use crate::errors::{InvalidMetaItem, SuffixedLiteralInAttribute};
use crate::fluent_generated as fluent;
use super::{AttrWrapper, Capturing, FnParseMode, ForceCollect, Parser, PathStyle};
use rustc_ast as ast;
use rustc_ast::attr;
use rustc_ast::token::{self, Delimiter, Nonterminal};
use rustc_errors::{error_code, Diagnostic, IntoDiagnostic, PResult};
use rustc_span::{sym, BytePos, Span};
use std::convert::TryInto;
use thin_vec::ThinVec;
use tracing::debug;
#[derive(Debug)]
pub enum InnerAttrPolicy {
Permitted,
Forbidden(Option<InnerAttrForbiddenReason>),
}
#[derive(Clone, Copy, Debug)]
pub enum InnerAttrForbiddenReason {
InCodeBlock,
AfterOuterDocComment { prev_doc_comment_span: Span },
AfterOuterAttribute { prev_outer_attr_sp: Span },
}
enum OuterAttributeType {
DocComment,
DocBlockComment,
Attribute,
}
impl<'a> Parser<'a> {
pub(super) fn parse_outer_attributes(&mut self) -> PResult<'a, AttrWrapper> {
let mut outer_attrs = ast::AttrVec::new();
let mut just_parsed_doc_comment = false;
let start_pos = self.num_bump_calls;
loop {
let attr = if self.check(&token::Pound) {
let prev_outer_attr_sp = outer_attrs.last().map(|attr| attr.span);
let inner_error_reason = if just_parsed_doc_comment {
Some(InnerAttrForbiddenReason::AfterOuterDocComment {
prev_doc_comment_span: prev_outer_attr_sp.unwrap(),
})
} else {
prev_outer_attr_sp.map(|prev_outer_attr_sp| {
InnerAttrForbiddenReason::AfterOuterAttribute { prev_outer_attr_sp }
})
};
let inner_parse_policy = InnerAttrPolicy::Forbidden(inner_error_reason);
just_parsed_doc_comment = false;
Some(self.parse_attribute(inner_parse_policy)?)
} else if let token::DocComment(comment_kind, attr_style, data) = self.token.kind {
if attr_style != ast::AttrStyle::Outer {
let span = self.token.span;
let mut err = self.sess.span_diagnostic.struct_span_err_with_code(
span,
fluent::parse_inner_doc_comment_not_permitted,
error_code!(E0753),
);
if let Some(replacement_span) = self.annotate_following_item_if_applicable(
&mut err,
span,
match comment_kind {
token::CommentKind::Line => OuterAttributeType::DocComment,
token::CommentKind::Block => OuterAttributeType::DocBlockComment,
},
) {
err.note(fluent::parse_note);
err.span_suggestion_verbose(
replacement_span,
fluent::parse_suggestion,
"",
rustc_errors::Applicability::MachineApplicable,
);
}
err.emit();
}
self.bump();
just_parsed_doc_comment = true;
Some(attr::mk_doc_comment(
&self.sess.attr_id_generator,
comment_kind,
ast::AttrStyle::Outer,
data,
self.prev_token.span,
))
} else {
None
};
if let Some(attr) = attr {
if attr.style == ast::AttrStyle::Outer {
outer_attrs.push(attr);
}
} else {
break;
}
}
Ok(AttrWrapper::new(outer_attrs, start_pos))
}
pub fn parse_attribute(
&mut self,
inner_parse_policy: InnerAttrPolicy,
) -> PResult<'a, ast::Attribute> {
debug!(
"parse_attribute: inner_parse_policy={:?} self.token={:?}",
inner_parse_policy, self.token
);
let lo = self.token.span;
self.collect_tokens_no_attrs(|this| {
assert!(this.eat(&token::Pound), "parse_attribute called in non-attribute position");
let style =
if this.eat(&token::Not) { ast::AttrStyle::Inner } else { ast::AttrStyle::Outer };
this.expect(&token::OpenDelim(Delimiter::Bracket))?;
let item = this.parse_attr_item(false)?;
this.expect(&token::CloseDelim(Delimiter::Bracket))?;
let attr_sp = lo.to(this.prev_token.span);
if style == ast::AttrStyle::Inner {
this.error_on_forbidden_inner_attr(attr_sp, inner_parse_policy);
}
