diff --git a/compiler/rustc_macros/src/query.rs b/compiler/rustc_macros/src/query.rs index a6912653368..52c93133f79 100644 --- a/compiler/rustc_macros/src/query.rs +++ b/compiler/rustc_macros/src/query.rs @@ -1,139 +1,17 @@ use proc_macro::TokenStream; -use proc_macro2::{Delimiter, TokenTree}; use quote::{quote, quote_spanned}; use syn::parse::{Parse, ParseStream, Result}; use syn::punctuated::Punctuated; use syn::spanned::Spanned; use syn::{ - braced, parenthesized, parse_macro_input, parse_quote, AttrStyle, Attribute, Block, Error, - Expr, Ident, ReturnType, Token, Type, + braced, parenthesized, parse_macro_input, parse_quote, token, AttrStyle, Attribute, Block, + Error, Expr, Ident, Pat, ReturnType, Token, Type, }; mod kw { syn::custom_keyword!(query); } -/// Ident or a wildcard `_`. -struct IdentOrWild(Ident); - -impl Parse for IdentOrWild { - fn parse(input: ParseStream<'_>) -> Result { - Ok(if input.peek(Token![_]) { - let underscore = input.parse::()?; - IdentOrWild(Ident::new("_", underscore.span())) - } else { - IdentOrWild(input.parse()?) - }) - } -} - -/// A modifier for a query -enum QueryModifier { - /// The description of the query. - Desc(Option, Punctuated), - - /// Use this type for the in-memory cache. - Storage(Type), - - /// Cache the query to disk if the `Expr` returns true. - Cache(Option, Block), - - /// Custom code to load the query from disk. - LoadCached(Ident, Ident, Block), - - /// A cycle error for this query aborting the compilation with a fatal error. - FatalCycle(Ident), - - /// A cycle error results in a delay_bug call - CycleDelayBug(Ident), - - /// Don't hash the result, instead just mark a query red if it runs - NoHash(Ident), - - /// Generate a dep node based on the dependencies of the query - Anon(Ident), - - /// Always evaluate the query, ignoring its dependencies - EvalAlways(Ident), - - /// Use a separate query provider for local and extern crates - SeparateProvideExtern(Ident), - - /// Always remap the ParamEnv's constness before hashing and passing to the query provider - RemapEnvConstness(Ident), -} - -impl Parse for QueryModifier { - fn parse(input: ParseStream<'_>) -> Result { - let modifier: Ident = input.parse()?; - if modifier == "desc" { - // Parse a description modifier like: - // `desc { |tcx| "foo {}", tcx.item_path(key) }` - let attr_content; - braced!(attr_content in input); - let tcx = if attr_content.peek(Token![|]) { - attr_content.parse::()?; - let tcx = attr_content.parse()?; - attr_content.parse::()?; - Some(tcx) - } else { - None - }; - let desc = attr_content.parse_terminated(Expr::parse)?; - Ok(QueryModifier::Desc(tcx, desc)) - } else if modifier == "cache_on_disk_if" { - // Parse a cache modifier like: - // `cache(tcx, value) { |tcx| key.is_local() }` - let has_args = if let TokenTree::Group(group) = input.fork().parse()? { - group.delimiter() == Delimiter::Parenthesis - } else { - false - }; - let args = if has_args { - let args; - parenthesized!(args in input); - let tcx = args.parse()?; - Some(tcx) - } else { - None - }; - let block = input.parse()?; - Ok(QueryModifier::Cache(args, block)) - } else if modifier == "load_cached" { - // Parse a load_cached modifier like: - // `load_cached(tcx, id) { tcx.on_disk_cache.try_load_query_result(tcx, id) }` - let args; - parenthesized!(args in input); - let tcx = args.parse()?; - args.parse::()?; - let id = args.parse()?; - let block = input.parse()?; - Ok(QueryModifier::LoadCached(tcx, id, block)) - } else if modifier == "storage" { - let args; - parenthesized!