From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- rust/quote/README.md | 12 + rust/quote/ext.rs | 112 ++++ rust/quote/format.rs | 170 +++++ rust/quote/ident_fragment.rs | 90 +++ rust/quote/lib.rs | 1456 ++++++++++++++++++++++++++++++++++++++++++ rust/quote/runtime.rs | 494 ++++++++++++++ rust/quote/spanned.rs | 52 ++ rust/quote/to_tokens.rs | 273 ++++++++ 8 files changed, 2659 insertions(+) create mode 100644 rust/quote/README.md create mode 100644 rust/quote/ext.rs create mode 100644 rust/quote/format.rs create mode 100644 rust/quote/ident_fragment.rs create mode 100644 rust/quote/lib.rs create mode 100644 rust/quote/runtime.rs create mode 100644 rust/quote/spanned.rs create mode 100644 rust/quote/to_tokens.rs (limited to 'rust/quote') diff --git a/rust/quote/README.md b/rust/quote/README.md new file mode 100644 index 000000000..186123eff --- /dev/null +++ b/rust/quote/README.md @@ -0,0 +1,12 @@ +# `quote` + +These source files come from the Rust `quote` crate, version 1.0.40 +(released 2025-03-12), hosted in the +repository, licensed under "Apache-2.0 OR MIT" and only modified to add +the SPDX license identifiers. + +For copyright details, please see: + + https://github.com/dtolnay/quote/blob/1.0.40/README.md#license + https://github.com/dtolnay/quote/blob/1.0.40/LICENSE-APACHE + https://github.com/dtolnay/quote/blob/1.0.40/LICENSE-MIT diff --git a/rust/quote/ext.rs b/rust/quote/ext.rs new file mode 100644 index 000000000..977d2f0c5 --- /dev/null +++ b/rust/quote/ext.rs @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use super::ToTokens; +use core::iter; +use proc_macro2::{TokenStream, TokenTree}; + +/// TokenStream extension trait with methods for appending tokens. +/// +/// This trait is sealed and cannot be implemented outside of the `quote` crate. +pub trait TokenStreamExt: private::Sealed { + /// For use by `ToTokens` implementations. + /// + /// Appends the token specified to this list of tokens. + fn append(&mut self, token: U) + where + U: Into; + + /// For use by `ToTokens` implementations. + /// + /// ``` + /// # use quote::{quote, TokenStreamExt, ToTokens}; + /// # use proc_macro2::TokenStream; + /// # + /// struct X; + /// + /// impl ToTokens for X { + /// fn to_tokens(&self, tokens: &mut TokenStream) { + /// tokens.append_all(&[true, false]); + /// } + /// } + /// + /// let tokens = quote!(#X); + /// assert_eq!(tokens.to_string(), "true false"); + /// ``` + fn append_all(&mut self, iter: I) + where + I: IntoIterator, + I::Item: ToTokens; + + /// For use by `ToTokens` implementations. + /// + /// Appends all of the items in the iterator `I`, separated by the tokens + /// `U`. + fn append_separated(&mut self, iter: I, op: U) + where + I: IntoIterator, + I::Item: ToTokens, + U: ToTokens; + + /// For use by `ToTokens` implementations. + /// + /// Appends all tokens in the iterator `I`, appending `U` after each + /// element, including after the last element of the iterator. + fn append_terminated(&mut self, iter: I, term: U) + where + I: IntoIterator, + I::Item: ToTokens, + U: ToTokens; +} + +impl TokenStreamExt for TokenStream { + fn append(&mut self, token: U) + where + U: Into, + { + self.extend(iter::once(token.into())); + } + + fn append_all(&mut self, iter: I) + where + I: IntoIterator, + I::Item: ToTokens, + { + for token in iter { + token.to_tokens(self); + } + } + + fn append_separated(&mut self, iter: I, op: U) + where + I: IntoIterator, + I::Item: ToTokens, + U: ToTokens, + { + for (i, token) in iter.into_iter().enumerate() { + if i > 0 { + op.to_tokens(self); + } + token.to_tokens(self); + } + } + + fn append_terminated(&mut self, iter: I, term: U) + where + I: IntoIterator, + I::Item: ToTokens, + U: ToTokens, + { + for token in iter { + token.to_tokens(self); + term.to_tokens(self); + } + } +} + +mod private { + use proc_macro2::TokenStream; + + pub trait Sealed {} + + impl Sealed for TokenStream {} +} diff --git a/rust/quote/format.rs b/rust/quote/format.rs new file mode 100644 index 000000000..6e3d55b6e --- /dev/null +++ b/rust/quote/format.rs @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +/// Formatting macro for constructing `Ident`s. +/// +///
+/// +/// # Syntax +/// +/// Syntax is copied from the [`format!`] macro, supporting both positional and +/// named arguments. +/// +/// Only a limited set of formatting traits are supported. The current mapping +/// of format types to traits is: +/// +/// * `{}` ⇒ [`IdentFragment`] +/// * `{:o}` ⇒ [`Octal`](std::fmt::Octal) +/// * `{:x}` ⇒ [`LowerHex`](std::fmt::LowerHex) +/// * `{:X}` ⇒ [`UpperHex`](std::fmt::UpperHex) +/// * `{:b}` ⇒ [`Binary`](std::fmt::Binary) +/// +/// See [`std::fmt`] for more information. +/// +///
+/// +/// # IdentFragment +/// +/// Unlike `format!`, this macro uses the [`IdentFragment`] formatting trait by +/// default. This trait is like `Display`, with a few differences: +/// +/// * `IdentFragment` is only implemented for a limited set of types, such as +/// unsigned integers and strings. +/// * [`Ident`] arguments will have their `r#` prefixes stripped, if present. +/// +/// [`IdentFragment`]: crate::IdentFragment +/// [`Ident`]: proc_macro2::Ident +/// +///
+/// +/// # Hygiene +/// +/// The [`Span`] of the first `Ident` argument is used as the span of the final +/// identifier, falling back to [`Span::call_site`] when no identifiers are +/// provided. +/// +/// ``` +/// # use quote::format_ident; +/// # let ident = format_ident!("Ident"); +/// // If `ident` is an Ident, the span of `my_ident` will be inherited from it. +/// let my_ident = format_ident!("My{}{}", ident, "IsCool"); +/// assert_eq!(my_ident, "MyIdentIsCool"); +/// ``` +/// +/// Alternatively, the span can be overridden by passing the `span` named +/// argument. +/// +/// ``` +/// # use quote::format_ident; +/// # const IGNORE_TOKENS: &'static str = stringify! { +/// let my_span = /* ... */; +/// # }; +/// # let my_span = proc_macro2::Span::call_site(); +/// format_ident!("MyIdent", span = my_span); +/// ``` +/// +/// [`Span`]: proc_macro2::Span +/// [`Span::call_site`]: proc_macro2::Span::call_site +/// +///


+/// +/// # Panics +/// +/// This method will panic if the resulting formatted string is not a valid +/// identifier. +/// +///
+/// +/// # Examples +/// +/// Composing raw and non-raw identifiers: +/// ``` +/// # use quote::format_ident; +/// let my_ident = format_ident!("My{}", "Ident"); +/// assert_eq!(my_ident, "MyIdent"); +/// +/// let raw = format_ident!("r#Raw"); +/// assert_eq!(raw, "r#Raw"); +/// +/// let my_ident_raw = format_ident!("{}Is{}", my_ident, raw); +/// assert_eq!(my_ident_raw, "MyIdentIsRaw"); +/// ``` +/// +/// Integer formatting options: +/// ``` +/// # use quote::format_ident; +/// let num: u32 = 10; +/// +/// let decimal = format_ident!("Id_{}", num); +/// assert_eq!(decimal, "Id_10"); +/// +/// let octal = format_ident!("Id_{:o}", num); +/// assert_eq!(octal, "Id_12"); +/// +/// let binary = format_ident!("Id_{:b}", num); +/// assert_eq!(binary, "Id_1010"); +/// +/// let lower_hex = format_ident!("Id_{:x}", num); +/// assert_eq!(lower_hex, "Id_a"); +/// +/// let upper_hex = format_ident!("Id_{:X}", num); +/// assert_eq!(upper_hex, "Id_A"); +/// ``` +#[macro_export] +macro_rules! format_ident { + ($fmt:expr) => { + $crate::format_ident_impl!([ + $crate::__private::Option::None, + $fmt + ]) + }; + + ($fmt:expr, $($rest:tt)*) => { + $crate::format_ident_impl!([ + $crate::__private::Option::None, + $fmt + ] $($rest)*) + }; +} + +#[macro_export] +#[doc(hidden)] +macro_rules! format_ident_impl { + // Final state + ([$span:expr, $($fmt:tt)*]) => { + $crate::__private::mk_ident( + &$crate::__private::format!($($fmt)*), + $span, + ) + }; + + // Span argument + ([$old:expr, $($fmt:tt)*] span = $span:expr) => { + $crate::format_ident_impl!([$old, $($fmt)*] span = $span,) + }; + ([$old:expr, $($fmt:tt)*] span = $span:expr, $($rest:tt)*) => { + $crate::format_ident_impl!([ + $crate::__private::Option::Some::<$crate::__private::Span>($span), + $($fmt)* + ] $($rest)*) + }; + + // Named argument + ([$span:expr, $($fmt:tt)*] $name:ident = $arg:expr) => { + $crate::format_ident_impl!([$span, $($fmt)*] $name = $arg,) + }; + ([$span:expr, $($fmt:tt)*] $name:ident = $arg:expr, $($rest:tt)*) => { + match $crate::__private::IdentFragmentAdapter(&$arg) { + arg => $crate::format_ident_impl!([$span.or(arg.span()), $($fmt)*, $name = arg] $($rest)*), + } + }; + + // Positional argument + ([$span:expr, $($fmt:tt)*] $arg:expr) => { + $crate::format_ident_impl!([$span, $($fmt)*] $arg,) + }; + ([$span:expr, $($fmt:tt)*] $arg:expr, $($rest:tt)*) => { + match $crate::__private::IdentFragmentAdapter(&$arg) { + arg => $crate::format_ident_impl!([$span.or(arg.span()), $($fmt)*, arg] $($rest)*), + } + }; +} diff --git a/rust/quote/ident_fragment.rs b/rust/quote/ident_fragment.rs new file mode 100644 index 000000000..d98106f17 --- /dev/null +++ b/rust/quote/ident_fragment.rs @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use alloc::borrow::Cow; +use core::fmt; +use proc_macro2::{Ident, Span}; + +/// Specialized formatting trait used by `format_ident!`. +/// +/// [`Ident`] arguments formatted using this trait will have their `r#` prefix +/// stripped, if present. +/// +/// See [`format_ident!`] for more information. +/// +/// [`format_ident!`]: crate::format_ident +pub trait IdentFragment { + /// Format this value as an identifier fragment. + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result; + + /// Span associated with this `IdentFragment`. + /// + /// If non-`None`, may be inherited by formatted identifiers. + fn span(&self) -> Option { + None + } +} + +impl IdentFragment for &T { + fn span(&self) -> Option { + ::span(*self) + } + + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + IdentFragment::fmt(*self, f) + } +} + +impl IdentFragment for &mut T { + fn span(&self) -> Option { + ::span(*self) + } + + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + IdentFragment::fmt(*self, f) + } +} + +impl IdentFragment for Ident { + fn span(&self) -> Option { + Some(self.span()) + } + + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + let id = self.to_string(); + if let Some(id) = id.strip_prefix("r#") { + fmt::Display::fmt(id, f) + } else { + fmt::Display::fmt(&id[..], f) + } + } +} + +impl IdentFragment for Cow<'_, T> +where + T: IdentFragment + ToOwned + ?Sized, +{ + fn span(&self) -> Option { + T::span(self) + } + + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + T::fmt(self, f) + } +} + +// Limited set of types which this is implemented for, as we want to avoid types +// which will often include non-identifier characters in their `Display` impl. +macro_rules! ident_fragment_display { + ($($T:ty),*) => { + $( + impl IdentFragment for $T { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::Display::fmt(self, f) + } + } + )* + }; +} + +ident_fragment_display!(bool, str, String, char); +ident_fragment_display!(u8, u16, u32, u64, u128, usize); diff --git a/rust/quote/lib.rs b/rust/quote/lib.rs new file mode 100644 index 000000000..cc1637660 --- /dev/null +++ b/rust/quote/lib.rs @@ -0,0 +1,1456 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +//! [![github]](https://github.com/dtolnay/quote) [![crates-io]](https://crates.io/crates/quote) [![docs-rs]](https://docs.rs/quote) +//! +//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github +//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust +//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs +//! +//!
