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-rw-r--r--src/tools/rustfmt/config_proc_macro/Cargo.lock68
-rw-r--r--src/tools/rustfmt/config_proc_macro/Cargo.toml23
-rw-r--r--src/tools/rustfmt/config_proc_macro/src/attrs.rs57
-rw-r--r--src/tools/rustfmt/config_proc_macro/src/config_type.rs15
-rw-r--r--src/tools/rustfmt/config_proc_macro/src/item_enum.rs208
-rw-r--r--src/tools/rustfmt/config_proc_macro/src/item_struct.rs5
-rw-r--r--src/tools/rustfmt/config_proc_macro/src/lib.rs71
-rw-r--r--src/tools/rustfmt/config_proc_macro/src/utils.rs52
-rw-r--r--src/tools/rustfmt/config_proc_macro/tests/smoke.rs20
9 files changed, 519 insertions, 0 deletions
diff --git a/src/tools/rustfmt/config_proc_macro/Cargo.lock b/src/tools/rustfmt/config_proc_macro/Cargo.lock
new file mode 100644
index 000000000..ecf561f28
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/Cargo.lock
@@ -0,0 +1,68 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e98a83a9f9b331f54b924e68a66acb1bb35cb01fb0a23645139967abefb697e8"
+dependencies = [
+ "unicode-xid",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "rustfmt-config_proc_macro"
+version = "0.2.0"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "serde",
+ "syn",
+]
+
+[[package]]
+name = "serde"
+version = "1.0.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fec2851eb56d010dc9a21b89ca53ee75e6528bab60c11e89d38390904982da9f"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb4dc18c61206b08dc98216c98faa0232f4337e1e1b8574551d5bad29ea1b425"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66850e97125af79138385e9b88339cbcd037e3f28ceab8c5ad98e64f0f1f80bf"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
diff --git a/src/tools/rustfmt/config_proc_macro/Cargo.toml b/src/tools/rustfmt/config_proc_macro/Cargo.toml
new file mode 100644
index 000000000..a41b3a5e6
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/Cargo.toml
@@ -0,0 +1,23 @@
+[package]
+name = "rustfmt-config_proc_macro"
+version = "0.2.0"
+edition = "2018"
+description = "A collection of procedural macros for rustfmt"
+license = "Apache-2.0/MIT"
+categories = ["development-tools::procedural-macro-helpers"]
+repository = "https://github.com/rust-lang/rustfmt"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = { version = "1.0", features = ["full", "visit"] }
+
+[dev-dependencies]
+serde = { version = "1.0", features = ["derive"] }
+
+[features]
+default = []
+debug-with-rustfmt = []
diff --git a/src/tools/rustfmt/config_proc_macro/src/attrs.rs b/src/tools/rustfmt/config_proc_macro/src/attrs.rs
new file mode 100644
index 000000000..0baba046f
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/src/attrs.rs
@@ -0,0 +1,57 @@
+//! This module provides utilities for handling attributes on variants
+//! of `config_type` enum. Currently there are two types of attributes
+//! that could appear on the variants of `config_type` enum: `doc_hint`
+//! and `value`. Both comes in the form of name-value pair whose value
+//! is string literal.
+
+/// Returns the value of the first `doc_hint` attribute in the given slice or
+/// `None` if `doc_hint` attribute is not available.
+pub fn find_doc_hint(attrs: &[syn::Attribute]) -> Option<String> {
+ attrs.iter().filter_map(doc_hint).next()
+}
+
+/// Returns `true` if the given attribute is a `doc_hint` attribute.
+pub fn is_doc_hint(attr: &syn::Attribute) -> bool {
+ is_attr_name_value(attr, "doc_hint")
+}
+
+/// Returns a string literal value if the given attribute is `doc_hint`
+/// attribute or `None` otherwise.
+pub fn doc_hint(attr: &syn::Attribute) -> Option<String> {
+ get_name_value_str_lit(attr, "doc_hint")
+}
+
+/// Returns the value of the first `value` attribute in the given slice or
+/// `None` if `value` attribute is not available.
