| use crate::syntax::atom::Atom::{self, *}; |
| use crate::syntax::namespace::Namespace; |
| use crate::syntax::{ |
| error, ident, Api, Enum, ExternFn, ExternType, Lang, Receiver, Ref, Slice, Struct, Ty1, Type, |
| Types, |
| }; |
| use proc_macro2::{Delimiter, Group, Ident, TokenStream}; |
| use quote::{quote, ToTokens}; |
| use std::collections::HashSet; |
| use std::fmt::Display; |
| use syn::{Error, Result}; |
| |
| struct Check<'a> { |
| namespace: &'a Namespace, |
| apis: &'a [Api], |
| types: &'a Types<'a>, |
| errors: &'a mut Vec<Error>, |
| } |
| |
| pub(crate) fn typecheck(namespace: &Namespace, apis: &[Api], types: &Types) -> Result<()> { |
| let mut errors = Vec::new(); |
| let mut cx = Check { |
| namespace, |
| apis, |
| types, |
| errors: &mut errors, |
| }; |
| do_typecheck(&mut cx); |
| combine_errors(errors) |
| } |
| |
| fn do_typecheck(cx: &mut Check) { |
| for segment in cx.namespace { |
| cx.errors.extend(ident::check(segment).err()); |
| } |
| |
| for ty in cx.types { |
| match ty { |
| Type::Ident(ident) => check_type_ident(cx, ident), |
| Type::RustBox(ptr) => check_type_box(cx, ptr), |
| Type::RustVec(ty) => check_type_rust_vec(cx, ty), |
| Type::UniquePtr(ptr) => check_type_unique_ptr(cx, ptr), |
| Type::CxxVector(ptr) => check_type_cxx_vector(cx, ptr), |
| Type::Ref(ty) => check_type_ref(cx, ty), |
| Type::Slice(ty) => check_type_slice(cx, ty), |
| _ => {} |
| } |
| } |
| |
| for api in cx.apis { |
| match api { |
| Api::Struct(strct) => check_api_struct(cx, strct), |
| Api::Enum(enm) => check_api_enum(cx, enm), |
| Api::CxxType(ty) | Api::RustType(ty) => check_api_type(cx, ty), |
| Api::CxxFunction(efn) | Api::RustFunction(efn) => check_api_fn(cx, efn), |
| _ => {} |
| } |
| } |
| |
| for api in cx.apis { |
| if let Api::CxxFunction(efn) = api { |
| check_mut_return_restriction(cx, efn); |
| } |
| if let Api::CxxFunction(efn) | Api::RustFunction(efn) = api { |
| check_multiple_arg_lifetimes(cx, efn); |
| } |
| } |
| |
| ident::check_all(cx.apis, cx.errors); |
| } |
| |
| impl Check<'_> { |
| fn error(&mut self, sp: impl ToTokens, msg: impl Display) { |
| self.errors.push(Error::new_spanned(sp, msg)); |
| } |
| } |
| |
| fn check_type_ident(cx: &mut Check, ident: &Ident) { |
| if Atom::from(ident).is_none() |
| && !cx.types.structs.contains_key(ident) |
| && !cx.types.enums.contains_key(ident) |
| && !cx.types.cxx.contains(ident) |
| && !cx.types.rust.contains(ident) |
| { |
| cx.error(ident, "unsupported type"); |
| } |
| } |
| |
| fn check_type_box(cx: &mut Check, ptr: &Ty1) { |
| if let Type::Ident(ident) = &ptr.inner { |
| if cx.types.cxx.contains(ident) { |
| cx.error(ptr, error::BOX_CXX_TYPE.msg); |
| } |
| |
| if Atom::from(ident).is_none() { |
| return; |
| } |
| } |
| |
| cx.error(ptr, "unsupported target type of Box"); |
| } |
| |
| fn check_type_rust_vec(cx: &mut Check, ty: &Ty1) { |
| if let Type::Ident(ident) = &ty.inner { |
| if cx.types.cxx.contains(ident) { |
| cx.error(ty, "Rust Vec containing C++ type is not supported yet"); |
| return; |
| } |
| |
| match Atom::from(ident) { |
| None | Some(U8) | Some(U16) | Some(U32) | Some(U64) | Some(Usize) | Some(I8) |
| | Some(I16) | Some(I32) | Some(I64) | Some(Isize) | Some(F32) | Some(F64) => return, |
| Some(Bool) | Some(RustString) => { /* todo */ } |
| Some(CxxString) => {} |
| } |
| } |
| |
| cx.error(ty, "unsupported element type of Vec"); |
| } |
| |
| fn check_type_unique_ptr(cx: &mut Check, ptr: &Ty1) { |
| if let Type::Ident(ident) = &ptr.inner { |
| if cx.types.rust.contains(ident) { |
| cx.error(ptr, "unique_ptr of a Rust type is not supported yet"); |
| } |
| |
| match Atom::from(ident) { |
| None | Some(CxxString) => return, |
| _ => {} |
| } |
| } else if let Type::CxxVector(_) = &ptr.inner { |
| return; |
| } |
| |
| cx.error(ptr, "unsupported unique_ptr target type"); |
| } |
| |