Ok(attr::mk_attr_from_item(&self.sess.attr_id_generator, item, None, style, attr_sp))
})
}
fn annotate_following_item_if_applicable(
&self,
err: &mut Diagnostic,
span: Span,
attr_type: OuterAttributeType,
) -> Option<Span> {
let mut snapshot = self.create_snapshot_for_diagnostic();
let lo = span.lo()
+ BytePos(match attr_type {
OuterAttributeType::Attribute => 1,
_ => 2,
});
let hi = lo + BytePos(1);
let replacement_span = span.with_lo(lo).with_hi(hi);
if let OuterAttributeType::DocBlockComment | OuterAttributeType::DocComment = attr_type {
snapshot.bump();
}
loop {
if snapshot.token.kind == token::Pound {
if let Err(err) = snapshot.parse_attribute(InnerAttrPolicy::Permitted) {
err.cancel();
return Some(replacement_span);
}
} else {
break;
}
}
match snapshot.parse_item_common(
AttrWrapper::empty(),
true,
false,
FnParseMode { req_name: |_| true, req_body: true },
ForceCollect::No,
) {
Ok(Some(item)) => {
err.set_arg("item", item.kind.descr());
err.span_label(item.span, fluent::parse_label_does_not_annotate_this);
err.span_suggestion_verbose(
replacement_span,
fluent::parse_sugg_change_inner_to_outer,
match attr_type {
OuterAttributeType::Attribute => "",
OuterAttributeType::DocBlockComment => "*",
OuterAttributeType::DocComment => "/",
},
rustc_errors::Applicability::MachineApplicable,
);
return None;
}
Err(item_err) => {
item_err.cancel();
}
Ok(None) => {}
}
Some(replacement_span)
}
pub(super) fn error_on_forbidden_inner_attr(&self, attr_sp: Span, policy: InnerAttrPolicy) {
if let InnerAttrPolicy::Forbidden(reason) = policy {
let mut diag = match reason.as_ref().copied() {
Some(InnerAttrForbiddenReason::AfterOuterDocComment { prev_doc_comment_span }) => {
let mut diag = self.struct_span_err(
attr_sp,
fluent::parse_inner_attr_not_permitted_after_outer_doc_comment,
);
diag.span_label(attr_sp, fluent::parse_label_attr)
.span_label(prev_doc_comment_span, fluent::parse_label_prev_doc_comment);
diag
}
Some(InnerAttrForbiddenReason::AfterOuterAttribute { prev_outer_attr_sp }) => {
let mut diag = self.struct_span_err(
attr_sp,
fluent::parse_inner_attr_not_permitted_after_outer_attr,
);
diag.span_label(attr_sp, fluent::parse_label_attr)
.span_label(prev_outer_attr_sp, fluent::parse_label_prev_attr);
diag
}
Some(InnerAttrForbiddenReason::InCodeBlock) | None => {
self.struct_span_err(attr_sp, fluent::parse_inner_attr_not_permitted)
}
};
diag.note(fluent::parse_inner_attr_explanation);
if self
.annotate_following_item_if_applicable(
&mut diag,
attr_sp,
OuterAttributeType::Attribute,
)
.is_some()
{
diag.note(fluent::parse_outer_attr_explanation);
};
diag.emit();
}
}
pub fn parse_attr_item(&mut self, capture_tokens: bool) -> PResult<'a, ast::AttrItem> {
let item = match &self.token.kind {
token::Interpolated(nt) => match &**nt {
Nonterminal::NtMeta(item) => Some(item.clone().into_inner()),
_ => None,
},
_ => None,
};
Ok(if let Some(item) = item {
self.bump();
item
} else {
let do_parse = |this: &mut Self| {
let path = this.parse_path(PathStyle::Mod)?;
let args = this.parse_attr_args()?;
Ok(ast::AttrItem { path, args, tokens: None })
};
if capture_tokens { self.collect_tokens_no_attrs(do_parse) } else { do_parse(self) }?
})
}
pub(crate) fn parse_inner_attributes(&mut self) -> PResult<'a, ast::AttrVec> {
let mut attrs = ast::AttrVec::new();
loop {
let start_pos: u32 = self.num_bump_calls.try_into().unwrap();
let attr = if self.check(&token::Pound) && self.look_ahead(1, |t| t == &token::Not) {
Some(self.parse_attribute(InnerAttrPolicy::Permitted)?)