+pub fn find_config_value(attrs: &[syn::Attribute]) -> Option<String> {
+ attrs.iter().filter_map(config_value).next()
+}
+
+/// Returns a string literal value if the given attribute is `value`
+/// attribute or `None` otherwise.
+pub fn config_value(attr: &syn::Attribute) -> Option<String> {
+ get_name_value_str_lit(attr, "value")
+}
+
+/// Returns `true` if the given attribute is a `value` attribute.
+pub fn is_config_value(attr: &syn::Attribute) -> bool {
+ is_attr_name_value(attr, "value")
+}
+
+fn is_attr_name_value(attr: &syn::Attribute, name: &str) -> bool {
+ attr.parse_meta().ok().map_or(false, |meta| match meta {
+ syn::Meta::NameValue(syn::MetaNameValue { ref path, .. }) if path.is_ident(name) => true,
+ _ => false,
+ })
+}
+
+fn get_name_value_str_lit(attr: &syn::Attribute, name: &str) -> Option<String> {
+ attr.parse_meta().ok().and_then(|meta| match meta {
+ syn::Meta::NameValue(syn::MetaNameValue {
+ ref path,
+ lit: syn::Lit::Str(ref lit_str),
+ ..
+ }) if path.is_ident(name) => Some(lit_str.value()),
+ _ => None,
+ })
+}
diff --git a/src/tools/rustfmt/config_proc_macro/src/config_type.rs b/src/tools/rustfmt/config_proc_macro/src/config_type.rs
new file mode 100644
index 000000000..93a78b846
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/src/config_type.rs
@@ -0,0 +1,15 @@
+use proc_macro2::TokenStream;
+
+use crate::item_enum::define_config_type_on_enum;
+use crate::item_struct::define_config_type_on_struct;
+
+/// Defines `config_type` on enum or struct.
+// FIXME: Implement this on struct.
+pub fn define_config_type(input: &syn::Item) -> TokenStream {
+ match input {
+ syn::Item::Struct(st) => define_config_type_on_struct(st),
+ syn::Item::Enum(en) => define_config_type_on_enum(en),
+ _ => panic!("Expected enum or struct"),
+ }
+ .unwrap()
+}
diff --git a/src/tools/rustfmt/config_proc_macro/src/item_enum.rs b/src/tools/rustfmt/config_proc_macro/src/item_enum.rs
new file mode 100644
index 000000000..dcee77a85
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/src/item_enum.rs
@@ -0,0 +1,208 @@
+use proc_macro2::TokenStream;
+use quote::quote;
+
+use crate::attrs::*;
+use crate::utils::*;
+
+type Variants = syn::punctuated::Punctuated<syn::Variant, syn::Token![,]>;
+
+/// Defines and implements `config_type` enum.
+pub fn define_config_type_on_enum(em: &syn::ItemEnum) -> syn::Result<TokenStream> {
+ let syn::ItemEnum {
+ vis,
+ enum_token,
+ ident,
+ generics,
+ variants,
+ ..
+ } = em;
+
+ let mod_name_str = format!("__define_config_type_on_enum_{}", ident);
+ let mod_name = syn::Ident::new(&mod_name_str, ident.span());
+ let variants = fold_quote(variants.iter().map(process_variant), |meta| quote!(#meta,));
+
+ let impl_doc_hint = impl_doc_hint(&em.ident, &em.variants);
+ let impl_from_str = impl_from_str(&em.ident, &em.variants);
+ let impl_display = impl_display(&em.ident, &em.variants);
+ let impl_serde = impl_serde(&em.ident, &em.variants);
+ let impl_deserialize = impl_deserialize(&em.ident, &em.variants);
+
+ Ok(quote! {
+ #[allow(non_snake_case)]
+ mod #mod_name {
+ #[derive(Debug, Copy, Clone, Eq, PartialEq)]
+ pub #enum_token #ident #generics { #variants }
+ #impl_display
+ #impl_doc_hint
+ #impl_from_str
+ #impl_serde
+ #impl_deserialize
+ }
+ #vis use #mod_name::#ident;
+ })
+}
+
+/// Remove attributes specific to `config_proc_macro` from enum variant fields.
