mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-21 22:34:05 +00:00
Convert newtype_index
to a proc macro
The `macro_rules!` implementation was becomng excessively complicated, and difficult to modify. The new proc macro implementation should make it much easier to add new features (e.g. skipping certain `#[derive]`s)
This commit is contained in:
parent
4b043faba3
commit
339bbebbc1
@ -12,6 +12,8 @@ pub mod bit_set;
|
||||
pub mod interval;
|
||||
pub mod vec;
|
||||
|
||||
pub use rustc_macros::newtype_index;
|
||||
|
||||
/// Type size assertion. The first argument is a type and the second argument is its expected size.
|
||||
#[macro_export]
|
||||
macro_rules! static_assert_size {
|
||||
|
@ -49,461 +49,6 @@ impl Idx for u32 {
|
||||
}
|
||||
}
|
||||
|
||||
/// Creates a struct type `S` that can be used as an index with
|
||||
/// `IndexVec` and so on.
|
||||
///
|
||||
/// There are two ways of interacting with these indices:
|
||||
///
|
||||
/// - The `From` impls are the preferred way. So you can do
|
||||
/// `S::from(v)` with a `usize` or `u32`. And you can convert back
|
||||
/// to an integer with `u32::from(s)`.
|
||||
///
|
||||
/// - Alternatively, you can use the methods `S::new(v)` and `s.index()`
|
||||
/// to create/return a value.
|
||||
///
|
||||
/// Internally, the index uses a u32, so the index must not exceed
|
||||
/// `u32::MAX`. You can also customize things like the `Debug` impl,
|
||||
/// what traits are derived, and so forth via the macro.
|
||||
#[macro_export]
|
||||
#[allow_internal_unstable(step_trait, rustc_attrs, trusted_step)]
|
||||
macro_rules! newtype_index {
|
||||
// ---- public rules ----
|
||||
|
||||
// Use default constants
|
||||
($(#[$attrs:meta])* $v:vis struct $name:ident { .. }) => (
|
||||
$crate::newtype_index!(
|
||||
// Leave out derives marker so we can use its absence to ensure it comes first
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$name]
|
||||
// shave off 256 indices at the end to allow space for packing these indices into enums
|
||||
@max [0xFFFF_FF00]
|
||||
@vis [$v]
|
||||
@debug_format ["{}"]);
|
||||
);
|
||||
|
||||
// Define any constants
|
||||
($(#[$attrs:meta])* $v:vis struct $name:ident { $($tokens:tt)+ }) => (
|
||||
$crate::newtype_index!(
|
||||
// Leave out derives marker so we can use its absence to ensure it comes first
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$name]
|
||||
// shave off 256 indices at the end to allow space for packing these indices into enums
|
||||
@max [0xFFFF_FF00]
|
||||
@vis [$v]
|
||||
@debug_format ["{}"]
|
||||
$($tokens)+);
|
||||
);
|
||||
|
||||
// ---- private rules ----
|
||||
|
||||
// Base case, user-defined constants (if any) have already been defined
|
||||
(@derives [$($derives:ident,)*]
|
||||
@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]) => (
|
||||
$(#[$attrs])*
|
||||
#[derive(Copy, PartialEq, Eq, Hash, PartialOrd, Ord, $($derives),*)]
|
||||
#[rustc_layout_scalar_valid_range_end($max)]
|
||||
$v struct $type {
|
||||
private: u32
|
||||
}
|
||||
|
||||
impl Clone for $type {
|
||||
#[inline]
|
||||
fn clone(&self) -> Self {
|
||||
*self
|
||||
}
|
||||
}
|
||||
|
||||
impl $type {
|
||||
/// Maximum value the index can take, as a `u32`.
|
||||
$v const MAX_AS_U32: u32 = $max;
|
||||
|
||||
/// Maximum value the index can take.
|
||||
$v const MAX: Self = Self::from_u32($max);
|
||||
|
||||
/// Creates a new index from a given `usize`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// Will panic if `value` exceeds `MAX`.
|
||||
#[inline]
|
||||
$v const fn from_usize(value: usize) -> Self {
|
||||
assert!(value <= ($max as usize));
|
||||
// SAFETY: We just checked that `value <= max`.
