Move some methods to `diagnostics.rs` away from `parser.rs`

Move a bunch of error recovery methods to `diagnostics.rs` away from
`parser.rs`.
This commit is contained in:
Esteban Küber 2019-05-23 12:55:26 -07:00
parent 976541884f
commit d1364d5284
2 changed files with 462 additions and 413 deletions

View File

@ -1,19 +1,104 @@
use crate::ast;
use crate::ast::{
BlockCheckMode, Expr, ExprKind, Item, ItemKind, Pat, PatKind, QSelf, Ty, TyKind, VariantData,
BlockCheckMode, BinOpKind, Expr, ExprKind, Item, ItemKind, Pat, PatKind, PathSegment, QSelf,
Ty, TyKind, VariantData,
};
use crate::parse::parser::{BlockMode, PathStyle, SemiColonMode, TokenType};
use crate::parse::{SeqSep, token, PResult, Parser};
use crate::parse::parser::{BlockMode, PathStyle, SemiColonMode, TokenType, TokenExpectType};
use crate::parse::token;
use crate::parse::PResult;
use crate::parse::Parser;
use crate::print::pprust;
use crate::ptr::P;
use crate::source_map::Spanned;
use crate::symbol::kw;
use crate::ThinVec;
use errors::{Applicability, DiagnosticBuilder};
use log::debug;
use syntax_pos::{Span, DUMMY_SP};
use crate::tokenstream::TokenTree;
use crate::util::parser::AssocOp;
use errors::{Applicability, DiagnosticBuilder, DiagnosticId, FatalError};
use syntax_pos::{Span, DUMMY_SP, MultiSpan};
use log::{debug, trace};
use std::slice;
pub enum Error {
FileNotFoundForModule {
mod_name: String,
default_path: String,
secondary_path: String,
dir_path: String,
},
DuplicatePaths {
mod_name: String,
default_path: String,
secondary_path: String,
},
UselessDocComment,
InclusiveRangeWithNoEnd,
}
impl Error {
fn span_err<S: Into<MultiSpan>>(
self,
sp: S,
handler: &errors::Handler,
) -> DiagnosticBuilder<'_> {
match self {
Error::FileNotFoundForModule {
ref mod_name,
ref default_path,
ref secondary_path,
ref dir_path,
} => {
let mut err = struct_span_err!(
handler,
sp,
E0583,
"file not found for module `{}`",
mod_name,
);
err.help(&format!(
"name the file either {} or {} inside the directory \"{}\"",
default_path,
secondary_path,
dir_path,
));
err
}
Error::DuplicatePaths { ref mod_name, ref default_path, ref secondary_path } => {
let mut err = struct_span_err!(
handler,
sp,
E0584,
"file for module `{}` found at both {} and {}",
mod_name,
default_path,
secondary_path,
);
err.help("delete or rename one of them to remove the ambiguity");
err
}
Error::UselessDocComment => {
let mut err = struct_span_err!(
handler,
sp,
E0585,
"found a documentation comment that doesn't document anything",
);
err.help("doc comments must come before what they document, maybe a comment was \
intended with `//`?");
err
}
Error::InclusiveRangeWithNoEnd => {
let mut err = struct_span_err!(
handler,
sp,
E0586,
"inclusive range with no end",
);
err.help("inclusive ranges must be bounded at the end (`..=b` or `a..=b`)");
err
}
}
}
}
pub trait RecoverQPath: Sized + 'static {
const PATH_STYLE: PathStyle = PathStyle::Expr;
@ -63,6 +148,253 @@ impl RecoverQPath for Expr {
}
impl<'a> Parser<'a> {
pub fn look_ahead<R, F>(&self, dist: usize, f: F) -> R where
F: FnOnce(&token::Token) -> R,
{
if dist == 0 {
return f(&self.token)
}
f(&match self.token_cursor.frame.tree_cursor.look_ahead(dist - 1) {
Some(tree) => match tree {
TokenTree::Token(_, tok) => tok,
TokenTree::Delimited(_, delim, _) => token::OpenDelim(delim),
},
None => token::CloseDelim(self.token_cursor.frame.delim),
})
}
crate fn look_ahead_span(&self, dist: usize) -> Span {
if dist == 0 {
return self.span
}
match self.token_cursor.frame.tree_cursor.look_ahead(dist - 1) {
Some(TokenTree::Token(span, _)) => span,
Some(TokenTree::Delimited(span, ..)) => span.entire(),
None => self.look_ahead_span(dist - 1),
}
}
pub fn fatal(&self, m: &str) -> DiagnosticBuilder<'a> {
self.sess.span_diagnostic.struct_span_fatal(self.span, m)
}
pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
self.sess.span_diagnostic.struct_span_fatal(sp, m)
}