+//! +//! This crate provides the [`quote!`] macro for turning Rust syntax tree data +//! structures into tokens of source code. +//! +//! Procedural macros in Rust receive a stream of tokens as input, execute +//! arbitrary Rust code to determine how to manipulate those tokens, and produce +//! a stream of tokens to hand back to the compiler to compile into the caller's +//! crate. Quasi-quoting is a solution to one piece of that — producing +//! tokens to return to the compiler. +//! +//! The idea of quasi-quoting is that we write *code* that we treat as *data*. +//! Within the `quote!` macro, we can write what looks like code to our text +//! editor or IDE. We get all the benefits of the editor's brace matching, +//! syntax highlighting, indentation, and maybe autocompletion. But rather than +//! compiling that as code into the current crate, we can treat it as data, pass +//! it around, mutate it, and eventually hand it back to the compiler as tokens +//! to compile into the macro caller's crate. +//! +//! This crate is motivated by the procedural macro use case, but is a +//! general-purpose Rust quasi-quoting library and is not specific to procedural +//! macros. +//! +//! ```toml +//! [dependencies] +//! quote = "1.0" +//! ``` +//! +//!
+//! +//! # Example +//! +//! The following quasi-quoted block of code is something you might find in [a] +//! procedural macro having to do with data structure serialization. The `#var` +//! syntax performs interpolation of runtime variables into the quoted tokens. +//! Check out the documentation of the [`quote!`] macro for more detail about +//! the syntax. See also the [`quote_spanned!`] macro which is important for +//! implementing hygienic procedural macros. +//! +//! [a]: https://serde.rs/ +//! +//! ``` +//! # use quote::quote; +//! # +//! # let generics = ""; +//! # let where_clause = ""; +//! # let field_ty = ""; +//! # let item_ty = ""; +//! # let path = ""; +//! # let value = ""; +//! # +//! let tokens = quote! { +//! struct SerializeWith #generics #where_clause { +//! value: &'a #field_ty, +//! phantom: core::marker::PhantomData<#item_ty>, +//! } +//! +//! impl #generics serde::Serialize for SerializeWith #generics #where_clause { +//! fn serialize(&self, serializer: S) -> Result +//! where +//! S: serde::Serializer, +//! { +//! #path(self.value, serializer) +//! } +//! } +//! +//! SerializeWith { +//! value: #value, +//! phantom: core::marker::PhantomData::<#item_ty>, +//! } +//! }; +//! ``` +//! +//!
+//! +//! # Non-macro code generators +//! +//! When using `quote` in a build.rs or main.rs and writing the output out to a +//! file, consider having the code generator pass the tokens through +//! [prettyplease] before writing. This way if an error occurs in the generated +//! code it is convenient for a human to read and debug. +//! +//! [prettyplease]: https://github.com/dtolnay/prettyplease + +// Quote types in rustdoc of other crates get linked to here. +#![doc(html_root_url = "https://docs.rs/quote/1.0.40")] +#![allow( + clippy::doc_markdown, + clippy::elidable_lifetime_names, + clippy::missing_errors_doc, + clippy::missing_panics_doc, + clippy::module_name_repetitions, + clippy::needless_lifetimes, + // false positive https://github.com/rust-lang/rust-clippy/issues/6983 + clippy::wrong_self_convention, +)] + +extern crate alloc; + +#[cfg(feature = "proc-macro")] +extern crate proc_macro; + +mod ext; +mod format; +mod ident_fragment; +mod to_tokens; + +// Not public API. +#[doc(hidden)] +#[path = "runtime.rs"] +pub mod __private; + +pub use crate::ext::TokenStreamExt; +pub use crate::ident_fragment::IdentFragment; +pub use crate::to_tokens::ToTokens; + +// Not public API. +#[doc(hidden)] +pub mod spanned; + +macro_rules! __quote { + ($quote:item) => { + /// The whole point. + /// + /// Performs variable interpolation against the input and produces it as + /// [`proc_macro2::TokenStream`]. + /// + /// Note: for returning tokens to the compiler in a procedural macro, use + /// `.into()` on the result to convert to [`proc_macro::TokenStream`]. + /// + ///
+ /// + /// # Interpolation + /// + /// Variable interpolation is done with `#var` (similar to `$var` in + /// `macro_rules!` macros). This grabs the `var` variable that is currently in + /// scope and inserts it in that location in the output tokens. Any type + /// implementing the [`ToTokens`] trait can be interpolated. This includes most + /// Rust primitive types as well as most of the syntax tree types from the [Syn] + /// crate. + /// + /// [Syn]: https://github.com/dtolnay/syn + /// + /// Repetition is done using `#(...)*` or `#(...),*` again similar to + /// `macro_rules!`. This iterates through the elements of any variable + /// interpolated within the repetition and inserts a copy of the repetition body + /// for each one. The variables in an interpolation may be a `Vec`, slice, + /// `BTreeSet`, or any `Iterator`. + /// + /// - `#(#var)*` — no separators + /// - `#(#var),*` — the character before the asterisk is used as a separator + /// - `#( struct #var; )*` — the repetition can contain other tokens + /// - `#( #k => println!("{}", #v), )*` — even multiple interpolations + /// + ///
+ /// + /// # Hygiene + /// + /// Any interpolated tokens preserve the `Span` information provided by their + /// `ToTokens` implementation. Tokens that originate within the `quote!` + /// invocation are spanned with [`Span::call_site()`]. + /// + /// [`Span::call_site()`]: proc_macro2::Span::call_site + /// + /// A different span can be provided through the [`quote_spanned!`] macro. + /// + ///
+ /// + /// # Return type + /// + /// The macro evaluates to an expression of type `proc_macro2::TokenStream`. + /// Meanwhile Rust procedural macros are expected to return the type + /// `proc_macro::TokenStream`. + /// + /// The difference between the two types is that `proc_macro` types are entirely + /// specific to procedural macros and cannot ever exist in code outside of a + /// procedural macro, while `proc_macro2` types may exist anywhere including + /// tests and non-macro code like main.rs and build.rs. This is why even the + /// procedural macro ecosystem is largely built around `proc_macro2`, because + /// that ensures the libraries are unit testable and accessible in non-macro + /// contexts. + /// + /// There is a [`From`]-conversion in both directions so returning the output of + /// `quote!` from a procedural macro usually looks like `tokens.into()` or + /// `proc_macro::TokenStream::from(tokens)`. + /// + ///
+ /// + /// # Examples + /// + /// ### Procedural macro + /// + /// The structure of a basic procedural macro is as follows. Refer to the [Syn] + /// crate for further useful guidance on using `quote!` as part of a procedural + /// macro. + /// + /// [Syn]: https://github.com/dtolnay/syn + /// + /// ``` + /// # #[cfg(any())] + /// extern crate proc_macro; + /// # extern crate proc_macro2; + /// + /// # #[cfg(any())] + /// use proc_macro::TokenStream; + /// # use proc_macro2::TokenStream; + /// use quote::quote; + /// + /// # const IGNORE_TOKENS: &'static str = stringify! { + /// #[proc_macro_derive(HeapSize)] + /// # }; + /// pub fn derive_heap_size(input: TokenStream) -> TokenStream { + /// // Parse the input and figure out what implementation to generate... + /// # const IGNORE_TOKENS: &'static str = stringify! { + /// let name = /* ... */; + /// let expr = /* ... */; + /// # }; + /// # + /// # let name = 0; + /// # let expr = 0; + /// + /// let expanded = quote! { + /// // The generated impl. + /// impl heapsize::HeapSize for #name { + /// fn heap_size_of_children(&self) -> usize { + /// #expr + /// } + /// } + /// }; + /// + /// // Hand the output tokens back to the compiler. + /// TokenStream::from(expanded) + /// } + /// ``` + /// + ///


+ /// + /// ### Combining quoted fragments + /// + /// Usually you don't end up constructing an entire final `TokenStream` in one + /// piece. Different parts may come from different helper functions. The tokens + /// produced by `quote!` themselves implement `ToTokens` and so can be + /// interpolated into later `quote!` invocations to build up a final result. + /// + /// ``` + /// # use quote::quote; + /// # + /// let type_definition = quote! {...}; + /// let methods = quote! {...}; + /// + /// let tokens = quote! { + /// #type_definition + /// #methods + /// }; + /// ``` + /// + ///