+fn process_variant(variant: &syn::Variant) -> TokenStream {
+ let metas = variant
+ .attrs
+ .iter()
+ .filter(|attr| !is_doc_hint(attr) && !is_config_value(attr));
+ let attrs = fold_quote(metas, |meta| quote!(#meta));
+ let syn::Variant { ident, fields, .. } = variant;
+ quote!(#attrs #ident #fields)
+}
+
+fn impl_doc_hint(ident: &syn::Ident, variants: &Variants) -> TokenStream {
+ let doc_hint = variants
+ .iter()
+ .map(doc_hint_of_variant)
+ .collect::<Vec<_>>()
+ .join("|");
+ let doc_hint = format!("[{}]", doc_hint);
+ quote! {
+ use crate::config::ConfigType;
+ impl ConfigType for #ident {
+ fn doc_hint() -> String {
+ #doc_hint.to_owned()
+ }
+ }
+ }
+}
+
+fn impl_display(ident: &syn::Ident, variants: &Variants) -> TokenStream {
+ let vs = variants
+ .iter()
+ .filter(|v| is_unit(v))
+ .map(|v| (config_value_of_variant(v), &v.ident));
+ let match_patterns = fold_quote(vs, |(s, v)| {
+ quote! {
+ #ident::#v => write!(f, "{}", #s),
+ }
+ });
+ quote! {
+ use std::fmt;
+ impl fmt::Display for #ident {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ #match_patterns
+ _ => unimplemented!(),
+ }
+ }
+ }
+ }
+}
+
+fn impl_from_str(ident: &syn::Ident, variants: &Variants) -> TokenStream {
+ let vs = variants
+ .iter()
+ .filter(|v| is_unit(v))
+ .map(|v| (config_value_of_variant(v), &v.ident));
+ let if_patterns = fold_quote(vs, |(s, v)| {
+ quote! {
+ if #s.eq_ignore_ascii_case(s) {
+ return Ok(#ident::#v);
+ }
+ }
+ });
+ let mut err_msg = String::from("Bad variant, expected one of:");
+ for v in variants.iter().filter(|v| is_unit(v)) {
+ err_msg.push_str(&format!(" `{}`", v.ident));
+ }
+
+ quote! {
+ impl ::std::str::FromStr for #ident {
+ type Err = &'static str;
+
+ fn from_str(s: &str) -> Result<Self, Self::Err> {
+ #if_patterns
+ return Err(#err_msg);
+ }
+ }
+ }
+}
+
+fn doc_hint_of_variant(variant: &syn::Variant) -> String {
+ find_doc_hint(&variant.attrs).unwrap_or(variant.ident.to_string())
+}
+
+fn config_value_of_variant(variant: &syn::Variant) -> String {
+ find_config_value(&variant.attrs).unwrap_or(variant.ident.to_string())
+}
+
+fn impl_serde(ident: &syn::Ident, variants: &Variants) -> TokenStream {
+ let arms = fold_quote(variants.iter(), |v| {
+ let v_ident = &v.ident;
+ let pattern = match v.fields {
+ syn::Fields::Named(..) => quote!(#ident::v_ident{..}),
+ syn::Fields::Unnamed(..) => quote!(#ident::#v_ident(..)),
+ syn::Fields::Unit => quote!(#ident::#v_ident),
+ };
+ let option_value = config_value_of_variant(v);
+ quote! {
+ #pattern => serializer.serialize_str(&#option_value),
+ }
+ });
+
+ quote! {
+ impl ::serde::ser::Serialize for #ident {
+ fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+ where
+ S: ::serde::ser::Serializer,
+ {
+ use serde::ser::Error;
+ match self {
+ #arms
+ _ => Err(S::Error::custom(format!("Cannot serialize {:?}", self))),
+ }
+ }
+ }
+ }
+}
+
+// Currently only unit variants are supported.