pub fn span_fatal_err<S: Into<MultiSpan>>(&self, sp: S, err: Error) -> DiagnosticBuilder<'a> {
err.span_err(sp, self.diagnostic())
}
pub fn bug(&self, m: &str) -> ! {
self.sess.span_diagnostic.span_bug(self.span, m)
}
pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) {
self.sess.span_diagnostic.span_err(sp, m)
}
crate fn struct_span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
self.sess.span_diagnostic.struct_span_err(sp, m)
}
crate fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> ! {
self.sess.span_diagnostic.span_bug(sp, m)
}
crate fn cancel(&self, err: &mut DiagnosticBuilder<'_>) {
self.sess.span_diagnostic.cancel(err)
}
crate fn diagnostic(&self) -> &'a errors::Handler {
&self.sess.span_diagnostic
}
crate fn expected_ident_found(&self) -> DiagnosticBuilder<'a> {
let mut err = self.struct_span_err(
self.span,
&format!("expected identifier, found {}", self.this_token_descr()),
);
if let token::Ident(ident, false) = &self.token {
if ident.is_raw_guess() {
err.span_suggestion(
self.span,
"you can escape reserved keywords to use them as identifiers",
format!("r#{}", ident),
Applicability::MaybeIncorrect,
);
}
}
if let Some(token_descr) = self.token_descr() {
err.span_label(self.span, format!("expected identifier, found {}", token_descr));
} else {
err.span_label(self.span, "expected identifier");
if self.token == token::Comma && self.look_ahead(1, |t| t.is_ident()) {
err.span_suggestion(
self.span,
"remove this comma",
String::new(),
Applicability::MachineApplicable,
);
}
}
err
}
/// Eats and discards tokens until one of `kets` is encountered. Respects token trees,
/// passes through any errors encountered. Used for error recovery.
crate fn eat_to_tokens(&mut self, kets: &[&token::Token]) {
let handler = self.diagnostic();
if let Err(ref mut err) = self.parse_seq_to_before_tokens(
kets,
SeqSep::none(),
TokenExpectType::Expect,
|p| Ok(p.parse_token_tree()),
) {
handler.cancel(err);
}
}
/// This function checks if there are trailing angle brackets and produces
/// a diagnostic to suggest removing them.
///
/// ```ignore (diagnostic)
/// let _ = vec![1, 2, 3].into_iter().collect::<Vec<usize>>>>();
/// ^^ help: remove extra angle brackets
/// ```
crate fn check_trailing_angle_brackets(&mut self, segment: &PathSegment, end: token::Token) {
// This function is intended to be invoked after parsing a path segment where there are two
// cases:
//
// 1. A specific token is expected after the path segment.
// eg. `x.foo(`, `x.foo::<u32>(` (parenthesis - method call),
// `Foo::`, or `Foo::<Bar>::` (mod sep - continued path).
// 2. No specific token is expected after the path segment.
// eg. `x.foo` (field access)
//
// This function is called after parsing `.foo` and before parsing the token `end` (if
// present). This includes any angle bracket arguments, such as `.foo::<u32>` or
// `Foo::<Bar>`.
// We only care about trailing angle brackets if we previously parsed angle bracket
// arguments. This helps stop us incorrectly suggesting that extra angle brackets be
// removed in this case:
//
// `x.foo >> (3)` (where `x.foo` is a `u32` for example)
//
// This case is particularly tricky as we won't notice it just looking at the tokens -
// it will appear the same (in terms of upcoming tokens) as below (since the `::<u32>` will
// have already been parsed):
//
// `x.foo::<u32>>>(3)`
let parsed_angle_bracket_args = segment.args
.as_ref()
.map(|args| args.is_angle_bracketed())
.unwrap_or(false);
debug!(
"check_trailing_angle_brackets: parsed_angle_bracket_args={:?}",
parsed_angle_bracket_args,
);
if !parsed_angle_bracket_args {
return;
}
// Keep the span at the start so we can highlight the sequence of `>` characters to be
// removed.
let lo = self.span;
// We need to look-ahead to see if we have `>` characters without moving the cursor forward
// (since we might have the field access case and the characters we're eating are
// actual operators and not trailing characters - ie `x.foo >> 3`).
