bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Attempt to try to resolve blocking concerns

Browse source
This commit is contained in:
Caio 2023-12-01 21:19:22 -03:00
parent 64d7e0d0b6
commit 0278505691
16 changed files with 715 additions and 281 deletions
Download patch file Download diff file Expand all files Collapse all files

126
compiler/rustc_expand/src/expand.rs
View file

@ -41,6 +41,7 @@ use std::path::PathBuf;
use std::rc::Rc;
use std::{iter, mem};
#[cfg(bootstrap)]
macro_rules! ast_fragments {
(
$($Kind:ident($AstTy:ty) {
@ -165,6 +166,131 @@ macro_rules! ast_fragments {
}
}
#[cfg(not(bootstrap))]
macro_rules! ast_fragments {
(
$($Kind:ident($AstTy:ty) {
$kind_name:expr;
$(one fn $mut_visit_ast:ident; fn $visit_ast:ident;)?
$(many fn $flat_map_ast_elt:ident; fn $visit_ast_elt:ident($($args:tt)*);)?
fn $make_ast:ident;
})*
) => {
/// A fragment of AST that can be produced by a single macro expansion.
/// Can also serve as an input and intermediate result for macro expansion operations.
pub enum AstFragment {
OptExpr(Option<P<ast::Expr>>),
MethodReceiverExpr(P<ast::Expr>),
$($Kind($AstTy),)*
}
/// "Discriminant" of an AST fragment.
#[derive(Copy, Clone, PartialEq, Eq)]
pub enum AstFragmentKind {
OptExpr,
MethodReceiverExpr,
$($Kind,)*
}
impl AstFragmentKind {
pub fn name(self) -> &'static str {
match self {
AstFragmentKind::OptExpr => "expression",
AstFragmentKind::MethodReceiverExpr => "expression",
$(AstFragmentKind::$Kind => $kind_name,)*
}
}
fn make_from<'a>(self, result: Box<dyn MacResult + 'a>) -> Option<AstFragment> {
match self {
AstFragmentKind::OptExpr =>
result.make_expr().map(Some).map(AstFragment::OptExpr),
AstFragmentKind::MethodReceiverExpr =>
result.make_expr().map(AstFragment::MethodReceiverExpr),
$(AstFragmentKind::$Kind => result.$make_ast().map(AstFragment::$Kind),)*
}
}
}
impl AstFragment {
pub fn add_placeholders(&mut self, placeholders: &[NodeId]) {
if placeholders.is_empty() {
return;
}
match self {
$($(AstFragment::$Kind(ast) => ast.extend(placeholders.iter().flat_map(|id| {
${ignore($flat_map_ast_elt)}
placeholder(AstFragmentKind::$Kind, *id, None).$make_ast()
})),)?)*
_ => panic!("unexpected AST fragment kind")
}
}
pub fn make_opt_expr(self) -> Option<P<ast::Expr>> {
match self {
AstFragment::OptExpr(expr) => expr,
_ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
}
}
pub fn make_method_receiver_expr(self) -> P<ast::Expr> {
match self {
AstFragment::MethodReceiverExpr(expr) => expr,
_ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
}
}
$(pub fn $make_ast(self) -> $AstTy {
match self {
AstFragment::$Kind(ast) => ast,
_ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
}
})*
fn make_ast<T: InvocationCollectorNode>(self) -> T::OutputTy {
T::fragment_to_output(self)
}
pub fn mut_visit_with<F: MutVisitor>(&mut self, vis: &mut F) {
match self {
AstFragment::OptExpr(opt_expr) => {
visit_clobber(opt_expr, |opt_expr| {
if let Some(expr) = opt_expr {
vis.filter_map_expr(expr)
} else {
None
}
});
}
AstFragment::MethodReceiverExpr(expr) => vis.visit_method_receiver_expr(expr),
$($(AstFragment::$Kind(ast) => vis.$mut_visit_ast(ast),)?)*
$($(AstFragment::$Kind(ast) =>
ast.flat_map_in_place(|ast| vis.$flat_map_ast_elt(ast)),)?)*
}
}
pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
match self {
AstFragment::OptExpr(Some(expr)) => visitor.visit_expr(expr),
AstFragment::OptExpr(None) => {}
AstFragment::MethodReceiverExpr(expr) => visitor.visit_method_receiver_expr(expr),
$($(AstFragment::$Kind(ast) => visitor.$visit_ast(ast),)?)*
$($(AstFragment::$Kind(ast) => for ast_elt in &ast[..] {
visitor.$visit_ast_elt(ast_elt, $($args)*);
})?)*
}
}
}
impl<'a> MacResult for crate::mbe::macro_rules::ParserAnyMacro<'a> {
$(fn $make_ast(self: Box<crate::mbe::macro_rules::ParserAnyMacro<'a>>)
-> Option<$AstTy> {
Some(self.make(AstFragmentKind::$Kind).$make_ast())
})*
}
}
}
ast_fragments! {
Expr(P<ast::Expr>) { "expression"; one fn visit_expr; fn visit_expr; fn make_expr; }
Pat(P<ast::Pat>) { "pattern"; one fn visit_pat; fn visit_pat; fn make_pat; }

