1//! Internal interface for communicating between a `proc_macro` client
2//! (a proc macro crate) and a `proc_macro` server (a compiler front-end).
3//!
4//! Serialization (with C ABI buffers) and unique integer handles are employed
5//! to allow safely interfacing between two copies of `proc_macro` built
6//! (from the same source) by different compilers with potentially mismatching
7//! Rust ABIs (e.g., stage0/bin/rustc vs stage1/bin/rustc during bootstrap).
8
9#![deny(unsafe_code)]
10
11use crate::{Delimiter, Level, Spacing};
12use std::fmt;
13use std::hash::Hash;
14use std::marker;
15use std::mem;
16use std::ops::Bound;
17use std::ops::Range;
18use std::panic;
19use std::sync::Once;
20use std::thread;
21
22/// Higher-order macro describing the server RPC API, allowing automatic
23/// generation of type-safe Rust APIs, both client-side and server-side.
24///
25/// `with_api!(MySelf, my_self, my_macro)` expands to:
26/// ```rust,ignore (pseudo-code)
27/// my_macro! {
28/// // ...
29/// Literal {
30/// // ...
31/// fn character(ch: char) -> MySelf::Literal;
32/// // ...
33/// fn span(my_self: &MySelf::Literal) -> MySelf::Span;
34/// fn set_span(my_self: &mut MySelf::Literal, span: MySelf::Span);
35/// },
36/// // ...
37/// }
38/// ```
39///
40/// The first two arguments serve to customize the arguments names
41/// and argument/return types, to enable several different usecases:
42///
43/// If `my_self` is just `self`, then each `fn` signature can be used
44/// as-is for a method. If it's anything else (`self_` in practice),
45/// then the signatures don't have a special `self` argument, and
46/// can, therefore, have a different one introduced.
47///
48/// If `MySelf` is just `Self`, then the types are only valid inside
49/// a trait or a trait impl, where the trait has associated types
50/// for each of the API types. If non-associated types are desired,
51/// a module name (`self` in practice) can be used instead of `Self`.
52macro_rules! with_api {
53 ($S:ident, $self:ident, $m:ident) => {
54 $m! {
55 FreeFunctions {
56 fn drop($self: $S::FreeFunctions);
57 fn injected_env_var(var: &str) -> Option<String>;
58 fn track_env_var(var: &str, value: Option<&str>);
59 fn track_path(path: &str);
60 fn literal_from_str(s: &str) -> Result<Literal<$S::Span, $S::Symbol>, ()>;
61 fn emit_diagnostic(diagnostic: Diagnostic<$S::Span>);
62 },
63 TokenStream {
64 fn drop($self: $S::TokenStream);
65 fn clone($self: &$S::TokenStream) -> $S::TokenStream;
66 fn is_empty($self: &$S::TokenStream) -> bool;
67 fn expand_expr($self: &$S::TokenStream) -> Result<$S::TokenStream, ()>;
68 fn from_str(src: &str) -> $S::TokenStream;
69 fn to_string($self: &$S::TokenStream) -> String;
70 fn from_token_tree(
71 tree: TokenTree<$S::TokenStream, $S::Span, $S::Symbol>,
72 ) -> $S::TokenStream;
73 fn concat_trees(
74 base: Option<$S::TokenStream>,
75 trees: Vec<TokenTree<$S::TokenStream, $S::Span, $S::Symbol>>,
76 ) -> $S::TokenStream;
77 fn concat_streams(
78 base: Option<$S::TokenStream>,
79 streams: Vec<$S::TokenStream>,
80 ) -> $S::TokenStream;
81 fn into_trees(
82 $self: $S::TokenStream
83 ) -> Vec<TokenTree<$S::TokenStream, $S::Span, $S::Symbol>>;
84 },
85 SourceFile {
86 fn drop($self: $S::SourceFile);
87 fn clone($self: &$S::SourceFile) -> $S::SourceFile;
88 fn eq($self: &$S::SourceFile, other: &$S::SourceFile) -> bool;
89 fn path($self: &$S::SourceFile) -> String;
90 fn is_real($self: &$S::SourceFile) -> bool;
91 },
92 Span {
93 fn debug($self: $S::Span) -> String;
94 fn source_file($self: $S::Span) -> $S::SourceFile;
95 fn parent($self: $S::Span) -> Option<$S::Span>;
96 fn source($self: $S::Span) -> $S::Span;
97 fn byte_range($self: $S::Span) -> Range<usize>;
98 fn start($self: $S::Span) -> $S::Span;
99 fn end($self: $S::Span) -> $S::Span;
100 fn line($self: $S::Span) -> usize;
101 fn column($self: $S::Span) -> usize;
102 fn join($self: $S::Span, other: $S::Span) -> Option<$S::Span>;
103 fn subspan($self: $S::Span, start: Bound<usize>, end: Bound<usize>) -> Option<$S::Span>;
104 fn resolved_at($self: $S::Span, at: $S::Span) -> $S::Span;
105 fn source_text($self: $S::Span) -> Option<String>;
106 fn save_span($self: $S::Span) -> usize;
107 fn recover_proc_macro_span(id: usize) -> $S::Span;
108 },
109 Symbol {
110 fn normalize_and_validate_ident(string: &str) -> Result<$S::Symbol, ()>;
111 },
112 }
113 };
114}
115
116// Similar to `with_api`, but only lists the types requiring handles, and they
117// are divided into the two storage categories.