let mut position = 0;
// We can encounter `>` or `>>` tokens in any order, so we need to keep track of how
// many of each (so we can correctly pluralize our error messages) and continue to
// advance.
let mut number_of_shr = 0;
let mut number_of_gt = 0;
while self.look_ahead(position, |t| {
trace!("check_trailing_angle_brackets: t={:?}", t);
if *t == token::BinOp(token::BinOpToken::Shr) {
number_of_shr += 1;
true
} else if *t == token::Gt {
number_of_gt += 1;
true
} else {
false
}
}) {
position += 1;
}
// If we didn't find any trailing `>` characters, then we have nothing to error about.
debug!(
"check_trailing_angle_brackets: number_of_gt={:?} number_of_shr={:?}",
number_of_gt, number_of_shr,
);
if number_of_gt < 1 && number_of_shr < 1 {
return;
}
// Finally, double check that we have our end token as otherwise this is the
// second case.
if self.look_ahead(position, |t| {
trace!("check_trailing_angle_brackets: t={:?}", t);
*t == end
}) {
// Eat from where we started until the end token so that parsing can continue
// as if we didn't have those extra angle brackets.
self.eat_to_tokens(&[&end]);
let span = lo.until(self.span);
let plural = number_of_gt > 1 || number_of_shr >= 1;
self.diagnostic()
.struct_span_err(
span,
&format!("unmatched angle bracket{}", if plural { "s" } else { "" }),
)
.span_suggestion(
span,
&format!("remove extra angle bracket{}", if plural { "s" } else { "" }),
String::new(),
Applicability::MachineApplicable,
)
.emit();
}
}
/// Produce an error if comparison operators are chained (RFC #558).
/// We only need to check lhs, not rhs, because all comparison ops
/// have same precedence and are left-associative
crate fn check_no_chained_comparison(&self, lhs: &Expr, outer_op: &AssocOp) {
debug_assert!(outer_op.is_comparison(),
"check_no_chained_comparison: {:?} is not comparison",
outer_op);
match lhs.node {
ExprKind::Binary(op, _, _) if op.node.is_comparison() => {
// respan to include both operators
let op_span = op.span.to(self.span);
let mut err = self.diagnostic().struct_span_err(op_span,
"chained comparison operators require parentheses");
if op.node == BinOpKind::Lt &&
*outer_op == AssocOp::Less || // Include `<` to provide this recommendation
*outer_op == AssocOp::Greater // even in a case like the following:
{ // Foo<Bar<Baz<Qux, ()>>>
err.help(
"use `::<...>` instead of `<...>` if you meant to specify type arguments");
err.help("or use `(...)` if you meant to specify fn arguments");
}
err.emit();
}
_ => {}
}
}
crate fn maybe_report_ambiguous_plus(
&mut self,
allow_plus: bool,
@ -594,6 +926,96 @@ impl<'a> Parser<'a> {
}
}
crate fn check_for_for_in_in_typo(&mut self, in_span: Span) {
if self.eat_keyword(kw::In) {
// a common typo: `for _ in in bar {}`
let mut err = self.sess.span_diagnostic.struct_span_err(
self.prev_span,
"expected iterable, found keyword `in`",
);
err.span_suggestion_short(
in_span.until(self.prev_span),
"remove the duplicated `in`",
String::new(),
Applicability::MachineApplicable,
);
err.note("if you meant to use emplacement syntax, it is obsolete (for now, anyway)");
err.note("for more information on the status of emplacement syntax, see <\
https://github.com/rust-lang/rust/issues/27779#issuecomment-378416911>");
err.emit();
}
}
crate fn expected_semi_or_open_brace(&mut self) -> PResult<'a, ast::TraitItem> {
let token_str = self.this_token_descr();
let mut err = self.fatal(&format!("expected `;` or `{{`, found {}", token_str));
err.span_label(self.span, "expected `;` or `{`");
Err(err)
}
crate fn eat_incorrect_doc_comment(&mut self, applied_to: &str) {
if let token::DocComment(_) = self.token {
let mut err = self.diagnostic().struct_span_err(
self.span,
&format!("documentation comments cannot be applied to {}", applied_to),
);
err.span_label(self.span, "doc comments are not allowed here");
err.emit();
self.bump();
} else if self.token == token::Pound && self.look_ahead(1, |t| {
*t == token::OpenDelim(token::Bracket)
}) {
let lo = self.span;
// Skip every token until next possible arg.