|
||||
unsafe {
|
||||
Self::from_u32_unchecked(value as u32)
|
||||
}
|
||||
}
|
||||
|
||||
/// Creates a new index from a given `u32`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// Will panic if `value` exceeds `MAX`.
|
||||
#[inline]
|
||||
$v const fn from_u32(value: u32) -> Self {
|
||||
assert!(value <= $max);
|
||||
// SAFETY: We just checked that `value <= max`.
|
||||
unsafe {
|
||||
Self::from_u32_unchecked(value)
|
||||
}
|
||||
}
|
||||
|
||||
/// Creates a new index from a given `u32`.
|
||||
///
|
||||
/// # Safety
|
||||
///
|
||||
/// The provided value must be less than or equal to the maximum value for the newtype.
|
||||
/// Providing a value outside this range is undefined due to layout restrictions.
|
||||
///
|
||||
/// Prefer using `from_u32`.
|
||||
#[inline]
|
||||
$v const unsafe fn from_u32_unchecked(value: u32) -> Self {
|
||||
Self { private: value }
|
||||
}
|
||||
|
||||
/// Extracts the value of this index as a `usize`.
|
||||
#[inline]
|
||||
$v const fn index(self) -> usize {
|
||||
self.as_usize()
|
||||
}
|
||||
|
||||
/// Extracts the value of this index as a `u32`.
|
||||
#[inline]
|
||||
$v const fn as_u32(self) -> u32 {
|
||||
self.private
|
||||
}
|
||||
|
||||
/// Extracts the value of this index as a `usize`.
|
||||
#[inline]
|
||||
$v const fn as_usize(self) -> usize {
|
||||
self.as_u32() as usize
|
||||
}
|
||||
}
|
||||
|
||||
impl std::ops::Add<usize> for $type {
|
||||
type Output = Self;
|
||||
|
||||
fn add(self, other: usize) -> Self {
|
||||
Self::from_usize(self.index() + other)
|
||||
}
|
||||
}
|
||||
|
||||
impl $crate::vec::Idx for $type {
|
||||
#[inline]
|
||||
fn new(value: usize) -> Self {
|
||||
Self::from_usize(value)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
fn index(self) -> usize {
|
||||
self.as_usize()
|
||||
}
|
||||
}
|
||||
|
||||
impl ::std::iter::Step for $type {
|
||||
#[inline]
|
||||
fn steps_between(start: &Self, end: &Self) -> Option<usize> {
|
||||
<usize as ::std::iter::Step>::steps_between(
|
||||
&Self::index(*start),
|
||||
&Self::index(*end),
|
||||
)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
fn forward_checked(start: Self, u: usize) -> Option<Self> {
|
||||
Self::index(start).checked_add(u).map(Self::from_usize)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
fn backward_checked(start: Self, u: usize) -> Option<Self> {
|
||||
Self::index(start).checked_sub(u).map(Self::from_usize)
|
||||
}
|
||||
}
|
||||
|
||||
// Safety: The implementation of `Step` upholds all invariants.
|
||||
unsafe impl ::std::iter::TrustedStep for $type {}
|
||||
|
||||
impl From<$type> for u32 {
|
||||
#[inline]
|
||||
fn from(v: $type) -> u32 {
|
||||
v.as_u32()
|
||||
}
|
||||
}
|
||||
|
||||
impl From<$type> for usize {
|
||||
#[inline]
|
||||
fn from(v: $type) -> usize {
|
||||
v.as_usize()
|
||||
}
|
||||
}
|
||||
|
||||
impl From<usize> for $type {
|
||||
#[inline]
|
||||
fn from(value: usize) -> Self {
|
||||
Self::from_usize(value)
|
||||
}
|
||||
}
|
||||
|
||||
impl From<u32> for $type {
|
||||
#[inline]
|
||||
fn from(value: u32) -> Self {
|
||||
Self::from_u32(value)
|
||||
}
|
||||
}
|
||||
|
||||
$crate::newtype_index!(
|
||||
@handle_debug
|
||||
@derives [$($derives,)*]
|
||||
@type [$type]
|
||||
@debug_format [$debug_format]);
|
||||
);
|
||||
|
||||
// base case for handle_debug where format is custom. No Debug implementation is emitted.
