proc-macro-hack-0.5.9/.gitignore010064400017500001750000000000221346021527100146770ustar0000000000000000target Cargo.lock proc-macro-hack-0.5.9/.travis.yml010066400017500001750000000006001352457145400150350ustar0000000000000000sudo: false language: rust rust: - nightly - beta - stable - 1.31.0 script: - cargo run --manifest-path example/Cargo.toml matrix: include: - rust: nightly name: Minimal versions before_script: - cargo update -Z minimal-versions --manifest-path example/Cargo.toml - rust: 1.31.0 name: 2015 edition script: - cargo check proc-macro-hack-0.5.9/Cargo.toml.orig010066400017500001750000000012651352457153400156220ustar0000000000000000[package] name = "proc-macro-hack" version = "0.5.9" authors = ["David Tolnay "] license = "MIT OR Apache-2.0" description = "Procedural macros in expression position" repository = "https://github.com/dtolnay/proc-macro-hack" categories = ["development-tools::procedural-macro-helpers"] readme = "README.md" [lib] proc-macro = true [dependencies] proc-macro2 = "1.0" quote = "1.0" syn = "1.0" [dev-dependencies] demo-hack = { version = "0.0.5", path = "demo-hack" } demo-hack-impl = { version = "0.0.5", path = "demo-hack-impl" } [badges] travis-ci = { repository = "dtolnay/proc-macro-hack" } [workspace] members = ["demo-hack", "demo-hack-impl", "example", "nested"] proc-macro-hack-0.5.9/Cargo.toml0000644000000022000000000000000120440ustar00# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO # # When uploading crates to the registry Cargo will automatically # "normalize" Cargo.toml files for maximal compatibility # with all versions of Cargo and also rewrite `path` dependencies # to registry (e.g., crates.io) dependencies # # If you believe there's an error in this file please file an # issue against the rust-lang/cargo repository. If you're # editing this file be aware that the upstream Cargo.toml # will likely look very different (and much more reasonable) [package] name = "proc-macro-hack" version = "0.5.9" authors = ["David Tolnay "] description = "Procedural macros in expression position" readme = "README.md" categories = ["development-tools::procedural-macro-helpers"] license = "MIT OR Apache-2.0" repository = "https://github.com/dtolnay/proc-macro-hack" [lib] proc-macro = true [dependencies.proc-macro2] version = "1.0" [dependencies.quote] version = "1.0" [dependencies.syn] version = "1.0" [dev-dependencies.demo-hack] version = "0.0.5" [dev-dependencies.demo-hack-impl] version = "0.0.5" [badges.travis-ci] repository = "dtolnay/proc-macro-hack" proc-macro-hack-0.5.9/LICENSE-APACHE010064400017500001750000000251371346021527100146510ustar0000000000000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. 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See the License for the specific language governing permissions and limitations under the License. proc-macro-hack-0.5.9/LICENSE-MIT010064400017500001750000000020401346021527100143450ustar0000000000000000Copyright (c) 2018 David Tolnay Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. proc-macro-hack-0.5.9/README.md010066400017500001750000000106001352457145400142040ustar0000000000000000Procedural macros in expression position ======================================== [![Build Status](https://api.travis-ci.org/dtolnay/proc-macro-hack.svg?branch=master)](https://travis-ci.org/dtolnay/proc-macro-hack) [![Latest Version](https://img.shields.io/crates/v/proc-macro-hack.svg)](https://crates.io/crates/proc-macro-hack) As of Rust 1.30, the language supports user-defined function-like procedural macros. However these can only be invoked in item position, not in statements or expressions. This crate implements an alternative type of procedural macro that can be invoked in statement or expression position. This approach works with any stable or nightly Rust version 1.30+. ## Defining procedural macros Two crates are required to define a procedural macro. ### The implementation crate This crate must contain nothing but procedural macros. Private helper functions and private modules are fine but nothing can be public. [> example of an implementation crate][demo-hack-impl] Just like you would use a #\[proc_macro\] attribute to define a natively supported procedural macro, use proc-macro-hack's #\[proc_macro_hack\] attribute to define a procedural macro that works in expression position. The function signature is the same as for ordinary function-like procedural macros. ```rust extern crate proc_macro; use proc_macro::TokenStream; use proc_macro_hack::proc_macro_hack; use quote::quote; use syn::{parse_macro_input, Expr}; #[proc_macro_hack] pub fn add_one(input: TokenStream) -> TokenStream { let expr = parse_macro_input!