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Update macro-expansion.md 

removing parens
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Tbkhi 2024-03-11 07:33:36 -03:00 committed by nora
parent 5676ddd217
commit 07aa8b109f
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src/macro-expansion.md
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@ -36,14 +36,14 @@ handled in [`rustc_expand::config`][cfg].
Firstly, expansion happens at the crate level. Given a raw source code for Firstly, expansion happens at the crate level. Given a raw source code for
a crate, the compiler will produce a massive `AST` with all `macro`s expanded, all a crate, the compiler will produce a massive `AST` with all `macro`s expanded, all
modules inlined, etc. The primary entry point for this process is the modules inlined, etc. The primary entry point for this process is the
[`MacroExpander::fully_expand_fragment()`][fef] method. With few exceptions, we [`MacroExpander::fully_expand_fragment`][fef] method. With few exceptions, we
use this method on the whole crate (see ["Eager Expansion"](#eager-expansion) use this method on the whole crate (see ["Eager Expansion"](#eager-expansion)
below for more detailed discussion of edge case expansion issues). below for more detailed discussion of edge case expansion issues).
[`rustc_builtin_macros`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_builtin_macros/index.html [`rustc_builtin_macros`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_builtin_macros/index.html
[reb]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_expand/build/index.html [reb]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_expand/build/index.html
At a high level, [`fully_expand_fragment()`][fef] works in iterations. We keep a At a high level, [`fully_expand_fragment`][fef] works in iterations. We keep a
queue of unresolved `macro` invocations (i.e. `macro`s we haven't found the queue of unresolved `macro` invocations (i.e. `macro`s we haven't found the
definition of yet). We repeatedly try to pick a `macro` from the queue, resolve definition of yet). We repeatedly try to pick a `macro` from the queue, resolve
it, expand it, and integrate it back. If we can't make progress in an it, expand it, and integrate it back. If we can't make progress in an
@ -67,7 +67,7 @@ iteration, this represents a compile error. Here is the [algorithm][original]:
each of which are a token (punctuation, identifier, or literal) or a each of which are a token (punctuation, identifier, or literal) or a
delimited group (anything inside `()`/`[]`/`{}`)). delimited group (anything inside `()`/`[]`/`{}`)).
- At this point, we know everything about the `macro` itself and can - At this point, we know everything about the `macro` itself and can
call [`set_expn_data()`] to fill in its properties in the global call [`set_expn_data`] to fill in its properties in the global
data; that is the [hygiene] data associated with [`ExpnId`] (see data; that is the [hygiene] data associated with [`ExpnId`] (see
[Hygiene][hybelow] below). [Hygiene][hybelow] below).
2. Integrate that piece of `AST` into the currently-existing though 2. Integrate that piece of `AST` into the currently-existing though
@ -88,7 +88,7 @@ iteration, this represents a compile error. Here is the [algorithm][original]:
- Names are put into modules (from the resolver's point of - Names are put into modules (from the resolver's point of
view) by [`BuildReducedGraphVisitor`]. view) by [`BuildReducedGraphVisitor`].
3. After expanding a single `macro` and integrating its output, continue 3. After expanding a single `macro` and integrating its output, continue
to the next iteration of [`fully_expand_fragment()`][fef]. to the next iteration of [`fully_expand_fragment`][fef].
5. If it's not resolved: 5. If it's not resolved:
1. Put the `macro` back in the queue. 1. Put the `macro` back in the queue.
2. Continue to next iteration... 2. Continue to next iteration...
@ -100,7 +100,7 @@ iteration, this represents a compile error. Here is the [algorithm][original]:
[`ExpnId`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/hygiene/struct.ExpnId.html [`ExpnId`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/hygiene/struct.ExpnId.html
[`InvocationCollector`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_expand/expand/struct.InvocationCollector.html [`InvocationCollector`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_expand/expand/struct.InvocationCollector.html
[`NodeId`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/node_id/struct.NodeId.html [`NodeId`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/node_id/struct.NodeId.html
[`set_expn_data()`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/hygiene/struct.LocalExpnId.html#method.set_expn_data [`set_expn_data`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/hygiene/struct.LocalExpnId.html#method.set_expn_data
[`SyntaxContext`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/hygiene/struct.SyntaxContext.html [`SyntaxContext`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/hygiene/struct.SyntaxContext.html
[`TokenStream`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/tokenstream/struct.TokenStream.html [`TokenStream`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/tokenstream/struct.TokenStream.html
[defpath]: hir.md#identifiers-in-the-hir [defpath]: hir.md#identifiers-in-the-hir
@ -262,7 +262,7 @@ crate.
All of these hierarchies need some sort of "`macro` ID" to identify individual All of these hierarchies need some sort of "`macro` ID" to identify individual
elements in the chain of expansions. This ID is [`ExpnId`]. All `macro`s receive elements in the chain of expansions. This ID is [`ExpnId`]. All `macro`s receive
an integer ID, assigned continuously starting from 0 as we discover new `macro` an integer ID, assigned continuously starting from 0 as we discover new `macro`
calls. All hierarchies start at [`ExpnId::root()`][rootid], which is its own calls. All hierarchies start at [`ExpnId::root`][rootid], which is its own
parent. parent.
The [`rustc_span::hygiene`][hy] library contains all of the hygiene-related algorithms The [`rustc_span::hygiene`][hy] library contains all of the hygiene-related algorithms
@ -346,7 +346,7 @@ macro m() { ident }
m!(); m!();
``` ```
Here `ident` originally has context [`SyntaxContext::root()`][scr]. `ident` has Here `ident` originally has context [`SyntaxContext::root`][scr]. `ident` has
context `ROOT -> id(m)` after it's produced by `m`. context `ROOT -> id(m)` after it's produced by `m`.
[scr]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/hygiene/struct.SyntaxContext.html#method.root [scr]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/hygiene/struct.SyntaxContext.html#method.root