32
compiler/rustc_expand/src/mbe/metavar_expr.rs
View file

@ -10,9 +10,8 @@ use rustc_span::Span;
/// A meta-variable expression, for expansions based on properties of meta-variables.
#[derive(Debug, Clone, PartialEq, Encodable, Decodable)]
pub(crate) enum MetaVarExpr {
/// The number of repetitions of an identifier, optionally limited to a number
/// of outer-most repetition depths. If the depth limit is `None` then the depth is unlimited.
Count(Ident, Option<usize>),
/// The number of repetitions of an identifier.
Count(Ident, usize),
/// Ignore a meta-variable for repetition without expansion.
Ignore(Ident),
@ -43,7 +42,10 @@ impl MetaVarExpr {
let mut iter = args.trees();
let rslt = match ident.as_str() {
"count" => parse_count(&mut iter, sess, ident.span)?,
"ignore" => MetaVarExpr::Ignore(parse_ident(&mut iter, sess, ident.span)?),
"ignore" => {
eat_dollar(&mut iter, sess, ident.span)?;
MetaVarExpr::Ignore(parse_ident(&mut iter, sess, ident.span)?)
}
"index" => MetaVarExpr::Index(parse_depth(&mut iter, sess, ident.span)?),
"length" => MetaVarExpr::Length(parse_depth(&mut iter, sess, ident.span)?),
_ => {
@ -92,6 +94,7 @@ fn parse_count<'sess>(
sess: &'sess ParseSess,
span: Span,
) -> PResult<'sess, MetaVarExpr> {
eat_dollar(iter, sess, span)?;
let ident = parse_ident(iter, sess, span)?;
let depth = if try_eat_comma(iter) {
if iter.look_ahead(0).is_none() {
@ -100,9 +103,9 @@ fn parse_count<'sess>(
"`count` followed by a comma must have an associated index indicating its depth",
));
}
Some(parse_depth(iter, sess, span)?)
parse_depth(iter, sess, span)?
} else {
None
0
};
Ok(MetaVarExpr::Count(ident, depth))
}
@ -166,3 +169,20 @@ fn try_eat_comma(iter: &mut RefTokenTreeCursor<'_>) -> bool {
}
false
}
/// Expects that the next item is a dollar sign.
fn eat_dollar<'sess>(
iter: &mut RefTokenTreeCursor<'_>,
sess: &'sess ParseSess,
span: Span,
) -> PResult<'sess, ()> {
if let Some(TokenTree::Token(token::Token { kind: token::Dollar, .. }, _)) = iter.look_ahead(0)
{
let _ = iter.next();
return Ok(());
}
Err(sess.span_diagnostic.struct_span_err(
span,
"meta-variables within meta-variable expressions must be referenced using a dollar sign",
))
}