(input as Expr); TokenStream::from(quote! { 1 + (#expr) }) } ``` ### The declaration crate This crate is allowed to contain other public things if you need, for example traits or functions or ordinary macros. [> example of a declaration crate][demo-hack] Within the declaration crate there needs to be a re-export of your procedural macro from the implementation crate. The re-export also carries a \#\[proc_macro_hack\] attribute. ```rust use proc_macro_hack::proc_macro_hack; /// Add one to an expression. /// /// (Documentation goes here on the re-export, not in the other crate.) #[proc_macro_hack] pub use demo_hack_impl::add_one; ``` Both crates depend on `proc-macro-hack`: ```toml [dependencies] proc-macro-hack = "0.5" ``` Additionally, your implementation crate (but not your declaration crate) is a proc macro crate: ```toml [lib] proc-macro = true ``` ## Using procedural macros Users of your crate depend on your declaration crate (not your implementation crate), then use your procedural macros as usual. [> example of a downstream crate][example] ```rust use demo_hack::add_one; fn main() { let two = 2; let nine = add_one!(two) + add_one!(2 + 3); println!("nine = {}", nine); } ``` [demo-hack-impl]: https://github.com/dtolnay/proc-macro-hack/tree/master/demo-hack-impl [demo-hack]: https://github.com/dtolnay/proc-macro-hack/tree/master/demo-hack [example]: https://github.com/dtolnay/proc-macro-hack/tree/master/example ## Limitations - Only proc macros in expression position are supported. Proc macros in type position ([#10]) or pattern position ([#20]) are not supported. - By default, nested invocations are not supported i.e. the code emitted by a proc-macro-hack macro invocation cannot contain recursive calls to the same proc-macro-hack macro nor calls to any other proc-macro-hack macros. Use [`proc-macro-nested`] if you require support for nested invocations. - By default, hygiene is structured such that the expanded code can't refer to local variables other than those passed by name somewhere in the macro input. If your macro must refer to *local* variables that don't get named in the macro input, use `#[proc_macro_hack(fake_call_site)]` on the re-export in your declaration crate. *Most macros won't need this.* [#10]: https://github.com/dtolnay/proc-macro-hack/issues/10 [#20]: https://github.com/dtolnay/proc-macro-hack/issues/20 [`proc-macro-nested`]: https://docs.rs/proc-macro-nested
#### License Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this hack by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. proc-macro-hack-0.5.9/src/lib.rs010066400017500001750000000454401352457145400146420ustar0000000000000000//! As of Rust 1.30, the language supports user-defined function-like procedural //! macros. However these can only be invoked in item position, not in //! statements or expressions. //! //! This crate implements an alternative type of procedural macro that can be //! invoked in statement or expression position. //! //! # Defining procedural macros //! //! Two crates are required to define a procedural macro. //! //! ## The implementation crate //! //! This crate must contain nothing but procedural macros. Private helper //! functions and private modules are fine but nothing can be public. //! //! [> example of an implementation crate][demo-hack-impl] //! //! Just like you would use a #\[proc_macro\] attribute to define a natively //! supported procedural macro, use proc-macro-hack's #\[proc_macro_hack\] //! attribute to define a procedural macro that works in expression position. //! The function signature is the same as for ordinary function-like procedural //! macros. //! //! ``` //! extern crate proc_macro; //! //! use proc_macro::TokenStream; //! use proc_macro_hack::proc_macro_hack; //! use quote::quote; //! use syn::{parse_macro_input, Expr}; //! //! # const IGNORE: &str = stringify! { //! #[proc_macro_hack] //! # }; //! pub fn add_one(input: TokenStream) -> TokenStream { //! let expr = parse_macro_input!(input as Expr); //! TokenStream::from(quote! { //! 