Update quote and proc-macro.

I give up on the doc comments. This is a rebase of #1334 keeping the formatting
of the comments and using TokenStream::from_str instead because one can hope.

Fixes #1407.

1 files changed, 31 insertions, 36 deletions

diff --git a/src/codegen/helpers.rs b/src/codegen/helpers.rs
index 02909d57..aea4b1fb 100644
--- a/src/codegen/helpers.rs
+++ b/src/codegen/helpers.rs
@@ -2,58 +2,54 @@
 
 use ir::context::BindgenContext;
 use ir::layout::Layout;
-use quote;
-use proc_macro2::{Term, Span};
+use proc_macro2::{self, Ident, Span};
+use quote::TokenStreamExt;
 
 pub mod attributes {
-    use quote;
-    use proc_macro2::{Term, Span};
+    use proc_macro2::{self, Ident, Span};
 
-    pub fn repr(which: &str) -> quote::Tokens {
-        let which = Term::new(which, Span::call_site());
+    pub fn repr(which: &str) -> proc_macro2::TokenStream {
+        let which = Ident::new(which, Span::call_site());
         quote! {
             #[repr( #which )]
         }
     }
 
-    pub fn repr_list(which_ones: &[&str]) -> quote::Tokens {
-        let which_ones = which_ones.iter().cloned().map(|one| Term::new(one, Span::call_site()));
+    pub fn repr_list(which_ones: &[&str]) -> proc_macro2::TokenStream {
+        let which_ones = which_ones.iter().cloned().map(|one| Ident::new(one, Span::call_site()));
         quote! {
             #[repr( #( #which_ones ),* )]
         }
     }
 
-    pub fn derives(which_ones: &[&str]) -> quote::Tokens {
-        let which_ones = which_ones.iter().cloned().map(|one| Term::new(one, Span::call_site()));
+    pub fn derives(which_ones: &[&str]) -> proc_macro2::TokenStream {
+        let which_ones = which_ones.iter().cloned().map(|one| Ident::new(one, Span::call_site()));
         quote! {
             #[derive( #( #which_ones ),* )]
         }
     }
 
-    pub fn inline() -> quote::Tokens {
+    pub fn inline() -> proc_macro2::TokenStream {
         quote! {
             #[inline]
         }
     }
 
-    pub fn must_use() -> quote::Tokens {
+    pub fn must_use() -> proc_macro2::TokenStream {
         quote! {
             #[must_use]
         }
     }
 
-    pub fn doc(comment: String) -> quote::Tokens {
-        // Doc comments are already preprocessed into nice `///` formats by the
-        // time they get here. Just make sure that we have newlines around it so
-        // that nothing else gets wrapped into the comment.
-        let mut tokens = quote! {};
-        tokens.append(Term::new("\n", Span::call_site()));
-        tokens.append(Term::new(&comment, Span::call_site()));
-        tokens.append(Term::new("\n", Span::call_site()));
-        tokens
+    pub fn doc(comment: String) -> proc_macro2::TokenStream {
+        use std::str::FromStr;
+
+        // NOTE(emilio): By this point comments are already preprocessed and in
+        // `///` form. Quote turns them into `#[doc]` comments, but oh well.
+        proc_macro2::TokenStream::from_str(&comment).unwrap()
     }
 
-    pub fn link_name(name: &str) -> quote::Tokens {
+    pub fn link_name(name: &str) -> proc_macro2::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);
@@ -65,7 +61,7 @@ pub mod attributes {
 
 /// 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) -> quote::Tokens {
+pub fn blob(ctx: &BindgenContext, layout: Layout) -> proc_macro2::TokenStream {
     let opaque = layout.opaque();
 
     // FIXME(emilio, #412): We fall back to byte alignment, but there are
@@ -80,7 +76,7 @@ pub fn blob(ctx: &BindgenContext, layout: Layout) -> quote::Tokens {
         }
     };
 
-    let ty_name = Term::new(ty_name, Span::call_site());
+    let ty_name = Ident::new(ty_name, Span::call_site());
 
     let data_len = opaque.array_size(ctx).unwrap_or(layout.size);
 
@@ -96,14 +92,14 @@ pub fn blob(ctx: &BindgenContext, layout: Layout) -> quote::Tokens {
 }
 
 /// Integer type of the same size as the given `Layout`.
-pub fn integer_type(ctx: &BindgenContext, layout: Layout) -> Option<quote::Tokens> {
+pub fn integer_type(ctx: &BindgenContext, layout: Layout) -> Option<proc_macro2::TokenStream> {
     let name = Layout::known_type_for_size(ctx, layout.size)?;
-    let name = Term::new(name, Span::call_site());
+    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) -> quote::Tokens {
+pub fn bitfield_unit(ctx: &BindgenContext, layout: Layout) -> proc_macro2::TokenStream {
     let mut tokens = quote! {};
 
     if ctx.options().enable_cxx_namespaces {
@@ -130,10 +126,9 @@ pub mod ast_ty {
     use ir::function::FunctionSig;
     use ir::layout::Layout;
     use ir::ty::FloatKind;
-    use quote;
     use proc_macro2;
 
-    pub fn raw_type(ctx: &BindgenContext, name: &str) -> quote::Tokens {
+    pub fn raw_type(ctx: &BindgenContext, name: &str) -> proc_macro2::TokenStream {
         let ident = ctx.rust_ident_raw(name);
         match ctx.options().ctypes_prefix {
             Some(ref prefix) => {
@@ -152,7 +147,7 @@ pub mod ast_ty {
         ctx: &BindgenContext,
         fk: FloatKind,
         layout: Option<Layout>,
-    ) -> quote::Tokens {
+    ) -> proc_macro2::TokenStream {
         // TODO: we probably should take the type layout into account more
         // often?
         //
@@ -192,25 +187,25 @@ pub mod ast_ty {
         }
     }
 
-    pub fn int_expr(val: i64) -> quote::Tokens {
+    pub fn int_expr(val: i64) -> proc_macro2::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) -> quote::Tokens {
+    pub fn uint_expr(val: u64) -> proc_macro2::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]) -> quote::Tokens {
+    pub fn byte_array_expr(bytes: &[u8]) -> proc_macro2::TokenStream {
         let mut bytes: Vec<_> = bytes.iter().cloned().collect();
         bytes.push(0);
         quote! { [ #(#bytes),* ] }
     }
 
-    pub fn cstr_expr(mut string: String) -> quote::Tokens {
+    pub fn cstr_expr(mut string: String) -> proc_macro2::TokenStream {
         string.push('\0');
         let b = proc_macro2::Literal::byte_string(&string.as_bytes());
         quote! {
@@ -221,7 +216,7 @@ pub mod ast_ty {
     pub fn float_expr(
         ctx: &BindgenContext,
         f: f64,
-    ) -> Result<quote::Tokens, ()> {
+    ) -> Result<proc_macro2::TokenStream, ()> {
         if f.is_finite() {
             let val = proc_macro2::Literal::f64_unsuffixed(f);
 
@@ -255,7 +250,7 @@ pub mod ast_ty {
     pub fn arguments_from_signature(
         signature: &FunctionSig,
         ctx: &BindgenContext,
-    ) -> Vec<quote::Tokens> {
+    ) -> Vec<proc_macro2::TokenStream> {
         let mut unnamed_arguments = 0;
         signature
             .argument_types()