+ /// + /// ### Constructing identifiers + /// + /// Suppose we have an identifier `ident` which came from somewhere in a macro + /// input and we need to modify it in some way for the macro output. Let's + /// consider prepending the identifier with an underscore. + /// + /// Simply interpolating the identifier next to an underscore will not have the + /// behavior of concatenating them. The underscore and the identifier will + /// continue to be two separate tokens as if you had written `_ x`. + /// + /// ``` + /// # use proc_macro2::{self as syn, Span}; + /// # use quote::quote; + /// # + /// # let ident = syn::Ident::new("i", Span::call_site()); + /// # + /// // incorrect + /// quote! { + /// let mut _#ident = 0; + /// } + /// # ; + /// ``` + /// + /// The solution is to build a new identifier token with the correct value. As + /// this is such a common case, the [`format_ident!`] macro provides a + /// convenient utility for doing so correctly. + /// + /// ``` + /// # use proc_macro2::{Ident, Span}; + /// # use quote::{format_ident, quote}; + /// # + /// # let ident = Ident::new("i", Span::call_site()); + /// # + /// let varname = format_ident!("_{}", ident); + /// quote! { + /// let mut #varname = 0; + /// } + /// # ; + /// ``` + /// + /// Alternatively, the APIs provided by Syn and proc-macro2 can be used to + /// directly build the identifier. This is roughly equivalent to the above, but + /// will not handle `ident` being a raw identifier. + /// + /// ``` + /// # use proc_macro2::{self as syn, Span}; + /// # use quote::quote; + /// # + /// # let ident = syn::Ident::new("i", Span::call_site()); + /// # + /// let concatenated = format!("_{}", ident); + /// let varname = syn::Ident::new(&concatenated, ident.span()); + /// quote! { + /// let mut #varname = 0; + /// } + /// # ; + /// ``` + /// + ///


+ /// + /// ### Making method calls + /// + /// Let's say our macro requires some type specified in the macro input to have + /// a constructor called `new`. We have the type in a variable called + /// `field_type` of type `syn::Type` and want to invoke the constructor. + /// + /// ``` + /// # use quote::quote; + /// # + /// # let field_type = quote!(...); + /// # + /// // incorrect + /// quote! { + /// let value = #field_type::new(); + /// } + /// # ; + /// ``` + /// + /// This works only sometimes. If `field_type` is `String`, the expanded code + /// contains `String::new()` which is fine. But if `field_type` is something + /// like `Vec` then the expanded code is `Vec::new()` which is invalid + /// syntax. Ordinarily in handwritten Rust we would write `Vec::::new()` + /// but for macros often the following is more convenient. + /// + /// ``` + /// # use quote::quote; + /// # + /// # let field_type = quote!(...); + /// # + /// quote! { + /// let value = <#field_type>::new(); + /// } + /// # ; + /// ``` + /// + /// This expands to `>::new()` which behaves correctly. + /// + /// A similar pattern is appropriate for trait methods. + /// + /// ``` + /// # use quote::quote; + /// # + /// # let field_type = quote!(...); + /// # + /// quote! { + /// let value = <#field_type as core::default::Default>::default(); + /// } + /// # ; + /// ``` + /// + ///


+ /// + /// ### Interpolating text inside of doc comments + /// + /// Neither doc comments nor string literals get interpolation behavior in + /// quote: + /// + /// ```compile_fail + /// quote! { + /// /// try to interpolate: #ident + /// /// + /// /// ... + /// } + /// ``` + /// + /// ```compile_fail + /// quote! { + /// #[doc = "try to interpolate: #ident"] + /// } + /// ``` + /// + /// Instead the best way to build doc comments that involve variables is by + /// formatting the doc string literal outside of quote. + /// + /// ```rust + /// # use proc_macro2::{Ident, Span}; + /// # use quote::quote; + /// # + /// # const IGNORE: &str = stringify! { + /// let msg = format!(...); + /// # }; + /// # + /// # let ident = Ident::new("var", Span::call_site()); + /// # let msg = format!("try to interpolate: {}", ident); + /// quote! { + /// #[doc = #msg] + /// /// + /// /// ... + /// } + /// # ; + /// ``` + /// + ///


+ /// + /// ### Indexing into a tuple struct + /// + /// When interpolating indices of a tuple or tuple struct, we need them not to + /// appears suffixed as integer literals by interpolating them as [`syn::Index`] + /// instead. + /// + /// [`syn::Index`]: https://docs.rs/syn/2.0/syn/struct.Index.html + /// + /// ```compile_fail + /// let i = 0usize..self.fields.len(); + /// + /// // expands to 0 + self.0usize.heap_size() + self.1usize.heap_size() + ... + /// // which is not valid syntax + /// quote! { + /// 0 #( + self.#i.heap_size() )* + /// } + /// ``` + /// + /// ``` + /// # use proc_macro2::{Ident, TokenStream}; + /// # use quote::quote; + /// # + /// # mod syn { + /// # use proc_macro2::{Literal, TokenStream}; + /// # use quote::{ToTokens, TokenStreamExt}; + /// # + /// # pub struct Index(usize); + /// # + /// # impl From for Index { + /// # fn from(i: usize) -> Self { + /// # Index(i) + /// # } + /// # } + /// # + /// # impl ToTokens for Index { + /// # fn to_tokens(&self, tokens: &mut TokenStream) { + /// # tokens.append(Literal::usize_unsuffixed(self.0)); + /// # } + /// # } + /// # } + /// # + /// # struct Struct { + /// # fields: Vec, + /// # } + /// # + /// # impl Struct { + /// # fn example(&self) -> TokenStream { + /// let i = (0..self.fields.len()).map(syn::Index::from); + /// + /// // expands to 0 + self.0.heap_size() + self.1.heap_size() + ... + /// quote! { + /// 0 #( + self.#i.heap_size() )* + /// } + /// # } + /// # } + /// ``` + $quote + }; +} + +#[cfg(doc)] +__quote![ + #[macro_export] + macro_rules! quote { + ($($tt:tt)*) => { + ... + }; + } +]; + +#[cfg(not(doc))] +__quote![ + #[macro_export] + macro_rules! quote { + () => { + $crate::__private::TokenStream::new() + }; + + // Special case rule for a single tt, for performance. + ($tt:tt) => {{ + let mut _s = $crate::__private::TokenStream::new(); + $crate::quote_token!{$tt _s} + _s + }}; + + // Special case rules for two tts, for performance. + (# $var:ident) => {{ + let mut _s = $crate::__private::TokenStream::new(); + $crate::ToTokens::to_tokens(&$var, &mut _s); + _s + }}; + ($tt1:tt $tt2:tt) => {{ + let mut _s = $crate::__private::TokenStream::new(); + $crate::quote_token!{$tt1 _s} + $crate::quote_token!{$tt2 _s} + _s + }}; + + // Rule for any other number of tokens. + ($($tt:tt)*) => {{ + let mut _s = $crate::__private::TokenStream::new(); + $crate::quote_each_token!{_s $($tt)*} + _s + }}; + } +]; + +macro_rules! __quote_spanned { + ($quote_spanned:item) => { + /// Same as `quote!`, but applies a given span to all tokens originating within + /// the macro invocation. + /// + ///
+ /// + /// # Syntax + /// + /// A span expression of type [`Span`], followed by `=>`, followed by the tokens + /// to quote. The span expression should be brief — use a variable for + /// anything more than a few characters. There should be no space before the + /// `=>` token. + /// + /// [`Span`]: proc_macro2::Span + /// + /// ``` + /// # use proc_macro2::Span; + /// # use quote::quote_spanned; + /// # + /// # const IGNORE_TOKENS: &'static str = stringify! { + /// let span = /* ... */; + /// # }; + /// # let span = Span::call_site(); + /// # let init = 0; + /// + /// // On one line, use parentheses. + /// let tokens = quote_spanned!(span=> Box::into_raw(Box::new(#init))); + /// + /// // On multiple lines, place the span at the top and use braces. + /// let tokens = quote_spanned! {span=> + /// Box::into_raw(Box::new(#init)) + /// }; + /// ``` + /// + /// The lack of space before the `=>` should look jarring to Rust programmers + /// and this is intentional. The formatting is designed to be visibly + /// off-balance and draw the eye a particular way, due to the span expression + /// being evaluated in the context of the procedural macro and the remaining + /// tokens being evaluated in the generated code. + /// + ///
+ /// + /// # Hygiene + /// + /// Any interpolated tokens preserve the `Span` information provided by their + /// `ToTokens` implementation. Tokens that originate within the `quote_spanned!` + /// invocation are spanned with the given span argument. + /// + ///
+ /// + /// # Example + /// + /// The following procedural macro code uses `quote_spanned!` to assert that a + /// particular Rust type implements the [`Sync`] trait so that references can be + /// safely shared between threads. + /// + /// ``` + /// # use quote::{quote_spanned, TokenStreamExt, ToTokens}; + /// # use proc_macro2::{Span, TokenStream}; + /// # + /// # struct Type; + /// # + /// # impl Type { + /// # fn span(&self) -> Span { + /// # Span::call_site() + /// # } + /// # } + /// # + /// # impl ToTokens for Type { + /// # fn to_tokens(&self, _tokens: &mut TokenStream) {} + /// # } + /// # + /// # let ty = Type; + /// # let call_site = Span::call_site(); + /// # + /// let ty_span = ty.span(); + /// let assert_sync = quote_spanned! {ty_span=> + /// struct _AssertSync where #ty: Sync; + /// }; + /// ``` + /// + /// If the assertion fails, the user will see an error like the following. The + /// input span of their type is highlighted in the error. + /// + /// ```text + /// error[E0277]: the trait bound `*const (): std::marker::Sync` is not satisfied + /// --> src/main.rs:10:21 + /// | + /// 10 | static ref PTR: *const () = &(); + /// | ^^^^^^^^^ `*const ()` cannot be shared between threads safely + /// ``` + /// + /// In this example it is important for the where-clause to be spanned with the + /// line/column information of the user's input type so that error messages are + /// placed appropriately by the compiler. + $quote_spanned + }; +} + +#[cfg(doc)] +__quote_spanned![ + #[macro_export] + macro_rules! quote_spanned { + ($span:expr=> $($tt:tt)*) => { + ... + }; + } +]; + +#[cfg(not(doc))] +__quote_spanned![ + #[macro_export] + macro_rules! quote_spanned { + ($span:expr=>) => {{ + let _: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); + $crate::__private::TokenStream::new() + }}; + + // Special case rule for a single tt, for performance. + ($span:expr=> $tt:tt) => {{ + let mut _s = $crate::__private::TokenStream::new(); + let _span: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); + $crate::quote_token_spanned!