1 + (#expr) //! }) //! } //! # //! # fn main() {} //! ``` //! //! ## The declaration crate //! //! This crate is allowed to contain other public things if you need, for //! example traits or functions or ordinary macros. //! //! [> example of a declaration crate][demo-hack] //! //! Within the declaration crate there needs to be a re-export of your //! procedural macro from the implementation crate. The re-export also carries a //! \#\[proc_macro_hack\] attribute. //! //! ``` //! use proc_macro_hack::proc_macro_hack; //! //! /// Add one to an expression. //! /// //! /// (Documentation goes here on the re-export, not in the other crate.) //! #[proc_macro_hack] //! pub use demo_hack_impl::add_one; //! # //! # fn main() {} //! ``` //! //! Both crates depend on `proc-macro-hack`: //! //! ```toml //! [dependencies] //! proc-macro-hack = "0.5" //! ``` //! //! Additionally, your implementation crate (but not your declaration crate) is //! a proc macro crate: //! //! ```toml //! [lib] //! proc-macro = true //! ``` //! //! # Using procedural macros //! //! Users of your crate depend on your declaration crate (not your //! implementation crate), then use your procedural macros as usual. //! //! [> example of a downstream crate][example] //! //! ``` //! use demo_hack::add_one; //! //! fn main() { //! let two = 2; //! let nine = add_one!(two) + add_one!(2 + 3); //! println!("nine = {}", nine); //! } //! ``` //! //! [demo-hack-impl]: https://github.com/dtolnay/proc-macro-hack/tree/master/demo-hack-impl //! [demo-hack]: https://github.com/dtolnay/proc-macro-hack/tree/master/demo-hack //! [example]: https://github.com/dtolnay/proc-macro-hack/tree/master/example //! //! # Limitations //! //! - Only proc macros in expression position are supported. Proc macros in type //! position ([#10]) or pattern position ([#20]) are not supported. //! //! - By default, nested invocations are not supported i.e. the code emitted by //! a proc-macro-hack macro invocation cannot contain recursive calls to the //! same proc-macro-hack macro nor calls to any other proc-macro-hack macros. //! Use [`proc-macro-nested`] if you require support for nested invocations. //! //! - By default, hygiene is structured such that the expanded code can't refer //! to local variables other than those passed by name somewhere in the macro //! input. If your macro must refer to *local* variables that don't get named //! in the macro input, use `#[proc_macro_hack(fake_call_site)]` on the //! re-export in your declaration crate. *Most macros won't need this.* //! //! [#10]: https://github.com/dtolnay/proc-macro-hack/issues/10 //! [#20]: https://github.com/dtolnay/proc-macro-hack/issues/20 //! [`proc-macro-nested`]: https://docs.rs/proc-macro-nested #![recursion_limit = "512"] #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))] #![cfg_attr(feature = "cargo-clippy", allow(needless_pass_by_value))] extern crate proc_macro; extern crate proc_macro2; extern crate quote; extern crate syn; use std::fmt::Write; use proc_macro2::{Span, TokenStream, TokenTree}; use quote::{format_ident, quote, ToTokens}; use syn::parse::{Parse, ParseStream, Result}; use syn::{braced, bracketed, parenthesized, parse_macro_input, token, Ident, Token}; type Visibility = Option; enum Input { Export(Export), Define(Define), } // pub use demo_hack_impl::{m1, m2 as qrst}; struct Export { attrs: TokenStream, vis: Visibility, from: Ident, macros: Vec, } // pub fn m1(input: TokenStream) -> TokenStream { ... } struct Define { attrs: TokenStream, name: Ident, body: TokenStream, } struct Macro { name: Ident, export_as: Ident, } impl Parse for Input { fn parse(input: ParseStream) -> Result { let ahead = input.fork(); parse_attributes(&ahead)?; ahead.parse::()?; if ahead.peek(Token![use]) { input.parse().map(Input::Export) } else if ahead.peek(Token![fn]) { input.parse().map(Input::Define) } else { Err(input.error("unexpected input to #[proc_macro_hack]")) } } } impl Parse for Export { fn parse(input: ParseStream) -> Result { let attrs = input.call(parse_attributes)?; let vis: Visibility = input.parse()?; input.parse::()?; input.parse::>()?; let from: Ident = input.parse()?; input.parse::()?; let mut macros = Vec::new(); if input.peek(token::Brace) { let content; braced!