Vendor things

third-party/vendor/bindgen/codegen/helpers.rs

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+//! Helpers for code generation that don't need macro expansion.
+
+use crate::ir::context::BindgenContext;
+use crate::ir::layout::Layout;
+use proc_macro2::{Ident, Span, TokenStream};
+use quote::TokenStreamExt;
+
+pub mod attributes {
+    use proc_macro2::{Ident, Span, TokenStream};
+    use std::str::FromStr;
+
+    pub fn repr(which: &str) -> TokenStream {
+        let which = Ident::new(which, Span::call_site());
+        quote! {
+            #[repr( #which )]
+        }
+    }
+
+    pub 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 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 fn inline() -> TokenStream {
+        quote! {
+            #[inline]
+        }
+    }
+
+    pub fn must_use() -> TokenStream {
+        quote! {
+            #[must_use]
+        }
+    }
+
+    pub fn non_exhaustive() -> TokenStream {
+        quote! {
+            #[non_exhaustive]
+        }
+    }
+
+    pub fn doc(comment: String) -> TokenStream {
+        if comment.is_empty() {
+            quote!()
+        } else {
+            quote!(#[doc = #comment])
+        }
+    }
+
+    pub fn link_name(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 = format!("\u{1}{}", name);
+        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 fn blob(ctx: &BindgenContext, layout: Layout) -> TokenStream {
+    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_name = match opaque.known_rust_type_for_array(ctx) {
+        Some(ty) => ty,
+        None => {
+            warn!("Found unknown alignment on code generation!");
+            "u8"
+        }
+    };
+
+    let ty_name = Ident::new(ty_name, Span::call_site());
+
+    let data_len = opaque.array_size(ctx).unwrap_or(layout.size);
+
+    if data_len == 1 {
+        quote! {
+            #ty_name
+        }
+    } else {
+        quote! {
+            [ #ty_name ; #data_len ]
+        }
+    }
+}
+
+/// Integer type of the same size as the given `Layout`.
+pub fn integer_type(
+    ctx: &BindgenContext,
+    layout: Layout,
+) -> Option<TokenStream> {
+    let name = Layout::known_type_for_size(ctx, layout.size)?;
+    let name = Ident::new(name, Span::call_site());
+    Some(quote! { #name })
+}
+
+/// Generates a bitfield allocation unit type for a type with the given `Layout`.
+pub fn bitfield_unit(ctx: &BindgenContext, layout: Layout) -> TokenStream {
+    let mut tokens = quote! {};
+
+    if ctx.options().enable_cxx_namespaces {
+        tokens.append_all(quote! { root:: });
+    }
+
+    let size = layout.size;
+    tokens.append_all(quote! {
+        __BindgenBitfieldUnit<[u8; #size]>
+    });
+
+    tokens
+}
+
+pub mod ast_ty {
+    use crate::ir::context::BindgenContext;
+    use crate::ir::function::FunctionSig;
+    use crate::ir::layout::Layout;
+    use crate::ir::ty::FloatKind;
+    use proc_macro2::{self, TokenStream};
+    use std::str::FromStr;
+
+    pub fn c_void(ctx: &BindgenContext) -> TokenStream {
+        // ctypes_prefix takes precedence
+        match ctx.options().ctypes_prefix {
+            Some(ref prefix) => {
+                let prefix = TokenStream::from_str(prefix.as_str()).unwrap();
+                quote! {
+                    #prefix::c_void
+                }
+            }
+            None => {
+                if ctx.options().use_core &&
+                    ctx.options().rust_features.core_ffi_c_void
+                {
+                    quote! { ::core::ffi::c_void }
+                } else {
+                    quote! { ::std::os::raw::c_void }
+                }
+            }
+        }
+    }
+
+    pub fn raw_type(ctx: &BindgenContext, name: &str) -> TokenStream {
+        let ident = ctx.rust_ident_raw(name);
+        match ctx.options().ctypes_prefix {
+            Some(ref prefix) => {
+                let prefix = TokenStream::from_str(prefix.as_str()).unwrap();
+                quote! {
+                    #prefix::#ident
+                }
+            }
+            None => {
+                if ctx.options().use_core &&
+                    ctx.options().rust_features().core_ffi_c
+                {
+                    quote! {
+                        ::core::ffi::#ident
+                    }
+                } else {
+                    quote! {
+                        ::std::os::raw::#ident
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn float_kind_rust_type(
+        ctx: &BindgenContext,
+        fk: FloatKind,
+        layout: Option<Layout>,
+    ) -> TokenStream {
+        // 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::Float, true) => quote! { f32 },
+            (FloatKind::Double, true) => 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 => quote! { f32 },
+                            8 => quote! { f64 },
+                            // TODO(emilio): If rust ever gains f128 we should
+                            // use it here and below.
+                            _ => super::integer_type(ctx, layout)
+                                .unwrap_or(quote! { f64 }),
+                        }
+                    }
+                    None => {
+                        debug_assert!(
+                            false,
+                            "How didn't we know the layout for a primitive type?"
+                        );
+                        quote! { f64 }
+                    }
+                }
+            }
+            (FloatKind::Float128, _) => {
+                if ctx.options().rust_features.i128_and_u128 {
+                    quote! { u128 }
+                } else {
+                    quote! { [u64; 2] }
+                }
+            }
+        }
+    }
+
+    pub 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 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 fn byte_array_expr(bytes: &[u8]) -> TokenStream {
+        let mut bytes: Vec<_> = bytes.to_vec();
+        bytes.push(0);
+        quote! { [ #(#bytes),* ] }
+    }
+
+    pub fn cstr_expr(mut string: String) -> TokenStream {
+        string.push('\0');
+        let b = proc_macro2::Literal::byte_string(string.as_bytes());
+        quote! {
+            #b
+        }
+    }
+
+    pub 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 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()
+    }
+}