use super::norm_util::{self, Symbols};
use super::precedence;
use super::{NormError, NormResult};
use crate::collections::{set, Multimap};
use crate::grammar::consts::*;
use crate::grammar::parse_tree::*;
use crate::grammar::repr as r;
use crate::util::Sep;
use string_cache::DefaultAtom as Atom;
#[cfg(test)]
mod test;
pub fn validate(grammar: &Grammar) -> NormResult<()> {
let match_token: Option<&MatchToken> = grammar
.items
.iter()
.filter_map(GrammarItem::as_match_token)
.next();
let extern_token: Option<&ExternToken> = grammar
.items
.iter()
.filter_map(GrammarItem::as_extern_token)
.next();
let validator = Validator {
grammar,
match_token,
extern_token,
};
validator.validate()
}
struct Validator<'grammar> {
grammar: &'grammar Grammar,
match_token: Option<&'grammar MatchToken>,
extern_token: Option<&'grammar ExternToken>,
}
impl<'grammar> Validator<'grammar> {
fn validate(&self) -> NormResult<()> {
let allowed_names = vec![
Atom::from(LALR),
Atom::from(TABLE_DRIVEN),
Atom::from(RECURSIVE_ASCENT),
Atom::from(TEST_ALL),
];
for annotation in &self.grammar.annotations {
if !allowed_names.contains(&annotation.id) {
return_err!(
annotation.id_span,
"unrecognized annotation `{}`",
annotation.id
);
}
}
for item in &self.grammar.items {
match *item {
GrammarItem::Use(..) => {}
GrammarItem::MatchToken(ref data) => {
if data.span != self.match_token.unwrap().span {
return_err!(data.span, "multiple match definitions are not permitted");
}
if let Some(d) = self.extern_token {
if d.enum_token.is_some() {
return_err!(
d.span,
"extern (with custom tokens) and match definitions are mutually exclusive");
}
}
for (contents_idx, match_contents) in data.contents.iter().enumerate() {
for (item_idx, item) in match_contents.items.iter().enumerate() {
if item.is_catch_all()
&& (contents_idx != &data.contents.len() - 1
|| item_idx != &match_contents.items.len() - 1)
{
return_err!(item.span(), "Catch all must be final item");
}
}
}
}
GrammarItem::ExternToken(ref data) => {
if data.span != self.extern_token.unwrap().span {
return_err!(data.span, "multiple extern definitions are not permitted");
}
if let Some(d) = self.match_token {
if data.enum_token.is_some() {
return_err!(
d.span,
"match and extern (with custom tokens) definitions are mutually exclusive");
}
}
let allowed_names = vec![Atom::from(LOCATION), Atom::from(ERROR)];
let mut new_names = set();
for associated_type in &data.associated_types {
if !allowed_names.contains(&associated_type.type_name) {
return_err!(
associated_type.type_span,
"associated type `{}` not recognized, \
try one of the following: {}",
associated_type.type_name,
Sep(", ", &allowed_names)
);
} else if !new_names.insert(associated_type.type_name.clone()) {
return_err!(
associated_type.type_span,
"associated type `{}` already specified",
associated_type.type_name
);
}
}
}
GrammarItem::Nonterminal(ref data) => {
if data.visibility.is_pub() && !data.args.is_empty() {
return_err!(data.span, "macros cannot be marked public");
}
let inline_annotation = Atom::from(INLINE);
let cfg_annotation = Atom::from(CFG);
let known_annotations = [inline_annotation.clone(), cfg_annotation.clone()];
let mut found_annotations = set();
for annotation in &data.annotations {
if !known_annotations.contains(&annotation.id) {
return_err!(
annotation.id_span,
"unrecognized annotation `{}`",
annotation.id
);
} else if !found_annotations.insert(annotation.id.clone()) {
return_err!(
annotation.id_span,
"duplicate annotation `{}`",
annotation.id
);
} else if annotation.id == inline_annotation && data.visibility.is_pub() {
return_err!(
annotation.id_span,
"public items cannot be marked #[inline]"
);
} else if annotation.id == cfg_annotation {
if data.visibility.is_pub() {
match annotation.arg {
Some((ref name, _)) if name == "feature" => (),
_ => return_err!(
annotation.id_span,
r#"`cfg` annotations must have a `feature = "my_feature" argument"#
),
}
} else {
return_err!(
annotation.id_span,
"private items cannot be marked #[cfg]"
);
}
}
}
self.validate_precedence(&data.alternatives)?;
for alternative in &data.alternatives {
self.validate_alternative(alternative)?;
}
}
GrammarItem::InternToken(..) => {}
}
}
Ok(())
}
fn validate_precedence(&self, alternatives: &Vec<Alternative>) -> NormResult<()> {
let with_precedence = alternatives.iter().any(|alt| {
alt.annotations.iter().any(|ann| {
ann.id == Atom::from(precedence::PREC_ANNOT)
|| ann.id == Atom::from(precedence::ASSOC_ANNOT)
})
});
if alternatives.is_empty() || !with_precedence {
return Ok(());
}
let mut min_lvl = u32::MAX;
let mut min_prec_ann: Option<&Annotation> = None;
alternatives.iter().try_for_each(|alt| {
let ann_prec_opt = alt.annotations.iter().find(|ann| ann.id == Atom::from(precedence::PREC_ANNOT));
let ann_assoc_opt = alt.annotations.iter().find(|ann| ann.id == Atom::from(precedence::ASSOC_ANNOT));