while self.token != token::CloseDelim(token::Bracket) {
self.bump();
}
let sp = lo.to(self.span);
self.bump();
let mut err = self.diagnostic().struct_span_err(
sp,
&format!("attributes cannot be applied to {}", applied_to),
);
err.span_label(sp, "attributes are not allowed here");
err.emit();
}
}
crate fn argument_without_type(
&mut self,
err: &mut DiagnosticBuilder<'_>,
pat: P<ast::Pat>,
require_name: bool,
is_trait_item: bool,
) {
// If we find a pattern followed by an identifier, it could be an (incorrect)
// C-style parameter declaration.
if self.check_ident() && self.look_ahead(1, |t| {
*t == token::Comma || *t == token::CloseDelim(token::Paren)
}) {
let ident = self.parse_ident().unwrap();
let span = pat.span.with_hi(ident.span.hi());
err.span_suggestion(
span,
"declare the type after the parameter binding",
String::from("<identifier>: <type>"),
Applicability::HasPlaceholders,
);
} else if require_name && is_trait_item {
if let PatKind::Ident(_, ident, _) = pat.node {
err.span_suggestion(
pat.span,
"explicitly ignore parameter",
format!("_: {}", ident),
Applicability::MachineApplicable,
);
}
err.note("anonymous parameters are removed in the 2018 edition (see RFC 1685)");
}
}
crate fn recover_arg_parse(&mut self) -> PResult<'a, (P<ast::Pat>, P<ast::Ty>)> {
let pat = self.parse_pat(Some("argument name"))?;
self.expect(&token::Colon)?;

View File

@ -47,20 +47,17 @@ use crate::parse::PResult;
use crate::ThinVec;
use crate::tokenstream::{self, DelimSpan, TokenTree, TokenStream, TreeAndJoint};
use crate::symbol::{kw, sym, Symbol};
use crate::parse::diagnostics::Error;
use errors::{Applicability, DiagnosticBuilder, DiagnosticId, FatalError};
use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
use rustc_target::spec::abi::{self, Abi};
use syntax_pos::{
BytePos, DUMMY_SP, FileName, MultiSpan, Span,
hygiene::CompilerDesugaringKind,
};
use log::{debug, trace};
use syntax_pos::{Span, BytePos, DUMMY_SP, FileName, hygiene::CompilerDesugaringKind};
use log::debug;
use std::borrow::Cow;
use std::cmp;
use std::mem;
use std::path::{self, Path, PathBuf};
use std::slice;
#[derive(Debug)]
/// Whether the type alias or associated type is a concrete type or an existential type
@ -217,7 +214,7 @@ pub struct Parser<'a> {
/// into modules, and sub-parsers have new values for this name.
pub root_module_name: Option<String>,
crate expected_tokens: Vec<TokenType>,
token_cursor: TokenCursor,
crate token_cursor: TokenCursor,
desugar_doc_comments: bool,
/// Whether we should configure out of line modules as we parse.
pub cfg_mods: bool,
@ -232,7 +229,7 @@ pub struct Parser<'a> {
/// it gets removed from here. Every entry left at the end gets emitted as an independent
/// error.
crate unclosed_delims: Vec<UnmatchedBrace>,
last_unexpected_token_span: Option<Span>,
crate last_unexpected_token_span: Option<Span>,
/// If present, this `Parser` is not parsing Rust code but rather a macro call.
crate subparser_name: Option<&'static str>,
}
@ -245,19 +242,19 @@ impl<'a> Drop for Parser<'a> {
}
#[derive(Clone)]
struct TokenCursor {
frame: TokenCursorFrame,
stack: Vec<TokenCursorFrame>,
crate struct TokenCursor {
crate frame: TokenCursorFrame,
crate stack: Vec<TokenCursorFrame>,
}
#[derive(Clone)]
struct TokenCursorFrame {
delim: token::DelimToken,
span: DelimSpan,
open_delim: bool,
tree_cursor: tokenstream::Cursor,
close_delim: bool,
last_token: LastToken,
crate struct TokenCursorFrame {
crate delim: token::DelimToken,
crate span: DelimSpan,
crate open_delim: bool,
crate tree_cursor: tokenstream::Cursor,
crate close_delim: bool,
crate last_token: LastToken,
}
/// This is used in `TokenCursorFrame` above to track tokens that are consumed
@ -278,7 +275,7 @@ struct TokenCursorFrame {
/// You can find some more example usage of this in the `collect_tokens` method
/// on the parser.