65
compiler/rustc_expand/src/mbe/transcribe.rs
View file

@ -422,7 +422,7 @@ fn lockstep_iter_size(
/// declared inside a single repetition and the index `1` implies two nested repetitions.
fn count_repetitions<'a>(
cx: &ExtCtxt<'a>,
depth_opt: Option<usize>,
depth_user: usize,
mut matched: &NamedMatch,
repeats: &[(usize, usize)],
sp: &DelimSpan,
@ -431,37 +431,45 @@ fn count_repetitions<'a>(
// (or at the top-level of `matched` if no depth is given).
fn count<'a>(
cx: &ExtCtxt<'a>,
declared_lhs_depth: usize,
depth_opt: Option<usize>,
depth_curr: usize,
depth_max: usize,
matched: &NamedMatch,
sp: &DelimSpan,
) -> PResult<'a, usize> {
match matched {
MatchedTokenTree(_) | MatchedNonterminal(_) => {
if declared_lhs_depth == 0 {
return Err(cx.create_err(CountRepetitionMisplaced { span: sp.entire() }));
}
match depth_opt {
None => Ok(1),
Some(_) => Err(out_of_bounds_err(cx, declared_lhs_depth, sp.entire(), "count")),
}
}
MatchedTokenTree(_) | MatchedNonterminal(_) => Ok(1),
MatchedSeq(named_matches) => {
let new_declared_lhs_depth = declared_lhs_depth + 1;
match depth_opt {
None => named_matches
if depth_curr == depth_max {
Ok(named_matches.len())
} else {
named_matches
.iter()
.map(|elem| count(cx, new_declared_lhs_depth, None, elem, sp))
.sum(),
Some(0) => Ok(named_matches.len()),
Some(depth) => named_matches
.iter()
.map(|elem| count(cx, new_declared_lhs_depth, Some(depth - 1), elem, sp))
.sum(),
.map(|elem| count(cx, depth_curr + 1, depth_max, elem, sp))
.sum()
}
}
}
}
/// Maximum depth
fn depth(counter: usize, matched: &NamedMatch) -> usize {
match matched {
MatchedTokenTree(_) | MatchedNonterminal(_) => counter,
MatchedSeq(named_matches) => {
let rslt = counter + 1;
if let Some(elem) = named_matches.first() { depth(rslt, elem) } else { rslt }
}
}
}
let depth_max = depth(0, matched)
.checked_sub(1)
.and_then(|el| el.checked_sub(repeats.len()))
.unwrap_or_default();
if depth_user > depth_max {
return Err(out_of_bounds_err(cx, depth_max + 1, sp.entire(), "count"));
}
// `repeats` records all of the nested levels at which we are currently
// matching meta-variables. The meta-var-expr `count($x)` only counts
// matches that occur in this "subtree" of the `NamedMatch` where we
@ -473,7 +481,12 @@ fn count_repetitions<'a>(
matched = &ads[idx];
}
}
count(cx, 0, depth_opt, matched, sp)
if let MatchedTokenTree(_) | MatchedNonterminal(_) = matched {
return Err(cx.create_err(CountRepetitionMisplaced { span: sp.entire() }));
}
count(cx, depth_user, depth_max, matched, sp)
}
/// Returns a `NamedMatch` item declared on the LHS given an arbitrary [Ident]
@ -505,7 +518,7 @@ fn out_of_bounds_err<'a>(
)
} else {
format!(
"depth parameter on meta-variable expression `{ty}` \
"depth parameter of meta-variable expression `{ty}` \
must be less than {max}"
)
};
@ -527,9 +540,9 @@ fn transcribe_metavar_expr<'a>(
span
};
match *expr {
MetaVarExpr::Count(original_ident, depth_opt) => {
MetaVarExpr::Count(original_ident, depth) => {
let matched = matched_from_ident(cx, original_ident, interp)?;
let count = count_repetitions(cx, depth_opt, matched, repeats, sp)?;
let count = count_repetitions(cx, depth, matched, repeats, sp)?;
let tt = TokenTree::token_alone(
TokenKind::lit(token::Integer, sym::integer(count), None),
visited_span(),