diff options
Diffstat (limited to 'third_party/rust/tokio-macros/src')
| -rw-r--r-- | third_party/rust/tokio-macros/src/entry.rs | 494 | ||||
| -rw-r--r-- | third_party/rust/tokio-macros/src/lib.rs | 483 | ||||
| -rw-r--r-- | third_party/rust/tokio-macros/src/select.rs | 110 |
3 files changed, 1087 insertions, 0 deletions
diff --git a/third_party/rust/tokio-macros/src/entry.rs b/third_party/rust/tokio-macros/src/entry.rs new file mode 100644 index 0000000000..6460e70afa --- /dev/null +++ b/third_party/rust/tokio-macros/src/entry.rs @@ -0,0 +1,494 @@ +use proc_macro::TokenStream; +use proc_macro2::{Ident, Span}; +use quote::{quote, quote_spanned, ToTokens}; +use syn::parse::Parser; + +// syn::AttributeArgs does not implement syn::Parse +type AttributeArgs = syn::punctuated::Punctuated<syn::NestedMeta, syn::Token![,]>; + +#[derive(Clone, Copy, PartialEq)] +enum RuntimeFlavor { + CurrentThread, + Threaded, +} + +impl RuntimeFlavor { + fn from_str(s: &str) -> Result<RuntimeFlavor, String> { + match s { + "current_thread" => Ok(RuntimeFlavor::CurrentThread), + "multi_thread" => Ok(RuntimeFlavor::Threaded), + "single_thread" => Err("The single threaded runtime flavor is called `current_thread`.".to_string()), + "basic_scheduler" => Err("The `basic_scheduler` runtime flavor has been renamed to `current_thread`.".to_string()), + "threaded_scheduler" => Err("The `threaded_scheduler` runtime flavor has been renamed to `multi_thread`.".to_string()), + _ => Err(format!("No such runtime flavor `{}`. The runtime flavors are `current_thread` and `multi_thread`.", s)), + } + } +} + +struct FinalConfig { + flavor: RuntimeFlavor, + worker_threads: Option<usize>, + start_paused: Option<bool>, + crate_name: Option<String>, +} + +/// Config used in case of the attribute not being able to build a valid config +const DEFAULT_ERROR_CONFIG: FinalConfig = FinalConfig { + flavor: RuntimeFlavor::CurrentThread, + worker_threads: None, + start_paused: None, + crate_name: None, +}; + +struct Configuration { + rt_multi_thread_available: bool, + default_flavor: RuntimeFlavor, + flavor: Option<RuntimeFlavor>, + worker_threads: Option<(usize, Span)>, + start_paused: Option<(bool, Span)>, + is_test: bool, + crate_name: Option<String>, +} + +impl Configuration { + fn new(is_test: bool, rt_multi_thread: bool) -> Self { + Configuration { + rt_multi_thread_available: rt_multi_thread, + default_flavor: match is_test { + true => RuntimeFlavor::CurrentThread, + false => RuntimeFlavor::Threaded, + }, + flavor: None, + worker_threads: None, + start_paused: None, + is_test, + crate_name: None, + } + } + + fn set_flavor(&mut self, runtime: syn::Lit, span: Span) -> Result<(), syn::Error> { + if self.flavor.is_some() { + return Err(syn::Error::new(span, "`flavor` set multiple times.")); + } + + let runtime_str = parse_string(runtime, span, "flavor")?; + let runtime = + RuntimeFlavor::from_str(&runtime_str).map_err(|err| syn::Error::new(span, err))?; + self.flavor = Some(runtime); + Ok(()) + } + + fn set_worker_threads( + &mut self, + worker_threads: syn::Lit, + span: Span, + ) -> Result<(), syn::Error> { + if self.worker_threads.is_some() { + return Err(syn::Error::new( + span, + "`worker_threads` set multiple times.", + )); + } + + let worker_threads = parse_int(worker_threads, span, "worker_threads")?; + if worker_threads == 0 { + return Err(syn::Error::new(span, "`worker_threads` may not be 0.")); + } + self.worker_threads = Some((worker_threads, span)); + Ok(()) + } + + fn set_start_paused(&mut self, start_paused: syn::Lit, span: Span) -> Result<(), syn::Error> { + if self.start_paused.is_some() { + return Err(syn::Error::new(span, "`start_paused` set multiple times.")); + } + + let start_paused = parse_bool(start_paused, span, "start_paused")?; + self.start_paused = Some((start_paused, span)); + Ok(()) + } + + fn set_crate_name(&mut self, name: syn::Lit, span: Span) -> Result<(), syn::Error> { + if self.crate_name.is_some() { + return Err(syn::Error::new(span, "`crate` set multiple times.")); + } + let name_ident = parse_ident(name, span, "crate")?; + self.crate_name = Some(name_ident.to_string()); + Ok(()) + } + + fn macro_name(&self) -> &'static str { + if self.is_test { + "tokio::test" + } else { + "tokio::main" + } + } + + fn build(&self) -> Result<FinalConfig, syn::Error> { + let flavor = self.flavor.unwrap_or(self.default_flavor); + use RuntimeFlavor::*; + + let worker_threads = match (flavor, self.worker_threads) { + (CurrentThread, Some((_, worker_threads_span))) => { + let msg = format!( + "The `worker_threads` option requires the `multi_thread` runtime flavor. Use `#[{}(flavor = \"multi_thread\")]`", + self.macro_name(), + ); + return Err(syn::Error::new(worker_threads_span, msg)); + } + (CurrentThread, None) => None, + (Threaded, worker_threads) if self.rt_multi_thread_available => { + worker_threads.map(|(val, _span)| val) + } + (Threaded, _) => { + let msg = if self.flavor.is_none() { + "The default runtime flavor is `multi_thread`, but the `rt-multi-thread` feature is disabled." + } else { + "The runtime flavor `multi_thread` requires the `rt-multi-thread` feature." + }; + return Err(syn::Error::new(Span::call_site(), msg)); + } + }; + + let start_paused = match (flavor, self.start_paused) { + (Threaded, Some((_, start_paused_span))) => { + let msg = format!( + "The `start_paused` option requires the `current_thread` runtime flavor. Use `#[{}(flavor = \"current_thread\")]`", + self.macro_name(), + ); + return Err(syn::Error::new(start_paused_span, msg)); + } + (CurrentThread, Some((start_paused, _))) => Some(start_paused), + (_, None) => None, + }; + + Ok(FinalConfig { + crate_name: self.crate_name.clone(), + flavor, + worker_threads, + start_paused, + }) + } +} + +fn parse_int(int: syn::Lit, span: Span, field: &str) -> Result<usize, syn::Error> { + match int { + syn::Lit::Int(lit) => match lit.base10_parse::<usize>() { + Ok(value) => Ok(value), + Err(e) => Err(syn::Error::new( + span, + format!("Failed to parse value of `{}` as integer: {}", field, e), + )), + }, + _ => Err(syn::Error::new( + span, + format!("Failed to parse value of `{}` as integer.", field), + )), + } +} + +fn parse_string(int: syn::Lit, span: Span, field: &str) -> Result<String, syn::Error> { + match int { + syn::Lit::Str(s) => Ok(s.value()), + syn::Lit::Verbatim(s) => Ok(s.to_string()), + _ => Err(syn::Error::new( + span, + format!("Failed to parse value of `{}` as string.", field), + )), + } +} + +fn parse_ident(lit: syn::Lit, span: Span, field: &str) -> Result<Ident, syn::Error> { + match lit { + syn::Lit::Str(s) => { + let err = syn::Error::new( + span, + format!( + "Failed to parse value of `{}` as ident: \"{}\"", + field, + s.value() + ), + ); + let path = s.parse::<syn::Path>().map_err(|_| err.clone())?; + path.get_ident().cloned().ok_or(err) + } + _ => Err(syn::Error::new( + span, + format!("Failed to parse value of `{}` as ident.", field), + )), + } +} + +fn parse_bool(bool: syn::Lit, span: Span, field: &str) -> Result<bool, syn::Error> { + match bool { + syn::Lit::Bool(b) => Ok(b.value), + _ => Err(syn::Error::new( + span, + format!