use crate::GLOBALS;
use crate::Span;
use crate::edition::Edition;
use crate::symbol::{kw, Symbol};
use serialize::{Encodable, Decodable, Encoder, Decoder};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::sync::Lrc;
use std::{fmt, mem};
#[derive(Clone, Copy, PartialEq, Eq, Default, PartialOrd, Ord, Hash)]
pub struct SyntaxContext(u32);
#[derive(Copy, Clone, Debug)]
struct SyntaxContextData {
outer_mark: Mark,
transparency: Transparency,
prev_ctxt: SyntaxContext,
opaque: SyntaxContext,
opaque_and_semitransparent: SyntaxContext,
dollar_crate_name: Symbol,
}
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
pub struct Mark(u32);
#[derive(Clone, Debug)]
struct MarkData {
parent: Mark,
default_transparency: Transparency,
expn_info: Option<ExpnInfo>,
}
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Hash, Debug)]
pub enum Transparency {
Transparent,
SemiTransparent,
Opaque,
}
impl Mark {
pub fn fresh(parent: Mark) -> Self {
HygieneData::with(|data| {
data.marks.push(MarkData {
parent,
default_transparency: Transparency::SemiTransparent,
expn_info: None,
});
Mark(data.marks.len() as u32 - 1)
})
}
#[inline]
pub fn root() -> Self {
Mark(0)
}
#[inline]
pub fn as_u32(self) -> u32 {
self.0
}
#[inline]
pub fn from_u32(raw: u32) -> Mark {
Mark(raw)
}
#[inline]
pub fn parent(self) -> Mark {
HygieneData::with(|data| data.marks[self.0 as usize].parent)
}
#[inline]
pub fn expn_info(self) -> Option<ExpnInfo> {
HygieneData::with(|data| data.marks[self.0 as usize].expn_info.clone())
}
#[inline]
pub fn set_expn_info(self, info: ExpnInfo) {
HygieneData::with(|data| data.marks[self.0 as usize].expn_info = Some(info))
}
#[inline]
pub fn set_default_transparency(self, transparency: Transparency) {
assert_ne!(self, Mark::root());
HygieneData::with(|data| data.marks[self.0 as usize].default_transparency = transparency)
}
pub fn is_descendant_of(self, ancestor: Mark) -> bool {
HygieneData::with(|data| data.is_descendant_of(self, ancestor))
}
pub fn outer_is_descendant_of(self, ctxt: SyntaxContext) -> bool {
HygieneData::with(|data| data.is_descendant_of(self, data.outer(ctxt)))
}
pub fn least_ancestor(mut a: Mark, mut b: Mark) -> Mark {
HygieneData::with(|data| {
let mut a_path = FxHashSet::<Mark>::default();
while a != Mark::root() {
a_path.insert(a);
a = data.marks[a.0 as usize].parent;
}
while !a_path.contains(&b) {
b = data.marks[b.0 as usize].parent;
}
b
})
}
#[inline]
pub fn looks_like_proc_macro_derive(self) -> bool {
HygieneData::with(|data| {
let mark_data = &data.marks[self.0 as usize];
if mark_data.default_transparency == Transparency::Opaque {
if let Some(expn_info) = &mark_data.expn_info {
if let ExpnFormat::MacroAttribute(name) = expn_info.format {
if name.as_str().starts_with("derive(") {
return true;
}
}
}
}
false
})
}
}
#[derive(Debug)]
crate struct HygieneData {
marks: Vec<MarkData>,
syntax_contexts: Vec<SyntaxContextData>,
markings: FxHashMap<(SyntaxContext, Mark, Transparency), SyntaxContext>,
}
impl HygieneData {
crate fn new() -> Self {
HygieneData {
marks: vec![MarkData {
parent: Mark::root(),
default_transparency: Transparency::Opaque,
expn_info: None,
}],
syntax_contexts: vec![SyntaxContextData {
outer_mark: Mark::root(),
transparency: Transparency::Opaque,
prev_ctxt: SyntaxContext(0),
opaque: SyntaxContext(0),
opaque_and_semitransparent: SyntaxContext(0),
dollar_crate_name: kw::DollarCrate,
}],
markings: FxHashMap::default(),
}
}
fn with<T, F: FnOnce(&mut HygieneData) -> T>(f: F) -> T {
GLOBALS.with(|globals| f(&mut *globals.hygiene_data.borrow_mut()))
}
fn outer(&self, ctxt: SyntaxContext) -> Mark {
self.syntax_contexts[ctxt.0 as usize].outer_mark
}
fn expn_info(&self, mark: Mark) -> Option<ExpnInfo> {
self.marks[mark.0 as usize].expn_info.clone()
}
fn is_descendant_of(&self, mut mark: Mark, ancestor: Mark) -> bool {
while mark != ancestor {
if mark == Mark::root() {