|
||||
(@handle_debug
|
||||
@derives [$($_derives:ident,)*]
|
||||
@type [$type:ident]
|
||||
@debug_format [custom]) => ();
|
||||
|
||||
// base case for handle_debug, no debug overrides found, so use default
|
||||
(@handle_debug
|
||||
@derives []
|
||||
@type [$type:ident]
|
||||
@debug_format [$debug_format:tt]) => (
|
||||
impl ::std::fmt::Debug for $type {
|
||||
fn fmt(&self, fmt: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
|
||||
write!(fmt, $debug_format, self.as_u32())
|
||||
}
|
||||
}
|
||||
);
|
||||
|
||||
// Debug is requested for derive, don't generate any Debug implementation.
|
||||
(@handle_debug
|
||||
@derives [Debug, $($derives:ident,)*]
|
||||
@type [$type:ident]
|
||||
@debug_format [$debug_format:tt]) => ();
|
||||
|
||||
// It's not Debug, so just pop it off the front of the derives stack and check the rest.
|
||||
(@handle_debug
|
||||
@derives [$_derive:ident, $($derives:ident,)*]
|
||||
@type [$type:ident]
|
||||
@debug_format [$debug_format:tt]) => (
|
||||
$crate::newtype_index!(
|
||||
@handle_debug
|
||||
@derives [$($derives,)*]
|
||||
@type [$type]
|
||||
@debug_format [$debug_format]);
|
||||
);
|
||||
|
||||
// Append comma to end of derives list if it's missing
|
||||
(@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
derive [$($derives:ident),*]
|
||||
$($tokens:tt)*) => (
|
||||
$crate::newtype_index!(
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
derive [$($derives,)*]
|
||||
$($tokens)*);
|
||||
);
|
||||
|
||||
// By not including the @derives marker in this list nor in the default args, we can force it
|
||||
// to come first if it exists. When encodable is custom, just use the derives list as-is.
|
||||
(@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
derive [$($derives:ident,)+]
|
||||
ENCODABLE = custom
|
||||
$($tokens:tt)*) => (
|
||||
$crate::newtype_index!(
|
||||
@attrs [$(#[$attrs])*]
|
||||
@derives [$($derives,)+]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$($tokens)*);
|
||||
);
|
||||
|
||||
// By not including the @derives marker in this list nor in the default args, we can force it
|
||||
// to come first if it exists. When encodable isn't custom, add serialization traits by default.
|
||||
(@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
derive [$($derives:ident,)+]
|
||||
$($tokens:tt)*) => (
|
||||
$crate::newtype_index!(
|
||||
@derives [$($derives,)+]
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$($tokens)*);
|
||||
$crate::newtype_index!(@serializable $type);
|
||||
);
|
||||
|
||||
// The case where no derives are added, but encodable is overridden. Don't
|
||||
// derive serialization traits
|
||||
(@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
ENCODABLE = custom
|
||||
$($tokens:tt)*) => (
|
||||
$crate::newtype_index!(
|
||||
@derives []
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$($tokens)*);
|
||||
);
|
||||
|
||||
// The case where no derives are added, add serialization derives by default
|
||||
(@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
$($tokens:tt)*) => (
|
||||
$crate::newtype_index!(
|
||||
@derives []
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$($tokens)*);
|
||||
$crate::newtype_index!(@serializable $type);
|
||||
);
|
||||
|
||||
(@serializable $type:ident) => (
|
||||
impl<D: ::rustc_serialize::Decoder> ::rustc_serialize::Decodable<D> for $type {
|
||||
fn decode(d: &mut D) -> Self {
|
||||
Self::from_u32(d.read_u32())
|
||||
}
|
||||
}
|
||||
impl<E: ::rustc_serialize::Encoder> ::rustc_serialize::Encodable<E> for $type {
|
||||
fn encode(&self, e: &mut E) -> Result<(), E::Error> {
|
