rust/src/test/ui/proc-macro/auxiliary/parent-source-spans.rs

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// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// no-prefer-dynamic
rustc: Stabilize much of the `proc_macro` feature This commit stabilizes some of the `proc_macro` language feature as well as a number of APIs in the `proc_macro` crate as [previously discussed][1]. This means that on stable Rust you can now define custom procedural macros which operate as attributes attached to items or `macro_rules!`-like bang-style invocations. This extends the suite of currently stable procedural macros, custom derives, with custom attributes and custom bang macros. Note though that despite the stabilization in this commit procedural macros are still not usable on stable Rust. To stabilize that we'll need to stabilize at least part of the `use_extern_macros` feature. Currently you can define a procedural macro attribute but you can't import it to call it! A summary of the changes made in this PR (as well as the various consequences) is: * The `proc_macro` language and library features are now stable. * Other APIs not stabilized in the `proc_macro` crate are now named under a different feature, such as `proc_macro_diagnostic` or `proc_macro_span`. * A few checks in resolution for `proc_macro` being enabled have switched over to `use_extern_macros` being enabled. This means that code using `#![feature(proc_macro)]` today will likely need to move to `#![feature(use_extern_macros)]`. It's intended that this PR, once landed, will be followed up with an attempt to stabilize a small slice of `use_extern_macros` just for procedural macros to make this feature 100% usable on stable. [1]: https://internals.rust-lang.org/t/help-stabilize-a-subset-of-macros-2-0/7252
2018-07-03 17:36:31 -05:00
#![feature(proc_macro_diagnostic, proc_macro_span)]
#![crate_type = "proc-macro"]
extern crate proc_macro;
proc_macro: Reorganize public API This commit is a reorganization of the `proc_macro` crate's public user-facing API. This is the result of a number of discussions at the recent Rust All-Hands where we're hoping to get the `proc_macro` crate into ship shape for stabilization of a subset of its functionality in the Rust 2018 release. The reorganization here is motivated by experiences from the `proc-macro2`, `quote`, and `syn` crates on crates.io (and other crates which depend on them). The main focus is future flexibility along with making a few more operations consistent and/or fixing bugs. A summary of the changes made from today's `proc_macro` API is: * The `TokenNode` enum has been removed and the public fields of `TokenTree` have also been removed. Instead the `TokenTree` type is now a public enum (what `TokenNode` was) and each variant is an opaque struct which internally contains `Span` information. This makes the various tokens a bit more consistent, require fewer wrappers, and otherwise provides good future-compatibility as opaque structs are easy to modify later on. * `Literal` integer constructors have been expanded to be unambiguous as to what they're doing and also allow for more future flexibility. Previously constructors like `Literal::float` and `Literal::integer` were used to create unsuffixed literals and the concrete methods like `Literal::i32` would create a suffixed token. This wasn't immediately clear to all users (the suffixed/unsuffixed aspect) and having *one* constructor for unsuffixed literals required us to pick a largest type which may not always be true. To fix these issues all constructors are now of the form `Literal::i32_unsuffixed` or `Literal::i32_suffixed` (for all integral types). This should allow future compatibility as well as being immediately clear what's suffixed and what isn't. * Each variant of `TokenTree` internally contains a `Span` which can also be configured via `set_span`. For example `Literal` and `Term` now both internally contain a `Span` rather than having it stored in an auxiliary location. * Constructors of all tokens are called `new` now (aka `Term::intern` is gone) and most do not take spans. Manufactured tokens typically don't have a fresh span to go with them and the span is purely used for error-reporting **except** the span for `Term`, which currently affects hygiene. The default spans for all these constructed tokens is `Span::call_site()` for now. The `Term` type's constructor explicitly requires passing in a `Span` to provide future-proofing against possible hygiene changes. It's intended that a first pass of stabilization will likely only stabilize `Span::call_site()` which is an explicit opt-in for "I would like no hygiene here please". The intention here is to make this explicit in procedural macros to be forwards-compatible with a hygiene-specifying solution. * Some of the conversions for `TokenStream` have been simplified a little. * The `TokenTreeIter` iterator was renamed to `token_stream::IntoIter`. Overall the hope is that this is the "final pass" at the API of `TokenStream` and most of `TokenTree` before stabilization. Explicitly left out here is any changes to `Span`'s API which will likely need to be re-evaluated before stabilization. All changes in this PR have already been reflected to the [`proc-macro2`], `quote`, and `syn` crates. New versions of all these crates have also been published to crates.io. Once this lands in nightly I plan on making an internals post again summarizing the changes made here and also calling on all macro authors to give the APIs a spin and see how they work. Hopefully pending no major issues we can then have an FCP to stabilize later this cycle! [`proc-macro2`]: https://docs.rs/proc-macro2/0.3.1/proc_macro2/