(content in input); loop { macros.push(content.parse()?); if content.is_empty() { break; } content.parse::()?; if content.is_empty() { break; } } } else { macros.push(input.parse()?); } input.parse::()?; Ok(Export { attrs, vis, from, macros }) } } impl Parse for Define { fn parse(input: ParseStream) -> Result { let attrs = input.call(parse_attributes)?; let vis: Visibility = input.parse()?; if vis.is_none() { return Err(input.error("functions tagged with `#[proc_macro_hack]` must be `pub`")); } input.parse::()?; let name: Ident = input.parse()?; let body: TokenStream = input.parse()?; Ok(Define { attrs, name, body }) } } impl Parse for Macro { fn parse(input: ParseStream) -> Result { let name: Ident = input.parse()?; let renamed: Option = input.parse()?; let export_as = if renamed.is_some() { input.parse()? } else { name.clone() }; Ok(Macro { name, export_as }) } } fn parse_attributes(input: ParseStream) -> Result { let mut attrs = TokenStream::new(); while input.peek(Token![#]) { let pound: Token![#] = input.parse()?; pound.to_tokens(&mut attrs); let content; let bracket_token = bracketed!(content in input); let content: TokenStream = content.parse()?; bracket_token.surround(&mut attrs, |tokens| content.to_tokens(tokens)); } Ok(attrs) } #[proc_macro_attribute] pub fn proc_macro_hack( args: proc_macro::TokenStream, input: proc_macro::TokenStream, ) -> proc_macro::TokenStream { proc_macro::TokenStream::from(match parse_macro_input!(input) { Input::Export(export) => { let args = parse_macro_input!(args as ExportArgs); expand_export(export, args) } Input::Define(define) => { parse_macro_input!(args as DefineArgs); expand_define(define) } }) } mod kw { syn::custom_keyword!(derive); syn::custom_keyword!(fake_call_site); syn::custom_keyword!(support_nested); } struct ExportArgs { support_nested: bool, fake_call_site: bool, } impl Parse for ExportArgs { fn parse(input: ParseStream) -> Result { let mut args = ExportArgs { support_nested: false, fake_call_site: false, }; while !input.is_empty() { let ahead = input.lookahead1(); if ahead.peek(kw::support_nested) { input.parse::()?; args.support_nested = true; } else if ahead.peek(kw::fake_call_site) { input.parse::()?; args.fake_call_site = true; } else { return Err(ahead.error()); } if input.is_empty() { break; } input.parse::()?; } Ok(args) } } struct DefineArgs; impl Parse for DefineArgs { fn parse(_input: ParseStream) -> Result { Ok(DefineArgs) } } struct EnumHack { token_stream: TokenStream, } impl Parse for EnumHack { fn parse(input: ParseStream) -> Result { input.parse::()?; input.parse::()?; let braces; braced!(braces in input); braces.parse::()?; braces.parse::()?; let parens; parenthesized!(parens in braces); parens.parse::()?; parens.parse::()?; let inner; braced!(inner in parens); let token_stream: TokenStream = inner.parse()?; parens.parse::()?; parens.parse::()?; braces.parse::()?; braces.parse::()?; braces.parse::()?; Ok(EnumHack { token_stream }) } } #[doc(hidden)] #[proc_macro_derive(ProcMacroHack)] pub fn enum_hack(input: proc_macro::TokenStream) -> proc_macro::TokenStream { let inner = parse_macro_input!(input as EnumHack); proc_macro::TokenStream::from(inner.token_stream) } struct FakeCallSite { derive: Ident, rest: TokenStream, } impl Parse for FakeCallSite { fn parse(input: ParseStream) -> Result { input.parse::()?; let attr; bracketed!(attr in input); attr.parse::()?; let path; parenthesized!(path in attr); Ok(FakeCallSite { derive: path.parse()?, rest: input.parse()?, }) } } #[doc(hidden)] #[proc_macro_attribute] pub fn fake_call_site( args: proc_macro::TokenStream, input: proc_macro::TokenStream, ) -> proc_macro::TokenStream { let args = TokenStream::from(args); let span = match args.into_iter().next() { Some(token) => token.span(), None => return input, }; let input = parse_macro_input!(input as FakeCallSite); let mut derive = input.derive; derive.set_span(span); let rest = input.rest; let expanded = quote! { #[derive(#derive)] #rest }; proc_macro::TokenStream::from(expanded) } fn expand_export(export: Export, args: ExportArgs) -> TokenStream { let dummy = dummy_name_for_export(&export); let attrs = export.attrs; let vis = export.vis; let macro_export = match vis { Some(_) => quote!(#[macro_export]), None => quote!(), }; let crate_prefix = vis.map(|_| quote!($crate::)); let enum_variant = if args.support_nested { quote!(Nested) } else { quote!(Value) }; let from = export.from; let rules = export .macros .into_iter() .map(|Macro { name, export_as }| { let actual_name = actual_proc_macro_name(&name); let dispatch = dispatch_macro_name(&name); let call_site = call_site_macro_name(&name); let export_dispatch = if args.support_nested { quote! { #[doc(hidden)] #vis use proc_macro_nested::dispatch as #dispatch; } } else { quote!