if let Some(ann_prec) = ann_prec_opt {
match &ann_prec.arg {
Some((name, value)) if *name == Atom::from(precedence::LVL_ARG) => {
if let Ok(lvl) = value.parse::<u32>() {
if lvl < min_lvl {
min_lvl = lvl;
min_prec_ann = ann_assoc_opt.clone();
}
else if lvl == min_lvl && min_prec_ann.is_none() && ann_assoc_opt.is_some() {
min_prec_ann = ann_assoc_opt.clone();
}
}
else {
return_err!(ann_prec.id_span, "could not parse the precedence level `{}`, expected integer", value);
}
}
Some((name, _)) => return_err!(ann_prec.id_span, "invalid argument `{}` for precedence annotation, expected `{}`", name, precedence::LVL_ARG),
None => return_err!(ann_prec.id_span, "missing argument for precedence annotation, expected `{}`", precedence::LVL_ARG),
}
}
else {
return_err!(alt.span, "missing precedence annotation");
}
if let Some(ann_assoc) = ann_assoc_opt {
match &ann_assoc.arg {
Some((name, value)) if *name == Atom::from(precedence::SIDE_ARG) => {
if value.parse::<precedence::Assoc>().is_err() {
return_err!(ann_assoc.id_span, "could not parse the associativity `{}`, expected `left`, `right` or `none`", value);
}
}
Some((name, _)) => return_err!(ann_assoc.id_span, "invalid argument `{}` for associativity annotation, expected `{}`", name, precedence::SIDE_ARG),
None => return_err!(ann_assoc.id_span, "missing argument for associativity annotation, expected `{}`", precedence::SIDE_ARG),
}
}
Ok(())
})?;
if let Some(ann) = min_prec_ann {
return_err!(
ann.id_span,
"cannot set associativity on the first precedence level {}",
min_lvl
);
}
Ok(())
}
fn validate_alternative(&self, alternative: &Alternative) -> NormResult<()> {
self.validate_expr(&alternative.expr)?;
let allowed_names = vec![
Atom::from(precedence::PREC_ANNOT),
Atom::from(precedence::ASSOC_ANNOT),
];
for annotation in &alternative.annotations {
if !allowed_names.contains(&annotation.id) {
return_err!(
annotation.id_span,
"unrecognized annotation `{}`",
annotation.id
);
}
}
match norm_util::analyze_expr(&alternative.expr) {
Symbols::Named(syms) => {
if alternative.action.is_none() {
let sym = syms.iter().map(|&(_, _, sym)| sym).next().unwrap();
return_err!(
sym.span,
"named symbols (like `{}`) require a custom action",
sym
);
}
}
Symbols::Anon(_) => {
let empty_string = "".to_string();
let action = {
match alternative.action {
Some(ActionKind::User(ref action)) => action,
Some(ActionKind::Fallible(ref action)) => action,
_ => &empty_string,
}
};
if norm_util::check_between_braces(action).is_in_curly_brackets() {
return_err!(
alternative.span,
"Using `<>` between curly braces (e.g., `{{<>}}`) only works when your parsed values have been given names (e.g., `<x:Foo>`, not just `<Foo>`)");
}
}
}
Ok(())
}
fn validate_expr(&self, expr: &ExprSymbol) -> NormResult<()> {
for symbol in &expr.symbols {
self.validate_symbol(symbol)?;
}
let chosen: Vec<&Symbol> = expr
.symbols
.iter()
.filter(|sym| match sym.kind {
SymbolKind::Choose(_) => true,
_ => false,
})
.collect();
let named: Multimap<Atom, Vec<&Symbol>> = expr
.symbols
.iter()
.filter_map(|sym| match sym.kind {
SymbolKind::Name(ref nt, _) => Some((nt.name.clone(), sym)),
_ => None,
})
.collect();
if !chosen.is_empty() && !named.is_empty() {
return_err!(
chosen[0].span,
"anonymous symbols like this one cannot be combined with \
named symbols like `{}`",
named.into_iter().next().unwrap().1[0]
);
}
for (name, syms) in named.into_iter() {
if syms.len() > 1 {
return_err!(
syms[1].span,
"multiple symbols named `{}` are not permitted",
name
);
}
}
Ok(())
}
fn validate_symbol(&self, symbol: &Symbol) -> NormResult<()> {
match symbol.kind {
SymbolKind::Expr(ref expr) => {
self.validate_expr(expr)?;
}
SymbolKind::AmbiguousId(_) => { }
SymbolKind::Terminal(_) => { }
SymbolKind::Nonterminal(_) => { }
SymbolKind::Error => {
let mut algorithm = r::Algorithm::default();
read_algorithm(&self.grammar.annotations, &mut algorithm);
if algorithm.codegen == r::LrCodeGeneration::RecursiveAscent {
return_err!(
symbol.span,
"error recovery is not yet supported by recursive ascent parsers"
);
}
}
SymbolKind::Macro(ref msym) => {
debug_assert!(!msym.args.is_empty());
for arg in &msym.args {
self.validate_symbol(arg)?;
}
}
SymbolKind::Repeat(ref repeat) => {
self.validate_symbol(&repeat.symbol)?;
}
SymbolKind::Choose(ref sym) | SymbolKind::Name(_, ref sym) => {
self.validate_symbol(sym)?;
}
SymbolKind::Lookahead | SymbolKind::Lookbehind => {
if let Some(extern_token) = self.extern_token {
if extern_token.enum_token.is_some() {
let loc = Atom::from(LOCATION);
if self.extern_token.unwrap().associated_type(loc).is_none() {
return_err!(
symbol.span,
"lookahead/lookbehind require you to declare the type of \
a location; add a `type {} = ..` statement to the extern token \
block",
LOCATION
);
}
}
}
}
}
Ok(())
}
}