(args in input); - let ty = args.parse()?; - Ok(QueryModifier::Storage(ty)) - } else if modifier == "fatal_cycle" { - Ok(QueryModifier::FatalCycle(modifier)) - } else if modifier == "cycle_delay_bug" { - Ok(QueryModifier::CycleDelayBug(modifier)) - } else if modifier == "no_hash" { - Ok(QueryModifier::NoHash(modifier)) - } else if modifier == "anon" { - Ok(QueryModifier::Anon(modifier)) - } else if modifier == "eval_always" { - Ok(QueryModifier::EvalAlways(modifier)) - } else if modifier == "separate_provide_extern" { - Ok(QueryModifier::SeparateProvideExtern(modifier)) - } else if modifier == "remap_env_constness" { - Ok(QueryModifier::RemapEnvConstness(modifier)) - } else { - Err(Error::new(modifier.span(), "unknown query modifier")) - } - } -} - /// Ensures only doc comment attributes are used fn check_attributes(attrs: Vec) -> Result> { let inner = |attr: Attribute| { @@ -154,16 +32,16 @@ fn check_attributes(attrs: Vec) -> Result> { /// A compiler query. `query ... { ... }` struct Query { doc_comments: Vec, - modifiers: List, + modifiers: QueryModifiers, name: Ident, - key: IdentOrWild, + key: Pat, arg: Type, result: ReturnType, } impl Parse for Query { fn parse(input: ParseStream<'_>) -> Result { - let doc_comments = check_attributes(input.call(Attribute::parse_outer)?)?; + let mut doc_comments = check_attributes(input.call(Attribute::parse_outer)?)?; // Parse the query declaration. Like `query type_of(key: DefId) -> Ty<'tcx>` input.parse::()?; @@ -178,7 +56,13 @@ fn parse(input: ParseStream<'_>) -> Result { // Parse the query modifiers let content; braced!(content in input); - let modifiers = content.parse()?; + let modifiers = parse_query_modifiers(&content)?; + + // If there are no doc-comments, give at least some idea of what + // it does by showing the query description. + if doc_comments.is_empty() { + doc_comments.push(doc_comment_from_desc(&modifiers.desc.1)?); + } Ok(Query { doc_comments, modifiers, name, key, arg, result }) } @@ -205,7 +89,7 @@ struct QueryModifiers { storage: Option, /// Cache the query to disk if the `Block` returns true. - cache: Option<(Option, Block)>, + cache: Option<(Option, Block)>, /// Custom code to load the query from disk. load_cached: Option<(Ident, Ident, Block)>, @@ -232,8 +116,7 @@ struct QueryModifiers { remap_env_constness: Option, } -/// Process query modifiers into a struct, erroring on duplicates -fn process_modifiers(query: &mut Query) -> QueryModifiers { +fn parse_query_modifiers(input: ParseStream<'_>) -> Result { let mut load_cached = None; let mut storage = None; let mut cache = None; @@ -245,117 +128,84 @@ fn process_modifiers(query: &mut Query) -> QueryModifiers { let mut eval_always = None; let mut separate_provide_extern = None; let mut remap_env_constness = None; - for modifier in query.modifiers.0.drain(..) { - match modifier { - QueryModifier::LoadCached(tcx, id, block) => { - if load_cached.is_some() { - panic!("duplicate modifier `load_cached` for query `{}`", query.name); + + while !input.is_empty() { + let modifier: Ident = input.parse()?; + + macro_rules! try_insert { + ($name:ident = $expr:expr) => { + if $name.is_some() { + return Err(Error::new(modifier.span(), "duplicate modifier")); } - load_cached = Some((tcx, id, block)); - } - QueryModifier::Storage(ty) => { - if storage.is_some() { - panic!("duplicate modifier `storage` for query `{}`", query.name); - } - storage = Some(ty); - } - QueryModifier::Cache(args, expr) => { - if cache.is_some() { - panic!("duplicate modifier `cache` for query `{}`", query.name); - } - cache = Some((args, expr)); - } - QueryModifier::Desc(tcx, list) => { - if desc.is_some() { - panic!("duplicate modifier `desc` for query `{}`", query.name); - } - // If there are no doc-comments, give at least some idea of what - // it does by showing the query description. - if query.doc_comments.is_empty() { - use ::syn::*; - let mut list = list.iter(); - let format_str: String = match list.next() { - Some(&Expr::Lit(ExprLit { lit: Lit::Str(ref lit_str), .. })) => { - lit_str.value().replace("`{}`", "{}") // We add them later anyways for consistency - } - _ => panic!