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| </pre><pre class="rust"><code><span class="kw">use </span>std::collections::HashSet; |
| <span class="kw">use </span>syn::{punctuated::Punctuated, Expr, Ident, LitInt, LitStr, Path, Token}; |
| |
| <span class="kw">use </span>proc_macro2::TokenStream; |
| <span class="kw">use </span>quote::{quote, quote_spanned, ToTokens}; |
| <span class="kw">use </span>syn::ext::IdentExt <span class="kw">as _</span>; |
| <span class="kw">use </span>syn::parse::{Parse, ParseStream}; |
| |
| <span class="doccomment">/// Arguments to `#[instrument(err(...))]` and `#[instrument(ret(...))]` which describe how the |
| /// return value event should be emitted. |
| </span><span class="attribute">#[derive(Clone, Default, Debug)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>EventArgs { |
| level: <span class="prelude-ty">Option</span><Level>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) mode: FormatMode, |
| } |
| |
| <span class="attribute">#[derive(Clone, Default, Debug)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>InstrumentArgs { |
| level: <span class="prelude-ty">Option</span><Level>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) name: <span class="prelude-ty">Option</span><LitStr>, |
| target: <span class="prelude-ty">Option</span><LitStr>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) parent: <span class="prelude-ty">Option</span><Expr>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) follows_from: <span class="prelude-ty">Option</span><Expr>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) skips: HashSet<Ident>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) skip_all: bool, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) fields: <span class="prelude-ty">Option</span><Fields>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) err_args: <span class="prelude-ty">Option</span><EventArgs>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) ret_args: <span class="prelude-ty">Option</span><EventArgs>, |
| <span class="doccomment">/// Errors describing any unrecognized parse inputs that we skipped. |
| </span>parse_warnings: Vec<syn::Error>, |
| } |
| |
| <span class="kw">impl </span>InstrumentArgs { |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>level(<span class="kw-2">&</span><span class="self">self</span>) -> Level { |
| <span class="self">self</span>.level.clone().unwrap_or(Level::Info) |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>target(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw">impl </span>ToTokens { |
| <span class="kw">if let </span><span class="prelude-val">Some</span>(<span class="kw-2">ref </span>target) = <span class="self">self</span>.target { |
| <span class="macro">quote!</span>(#target) |
| } <span class="kw">else </span>{ |
| <span class="macro">quote!</span>(<span class="macro">module_path!</span>()) |
| } |
| } |
| |
| <span class="doccomment">/// Generate "deprecation" warnings for any unrecognized attribute inputs |
| /// that we skipped. |
| /// |
| /// For backwards compatibility, we need to emit compiler warnings rather |
| /// than errors for unrecognized inputs. Generating a fake deprecation is |
| /// the only way to do this on stable Rust right now. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>warnings(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw">impl </span>ToTokens { |
| <span class="kw">let </span>warnings = <span class="self">self</span>.parse_warnings.iter().map(|err| { |
| <span class="kw">let </span>msg = <span class="macro">format!</span>(<span class="string">"found unrecognized input, {}"</span>, err); |
| <span class="kw">let </span>msg = LitStr::new(<span class="kw-2">&</span>msg, err.span()); |
| <span class="comment">// TODO(eliza): This is a bit of a hack, but it's just about the |
| // only way to emit warnings from a proc macro on stable Rust. |