{$tt _s _span} + _s + }}; + + // Special case rules for two tts, for performance. + ($span:expr=> # $var:ident) => {{ + let mut _s = $crate::__private::TokenStream::new(); + let _: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); + $crate::ToTokens::to_tokens(&$var, &mut _s); + _s + }}; + ($span:expr=> $tt1:tt $tt2:tt) => {{ + let mut _s = $crate::__private::TokenStream::new(); + let _span: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); + $crate::quote_token_spanned!{$tt1 _s _span} + $crate::quote_token_spanned!{$tt2 _s _span} + _s + }}; + + // Rule for any other number of tokens. + ($span:expr=> $($tt:tt)*) => {{ + let mut _s = $crate::__private::TokenStream::new(); + let _span: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); + $crate::quote_each_token_spanned!{_s _span $($tt)*} + _s + }}; + } +]; + +// Extract the names of all #metavariables and pass them to the $call macro. +// +// in: pounded_var_names!(then!(...) a #b c #( #d )* #e) +// out: then!(... b); +// then!(... d); +// then!(... e); +#[macro_export] +#[doc(hidden)] +macro_rules! pounded_var_names { + ($call:ident! $extra:tt $($tts:tt)*) => { + $crate::pounded_var_names_with_context!{$call! $extra + (@ $($tts)*) + ($($tts)* @) + } + }; +} + +#[macro_export] +#[doc(hidden)] +macro_rules! pounded_var_names_with_context { + ($call:ident! $extra:tt ($($b1:tt)*) ($($curr:tt)*)) => { + $( + $crate::pounded_var_with_context!{$call! $extra $b1 $curr} + )* + }; +} + +#[macro_export] +#[doc(hidden)] +macro_rules! pounded_var_with_context { + ($call:ident! $extra:tt $b1:tt ( $($inner:tt)* )) => { + $crate::pounded_var_names!{$call! $extra $($inner)*} + }; + + ($call:ident! $extra:tt $b1:tt [ $($inner:tt)* ]) => { + $crate::pounded_var_names!{$call! $extra $($inner)*} + }; + + ($call:ident! $extra:tt $b1:tt { $($inner:tt)* }) => { + $crate::pounded_var_names!{$call! $extra $($inner)*} + }; + + ($call:ident!($($extra:tt)*) # $var:ident) => { + $crate::$call!($($extra)* $var); + }; + + ($call:ident! $extra:tt $b1:tt $curr:tt) => {}; +} + +#[macro_export] +#[doc(hidden)] +macro_rules! quote_bind_into_iter { + ($has_iter:ident $var:ident) => { + // `mut` may be unused if $var occurs multiple times in the list. + #[allow(unused_mut)] + let (mut $var, i) = $var.quote_into_iter(); + let $has_iter = $has_iter | i; + }; +} + +#[macro_export] +#[doc(hidden)] +macro_rules! quote_bind_next_or_break { + ($var:ident) => { + let $var = match $var.next() { + Some(_x) => $crate::__private::RepInterp(_x), + None => break, + }; + }; +} + +// The obvious way to write this macro is as a tt muncher. This implementation +// does something more complex for two reasons. +// +// - With a tt muncher it's easy to hit Rust's built-in recursion_limit, which +// this implementation avoids because it isn't tail recursive. +// +// - Compile times for a tt muncher are quadratic relative to the length of +// the input. This implementation is linear, so it will be faster +// (potentially much faster) for big inputs. However, the constant factors +// of this implementation are higher than that of a tt muncher, so it is +// somewhat slower than a tt muncher if there are many invocations with +// short inputs. +// +// An invocation like this: +// +// quote_each_token!(_s a b c d e f g h i j); +// +// expands to this: +// +// quote_tokens_with_context!(_s +// (@ @ @ @ @ @ a b c d e f g h i j) +// (@ @ @ @ @ a b c d e f g h i j @) +// (@ @ @ @ a b c d e f g h i j @ @) +// (@ @ @ (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) @ @ @) +// (@ @ a b c d e f g h i j @ @ @ @) +// (@ a b c d e f g h i j @ @ @ @ @) +// (a b c d e f g h i j @ @ @ @ @ @) +// ); +// +// which gets transposed and expanded to this: +// +// quote_token_with_context!(_s @ @ @ @ @ @ a); +// quote_token_with_context!(_s @ @ @ @ @ a b); +// quote_token_with_context!(_s @ @ @ @ a b c); +// quote_token_with_context!(_s @ @ @ (a) b c d); +// quote_token_with_context!(_s @ @ a (b) c d e); +// quote_token_with_context!(_s @ a b (c) d e f); +// quote_token_with_context!(_s a b c (d) e f g); +// quote_token_with_context!(_s b c d (e) f g h); +// quote_token_with_context!(_s c d e (f) g h i); +// quote_token_with_context!(_s d e f (g) h i j); +// quote_token_with_context!(_s e f g (h) i j @); +// quote_token_with_context!(_s f g h (i) j @ @); +// quote_token_with_context!(_s g h i (j) @ @ @); +// quote_token_with_context!(_s h i j @ @ @ @); +// quote_token_with_context!(_s i j @ @ @ @ @); +// quote_token_with_context!(_s j @ @ @ @ @ @); +// +// Without having used muncher-style recursion, we get one invocation of +// quote_token_with_context for each original tt, with three tts of context on +// either side. This is enough for the longest possible interpolation form (a +// repetition with separator, as in `# (#var) , *`) to be fully represented with +// the first or last tt in the middle. +// +// The middle tt (surrounded by parentheses) is the tt being processed. +// +// - When it is a `#`, quote_token_with_context can do an interpolation. The +// interpolation kind will depend on the three subsequent tts. +// +// - When it is within a later part of an interpolation, it can be ignored +// because the interpolation has already been done. +// +// - When it is not part of an interpolation it can be pushed as a single +// token into the output. +// +// - When the middle token is an unparenthesized `@`, that call is one of the +// first 3 or last 3 calls of quote_token_with_context and does not +// correspond to one of the original input tokens, so turns into nothing. +#[macro_export] +#[doc(hidden)] +macro_rules! quote_each_token { + ($tokens:ident $($tts:tt)*) => { + $crate::quote_tokens_with_context!{$tokens + (@ @ @ @ @ @ $($tts)*) + (@ @ @ @ @ $($tts)* @) + (@ @ @ @ $($tts)* @ @) + (@ @ @ $(($tts))* @ @ @) + (@ @ $($tts)* @ @ @ @) + (@ $($tts)* @ @ @ @ @) + ($($tts)* @ @ @ @ @ @) + } + }; +} + +// See the explanation on quote_each_token. +#[macro_export] +#[doc(hidden)] +macro_rules! quote_each_token_spanned { + ($tokens:ident $span:ident $($tts:tt)*) => { + $crate::quote_tokens_with_context_spanned!{$tokens $span + (@ @ @ @ @ @ $($tts)*) + (@ @ @ @ @ $($tts)* @) + (@ @ @ @ $($tts)* @ @) + (@ @ @ $(($tts))* @ @ @) + (@ @ $($tts)* @ @ @ @) + (@ $($tts)* @ @ @ @ @) + ($($tts)* @ @ @ @ @ @) + } + }; +} + +// See the explanation on quote_each_token. +#[macro_export] +#[doc(hidden)] +macro_rules! quote_tokens_with_context { + ($tokens:ident + ($($b3:tt)*) ($($b2:tt)*) ($($b1:tt)*) + ($($curr:tt)*) + ($($a1:tt)*) ($($a2:tt)*) ($($a3:tt)*) + ) => { + $( + $crate::quote_token_with_context!{$tokens $b3 $b2 $b1 $curr $a1 $a2 $a3} + )* + }; +} + +// See the explanation on quote_each_token. +#[macro_export] +#[doc(hidden)] +macro_rules! quote_tokens_with_context_spanned { + ($tokens:ident $span:ident + ($($b3:tt)*) ($($b2:tt)*) ($($b1:tt)*) + ($($curr:tt)*) + ($($a1:tt)*) ($($a2:tt)*) ($($a3:tt)*) + ) => { + $( + $crate::quote_token_with_context_spanned!{$tokens $span $b3 $b2 $b1 $curr $a1 $a2 $a3} + )* + }; +} + +// See the explanation on quote_each_token. +#[macro_export] +#[doc(hidden)] +macro_rules! quote_token_with_context { + // Unparenthesized `@` indicates this call does not correspond to one of the + // original input tokens. Ignore it. + ($tokens:ident $b3:tt $b2:tt $b1:tt @ $a1:tt $a2:tt $a3:tt) => {}; + + // A repetition with no separator. + ($tokens:ident $b3:tt $b2:tt $b1:tt (#) ( $($inner:tt)* ) * $a3:tt) => {{ + use $crate::__private::ext::*; + let has_iter = $crate::__private::ThereIsNoIteratorInRepetition; + $crate::pounded_var_names!{quote_bind_into_iter!(has_iter) () $($inner)*} + let _: $crate::__private::HasIterator = has_iter; + // This is `while true` instead of `loop` because if there are no + // iterators used inside of this repetition then the body would not + // contain any `break`, so the compiler would emit unreachable code + // warnings on anything below the loop. We use has_iter to detect and + // fail to compile when there are no iterators, so here we just work + // around the unneeded extra warning. + while true { + $crate::pounded_var_names!{quote_bind_next_or_break!() () $($inner)*} + $crate::quote_each_token!