//! `macro_rules` macros. It uses `TokenTree` (from `tt` package) as the
//! interface, although it contains some code to bridge `SyntaxNode`s and
//! `TokenTree`s as well!
+//!
+//! The tes for this functionality live in another crate:
+//! `hir_def::macro_expansion_tests::mbe`.
mod parser;
mod expander;
mod syntax_bridge;
mod tt_iter;
-mod subtree_source;
-
-#[cfg(test)]
-mod tests;
+mod to_parser_input;
#[cfg(test)]
mod benchmark;
use std::fmt;
-pub use tt::{Delimiter, DelimiterKind, Punct};
-
use crate::{
- parser::{parse_pattern, parse_template, MetaTemplate, Op},
+ parser::{MetaTemplate, Op},
tt_iter::TtIter,
};
-#[derive(Debug, PartialEq, Eq)]
+// FIXME: we probably should re-think `token_tree_to_syntax_node` interfaces
+pub use ::parser::TopEntryPoint;
+pub use tt::{Delimiter, DelimiterKind, Punct};
+
+pub use crate::{
+ syntax_bridge::{
+ parse_exprs_with_sep, parse_to_token_tree, syntax_node_to_token_tree,
+ syntax_node_to_token_tree_with_modifications, token_tree_to_syntax_node, SyntheticToken,
+ SyntheticTokenId,
+ },
+ token_map::TokenMap,
+};
+
+#[derive(Debug, PartialEq, Eq, Clone)]
pub enum ParseError {
- UnexpectedToken(String),
- Expected(String),
+ UnexpectedToken(Box<str>),
+ Expected(Box<str>),
InvalidRepeat,
RepetitionEmptyTokenTree,
}
+impl ParseError {
+ fn expected(e: &str) -> ParseError {
+ ParseError::Expected(e.into())
+ }
+
+ fn unexpected(e: &str) -> ParseError {
+ ParseError::UnexpectedToken(e.into())
+ }
+}
+
+impl fmt::Display for ParseError {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match self {
+ ParseError::UnexpectedToken(it) => f.write_str(it),
+ ParseError::Expected(it) => f.write_str(it),
+ ParseError::InvalidRepeat => f.write_str("invalid repeat"),
+ ParseError::RepetitionEmptyTokenTree => f.write_str("empty token tree in repetition"),
+ }
+ }
+}
+
#[derive(Debug, PartialEq, Eq, Clone)]
pub enum ExpandError {
+ BindingError(Box<Box<str>>),
+ LeftoverTokens,
+ ConversionError,
+ LimitExceeded,
NoMatchingRule,
UnexpectedToken,
- BindingError(String),
- ConversionError,
- ProcMacroError(tt::ExpansionError),
- UnresolvedProcMacro,
- Other(String),
}
-impl From<tt::ExpansionError> for ExpandError {
- fn from(it: tt::ExpansionError) -> Self {
- ExpandError::ProcMacroError(it)
+impl ExpandError {
+ fn binding_error(e: impl Into<Box<str>>) -> ExpandError {
+ ExpandError::BindingError(Box::new(e.into()))
}
}
ExpandError::UnexpectedToken => f.write_str("unexpected token in input"),
ExpandError::BindingError(e) => f.write_str(e),
ExpandError::ConversionError => f.write_str("could not convert tokens"),
- ExpandError::ProcMacroError(e) => e.fmt(f),
- ExpandError::UnresolvedProcMacro => f.write_str("unresolved proc macro"),
- ExpandError::Other(e) => f.write_str(e),
+ ExpandError::LimitExceeded => f.write_str("Expand exceed limit"),
+ ExpandError::LeftoverTokens => f.write_str("leftover tokens"),
}
}
}
-pub use crate::{
- syntax_bridge::{
- ast_to_token_tree, parse_exprs_with_sep, parse_to_token_tree, syntax_node_to_token_tree,
- token_tree_to_syntax_node,
- },
- token_map::TokenMap,
-};
-
/// This struct contains AST for a single `macro_rules` definition. What might
/// be very confusing is that AST has almost exactly the same shape as
/// `tt::TokenTree`, but there's a crucial difference: in macro rules, `$ident`
/// and `$()*` have special meaning (see `Var` and `Repeat` data structures)
#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct MacroRules {
- rules: Vec<Rule>,
- /// Highest id of the token we have in TokenMap
- shift: Shift,
-}
-
-/// For Macro 2.0
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct MacroDef {
+pub struct DeclarativeMacro {
rules: Vec<Rule>,
/// Highest id of the token we have in TokenMap
shift: Shift,
rhs: MetaTemplate,
}
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-struct Shift(u32);
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct Shift(u32);
impl Shift {
- fn new(tt: &tt::Subtree) -> Shift {
+ pub fn new(tt: &tt::Subtree) -> Shift {
// Note that TokenId is started from zero,
// We have to add 1 to prevent duplication.
