diff options
| -rw-r--r-- | compiler/rustc_expand/src/mbe/macro_parser.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_expand/src/mbe/macro_rules.rs | 247 |
2 files changed, 129 insertions, 124 deletions
diff --git a/compiler/rustc_expand/src/mbe/macro_parser.rs b/compiler/rustc_expand/src/mbe/macro_parser.rs index 0402c51247a..d2dbd190c8e 100644 --- a/compiler/rustc_expand/src/mbe/macro_parser.rs +++ b/compiler/rustc_expand/src/mbe/macro_parser.rs @@ -277,7 +277,11 @@ pub(crate) enum ParseResult<T> { /// A `ParseResult` where the `Success` variant contains a mapping of /// `MacroRulesNormalizedIdent`s to `NamedMatch`es. This represents the mapping /// of metavars to the token trees they bind to. -pub(crate) type NamedParseResult = ParseResult<FxHashMap<MacroRulesNormalizedIdent, NamedMatch>>; +pub(crate) type NamedParseResult = ParseResult<NamedMatches>; + +/// Contains a mapping of `MacroRulesNormalizedIdent`s to `NamedMatch`es. +/// This represents the mapping of metavars to the token trees they bind to. +pub(crate) type NamedMatches = FxHashMap<MacroRulesNormalizedIdent, NamedMatch>; /// Count how many metavars declarations are in `matcher`. pub(super) fn count_metavar_decls(matcher: &[TokenTree]) -> usize { diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs index 9c676a41f3a..b35ec453145 100644 --- a/compiler/rustc_expand/src/mbe/macro_rules.rs +++ b/compiler/rustc_expand/src/mbe/macro_rules.rs @@ -14,7 +14,9 @@ use rustc_ast::{NodeId, DUMMY_NODE_ID}; use rustc_ast_pretty::pprust; use rustc_attr::{self as attr, TransparencyError}; use rustc_data_structures::fx::{FxHashMap, FxIndexMap}; -use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, DiagnosticMessage}; +use rustc_errors::{ + Applicability, Diagnostic, DiagnosticBuilder, DiagnosticMessage, ErrorGuaranteed, +}; use rustc_feature::Features; use rustc_lint_defs::builtin::{ RUST_2021_INCOMPATIBLE_OR_PATTERNS, SEMICOLON_IN_EXPRESSIONS_FROM_MACROS, @@ -33,7 +35,7 @@ use std::borrow::Cow; use std::collections::hash_map::Entry; use std::{mem, slice}; -use super::macro_parser::NamedParseResult; +use super::macro_parser::{NamedMatches, NamedParseResult}; pub(crate) struct ParserAnyMacro<'a> { parser: Parser<'a>, @@ -253,9 +255,87 @@ fn expand_macro<'cx>( trace_macros_note(&mut cx.expansions, sp, msg); } - // Which arm's failure should we report? (the one furthest along) - let mut best_failure: Option<(Token, &str)> = None; + // Track nothing for the best performance + let try_success_result = try_match_macro(sess, name, &arg, lhses, &mut NoopTracker); + + match try_success_result { + Ok((i, named_matches)) => { + let (rhs, rhs_span): (&mbe::Delimited, DelimSpan) = match &rhses[i] { + mbe::TokenTree::Delimited(span, delimited) => (&delimited, *span), + _ => cx.span_bug(sp, "malformed macro rhs"), + }; + let arm_span = rhses[i].span(); + + let rhs_spans = rhs.tts.iter().map(|t| t.span()).collect::<Vec<_>>(); + // rhs has holes ( `$id` and `$(...)` that need filled) + let mut tts = match transcribe(cx, &named_matches, &rhs, rhs_span, transparency) { + Ok(tts) => tts, + Err(mut err) => { + err.emit(); + return DummyResult::any(arm_span); + } + }; + + // Replace all the tokens for the corresponding positions in the macro, to maintain + // proper positions in error reporting, while maintaining the macro_backtrace. + if rhs_spans.len() == tts.len() { + tts = tts.map_enumerated(|i, tt| { + let mut tt = tt.clone(); + let mut sp = rhs_spans[i]; + sp = sp.with_ctxt(tt.span().ctxt()); + tt.set_span(sp); + tt + }); + } + + if cx.trace_macros() { + let msg = format!