#[derive(Clone)]
enum LastToken {
crate enum LastToken {
Collecting(Vec<TreeAndJoint>),
Was(Option<TreeAndJoint>),
}
@ -430,65 +427,6 @@ pub struct ModulePathSuccess {
warn: bool,
}
pub enum Error {
FileNotFoundForModule {
mod_name: String,
default_path: String,
secondary_path: String,
dir_path: String,
},
DuplicatePaths {
mod_name: String,
default_path: String,
secondary_path: String,
},
UselessDocComment,
InclusiveRangeWithNoEnd,
}
impl Error {
fn span_err<S: Into<MultiSpan>>(self,
sp: S,
handler: &errors::Handler) -> DiagnosticBuilder<'_> {
match self {
Error::FileNotFoundForModule { ref mod_name,
ref default_path,
ref secondary_path,
ref dir_path } => {
let mut err = struct_span_err!(handler, sp, E0583,
"file not found for module `{}`", mod_name);
err.help(&format!("name the file either {} or {} inside the directory \"{}\"",
default_path,
secondary_path,
dir_path));
err
}
Error::DuplicatePaths { ref mod_name, ref default_path, ref secondary_path } => {
let mut err = struct_span_err!(handler, sp, E0584,
"file for module `{}` found at both {} and {}",
mod_name,
default_path,
secondary_path);
err.help("delete or rename one of them to remove the ambiguity");
err
}
Error::UselessDocComment => {
let mut err = struct_span_err!(handler, sp, E0585,
"found a documentation comment that doesn't document anything");
err.help("doc comments must come before what they document, maybe a comment was \
intended with `//`?");
err
}
Error::InclusiveRangeWithNoEnd => {
let mut err = struct_span_err!(handler, sp, E0586,
"inclusive range with no end");
err.help("inclusive ranges must be bounded at the end (`..=b` or `a..=b`)");
err
}
}
}
}
#[derive(Debug)]
enum LhsExpr {
NotYetParsed,
@ -529,7 +467,7 @@ fn dummy_arg(span: Span) -> Arg {
}
#[derive(Copy, Clone, Debug)]
enum TokenExpectType {
crate enum TokenExpectType {
Expect,
NoExpect,
}
@ -610,7 +548,7 @@ impl<'a> Parser<'a> {
pprust::token_to_string(&self.token)
}
fn token_descr(&self) -> Option<&'static str> {
crate fn token_descr(&self) -> Option<&'static str> {
Some(match &self.token {
t if t.is_special_ident() => "reserved identifier",
t if t.is_used_keyword() => "keyword",
@ -801,9 +739,10 @@ impl<'a> Parser<'a> {
}
/// Returns the span of expr, if it was not interpolated or the span of the interpolated token.
fn interpolated_or_expr_span(&self,
expr: PResult<'a, P<Expr>>)
-> PResult<'a, (Span, P<Expr>)> {
fn interpolated_or_expr_span(
&self,
expr: PResult<'a, P<Expr>>,
) -> PResult<'a, (Span, P<Expr>)> {
expr.map(|e| {
if self.prev_token_kind == PrevTokenKind::Interpolated {
(self.prev_span, e)
@ -813,36 +752,6 @@ impl<'a> Parser<'a> {
})
}
fn expected_ident_found(&self) -> DiagnosticBuilder<'a> {
let mut err = self.struct_span_err(self.span,
&format!("expected identifier, found {}",
self.this_token_descr()));
if let token::Ident(ident, false) = &self.token {
if ident.is_raw_guess() {
err.span_suggestion(
self.span,
"you can escape reserved keywords to use them as identifiers",
format!("r#{}", ident),
Applicability::MaybeIncorrect,
);
}
}
if let Some(token_descr) = self.token_descr() {
err.span_label(self.span, format!("expected identifier, found {}", token_descr));
} else {
err.span_label(self.span, "expected identifier");
if self.token == token::Comma && self.look_ahead(1, |t| t.is_ident()) {
err.span_suggestion(
self.span,
"remove this comma",
String::new(),
Applicability::MachineApplicable,
);
}
}
err
}
pub fn parse_ident(&mut self) -> PResult<'a, ast::Ident> {
self.parse_ident_common(true)
}
@ -925,7 +834,7 @@ impl<'a> Parser<'a> {
}
}
fn check_ident(&mut self) -> bool {
crate fn check_ident(&mut self) -> bool {
if self.token.is_ident() {
true
} else {
@ -1115,19 +1024,6 @@ impl<'a> Parser<'a> {
}
}
/// Eats and discards tokens until one of `kets` is encountered. Respects token trees,
/// passes through any errors encountered. Used for error recovery.
fn eat_to_tokens(&mut self, kets: &[&token::Token]) {
let handler = self.diagnostic();
if let Err(ref mut err) = self.parse_seq_to_before_tokens(kets,
SeqSep::none(),
TokenExpectType::Expect,
|p| Ok(p.parse_token_tree())) {
handler.cancel(err);
}
}
/// Parses a sequence, including the closing delimiter. The function
/// `f` must consume tokens until reaching the next separator or
/// closing bracket.