| // Eventually, when the `proc_macro::Diagnostic` API stabilizes, we |
| // should definitely use that instead. |
| </span><span class="macro">quote_spanned! </span>{err.span()=> |
| <span class="attribute">#[warn(deprecated)] |
| </span>{ |
| <span class="attribute">#[deprecated(since = <span class="string">"not actually deprecated"</span>, note = #msg)] |
| </span><span class="kw">const </span>TRACING_INSTRUMENT_WARNING: () = (); |
| <span class="kw">let _ </span>= TRACING_INSTRUMENT_WARNING; |
| } |
| } |
| }); |
| <span class="macro">quote! </span>{ |
| { #(#warnings)* } |
| } |
| } |
| } |
| |
| <span class="kw">impl </span>Parse <span class="kw">for </span>InstrumentArgs { |
| <span class="kw">fn </span>parse(input: ParseStream<<span class="lifetime">'_</span>>) -> syn::Result<<span class="self">Self</span>> { |
| <span class="kw">let </span><span class="kw-2">mut </span>args = <span class="self">Self</span>::default(); |
| <span class="kw">while </span>!input.is_empty() { |
| <span class="kw">let </span>lookahead = input.lookahead1(); |
| <span class="kw">if </span>lookahead.peek(kw::name) { |
| <span class="kw">if </span>args.name.is_some() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `name` argument"</span>)); |
| } |
| <span class="kw">let </span>name = input.parse::<StrArg<kw::name>>()<span class="question-mark">?</span>.value; |
| args.name = <span class="prelude-val">Some</span>(name); |
| } <span class="kw">else if </span>lookahead.peek(LitStr) { |
| <span class="comment">// XXX: apparently we support names as either named args with an |
| // sign, _or_ as unnamed string literals. That's weird, but |
| // changing it is apparently breaking. |
| </span><span class="kw">if </span>args.name.is_some() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `name` argument"</span>)); |
| } |
| args.name = <span class="prelude-val">Some</span>(input.parse()<span class="question-mark">?</span>); |
| } <span class="kw">else if </span>lookahead.peek(kw::target) { |
| <span class="kw">if </span>args.target.is_some() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `target` argument"</span>)); |
| } |
| <span class="kw">let </span>target = input.parse::<StrArg<kw::target>>()<span class="question-mark">?</span>.value; |
| args.target = <span class="prelude-val">Some</span>(target); |
| } <span class="kw">else if </span>lookahead.peek(kw::parent) { |
| <span class="kw">if </span>args.target.is_some() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `parent` argument"</span>)); |
| } |
| <span class="kw">let </span>parent = input.parse::<ExprArg<kw::parent>>()<span class="question-mark">?</span>; |
| args.parent = <span class="prelude-val">Some</span>(parent.value); |
| } <span class="kw">else if </span>lookahead.peek(kw::follows_from) { |
| <span class="kw">if </span>args.target.is_some() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `follows_from` argument"</span>)); |
| } |
| <span class="kw">let </span>follows_from = input.parse::<ExprArg<kw::follows_from>>()<span class="question-mark">?</span>; |
| args.follows_from = <span class="prelude-val">Some</span>(follows_from.value); |
| } <span class="kw">else if </span>lookahead.peek(kw::level) { |
| <span class="kw">if </span>args.level.is_some() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `level` argument"</span>)); |
| } |
| args.level = <span class="prelude-val">Some</span>(input.parse()<span class="question-mark">?</span>); |
| } <span class="kw">else if </span>lookahead.peek(kw::skip) { |
| <span class="kw">if </span>!args.skips.is_empty() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `skip` argument"</span>)); |
| } |
| <span class="kw">if </span>args.skip_all { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected either `skip` or `skip_all` argument"</span>)); |
| } |
| <span class="kw">let </span>Skips(skips) = input.parse()<span class="question-mark">?</span>; |
| args.skips = skips; |