118macro_rules! with_api_handle_types {
119 ($m:ident) => {
120 $m! {
121 'owned:
122 FreeFunctions,
123 TokenStream,
124 SourceFile,
125
126 'interned:
127 Span,
128 // Symbol is handled manually
129 }
130 };
131}
132
133// FIXME(eddyb) this calls `encode` for each argument, but in reverse,
134// to match the ordering in `reverse_decode`.
135macro_rules! reverse_encode {
136 ($writer:ident;) => {};
137 ($writer:ident; $first:ident $(, $rest:ident)*) => {
138 reverse_encode!($writer; $($rest),*);
139 $first.encode(&mut $writer, &mut ());
140 }
141}
142
143// FIXME(eddyb) this calls `decode` for each argument, but in reverse,
144// to avoid borrow conflicts from borrows started by `&mut` arguments.
145macro_rules! reverse_decode {
146 ($reader:ident, $s:ident;) => {};
147 ($reader:ident, $s:ident; $first:ident: $first_ty:ty $(, $rest:ident: $rest_ty:ty)*) => {
148 reverse_decode!($reader, $s; $($rest: $rest_ty),*);
149 let $first = <$first_ty>::decode(&mut $reader, $s);
150 }
151}
152
153#[allow(unsafe_code)]
154mod arena;
155#[allow(unsafe_code)]
156mod buffer;
157#[deny(unsafe_code)]
158pub mod client;
159#[allow(unsafe_code)]
160mod closure;
161#[forbid(unsafe_code)]
162mod fxhash;
163#[forbid(unsafe_code)]
164mod handle;
165#[macro_use]
166#[forbid(unsafe_code)]
167mod rpc;
168#[allow(unsafe_code)]
169mod selfless_reify;
170#[forbid(unsafe_code)]
171pub mod server;
172#[allow(unsafe_code)]
173mod symbol;
174
175use buffer::Buffer;
176pub use rpc::PanicMessage;
177use rpc::{Decode, DecodeMut, Encode, Reader, Writer};
178
179/// Configuration for establishing an active connection between a server and a
180/// client. The server creates the bridge config (`run_server` in `server.rs`),
181/// then passes it to the client through the function pointer in the `run` field
182/// of `client::Client`. The client constructs a local `Bridge` from the config
183/// in TLS during its execution (`Bridge::{enter, with}` in `client.rs`).
184#[repr(C)]
185pub struct BridgeConfig<'a> {
186 /// Buffer used to pass initial input to the client.
187 input: Buffer,
188
189 /// Server-side function that the client uses to make requests.
190 dispatch: closure::Closure<'a, Buffer, Buffer>,
191
192 /// If 'true', always invoke the default panic hook
193 force_show_panics: bool,
194
195 // Prevent Send and Sync impls. `!Send`/`!Sync` is the usual way of doing
196 // this, but that requires unstable features. rust-analyzer uses this code
197 // and avoids unstable features.
198 _marker: marker::PhantomData<*mut ()>,
199}
200
201#[forbid(unsafe_code)]
202#[allow(non_camel_case_types)]
203mod api_tags {
204 use super::rpc::{DecodeMut, Encode, Reader, Writer};
205
206 macro_rules! declare_tags {
207 ($($name:ident {
208 $(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)*;)*
209 }),* $(,)?) => {
210 $(
211 pub(super) enum $name {
212 $($method),*
213 }
214 rpc_encode_decode!(enum $name { $($method),* });
215 )*
216
217 pub(super) enum Method {
218 $($name($name)),*
219 }
220 rpc_encode_decode!(enum Method { $($name(m)),* });
221 }
222 }
223 with_api!(self, self, declare_tags);
224}
225
226/// Helper to wrap associated types to allow trait impl dispatch.
227/// That is, normally a pair of impls for `T::Foo` and `T::Bar`
228/// can overlap, but if the impls are, instead, on types like
229/// `Marked<T::Foo, Foo>` and `Marked<T::Bar, Bar>`, they can't.