("to `{}`", pprust::tts_to_string(&tts)); + trace_macros_note(&mut cx.expansions, sp, msg); + } + + let mut p = Parser::new(sess, tts, false, None); + p.last_type_ascription = cx.current_expansion.prior_type_ascription; + + if is_local { + cx.resolver.record_macro_rule_usage(node_id, i); + } + + // Let the context choose how to interpret the result. + // Weird, but useful for X-macros. + return Box::new(ParserAnyMacro { + parser: p, + + // Pass along the original expansion site and the name of the macro + // so we can print a useful error message if the parse of the expanded + // macro leaves unparsed tokens. + site_span: sp, + macro_ident: name, + lint_node_id: cx.current_expansion.lint_node_id, + is_trailing_mac: cx.current_expansion.is_trailing_mac, + arm_span, + is_local, + }); + } + Err(()) => { + todo!("Retry macro invocation while tracking diagnostics info and emit error"); + + return DummyResult::any(sp); + } + } + + DummyResult::any(sp) +} +/// Try expanding the macro. Returns the index of the sucessful arm and its named_matches if it was successful, +/// and nothing if it failed. On failure, it's the callers job to use `track` accordingly to record all errors +/// correctly. +fn try_match_macro<'matcher, T: Tracker<'matcher>>( + sess: &ParseSess, + name: Ident, + arg: &TokenStream, + lhses: &'matcher [Vec<MatcherLoc>], + track: &mut T, +) -> Result<(usize, NamedMatches), ()> { // We create a base parser that can be used for the "black box" parts. // Every iteration needs a fresh copy of that parser. However, the parser // is not mutated on many of the iterations, particularly when dealing with @@ -277,7 +357,6 @@ fn expand_macro<'cx>( // this situation.) // FIXME(Nilstrieb): Stop recovery from happening on this parser and retry later with recovery if the macro failed to match. let parser = parser_from_cx(sess, arg.clone()); - // Try each arm's matchers. let mut tt_parser = TtParser::new(name); for (i, lhs) in lhses.iter().enumerate() { @@ -287,115 +366,36 @@ fn expand_macro<'cx>( // are not recorded. On the first `Success(..)`ful matcher, the spans are merged. let mut gated_spans_snapshot = mem::take(&mut *sess.gated_spans.spans.borrow_mut()); - match tt_parser.parse_tt(&mut Cow::Borrowed(&parser), lhs, &mut NoopTracker) { + let result = tt_parser.parse_tt(&mut Cow::Borrowed(&parser), lhs, track); + + track.after_arm(&result); + + match result { Success(named_matches) => { // The matcher was `Success(..)`ful. // Merge the gated spans from parsing the matcher with the pre-existing ones. sess.gated_spans.merge(gated_spans_snapshot); - let (rhs, rhs_span): (&mbe::Delimited, DelimSpan) = match &rhses[i] { - mbe::TokenTree::Delimited(span, delimited) => (&delimited, *span), - _ => cx.span_bug(sp, "malformed macro rhs"), - }; - let arm_span = rhses[i].span(); - - let rhs_spans = rhs.tts.iter().map(|t| t.span()).collect::<Vec<_>>(); - // rhs has holes ( `$id` and `$(...)` that need filled) - let mut tts = match transcribe(cx, &named_matches, &rhs, rhs_span, transparency) { - Ok(tts) => tts, - Err(mut err) => { - err.emit(); - return DummyResult::any(arm_span); - } - }; - - // Replace all the tokens for the corresponding positions in the macro, to maintain - // proper positions in error reporting, while maintaining the macro_backtrace. - if rhs_spans.len() == tts.len() { - tts = tts.map_enumerated(|i, tt| { - let mut tt = tt.clone(); - let mut sp = rhs_spans[i]; - sp = sp.with_ctxt(tt.span().ctxt()); - tt.set_span(sp); - tt - }); - } - - if cx.trace_macros() { - let msg = format!