| } <span class="kw">else if </span>lookahead.peek(kw::skip_all) { |
| <span class="kw">if </span>args.skip_all { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `skip_all` argument"</span>)); |
| } |
| <span class="kw">if </span>!args.skips.is_empty() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected either `skip` or `skip_all` argument"</span>)); |
| } |
| <span class="kw">let _ </span>= input.parse::<kw::skip_all>()<span class="question-mark">?</span>; |
| args.skip_all = <span class="bool-val">true</span>; |
| } <span class="kw">else if </span>lookahead.peek(kw::fields) { |
| <span class="kw">if </span>args.fields.is_some() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(input.error(<span class="string">"expected only a single `fields` argument"</span>)); |
| } |
| args.fields = <span class="prelude-val">Some</span>(input.parse()<span class="question-mark">?</span>); |
| } <span class="kw">else if </span>lookahead.peek(kw::err) { |
| <span class="kw">let _ </span>= input.parse::<kw::err>(); |
| <span class="kw">let </span>err_args = EventArgs::parse(input)<span class="question-mark">?</span>; |
| args.err_args = <span class="prelude-val">Some</span>(err_args); |
| } <span class="kw">else if </span>lookahead.peek(kw::ret) { |
| <span class="kw">let _ </span>= input.parse::<kw::ret>()<span class="question-mark">?</span>; |
| <span class="kw">let </span>ret_args = EventArgs::parse(input)<span class="question-mark">?</span>; |
| args.ret_args = <span class="prelude-val">Some</span>(ret_args); |
| } <span class="kw">else if </span>lookahead.peek(<span class="macro">Token!</span>[,]) { |
| <span class="kw">let _ </span>= input.parse::<<span class="macro">Token!</span>[,]>()<span class="question-mark">?</span>; |
| } <span class="kw">else </span>{ |
| <span class="comment">// We found a token that we didn't expect! |
| // We want to emit warnings for these, rather than errors, so |
| // we'll add it to the list of unrecognized inputs we've seen so |
| // far and keep going. |
| </span>args.parse_warnings.push(lookahead.error()); |
| <span class="comment">// Parse the unrecognized token tree to advance the parse |
| // stream, and throw it away so we can keep parsing. |
| </span><span class="kw">let _ </span>= input.parse::<proc_macro2::TokenTree>(); |
| } |
| } |
| <span class="prelude-val">Ok</span>(args) |
| } |
| } |
| |
| <span class="kw">impl </span>EventArgs { |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>level(<span class="kw-2">&</span><span class="self">self</span>, default: Level) -> Level { |
| <span class="self">self</span>.level.clone().unwrap_or(default) |
| } |
| } |
| |
| <span class="kw">impl </span>Parse <span class="kw">for </span>EventArgs { |
| <span class="kw">fn </span>parse(input: ParseStream<<span class="lifetime">'_</span>>) -> syn::Result<<span class="self">Self</span>> { |
| <span class="kw">if </span>!input.peek(syn::token::Paren) { |
| <span class="kw">return </span><span class="prelude-val">Ok</span>(<span class="self">Self</span>::default()); |
| } |
| <span class="kw">let </span>content; |
| <span class="kw">let _ </span>= <span class="macro">syn::parenthesized!</span>(content <span class="kw">in </span>input); |
| <span class="kw">let </span><span class="kw-2">mut </span>result = <span class="self">Self</span>::default(); |
| <span class="kw">let </span><span class="kw-2">mut </span>parse_one_arg = |
| || { |
| <span class="kw">let </span>lookahead = content.lookahead1(); |
| <span class="kw">if </span>lookahead.peek(kw::level) { |
| <span class="kw">if </span>result.level.is_some() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(content.error(<span class="string">"expected only a single `level` argument"</span>)); |
| } |
| result.level = <span class="prelude-val">Some</span>(content.parse()<span class="question-mark">?</span>); |