230trait Mark {
231 type Unmarked;
232 fn mark(unmarked: Self::Unmarked) -> Self;
233}
234
235/// Unwrap types wrapped by `Mark::mark` (see `Mark` for details).
236trait Unmark {
237 type Unmarked;
238 fn unmark(self) -> Self::Unmarked;
239}
240
241#[derive(Copy, Clone, PartialEq, Eq, Hash)]
242struct Marked<T, M> {
243 value: T,
244 _marker: marker::PhantomData<M>,
245}
246
247impl<T, M> Mark for Marked<T, M> {
248 type Unmarked = T;
249 fn mark(unmarked: Self::Unmarked) -> Self {
250 Marked { value: unmarked, _marker: marker::PhantomData }
251 }
252}
253impl<T, M> Unmark for Marked<T, M> {
254 type Unmarked = T;
255 fn unmark(self) -> Self::Unmarked {
256 self.value
257 }
258}
259impl<'a, T, M> Unmark for &'a Marked<T, M> {
260 type Unmarked = &'a T;
261 fn unmark(self) -> Self::Unmarked {
262 &self.value
263 }
264}
265impl<'a, T, M> Unmark for &'a mut Marked<T, M> {
266 type Unmarked = &'a mut T;
267 fn unmark(self) -> Self::Unmarked {
268 &mut self.value
269 }
270}
271
272impl<T: Mark> Mark for Vec<T> {
273 type Unmarked = Vec<T::Unmarked>;
274 fn mark(unmarked: Self::Unmarked) -> Self {
275 // Should be a no-op due to std's in-place collect optimizations.
276 unmarked.into_iter().map(T::mark).collect()
277 }
278}
279impl<T: Unmark> Unmark for Vec<T> {
280 type Unmarked = Vec<T::Unmarked>;
281 fn unmark(self) -> Self::Unmarked {
282 // Should be a no-op due to std's in-place collect optimizations.
283 self.into_iter().map(T::unmark).collect()
284 }
285}
286
287macro_rules! mark_noop {
288 ($($ty:ty),* $(,)?) => {
289 $(
290 impl Mark for $ty {
291 type Unmarked = Self;
292 fn mark(unmarked: Self::Unmarked) -> Self {
293 unmarked
294 }
295 }
296 impl Unmark for $ty {
297 type Unmarked = Self;
298 fn unmark(self) -> Self::Unmarked {
299 self
300 }
301 }
302 )*
303 }
304}
305mark_noop! {
306 (),
307 bool,
308 char,
309 &'_ [u8],
310 &'_ str,
311 String,
312 u8,
313 usize,
314 Delimiter,
315 LitKind,
316 Level,
317 Spacing,
318}
319
320rpc_encode_decode!(
321 enum Delimiter {
322 Parenthesis,
323 Brace,
324 Bracket,
325 None,
326 }
327);
328rpc_encode_decode!(
329 enum Level {
330 Error,
331 Warning,
332 Note,
333 Help,
334 }
335);
336rpc_encode_decode!(
337 enum Spacing {
338 Alone,
339 Joint,
340 }
341);
342
343#[derive(Copy, Clone, Eq, PartialEq, Debug)]
344pub enum LitKind {
345 Byte,
346 Char,
347 Integer,
348 Float,
349 Str,
350 StrRaw(u8),
351 ByteStr,
352 ByteStrRaw(u8),
353 CStr,
354 CStrRaw(u8),
355 // This should have an `ErrorGuaranteed`, except that type isn't available
356 // in this crate. (Imagine it is there.) Hence the `WithGuar` suffix. Must
357 // only be constructed in `LitKind::from_internal`, where an
358 // `ErrorGuaranteed` is available.
359 ErrWithGuar,
360}
361
362rpc_encode_decode!(
363 enum LitKind {
364 Byte,
365 Char,
366 Integer,
367 Float,
368 Str,
369 StrRaw(n),
370 ByteStr,
371 ByteStrRaw(n),
372 CStr,
373 CStrRaw(n),
374 ErrWithGuar,
375 }
376);
377
378macro_rules! mark_compound {
379 (struct $name:ident <$($T:ident),+> { $($field:ident),* $(,)? }) => {
380 impl<$($T: Mark),+> Mark for $name <$($T),+> {
381 type Unmarked = $name <$($T::Unmarked),+>;
382 fn mark(unmarked: Self::Unmarked) -> Self {
383 $name {
384 $($field: Mark::mark(unmarked.$field)),*
385 }
386 }
387 }
388
389 impl<$($T: Unmark),+> Unmark for $name <$($T),+> {
390 type Unmarked = $name <$($T::Unmarked),+>;
391 fn unmark(self) -> Self::Unmarked {
392 $name {
393 $($field: Unmark::unmark(self.$field)),*
394 }
395 }
396 }
397 };
398 (enum $name:ident <$($T:ident),+> { $($variant:ident $(($field:ident))?),* $(,)? }) => {
399 impl<$($T: Mark),+> Mark for $name <$($T),+> {
400 type Unmarked = $name <$($T::Unmarked),+>;
401 fn mark(unmarked: Self::Unmarked) -> Self {
402 match unmarked {
403 $($name::$variant $(($field))? => {
404 $name::$variant $((Mark::mark($field)))?