||||
e.emit_u32(self.private)
|
||||
}
|
||||
}
|
||||
);
|
||||
|
||||
// Rewrite final without comma to one that includes comma
|
||||
(@derives [$($derives:ident,)*]
|
||||
@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
$name:ident = $constant:expr) => (
|
||||
$crate::newtype_index!(
|
||||
@derives [$($derives,)*]
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$name = $constant,);
|
||||
);
|
||||
|
||||
// Rewrite final const without comma to one that includes comma
|
||||
(@derives [$($derives:ident,)*]
|
||||
@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
$(#[doc = $doc:expr])*
|
||||
const $name:ident = $constant:expr) => (
|
||||
$crate::newtype_index!(
|
||||
@derives [$($derives,)*]
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$(#[doc = $doc])* const $name = $constant,);
|
||||
);
|
||||
|
||||
// Replace existing default for max
|
||||
(@derives [$($derives:ident,)*]
|
||||
@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$_max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
MAX = $max:expr,
|
||||
$($tokens:tt)*) => (
|
||||
$crate::newtype_index!(
|
||||
@derives [$($derives,)*]
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$($tokens)*);
|
||||
);
|
||||
|
||||
// Replace existing default for debug_format
|
||||
(@derives [$($derives:ident,)*]
|
||||
@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$_debug_format:tt]
|
||||
DEBUG_FORMAT = $debug_format:tt,
|
||||
$($tokens:tt)*) => (
|
||||
$crate::newtype_index!(
|
||||
@derives [$($derives,)*]
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$($tokens)*);
|
||||
);
|
||||
|
||||
// Assign a user-defined constant
|
||||
(@derives [$($derives:ident,)*]
|
||||
@attrs [$(#[$attrs:meta])*]
|
||||
@type [$type:ident]
|
||||
@max [$max:expr]
|
||||
@vis [$v:vis]
|
||||
@debug_format [$debug_format:tt]
|
||||
$(#[doc = $doc:expr])*
|
||||
const $name:ident = $constant:expr,
|
||||
$($tokens:tt)*) => (
|
||||
$(#[doc = $doc])*
|
||||
$v const $name: $type = $type::from_u32($constant);
|
||||
$crate::newtype_index!(
|
||||
@derives [$($derives,)*]
|
||||
@attrs [$(#[$attrs])*]
|
||||
@type [$type]
|
||||
@max [$max]
|
||||
@vis [$v]
|
||||
@debug_format [$debug_format]
|
||||
$($tokens)*);
|
||||
);
|
||||
}
|
||||
|
||||
#[derive(Clone, PartialEq, Eq, Hash)]
|
||||
pub struct IndexVec<I: Idx, T> {
|
||||
pub raw: Vec<T>,
|
||||
|
@ -1,4 +1,5 @@
|
||||
#![feature(proc_macro_diagnostic)]
|
||||
#![feature(allow_internal_unstable)]
|
||||
#![allow(rustc::default_hash_types)]
|
||||
#![recursion_limit = "128"]
|
||||
|
||||
@ -8,6 +9,7 @@ use proc_macro::TokenStream;
|
||||
|
||||
mod hash_stable;
|
||||
mod lift;
|
||||
mod newtype;
|
||||
mod query;
|
||||
mod serialize;
|
||||
mod session_diagnostic;
|
||||
@ -24,6 +26,27 @@ pub fn symbols(input: TokenStream) -> TokenStream {
|
||||
symbols::symbols(input.into()).into()
|
||||
}
|
||||
|
||||
/// Creates a struct type `S` that can be used as an index with
|
||||
/// `IndexVec` and so on.
|
||||
///
|
||||
/// There are two ways of interacting with these indices:
|
||||
///
|
||||
/// - The `From` impls are the preferred way. So you can do
|
||||
/// `S::from(v)` with a `usize` or `u32`. And you can convert back
|
||||
/// to an integer with `u32::from(s)`.
|
||||
///
|
||||
/// - Alternatively, you can use the methods `S::new(v)` and `s.index()`
|
||||
/// to create/return a value.
|
||||
///
|
||||
/// Internally, the index uses a u32, so the index must not exceed
|
||||
/// `u32::MAX`. You can also customize things like the `Debug` impl,
|
||||
/// what traits are derived, and so forth via the macro.