| } <span class="kw">else if </span>result.mode != FormatMode::default() { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(content.error(<span class="string">"expected only a single format argument"</span>)); |
| } <span class="kw">else if let </span><span class="prelude-val">Some</span>(ident) = content.parse::<<span class="prelude-ty">Option</span><Ident>>()<span class="question-mark">? </span>{ |
| <span class="kw">match </span>ident.to_string().as_str() { |
| <span class="string">"Debug" </span>=> result.mode = FormatMode::Debug, |
| <span class="string">"Display" </span>=> result.mode = FormatMode::Display, |
| <span class="kw">_ </span>=> <span class="kw">return </span><span class="prelude-val">Err</span>(syn::Error::new( |
| ident.span(), |
| <span class="string">"unknown event formatting mode, expected either `Debug` or `Display`"</span>, |
| )), |
| } |
| } |
| <span class="prelude-val">Ok</span>(()) |
| }; |
| parse_one_arg()<span class="question-mark">?</span>; |
| <span class="kw">if </span>!content.is_empty() { |
| <span class="kw">if </span>content.lookahead1().peek(<span class="macro">Token!</span>[,]) { |
| <span class="kw">let _ </span>= content.parse::<<span class="macro">Token!</span>[,]>()<span class="question-mark">?</span>; |
| parse_one_arg()<span class="question-mark">?</span>; |
| } <span class="kw">else </span>{ |
| <span class="kw">return </span><span class="prelude-val">Err</span>(content.error(<span class="string">"expected `,` or `)`"</span>)); |
| } |
| } |
| <span class="prelude-val">Ok</span>(result) |
| } |
| } |
| |
| <span class="kw">struct </span>StrArg<T> { |
| value: LitStr, |
| _p: std::marker::PhantomData<T>, |
| } |
| |
| <span class="kw">impl</span><T: Parse> Parse <span class="kw">for </span>StrArg<T> { |
| <span class="kw">fn </span>parse(input: ParseStream<<span class="lifetime">'_</span>>) -> syn::Result<<span class="self">Self</span>> { |
| <span class="kw">let _ </span>= input.parse::<T>()<span class="question-mark">?</span>; |
| <span class="kw">let _ </span>= input.parse::<<span class="macro">Token!</span>[=]>()<span class="question-mark">?</span>; |
| <span class="kw">let </span>value = input.parse()<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(<span class="self">Self </span>{ |
| value, |
| _p: std::marker::PhantomData, |
| }) |
| } |
| } |
| |
| <span class="kw">struct </span>ExprArg<T> { |
| value: Expr, |
| _p: std::marker::PhantomData<T>, |
| } |
| |
| <span class="kw">impl</span><T: Parse> Parse <span class="kw">for </span>ExprArg<T> { |
| <span class="kw">fn </span>parse(input: ParseStream<<span class="lifetime">'_</span>>) -> syn::Result<<span class="self">Self</span>> { |
| <span class="kw">let _ </span>= input.parse::<T>()<span class="question-mark">?</span>; |
| <span class="kw">let _ </span>= input.parse::<<span class="macro">Token!</span>[=]>()<span class="question-mark">?</span>; |
| <span class="kw">let </span>value = input.parse()<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(<span class="self">Self </span>{ |
| value, |
| _p: std::marker::PhantomData, |
| }) |
| } |
| } |
| |
| <span class="kw">struct </span>Skips(HashSet<Ident>); |
| |
| <span class="kw">impl </span>Parse <span class="kw">for </span>Skips { |
| <span class="kw">fn </span>parse(input: ParseStream<<span class="lifetime">'_</span>>) -> syn::Result<<span class="self">Self</span>> { |
| <span class="kw">let _ </span>= input.parse::<kw::skip>(); |
| <span class="kw">let </span>content; |
| <span class="kw">let _ </span>= <span class="macro">syn::parenthesized!</span>(content <span class="kw">in </span>input); |
| <span class="kw">let </span>names = content.parse_terminated(Ident::parse_any, <span class="macro">Token!</span>[,])<span class="question-mark">?</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>skips = HashSet::new(); |
| <span class="kw">for </span>name <span class="kw">in </span>names { |
| <span class="kw">if </span>skips.contains(<span class="kw-2">&</span>name) { |