{$tokens $($inner)*} + } + }}; + // ... and one step later. + ($tokens:ident $b3:tt $b2:tt # (( $($inner:tt)* )) * $a2:tt $a3:tt) => {}; + // ... and one step later. + ($tokens:ident $b3:tt # ( $($inner:tt)* ) (*) $a1:tt $a2:tt $a3:tt) => {}; + + // A repetition with separator. + ($tokens:ident $b3:tt $b2:tt $b1:tt (#) ( $($inner:tt)* ) $sep:tt *) => {{ + use $crate::__private::ext::*; + let mut _i = 0usize; + let has_iter = $crate::__private::ThereIsNoIteratorInRepetition; + $crate::pounded_var_names!{quote_bind_into_iter!(has_iter) () $($inner)*} + let _: $crate::__private::HasIterator = has_iter; + while true { + $crate::pounded_var_names!{quote_bind_next_or_break!() () $($inner)*} + if _i > 0 { + $crate::quote_token!{$sep $tokens} + } + _i += 1; + $crate::quote_each_token!{$tokens $($inner)*} + } + }}; + // ... and one step later. + ($tokens:ident $b3:tt $b2:tt # (( $($inner:tt)* )) $sep:tt * $a3:tt) => {}; + // ... and one step later. + ($tokens:ident $b3:tt # ( $($inner:tt)* ) ($sep:tt) * $a2:tt $a3:tt) => {}; + // (A special case for `#(var)**`, where the first `*` is treated as the + // repetition symbol and the second `*` is treated as an ordinary token.) + ($tokens:ident # ( $($inner:tt)* ) * (*) $a1:tt $a2:tt $a3:tt) => { + // https://github.com/dtolnay/quote/issues/130 + $crate::quote_token!{* $tokens} + }; + // ... and one step later. + ($tokens:ident # ( $($inner:tt)* ) $sep:tt (*) $a1:tt $a2:tt $a3:tt) => {}; + + // A non-repetition interpolation. + ($tokens:ident $b3:tt $b2:tt $b1:tt (#) $var:ident $a2:tt $a3:tt) => { + $crate::ToTokens::to_tokens(&$var, &mut $tokens); + }; + // ... and one step later. + ($tokens:ident $b3:tt $b2:tt # ($var:ident) $a1:tt $a2:tt $a3:tt) => {}; + + // An ordinary token, not part of any interpolation. + ($tokens:ident $b3:tt $b2:tt $b1:tt ($curr:tt) $a1:tt $a2:tt $a3:tt) => { + $crate::quote_token!{$curr $tokens} + }; +} + +// See the explanation on quote_each_token, and on the individual rules of +// quote_token_with_context. +#[macro_export] +#[doc(hidden)] +macro_rules! quote_token_with_context_spanned { + ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt @ $a1:tt $a2:tt $a3:tt) => {}; + + ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt (#) ( $($inner:tt)* ) * $a3:tt) => {{ + use $crate::__private::ext::*; + let has_iter = $crate::__private::ThereIsNoIteratorInRepetition; + $crate::pounded_var_names!{quote_bind_into_iter!(has_iter) () $($inner)*} + let _: $crate::__private::HasIterator = has_iter; + while true { + $crate::pounded_var_names!{quote_bind_next_or_break!() () $($inner)*} + $crate::quote_each_token_spanned!{$tokens $span $($inner)*} + } + }}; + ($tokens:ident $span:ident $b3:tt $b2:tt # (( $($inner:tt)* )) * $a2:tt $a3:tt) => {}; + ($tokens:ident $span:ident $b3:tt # ( $($inner:tt)* ) (*) $a1:tt $a2:tt $a3:tt) => {}; + + ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt (#) ( $($inner:tt)* ) $sep:tt *) => {{ + use $crate::__private::ext::*; + let mut _i = 0usize; + let has_iter = $crate::__private::ThereIsNoIteratorInRepetition; + $crate::pounded_var_names!{quote_bind_into_iter!(has_iter) () $($inner)*} + let _: $crate::__private::HasIterator = has_iter; + while true { + $crate::pounded_var_names!{quote_bind_next_or_break!() () $($inner)*} + if _i > 0 { + $crate::quote_token_spanned!{$sep $tokens $span} + } + _i += 1; + $crate::quote_each_token_spanned!{$tokens $span $($inner)*} + } + }}; + ($tokens:ident $span:ident $b3:tt $b2:tt # (( $($inner:tt)* )) $sep:tt * $a3:tt) => {}; + ($tokens:ident $span:ident $b3:tt # ( $($inner:tt)* ) ($sep:tt) * $a2:tt $a3:tt) => {}; + ($tokens:ident $span:ident # ( $($inner:tt)* ) * (*) $a1:tt $a2:tt $a3:tt) => { + // https://github.com/dtolnay/quote/issues/130 + $crate::quote_token_spanned!{* $tokens $span} + }; + ($tokens:ident $span:ident # ( $($inner:tt)* ) $sep:tt (*) $a1:tt $a2:tt $a3:tt) => {}; + + ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt (#) $var:ident $a2:tt $a3:tt) => { + $crate::ToTokens::to_tokens(&$var, &mut $tokens); + }; + ($tokens:ident $span:ident $b3:tt $b2:tt # ($var:ident) $a1:tt $a2:tt $a3:tt) => {}; + + ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt ($curr:tt) $a1:tt $a2:tt $a3:tt) => { + $crate::quote_token_spanned!{$curr $tokens $span} + }; +} + +// These rules are ordered by approximate token frequency, at least for the +// first 10 or so, to improve compile times. Having `ident` first is by far the +// most important because it's typically 2-3x more common than the next most +// common token. +// +// Separately, we put the token being matched in the very front so that failing +// rules may fail to match as quickly as possible. +#[macro_export] +#[doc(hidden)] +macro_rules! quote_token { + ($ident:ident $tokens:ident) => { + $crate::__private::push_ident(&mut $tokens, stringify!($ident)); + }; + + (:: $tokens:ident) => { + $crate::__private::push_colon2(&mut $tokens); + }; + + (( $($inner:tt)* ) $tokens:ident) => { + $crate::__private::push_group( + &mut $tokens, + $crate::__private::Delimiter::Parenthesis, + $crate::quote!($($inner)*), + ); + }; + + ([ $($inner:tt)* ] $tokens:ident) => { + $crate::__private::push_group( + &mut $tokens, + $crate::__private::Delimiter::Bracket, + $crate::quote!($($inner)*), + ); + }; + + ({ $($inner:tt)* } $tokens:ident) => { + $crate::__private::push_group( + &mut $tokens, + $crate::__private::Delimiter::Brace, + $crate::quote!($($inner)*), + ); + }; + + (# $tokens:ident) => { + $crate::__private::push_pound(&mut $tokens); + }; + + (, $tokens:ident) => { + $crate::__private::push_comma(&mut $tokens); + }; + + (. $tokens:ident) => { + $crate::__private::push_dot(&mut $tokens); + }; + + (; $tokens:ident) => { + $crate::__private::push_semi(&mut $tokens); + }; + + (: $tokens:ident) => { + $crate::__private::push_colon(&mut $tokens); + }; + + (+ $tokens:ident) => { + $crate::__private::push_add(&mut $tokens); + }; + + (+= $tokens:ident) => { + $crate::__private::push_add_eq(&mut $tokens); + }; + + (& $tokens:ident) => { + $crate::__private::push_and(&mut $tokens); + }; + + (&& $tokens:ident) => { + $crate::__private::push_and_and(&mut $tokens); + }; + + (&= $tokens:ident) => { + $crate::__private::push_and_eq(&mut $tokens); + }; + + (@ $tokens:ident) => { + $crate::__private::push_at(&mut $tokens); + }; + + (! $tokens:ident) => { + $crate::__private::push_bang(&mut $tokens); + }; + + (^ $tokens:ident) => { + $crate::__private::push_caret(&mut $tokens); + }; + + (^= $tokens:ident) => { + $crate::__private::push_caret_eq(&mut $tokens); + }; + + (/ $tokens:ident) => { + $crate::__private::push_div(&mut $tokens); + }; + + (/= $tokens:ident) => { + $crate::__private::push_div_eq(&mut $tokens); + }; + + (.. $tokens:ident) => { + $crate::__private::push_dot2(&mut $tokens); + }; + + (... $tokens:ident) => { + $crate::__private::push_dot3(&mut $tokens); + }; + + (..= $tokens:ident) => { + $crate::__private::push_dot_dot_eq(&mut $tokens); + }; + + (= $tokens:ident) => { + $crate::__private::push_eq(&mut $tokens); + }; + + (== $tokens:ident) => { + $crate::__private::push_eq_eq(&mut $tokens); + }; + + (>= $tokens:ident) => { + $crate::__private::push_ge(&mut $tokens); + }; + + (> $tokens:ident) => { + $crate::__private::push_gt(&mut $tokens); + }; + + (<= $tokens:ident) => { + $crate::__private::push_le(&mut $tokens); + }; + + (< $tokens:ident) => { + $crate::__private::push_lt(&mut $tokens); + }; + + (*= $tokens:ident) => { + $crate::__private::push_mul_eq(&mut $tokens); + }; + + (!= $tokens:ident) => { + $crate::__private::push_ne(&mut $tokens); + }; + + (| $tokens:ident) => { + $crate::__private::push_or(&mut $tokens); + }; + + (|= $tokens:ident) => { + $crate::__private::push_or_eq(&mut $tokens); + }; + + (|| $tokens:ident) => { + $crate::__private::push_or_or(&mut $tokens); + }; + + (? $tokens:ident) => { + $crate::__private::push_question(&mut $tokens); + }; + + (-> $tokens:ident) => { + $crate::__private::push_rarrow(&mut $tokens); + }; + + (<- $tokens:ident) => { + $crate::__private::push_larrow(&mut $tokens); + }; + + (% $tokens:ident) => { + $crate::__private::push_rem(&mut $tokens); + }; + + (%= $tokens:ident) => { + $crate::__private::push_rem_eq(&mut $tokens); + }; + + (=> $tokens:ident) => { + $crate::__private::push_fat_arrow(&mut $tokens); + }; + + (<< $tokens:ident) => { + $crate::__private::push_shl(&mut $tokens); + }; + + (<<= $tokens:ident) => { + $crate::__private::push_shl_eq(&mut $tokens); + }; + + (>> $tokens:ident) => { + $crate::__private::push_shr(&mut $tokens); + }; + + (>>= $tokens:ident) => { + $crate::__private::push_shr_eq(&mut $tokens); + }; + + (* $tokens:ident) => { + $crate::__private::push_star(&mut $tokens); + }; + + (- $tokens:ident) => { + $crate::__private::push_sub(&mut $tokens); + }; + + (-= $tokens:ident) => { + $crate::__private::push_sub_eq(&mut $tokens); + }; + + ($lifetime:lifetime $tokens:ident) => { + $crate::__private::push_lifetime(&mut $tokens, stringify!($lifetime)); + }; + + (_ $tokens:ident) => { + $crate::__private::push_underscore(&mut $tokens); + }; + + ($other:tt $tokens:ident) => { + $crate::__private::parse(&mut $tokens, stringify!