From 21944b3a108784eda5d27f2ca3b6d3769fe51a57 Mon Sep 17 00:00:00 2001 From: Mazdak Farrokhzad Date: Tue, 17 Mar 2020 14:13:32 +0100 Subject: [PATCH] expand: add recovery for parse_nt --- src/librustc_expand/mbe/macro_parser.rs | 29 +++++++++---------- src/librustc_expand/mbe/macro_rules.rs | 6 +++- src/test/ui/parser/issue-62894.stderr | 5 ++++ src/test/ui/parser/nt-parsing-has-recovery.rs | 10 +++++++ .../ui/parser/nt-parsing-has-recovery.stderr | 29 +++++++++++++++++++ 5 files changed, 63 insertions(+), 16 deletions(-) create mode 100644 src/test/ui/parser/nt-parsing-has-recovery.rs create mode 100644 src/test/ui/parser/nt-parsing-has-recovery.stderr diff --git a/src/librustc_expand/mbe/macro_parser.rs b/src/librustc_expand/mbe/macro_parser.rs index 0d777d88cad..e868b7e36aa 100644 --- a/src/librustc_expand/mbe/macro_parser.rs +++ b/src/librustc_expand/mbe/macro_parser.rs @@ -84,7 +84,7 @@ use rustc_parse::parser::{FollowedByType, Parser, PathStyle}; use rustc_session::parse::ParseSess; use rustc_span::symbol::{kw, sym, Ident, MacroRulesNormalizedIdent, Symbol}; -use rustc_errors::{FatalError, PResult}; +use rustc_errors::PResult; use rustc_span::Span; use smallvec::{smallvec, SmallVec}; @@ -271,6 +271,7 @@ crate enum ParseResult { Failure(Token, &'static str), /// Fatal error (malformed macro?). Abort compilation. Error(rustc_span::Span, String), + ErrorReported, } /// A `ParseResult` where the `Success` variant contains a mapping of @@ -652,6 +653,7 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na Success(_) => {} Failure(token, msg) => return Failure(token, msg), Error(sp, msg) => return Error(sp, msg), + ErrorReported => return ErrorReported, } // inner parse loop handled all cur_items, so it's empty @@ -735,10 +737,11 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na let mut item = bb_items.pop().unwrap(); if let TokenTree::MetaVarDecl(span, _, ident) = item.top_elts.get_tt(item.idx) { let match_cur = item.match_cur; - item.push_match( - match_cur, - MatchedNonterminal(Lrc::new(parse_nt(parser.to_mut(), span, ident.name))), - ); + let nt = match parse_nt(parser.to_mut(), span, ident.name) { + Err(()) => return ErrorReported, + Ok(nt) => nt, + }; + item.push_match(match_cur, MatchedNonterminal(Lrc::new(nt))); item.idx += 1; item.match_cur += 1; } else { @@ -849,20 +852,16 @@ fn may_begin_with(token: &Token, name: Name) -> bool { /// # Returns /// /// The parsed non-terminal. -fn parse_nt(p: &mut Parser<'_>, sp: Span, name: Symbol) -> Nonterminal { +fn parse_nt(p: &mut Parser<'_>, sp: Span, name: Symbol) -> Result { // FIXME(Centril): Consider moving this to `parser.rs` to make // the visibilities of the methods used below `pub(super)` at most. - if name == sym::tt { - return token::NtTT(p.parse_token_tree()); - } - match parse_nt_inner(p, sp, name) { - Ok(nt) => nt, - Err(mut err) => { - err.emit(); - FatalError.raise(); - } + return Ok(token::NtTT(p.parse_token_tree())); } + parse_nt_inner(p, sp, name).map_err(|mut err| { + err.span_label(sp, format!