| <span class="kw">return </span><span class="prelude-val">Err</span>(syn::Error::new( |
| name.span(), |
| <span class="string">"tried to skip the same field twice"</span>, |
| )); |
| } <span class="kw">else </span>{ |
| skips.insert(name); |
| } |
| } |
| <span class="prelude-val">Ok</span>(<span class="self">Self</span>(skips)) |
| } |
| } |
| |
| <span class="attribute">#[derive(Clone, Debug, Hash, PartialEq, Eq)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>FormatMode { |
| Default, |
| Display, |
| Debug, |
| } |
| |
| <span class="kw">impl </span>Default <span class="kw">for </span>FormatMode { |
| <span class="kw">fn </span>default() -> <span class="self">Self </span>{ |
| FormatMode::Default |
| } |
| } |
| |
| <span class="attribute">#[derive(Clone, Debug)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>Fields(<span class="kw">pub</span>(<span class="kw">crate</span>) Punctuated<Field, <span class="macro">Token!</span>[,]>); |
| |
| <span class="attribute">#[derive(Clone, Debug)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>Field { |
| <span class="kw">pub</span>(<span class="kw">crate</span>) name: Punctuated<Ident, <span class="macro">Token!</span>[.]>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) value: <span class="prelude-ty">Option</span><Expr>, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) kind: FieldKind, |
| } |
| |
| <span class="attribute">#[derive(Clone, Debug, Eq, PartialEq)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>FieldKind { |
| Debug, |
| Display, |
| Value, |
| } |
| |
| <span class="kw">impl </span>Parse <span class="kw">for </span>Fields { |
| <span class="kw">fn </span>parse(input: ParseStream<<span class="lifetime">'_</span>>) -> syn::Result<<span class="self">Self</span>> { |
| <span class="kw">let _ </span>= input.parse::<kw::fields>(); |
| <span class="kw">let </span>content; |
| <span class="kw">let _ </span>= <span class="macro">syn::parenthesized!</span>(content <span class="kw">in </span>input); |
| <span class="kw">let </span>fields = content.parse_terminated(Field::parse, <span class="macro">Token!</span>[,])<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(<span class="self">Self</span>(fields)) |
| } |
| } |
| |
| <span class="kw">impl </span>ToTokens <span class="kw">for </span>Fields { |
| <span class="kw">fn </span>to_tokens(<span class="kw-2">&</span><span class="self">self</span>, tokens: <span class="kw-2">&mut </span>TokenStream) { |
| <span class="self">self</span>.<span class="number">0</span>.to_tokens(tokens) |
| } |
| } |
| |
| <span class="kw">impl </span>Parse <span class="kw">for </span>Field { |
| <span class="kw">fn </span>parse(input: ParseStream<<span class="lifetime">'_</span>>) -> syn::Result<<span class="self">Self</span>> { |
| <span class="kw">let </span><span class="kw-2">mut </span>kind = FieldKind::Value; |
| <span class="kw">if </span>input.peek(<span class="macro">Token!</span>[%]) { |
| input.parse::<<span class="macro">Token!</span>[%]>()<span class="question-mark">?</span>; |
| kind = FieldKind::Display; |
| } <span class="kw">else if </span>input.peek(<span class="macro">Token!</span>[<span class="question-mark">?</span>]) { |
| input.parse::<<span class="macro">Token!</span>[<span class="question-mark">?</span>]>()<span class="question-mark">?</span>; |
| kind = FieldKind::Debug; |
| }; |
| <span class="kw">let </span>name = Punctuated::parse_separated_nonempty_with(input, Ident::parse_any)<span class="question-mark">?</span>; |
| <span class="kw">let </span>value = <span class="kw">if </span>input.peek(<span class="macro">Token!</span>[=]) { |
| input.parse::<<span class="macro">Token!</span>[=]>()<span class="question-mark">?</span>; |
| <span class="kw">if </span>input.peek(<span class="macro">Token!</span>[%]) { |
| input.parse::<<span class="macro">Token!</span>[%]>()<span class="question-mark">?</span>; |
| kind = FieldKind::Display; |