+fn impl_deserialize(ident: &syn::Ident, variants: &Variants) -> TokenStream {
+ let supported_vs = variants.iter().filter(|v| is_unit(v));
+ let if_patterns = fold_quote(supported_vs, |v| {
+ let config_value = config_value_of_variant(v);
+ let variant_ident = &v.ident;
+ quote! {
+ if #config_value.eq_ignore_ascii_case(s) {
+ return Ok(#ident::#variant_ident);
+ }
+ }
+ });
+
+ let supported_vs = variants.iter().filter(|v| is_unit(v));
+ let allowed = fold_quote(supported_vs.map(config_value_of_variant), |s| quote!(#s,));
+
+ quote! {
+ impl<'de> serde::de::Deserialize<'de> for #ident {
+ fn deserialize<D>(d: D) -> Result<Self, D::Error>
+ where
+ D: serde::Deserializer<'de>,
+ {
+ use serde::de::{Error, Visitor};
+ use std::marker::PhantomData;
+ use std::fmt;
+ struct StringOnly<T>(PhantomData<T>);
+ impl<'de, T> Visitor<'de> for StringOnly<T>
+ where T: serde::Deserializer<'de> {
+ type Value = String;
+ fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ formatter.write_str("string")
+ }
+ fn visit_str<E>(self, value: &str) -> Result<String, E> {
+ Ok(String::from(value))
+ }
+ }
+ let s = &d.deserialize_string(StringOnly::<D>(PhantomData))?;
+
+ #if_patterns
+
+ static ALLOWED: &'static[&str] = &[#allowed];
+ Err(D::Error::unknown_variant(&s, ALLOWED))
+ }
+ }
+ }
+}
diff --git a/src/tools/rustfmt/config_proc_macro/src/item_struct.rs b/src/tools/rustfmt/config_proc_macro/src/item_struct.rs
new file mode 100644
index 000000000..f03ff7e30
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/src/item_struct.rs
@@ -0,0 +1,5 @@
+use proc_macro2::TokenStream;
+
+pub fn define_config_type_on_struct(_st: &syn::ItemStruct) -> syn::Result<TokenStream> {
+ unimplemented!()
+}
diff --git a/src/tools/rustfmt/config_proc_macro/src/lib.rs b/src/tools/rustfmt/config_proc_macro/src/lib.rs
new file mode 100644
index 000000000..e772c53f4
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/src/lib.rs
@@ -0,0 +1,71 @@
+//! This crate provides a derive macro for `ConfigType`.
+
+#![recursion_limit = "256"]
+
+mod attrs;
+mod config_type;
+mod item_enum;
+mod item_struct;
+mod utils;
+
+use std::str::FromStr;
+
+use proc_macro::TokenStream;
+use syn::parse_macro_input;
+
+#[proc_macro_attribute]
+pub fn config_type(_args: TokenStream, input: TokenStream) -> TokenStream {
+ let input = parse_macro_input!(input as syn::Item);
+ let output = config_type::define_config_type(&input);
+
+ #[cfg(feature = "debug-with-rustfmt")]
+ {
+ utils::debug_with_rustfmt(&output);
+ }
+
+ TokenStream::from(output)
+}
+
+/// Used to conditionally output the TokenStream for tests that need to be run on nightly only.
+///
+/// ```rust
+/// # use rustfmt_config_proc_macro::nightly_only_test;
+///
+/// #[nightly_only_test]
+/// #[test]
+/// fn test_needs_nightly_rustfmt() {
+/// assert!(true);
+/// }
+/// ```
+#[proc_macro_attribute]
+pub fn nightly_only_test(_args: TokenStream, input: TokenStream) -> TokenStream {
+ // if CFG_RELEASE_CHANNEL is not set we default to nightly, hence why the default is true
+ if option_env!("CFG_RELEASE_CHANNEL").map_or(true, |c| c == "nightly" || c == "dev") {
+ input
+ } else {
+ // output an empty token stream if CFG_RELEASE_CHANNEL is not set to "nightly" or "dev"
+ TokenStream::from_str("").unwrap()
+ }
+}
+
+/// Used to conditionally output the TokenStream for tests that need to be run on stable only.