@ -1159,7 +1055,7 @@ impl<'a> Parser<'a> {
self.parse_seq_to_before_tokens(&[ket], sep, TokenExpectType::Expect, f)
}
fn parse_seq_to_before_tokens<T, F>(
crate fn parse_seq_to_before_tokens<T, F>(
&mut self,
kets: &[&token::Token],
sep: SeqSep,
@ -1292,63 +1188,6 @@ impl<'a> Parser<'a> {
self.expected_tokens.clear();
}
pub fn look_ahead<R, F>(&self, dist: usize, f: F) -> R where
F: FnOnce(&token::Token) -> R,
{
if dist == 0 {
return f(&self.token)
}
f(&match self.token_cursor.frame.tree_cursor.look_ahead(dist - 1) {
Some(tree) => match tree {
TokenTree::Token(_, tok) => tok,
TokenTree::Delimited(_, delim, _) => token::OpenDelim(delim),
},
None => token::CloseDelim(self.token_cursor.frame.delim),
})
}
crate fn look_ahead_span(&self, dist: usize) -> Span {
if dist == 0 {
return self.span
}
match self.token_cursor.frame.tree_cursor.look_ahead(dist - 1) {
Some(TokenTree::Token(span, _)) => span,
Some(TokenTree::Delimited(span, ..)) => span.entire(),
None => self.look_ahead_span(dist - 1),
}
}
pub fn fatal(&self, m: &str) -> DiagnosticBuilder<'a> {
self.sess.span_diagnostic.struct_span_fatal(self.span, m)
}
pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
self.sess.span_diagnostic.struct_span_fatal(sp, m)
}
fn span_fatal_err<S: Into<MultiSpan>>(&self, sp: S, err: Error) -> DiagnosticBuilder<'a> {
err.span_err(sp, self.diagnostic())
}
fn bug(&self, m: &str) -> ! {
self.sess.span_diagnostic.span_bug(self.span, m)
}
fn span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) {
self.sess.span_diagnostic.span_err(sp, m)
}
crate fn struct_span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
self.sess.span_diagnostic.struct_span_err(sp, m)
}
crate fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> ! {
self.sess.span_diagnostic.span_bug(sp, m)
}
fn cancel(&self, err: &mut DiagnosticBuilder<'_>) {
self.sess.span_diagnostic.cancel(err)
}
crate fn diagnostic(&self) -> &'a errors::Handler {
&self.sess.span_diagnostic
}
/// Is the current token one of the keywords that signals a bare function type?
fn token_is_bare_fn_keyword(&mut self) -> bool {
self.check_keyword(kw::Fn) ||
@ -1507,20 +1346,12 @@ impl<'a> Parser<'a> {
Some(body)
}
_ => {
let token_str = self.this_token_descr();
let mut err = self.fatal(&format!("expected `;` or `{{`, found {}",
token_str));
err.span_label(self.span, "expected `;` or `{`");
return Err(err);
return self.expected_semi_or_open_brace();
}
}
}
_ => {
let token_str = self.this_token_descr();
let mut err = self.fatal(&format!("expected `;` or `{{`, found {}",
token_str));
err.span_label(self.span, "expected `;` or `{`");
return Err(err);
return self.expected_semi_or_open_brace();
}
};
(ident, ast::TraitItemKind::Method(sig, body), generics)
@ -1776,34 +1607,6 @@ impl<'a> Parser<'a> {
/// Skips unexpected attributes and doc comments in this position and emits an appropriate
/// error.
fn eat_incorrect_doc_comment(&mut self, applied_to: &str) {
if let token::DocComment(_) = self.token {
let mut err = self.diagnostic().struct_span_err(
self.span,
&format!("documentation comments cannot be applied to {}", applied_to),
);
err.span_label(self.span, "doc comments are not allowed here");
err.emit();
self.bump();
} else if self.token == token::Pound && self.look_ahead(1, |t| {
*t == token::OpenDelim(token::Bracket)
}) {
let lo = self.span;
// Skip every token until next possible arg.