2018-04-02 10:19:32 -05:00
use proc_macro::{TokenStream, TokenTree, Span};
fn lit_span(tt: TokenTree) -> (Span, String) {
proc_macro: Reorganize public API This commit is a reorganization of the `proc_macro` crate's public user-facing API. This is the result of a number of discussions at the recent Rust All-Hands where we're hoping to get the `proc_macro` crate into ship shape for stabilization of a subset of its functionality in the Rust 2018 release. The reorganization here is motivated by experiences from the `proc-macro2`, `quote`, and `syn` crates on crates.io (and other crates which depend on them). The main focus is future flexibility along with making a few more operations consistent and/or fixing bugs. A summary of the changes made from today's `proc_macro` API is: * The `TokenNode` enum has been removed and the public fields of `TokenTree` have also been removed. Instead the `TokenTree` type is now a public enum (what `TokenNode` was) and each variant is an opaque struct which internally contains `Span` information. This makes the various tokens a bit more consistent, require fewer wrappers, and otherwise provides good future-compatibility as opaque structs are easy to modify later on. * `Literal` integer constructors have been expanded to be unambiguous as to what they're doing and also allow for more future flexibility. Previously constructors like `Literal::float` and `Literal::integer` were used to create unsuffixed literals and the concrete methods like `Literal::i32` would create a suffixed token. This wasn't immediately clear to all users (the suffixed/unsuffixed aspect) and having *one* constructor for unsuffixed literals required us to pick a largest type which may not always be true. To fix these issues all constructors are now of the form `Literal::i32_unsuffixed` or `Literal::i32_suffixed` (for all integral types). This should allow future compatibility as well as being immediately clear what's suffixed and what isn't. * Each variant of `TokenTree` internally contains a `Span` which can also be configured via `set_span`. For example `Literal` and `Term` now both internally contain a `Span` rather than having it stored in an auxiliary location. * Constructors of all tokens are called `new` now (aka `Term::intern` is gone) and most do not take spans. Manufactured tokens typically don't have a fresh span to go with them and the span is purely used for error-reporting **except** the span for `Term`, which currently affects hygiene. The default spans for all these constructed tokens is `Span::call_site()` for now. The `Term` type's constructor explicitly requires passing in a `Span` to provide future-proofing against possible hygiene changes. It's intended that a first pass of stabilization will likely only stabilize `Span::call_site()` which is an explicit opt-in for "I would like no hygiene here please". The intention here is to make this explicit in procedural macros to be forwards-compatible with a hygiene-specifying solution. * Some of the conversions for `TokenStream` have been simplified a little. * The `TokenTreeIter` iterator was renamed to `token_stream::IntoIter`. Overall the hope is that this is the "final pass" at the API of `TokenStream` and most of `TokenTree` before stabilization. Explicitly left out here is any changes to `Span`'s API which will likely need to be re-evaluated before stabilization. All changes in this PR have already been reflected to the [`proc-macro2`], `quote`, and `syn` crates. New versions of all these crates have also been published to crates.io. Once this lands in nightly I plan on making an internals post again summarizing the changes made here and also calling on all macro authors to give the APIs a spin and see how they work. Hopefully pending no major issues we can then have an FCP to stabilize later this cycle! [`proc-macro2`]: https://docs.rs/proc-macro2/0.3.1/proc_macro2/
2018-04-02 10:19:32 -05:00
match tt {
TokenTree::Literal(..) |
TokenTree::Group(..) => (tt.span(), tt.to_string().trim().into()),
_ => panic!("expected a literal in token tree, got: {:?}", tt)
}
}
#[proc_macro]
pub fn parent_source_spans(input: TokenStream) -> TokenStream {
let mut tokens = input.into_iter();
let (sp1, str1) = lit_span(tokens.next().expect("first string"));
let _ = tokens.next();
let (sp2, str2) = lit_span(tokens.next().expect("second string"));
sp1.error(format!("first final: {}", str1)).emit();
sp2.error(format!("second final: {}", str2)).emit();
if let (Some(p1), Some(p2)) = (sp1.parent(), sp2.parent()) {
p1.error(format!("first parent: {}", str1)).emit();
p2.error(format!("second parent: {}", str2)).emit();
if let (Some(gp1), Some(gp2)) = (p1.parent(), p2.parent()) {
gp1.error(format!("first grandparent: {}", str1)).emit();
gp2.error(format!("second grandparent: {}", str2)).emit();
}
}
sp1.source().error(format!("first source: {}", str1)).emit();
sp2.source().error(format!("second source: {}", str2)).emit();
"ok".parse().unwrap()
}