($other)); + }; +} + +// See the comment above `quote_token!` about the rule ordering. +#[macro_export] +#[doc(hidden)] +macro_rules! quote_token_spanned { + ($ident:ident $tokens:ident $span:ident) => { + $crate::__private::push_ident_spanned(&mut $tokens, $span, stringify!($ident)); + }; + + (:: $tokens:ident $span:ident) => { + $crate::__private::push_colon2_spanned(&mut $tokens, $span); + }; + + (( $($inner:tt)* ) $tokens:ident $span:ident) => { + $crate::__private::push_group_spanned( + &mut $tokens, + $span, + $crate::__private::Delimiter::Parenthesis, + $crate::quote_spanned!($span=> $($inner)*), + ); + }; + + ([ $($inner:tt)* ] $tokens:ident $span:ident) => { + $crate::__private::push_group_spanned( + &mut $tokens, + $span, + $crate::__private::Delimiter::Bracket, + $crate::quote_spanned!($span=> $($inner)*), + ); + }; + + ({ $($inner:tt)* } $tokens:ident $span:ident) => { + $crate::__private::push_group_spanned( + &mut $tokens, + $span, + $crate::__private::Delimiter::Brace, + $crate::quote_spanned!($span=> $($inner)*), + ); + }; + + (# $tokens:ident $span:ident) => { + $crate::__private::push_pound_spanned(&mut $tokens, $span); + }; + + (, $tokens:ident $span:ident) => { + $crate::__private::push_comma_spanned(&mut $tokens, $span); + }; + + (. $tokens:ident $span:ident) => { + $crate::__private::push_dot_spanned(&mut $tokens, $span); + }; + + (; $tokens:ident $span:ident) => { + $crate::__private::push_semi_spanned(&mut $tokens, $span); + }; + + (: $tokens:ident $span:ident) => { + $crate::__private::push_colon_spanned(&mut $tokens, $span); + }; + + (+ $tokens:ident $span:ident) => { + $crate::__private::push_add_spanned(&mut $tokens, $span); + }; + + (+= $tokens:ident $span:ident) => { + $crate::__private::push_add_eq_spanned(&mut $tokens, $span); + }; + + (& $tokens:ident $span:ident) => { + $crate::__private::push_and_spanned(&mut $tokens, $span); + }; + + (&& $tokens:ident $span:ident) => { + $crate::__private::push_and_and_spanned(&mut $tokens, $span); + }; + + (&= $tokens:ident $span:ident) => { + $crate::__private::push_and_eq_spanned(&mut $tokens, $span); + }; + + (@ $tokens:ident $span:ident) => { + $crate::__private::push_at_spanned(&mut $tokens, $span); + }; + + (! $tokens:ident $span:ident) => { + $crate::__private::push_bang_spanned(&mut $tokens, $span); + }; + + (^ $tokens:ident $span:ident) => { + $crate::__private::push_caret_spanned(&mut $tokens, $span); + }; + + (^= $tokens:ident $span:ident) => { + $crate::__private::push_caret_eq_spanned(&mut $tokens, $span); + }; + + (/ $tokens:ident $span:ident) => { + $crate::__private::push_div_spanned(&mut $tokens, $span); + }; + + (/= $tokens:ident $span:ident) => { + $crate::__private::push_div_eq_spanned(&mut $tokens, $span); + }; + + (.. $tokens:ident $span:ident) => { + $crate::__private::push_dot2_spanned(&mut $tokens, $span); + }; + + (... $tokens:ident $span:ident) => { + $crate::__private::push_dot3_spanned(&mut $tokens, $span); + }; + + (..= $tokens:ident $span:ident) => { + $crate::__private::push_dot_dot_eq_spanned(&mut $tokens, $span); + }; + + (= $tokens:ident $span:ident) => { + $crate::__private::push_eq_spanned(&mut $tokens, $span); + }; + + (== $tokens:ident $span:ident) => { + $crate::__private::push_eq_eq_spanned(&mut $tokens, $span); + }; + + (>= $tokens:ident $span:ident) => { + $crate::__private::push_ge_spanned(&mut $tokens, $span); + }; + + (> $tokens:ident $span:ident) => { + $crate::__private::push_gt_spanned(&mut $tokens, $span); + }; + + (<= $tokens:ident $span:ident) => { + $crate::__private::push_le_spanned(&mut $tokens, $span); + }; + + (< $tokens:ident $span:ident) => { + $crate::__private::push_lt_spanned(&mut $tokens, $span); + }; + + (*= $tokens:ident $span:ident) => { + $crate::__private::push_mul_eq_spanned(&mut $tokens, $span); + }; + + (!= $tokens:ident $span:ident) => { + $crate::__private::push_ne_spanned(&mut $tokens, $span); + }; + + (| $tokens:ident $span:ident) => { + $crate::__private::push_or_spanned(&mut $tokens, $span); + }; + + (|= $tokens:ident $span:ident) => { + $crate::__private::push_or_eq_spanned(&mut $tokens, $span); + }; + + (|| $tokens:ident $span:ident) => { + $crate::__private::push_or_or_spanned(&mut $tokens, $span); + }; + + (? $tokens:ident $span:ident) => { + $crate::__private::push_question_spanned(&mut $tokens, $span); + }; + + (-> $tokens:ident $span:ident) => { + $crate::__private::push_rarrow_spanned(&mut $tokens, $span); + }; + + (<- $tokens:ident $span:ident) => { + $crate::__private::push_larrow_spanned(&mut $tokens, $span); + }; + + (% $tokens:ident $span:ident) => { + $crate::__private::push_rem_spanned(&mut $tokens, $span); + }; + + (%= $tokens:ident $span:ident) => { + $crate::__private::push_rem_eq_spanned(&mut $tokens, $span); + }; + + (=> $tokens:ident $span:ident) => { + $crate::__private::push_fat_arrow_spanned(&mut $tokens, $span); + }; + + (<< $tokens:ident $span:ident) => { + $crate::__private::push_shl_spanned(&mut $tokens, $span); + }; + + (<<= $tokens:ident $span:ident) => { + $crate::__private::push_shl_eq_spanned(&mut $tokens, $span); + }; + + (>> $tokens:ident $span:ident) => { + $crate::__private::push_shr_spanned(&mut $tokens, $span); + }; + + (>>= $tokens:ident $span:ident) => { + $crate::__private::push_shr_eq_spanned(&mut $tokens, $span); + }; + + (* $tokens:ident $span:ident) => { + $crate::__private::push_star_spanned(&mut $tokens, $span); + }; + + (- $tokens:ident $span:ident) => { + $crate::__private::push_sub_spanned(&mut $tokens, $span); + }; + + (-= $tokens:ident $span:ident) => { + $crate::__private::push_sub_eq_spanned(&mut $tokens, $span); + }; + + ($lifetime:lifetime $tokens:ident $span:ident) => { + $crate::__private::push_lifetime_spanned(&mut $tokens, $span, stringify!($lifetime)); + }; + + (_ $tokens:ident $span:ident) => { + $crate::__private::push_underscore_spanned(&mut $tokens, $span); + }; + + ($other:tt $tokens:ident $span:ident) => { + $crate::__private::parse_spanned(&mut $tokens, $span, stringify!($other)); + }; +} diff --git a/rust/quote/runtime.rs b/rust/quote/runtime.rs new file mode 100644 index 000000000..09a94f5dd --- /dev/null +++ b/rust/quote/runtime.rs @@ -0,0 +1,494 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use self::get_span::{GetSpan, GetSpanBase, GetSpanInner}; +use crate::{IdentFragment, ToTokens, TokenStreamExt}; +use core::fmt; +use core::iter; +use core::ops::BitOr; +use proc_macro2::{Group, Ident, Punct, Spacing, TokenTree}; + +#[doc(hidden)] +pub use alloc::format; +#[doc(hidden)] +pub use core::option::Option; + +#[doc(hidden)] +pub type Delimiter = proc_macro2::Delimiter; +#[doc(hidden)] +pub type Span = proc_macro2::Span; +#[doc(hidden)] +pub type TokenStream = proc_macro2::TokenStream; + +#[doc(hidden)] +pub struct HasIterator; // True +#[doc(hidden)] +pub struct ThereIsNoIteratorInRepetition; // False + +impl BitOr for ThereIsNoIteratorInRepetition { + type Output = ThereIsNoIteratorInRepetition; + fn bitor(self, _rhs: ThereIsNoIteratorInRepetition) -> ThereIsNoIteratorInRepetition { + ThereIsNoIteratorInRepetition + } +} + +impl BitOr for HasIterator { + type Output = HasIterator; + fn bitor(self, _rhs: ThereIsNoIteratorInRepetition) -> HasIterator { + HasIterator + } +} + +impl BitOr for ThereIsNoIteratorInRepetition { + type Output = HasIterator; + fn bitor(self, _rhs: HasIterator) -> HasIterator { + HasIterator + } +} + +impl BitOr for HasIterator { + type Output = HasIterator; + fn bitor(self, _rhs: HasIterator) -> HasIterator { + HasIterator + } +} + +/// Extension traits used by the implementation of `quote!`. These are defined +/// in separate traits, rather than as a single trait due to ambiguity issues. +/// +/// These traits expose a `quote_into_iter` method which should allow calling +/// whichever impl happens to be applicable. Calling that method repeatedly on +/// the returned value should be idempotent. +#[doc(hidden)] +pub mod ext { + use super::RepInterp; + use super::{HasIterator as HasIter, ThereIsNoIteratorInRepetition as DoesNotHaveIter}; + use crate::ToTokens; + use alloc::collections::btree_set::{self, BTreeSet}; + use core::slice; + + /// Extension trait providing the `quote_into_iter` method on iterators. + #[doc(hidden)] + pub trait RepIteratorExt: Iterator + Sized { + fn quote_into_iter(self) -> (Self, HasIter) { + (self, HasIter) + } + } + + impl RepIteratorExt for T {} + + /// Extension trait providing the `quote_into_iter` method for + /// non-iterable types. These types interpolate the same value in each + /// iteration of the repetition. + #[doc(hidden)] + pub trait RepToTokensExt { + /// Pretend to be an iterator for the purposes of `quote_into_iter`. + /// This allows repeated calls to `quote_into_iter` to continue + /// correctly returning DoesNotHaveIter. + fn next(&self) -> Option<&Self> { + Some(self) + } + + fn quote_into_iter(&self) -> (&Self, DoesNotHaveIter) { + (self, DoesNotHaveIter) + } + } + + impl RepToTokensExt