while self.token != token::CloseDelim(token::Bracket) {
self.bump();
}
let sp = lo.to(self.span);
self.bump();
let mut err = self.diagnostic().struct_span_err(
sp,
&format!("attributes cannot be applied to {}", applied_to),
);
err.span_label(sp, "attributes are not allowed here");
err.emit();
}
}
/// This version of parse arg doesn't necessarily require identifier names.
fn parse_arg_general(
&mut self,
@ -1858,30 +1661,7 @@ impl<'a> Parser<'a> {
// Recover from attempting to parse the argument as a type without pattern.
err.cancel();
mem::replace(self, parser_snapshot_before_ty);
let pat = self.parse_pat(Some("argument name"))?;
self.expect(&token::Colon)?;
let ty = self.parse_ty()?;
let mut err = self.diagnostic().struct_span_err_with_code(
pat.span,
"patterns aren't allowed in methods without bodies",
DiagnosticId::Error("E0642".into()),
);
err.span_suggestion_short(
pat.span,
"give this argument a name or use an underscore to ignore it",
"_".to_owned(),
Applicability::MachineApplicable,
);
err.emit();
// Pretend the pattern is `_`, to avoid duplicate errors from AST validation.
let pat = P(Pat {
node: PatKind::Wild,
span: pat.span,
id: ast::DUMMY_NODE_ID
});
(pat, ty)
self.recover_arg_parse()?
}
}
};
@ -1889,11 +1669,6 @@ impl<'a> Parser<'a> {
Ok(Arg { ty, pat, id: ast::DUMMY_NODE_ID, source: ast::ArgSource::Normal })
}
/// Parses a single function argument.
crate fn parse_arg(&mut self) -> PResult<'a, Arg> {
self.parse_arg_general(true, false, false)
}
/// Parses an argument in a lambda header (e.g., `|arg, arg|`).
fn parse_fn_block_arg(&mut self) -> PResult<'a, Arg> {
let pat = self.parse_pat(Some("argument name"))?;
@ -2858,116 +2633,6 @@ impl<'a> Parser<'a> {
})
}
/// This function checks if there are trailing angle brackets and produces
/// a diagnostic to suggest removing them.
///
/// ```ignore (diagnostic)
/// let _ = vec![1, 2, 3].into_iter().collect::<Vec<usize>>>>();
/// ^^ help: remove extra angle brackets
/// ```
fn check_trailing_angle_brackets(&mut self, segment: &PathSegment, end: token::Token) {
// This function is intended to be invoked after parsing a path segment where there are two
// cases:
//
// 1. A specific token is expected after the path segment.
// eg. `x.foo(`, `x.foo::<u32>(` (parenthesis - method call),
// `Foo::`, or `Foo::<Bar>::` (mod sep - continued path).
// 2. No specific token is expected after the path segment.
// eg. `x.foo` (field access)
//
// This function is called after parsing `.foo` and before parsing the token `end` (if
// present). This includes any angle bracket arguments, such as `.foo::<u32>` or
// `Foo::<Bar>`.
// We only care about trailing angle brackets if we previously parsed angle bracket
// arguments. This helps stop us incorrectly suggesting that extra angle brackets be
// removed in this case:
//
// `x.foo >> (3)` (where `x.foo` is a `u32` for example)
//
// This case is particularly tricky as we won't notice it just looking at the tokens -
// it will appear the same (in terms of upcoming tokens) as below (since the `::<u32>` will
// have already been parsed):
//
// `x.foo::<u32>>>(3)`
let parsed_angle_bracket_args = segment.args
.as_ref()
.map(|args| args.is_angle_bracketed())
.unwrap_or(false);
debug!(
"check_trailing_angle_brackets: parsed_angle_bracket_args={:?}",
parsed_angle_bracket_args,
);
if !parsed_angle_bracket_args {
return;
}
// Keep the span at the start so we can highlight the sequence of `>` characters to be
// removed.
let lo = self.span;
// We need to look-ahead to see if we have `>` characters without moving the cursor forward
// (since we might have the field access case and the characters we're eating are
// actual operators and not trailing characters - ie `x.foo >> 3`).
let mut position = 0;
// We can encounter `>` or `>>` tokens in any order, so we need to keep track of how
// many of each (so we can correctly pluralize our error messages) and continue to
// advance.