|
||||
#[proc_macro]
|
||||
#[allow_internal_unstable(step_trait, rustc_attrs, trusted_step)]
|
||||
pub fn newtype_index(input: TokenStream) -> TokenStream {
|
||||
newtype::newtype(input).into()
|
||||
}
|
||||
|
||||
decl_derive!([HashStable, attributes(stable_hasher)] => hash_stable::hash_stable_derive);
|
||||
decl_derive!(
|
||||
[HashStable_Generic, attributes(stable_hasher)] =>
|
||||
|
324
compiler/rustc_macros/src/newtype.rs
Normal file
324
compiler/rustc_macros/src/newtype.rs
Normal file
@ -0,0 +1,324 @@
|
||||
use proc_macro2::{Span, TokenStream};
|
||||
use quote::quote;
|
||||
use syn::parse::*;
|
||||
use syn::punctuated::Punctuated;
|
||||
use syn::*;
|
||||
|
||||
mod kw {
|
||||
syn::custom_keyword!(derive);
|
||||
syn::custom_keyword!(DEBUG_FORMAT);
|
||||
syn::custom_keyword!(MAX);
|
||||
syn::custom_keyword!(ENCODABLE);
|
||||
syn::custom_keyword!(custom);
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
enum DebugFormat {
|
||||
// The user will provide a custom `Debug` impl, so we shouldn't generate
|
||||
// one
|
||||
Custom,
|
||||
// Use the specified format string in the generated `Debug` impl
|
||||
// By default, this is "{}"
|
||||
Format(String),
|
||||
}
|
||||
|
||||
// We parse the input and emit the output in a single step.
|
||||
// This field stores the final macro output
|
||||
struct Newtype(TokenStream);
|
||||
|
||||
impl Parse for Newtype {
|
||||
fn parse(input: ParseStream<'_>) -> Result<Self> {
|
||||
let attrs = input.call(Attribute::parse_outer)?;
|
||||
let vis: Visibility = input.parse()?;
|
||||
input.parse::<Token![struct]>()?;
|
||||
let name: Ident = input.parse()?;
|
||||
|
||||
let body;
|
||||
braced!(body in input);
|
||||
|
||||
// Any additional `#[derive]` macro paths to apply
|
||||
let mut derive_paths: Option<Vec<Path>> = None;
|
||||
let mut debug_format: Option<DebugFormat> = None;
|
||||
let mut max = None;
|
||||
let mut consts = Vec::new();
|
||||
let mut encodable = true;
|
||||
|
||||
// Parse an optional trailing comma
|
||||
let try_comma = || -> Result<()> {
|
||||
if body.lookahead1().peek(Token![,]) {
|
||||
body.parse::<Token![,]>()?;
|
||||
}
|
||||
Ok(())
|
||||
};
|
||||
|
||||
if body.lookahead1().peek(Token![..]) {
|
||||
body.parse::<Token![..]>()?;
|
||||
} else {
|
||||
loop {
|
||||
if body.lookahead1().peek(kw::derive) {
|
||||
body.parse::<kw::derive>()?;
|
||||
let derives;
|
||||
bracketed!(derives in body);
|
||||
let derives: Punctuated<Path, Token![,]> =
|
||||
derives.parse_terminated(Path::parse)?;
|
||||
try_comma()?;
|
||||
if let Some(old) = derive_paths.replace(derives.into_iter().collect()) {
|
||||
panic!("Specified multiple derives: {:?}", old);
|
||||
}
|
||||
continue;
|
||||
}
|
||||
if body.lookahead1().peek(kw::DEBUG_FORMAT) {
|
||||
body.parse::<kw::DEBUG_FORMAT>()?;
|
||||
body.parse::<Token![=]>()?;
|
||||
if body.lookahead1().peek(kw::custom) {
|
||||
body.parse::<kw::custom>()?;
|
||||
if let Some(old) = debug_format.replace(DebugFormat::Custom) {
|
||||
panic!("Specified multiple debug format options: {:?}", old);
|
||||
}
|
||||
} else {
|
||||
let format_str: LitStr = body.parse()?;
|
||||
if let Some(old) =
|
||||
debug_format.replace(DebugFormat::Format(format_str.value()))
|
||||
{
|
||||
panic!("Specified multiple debug format options: {:?}", old);