("to `{}`", pprust::tts_to_string(&tts)); - trace_macros_note(&mut cx.expansions, sp, msg); - } - - let mut p = Parser::new(sess, tts, false, None); - p.last_type_ascription = cx.current_expansion.prior_type_ascription; - - if is_local { - cx.resolver.record_macro_rule_usage(node_id, i); - } - - // Let the context choose how to interpret the result. - // Weird, but useful for X-macros. - return Box::new(ParserAnyMacro { - parser: p, - - // Pass along the original expansion site and the name of the macro - // so we can print a useful error message if the parse of the expanded - // macro leaves unparsed tokens. - site_span: sp, - macro_ident: name, - lint_node_id: cx.current_expansion.lint_node_id, - is_trailing_mac: cx.current_expansion.is_trailing_mac, - arm_span, - is_local, - }); + return Ok((i, named_matches)); } - Failure(token, msg) => match best_failure { - Some((ref best_token, _)) if best_token.span.lo() >= token.span.lo() => {} - _ => best_failure = Some((token, msg)), - }, - Error(err_sp, ref msg) => { - let span = err_sp.substitute_dummy(sp); - cx.struct_span_err(span, &msg).emit(); - return DummyResult::any(span); + Failure(_, _) => { + // Try the next arm + } + Error(_, _) => { + // We haven't emitted an error yet + return Err(()); + } + ErrorReported(_) => { + return Err(()); } - ErrorReported(_) => return DummyResult::any(sp), } // The matcher was not `Success(..)`ful. // Restore to the state before snapshotting and maybe try again. mem::swap(&mut gated_spans_snapshot, &mut sess.gated_spans.spans.borrow_mut()); } - drop(parser); - - let (token, label) = best_failure.expect("ran no matchers"); - let span = token.span.substitute_dummy(sp); - let mut err = cx.struct_span_err(span, &parse_failure_msg(&token)); - err.span_label(span, label); - if !def_span.is_dummy() && !cx.source_map().is_imported(def_span) { - err.span_label(cx.source_map().guess_head_span(def_span), "when calling this macro"); - } - annotate_doc_comment(&mut err, sess.source_map(), span); - // Check whether there's a missing comma in this macro call, like `println!("{}" a);` - if let Some((arg, comma_span)) = arg.add_comma() { - for lhs in lhses { - let parser = parser_from_cx(sess, arg.clone()); - if let Success(_) = tt_parser.parse_tt(&mut Cow::Borrowed(&parser), lhs, &mut NoopTracker) { - if comma_span.is_dummy() { - err.note("you might be missing a comma"); - } else { - err.span_suggestion_short( - comma_span, - "missing comma here", - ", ", - Applicability::MachineApplicable, - ); - } - } - } - } - err.emit(); - cx.trace_macros_diag(); - DummyResult::any(sp) + + Err(()) } // Note that macro-by-example's input is also matched against a token tree: @@ -477,28 +477,29 @@ pub fn compile_declarative_macro( let parser = Parser::new(&sess.parse_sess, body, true, rustc_parse::MACRO_ARGUMENTS); let mut tt_parser = TtParser::new(Ident::with_dummy_span(if macro_rules { kw::MacroRules } else { kw::Macro })); - let argument_map = match tt_parser.parse_tt(&mut Cow::Borrowed(&parser), &argument_gram, &mut NoopTracker) { - Success(m) => m, - Failure(token, msg) => { - let s = parse_failure_msg(&token); - let sp = token.span.substitute_dummy(def.span); - let mut err = sess.parse_sess.span_diagnostic.struct_span_err(sp, &s); - err.span_label(sp, msg); - annotate_doc_comment(&mut err, sess.source_map(), sp); - err.emit(); - return dummy_syn_ext(); - } - Error(sp, msg) => { - sess.parse_sess - .span_diagnostic - .struct_span_err(sp.substitute_dummy(def.span), &msg) - .emit(); - return dummy_syn_ext(); - } - ErrorReported(_) => { - return dummy_syn_ext(); - } - }; + let argument_map = + match tt_parser.parse_tt(&mut Cow::Borrowed(&parser), &argument_gram, &mut NoopTracker) { + Success(m) => m, + Failure(token, msg) => { + let s = parse_failure_msg(&token); + let sp = token.span.substitute_dummy(def.span); + let mut err = sess.parse_sess.span_diagnostic.struct_span_err(sp, &s); + err.span_label(sp, msg); + annotate_doc_comment(&mut err, sess.source_map(), sp); + err.emit(); + return dummy_syn_ext(); + } + Error(sp, msg) => { + sess.parse_sess + .span_diagnostic + .struct_span_err(sp.substitute_dummy(def.span), &msg) + .emit(); + return dummy_syn_ext(); + } + ErrorReported(_) => { + return dummy_syn_ext(); + } + }; let mut valid = true; |