rust/src/skip.rs

128 lines
3.6 KiB
Rust

//! Module that contains skip related stuffs.
use rustc_ast::ast;
use rustc_ast_pretty::pprust;
use std::collections::HashSet;
/// Track which blocks of code are to be skipped when formatting.
///
/// You can update it by:
///
/// - attributes slice
/// - manually feeding values into the underlying contexts
///
/// Query this context to know if you need to skip a block.
#[derive(Default, Clone)]
pub(crate) struct SkipContext {
pub(crate) macros: SkipNameContext,
pub(crate) attributes: SkipNameContext,
}
impl SkipContext {
pub(crate) fn update_with_attrs(&mut self, attrs: &[ast::Attribute]) {
self.macros.extend(get_skip_names("macros", attrs));
self.attributes.extend(get_skip_names("attributes", attrs));
}
pub(crate) fn update(&mut self, other: SkipContext) {
let SkipContext { macros, attributes } = other;
self.macros.update(macros);
self.attributes.update(attributes);
}
}
/// Track which names to skip.
///
/// Query this context with a string to know whether to skip it.
#[derive(Clone)]
pub(crate) enum SkipNameContext {
All,
Values(HashSet<String>),
}
impl Default for SkipNameContext {
fn default() -> Self {
Self::Values(Default::default())
}
}
impl Extend<String> for SkipNameContext {
fn extend<T: IntoIterator<Item = String>>(&mut self, iter: T) {
match self {
Self::All => {}
Self::Values(values) => values.extend(iter),
}
}
}
impl SkipNameContext {
pub(crate) fn update(&mut self, other: Self) {
match (self, other) {
// If we're already skipping everything, nothing more can be added
(Self::All, _) => {}
// If we want to skip all, set it
(this, Self::All) => {
*this = Self::All;
}
// If we have some new values to skip, add them
(Self::Values(existing_values), Self::Values(new_values)) => {
existing_values.extend(new_values)
}
}
}
pub(crate) fn skip(&self, name: &str) -> bool {
match self {
Self::All => true,
Self::Values(values) => values.contains(name),
}
}
pub(crate) fn skip_all(&mut self) {
*self = Self::All;
}
}
static RUSTFMT: &str = "rustfmt";
static SKIP: &str = "skip";
/// Say if you're playing with `rustfmt`'s skip attribute
pub(crate) fn is_skip_attr(segments: &[ast::PathSegment]) -> bool {
if segments.len() < 2 || segments[0].ident.to_string() != RUSTFMT {
return false;
}
match segments.len() {
2 => segments[1].ident.to_string() == SKIP,
3 => {
segments[1].ident.to_string() == SKIP
&& ["macros", "attributes"]
.iter()
.any(|&n| n == pprust::path_segment_to_string(&segments[2]))
}
_ => false,
}
}
fn get_skip_names(kind: &str, attrs: &[ast::Attribute]) -> Vec<String> {
let mut skip_names = vec![];
let path = format!("{RUSTFMT}::{SKIP}::{kind}");
for attr in attrs {
// rustc_ast::ast::Path is implemented partialEq
// but it is designed for segments.len() == 1
if let ast::AttrKind::Normal(normal) = &attr.kind {
if pprust::path_to_string(&normal.item.path) != path {
continue;
}
}
if let Some(list) = attr.meta_item_list() {
for nested_meta_item in list {
if let Some(name) = nested_meta_item.ident() {
skip_names.push(name.to_string());
}
}
}
}
skip_names
}