|
||||
}
|
||||
}
|
||||
try_comma()?;
|
||||
continue;
|
||||
}
|
||||
if body.lookahead1().peek(kw::MAX) {
|
||||
body.parse::<kw::MAX>()?;
|
||||
body.parse::<Token![=]>()?;
|
||||
let val: Lit = body.parse()?;
|
||||
try_comma()?;
|
||||
if let Some(old) = max.replace(val) {
|
||||
panic!("Specified multiple MAX: {:?}", old);
|
||||
}
|
||||
continue;
|
||||
}
|
||||
if body.lookahead1().peek(kw::ENCODABLE) {
|
||||
body.parse::<kw::ENCODABLE>()?;
|
||||
body.parse::<Token![=]>()?;
|
||||
body.parse::<kw::custom>()?;
|
||||
try_comma()?;
|
||||
encodable = false;
|
||||
continue;
|
||||
}
|
||||
|
||||
// We've parsed everything that the user provided, so we're done
|
||||
if body.is_empty() {
|
||||
break;
|
||||
}
|
||||
|
||||
// Otherwise, we are parsng a user-defined constant
|
||||
let const_attrs = body.call(Attribute::parse_outer)?;
|
||||
body.parse::<Token![const]>()?;
|
||||
let const_name: Ident = body.parse()?;
|
||||
body.parse::<Token![=]>()?;
|
||||
let const_val: Expr = body.parse()?;
|
||||
try_comma()?;
|
||||
consts.push(quote! { #(#const_attrs)* #vis const #const_name: #name = #name::from_u32(#const_val); });
|
||||
}
|
||||
}
|
||||
|
||||
let derive_paths = derive_paths.unwrap_or_else(Vec::new);
|
||||
let debug_format = debug_format.unwrap_or(DebugFormat::Format("{}".to_string()));
|
||||
// shave off 256 indices at the end to allow space for packing these indices into enums
|
||||
let max = max.unwrap_or_else(|| Lit::Int(LitInt::new("0xFFFF_FF00", Span::call_site())));
|
||||
|
||||
let encodable_impls = if encodable {
|
||||
quote! {
|
||||
impl<D: ::rustc_serialize::Decoder> ::rustc_serialize::Decodable<D> for #name {
|
||||
fn decode(d: &mut D) -> Self {
|
||||
Self::from_u32(d.read_u32())
|
||||
}
|
||||
}
|
||||
impl<E: ::rustc_serialize::Encoder> ::rustc_serialize::Encodable<E> for #name {
|
||||
fn encode(&self, e: &mut E) -> Result<(), E::Error> {
|
||||
e.emit_u32(self.private)
|
||||
}
|
||||
}
|
||||
}
|
||||
} else {
|
||||
quote! {}
|
||||
};
|
||||
|
||||
let debug_impl = match debug_format {
|
||||
DebugFormat::Custom => quote! {},
|
||||
DebugFormat::Format(format) => {
|
||||
quote! {
|
||||
impl ::std::fmt::Debug for #name {
|
||||
fn fmt(&self, fmt: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
|
||||
write!(fmt, #format, self.as_u32())
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
Ok(Self(quote! {
|
||||
#(#attrs)*
|
||||
#[derive(Copy, PartialEq, Eq, Hash, PartialOrd, Ord, #(#derive_paths),*)]
|
||||
#[rustc_layout_scalar_valid_range_end(#max)]
|
||||
#vis struct #name {
|
||||
private: u32,
|
||||
}
|
||||
|
||||
#(#consts)*
|
||||
|
||||
impl Clone for #name {
|
||||
#[inline]
|
||||
fn clone(&self) -> Self {
|
||||
*self
|
||||
}
|
||||
}
|
||||
|
||||
impl #name {
|
||||
/// Maximum value the index can take, as a `u32`.
|
||||
#vis const MAX_AS_U32: u32 = #max;
|
||||
|
||||
/// Maximum value the index can take.
|
||||
#vis const MAX: Self = Self::from_u32(#max);
|
||||
|
||||
/// Creates a new index from a given `usize`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// Will panic if `value` exceeds `MAX`.
|
||||
#[inline]
|
||||
#vis const fn from_usize(value: usize) -> Self {
|
||||
assert!(value <= (#max as usize));
|
||||
// SAFETY: We just checked that `value <= max`.
