diff options
Diffstat (limited to 'third_party/rust/bindgen/codegen/helpers.rs')
| -rw-r--r-- | third_party/rust/bindgen/codegen/helpers.rs | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/third_party/rust/bindgen/codegen/helpers.rs b/third_party/rust/bindgen/codegen/helpers.rs new file mode 100644 index 0000000000..48bfe56dde --- /dev/null +++ b/third_party/rust/bindgen/codegen/helpers.rs @@ -0,0 +1,355 @@ +//! Helpers for code generation that don't need macro expansion. + +use crate::ir::context::BindgenContext; +use crate::ir::layout::Layout; + +pub(crate) mod attributes { + use proc_macro2::{Ident, Span, TokenStream}; + use std::{borrow::Cow, str::FromStr}; + + pub(crate) fn repr(which: &str) -> TokenStream { + let which = Ident::new(which, Span::call_site()); + quote! { + #[repr( #which )] + } + } + + pub(crate) fn repr_list(which_ones: &[&str]) -> TokenStream { + let which_ones = which_ones + .iter() + .cloned() + .map(|one| TokenStream::from_str(one).expect("repr to be valid")); + quote! { + #[repr( #( #which_ones ),* )] + } + } + + pub(crate) fn derives(which_ones: &[&str]) -> TokenStream { + let which_ones = which_ones + .iter() + .cloned() + .map(|one| TokenStream::from_str(one).expect("derive to be valid")); + quote! { + #[derive( #( #which_ones ),* )] + } + } + + pub(crate) fn inline() -> TokenStream { + quote! { + #[inline] + } + } + + pub(crate) fn must_use() -> TokenStream { + quote! { + #[must_use] + } + } + + pub(crate) fn non_exhaustive() -> TokenStream { + quote! { + #[non_exhaustive] + } + } + + pub(crate) fn doc(comment: String) -> TokenStream { + if comment.is_empty() { + quote!() + } else { + quote!(#[doc = #comment]) + } + } + + pub(crate) fn link_name<const MANGLE: bool>(name: &str) -> TokenStream { + // LLVM mangles the name by default but it's already mangled. + // Prefixing the name with \u{1} should tell LLVM to not mangle it. + let name: Cow<'_, str> = if MANGLE { + name.into() + } else { + format!("\u{1}{}", name).into() + }; + + quote! { + #[link_name = #name] + } + } +} + +/// Generates a proper type for a field or type with a given `Layout`, that is, +/// a type with the correct size and alignment restrictions. +pub(crate) fn blob(ctx: &BindgenContext, layout: Layout) -> syn::Type { + let opaque = layout.opaque(); + + // FIXME(emilio, #412): We fall back to byte alignment, but there are + // some things that legitimately are more than 8-byte aligned. + // + // Eventually we should be able to `unwrap` here, but... + let ty = match opaque.known_rust_type_for_array(ctx) { + Some(ty) => ty, + None => { + warn!("Found unknown alignment on code generation!"); + syn::parse_quote! { u8 } + } + }; + + let data_len = opaque.array_size(ctx).unwrap_or(layout.size); + + if data_len == 1 { + ty + } else { + syn::parse_quote! { [ #ty ; #data_len ] } + } +} + +/// Integer type of the same size as the given `Layout`. +pub(crate) fn integer_type( + ctx: &BindgenContext, + layout: Layout, +) -> Option<syn::Type> { + Layout::known_type_for_size(ctx, layout.size) +} + +/// Generates a bitfield allocation unit type for a type with the given `Layout`. +pub(crate) fn bitfield_unit(ctx: &BindgenContext, layout: Layout) -> syn::Type { + let size = layout.size; + let ty = syn::parse_quote! { __BindgenBitfieldUnit<[u8; #size]> }; + + if ctx.options().enable_cxx_namespaces { + return syn::parse_quote! { root::#ty }; + } + + ty +} + +pub(crate) mod ast_ty { + use crate::ir::context::BindgenContext; + use crate::ir::function::FunctionSig; + use crate::ir::layout::Layout; + use crate::ir::ty::{FloatKind, IntKind}; + use proc_macro2::{self, TokenStream}; + use std::str::FromStr; + + pub(crate) fn c_void(ctx: &BindgenContext) -> syn::Type { + // ctypes_prefix takes precedence + match ctx.options().ctypes_prefix { + Some(ref prefix) => { + let prefix = TokenStream::from_str(prefix.as_str()).unwrap(); + syn::parse_quote! { #prefix::c_void } + } + None => { + if ctx.options().use_core && + ctx.options().rust_features.core_ffi_c_void + { + syn::parse_quote! { ::core::ffi::c_void } + } else { + syn::parse_quote! { ::std::os::raw::c_void } + } + } + } + } + + pub(crate) fn raw_type(ctx: &BindgenContext, name: &str) -> syn::Type { + let ident = ctx.rust_ident_raw(name); + match ctx.options().ctypes_prefix { + Some(ref prefix) => { + let prefix = TokenStream::from_str(prefix.as_str()).unwrap(); + syn::parse_quote! { #prefix::#ident } + } + None => { + if ctx.options().use_core && + ctx.options().rust_features().core_ffi_c + { + syn::parse_quote! { ::core::ffi::#ident } + } else { + syn::parse_quote! { ::std::os::raw::#ident } + } + } + } + } + + pub(crate) fn int_kind_rust_type( + ctx: &BindgenContext, + ik: IntKind, + layout: Option<Layout>, + ) -> syn::Type { + match ik { + IntKind::Bool => syn::parse_quote! { bool }, + IntKind::Char { .. } => raw_type(ctx, "c_char"), + IntKind::SChar => raw_type(ctx, "c_schar"), + IntKind::UChar => raw_type(ctx, "c_uchar"), + IntKind::Short => raw_type(ctx, "c_short"), + IntKind::UShort => raw_type(ctx, "c_ushort"), + IntKind::Int => raw_type(ctx, "c_int"), + IntKind::UInt => raw_type(ctx, "c_uint"), + IntKind::Long => raw_type(ctx, "c_long"), + IntKind::ULong => raw_type(ctx, "c_ulong"), + IntKind::LongLong => raw_type(ctx, "c_longlong"), + IntKind::ULongLong => raw_type(ctx, "c_ulonglong"), + IntKind::WChar => { + let layout = + layout.expect("Couldn't compute wchar_t's layout?"); + Layout::known_type_for_size(ctx, layout.size) + .expect("Non-representable wchar_t?") + } + + IntKind::I8 => syn::parse_quote! { i8 }, + IntKind::U8 => syn::parse_quote! { u8 }, + IntKind::I16 => syn::parse_quote! { i16 }, + IntKind::U16 => syn::parse_quote! { u16 }, + IntKind::I32 => syn::parse_quote! { i32 }, + IntKind::U32 => syn::parse_quote! { u32 }, + IntKind::I64 => syn::parse_quote! { i64 }, + IntKind::U64 => syn::parse_quote! { u64 }, + IntKind::Custom { name, .. } => { + syn::parse_str(name).expect("Invalid integer type.") + } + IntKind::U128 => { + if ctx.options().rust_features.i128_and_u128 { + syn::parse_quote! { u128 } + } else { + // Best effort thing, but wrong alignment + // unfortunately. + syn::parse_quote! { [u64; 2] } + } + } + IntKind::I128 => { + if ctx.options().rust_features.i128_and_u128 { + syn::parse_quote! { i128 } + } else { + syn::parse_quote! { [u64; 2] } + } + } + } + } + + pub(crate) fn float_kind_rust_type( + ctx: &BindgenContext, + fk: FloatKind, + layout: Option<Layout>, + ) -> syn::Type { + // TODO: we probably should take the type layout into account more + // often? + // + // Also, maybe this one shouldn't be the default? + match (fk, ctx.options().convert_floats) { + (FloatKind::Float16, _) => { + // TODO: do f16 when rust lands it + ctx.generated_bindgen_float16(); + if ctx.options().enable_cxx_namespaces { + syn::parse_quote! { root::__BindgenFloat16 } + } else { + syn::parse_quote! { __BindgenFloat16 } + } + } + (FloatKind::Float, true) => syn::parse_quote! { f32 }, + (FloatKind::Double, true) => syn::parse_quote! { f64 }, + (FloatKind::Float, false) => raw_type(ctx, "c_float"), + (FloatKind::Double, false) => raw_type(ctx, "c_double"), + (FloatKind::LongDouble, _) => { + match layout { + Some(layout) => { + match layout.size { + 4 => syn::parse_quote! { f32 }, + 8 => syn::parse_quote! { f64 }, + // TODO(emilio): If rust ever gains f128 we should + // use it here and below. + _ => super::integer_type(ctx, layout) + .unwrap_or(syn::parse_quote! { f64 }), + } + } + None => { + debug_assert!( + false, + "How didn't we know the layout for a primitive type?" + ); + syn::parse_quote! { f64 } + } + } + } + (FloatKind::Float128, _) => { + if ctx.options().rust_features.i128_and_u128 { + syn::parse_quote! { u128 } + } else { + syn::parse_quote! { [u64; 2] } + } + } + } + } + + pub(crate) fn int_expr(val: i64) -> TokenStream { + // Don't use quote! { #val } because that adds the type suffix. + let val = proc_macro2::Literal::i64_unsuffixed(val); + quote!(#val) + } + + pub(crate) fn uint_expr(val: u64) -> TokenStream { + // Don't use quote! { #val } because that adds the type suffix. + let val = proc_macro2::Literal::u64_unsuffixed(val); + quote!(#val) + } + + pub(crate) fn cstr_expr(mut string: String) -> TokenStream { + string.push('\0'); + let b = proc_macro2::Literal::byte_string(string.as_bytes()); + quote! { + #b + } + } + + pub(crate) fn float_expr( + ctx: &BindgenContext, + f: f64, + ) -> Result<TokenStream, ()> { + if f.is_finite() { + let val = proc_macro2::Literal::f64_unsuffixed(f); + + return Ok(quote!(#val)); + } + + let prefix = ctx.trait_prefix(); + + if f.is_nan() { + return Ok(quote! { + ::#prefix::f64::NAN + }); + } + + if f.is_infinite() { + return Ok(if f.is_sign_positive() { + quote! { + ::#prefix::f64::INFINITY + } + } else { + quote! { + ::#prefix::f64::NEG_INFINITY + } + }); + } + + warn!("Unknown non-finite float number: {:?}", f); + Err(()) + } + + pub(crate) fn arguments_from_signature( + signature: &FunctionSig, + ctx: &BindgenContext, + ) -> Vec<TokenStream> { + let mut unnamed_arguments = 0; + signature + .argument_types() + .iter() + .map(|&(ref name, _ty)| match *name { + Some(ref name) => { + let name = ctx.rust_ident(name); + quote! { #name } + } + None => { + unnamed_arguments += 1; + let name = + ctx.rust_ident(format!("arg{}", unnamed_arguments)); + quote! { #name } + } + }) + .collect() + } +} |