("Failed to parse value of `{}` as bool.", field), + )), + } +} + +fn build_config( + input: syn::ItemFn, + args: AttributeArgs, + is_test: bool, + rt_multi_thread: bool, +) -> Result<FinalConfig, syn::Error> { + if input.sig.asyncness.is_none() { + let msg = "the `async` keyword is missing from the function declaration"; + return Err(syn::Error::new_spanned(input.sig.fn_token, msg)); + } + + let mut config = Configuration::new(is_test, rt_multi_thread); + let macro_name = config.macro_name(); + + for arg in args { + match arg { + syn::NestedMeta::Meta(syn::Meta::NameValue(namevalue)) => { + let ident = namevalue + .path + .get_ident() + .ok_or_else(|| { + syn::Error::new_spanned(&namevalue, "Must have specified ident") + })? + .to_string() + .to_lowercase(); + match ident.as_str() { + "worker_threads" => { + config.set_worker_threads( + namevalue.lit.clone(), + syn::spanned::Spanned::span(&namevalue.lit), + )?; + } + "flavor" => { + config.set_flavor( + namevalue.lit.clone(), + syn::spanned::Spanned::span(&namevalue.lit), + )?; + } + "start_paused" => { + config.set_start_paused( + namevalue.lit.clone(), + syn::spanned::Spanned::span(&namevalue.lit), + )?; + } + "core_threads" => { + let msg = "Attribute `core_threads` is renamed to `worker_threads`"; + return Err(syn::Error::new_spanned(namevalue, msg)); + } + "crate" => { + config.set_crate_name( + namevalue.lit.clone(), + syn::spanned::Spanned::span(&namevalue.lit), + )?; + } + name => { + let msg = format!( + "Unknown attribute {} is specified; expected one of: `flavor`, `worker_threads`, `start_paused`, `crate`", + name, + ); + return Err(syn::Error::new_spanned(namevalue, msg)); + } + } + } + syn::NestedMeta::Meta(syn::Meta::Path(path)) => { + let name = path + .get_ident() + .ok_or_else(|| syn::Error::new_spanned(&path, "Must have specified ident"))? + .to_string() + .to_lowercase(); + let msg = match name.as_str() { + "threaded_scheduler" | "multi_thread" => { + format!( + "Set the runtime flavor with #[{}(flavor = \"multi_thread\")].", + macro_name + ) + } + "basic_scheduler" | "current_thread" | "single_threaded" => { + format!( + "Set the runtime flavor with #[{}(flavor = \"current_thread\")].", + macro_name + ) + } + "flavor" | "worker_threads" | "start_paused" => { + format!("The `{}` attribute requires an argument.", name) + } + name => { + format!("Unknown attribute {} is specified; expected one of: `flavor`, `worker_threads`, `start_paused`, `crate`", name) + } + }; + return Err(syn::Error::new_spanned(path, msg)); + } + other => { + return Err(syn::Error::new_spanned( + other, + "Unknown attribute inside the macro", + )); + } + } + } + + config.build() +} + +fn parse_knobs(mut input: syn::ItemFn, is_test: bool, config: FinalConfig) -> TokenStream { + input.sig.asyncness = None; + + // If type mismatch occurs, the current rustc points to the last statement. + let (last_stmt_start_span, last_stmt_end_span) = { + let mut last_stmt = input + .block + .stmts + .last() + .map(ToTokens::into_token_stream) + .unwrap_or_default() + .into_iter(); + // `Span` on stable Rust has a limitation that only points to the first + // token, not the whole tokens. We can work around this limitation by + // using the first/last span of the tokens like + // `syn::Error::new_spanned` does. + let start = last_stmt.next().map_or_else(Span::call_site, |t| t.span()); + let end = last_stmt.last().map_or(start, |t| t.span()); + (start, end) + }; + + let crate_name = config.crate_name.as_deref().unwrap_or("tokio"); + + let crate_ident = Ident::new(crate_name, last_stmt_start_span); + + let mut rt = match config.flavor { + RuntimeFlavor::CurrentThread => quote_spanned! {last_stmt_start_span=> + #crate_ident::runtime::Builder::new_current_thread() + }, + RuntimeFlavor::Threaded => quote_spanned! {last_stmt_start_span=> + #crate_ident::runtime::Builder::new_multi_thread() + }, + }; + if let Some(v) = config.worker_threads { + rt = quote! { #rt.worker_threads(#v) }; + } + if let Some(v) = config.start_paused { + rt = quote! { #rt.start_paused(#v) }; + } + + let header = if is_test { + quote! { + #[::core::prelude::v1::test] + } + } else { + quote! {} + }; + + let body = &input.block; + let brace_token = input.block.brace_token; + let body_ident = quote! { body }; + let block_expr = quote_spanned! {last_stmt_end_span=> + #[allow(clippy::expect_used, clippy::diverging_sub_expression)] + { + return #rt + .enable_all() + .build() + .expect("Failed building the Runtime") + .block_on(#body_ident); + } + }; + + // For test functions pin the body to the stack and use `Pin<&mut dyn + // Future>` to reduce the amount of `Runtime::block_on` (and related + // functions) copies we generate during compilation due to the generic + // parameter `F` (the future to block on). This could have an impact on + // performance, but because it's only for testing it's unlikely to be very + // large. + // + // We don't do this for the main function as it should only be used once so + // there will be no benefit. + let body = if is_test { + let output_type = match &input.sig.output { + // For functions with no return value syn doesn't print anything, + // but that doesn't work as `Output` for our boxed `Future`, so + // default to `()` (the same type as the function output). + syn::ReturnType::Default => quote! { () }, + syn::ReturnType::Type(_, ret_type) => quote! { #ret_type }, + }; + quote! { + let body = async #body; + #crate_ident::pin!(body); + let body: ::std::pin::Pin<&mut dyn ::std::future::Future<Output = #output_type>> = body; + } + } else { + quote! { + let body = async #body; + } + }; + + input.block = syn::parse2(quote! { + { + #body + #block_expr + } + }) + .expect("Parsing failure"); + input.block.brace_token = brace_token; + + let result = quote! { + #header + #input + }; + + result.into() +} + +fn token_stream_with_error(mut tokens: TokenStream, error: syn::Error) -> TokenStream { + tokens.extend(TokenStream::from(error.into_compile_error())); + tokens +} + +#[cfg(not(test))] // Work around for rust-lang/rust#62127 +pub(crate) fn main(args: TokenStream, item: TokenStream, rt_multi_thread: bool) -> TokenStream { + // If any of the steps for this macro fail, we still want to expand to an item that is as close + // to the expected output as possible. This helps out IDEs such that completions and other + // related features keep working. + let input: syn::ItemFn = match syn::parse(item.clone()) { + Ok(it) => it, + Err(e) => return token_stream_with_error(item, e), + }; + + let config = if input.sig.ident == "main" && !input.sig.inputs.is_empty() { + let msg = "the main function cannot accept arguments"; + Err(syn::Error::new_spanned(&input.sig.ident, msg)) + } else { + AttributeArgs::parse_terminated + .parse(args) + .and_then(|args| build_config(input.clone(), args, false, rt_multi_thread)) + }; + + match config { + Ok(config) => parse_knobs(input, false, config), + Err(e) => token_stream_with_error(parse_knobs(input, false, DEFAULT_ERROR_CONFIG), e), + } +} + +pub(crate) fn test(args: TokenStream, item: TokenStream, rt_multi_thread: bool) -> TokenStream { + // If any of the steps for this macro fail, we still want to expand to an item that is as close + // to the expected output as possible. This helps out IDEs such that completions and other + // related features keep working. + let input: syn::ItemFn = match syn::parse(item.clone()) { + Ok(it) => it, + Err(e) => return token_stream_with_error(item, e), + }; + let config = if let Some(attr) = input.attrs.iter().find(|attr| attr.path.is_ident("test")) { + let msg = "second test attribute is supplied"; + Err(syn::Error::new_spanned(attr, msg)) + } else { + AttributeArgs::parse_terminated + .parse(args) + .and_then(|args| build_config(input.clone(), args, true, rt_multi_thread)) + }; + + match config { + Ok(config) => parse_knobs(input, true, config), + Err(e) => token_stream_with_error(parse_knobs(input, true, DEFAULT_ERROR_CONFIG), e), + } +} diff --git a/third_party/rust/tokio-macros/src/lib.rs b/third_party/rust/tokio-macros/src/lib.rs new file mode 100644 index 0000000000..34041afa4c --- /dev/null +++ b/third_party/rust/tokio-macros/src/lib.rs @@ -0,0 +1,483 @@ +#![allow(clippy::needless_doctest_main)] +#![warn( + missing_debug_implementations, + missing_docs, + rust_2018_idioms, + unreachable_pub +)] +#![doc(test( + no_crate_inject, + attr(deny(warnings, rust_2018_idioms), allow(dead_code, unused_variables)) +))] + +//! Macros for use with Tokio + +// This `extern` is required for older `rustc` versions but newer `rustc` +// versions warn about the unused `extern crate`. +#[allow(unused_extern_crates)] +extern crate proc_macro; + +mod entry; +mod select; + +use proc_macro::TokenStream; + +/// Marks async function to be executed by the selected runtime. This macro +/// helps set up a `Runtime` without requiring the user to use +/// [Runtime](../tokio/runtime/struct.Runtime.html) or +/// [Builder](../tokio/runtime/struct.Builder.html) directly. +/// +/// Note: This macro is designed to be simplistic and targets applications that +/// do not require a complex setup. If the provided functionality is not +/// sufficient, you may be interested in using +/// [Builder](../tokio/runtime/struct.Builder.html), which provides a more +/// powerful interface. +/// +/// Note: This macro can be used on any function and not just the `main` +/// function. Using it on a non-main function makes the function behave as if it +/// was synchronous by starting a new runtime each time it is called. If the +/// function is called often, it is preferable to create the runtime using the +/// runtime builder so the runtime can be reused across calls. +/// +/// # Multi-threaded runtime +/// +/// To use the multi-threaded runtime, the macro can be configured using +/// +/// ``` +/// #[tokio::main(flavor = "multi_thread", worker_threads = 10)] +/// # async fn main() {} +/// ``` +/// +/// The `worker_threads` option configures the number of worker threads, and +/// defaults to the number of cpus on the system. This is the default flavor. +/// +/// Note: The multi-threaded runtime requires the `rt-multi-thread` feature +/// flag. +/// +/// # Current thread runtime +/// +/// To use the single-threaded runtime known as the `current_thread` runtime, +/// the macro can be configured using +/// +/// ``` +/// #[tokio::main(flavor = "current_thread")] +/// # async fn main() {} +/// ``` +/// +/// ## Function arguments: +/// +/// Arguments are allowed for any functions aside from `main` which is special +/// +/// ## Usage +/// +/// ### Using the multi-thread runtime +/// +/// ```rust +/// #[tokio::main] +/// async fn main() { +/// println!("Hello world"); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::main]` +/// +/// ```rust +/// fn main() { +/// tokio::runtime::Builder::new_multi_thread() +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// println!("Hello world"); +/// }) +/// } +/// ``` +/// +/// ### Using current thread runtime +/// +/// The basic scheduler is single-threaded. +/// +/// ```rust +/// #[tokio::main(flavor = "current_thread")] +/// async fn main() { +/// println!("Hello world"); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::main]` +/// +/// ```rust +/// fn main() { +/// tokio::runtime::Builder::new_current_thread() +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// println!("Hello world"); +/// }) +/// } +/// ``` +/// +/// ### Set number of worker threads +/// +/// ```rust +/// #[tokio::main(worker_threads = 2)] +/// async fn main() { +/// println!