} else if let token::DocComment(comment_kind, attr_style, data) = self.token.kind {
if attr_style == ast::AttrStyle::Inner {
self.bump();
Some(attr::mk_doc_comment(
&self.sess.attr_id_generator,
comment_kind,
attr_style,
data,
self.prev_token.span,
))
} else {
None
}
} else {
None
};
if let Some(attr) = attr {
let end_pos: u32 = self.num_bump_calls.try_into().unwrap();
let range = start_pos..end_pos;
if let Capturing::Yes = self.capture_state.capturing {
self.capture_state.inner_attr_ranges.insert(attr.id, (range, vec![]));
}
attrs.push(attr);
} else {
break;
}
}
Ok(attrs)
}
pub(crate) fn parse_unsuffixed_meta_item_lit(&mut self) -> PResult<'a, ast::MetaItemLit> {
let lit = self.parse_meta_item_lit()?;
debug!("checking if {:?} is unsuffixed", lit);
if !lit.kind.is_unsuffixed() {
self.sess.emit_err(SuffixedLiteralInAttribute { span: lit.span });
}
Ok(lit)
}
pub fn parse_cfg_attr(&mut self) -> PResult<'a, (ast::MetaItem, Vec<(ast::AttrItem, Span)>)> {
let cfg_predicate = self.parse_meta_item()?;
self.expect(&token::Comma)?;
let mut expanded_attrs = Vec::with_capacity(1);
while self.token.kind != token::Eof {
let lo = self.token.span;
let item = self.parse_attr_item(true)?;
expanded_attrs.push((item, lo.to(self.prev_token.span)));
if !self.eat(&token::Comma) {
break;
}
}
Ok((cfg_predicate, expanded_attrs))
}
pub(crate) fn parse_meta_seq_top(&mut self) -> PResult<'a, ThinVec<ast::NestedMetaItem>> {
let mut nmis = ThinVec::with_capacity(1);
while self.token.kind != token::Eof {
nmis.push(self.parse_meta_item_inner()?);
if !self.eat(&token::Comma) {
break;
}
}
Ok(nmis)
}
pub fn parse_meta_item(&mut self) -> PResult<'a, ast::MetaItem> {
let nt_meta = match &self.token.kind {
token::Interpolated(nt) => match &**nt {
token::NtMeta(e) => Some(e.clone()),
_ => None,
},
_ => None,
};
if let Some(item) = nt_meta {
return match item.meta(item.path.span) {
Some(meta) => {
self.bump();
Ok(meta)
}
None => self.unexpected(),
};
}
let lo = self.token.span;
let path = self.parse_path(PathStyle::Mod)?;
let kind = self.parse_meta_item_kind()?;
let span = lo.to(self.prev_token.span);
Ok(ast::MetaItem { path, kind, span })
}
pub(crate) fn parse_meta_item_kind(&mut self) -> PResult<'a, ast::MetaItemKind> {
Ok(if self.eat(&token::Eq) {
ast::MetaItemKind::NameValue(self.parse_unsuffixed_meta_item_lit()?)
} else if self.check(&token::OpenDelim(Delimiter::Parenthesis)) {
let (list, _) = self.parse_paren_comma_seq(|p| p.parse_meta_item_inner())?;
ast::MetaItemKind::List(list)
} else {
ast::MetaItemKind::Word
})
}
fn parse_meta_item_inner(&mut self) -> PResult<'a, ast::NestedMetaItem> {
match self.parse_unsuffixed_meta_item_lit() {
Ok(lit) => return Ok(ast::NestedMetaItem::Lit(lit)),
Err(err) => err.cancel(),
}
match self.parse_meta_item() {
Ok(mi) => return Ok(ast::NestedMetaItem::MetaItem(mi)),
Err(err) => err.cancel(),
}
Err(InvalidMetaItem { span: self.token.span, token: self.token.clone() }
.into_diagnostic(&self.sess.span_diagnostic))
}
}
pub fn is_complete(attrs: &[ast::Attribute]) -> bool {
attrs.iter().all(|attr| {
attr.is_doc_comment()
|| attr.ident().is_some_and(|ident| {
ident.name != sym::cfg_attr && rustc_feature::is_builtin_attr_name(ident.name)
})
})
}