return false;
}
mark = self.marks[mark.0 as usize].parent;
}
true
}
}
pub fn clear_markings() {
HygieneData::with(|data| data.markings = FxHashMap::default());
}
impl SyntaxContext {
#[inline]
pub const fn empty() -> Self {
SyntaxContext(0)
}
#[inline]
crate fn as_u32(self) -> u32 {
self.0
}
#[inline]
crate fn from_u32(raw: u32) -> SyntaxContext {
SyntaxContext(raw)
}
pub fn allocate_directly(expansion_info: ExpnInfo) -> Self {
HygieneData::with(|data| {
data.marks.push(MarkData {
parent: Mark::root(),
default_transparency: Transparency::SemiTransparent,
expn_info: Some(expansion_info),
});
let mark = Mark(data.marks.len() as u32 - 1);
data.syntax_contexts.push(SyntaxContextData {
outer_mark: mark,
transparency: Transparency::SemiTransparent,
prev_ctxt: SyntaxContext::empty(),
opaque: SyntaxContext::empty(),
opaque_and_semitransparent: SyntaxContext::empty(),
dollar_crate_name: kw::DollarCrate,
});
SyntaxContext(data.syntax_contexts.len() as u32 - 1)
})
}
pub fn apply_mark(self, mark: Mark) -> SyntaxContext {
assert_ne!(mark, Mark::root());
self.apply_mark_with_transparency(
mark, HygieneData::with(|data| data.marks[mark.0 as usize].default_transparency)
)
}
pub fn apply_mark_with_transparency(self, mark: Mark, transparency: Transparency)
-> SyntaxContext {
assert_ne!(mark, Mark::root());
if transparency == Transparency::Opaque {
return self.apply_mark_internal(mark, transparency);
}
let call_site_ctxt =
mark.expn_info().map_or(SyntaxContext::empty(), |info| info.call_site.ctxt());
let call_site_ctxt = if transparency == Transparency::SemiTransparent {
call_site_ctxt.modern()
} else {
call_site_ctxt.modern_and_legacy()
};
if call_site_ctxt == SyntaxContext::empty() {
return self.apply_mark_internal(mark, transparency);
}
let mut ctxt = call_site_ctxt;
for (mark, transparency) in self.marks() {
ctxt = ctxt.apply_mark_internal(mark, transparency);
}
ctxt.apply_mark_internal(mark, transparency)
}
fn apply_mark_internal(self, mark: Mark, transparency: Transparency) -> SyntaxContext {
HygieneData::with(|data| {
let syntax_contexts = &mut data.syntax_contexts;
let mut opaque = syntax_contexts[self.0 as usize].opaque;
let mut opaque_and_semitransparent =
syntax_contexts[self.0 as usize].opaque_and_semitransparent;
if transparency >= Transparency::Opaque {
let prev_ctxt = opaque;
opaque = *data.markings.entry((prev_ctxt, mark, transparency)).or_insert_with(|| {
let new_opaque = SyntaxContext(syntax_contexts.len() as u32);
syntax_contexts.push(SyntaxContextData {
outer_mark: mark,
transparency,
prev_ctxt,
opaque: new_opaque,
opaque_and_semitransparent: new_opaque,
dollar_crate_name: kw::DollarCrate,
});
new_opaque
});
}
if transparency >= Transparency::SemiTransparent {
let prev_ctxt = opaque_and_semitransparent;
opaque_and_semitransparent =
*data.markings.entry((prev_ctxt, mark, transparency)).or_insert_with(|| {
let new_opaque_and_semitransparent =
SyntaxContext(syntax_contexts.len() as u32);
syntax_contexts.push(SyntaxContextData {
outer_mark: mark,
transparency,
prev_ctxt,
opaque,
opaque_and_semitransparent: new_opaque_and_semitransparent,
dollar_crate_name: kw::DollarCrate,
});
new_opaque_and_semitransparent
});
}
let prev_ctxt = self;
*data.markings.entry((prev_ctxt, mark, transparency)).or_insert_with(|| {
let new_opaque_and_semitransparent_and_transparent =
SyntaxContext(syntax_contexts.len() as u32);
syntax_contexts.push(SyntaxContextData {
outer_mark: mark,
transparency,
prev_ctxt,
opaque,
opaque_and_semitransparent,
dollar_crate_name: kw::DollarCrate,
});
new_opaque_and_semitransparent_and_transparent
})
})
}
pub fn remove_mark(&mut self) -> Mark {
HygieneData::with(|data| {
let outer_mark = data.syntax_contexts[self.0 as usize].outer_mark;
*self = data.syntax_contexts[self.0 as usize].prev_ctxt;
outer_mark
})
}
pub fn marks(mut self) -> Vec<(Mark, Transparency)> {