("Expected a string literal"), - }; - let mut fmt_fragments = format_str.split("{}"); - let mut doc_string = fmt_fragments.next().unwrap().to_string(); - list.map(::quote::ToTokens::to_token_stream).zip(fmt_fragments).for_each( - |(tts, next_fmt_fragment)| { - use ::core::fmt::Write; - write!( - &mut doc_string, - " `{}` {}", - tts.to_string().replace(" . ", "."), - next_fmt_fragment, - ) - .unwrap(); - }, - ); - let doc_string = format!( - "[query description - consider adding a doc-comment!] {}", - doc_string - ); - let comment = parse_quote! { - #[doc = #doc_string] - }; - query.doc_comments.push(comment); - } - desc = Some((tcx, list)); - } - QueryModifier::FatalCycle(ident) => { - if fatal_cycle.is_some() { - panic!("duplicate modifier `fatal_cycle` for query `{}`", query.name); - } - fatal_cycle = Some(ident); - } - QueryModifier::CycleDelayBug(ident) => { - if cycle_delay_bug.is_some() { - panic!("duplicate modifier `cycle_delay_bug` for query `{}`", query.name); - } - cycle_delay_bug = Some(ident); - } - QueryModifier::NoHash(ident) => { - if no_hash.is_some() { - panic!("duplicate modifier `no_hash` for query `{}`", query.name); - } - no_hash = Some(ident); - } - QueryModifier::Anon(ident) => { - if anon.is_some() { - panic!("duplicate modifier `anon` for query `{}`", query.name); - } - anon = Some(ident); - } - QueryModifier::EvalAlways(ident) => { - if eval_always.is_some() { - panic!("duplicate modifier `eval_always` for query `{}`", query.name); - } - eval_always = Some(ident); - } - QueryModifier::SeparateProvideExtern(ident) => { - if separate_provide_extern.is_some() { - panic!( - "duplicate modifier `separate_provide_extern` for query `{}`", - query.name - ); - } - separate_provide_extern = Some(ident); - } - QueryModifier::RemapEnvConstness(ident) => { - if remap_env_constness.is_some() { - panic!("duplicate modifier `remap_env_constness` for query `{}`", query.name); - } - remap_env_constness = Some(ident) - } + $name = Some($expr); + }; + } + + if modifier == "desc" { + // Parse a description modifier like: + // `desc { |tcx| "foo {}", tcx.item_path(key) }` + let attr_content; + braced!(attr_content in input); + let tcx = if attr_content.peek(Token![|]) { + attr_content.parse::()?; + let tcx = attr_content.parse()?; + attr_content.parse::()?; + Some(tcx) + } else { + None + }; + let list = attr_content.parse_terminated(Expr::parse)?; + try_insert!(desc = (tcx, list)); + } else if modifier == "cache_on_disk_if" { + // Parse a cache modifier like: + // `cache(tcx) { |tcx| key.is_local() }` + let args = if input.peek(token::Paren) { + let args; + parenthesized!(args in input); + let tcx = args.parse()?; + Some(tcx) + } else { + None + }; + let block = input.parse()?; + try_insert!(cache = (args, block)); + } else if modifier == "load_cached" { + // Parse a load_cached modifier like: + // `load_cached(tcx, id) { tcx.on_disk_cache.try_load_query_result(tcx, id) }` + let args; + parenthesized!(args in input); + let tcx = args.parse()?; + args.parse::()?; + let id = args.parse()?; + let block = input.parse()?; + try_insert!(load_cached = (tcx, id, block)); + } else if modifier == "storage" { + let args; + parenthesized!(args in input); + let ty = args.parse()?; + try_insert!(storage = ty); + } else if modifier == "fatal_cycle" { + try_insert!(fatal_cycle = modifier); + } else if modifier == "cycle_delay_bug" { + try_insert!(cycle_delay_bug = modifier); + } else if modifier == "no_hash" { + try_insert!(no_hash = modifier); + } else if modifier == "anon" { + try_insert!