let value = max_id(tt).map_or(0, |it| it + 1);
// Find the max token id inside a subtree
fn max_id(subtree: &tt::Subtree) -> Option<u32> {
- subtree
- .token_trees
- .iter()
- .filter_map(|tt| match tt {
- tt::TokenTree::Subtree(subtree) => {
- let tree_id = max_id(subtree);
- match subtree.delimiter {
- Some(it) if it.id != tt::TokenId::unspecified() => {
- Some(tree_id.map_or(it.id.0, |t| t.max(it.id.0)))
- }
- _ => tree_id,
+ let filter = |tt: &_| match tt {
+ tt::TokenTree::Subtree(subtree) => {
+ let tree_id = max_id(subtree);
+ match subtree.delimiter {
+ Some(it) if it.id != tt::TokenId::unspecified() => {
+ Some(tree_id.map_or(it.id.0, |t| t.max(it.id.0)))
}
+ _ => tree_id,
}
- tt::TokenTree::Leaf(tt::Leaf::Ident(ident))
- if ident.id != tt::TokenId::unspecified() =>
- {
- Some(ident.id.0)
- }
- _ => None,
- })
- .max()
+ }
+ tt::TokenTree::Leaf(leaf) => {
+ let &(tt::Leaf::Ident(tt::Ident { id, .. })
+ | tt::Leaf::Punct(tt::Punct { id, .. })
+ | tt::Leaf::Literal(tt::Literal { id, .. })) = leaf;
+
+ (id != tt::TokenId::unspecified()).then(|| id.0)
+ }
+ };
+ subtree.token_trees.iter().filter_map(filter).max()
}
}
/// Shift given TokenTree token id
- fn shift_all(self, tt: &mut tt::Subtree) {
+ pub fn shift_all(self, tt: &mut tt::Subtree) {
for t in &mut tt.token_trees {
match t {
- tt::TokenTree::Leaf(leaf) => match leaf {
- tt::Leaf::Ident(ident) => ident.id = self.shift(ident.id),
- tt::Leaf::Punct(punct) => punct.id = self.shift(punct.id),
- tt::Leaf::Literal(lit) => lit.id = self.shift(lit.id),
- },
+ tt::TokenTree::Leaf(
+ tt::Leaf::Ident(tt::Ident { id, .. })
+ | tt::Leaf::Punct(tt::Punct { id, .. })
+ | tt::Leaf::Literal(tt::Literal { id, .. }),
+ ) => *id = self.shift(*id),
tt::TokenTree::Subtree(tt) => {
if let Some(it) = tt.delimiter.as_mut() {
it.id = self.shift(it.id);
- };
+ }
self.shift_all(tt)
}
}
}
}
- fn shift(self, id: tt::TokenId) -> tt::TokenId {
+ pub fn shift(self, id: tt::TokenId) -> tt::TokenId {
if id == tt::TokenId::unspecified() {
- return id;
+ id
+ } else {
+ tt::TokenId(id.0 + self.0)
}
- tt::TokenId(id.0 + self.0)
}
- fn unshift(self, id: tt::TokenId) -> Option<tt::TokenId> {
+ pub fn unshift(self, id: tt::TokenId) -> Option<tt::TokenId> {
id.0.checked_sub(self.0).map(tt::TokenId)
}
}
Call,
}
-impl MacroRules {
- pub fn parse(tt: &tt::Subtree) -> Result<MacroRules, ParseError> {
+impl DeclarativeMacro {
+ /// The old, `macro_rules! m {}` flavor.