| fn check_type_cxx_vector(cx: &mut Check, ptr: &Ty1) { |
| if let Type::Ident(ident) = &ptr.inner { |
| if cx.types.rust.contains(ident) { |
| cx.error( |
| ptr, |
| "C++ vector containing a Rust type is not supported yet", |
| ); |
| } |
| |
| match Atom::from(ident) { |
| None | Some(U8) | Some(U16) | Some(U32) | Some(U64) | Some(Usize) | Some(I8) |
| | Some(I16) | Some(I32) | Some(I64) | Some(Isize) | Some(F32) | Some(F64) => return, |
| Some(CxxString) => { /* todo */ } |
| Some(Bool) | Some(RustString) => {} |
| } |
| } |
| |
| cx.error(ptr, "unsupported vector target type"); |
| } |
| |
| fn check_type_ref(cx: &mut Check, ty: &Ref) { |
| if ty.lifetime.is_some() { |
| cx.error(ty, "references with explicit lifetimes are not supported"); |
| } |
| |
| match ty.inner { |
| Type::Fn(_) | Type::Void(_) => {} |
| Type::Ref(_) => { |
| cx.error(ty, "C++ does not allow references to references"); |
| return; |
| } |
| _ => return, |
| } |
| |
| cx.error(ty, "unsupported reference type"); |
| } |
| |
| fn check_type_slice(cx: &mut Check, ty: &Slice) { |
| cx.error(ty, "only &[u8] is supported so far, not other slice types"); |
| } |
| |
| fn check_api_struct(cx: &mut Check, strct: &Struct) { |
| check_reserved_name(cx, &strct.ident); |
| |
| if strct.fields.is_empty() { |
| let span = span_for_struct_error(strct); |
| cx.error(span, "structs without any fields are not supported"); |
| } |
| |
| for field in &strct.fields { |
| if is_unsized(cx, &field.ty) { |
| let desc = describe(cx, &field.ty); |
| let msg = format!("using {} by value is not supported", desc); |
| cx.error(field, msg); |
| } |
| if let Type::Fn(_) = field.ty { |
| cx.error( |
| field, |
| "function pointers in a struct field are not implemented yet", |
| ); |
| } |
| } |
| } |
| |
| fn check_api_enum(cx: &mut Check, enm: &Enum) { |
| check_reserved_name(cx, &enm.ident); |
| |
| if enm.variants.is_empty() { |
| let span = span_for_enum_error(enm); |
| cx.error(span, "enums without any variants are not supported"); |
| } |
| |
| let mut discriminants = HashSet::new(); |
| enm.variants.iter().fold(0, |next_discriminant, variant| { |
| let discriminant = variant.discriminant.unwrap_or(next_discriminant); |
| if !discriminants.insert(discriminant) { |
| let msg = format!("discriminant value `{}` already exists", discriminant); |
| cx.error(span_for_enum_error(enm), msg); |
| } |
| discriminant + 1 |
| }); |
| } |
| |
| fn check_api_type(cx: &mut Check, ty: &ExternType) { |
| check_reserved_name(cx, &ty.ident); |
| } |
| |
| fn check_api_fn(cx: &mut Check, efn: &ExternFn) { |
| if let Some(receiver) = &efn.receiver { |
| let ref span = span_for_receiver_error(receiver); |
| |
| if receiver.ty == "Self" { |
| let mutability = match receiver.mutability { |
| Some(_) => "mut ", |
| None => "", |
| }; |
| let msg = format!( |
| "unnamed receiver type is only allowed if the surrounding \ |
| extern block contains exactly one extern type; \ |
| use `self: &{mutability}TheType`", |
| mutability = mutability, |
| ); |
| cx.error(span, msg); |
| } else if !cx.types.structs.contains_key(&receiver.ty) |
| && !cx.types.cxx.contains(&receiver.ty) |
| && !cx.types.rust.contains(&receiver.ty) |
| { |
| cx.error(span, "unrecognized receiver type"); |
| } |
| |
| if receiver.lifetime.is_some() { |
| cx.error(span, "references with explicit lifetimes are not supported"); |
| } |
| } |
| |
| for arg in &efn.args { |
| if is_unsized(cx, &arg.ty) { |
| let desc = describe(cx, &arg.ty); |
| let msg = format!("passing {} by value is not supported", desc); |
| cx.error(arg, msg); |
| } |
| if let Type::Fn(_) = arg.ty { |
| if efn.lang == Lang::Rust { |
| cx.error( |
| arg, |
| "passing a function pointer from C++ to Rust is not implemented yet", |
| ); |
| } |
| } |
| } |
| |
| if let Some(ty) = &efn.ret { |
| if is_unsized(cx, ty) { |
| let desc = describe(cx, ty); |
