait_constraints = quote! {
Sized + std::ops::Deref
};
let trait_block = if self.is_template() {
let template_names: Vec<Ident> = self
.template_names
.iter()
.map(|g| ctx.rust_ident(g))
.collect();
quote! {
pub trait #trait_name <#(#template_names),*> : #trait_constraints {
#( #impl_items )*
}
}
} else {
quote! {
pub trait #trait_name : #trait_constraints {
#( #impl_items )*
}
}
};
let class_name = ctx.rust_ident(self.name());
if !self.is_category() && !self.is_protocol() {
let struct_block = quote! {
#[repr(transparent)]
#[derive(Clone)]
pub struct #class_name(pub id);
impl std::ops::Deref for #class_name {
type Target = objc::runtime::Object;
fn deref(&self) -> &Self::Target {
unsafe {
&*self.0
}
}
}
unsafe impl objc::Message for #class_name { }
impl #class_name {
pub fn alloc() -> Self {
Self(unsafe {
msg_send!(objc::class!(#class_name), alloc)
})
}
}
};
result.push(struct_block);
let mut protocol_set: HashSet<ItemId> = Default::default();
for protocol_id in self.conforms_to.iter() {
protocol_set.insert(*protocol_id);
let protocol_name = ctx.rust_ident(
ctx.resolve_type(protocol_id.expect_type_id(ctx))
.name()
.unwrap(),
);
let impl_trait = quote! {
impl #protocol_name for #class_name { }
};
result.push(impl_trait);
}
let mut parent_class = self.parent_class;
while let Some(parent_id) = parent_class {
let parent = parent_id
.expect_type_id(ctx)
.into_resolver()
.through_type_refs()
.resolve(ctx)
.expect_type()
.kind();
let parent = match parent {
TypeKind::ObjCInterface(ref parent) => parent,
_ => break,
};
parent_class = parent.parent_class;
let parent_name = ctx.rust_ident(parent.rust_name());
let impl_trait = if parent.is_template() {
let template_names: Vec<Ident> = parent
.template_names
.iter()
.map(|g| ctx.rust_ident(g))
.collect();
quote! {
impl <#(#template_names :'static),*> #parent_name <#(#template_names),*> for #class_name {
}
}
} else {
quote! {
impl #parent_name for #class_name { }
}
};
result.push(impl_trait);
for protocol_id in parent.conforms_to.iter() {
if protocol_set.insert(*protocol_id) {
let protocol_name = ctx.rust_ident(
ctx.resolve_type(protocol_id.expect_type_id(ctx))
.name()
.unwrap(),
);
let impl_trait = quote! {
impl #protocol_name for #class_name { }
};
result.push(impl_trait);
}
}
if !parent.is_template() {
let parent_struct_name = parent.name();
let child_struct_name = self.name();
let parent_struct = ctx.rust_ident(parent_struct_name);
let from_block = quote! {
impl From<#class_name> for #parent_struct {
fn from(child: #class_name) -> #parent_struct {
#parent_struct(child.0)
}
}
};
result.push(from_block);
let error_msg = format!(
"This {} cannot be downcasted to {}",
parent_struct_name, child_struct_name
);
let try_into_block = quote! {
impl std::convert::TryFrom<#parent_struct> for #class_name {
type Error = &'static str;
fn try_from(parent: #parent_struct) -> Result<#class_name, Self::Error> {
let is_kind_of : bool = unsafe { msg_send!(parent, isKindOfClass:class!(#class_name))};
if is_kind_of {
Ok(#class_name(parent.0))
} else {
Err(#error_msg)
}
}
}
};
result.push(try_into_block);
}
}
}
if !self.is_protocol() {
let impl_block = if self.is_template() {
let template_names: Vec<Ident> = self
.template_names
.iter()
.map(|g| ctx.rust_ident(g))
.collect();
quote! {
impl <#(#template_names :'static),*> #trait_name <#(#template_names),*> for #class_name {
}
}
} else {
quote! {
impl #trait_name for #class_name {
}
}
};