405 })*
406 }
407 }
408 }
409
410 impl<$($T: Unmark),+> Unmark for $name <$($T),+> {
411 type Unmarked = $name <$($T::Unmarked),+>;
412 fn unmark(self) -> Self::Unmarked {
413 match self {
414 $($name::$variant $(($field))? => {
415 $name::$variant $((Unmark::unmark($field)))?
416 })*
417 }
418 }
419 }
420 }
421}
422
423macro_rules! compound_traits {
424 ($($t:tt)*) => {
425 rpc_encode_decode!($($t)*);
426 mark_compound!($($t)*);
427 };
428}
429
430compound_traits!(
431 enum Bound<T> {
432 Included(x),
433 Excluded(x),
434 Unbounded,
435 }
436);
437
438compound_traits!(
439 enum Option<T> {
440 Some(t),
441 None,
442 }
443);
444
445compound_traits!(
446 enum Result<T, E> {
447 Ok(t),
448 Err(e),
449 }
450);
451
452#[derive(Copy, Clone)]
453pub struct DelimSpan<Span> {
454 pub open: Span,
455 pub close: Span,
456 pub entire: Span,
457}
458
459impl<Span: Copy> DelimSpan<Span> {
460 pub fn from_single(span: Span) -> Self {
461 DelimSpan { open: span, close: span, entire: span }
462 }
463}
464
465compound_traits!(struct DelimSpan<Span> { open, close, entire });
466
467#[derive(Clone)]
468pub struct Group<TokenStream, Span> {
469 pub delimiter: Delimiter,
470 pub stream: Option<TokenStream>,
471 pub span: DelimSpan<Span>,
472}
473
474compound_traits!(struct Group<TokenStream, Span> { delimiter, stream, span });
475
476#[derive(Clone)]
477pub struct Punct<Span> {
478 pub ch: u8,
479 pub joint: bool,
480 pub span: Span,
481}
482
483compound_traits!(struct Punct<Span> { ch, joint, span });
484
485#[derive(Copy, Clone, Eq, PartialEq)]
486pub struct Ident<Span, Symbol> {
487 pub sym: Symbol,
488 pub is_raw: bool,
489 pub span: Span,
490}
491
492compound_traits!(struct Ident<Span, Symbol> { sym, is_raw, span });
493
494#[derive(Clone, Eq, PartialEq)]
495pub struct Literal<Span, Symbol> {
496 pub kind: LitKind,
497 pub symbol: Symbol,
498 pub suffix: Option<Symbol>,
499 pub span: Span,
500}
501
502compound_traits!(struct Literal<Sp, Sy> { kind, symbol, suffix, span });
503
504#[derive(Clone)]
505pub enum TokenTree<TokenStream, Span, Symbol> {
506 Group(Group<TokenStream, Span>),
507 Punct(Punct<Span>),
508 Ident(Ident<Span, Symbol>),
509 Literal(Literal<Span, Symbol>),
510}
511
512compound_traits!(
513 enum TokenTree<TokenStream, Span, Symbol> {
514 Group(tt),
515 Punct(tt),
516 Ident(tt),
517 Literal(tt),
518 }
519);
520
521#[derive(Clone, Debug)]
522pub struct Diagnostic<Span> {
523 pub level: Level,
524 pub message: String,
525 pub spans: Vec<Span>,
526 pub children: Vec<Diagnostic<Span>>,
527}
528
529compound_traits!(
530 struct Diagnostic<Span> { level, message, spans, children }
531);
532
533/// Globals provided alongside the initial inputs for a macro expansion.
534/// Provides values such as spans which are used frequently to avoid RPC.
535#[derive(Clone)]
536pub struct ExpnGlobals<Span> {
537 pub def_site: Span,
538 pub call_site: Span,
539 pub mixed_site: Span,
540}
541
542compound_traits!(
543 struct ExpnGlobals<Span> { def_site, call_site, mixed_site }
544);
545
546compound_traits!(
547 struct Range<T> { start, end }
548);
549