() }; let proc_macro_call = if args.support_nested { quote! { #crate_prefix #dispatch! { ($($proc_macro)*) } } } else { quote! { proc_macro_call!() } }; let export_call_site = if args.fake_call_site { quote! { #[doc(hidden)] #vis use proc_macro_hack::fake_call_site as #call_site; } } else { quote!() }; let do_derive = if !args.fake_call_site { quote! { #[derive(#crate_prefix #actual_name)] } } else if crate_prefix.is_some() { quote! { use #crate_prefix #actual_name; #[#crate_prefix #call_site ($($proc_macro)*)] #[derive(#actual_name)] } } else { quote! { #[#call_site ($($proc_macro)*)] #[derive(#actual_name)] } }; quote! { #[doc(hidden)] #vis use #from::#actual_name; #export_dispatch #export_call_site #attrs #macro_export macro_rules! #export_as { ($($proc_macro:tt)*) => {{ #do_derive enum ProcMacroHack { #enum_variant = (stringify! { $($proc_macro)* }, 0).1, } #proc_macro_call }}; } } }) .collect(); wrap_in_enum_hack(dummy, rules) } fn expand_define(define: Define) -> TokenStream { let attrs = define.attrs; let name = define.name; let dummy = actual_proc_macro_name(&name); let body = define.body; quote! { mod #dummy { extern crate proc_macro; pub use self::proc_macro::*; } #attrs #[proc_macro_derive(#dummy)] pub fn #dummy(input: #dummy::TokenStream) -> #dummy::TokenStream { use std::iter::FromIterator; let mut iter = input.into_iter(); iter.next().unwrap(); // `enum` iter.next().unwrap(); // `ProcMacroHack` let mut braces = match iter.next().unwrap() { #dummy::TokenTree::Group(group) => group.stream().into_iter(), _ => unimplemented!(), }; let variant = braces.next().unwrap(); // `Value` or `Nested` let support_nested = variant.to_string() == "Nested"; braces.next().unwrap(); // `=` let mut parens = match braces.next().unwrap() { #dummy::TokenTree::Group(group) => group.stream().into_iter(), _ => unimplemented!(), }; parens.next().unwrap(); // `stringify` parens.next().unwrap(); // `!` let inner = match parens.next().unwrap() { #dummy::TokenTree::Group(group) => group.stream(), _ => unimplemented!(), }; let output: #dummy::TokenStream = #name(inner.clone()); fn count_bangs(input: #dummy::TokenStream) -> usize { let mut count = 0; for token in input { match token { #dummy::TokenTree::Punct(punct) => { if punct.as_char() == '!' { count += 1; } } #dummy::TokenTree::Group(group) => { count += count_bangs(group.stream()); } _ => {} } } count } // macro_rules! proc_macro_call { // () => { #output } // } #dummy::TokenStream::from_iter(vec![ #dummy::TokenTree::Ident( #dummy::Ident::new("macro_rules", #dummy::Span::call_site()), ), #dummy::TokenTree::Punct( #dummy::Punct::new('!', #dummy::Spacing::Alone), ), #dummy::TokenTree::Ident( #dummy::Ident::new( &if support_nested { format!("proc_macro_call_{}", count_bangs(inner)) } else { String::from("proc_macro_call") }, #dummy::Span::call_site(), ), ), #dummy::TokenTree::Group( #dummy::Group::new(#dummy::Delimiter::Brace, #dummy::TokenStream::from_iter(vec![ #dummy::TokenTree::Group( #dummy::Group::new(#dummy::Delimiter::Parenthesis, #dummy::TokenStream::new()), ), #dummy::TokenTree::Punct( #dummy::Punct::new('=', #dummy::Spacing::Joint), ), #dummy::TokenTree::Punct( #dummy::Punct::new('>', #dummy::Spacing::Alone), ), #dummy::TokenTree::Group( #dummy::Group::new(#dummy::Delimiter::Brace, output), ), ])), ), ]) } fn #name #body } } fn actual_proc_macro_name(conceptual: &Ident) -> Ident { format_ident!("proc_macro_hack_{}", conceptual) } fn dispatch_macro_name(conceptual: &Ident) -> Ident { format_ident!("proc_macro_call_{}", conceptual) } fn call_site_macro_name(conceptual: &Ident) -> Ident { format_ident!("proc_macro_fake_call_site_{}", conceptual) } fn dummy_name_for_export(export: &Export) -> String { let mut dummy = String::new(); write!(dummy, "_{}{}", export.from.to_string().len(), export.from).unwrap(); for m in &export.macros { write!(dummy, "_{}{}", m.name.to_string().len(), m.name).unwrap(); } dummy } fn wrap_in_enum_hack(dummy: String, inner: TokenStream) -> TokenStream { let dummy = Ident::new(&dummy, Span::call_site()); quote! { #[derive(proc_macro_hack::ProcMacroHack)] enum #dummy { Value = (stringify! { #inner }, 0).1, } } } proc-macro-hack-0.5.9/.cargo_vcs_info.json0000644000000001120000000000000140460ustar00{ "git": { "sha1": "075d330930f19c42ad35249c5986d4f94d178228" } }