result.push(impl_block);
}
result.push(trait_block);
result.saw_objc();
}
}
pub(crate) fn codegen(
context: BindgenContext,
) -> (Vec<proc_macro2::TokenStream>, BindgenOptions) {
context.gen(|context| {
let _t = context.timer("codegen");
let counter = Cell::new(0);
let mut result = CodegenResult::new(&counter);
debug!("codegen: {:?}", context.options());
if context.options().emit_ir {
let codegen_items = context.codegen_items();
for (id, item) in context.items() {
if codegen_items.contains(&id) {
println!("ir: {:?} = {:#?}", id, item);
}
}
}
if let Some(path) = context.options().emit_ir_graphviz.as_ref() {
match dot::write_dot_file(context, path) {
Ok(()) => info!(
"Your dot file was generated successfully into: {}",
path
),
Err(e) => warn!("{}", e),
}
}
if let Some(spec) = context.options().depfile.as_ref() {
match spec.write(context.deps()) {
Ok(()) => info!(
"Your depfile was generated successfully into: {}",
spec.depfile_path.display()
),
Err(e) => warn!("{}", e),
}
}
context.resolve_item(context.root_module()).codegen(
context,
&mut result,
&(),
);
if let Some(ref lib_name) = context.options().dynamic_library_name {
let lib_ident = context.rust_ident(lib_name);
let dynamic_items_tokens =
result.dynamic_items().get_tokens(lib_ident);
result.push(dynamic_items_tokens);
}
result.items
})
}
pub mod utils {
use super::{error, ToRustTyOrOpaque};
use crate::ir::context::BindgenContext;
use crate::ir::function::{Abi, FunctionSig};
use crate::ir::item::{Item, ItemCanonicalPath};
use crate::ir::ty::TypeKind;
use proc_macro2;
use std::borrow::Cow;
use std::mem;
use std::str::FromStr;
pub fn prepend_bitfield_unit_type(
ctx: &BindgenContext,
result: &mut Vec<proc_macro2::TokenStream>,
) {
let bitfield_unit_src = include_str!("./bitfield_unit.rs");
let bitfield_unit_src = if ctx.options().rust_features().min_const_fn {
Cow::Borrowed(bitfield_unit_src)
} else {
Cow::Owned(bitfield_unit_src.replace("const fn ", "fn "))
};
let bitfield_unit_type =
proc_macro2::TokenStream::from_str(&bitfield_unit_src).unwrap();
let bitfield_unit_type = quote!(#bitfield_unit_type);
let items = vec![bitfield_unit_type];
let old_items = mem::replace(result, items);
result.extend(old_items);
}
pub fn prepend_objc_header(
ctx: &BindgenContext,
result: &mut Vec<proc_macro2::TokenStream>,
) {
let use_objc = if ctx.options().objc_extern_crate {
quote! {
#[macro_use]
extern crate objc;
}
} else {
quote! {
use objc;
}
};
let id_type = quote! {
#[allow(non_camel_case_types)]
pub type id = *mut objc::runtime::Object;
};
let items = vec![use_objc, id_type];
let old_items = mem::replace(result, items);
result.extend(old_items.into_iter());
}
pub fn prepend_block_header(
ctx: &BindgenContext,
result: &mut Vec<proc_macro2::TokenStream>,
) {
let use_block = if ctx.options().block_extern_crate {
quote! {
extern crate block;
}
} else {
quote! {
use block;
}
};
let items = vec![use_block];
let old_items = mem::replace(result, items);
result.extend(old_items.into_iter());
}
pub fn prepend_union_types(
ctx: &BindgenContext,
result: &mut Vec<proc_macro2::TokenStream>,
) {
let prefix = ctx.trait_prefix();
// If the target supports `const fn`, declare eligible functions
// as `const fn` else just `fn`.
let const_fn = if ctx.options().rust_features().min_const_fn {
quote! { const fn }
} else {
quote! { fn }
};
// TODO(emilio): The fmt::Debug impl could be way nicer with
// std::intrinsics::type_name, but...