| } <span class="kw">else if </span>input.peek(<span class="macro">Token!</span>[<span class="question-mark">?</span>]) { |
| input.parse::<<span class="macro">Token!</span>[<span class="question-mark">?</span>]>()<span class="question-mark">?</span>; |
| kind = FieldKind::Debug; |
| }; |
| <span class="prelude-val">Some</span>(input.parse()<span class="question-mark">?</span>) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">None |
| </span>}; |
| <span class="prelude-val">Ok</span>(<span class="self">Self </span>{ name, value, kind }) |
| } |
| } |
| |
| <span class="kw">impl </span>ToTokens <span class="kw">for </span>Field { |
| <span class="kw">fn </span>to_tokens(<span class="kw-2">&</span><span class="self">self</span>, tokens: <span class="kw-2">&mut </span>TokenStream) { |
| <span class="kw">if let </span><span class="prelude-val">Some</span>(<span class="kw-2">ref </span>value) = <span class="self">self</span>.value { |
| <span class="kw">let </span>name = <span class="kw-2">&</span><span class="self">self</span>.name; |
| <span class="kw">let </span>kind = <span class="kw-2">&</span><span class="self">self</span>.kind; |
| tokens.extend(<span class="macro">quote! </span>{ |
| #name = #kind #value |
| }) |
| } <span class="kw">else if </span><span class="self">self</span>.kind == FieldKind::Value { |
| <span class="comment">// XXX(eliza): I don't like that fields without values produce |
| // empty fields rather than local variable shorthand...but, |
| // we've released a version where field names without values in |
| // `instrument` produce empty field values, so changing it now |
| // is a breaking change. agh. |
| </span><span class="kw">let </span>name = <span class="kw-2">&</span><span class="self">self</span>.name; |
| tokens.extend(<span class="macro">quote!</span>(#name = tracing::field::Empty)) |
| } <span class="kw">else </span>{ |
| <span class="self">self</span>.kind.to_tokens(tokens); |
| <span class="self">self</span>.name.to_tokens(tokens); |
| } |
| } |
| } |
| |
| <span class="kw">impl </span>ToTokens <span class="kw">for </span>FieldKind { |
| <span class="kw">fn </span>to_tokens(<span class="kw-2">&</span><span class="self">self</span>, tokens: <span class="kw-2">&mut </span>TokenStream) { |
| <span class="kw">match </span><span class="self">self </span>{ |
| FieldKind::Debug => tokens.extend(<span class="macro">quote! </span>{ <span class="question-mark">? </span>}), |
| FieldKind::Display => tokens.extend(<span class="macro">quote! </span>{ % }), |
| <span class="kw">_ </span>=> {} |
| } |
| } |
| } |
| |
| <span class="attribute">#[derive(Clone, Debug)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>Level { |
| Trace, |
| Debug, |
| Info, |
| Warn, |
| Error, |
| Path(Path), |
| } |
| |
| <span class="kw">impl </span>Parse <span class="kw">for </span>Level { |
| <span class="kw">fn </span>parse(input: ParseStream<<span class="lifetime">'_</span>>) -> syn::Result<<span class="self">Self</span>> { |
| <span class="kw">let _ </span>= input.parse::<kw::level>()<span class="question-mark">?</span>; |
| <span class="kw">let _ </span>= input.parse::<<span class="macro">Token!</span>[=]>()<span class="question-mark">?</span>; |
| <span class="kw">let </span>lookahead = input.lookahead1(); |
| <span class="kw">if </span>lookahead.peek(LitStr) { |
| <span class="kw">let </span>str: LitStr = input.parse()<span class="question-mark">?</span>; |
| <span class="kw">match </span>str.value() { |
| s <span class="kw">if </span>s.eq_ignore_ascii_case(<span class="string">"trace"</span>) => <span class="prelude-val">Ok</span>(Level::Trace), |
| s <span class="kw">if </span>s.eq_ignore_ascii_case(<span class="string">"debug"</span>) => <span class="prelude-val">Ok</span>(Level::Debug), |
| s <span class="kw">if </span>s.eq_ignore_ascii_case(<span class="string">"info"</span>) => <span class="prelude-val">Ok</span>(Level::Info), |