+///
+/// ```rust
+/// # use rustfmt_config_proc_macro::stable_only_test;
+///
+/// #[stable_only_test]
+/// #[test]
+/// fn test_needs_stable_rustfmt() {
+/// assert!(true);
+/// }
+/// ```
+#[proc_macro_attribute]
+pub fn stable_only_test(_args: TokenStream, input: TokenStream) -> TokenStream {
+ // if CFG_RELEASE_CHANNEL is not set we default to nightly, hence why the default is false
+ if option_env!("CFG_RELEASE_CHANNEL").map_or(false, |c| c == "stable") {
+ input
+ } else {
+ // output an empty token stream if CFG_RELEASE_CHANNEL is not set or is not 'stable'
+ TokenStream::from_str("").unwrap()
+ }
+}
diff --git a/src/tools/rustfmt/config_proc_macro/src/utils.rs b/src/tools/rustfmt/config_proc_macro/src/utils.rs
new file mode 100644
index 000000000..f5cba87b0
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/src/utils.rs
@@ -0,0 +1,52 @@
+use proc_macro2::TokenStream;
+use quote::{quote, ToTokens};
+
+pub fn fold_quote<F, I, T>(input: impl Iterator<Item = I>, f: F) -> TokenStream
+where
+ F: Fn(I) -> T,
+ T: ToTokens,
+{
+ input.fold(quote! {}, |acc, x| {
+ let y = f(x);
+ quote! { #acc #y }
+ })
+}
+
+pub fn is_unit(v: &syn::Variant) -> bool {
+ match v.fields {
+ syn::Fields::Unit => true,
+ _ => false,
+ }
+}
+
+#[cfg(feature = "debug-with-rustfmt")]
+/// Pretty-print the output of proc macro using rustfmt.
+pub fn debug_with_rustfmt(input: &TokenStream) {
+ use std::env;
+ use std::ffi::OsStr;
+ use std::io::Write;
+ use std::process::{Command, Stdio};
+
+ let rustfmt_var = env::var_os("RUSTFMT");
+ let rustfmt = match &rustfmt_var {
+ Some(rustfmt) => rustfmt,
+ None => OsStr::new("rustfmt"),
+ };
+ let mut child = Command::new(rustfmt)
+ .stdin(Stdio::piped())
+ .stdout(Stdio::piped())
+ .spawn()
+ .expect("Failed to spawn rustfmt in stdio mode");
+ {
+ let stdin = child.stdin.as_mut().expect("Failed to get stdin");
+ stdin
+ .write_all(format!("{}", input).as_bytes())
+ .expect("Failed to write to stdin");
+ }
+ let rustfmt_output = child.wait_with_output().expect("rustfmt has failed");
+
+ eprintln!(
+ "{}",
+ String::from_utf8(rustfmt_output.stdout).expect("rustfmt returned non-UTF8 string")
+ );
+}
diff --git a/src/tools/rustfmt/config_proc_macro/tests/smoke.rs b/src/tools/rustfmt/config_proc_macro/tests/smoke.rs
new file mode 100644
index 000000000..940a8a0c2
--- /dev/null
+++ b/src/tools/rustfmt/config_proc_macro/tests/smoke.rs
@@ -0,0 +1,20 @@
+pub mod config {
+ pub trait ConfigType: Sized {
+ fn doc_hint() -> String;
+ }
+}
+
+#[allow(dead_code)]
+#[allow(unused_imports)]
+mod tests {
+ use rustfmt_config_proc_macro::config_type;
+
+ #[config_type]
+ enum Bar {
+ Foo,
+ Bar,
+ #[doc_hint = "foo_bar"]
+ FooBar,
+ FooFoo(i32),
+ }
+}