let union_field_decl = quote! {
#[repr(C)]
pub struct __BindgenUnionField<T>(::#prefix::marker::PhantomData<T>);
};
let union_field_impl = quote! {
impl<T> __BindgenUnionField<T> {
#[inline]
pub #const_fn new() -> Self {
__BindgenUnionField(::#prefix::marker::PhantomData)
}
#[inline]
pub unsafe fn as_ref(&self) -> &T {
::#prefix::mem::transmute(self)
}
#[inline]
pub unsafe fn as_mut(&mut self) -> &mut T {
::#prefix::mem::transmute(self)
}
}
};
let union_field_default_impl = quote! {
impl<T> ::#prefix::default::Default for __BindgenUnionField<T> {
#[inline]
fn default() -> Self {
Self::new()
}
}
};
let union_field_clone_impl = quote! {
impl<T> ::#prefix::clone::Clone for __BindgenUnionField<T> {
#[inline]
fn clone(&self) -> Self {
Self::new()
}
}
};
let union_field_copy_impl = quote! {
impl<T> ::#prefix::marker::Copy for __BindgenUnionField<T> {}
};
let union_field_debug_impl = quote! {
impl<T> ::#prefix::fmt::Debug for __BindgenUnionField<T> {
fn fmt(&self, fmt: &mut ::#prefix::fmt::Formatter<'_>)
-> ::#prefix::fmt::Result {
fmt.write_str("__BindgenUnionField")
}
}
};
// The actual memory of the filed will be hashed, so that's why these
// field doesn't do anything with the hash.
let union_field_hash_impl = quote! {
impl<T> ::#prefix::hash::Hash for __BindgenUnionField<T> {
fn hash<H: ::#prefix::hash::Hasher>(&self, _state: &mut H) {
}
}
};
let union_field_partialeq_impl = quote! {
impl<T> ::#prefix::cmp::PartialEq for __BindgenUnionField<T> {
fn eq(&self, _other: &__BindgenUnionField<T>) -> bool {
true
}
}
};
let union_field_eq_impl = quote! {
impl<T> ::#prefix::cmp::Eq for __BindgenUnionField<T> {
}
};
let items = vec![
union_field_decl,
union_field_impl,
union_field_default_impl,
union_field_clone_impl,
union_field_copy_impl,
union_field_debug_impl,
union_field_hash_impl,
union_field_partialeq_impl,
union_field_eq_impl,
];
let old_items = mem::replace(result, items);
result.extend(old_items.into_iter());
}
pub fn prepend_incomplete_array_types(
ctx: &BindgenContext,
result: &mut Vec<proc_macro2::TokenStream>,
) {
let prefix = ctx.trait_prefix();
// If the target supports `const fn`, declare eligible functions
// as `const fn` else just `fn`.
let const_fn = if ctx.options().rust_features().min_const_fn {
quote! { const fn }
} else {
quote! { fn }
};
let incomplete_array_decl = quote! {
#[repr(C)]
#[derive(Default)]
pub struct __IncompleteArrayField<T>(
::#prefix::marker::PhantomData<T>, [T; 0]);
};
let incomplete_array_impl = quote! {
impl<T> __IncompleteArrayField<T> {
#[inline]
pub #const_fn new() -> Self {
__IncompleteArrayField(::#prefix::marker::PhantomData, [])
}
#[inline]
pub fn as_ptr(&self) -> *const T {
self as *const _ as *const T
}
#[inline]
pub fn as_mut_ptr(&mut self) -> *mut T {
self as *mut _ as *mut T
}
#[inline]
pub unsafe fn as_slice(&self, len: usize) -> &[T] {
::#prefix::slice::from_raw_parts(self.as_ptr(), len)
}
#[inline]
pub unsafe fn as_mut_slice(&mut self, len: usize) -> &mut [T] {