let mut number_of_shr = 0;
let mut number_of_gt = 0;
while self.look_ahead(position, |t| {
trace!("check_trailing_angle_brackets: t={:?}", t);
if *t == token::BinOp(token::BinOpToken::Shr) {
number_of_shr += 1;
true
} else if *t == token::Gt {
number_of_gt += 1;
true
} else {
false
}
}) {
position += 1;
}
// If we didn't find any trailing `>` characters, then we have nothing to error about.
debug!(
"check_trailing_angle_brackets: number_of_gt={:?} number_of_shr={:?}",
number_of_gt, number_of_shr,
);
if number_of_gt < 1 && number_of_shr < 1 {
return;
}
// Finally, double check that we have our end token as otherwise this is the
// second case.
if self.look_ahead(position, |t| {
trace!("check_trailing_angle_brackets: t={:?}", t);
*t == end
}) {
// Eat from where we started until the end token so that parsing can continue
// as if we didn't have those extra angle brackets.
self.eat_to_tokens(&[&end]);
let span = lo.until(self.span);
let plural = number_of_gt > 1 || number_of_shr >= 1;
self.diagnostic()
.struct_span_err(
span,
&format!("unmatched angle bracket{}", if plural { "s" } else { "" }),
)
.span_suggestion(
span,
&format!("remove extra angle bracket{}", if plural { "s" } else { "" }),
String::new(),
Applicability::MachineApplicable,
)
.emit();
}
}
fn parse_dot_or_call_expr_with_(&mut self, e0: P<Expr>, lo: Span) -> PResult<'a, P<Expr>> {
let mut e = e0;
let mut hi;
@ -3529,33 +3194,6 @@ impl<'a> Parser<'a> {
}
}
/// Produce an error if comparison operators are chained (RFC #558).
/// We only need to check lhs, not rhs, because all comparison ops
/// have same precedence and are left-associative
fn check_no_chained_comparison(&self, lhs: &Expr, outer_op: &AssocOp) {
debug_assert!(outer_op.is_comparison(),
"check_no_chained_comparison: {:?} is not comparison",
outer_op);
match lhs.node {
ExprKind::Binary(op, _, _) if op.node.is_comparison() => {
// respan to include both operators
let op_span = op.span.to(self.span);
let mut err = self.diagnostic().struct_span_err(op_span,
"chained comparison operators require parentheses");
if op.node == BinOpKind::Lt &&
*outer_op == AssocOp::Less || // Include `<` to provide this recommendation
*outer_op == AssocOp::Greater // even in a case like the following:
{ // Foo<Bar<Baz<Qux, ()>>>
err.help(
"use `::<...>` instead of `<...>` if you meant to specify type arguments");
err.help("or use `(...)` if you meant to specify fn arguments");
}
err.emit();
}
_ => {}
}
}
/// Parse prefix-forms of range notation: `..expr`, `..`, `..=expr`
fn parse_prefix_range_expr(&mut self,
already_parsed_attrs: Option<ThinVec<Attribute>>)
@ -3582,7 +3220,7 @@ impl<'a> Parser<'a> {
hi = x.span;
x
})?)
} else {
} else {
None
};
let limits = if tok == token::DotDot {
@ -3732,20 +3370,7 @@ impl<'a> Parser<'a> {
err.emit();
}
let in_span = self.prev_span;
if self.eat_keyword(kw::In) {
// a common typo: `for _ in in bar {}`
let mut err = self.sess.span_diagnostic.struct_span_err(
self.prev_span,
"expected iterable, found keyword `in`",
);
err.span_suggestion_short(
in_span.until(self.prev_span),
"remove the duplicated `in`",
String::new(),
Applicability::MachineApplicable,
);
err.emit();
}
self.check_for_for_in_in_typo(in_span);
let expr = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, None)?;
let (iattrs, loop_block) = self.parse_inner_attrs_and_block()?;
attrs.extend(iattrs);
@ -6327,7 +5952,9 @@ impl<'a> Parser<'a> {
let (constness, unsafety, mut asyncness, abi) = self.parse_fn_front_matter()?;
let ident = self.parse_ident()?;
let mut generics = self.parse_generics()?;
let mut decl = self.parse_fn_decl_with_self(|p| p.parse_arg())?;
let mut decl = self.parse_fn_decl_with_self(|p| {
p.parse_arg_general(true, true, false)
})?;
generics.where_clause = self.parse_where_clause()?;
self.construct_async_arguments(&mut asyncness, &mut decl);
*at_end = true;