for T {} + + /// Extension trait providing the `quote_into_iter` method for types that + /// can be referenced as an iterator. + #[doc(hidden)] + pub trait RepAsIteratorExt<'q> { + type Iter: Iterator; + + fn quote_into_iter(&'q self) -> (Self::Iter, HasIter); + } + + impl<'q, T: RepAsIteratorExt<'q> + ?Sized> RepAsIteratorExt<'q> for &T { + type Iter = T::Iter; + + fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) { + ::quote_into_iter(*self) + } + } + + impl<'q, T: RepAsIteratorExt<'q> + ?Sized> RepAsIteratorExt<'q> for &mut T { + type Iter = T::Iter; + + fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) { + ::quote_into_iter(*self) + } + } + + impl<'q, T: 'q> RepAsIteratorExt<'q> for [T] { + type Iter = slice::Iter<'q, T>; + + fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) { + (self.iter(), HasIter) + } + } + + impl<'q, T: 'q, const N: usize> RepAsIteratorExt<'q> for [T; N] { + type Iter = slice::Iter<'q, T>; + + fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) { + (self.iter(), HasIter) + } + } + + impl<'q, T: 'q> RepAsIteratorExt<'q> for Vec { + type Iter = slice::Iter<'q, T>; + + fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) { + (self.iter(), HasIter) + } + } + + impl<'q, T: 'q> RepAsIteratorExt<'q> for BTreeSet { + type Iter = btree_set::Iter<'q, T>; + + fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) { + (self.iter(), HasIter) + } + } + + impl<'q, T: RepAsIteratorExt<'q>> RepAsIteratorExt<'q> for RepInterp { + type Iter = T::Iter; + + fn quote_into_iter(&'q self) -> (Self::Iter, HasIter) { + self.0.quote_into_iter() + } + } +} + +// Helper type used within interpolations to allow for repeated binding names. +// Implements the relevant traits, and exports a dummy `next()` method. +#[derive(Copy, Clone)] +#[doc(hidden)] +pub struct RepInterp(pub T); + +impl RepInterp { + // This method is intended to look like `Iterator::next`, and is called when + // a name is bound multiple times, as the previous binding will shadow the + // original `Iterator` object. This allows us to avoid advancing the + // iterator multiple times per iteration. + pub fn next(self) -> Option { + Some(self.0) + } +} + +impl Iterator for RepInterp { + type Item = T::Item; + + fn next(&mut self) -> Option { + self.0.next() + } +} + +impl ToTokens for RepInterp { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.0.to_tokens(tokens); + } +} + +#[doc(hidden)] +#[inline] +pub fn get_span(span: T) -> GetSpan { + GetSpan(GetSpanInner(GetSpanBase(span))) +} + +mod get_span { + use core::ops::Deref; + use proc_macro2::extra::DelimSpan; + use proc_macro2::Span; + + pub struct GetSpan(pub(crate) GetSpanInner); + + pub struct GetSpanInner(pub(crate) GetSpanBase); + + pub struct GetSpanBase(pub(crate) T); + + impl GetSpan { + #[inline] + pub fn __into_span(self) -> Span { + ((self.0).0).0 + } + } + + impl GetSpanInner { + #[inline] + pub fn __into_span(&self) -> Span { + (self.0).0.join() + } + } + + impl GetSpanBase { + #[allow(clippy::unused_self)] + pub fn __into_span(&self) -> T { + unreachable!() + } + } + + impl Deref for GetSpan { + type Target = GetSpanInner; + + #[inline] + fn deref(&self) -> &Self::Target { + &self.0 + } + } + + impl Deref for GetSpanInner { + type Target = GetSpanBase; + + #[inline] + fn deref(&self) -> &Self::Target { + &self.0 + } + } +} + +#[doc(hidden)] +pub fn push_group(tokens: &mut TokenStream, delimiter: Delimiter, inner: TokenStream) { + tokens.append(Group::new(delimiter, inner)); +} + +#[doc(hidden)] +pub fn push_group_spanned( + tokens: &mut TokenStream, + span: Span, + delimiter: Delimiter, + inner: TokenStream, +) { + let mut g = Group::new(delimiter, inner); + g.set_span(span); + tokens.append(g); +} + +#[doc(hidden)] +pub fn parse(tokens: &mut TokenStream, s: &str) { + let s: TokenStream = s.parse().expect("invalid token stream"); + tokens.extend(iter::once(s)); +} + +#[doc(hidden)] +pub fn parse_spanned(tokens: &mut TokenStream, span: Span, s: &str) { + let s: TokenStream = s.parse().expect("invalid token stream"); + tokens.extend(s.into_iter().map(|t| respan_token_tree(t, span))); +} + +// Token tree with every span replaced by the given one. +fn respan_token_tree(mut token: TokenTree, span: Span) -> TokenTree { + match &mut token { + TokenTree::Group(g) => { + let stream = g + .stream() + .into_iter() + .map(|token| respan_token_tree(token, span)) + .collect(); + *g = Group::new(g.delimiter(), stream); + g.set_span(span); + } + other => other.set_span(span), + } + token +} + +#[doc(hidden)] +pub fn push_ident(tokens: &mut TokenStream, s: &str) { + let span = Span::call_site(); + push_ident_spanned(tokens, span, s); +} + +#[doc(hidden)] +pub fn push_ident_spanned(tokens: &mut TokenStream, span: Span, s: &str) { + tokens.append(ident_maybe_raw(s, span)); +} + +#[doc(hidden)] +pub fn push_lifetime(tokens: &mut TokenStream, lifetime: &str) { + tokens.extend([ + TokenTree::Punct(Punct::new('\'', Spacing::Joint)), + TokenTree::Ident(Ident::new(&lifetime[1..], Span::call_site())), + ]); +} + +#[doc(hidden)] +pub fn push_lifetime_spanned(tokens: &mut TokenStream, span: Span, lifetime: &str) { + tokens.extend([ + TokenTree::Punct({ + let mut apostrophe = Punct::new('\'', Spacing::Joint); + apostrophe.set_span(span); + apostrophe + }), + TokenTree::Ident(Ident::new(&lifetime[1..], span)), + ]); +} + +macro_rules! push_punct { + ($name:ident $spanned:ident $char1:tt) => { + #[doc(hidden)] + pub fn $name(tokens: &mut TokenStream) { + tokens.append(Punct::new($char1, Spacing::Alone)); + } + #[doc(hidden)] + pub fn $spanned(tokens: &mut TokenStream, span: Span) { + let mut punct = Punct::new($char1, Spacing::Alone); + punct.set_span(span); + tokens.append(punct); + } + }; + ($name:ident $spanned:ident $char1:tt $char2:tt) => { + #[doc(hidden)] + pub fn $name(tokens: &mut TokenStream) { + tokens.append(Punct::new($char1, Spacing::Joint)); + tokens.append(Punct::new($char2, Spacing::Alone)); + } + #[doc(hidden)] + pub fn $spanned(tokens: &mut TokenStream, span: Span) { + let mut punct = Punct::new($char1, Spacing::Joint); + punct.set_span(span); + tokens.append(punct); + let mut punct = Punct::new($char2, Spacing::Alone); + punct.set_span(span); + tokens.append(punct); + } + }; + ($name:ident $spanned:ident $char1:tt $char2:tt $char3:tt) => { + #[doc(hidden)] + pub fn $name(tokens: &mut TokenStream) { + tokens.append(Punct::new($char1, Spacing::Joint)); + tokens.append(Punct::new($char2, Spacing::Joint)); + tokens.append(Punct::new($char3, Spacing::Alone)); + } + #[doc(hidden)] + pub fn $spanned(tokens: &mut TokenStream, span: Span) { + let mut punct = Punct::new($char1, Spacing::Joint); + punct.set_span(span); + tokens.append(punct); + let mut punct = Punct::new($char2, Spacing::Joint); + punct.set_span(span); + tokens.append(punct); + let mut punct = Punct::new($char3, Spacing::Alone); + punct.set_span(span); + tokens.append(punct); + } + }; +} + +push_punct!(push_add push_add_spanned '+'); +push_punct!(push_add_eq push_add_eq_spanned '+' '='); +push_punct!(push_and push_and_spanned '&'); +push_punct!(push_and_and push_and_and_spanned '&' '&'); +push_punct!(push_and_eq push_and_eq_spanned '&' '='); +push_punct!(push_at push_at_spanned '@'); +push_punct!(push_bang push_bang_spanned '!'); +push_punct!(push_caret push_caret_spanned '^'); +push_punct!(push_caret_eq push_caret_eq_spanned '^' '='); +push_punct!(push_colon push_colon_spanned ':'); +push_punct!(push_colon2 push_colon2_spanned ':' ':'); +push_punct!(push_comma push_comma_spanned ','); +push_punct!(push_div push_div_spanned '/'); +push_punct!(push_div_eq push_div_eq_spanned '/' '='); +push_punct!(push_dot push_dot_spanned '.'); +push_punct!(push_dot2 push_dot2_spanned '.' '.'); +push_punct!(push_dot3 push_dot3_spanned '.' '.' '.'); +push_punct!(push_dot_dot_eq push_dot_dot_eq_spanned '.' '.' '='); +push_punct!(push_eq push_eq_spanned '='); +push_punct!(push_eq_eq push_eq_eq_spanned '=' '='); +push_punct!(push_ge push_ge_spanned '>' '='); +push_punct!(push_gt push_gt_spanned '>'); +push_punct!(push_le push_le_spanned '<' '='); +push_punct!(push_lt push_lt_spanned '<'); +push_punct!(push_mul_eq push_mul_eq_spanned '*' '='); +push_punct!(push_ne push_ne_spanned '!' '='); +push_punct!(push_or push_or_spanned '|'); +push_punct!(push_or_eq push_or_eq_spanned '|' '='); +push_punct!(push_or_or push_or_or_spanned '|' '|'); +push_punct!(push_pound push_pound_spanned '#'); +push_punct!(push_question push_question_spanned '?'); +push_punct!(push_rarrow push_rarrow_spanned '-' '>'); +push_punct!(push_larrow push_larrow_spanned '<' '-'); +push_punct!(push_rem push_rem_spanned '%'); +push_punct!(push_rem_eq push_rem_eq_spanned '%' '='); +push_punct!(push_fat_arrow push_fat_arrow_spanned '=' '>'); +push_punct!(push_semi push_semi_spanned ';'); +push_punct!(push_shl push_shl_spanned '<' '<'); +push_punct!(push_shl_eq push_shl_eq_spanned '<' '<' '='); +push_punct!(push_shr push_shr_spanned '>' '>'); +push_punct!