(anon = modifier); + } else if modifier == "eval_always" { + try_insert!(eval_always = modifier); + } else if modifier == "separate_provide_extern" { + try_insert!(separate_provide_extern = modifier); + } else if modifier == "remap_env_constness" { + try_insert!(remap_env_constness = modifier); + } else { + return Err(Error::new(modifier.span(), "unknown query modifier")); } } - let desc = desc.unwrap_or_else(|| { - panic!("no description provided for query `{}`", query.name); - }); - QueryModifiers { + let Some(desc) = desc else { + return Err(input.error("no description provided")); + }; + Ok(QueryModifiers { load_cached, storage, cache, @@ -367,17 +217,41 @@ fn process_modifiers(query: &mut Query) -> QueryModifiers { eval_always, separate_provide_extern, remap_env_constness, - } + }) +} + +fn doc_comment_from_desc(list: &Punctuated) -> Result { + use ::syn::*; + let mut iter = list.iter(); + let format_str: String = match iter.next() { + Some(&Expr::Lit(ExprLit { lit: Lit::Str(ref lit_str), .. })) => { + lit_str.value().replace("`{}`", "{}") // We add them later anyways for consistency + } + _ => return Err(Error::new(list.span(), "Expected a string literal")), + }; + let mut fmt_fragments = format_str.split("{}"); + let mut doc_string = fmt_fragments.next().unwrap().to_string(); + iter.map(::quote::ToTokens::to_token_stream).zip(fmt_fragments).for_each( + |(tts, next_fmt_fragment)| { + use ::core::fmt::Write; + write!( + &mut doc_string, + " `{}` {}", + tts.to_string().replace(" . ", "."), + next_fmt_fragment, + ) + .unwrap(); + }, + ); + let doc_string = format!("[query description - consider adding a doc-comment!] {}", doc_string); + Ok(parse_quote! { #[doc = #doc_string] }) } /// Add the impl of QueryDescription for the query to `impls` if one is requested -fn add_query_description_impl( - query: &Query, - modifiers: QueryModifiers, - impls: &mut proc_macro2::TokenStream, -) { +fn add_query_description_impl(query: &Query, impls: &mut proc_macro2::TokenStream) { let name = &query.name; - let key = &query.key.0; + let key = &query.key; + let modifiers = &query.modifiers; // Find out if we should cache the query on disk let cache = if let Some((args, expr)) = modifiers.cache.as_ref() { @@ -395,13 +269,7 @@ fn add_query_description_impl( } }; - let tcx = args - .as_ref() - .map(|t| { - let t = &t.0; - quote! { #t } - }) - .unwrap_or_else(|| quote! { _ }); + let tcx = args.as_ref().map(|t| quote! { #t }).unwrap_or_else(|| quote! { _ }); // expr is a `Block`, meaning that `{ #expr }` gets expanded // to `{ { stmts... } }`, which triggers the `unused_braces` lint. quote! { @@ -427,7 +295,7 @@ fn cache_on_disk(_: TyCtxt<'tcx>, _: &Self::Key) -> bool { } }; - let (tcx, desc) = modifiers.desc; + let (tcx, desc) = &modifiers.desc; let tcx = tcx.as_ref().map_or_else(|| quote! { _ }, |t| quote! { #t }); let desc = quote! { @@ -456,10 +324,8 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { let mut dep_node_def_stream = quote! {}; let mut cached_queries = quote! {}; - for mut query in queries.0 { - let modifiers = process_modifiers(&mut query); - let name = &query.name; - let arg = &query.arg; + for query in queries.0 { + let Query { name, arg, modifiers, .. } = &query; let result_full = &query.result; let result = match query.result { ReturnType::Default => quote! { -> () }, @@ -528,7 +394,7 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { [#attribute_stream] #name(#arg), }); - add_query_description_impl(&query, modifiers, &mut query_description_stream); + add_query_description_impl(&query, &mut query_description_stream); } TokenStream::from(quote! { @@ -539,7 +405,6 @@ macro_rules! rustc_query_append { $($other)* #query_stream - } } }