|
||||
unsafe {
|
||||
Self::from_u32_unchecked(value as u32)
|
||||
}
|
||||
}
|
||||
|
||||
/// Creates a new index from a given `u32`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// Will panic if `value` exceeds `MAX`.
|
||||
#[inline]
|
||||
#vis const fn from_u32(value: u32) -> Self {
|
||||
assert!(value <= #max);
|
||||
// SAFETY: We just checked that `value <= max`.
|
||||
unsafe {
|
||||
Self::from_u32_unchecked(value)
|
||||
}
|
||||
}
|
||||
|
||||
/// Creates a new index from a given `u32`.
|
||||
///
|
||||
/// # Safety
|
||||
///
|
||||
/// The provided value must be less than or equal to the maximum value for the newtype.
|
||||
/// Providing a value outside this range is undefined due to layout restrictions.
|
||||
///
|
||||
/// Prefer using `from_u32`.
|
||||
#[inline]
|
||||
#vis const unsafe fn from_u32_unchecked(value: u32) -> Self {
|
||||
Self { private: value }
|
||||
}
|
||||
|
||||
/// Extracts the value of this index as a `usize`.
|
||||
#[inline]
|
||||
#vis const fn index(self) -> usize {
|
||||
self.as_usize()
|
||||
}
|
||||
|
||||
/// Extracts the value of this index as a `u32`.
|
||||
#[inline]
|
||||
#vis const fn as_u32(self) -> u32 {
|
||||
self.private
|
||||
}
|
||||
|
||||
/// Extracts the value of this index as a `usize`.
|
||||
#[inline]
|
||||
#vis const fn as_usize(self) -> usize {
|
||||
self.as_u32() as usize
|
||||
}
|
||||
}
|
||||
|
||||
impl std::ops::Add<usize> for #name {
|
||||
type Output = Self;
|
||||
|
||||
fn add(self, other: usize) -> Self {
|
||||
Self::from_usize(self.index() + other)
|
||||
}
|
||||
}
|
||||
|
||||
impl rustc_index::vec::Idx for #name {
|
||||
#[inline]
|
||||
fn new(value: usize) -> Self {
|
||||
Self::from_usize(value)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
fn index(self) -> usize {
|
||||
self.as_usize()
|
||||
}
|
||||
}
|
||||
|
||||
impl ::std::iter::Step for #name {
|
||||
#[inline]
|
||||
fn steps_between(start: &Self, end: &Self) -> Option<usize> {
|
||||
<usize as ::std::iter::Step>::steps_between(
|
||||
&Self::index(*start),
|
||||
&Self::index(*end),
|
||||
)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
fn forward_checked(start: Self, u: usize) -> Option<Self> {
|
||||
Self::index(start).checked_add(u).map(Self::from_usize)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
fn backward_checked(start: Self, u: usize) -> Option<Self> {
|
||||
Self::index(start).checked_sub(u).map(Self::from_usize)
|
||||
}
|
||||
}
|
||||
|
||||
// Safety: The implementation of `Step` upholds all invariants.
|
||||
unsafe impl ::std::iter::TrustedStep for #name {}
|
||||
|
||||
impl From<#name> for u32 {
|
||||
#[inline]
|
||||
fn from(v: #name) -> u32 {
|
||||
v.as_u32()
|
||||
}
|
||||
}
|
||||
|
||||
impl From<#name> for usize {
|
||||
#[inline]
|
||||
fn from(v: #name) -> usize {
|
||||
v.as_usize()
|
||||
}
|
||||
}
|
||||
|
||||
impl From<usize> for #name {
|
||||
#[inline]
|
||||
fn from(value: usize) -> Self {
|
||||
Self::from_usize(value)
|
||||
}
|
||||
}
|
||||
|
||||
impl From<u32> for #name {
|
||||
#[inline]
|
||||
fn from(value: u32) -> Self {
|
||||
Self::from_u32(value)
|
||||
}
|
||||
}
|
||||
|
||||
#encodable_impls
|
||||
#debug_impl
|
||||
|
||||
}))
|
||||
}
|
||||
}
|
||||
|
||||
pub fn newtype(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
|
||||
let input = parse_macro_input!(input as Newtype);
|
||||
input.0.into()
|
||||
}
|
Loading…
Reference in New Issue
Block a user