HygieneData::with(|data| {
let mut marks = Vec::new();
while self != SyntaxContext::empty() {
let ctxt_data = &data.syntax_contexts[self.0 as usize];
marks.push((ctxt_data.outer_mark, ctxt_data.transparency));
self = ctxt_data.prev_ctxt;
}
marks.reverse();
marks
})
}
pub fn adjust(&mut self, expansion: Mark) -> Option<Mark> {
let mut scope = None;
while !expansion.outer_is_descendant_of(*self) {
scope = Some(self.remove_mark());
}
scope
}
pub fn glob_adjust(&mut self, expansion: Mark, mut glob_ctxt: SyntaxContext)
-> Option<Option<Mark>> {
let mut scope = None;
while !expansion.outer_is_descendant_of(glob_ctxt) {
scope = Some(glob_ctxt.remove_mark());
if self.remove_mark() != scope.unwrap() {
return None;
}
}
if self.adjust(expansion).is_some() {
return None;
}
Some(scope)
}
pub fn reverse_glob_adjust(&mut self, expansion: Mark, mut glob_ctxt: SyntaxContext)
-> Option<Option<Mark>> {
if self.adjust(expansion).is_some() {
return None;
}
let mut marks = Vec::new();
while !expansion.outer_is_descendant_of(glob_ctxt) {
marks.push(glob_ctxt.remove_mark());
}
let scope = marks.last().cloned();
while let Some(mark) = marks.pop() {
*self = self.apply_mark(mark);
}
Some(scope)
}
#[inline]
pub fn modern(self) -> SyntaxContext {
HygieneData::with(|data| data.syntax_contexts[self.0 as usize].opaque)
}
#[inline]
pub fn modern_and_legacy(self) -> SyntaxContext {
HygieneData::with(|data| data.syntax_contexts[self.0 as usize].opaque_and_semitransparent)
}
#[inline]
pub fn outer(self) -> Mark {
HygieneData::with(|data| data.outer(self))
}
#[inline]
pub fn outer_expn_info(self) -> Option<ExpnInfo> {
HygieneData::with(|data| data.expn_info(data.outer(self)))
}
pub fn dollar_crate_name(self) -> Symbol {
HygieneData::with(|data| data.syntax_contexts[self.0 as usize].dollar_crate_name)
}
pub fn set_dollar_crate_name(self, dollar_crate_name: Symbol) {
HygieneData::with(|data| {
let prev_dollar_crate_name = mem::replace(
&mut data.syntax_contexts[self.0 as usize].dollar_crate_name, dollar_crate_name
);
assert!(dollar_crate_name == prev_dollar_crate_name ||
prev_dollar_crate_name == kw::DollarCrate,
"$crate name is reset for a syntax context");
})
}
}
impl fmt::Debug for SyntaxContext {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "#{}", self.0)
}
}
#[derive(Clone, Hash, Debug, RustcEncodable, RustcDecodable)]
pub struct ExpnInfo {
pub call_site: Span,
pub def_site: Option<Span>,
pub format: ExpnFormat,
pub allow_internal_unstable: Option<Lrc<[Symbol]>>,
pub allow_internal_unsafe: bool,
pub local_inner_macros: bool,
pub edition: Edition,
}
#[derive(Clone, Hash, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
pub enum ExpnFormat {
MacroAttribute(Symbol),
MacroBang(Symbol),
CompilerDesugaring(CompilerDesugaringKind)
}
impl ExpnFormat {
pub fn name(&self) -> Symbol {
match *self {
ExpnFormat::MacroBang(name) | ExpnFormat::MacroAttribute(name) => name,
ExpnFormat::CompilerDesugaring(kind) => kind.name(),
}
}
}
#[derive(Clone, Copy, Hash, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
pub enum CompilerDesugaringKind {
IfTemporary,
QuestionMark,
TryBlock,
ExistentialReturnType,
Async,
Await,
ForLoop,
}
impl CompilerDesugaringKind {
pub fn name(self) -> Symbol {
Symbol::intern(match self {
CompilerDesugaringKind::IfTemporary => "if",
CompilerDesugaringKind::Async => "async",
CompilerDesugaringKind::Await => "await",
CompilerDesugaringKind::QuestionMark => "?",
CompilerDesugaringKind::TryBlock => "try block",
CompilerDesugaringKind::ExistentialReturnType => "existential type",
CompilerDesugaringKind::ForLoop => "for loop",
})
}
}
impl Encodable for SyntaxContext {
fn encode<E: Encoder>(&self, _: &mut E) -> Result<(), E::Error> {
Ok(())
}
}
impl Decodable for SyntaxContext {
fn decode<D: Decoder>(_: &mut D) -> Result<SyntaxContext, D::Error> {
Ok(SyntaxContext::empty())
}
}