| s <span class="kw">if </span>s.eq_ignore_ascii_case(<span class="string">"warn"</span>) => <span class="prelude-val">Ok</span>(Level::Warn), |
| s <span class="kw">if </span>s.eq_ignore_ascii_case(<span class="string">"error"</span>) => <span class="prelude-val">Ok</span>(Level::Error), |
| <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(input.error( |
| <span class="string">"unknown verbosity level, expected one of \"trace\", \ |
| \"debug\", \"info\", \"warn\", or \"error\", or a number 1-5"</span>, |
| )), |
| } |
| } <span class="kw">else if </span>lookahead.peek(LitInt) { |
| <span class="kw">fn </span>is_level(lit: <span class="kw-2">&</span>LitInt, expected: u64) -> bool { |
| <span class="kw">match </span>lit.base10_parse::<u64>() { |
| <span class="prelude-val">Ok</span>(value) => value == expected, |
| <span class="prelude-val">Err</span>(<span class="kw">_</span>) => <span class="bool-val">false</span>, |
| } |
| } |
| <span class="kw">let </span>int: LitInt = input.parse()<span class="question-mark">?</span>; |
| <span class="kw">match </span><span class="kw-2">&</span>int { |
| i <span class="kw">if </span>is_level(i, <span class="number">1</span>) => <span class="prelude-val">Ok</span>(Level::Trace), |
| i <span class="kw">if </span>is_level(i, <span class="number">2</span>) => <span class="prelude-val">Ok</span>(Level::Debug), |
| i <span class="kw">if </span>is_level(i, <span class="number">3</span>) => <span class="prelude-val">Ok</span>(Level::Info), |
| i <span class="kw">if </span>is_level(i, <span class="number">4</span>) => <span class="prelude-val">Ok</span>(Level::Warn), |
| i <span class="kw">if </span>is_level(i, <span class="number">5</span>) => <span class="prelude-val">Ok</span>(Level::Error), |
| <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(input.error( |
| <span class="string">"unknown verbosity level, expected one of \"trace\", \ |
| \"debug\", \"info\", \"warn\", or \"error\", or a number 1-5"</span>, |
| )), |
| } |
| } <span class="kw">else if </span>lookahead.peek(Ident) { |
| <span class="prelude-val">Ok</span>(<span class="self">Self</span>::Path(input.parse()<span class="question-mark">?</span>)) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(lookahead.error()) |
| } |
| } |
| } |
| |
| <span class="kw">impl </span>ToTokens <span class="kw">for </span>Level { |
| <span class="kw">fn </span>to_tokens(<span class="kw-2">&</span><span class="self">self</span>, tokens: <span class="kw-2">&mut </span>TokenStream) { |
| <span class="kw">match </span><span class="self">self </span>{ |
| Level::Trace => tokens.extend(<span class="macro">quote!</span>(tracing::Level::TRACE)), |
| Level::Debug => tokens.extend(<span class="macro">quote!</span>(tracing::Level::DEBUG)), |
| Level::Info => tokens.extend(<span class="macro">quote!</span>(tracing::Level::INFO)), |
| Level::Warn => tokens.extend(<span class="macro">quote!</span>(tracing::Level::WARN)), |
| Level::Error => tokens.extend(<span class="macro">quote!</span>(tracing::Level::ERROR)), |
| Level::Path(<span class="kw-2">ref </span>pat) => tokens.extend(<span class="macro">quote!</span>(#pat)), |
| } |
| } |
| } |
| |
| <span class="kw">mod </span>kw { |
| <span class="macro">syn::custom_keyword!</span>(fields); |
| <span class="macro">syn::custom_keyword!</span>(skip); |
| <span class="macro">syn::custom_keyword!</span>(skip_all); |
| <span class="macro">syn::custom_keyword!</span>(level); |
| <span class="macro">syn::custom_keyword!</span>(target); |
| <span class="macro">syn::custom_keyword!</span>(parent); |
| <span class="macro">syn::custom_keyword!</span>(follows_from); |
| <span class="macro">syn::custom_keyword!</span>(name); |
| <span class="macro">syn::custom_keyword!</span>(err); |
| <span class="macro">syn::custom_keyword!</span>(ret); |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="tracing_attributes" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