(push_shr_eq push_shr_eq_spanned '>' '>' '='); +push_punct!(push_star push_star_spanned '*'); +push_punct!(push_sub push_sub_spanned '-'); +push_punct!(push_sub_eq push_sub_eq_spanned '-' '='); + +#[doc(hidden)] +pub fn push_underscore(tokens: &mut TokenStream) { + push_underscore_spanned(tokens, Span::call_site()); +} + +#[doc(hidden)] +pub fn push_underscore_spanned(tokens: &mut TokenStream, span: Span) { + tokens.append(Ident::new("_", span)); +} + +// Helper method for constructing identifiers from the `format_ident!` macro, +// handling `r#` prefixes. +#[doc(hidden)] +pub fn mk_ident(id: &str, span: Option) -> Ident { + let span = span.unwrap_or_else(Span::call_site); + ident_maybe_raw(id, span) +} + +fn ident_maybe_raw(id: &str, span: Span) -> Ident { + if let Some(id) = id.strip_prefix("r#") { + Ident::new_raw(id, span) + } else { + Ident::new(id, span) + } +} + +// Adapts from `IdentFragment` to `fmt::Display` for use by the `format_ident!` +// macro, and exposes span information from these fragments. +// +// This struct also has forwarding implementations of the formatting traits +// `Octal`, `LowerHex`, `UpperHex`, and `Binary` to allow for their use within +// `format_ident!`. +#[derive(Copy, Clone)] +#[doc(hidden)] +pub struct IdentFragmentAdapter(pub T); + +impl IdentFragmentAdapter { + pub fn span(&self) -> Option { + self.0.span() + } +} + +impl fmt::Display for IdentFragmentAdapter { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + IdentFragment::fmt(&self.0, f) + } +} + +impl fmt::Octal for IdentFragmentAdapter { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::Octal::fmt(&self.0, f) + } +} + +impl fmt::LowerHex for IdentFragmentAdapter { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::LowerHex::fmt(&self.0, f) + } +} + +impl fmt::UpperHex for IdentFragmentAdapter { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::UpperHex::fmt(&self.0, f) + } +} + +impl fmt::Binary for IdentFragmentAdapter { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + fmt::Binary::fmt(&self.0, f) + } +} diff --git a/rust/quote/spanned.rs b/rust/quote/spanned.rs new file mode 100644 index 000000000..54ce9177f --- /dev/null +++ b/rust/quote/spanned.rs @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use crate::ToTokens; +use proc_macro2::extra::DelimSpan; +use proc_macro2::{Span, TokenStream}; + +// Not public API other than via the syn crate. Use syn::spanned::Spanned. +pub trait Spanned: private::Sealed { + fn __span(&self) -> Span; +} + +impl Spanned for Span { + fn __span(&self) -> Span { + *self + } +} + +impl Spanned for DelimSpan { + fn __span(&self) -> Span { + self.join() + } +} + +impl Spanned for T { + fn __span(&self) -> Span { + join_spans(self.into_token_stream()) + } +} + +fn join_spans(tokens: TokenStream) -> Span { + let mut iter = tokens.into_iter().map(|tt| tt.span()); + + let first = match iter.next() { + Some(span) => span, + None => return Span::call_site(), + }; + + iter.fold(None, |_prev, next| Some(next)) + .and_then(|last| first.join(last)) + .unwrap_or(first) +} + +mod private { + use crate::ToTokens; + use proc_macro2::extra::DelimSpan; + use proc_macro2::Span; + + pub trait Sealed {} + impl Sealed for Span {} + impl Sealed for DelimSpan {} + impl Sealed for T {} +} diff --git a/rust/quote/to_tokens.rs b/rust/quote/to_tokens.rs new file mode 100644 index 000000000..1af1089e1 --- /dev/null +++ b/rust/quote/to_tokens.rs @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use super::TokenStreamExt; +use alloc::borrow::Cow; +use alloc::rc::Rc; +use core::iter; +use proc_macro2::{Group, Ident, Literal, Punct, Span, TokenStream, TokenTree}; +use std::ffi::{CStr, CString}; + +/// Types that can be interpolated inside a `quote!` invocation. +pub trait ToTokens { + /// Write `self` to the given `TokenStream`. + /// + /// The token append methods provided by the [`TokenStreamExt`] extension + /// trait may be useful for implementing `ToTokens`. + /// + /// # Example + /// + /// Example implementation for a struct representing Rust paths like + /// `std::cmp::PartialEq`: + /// + /// ``` + /// use proc_macro2::{TokenTree, Spacing, Span, Punct, TokenStream}; + /// use quote::{TokenStreamExt, ToTokens}; + /// + /// pub struct Path { + /// pub global: bool, + /// pub segments: Vec, + /// } + /// + /// impl ToTokens for Path { + /// fn to_tokens(&self, tokens: &mut TokenStream) { + /// for (i, segment) in self.segments.iter().enumerate() { + /// if i > 0 || self.global { + /// // Double colon `::` + /// tokens.append(Punct::new(':', Spacing::Joint)); + /// tokens.append(Punct::new(':', Spacing::Alone)); + /// } + /// segment.to_tokens(tokens); + /// } + /// } + /// } + /// # + /// # pub struct PathSegment; + /// # + /// # impl ToTokens for PathSegment { + /// # fn to_tokens(&self, tokens: &mut TokenStream) { + /// # unimplemented!() + /// # } + /// # } + /// ``` + fn to_tokens(&self, tokens: &mut TokenStream); + + /// Convert `self` directly into a `TokenStream` object. + /// + /// This method is implicitly implemented using `to_tokens`, and acts as a + /// convenience method for consumers of the `ToTokens` trait. + fn to_token_stream(&self) -> TokenStream { + let mut tokens = TokenStream::new(); + self.to_tokens(&mut tokens); + tokens + } + + /// Convert `self` directly into a `TokenStream` object. + /// + /// This method is implicitly implemented using `to_tokens`, and acts as a + /// convenience method for consumers of the `ToTokens` trait. + fn into_token_stream(self) -> TokenStream + where + Self: Sized, + { + self.to_token_stream() + } +} + +impl ToTokens for &T { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl ToTokens for &mut T { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl<'a, T: ?Sized + ToOwned + ToTokens> ToTokens for Cow<'a, T> { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl ToTokens for Box { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl ToTokens for Rc { + fn to_tokens(&self, tokens: &mut TokenStream) { + (**self).to_tokens(tokens); + } +} + +impl ToTokens for Option { + fn to_tokens(&self, tokens: &mut TokenStream) { + if let Some(t) = self { + t.to_tokens(tokens); + } + } +} + +impl ToTokens for str { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::string(self)); + } +} + +impl ToTokens for String { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.as_str().to_tokens(tokens); + } +} + +impl ToTokens for i8 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::i8_suffixed(*self)); + } +} + +impl ToTokens for i16 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::i16_suffixed(*self)); + } +} + +impl ToTokens for i32 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::i32_suffixed(*self)); + } +} + +impl ToTokens for i64 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::i64_suffixed(*self)); + } +} + +impl ToTokens for i128 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::i128_suffixed(*self)); + } +} + +impl ToTokens for isize { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::isize_suffixed(*self)); + } +} + +impl ToTokens for u8 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::u8_suffixed(*self)); + } +} + +impl ToTokens for u16 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::u16_suffixed(*self)); + } +} + +impl ToTokens for u32 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::u32_suffixed(*self)); + } +} + +impl ToTokens for u64 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::u64_suffixed(*self)); + } +} + +impl ToTokens for u128 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::u128_suffixed(*self)); + } +} + +impl ToTokens for usize { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::usize_suffixed(*self)); + } +} + +impl ToTokens for f32 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::f32_suffixed(*self)); + } +} + +impl ToTokens for f64 { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::f64_suffixed(*self)); + } +} + +impl ToTokens for char { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::character(*self)); + } +} + +impl ToTokens for bool { + fn to_tokens(&self, tokens: &mut TokenStream) { + let word = if *self { "true" } else { "false" }; + tokens.append(Ident::new(word, Span::call_site())); + } +} + +impl ToTokens for CStr { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::c_string(self)); + } +} + +impl ToTokens for CString { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(Literal::c_string(self)); + } +} + +impl ToTokens for Group { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for Ident { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for Punct { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for Literal { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for TokenTree { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append(self.clone()); + } +} + +impl ToTokens for TokenStream { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.extend(iter::once(self.clone())); + } + + fn into_token_stream(self) -> TokenStream { + self + } +} -- cgit v1.3.1