("Hello world"); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::main]` +/// +/// ```rust +/// fn main() { +/// tokio::runtime::Builder::new_multi_thread() +/// .worker_threads(2) +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// println!("Hello world"); +/// }) +/// } +/// ``` +/// +/// ### Configure the runtime to start with time paused +/// +/// ```rust +/// #[tokio::main(flavor = "current_thread", start_paused = true)] +/// async fn main() { +/// println!("Hello world"); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::main]` +/// +/// ```rust +/// fn main() { +/// tokio::runtime::Builder::new_current_thread() +/// .enable_all() +/// .start_paused(true) +/// .build() +/// .unwrap() +/// .block_on(async { +/// println!("Hello world"); +/// }) +/// } +/// ``` +/// +/// Note that `start_paused` requires the `test-util` feature to be enabled. +/// +/// ### Rename package +/// +/// ```rust +/// use tokio as tokio1; +/// +/// #[tokio1::main(crate = "tokio1")] +/// async fn main() { +/// println!("Hello world"); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::main]` +/// +/// ```rust +/// use tokio as tokio1; +/// +/// fn main() { +/// tokio1::runtime::Builder::new_multi_thread() +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// println!("Hello world"); +/// }) +/// } +/// ``` +#[proc_macro_attribute] +#[cfg(not(test))] // Work around for rust-lang/rust#62127 +pub fn main(args: TokenStream, item: TokenStream) -> TokenStream { + entry::main(args, item, true) +} + +/// Marks async function to be executed by selected runtime. This macro helps set up a `Runtime` +/// without requiring the user to use [Runtime](../tokio/runtime/struct.Runtime.html) or +/// [Builder](../tokio/runtime/struct.builder.html) directly. +/// +/// ## Function arguments: +/// +/// Arguments are allowed for any functions aside from `main` which is special +/// +/// ## Usage +/// +/// ### Using default +/// +/// ```rust +/// #[tokio::main(flavor = "current_thread")] +/// async fn main() { +/// println!("Hello world"); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::main]` +/// +/// ```rust +/// fn main() { +/// tokio::runtime::Builder::new_current_thread() +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// println!("Hello world"); +/// }) +/// } +/// ``` +/// +/// ### Rename package +/// +/// ```rust +/// use tokio as tokio1; +/// +/// #[tokio1::main(crate = "tokio1")] +/// async fn main() { +/// println!("Hello world"); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::main]` +/// +/// ```rust +/// use tokio as tokio1; +/// +/// fn main() { +/// tokio1::runtime::Builder::new_multi_thread() +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// println!("Hello world"); +/// }) +/// } +/// ``` +#[proc_macro_attribute] +#[cfg(not(test))] // Work around for rust-lang/rust#62127 +pub fn main_rt(args: TokenStream, item: TokenStream) -> TokenStream { + entry::main(args, item, false) +} + +/// Marks async function to be executed by runtime, suitable to test environment. +/// This macro helps set up a `Runtime` without requiring the user to use +/// [Runtime](../tokio/runtime/struct.Runtime.html) or +/// [Builder](../tokio/runtime/struct.Builder.html) directly. +/// +/// Note: This macro is designed to be simplistic and targets applications that +/// do not require a complex setup. If the provided functionality is not +/// sufficient, you may be interested in using +/// [Builder](../tokio/runtime/struct.Builder.html), which provides a more +/// powerful interface. +/// +/// # Multi-threaded runtime +/// +/// To use the multi-threaded runtime, the macro can be configured using +/// +/// ```no_run +/// #[tokio::test(flavor = "multi_thread", worker_threads = 1)] +/// async fn my_test() { +/// assert!