+ pub fn parse_macro_rules(tt: &tt::Subtree) -> Result<DeclarativeMacro, ParseError> {
// Note: this parsing can be implemented using mbe machinery itself, by
// matching against `$($lhs:tt => $rhs:tt);*` pattern, but implementing
// manually seems easier.
rules.push(rule);
if let Err(()) = src.expect_char(';') {
if src.len() > 0 {
- return Err(ParseError::Expected("expected `;`".to_string()));
+ return Err(ParseError::expected("expected `;`"));
}
break;
}
}
- for rule in &rules {
- validate(&rule.lhs)?;
+ for Rule { lhs, .. } in &rules {
+ validate(lhs)?;
}
- Ok(MacroRules { rules, shift: Shift::new(tt) })
- }
-
- pub fn expand(&self, tt: &tt::Subtree) -> ExpandResult<tt::Subtree> {
- // apply shift
- let mut tt = tt.clone();
- self.shift.shift_all(&mut tt);
- expander::expand_rules(&self.rules, &tt)
- }
-
- pub fn map_id_down(&self, id: tt::TokenId) -> tt::TokenId {
- self.shift.shift(id)
- }
-
- pub fn map_id_up(&self, id: tt::TokenId) -> (tt::TokenId, Origin) {
- match self.shift.unshift(id) {
- Some(id) => (id, Origin::Call),
- None => (id, Origin::Def),
- }
+ Ok(DeclarativeMacro { rules, shift: Shift::new(tt) })
}
-}
-impl MacroDef {
- pub fn parse(tt: &tt::Subtree) -> Result<MacroDef, ParseError> {
+ /// The new, unstable `macro m {}` flavor.
+ pub fn parse_macro2(tt: &tt::Subtree) -> Result<DeclarativeMacro, ParseError> {
let mut src = TtIter::new(tt);
let mut rules = Vec::new();
rules.push(rule);
if let Err(()) = src.expect_any_char(&[';', ',']) {
if src.len() > 0 {
- return Err(ParseError::Expected(
- "expected `;` or `,` to delimit rules".to_string(),
- ));
+ return Err(ParseError::expected("expected `;` or `,` to delimit rules"));
}
break;
}
cov_mark::hit!(parse_macro_def_simple);
let rule = Rule::parse(&mut src, false)?;
if src.len() != 0 {
- return Err(ParseError::Expected("remain tokens in macro def".to_string()));
+ return Err(ParseError::expected("remaining tokens in macro def"));
}
rules.push(rule);
}
- for rule in &rules {
- validate(&rule.lhs)?;
+
+ for Rule { lhs, .. } in &rules {
+ validate(lhs)?;
}
- Ok(MacroDef { rules, shift: Shift::new(tt) })
+ Ok(DeclarativeMacro { rules, shift: Shift::new(tt) })
}
pub fn expand(&self, tt: &tt::Subtree) -> ExpandResult<tt::Subtree> {
None => (id, Origin::Def),
}
}
+
+ pub fn shift(&self) -> Shift {
+ self.shift
+ }
}
impl Rule {
fn parse(src: &mut TtIter, expect_arrow: bool) -> Result<Self, ParseError> {
- let lhs = src
- .expect_subtree()
- .map_err(|()| ParseError::Expected("expected subtree".to_string()))?;
+ let lhs = src.expect_subtree().map_err(|()| ParseError::expected("expected subtree"))?;
if expect_arrow {
- src.expect_char('=').map_err(|()| ParseError::Expected("expected `=`".to_string()))?;
- src.expect_char('>').map_err(|()| ParseError::Expected("expected `>`".to_string()))?;
+ src.expect_char('=').map_err(|()| ParseError::expected("expected `=`"))?;
+ src.expect_char('>').map_err(|()| ParseError::expected("expected `>`"))?;