::#prefix::slice::from_raw_parts_mut(self.as_mut_ptr(), len)
}
}
};
let incomplete_array_debug_impl = quote! {
impl<T> ::#prefix::fmt::Debug for __IncompleteArrayField<T> {
fn fmt(&self, fmt: &mut ::#prefix::fmt::Formatter<'_>)
-> ::#prefix::fmt::Result {
fmt.write_str("__IncompleteArrayField")
}
}
};
let items = vec![
incomplete_array_decl,
incomplete_array_impl,
incomplete_array_debug_impl,
];
let old_items = mem::replace(result, items);
result.extend(old_items.into_iter());
}
pub fn prepend_complex_type(result: &mut Vec<proc_macro2::TokenStream>) {
let complex_type = quote! {
#[derive(PartialEq, Copy, Clone, Hash, Debug, Default)]
#[repr(C)]
pub struct __BindgenComplex<T> {
pub re: T,
pub im: T
}
};
let items = vec![complex_type];
let old_items = mem::replace(result, items);
result.extend(old_items.into_iter());
}
pub fn build_path(
item: &Item,
ctx: &BindgenContext,
) -> error::Result<proc_macro2::TokenStream> {
let path = item.namespace_aware_canonical_path(ctx);
let tokens =
proc_macro2::TokenStream::from_str(&path.join("::")).unwrap();
Ok(tokens)
}
fn primitive_ty(
ctx: &BindgenContext,
name: &str,
) -> proc_macro2::TokenStream {
let ident = ctx.rust_ident_raw(name);
quote! {
#ident
}
}
pub fn type_from_named(
ctx: &BindgenContext,
name: &str,
) -> Option<proc_macro2::TokenStream> {
// FIXME: We could use the inner item to check this is really a
// primitive type but, who the heck overrides these anyway?
Some(match name {
"int8_t" => primitive_ty(ctx, "i8"),
"uint8_t" => primitive_ty(ctx, "u8"),
"int16_t" => primitive_ty(ctx, "i16"),
"uint16_t" => primitive_ty(ctx, "u16"),
"int32_t" => primitive_ty(ctx, "i32"),
"uint32_t" => primitive_ty(ctx, "u32"),
"int64_t" => primitive_ty(ctx, "i64"),
"uint64_t" => primitive_ty(ctx, "u64"),
"size_t" if ctx.options().size_t_is_usize => {
primitive_ty(ctx, "usize")
}
"uintptr_t" => primitive_ty(ctx, "usize"),
"ssize_t" if ctx.options().size_t_is_usize => {
primitive_ty(ctx, "isize")
}
"intptr_t" | "ptrdiff_t" => primitive_ty(ctx, "isize"),
_ => return None,
})
}
pub fn fnsig_return_ty(
ctx: &BindgenContext,
sig: &FunctionSig,
) -> proc_macro2::TokenStream {
let return_item = ctx.resolve_item(sig.return_type());
if let TypeKind::Void = *return_item.kind().expect_type().kind() {
quote! {}
} else {
let ret_ty = return_item.to_rust_ty_or_opaque(ctx, &());
quote! {
-> #ret_ty
}
}
}
pub fn fnsig_arguments(
ctx: &BindgenContext,
sig: &FunctionSig,
) -> Vec<proc_macro2::TokenStream> {
use super::ToPtr;
let mut unnamed_arguments = 0;
let mut args = sig
.argument_types()
.iter()
.map(|&(ref name, ty)| {
let arg_item = ctx.resolve_item(ty);
let arg_ty = arg_item.kind().expect_type();
// From the C90 standard[1]:
//
// A declaration of a parameter as "array of type" shall be
// adjusted to "qualified pointer to type", where the type
// qualifiers (if any) are those specified within the [ and ] of
// the array type derivation.