| let msg = format!("returning {} by value is not supported", desc); |
| cx.error(ty, msg); |
| } |
| if let Type::Fn(_) = ty { |
| cx.error(ty, "returning a function pointer is not implemented yet"); |
| } |
| } |
| } |
| |
| fn check_mut_return_restriction(cx: &mut Check, efn: &ExternFn) { |
| match &efn.ret { |
| Some(Type::Ref(ty)) if ty.mutability.is_some() => {} |
| _ => return, |
| } |
| |
| for arg in &efn.args { |
| if let Type::Ref(ty) = &arg.ty { |
| if ty.mutability.is_some() { |
| return; |
| } |
| } |
| } |
| |
| cx.error( |
| efn, |
| "&mut return type is not allowed unless there is a &mut argument", |
| ); |
| } |
| |
| fn check_multiple_arg_lifetimes(cx: &mut Check, efn: &ExternFn) { |
| match &efn.ret { |
| Some(Type::Ref(_)) => {} |
| _ => return, |
| } |
| |
| let mut reference_args = 0; |
| for arg in &efn.args { |
| if let Type::Ref(_) = &arg.ty { |
| reference_args += 1; |
| } |
| } |
| |
| if efn.receiver.is_some() { |
| reference_args += 1; |
| } |
| |
| if reference_args != 1 { |
| cx.error( |
| efn, |
| "functions that return a reference must take exactly one input reference", |
| ); |
| } |
| } |
| |
| fn check_reserved_name(cx: &mut Check, ident: &Ident) { |
| if ident == "Box" |
| || ident == "UniquePtr" |
| || ident == "Vec" |
| || ident == "CxxVector" |
| || Atom::from(ident).is_some() |
| { |
| cx.error(ident, "reserved name"); |
| } |
| } |
| |
| fn is_unsized(cx: &mut Check, ty: &Type) -> bool { |
| let ident = match ty { |
| Type::Ident(ident) => ident, |
| Type::CxxVector(_) | Type::Slice(_) | Type::Void(_) => return true, |
| _ => return false, |
| }; |
| ident == CxxString || cx.types.cxx.contains(ident) || cx.types.rust.contains(ident) |
| } |
| |
| fn span_for_struct_error(strct: &Struct) -> TokenStream { |
| let struct_token = strct.struct_token; |
| let mut brace_token = Group::new(Delimiter::Brace, TokenStream::new()); |
| brace_token.set_span(strct.brace_token.span); |
| quote!(#struct_token #brace_token) |
| } |
| |
| fn span_for_enum_error(enm: &Enum) -> TokenStream { |
| let enum_token = enm.enum_token; |
| let mut brace_token = Group::new(Delimiter::Brace, TokenStream::new()); |
| brace_token.set_span(enm.brace_token.span); |
| quote!(#enum_token #brace_token) |
| } |
| |
| fn span_for_receiver_error(receiver: &Receiver) -> TokenStream { |
| let ampersand = receiver.ampersand; |
| let lifetime = &receiver.lifetime; |
| let mutability = receiver.mutability; |
| if receiver.shorthand { |
| let var = receiver.var; |
| quote!(#ampersand #lifetime #mutability #var) |
| } else { |
| let ty = &receiver.ty; |
| quote!(#ampersand #lifetime #mutability #ty) |
| } |
| } |
| |
| fn combine_errors(errors: Vec<Error>) -> Result<()> { |
| let mut iter = errors.into_iter(); |
| let mut all_errors = match iter.next() { |
| Some(err) => err, |
| None => return Ok(()), |
| }; |
| for err in iter { |
| all_errors.combine(err); |
| } |
| Err(all_errors) |
| } |
| |
| fn describe(cx: &mut Check, ty: &Type) -> String { |
| match ty { |
| Type::Ident(ident) => { |
| if cx.types.structs.contains_key(ident) { |
| "struct".to_owned() |
| } else if cx.types.cxx.contains(ident) { |
| "C++ type".to_owned() |
| } else if cx.types.rust.contains(ident) { |
| "opaque Rust type".to_owned() |
| } else if Atom::from(ident) == Some(CxxString) { |
| "C++ string".to_owned() |
| } else { |
| ident.to_string() |
| } |
| } |
| Type::RustBox(_) => "Box".to_owned(), |
| Type::RustVec(_) => "Vec".to_owned(), |
| Type::UniquePtr(_) => "unique_ptr".to_owned(), |
| Type::Ref(_) => "reference".to_owned(), |
| Type::Str(_) => "&str".to_owned(), |
| Type::CxxVector(_) => "C++ vector".to_owned(), |
| Type::Slice(_) => "slice".to_owned(), |
| Type::SliceRefU8(_) => "&[u8]".to_owned(), |
| Type::Fn(_) => "function pointer".to_owned(), |
| Type::Void(_) => "()".to_owned(), |
| } |
| } |