(true); +/// } +/// ``` +/// +/// The `worker_threads` option configures the number of worker threads, and +/// defaults to the number of cpus on the system. This is the default +/// flavor. +/// +/// Note: The multi-threaded runtime requires the `rt-multi-thread` feature +/// flag. +/// +/// # Current thread runtime +/// +/// The default test runtime is single-threaded. Each test gets a +/// separate current-thread runtime. +/// +/// ```no_run +/// #[tokio::test] +/// async fn my_test() { +/// assert!(true); +/// } +/// ``` +/// +/// ## Usage +/// +/// ### Using the multi-thread runtime +/// +/// ```no_run +/// #[tokio::test(flavor = "multi_thread")] +/// async fn my_test() { +/// assert!(true); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::test]` +/// +/// ```no_run +/// #[test] +/// fn my_test() { +/// tokio::runtime::Builder::new_multi_thread() +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// assert!(true); +/// }) +/// } +/// ``` +/// +/// ### Using current thread runtime +/// +/// ```no_run +/// #[tokio::test] +/// async fn my_test() { +/// assert!(true); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::test]` +/// +/// ```no_run +/// #[test] +/// fn my_test() { +/// tokio::runtime::Builder::new_current_thread() +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// assert!(true); +/// }) +/// } +/// ``` +/// +/// ### Set number of worker threads +/// +/// ```no_run +/// #[tokio::test(flavor ="multi_thread", worker_threads = 2)] +/// async fn my_test() { +/// assert!(true); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::test]` +/// +/// ```no_run +/// #[test] +/// fn my_test() { +/// tokio::runtime::Builder::new_multi_thread() +/// .worker_threads(2) +/// .enable_all() +/// .build() +/// .unwrap() +/// .block_on(async { +/// assert!(true); +/// }) +/// } +/// ``` +/// +/// ### Configure the runtime to start with time paused +/// +/// ```no_run +/// #[tokio::test(start_paused = true)] +/// async fn my_test() { +/// assert!(true); +/// } +/// ``` +/// +/// Equivalent code not using `#[tokio::test]` +/// +/// ```no_run +/// #[test] +/// fn my_test() { +/// tokio::runtime::Builder::new_current_thread() +/// .enable_all() +/// .start_paused(true) +/// .build() +/// .unwrap() +/// .block_on(async { +/// assert!(true); +/// }) +/// } +/// ``` +/// +/// Note that `start_paused` requires the `test-util` feature to be enabled. +/// +/// ### Rename package +/// +/// ```rust +/// use tokio as tokio1; +/// +/// #[tokio1::test(crate = "tokio1")] +/// async fn my_test() { +/// println!("Hello world"); +/// } +/// ``` +#[proc_macro_attribute] +pub fn test(args: TokenStream, item: TokenStream) -> TokenStream { + entry::test(args, item, true) +} + +/// Marks async function to be executed by runtime, suitable to test environment +/// +/// ## Usage +/// +/// ```no_run +/// #[tokio::test] +/// async fn my_test() { +/// assert!(true); +/// } +/// ``` +#[proc_macro_attribute] +pub fn test_rt(args: TokenStream, item: TokenStream) -> TokenStream { + entry::test(args, item, false) +} + +/// Always fails with the error message below. +/// ```text +/// The #[tokio::main] macro requires rt or rt-multi-thread. +/// ``` +#[proc_macro_attribute] +pub fn main_fail(_args: TokenStream, _item: TokenStream) -> TokenStream { + syn::Error::new( + proc_macro2::Span::call_site(), + "The #[tokio::main] macro requires rt or rt-multi-thread.", + ) + .to_compile_error() + .into() +} + +/// Always fails with the error message below. +/// ```text +/// The #[tokio::test] macro requires rt or rt-multi-thread. +/// ``` +#[proc_macro_attribute] +pub fn test_fail(_args: TokenStream, _item: TokenStream) -> TokenStream { + syn::Error::new( + proc_macro2::Span::call_site(), + "The #[tokio::test] macro requires rt or rt-multi-thread.", + ) + .to_compile_error() + .into() +} + +/// Implementation detail of the `select!