//
// [1]: http://c0x.coding-guidelines.com/6.7.5.3.html
let arg_ty = match *arg_ty.canonical_type(ctx).kind() {
TypeKind::Array(t, _) => {
let stream =
if ctx.options().array_pointers_in_arguments {
arg_ty.to_rust_ty_or_opaque(ctx, &arg_item)
} else {
t.to_rust_ty_or_opaque(ctx, &())
};
stream.to_ptr(ctx.resolve_type(t).is_const())
}
TypeKind::Pointer(inner) => {
let inner = ctx.resolve_item(inner);
let inner_ty = inner.expect_type();
if let TypeKind::ObjCInterface(ref interface) =
*inner_ty.canonical_type(ctx).kind()
{
let name = ctx.rust_ident(interface.name());
quote! {
#name
}
} else {
arg_item.to_rust_ty_or_opaque(ctx, &())
}
}
_ => arg_item.to_rust_ty_or_opaque(ctx, &()),
};
let arg_name = match *name {
Some(ref name) => ctx.rust_mangle(name).into_owned(),
None => {
unnamed_arguments += 1;
format!("arg{}", unnamed_arguments)
}
};
assert!(!arg_name.is_empty());
let arg_name = ctx.rust_ident(arg_name);
quote! {
#arg_name : #arg_ty
}
})
.collect::<Vec<_>>();
if sig.is_variadic() {
args.push(quote! { ... })
}
args
}
pub fn fnsig_argument_identifiers(
ctx: &BindgenContext,
sig: &FunctionSig,
) -> Vec<proc_macro2::TokenStream> {
let mut unnamed_arguments = 0;
let args = sig
.argument_types()
.iter()
.map(|&(ref name, _ty)| {
let arg_name = match *name {
Some(ref name) => ctx.rust_mangle(name).into_owned(),
None => {
unnamed_arguments += 1;
format!("arg{}", unnamed_arguments)
}
};
assert!(!arg_name.is_empty());
let arg_name = ctx.rust_ident(arg_name);
quote! {
#arg_name
}
})
.collect::<Vec<_>>();
args
}
pub fn fnsig_block(
ctx: &BindgenContext,
sig: &FunctionSig,
) -> proc_macro2::TokenStream {
let args = sig.argument_types().iter().map(|&(_, ty)| {
let arg_item = ctx.resolve_item(ty);
arg_item.to_rust_ty_or_opaque(ctx, &())
});
let return_item = ctx.resolve_item(sig.return_type());
let ret_ty =
if let TypeKind::Void = *return_item.kind().expect_type().kind() {
quote! { () }
} else {
return_item.to_rust_ty_or_opaque(ctx, &())
};
quote! {
*const ::block::Block<(#(#args,)*), #ret_ty>
}
}
// Returns true if `canonical_name` will end up as `mangled_name` at the
// machine code level, i.e. after LLVM has applied any target specific
// mangling.
pub fn names_will_be_identical_after_mangling(
canonical_name: &str,
mangled_name: &str,
call_conv: Option<Abi>,
) -> bool {
// If the mangled name and the canonical name are the same then no
// mangling can have happened between the two versions.
if canonical_name == mangled_name {
return true;
}
// Working with &[u8] makes indexing simpler than with &str
let canonical_name = canonical_name.as_bytes();
let mangled_name = mangled_name.as_bytes();
let (mangling_prefix, expect_suffix) = match call_conv {
Some(Abi::C) |
// None is the case for global variables
None => {
(b'_', false)
}
Some(Abi::Stdcall) => (b'_', true),
Some(Abi::Fastcall) => (b'@', true),
// This is something we don't recognize, stay on the safe side
// by emitting the `#[link_name]` attribute
Some(_) => return false,
};
// Check that the mangled name is long enough to at least contain the
// canonical name plus the expected prefix.
if mangled_name.len() < canonical_name.len() + 1 {
return false;
}
// Return if the mangled name does not start with the prefix expected
// for the given calling convention.
if mangled_name[0] != mangling_prefix {
return false;
}
// Check that the mangled name contains the canonical name after the
// prefix
if &mangled_name[1..canonical_name.len() + 1] != canonical_name {
return false;
}
// If the given calling convention also prescribes a suffix, check that
// it exists too
if expect_suffix {
let suffix = &mangled_name[canonical_name.len() + 1..];
// The shortest suffix is "@0"
if suffix.len() < 2 {
return false;
}
// Check that the suffix starts with '@' and is all ASCII decimals
// after that.
if suffix[0] != b'@' || !suffix[1..].iter().all(u8::is_ascii_digit)
{
return false;
}
} else if mangled_name.len() != canonical_name.len() + 1 {
// If we don't expect a prefix but there is one, we need the
// #[link_name] attribute
return false;
}
true
}
}