("while parsing argument for this `{}` macro fragment", name)) + .emit() + }) } fn parse_nt_inner<'a>(p: &mut Parser<'a>, sp: Span, name: Symbol) -> PResult<'a, Nonterminal> { diff --git a/src/librustc_expand/mbe/macro_rules.rs b/src/librustc_expand/mbe/macro_rules.rs index 6377347585c..43bc72090bc 100644 --- a/src/librustc_expand/mbe/macro_rules.rs +++ b/src/librustc_expand/mbe/macro_rules.rs @@ -4,7 +4,7 @@ use crate::expand::{ensure_complete_parse, parse_ast_fragment, AstFragment, AstF use crate::mbe; use crate::mbe::macro_check; use crate::mbe::macro_parser::parse_tt; -use crate::mbe::macro_parser::{Error, Failure, Success}; +use crate::mbe::macro_parser::{Error, ErrorReported, Failure, Success}; use crate::mbe::macro_parser::{MatchedNonterminal, MatchedSeq}; use crate::mbe::transcribe::transcribe; @@ -317,6 +317,7 @@ fn generic_extension<'cx>( cx.struct_span_err(span, &msg).emit(); return DummyResult::any(span); } + ErrorReported => return DummyResult::any(sp), } // The matcher was not `Success(..)`ful. @@ -448,6 +449,9 @@ pub fn compile_declarative_macro( sess.span_diagnostic.struct_span_err(sp.substitute_dummy(def.span), &msg).emit(); return mk_syn_ext(Box::new(MacroRulesDummyExpander)); } + ErrorReported => { + return mk_syn_ext(Box::new(MacroRulesDummyExpander)); + } }; let mut valid = true; diff --git a/src/test/ui/parser/issue-62894.stderr b/src/test/ui/parser/issue-62894.stderr index 6db380f7a7f..73e3552e3ec 100644 --- a/src/test/ui/parser/issue-62894.stderr +++ b/src/test/ui/parser/issue-62894.stderr @@ -42,6 +42,11 @@ LL | fn f() { assert_eq!(f(), (), assert_eq!(assert_eq! LL | LL | fn main() {} | ^^ unexpected token + | + ::: $SRC_DIR/libcore/macros/mod.rs:LL:COL + | +LL | ($left:expr, $right:expr) => ({ + | ---------- while parsing argument for this `expr` macro fragment error: aborting due to 4 previous errors diff --git a/src/test/ui/parser/nt-parsing-has-recovery.rs b/src/test/ui/parser/nt-parsing-has-recovery.rs new file mode 100644 index 00000000000..ccbeb398af5 --- /dev/null +++ b/src/test/ui/parser/nt-parsing-has-recovery.rs @@ -0,0 +1,10 @@ +macro_rules! foo { + ($e:expr) => {} +} + +foo!(1 + @); //~ ERROR expected expression, found `@` +foo!(1 + @); //~ ERROR expected expression, found `@` + +fn main() { + let _recovery_witness: () = 0; //~ ERROR mismatched types +} diff --git a/src/test/ui/parser/nt-parsing-has-recovery.stderr b/src/test/ui/parser/nt-parsing-has-recovery.stderr new file mode 100644 index 00000000000..263c4ad5361 --- /dev/null +++ b/src/test/ui/parser/nt-parsing-has-recovery.stderr @@ -0,0 +1,29 @@ +error: expected expression, found `@` + --> $DIR/nt-parsing-has-recovery.rs:5:10 + | +LL | ($e:expr) => {} + | ------- while parsing argument for this `expr` macro fragment +... +LL | foo!(1 + @); + | ^ expected expression + +error: expected expression, found `@` + --> $DIR/nt-parsing-has-recovery.rs:6:10 + | +LL | ($e:expr) => {} + | ------- while parsing argument for this `expr` macro fragment +... +LL | foo!(1 + @); + | ^ expected expression + +error[E0308]: mismatched types + --> $DIR/nt-parsing-has-recovery.rs:9:33 + | +LL | let _recovery_witness: () = 0; + | -- ^ expected `()`, found integer + | | + | expected due to this + +error: aborting due to 3 previous errors + +For more information about this error, try `rustc --explain E0308`.