}
- let rhs = src
- .expect_subtree()
- .map_err(|()| ParseError::Expected("expected subtree".to_string()))?;
+ let rhs = src.expect_subtree().map_err(|()| ParseError::expected("expected subtree"))?;
- let lhs = MetaTemplate(parse_pattern(lhs)?);
- let rhs = MetaTemplate(parse_template(rhs)?);
+ let lhs = MetaTemplate::parse_pattern(lhs)?;
+ let rhs = MetaTemplate::parse_template(rhs)?;
Ok(crate::Rule { lhs, rhs })
}
Op::Repeat { tokens: subtree, separator, .. } => {
// Checks that no repetition which could match an empty token
// https://github.com/rust-lang/rust/blob/a58b1ed44f5e06976de2bdc4d7dc81c36a96934f/src/librustc_expand/mbe/macro_rules.rs#L558
-
- if separator.is_none()
- && subtree.iter().all(|child_op| {
- match child_op {
- Op::Var { kind, .. } => {
- // vis is optional
- if kind.as_ref().map_or(false, |it| it == "vis") {
- return true;
- }
- }
- Op::Repeat { kind, .. } => {
- return matches!(
- kind,
- parser::RepeatKind::ZeroOrMore | parser::RepeatKind::ZeroOrOne
- )
- }
- Op::Leaf(_) => {}
- Op::Subtree { .. } => {}
- }
- false
- })
- {
+ let lsh_is_empty_seq = separator.is_none() && subtree.iter().all(|child_op| {
+ match child_op {
+ // vis is optional
+ Op::Var { kind: Some(kind), .. } => kind == "vis",
+ Op::Repeat {
+ kind: parser::RepeatKind::ZeroOrMore | parser::RepeatKind::ZeroOrOne,
+ ..
+ } => true,
+ _ => false,
+ }
+ });
+ if lsh_is_empty_seq {
return Err(ParseError::RepetitionEmptyTokenTree);
}
validate(subtree)?
Ok(())
}
+pub type ExpandResult<T> = ValueResult<T, ExpandError>;
+
#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct ExpandResult<T> {
+pub struct ValueResult<T, E> {
pub value: T,
- pub err: Option<ExpandError>,
+ pub err: Option<E>,
}
-impl<T> ExpandResult<T> {
+impl<T, E> ValueResult<T, E> {
pub fn ok(value: T) -> Self {
Self { value, err: None }
}
- pub fn only_err(err: ExpandError) -> Self
+ pub fn only_err(err: E) -> Self
where
T: Default,
{
Self { value: Default::default(), err: Some(err) }
}
- pub fn str_err(err: String) -> Self
- where
- T: Default,
- {
- Self::only_err(ExpandError::Other(err))
+ pub fn map<U>(self, f: impl FnOnce(T) -> U) -> ValueResult<U, E> {
+ ValueResult { value: f(self.value), err: self.err }
}
- pub fn map<U>(self, f: impl FnOnce(T) -> U) -> ExpandResult<U> {
- ExpandResult { value: f(self.value), err: self.err }
+ pub fn map_err<E2>(self, f: impl FnOnce(E) -> E2) -> ValueResult<T, E2> {
+ ValueResult { value: self.value, err: self.err.map(f) }
}
- pub fn result(self) -> Result<T, ExpandError> {
+ pub fn result(self) -> Result<T, E> {
self.err.map_or(Ok(self.value), Err)
}
}
-impl<T: Default> From<Result<T, ExpandError>> for ExpandResult<T> {
- fn from(result: Result<T, ExpandError>) -> Self {
+impl<T: Default, E> From<Result<T, E>> for ValueResult<T, E> {
+ fn from(result: Result<T, E>) -> Self {
result.map_or_else(Self::only_err, Self::ok)
}
}
projects / rust.git / blobdiff