mirror of
https://github.com/rtic-rs/rtic.git
synced 2024-12-11 12:47:16 +01:00
63 lines
No EOL
11 KiB
HTML
63 lines
No EOL
11 KiB
HTML
<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="github crates-io docs-rs"><title>proc_macro2 - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-b0742ba02757f159.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="proc_macro2" data-themes="" data-resource-suffix="" data-rustdoc-version="1.83.0 (90b35a623 2024-11-26)" data-channel="1.83.0" data-search-js="search-f0d225181b97f9a4.js" data-settings-js="settings-805db61a62df4bd2.js" ><script src="../static.files/storage-1d39b6787ed640ff.js"></script><script defer src="../crates.js"></script><script defer src="../static.files/main-f070b9041d14864c.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-0111fcff984fae8f.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc mod crate"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../proc_macro2/index.html">proc_<wbr>macro2</a><span class="version">1.0.92</span></h2></div><div class="sidebar-elems"><ul class="block"><li><a id="all-types" href="all.html">All Items</a></li></ul><section id="rustdoc-toc"><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#usage" title="Usage">Usage</a></li><li><a href="#unstable-features" title="Unstable features">Unstable features</a></li><li><a href="#thread-safety" title="Thread-Safety">Thread-Safety</a></li></ul><h3><a href="#modules">Crate Items</a></h3><ul class="block"><li><a href="#modules" title="Modules">Modules</a></li><li><a href="#structs" title="Structs">Structs</a></li><li><a href="#enums" title="Enums">Enums</a></li></ul></section><div id="rustdoc-modnav"></div></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1>Crate <span>proc_macro2</span><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../src/proc_macro2/lib.rs.html#1-1389">source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p><a href="https://github.com/dtolnay/proc-macro2"><img src="https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github" alt="github" /></a> <a href="https://crates.io/crates/proc-macro2"><img src="https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust" alt="crates-io" /></a> <a href="index.html" title="mod proc_macro2"><img src="https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs" alt="docs-rs" /></a></p>
|
||
<br>
|
||
<p>A wrapper around the procedural macro API of the compiler’s <a href="https://doc.rust-lang.org/proc_macro/"><code>proc_macro</code></a>
|
||
crate. This library serves two purposes:</p>
|
||
<ul>
|
||
<li>
|
||
<p><strong>Bring proc-macro-like functionality to other contexts like build.rs and
|
||
main.rs.</strong> Types from <code>proc_macro</code> are entirely specific to procedural
|
||
macros and cannot ever exist in code outside of a procedural macro.
|
||
Meanwhile <code>proc_macro2</code> types may exist anywhere including non-macro code.
|
||
By developing foundational libraries like <a href="https://github.com/dtolnay/syn">syn</a> and <a href="https://github.com/dtolnay/quote">quote</a> against
|
||
<code>proc_macro2</code> rather than <code>proc_macro</code>, the procedural macro ecosystem
|
||
becomes easily applicable to many other use cases and we avoid
|
||
reimplementing non-macro equivalents of those libraries.</p>
|
||
</li>
|
||
<li>
|
||
<p><strong>Make procedural macros unit testable.</strong> As a consequence of being
|
||
specific to procedural macros, nothing that uses <code>proc_macro</code> can be
|
||
executed from a unit test. In order for helper libraries or components of
|
||
a macro to be testable in isolation, they must be implemented using
|
||
<code>proc_macro2</code>.</p>
|
||
</li>
|
||
</ul>
|
||
<h2 id="usage"><a class="doc-anchor" href="#usage">§</a>Usage</h2>
|
||
<p>The skeleton of a typical procedural macro typically looks like this:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">extern crate </span>proc_macro;
|
||
|
||
<span class="attr">#[proc_macro_derive(MyDerive)]
|
||
</span><span class="kw">pub fn </span>my_derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
|
||
<span class="kw">let </span>input = proc_macro2::TokenStream::from(input);
|
||
|
||
<span class="kw">let </span>output: proc_macro2::TokenStream = {
|
||
<span class="comment">/* transform input */
|
||
</span>};
|
||
|
||
proc_macro::TokenStream::from(output)
|
||
}</code></pre></div>
|
||
<p>If parsing with <a href="https://github.com/dtolnay/syn">Syn</a>, you’ll use <a href="https://docs.rs/syn/2.0/syn/macro.parse_macro_input.html"><code>parse_macro_input!</code></a> instead to
|
||
propagate parse errors correctly back to the compiler when parsing fails.</p>
|
||
<h2 id="unstable-features"><a class="doc-anchor" href="#unstable-features">§</a>Unstable features</h2>
|
||