` macro. This macro is **not** intended +/// to be used as part of the public API and is permitted to change. +#[proc_macro] +#[doc(hidden)] +pub fn select_priv_declare_output_enum(input: TokenStream) -> TokenStream { + select::declare_output_enum(input) +} + +/// Implementation detail of the `select!` macro. This macro is **not** intended +/// to be used as part of the public API and is permitted to change. +#[proc_macro] +#[doc(hidden)] +pub fn select_priv_clean_pattern(input: TokenStream) -> TokenStream { + select::clean_pattern_macro(input) +} diff --git a/third_party/rust/tokio-macros/src/select.rs b/third_party/rust/tokio-macros/src/select.rs new file mode 100644 index 0000000000..23e280a105 --- /dev/null +++ b/third_party/rust/tokio-macros/src/select.rs @@ -0,0 +1,110 @@ +use proc_macro::{TokenStream, TokenTree}; +use proc_macro2::Span; +use quote::quote; +use syn::Ident; + +pub(crate) fn declare_output_enum(input: TokenStream) -> TokenStream { + // passed in is: `(_ _ _)` with one `_` per branch + let branches = match input.into_iter().next() { + Some(TokenTree::Group(group)) => group.stream().into_iter().count(), + _ => panic!("unexpected macro input"), + }; + + let variants = (0..branches) + .map(|num| Ident::new(&format!("_{}", num), Span::call_site())) + .collect::<Vec<_>>(); + + // Use a bitfield to track which futures completed + let mask = Ident::new( + if branches <= 8 { + "u8" + } else if branches <= 16 { + "u16" + } else if branches <= 32 { + "u32" + } else if branches <= 64 { + "u64" + } else { + panic!("up to 64 branches supported"); + }, + Span::call_site(), + ); + + TokenStream::from(quote! { + pub(super) enum Out<#( #variants ),*> { + #( #variants(#variants), )* + // Include a `Disabled` variant signifying that all select branches + // failed to resolve. + Disabled, + } + + pub(super) type Mask = #mask; + }) +} + +pub(crate) fn clean_pattern_macro(input: TokenStream) -> TokenStream { + // If this isn't a pattern, we return the token stream as-is. The select! + // macro is using it in a location requiring a pattern, so an error will be + // emitted there. + let mut input: syn::Pat = match syn::parse(input.clone()) { + Ok(it) => it, + Err(_) => return input, + }; + + clean_pattern(&mut input); + quote::ToTokens::into_token_stream(input).into() +} + +// Removes any occurrences of ref or mut in the provided pattern. +fn clean_pattern(pat: &mut syn::Pat) { + match pat { + syn::Pat::Box(_box) => {} + syn::Pat::Lit(_literal) => {} + syn::Pat::Macro(_macro) => {} + syn::Pat::Path(_path) => {} + syn::Pat::Range(_range) => {} + syn::Pat::Rest(_rest) => {} + syn::Pat::Verbatim(_tokens) => {} + syn::Pat::Wild(_underscore) => {} + syn::Pat::Ident(ident) => { + ident.by_ref = None; + ident.mutability = None; + if let Some((_at, pat)) = &mut ident.subpat { + clean_pattern(&mut *pat); + } + } + syn::Pat::Or(or) => { + for case in or.cases.iter_mut() { + clean_pattern(case); + } + } + syn::Pat::Slice(slice) => { + for elem in slice.elems.iter_mut() { + clean_pattern(elem); + } + } + syn::Pat::Struct(struct_pat) => { + for field in struct_pat.fields.iter_mut() { + clean_pattern(&mut field.pat); + } + } + syn::Pat::Tuple(tuple) => { + for elem in tuple.elems.iter_mut() { + clean_pattern(elem); + } + } + syn::Pat::TupleStruct(tuple) => { + for elem in tuple.pat.elems.iter_mut() { + clean_pattern(elem); + } + } + syn::Pat::Reference(reference) => { + reference.mutability = None; + clean_pattern(&mut *reference.pat); + } + syn::Pat::Type(type_pat) => { + clean_pattern(&mut *type_pat.pat); + } + _ => {} + } +} |