<p>The default feature set of proc-macro2 tracks the most recent stable
|
||
compiler API. Functionality in <code>proc_macro</code> that is not yet stable is not
|
||
exposed by proc-macro2 by default.</p>
|
||
<p>To opt into the additional APIs available in the most recent nightly
|
||
compiler, the <code>procmacro2_semver_exempt</code> config flag must be passed to
|
||
rustc. We will polyfill those nightly-only APIs back to Rust 1.56.0. As
|
||
these are unstable APIs that track the nightly compiler, minor versions of
|
||
proc-macro2 may make breaking changes to them at any time.</p>
|
||
<div class="example-wrap"><pre class="language-sh"><code>RUSTFLAGS='--cfg procmacro2_semver_exempt' cargo build</code></pre></div>
|
||
<p>Note that this must not only be done for your crate, but for any crate that
|
||
depends on your crate. This infectious nature is intentional, as it serves
|
||
as a reminder that you are outside of the normal semver guarantees.</p>
|
||
<p>Semver exempt methods are marked as such in the proc-macro2 documentation.</p>
|
||
<h2 id="thread-safety"><a class="doc-anchor" href="#thread-safety">§</a>Thread-Safety</h2>
|
||
<p>Most types in this crate are <code>!Sync</code> because the underlying compiler
|
||
types make use of thread-local memory, meaning they cannot be accessed from
|
||
a different thread.</p>
|
||
</div></details><h2 id="modules" class="section-header">Modules<a href="#modules" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="mod" href="extra/index.html" title="mod proc_macro2::extra">extra</a></div><div class="desc docblock-short">Items which do not have a correspondence to any API in the proc_macro crate,
|
||
but are necessary to include in proc-macro2.</div></li><li><div class="item-name"><a class="mod" href="token_stream/index.html" title="mod proc_macro2::token_stream">token_<wbr>stream</a></div><div class="desc docblock-short">Public implementation details for the <code>TokenStream</code> type, such as iterators.</div></li></ul><h2 id="structs" class="section-header">Structs<a href="#structs" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="struct" href="struct.Group.html" title="struct proc_macro2::Group">Group</a></div><div class="desc docblock-short">A delimited token stream.</div></li><li><div class="item-name"><a class="struct" href="struct.Ident.html" title="struct proc_macro2::Ident">Ident</a></div><div class="desc docblock-short">A word of Rust code, which may be a keyword or legal variable name.</div></li><li><div class="item-name"><a class="struct" href="struct.LexError.html" title="struct proc_macro2::LexError">LexError</a></div><div class="desc docblock-short">Error returned from <code>TokenStream::from_str</code>.</div></li><li><div class="item-name"><a class="struct" href="struct.Literal.html" title="struct proc_macro2::Literal">Literal</a></div><div class="desc docblock-short">A literal string (<code>"hello"</code>), byte string (<code>b"hello"</code>), character (<code>'a'</code>),
|
||
byte character (<code>b'a'</code>), an integer or floating point number with or without
|
||
a suffix (<code>1</code>, <code>1u8</code>, <code>2.3</code>, <code>2.3f32</code>).</div></li><li><div class="item-name"><a class="struct" href="struct.Punct.html" title="struct proc_macro2::Punct">Punct</a></div><div class="desc docblock-short">A <code>Punct</code> is a single punctuation character like <code>+</code>, <code>-</code> or <code>#</code>.</div></li><li><div class="item-name"><a class="struct" href="struct.Span.html" title="struct proc_macro2::Span">Span</a></div><div class="desc docblock-short">A region of source code, along with macro expansion information.</div></li><li><div class="item-name"><a class="struct" href="struct.TokenStream.html" title="struct proc_macro2::TokenStream">Token<wbr>Stream</a></div><div class="desc docblock-short">An abstract stream of tokens, or more concretely a sequence of token trees.</div></li></ul><h2 id="enums" class="section-header">Enums<a href="#enums" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="enum" href="enum.Delimiter.html" title="enum proc_macro2::Delimiter">Delimiter</a></div><div class="desc docblock-short">Describes how a sequence of token trees is delimited.</div></li><li><div class="item-name"><a class="enum" href="enum.Spacing.html" title="enum proc_macro2::Spacing">Spacing</a></div><div class="desc docblock-short">Whether a <code>Punct</code> is followed immediately by another <code>Punct</code> or followed by
|
||
another token or whitespace.</div></li><li><div class="item-name"><a class="enum" href="enum.TokenTree.html" title="enum proc_macro2::TokenTree">Token<wbr>Tree</a></div><div class="desc docblock-short">A single token or a delimited sequence of token trees (e.g. <code>[1, (), ..]</code>).</div></li></ul></section></div></main></body></html> |