From 9414f0b833734c344e795d590e9a845ce437c908 Mon Sep 17 00:00:00 2001 From: Wesley Wiser Date: Sat, 19 Dec 2020 16:29:38 -0500 Subject: [PATCH 1/3] Revert "Remove missing_fragment_specifier lint" This reverts commit 5ba961018c482e050af908de60e4f8bd1a00f0ae. --- compiler/rustc_lint_defs/src/builtin.rs | 17 +++++++++++++++++ .../rustc/src/lints/listing/deny-by-default.md | 3 --- 2 files changed, 17 insertions(+), 3 deletions(-) delete mode 100644 src/doc/rustc/src/lints/listing/deny-by-default.md diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 6a48b8f4dfbb2..de5253a84cc06 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -1227,6 +1227,22 @@ declare_lint! { }; } +declare_lint! { + /// The missing_fragment_specifier warning is issued when an unused pattern in a + /// `macro_rules!` macro definition has a meta-variable (e.g. `$e`) that is not + /// followed by a fragment specifier (e.g. `:expr`). + /// + /// This warning can always be fixed by removing the unused pattern in the + /// `macro_rules!` macro definition. + pub MISSING_FRAGMENT_SPECIFIER, + Deny, + "detects missing fragment specifiers in unused `macro_rules!` patterns", + @future_incompatible = FutureIncompatibleInfo { + reference: "issue #40107 ", + edition: None, + }; +} + declare_lint! { /// The `late_bound_lifetime_arguments` lint detects generic lifetime /// arguments in path segments with late bound lifetime parameters. @@ -2827,6 +2843,7 @@ declare_lint_pass! { CONST_ITEM_MUTATION, SAFE_PACKED_BORROWS, PATTERNS_IN_FNS_WITHOUT_BODY, + MISSING_FRAGMENT_SPECIFIER, LATE_BOUND_LIFETIME_ARGUMENTS, ORDER_DEPENDENT_TRAIT_OBJECTS, COHERENCE_LEAK_CHECK, diff --git a/src/doc/rustc/src/lints/listing/deny-by-default.md b/src/doc/rustc/src/lints/listing/deny-by-default.md deleted file mode 100644 index 3c1452d64676c..0000000000000 --- a/src/doc/rustc/src/lints/listing/deny-by-default.md +++ /dev/null @@ -1,3 +0,0 @@ -# Deny-by-default lints - -This file is auto-generated by the lint-docs script. From f1eb88b28a84b0533ddd036a60bb5b8acbffabb2 Mon Sep 17 00:00:00 2001 From: Wesley Wiser Date: Sat, 19 Dec 2020 16:30:56 -0500 Subject: [PATCH 2/3] Revert "Promote missing_fragment_specifier to hard error" This reverts commit 02eae432e7476a0686633a8c2b7cb1d5aab1bd2c. --- compiler/rustc_expand/src/mbe.rs | 2 +- compiler/rustc_expand/src/mbe/macro_parser.rs | 20 ++++++++++++++--- compiler/rustc_expand/src/mbe/macro_rules.rs | 15 +++++++------ compiler/rustc_expand/src/mbe/quoted.rs | 11 ++++++---- compiler/rustc_interface/src/passes.rs | 19 +++++++++++++++- compiler/rustc_session/src/parse.rs | 2 ++ src/test/ui/lint/expansion-time.rs | 4 ++++ src/test/ui/lint/expansion-time.stderr | 22 +++++++++++++++---- src/test/ui/macros/issue-39404.rs | 1 + src/test/ui/macros/issue-39404.stderr | 4 ++++ src/test/ui/macros/macro-match-nonterminal.rs | 1 + .../ui/macros/macro-match-nonterminal.stderr | 4 ++++ src/test/ui/parser/macro/issue-33569.rs | 1 - src/test/ui/parser/macro/issue-33569.stderr | 16 +++++--------- 14 files changed, 90 insertions(+), 32 deletions(-) diff --git a/compiler/rustc_expand/src/mbe.rs b/compiler/rustc_expand/src/mbe.rs index eb4aab116f00f..cbc4d14a65a1b 100644 --- a/compiler/rustc_expand/src/mbe.rs +++ b/compiler/rustc_expand/src/mbe.rs @@ -84,7 +84,7 @@ enum TokenTree { /// e.g., `$var` MetaVar(Span, Ident), /// e.g., `$var:expr`. This is only used in the left hand side of MBE macros. - MetaVarDecl(Span, Ident /* name to bind */, NonterminalKind), + MetaVarDecl(Span, Ident /* name to bind */, Option), } impl TokenTree { diff --git a/compiler/rustc_expand/src/mbe/macro_parser.rs b/compiler/rustc_expand/src/mbe/macro_parser.rs index 3cf2d8f8ac1ef..0c44f5fe9e10a 100644 --- a/compiler/rustc_expand/src/mbe/macro_parser.rs +++ b/compiler/rustc_expand/src/mbe/macro_parser.rs @@ -378,6 +378,11 @@ fn nameize>( n_rec(sess, next_m, res.by_ref(), ret_val)?; } } + TokenTree::MetaVarDecl(span, _, None) => { + if sess.missing_fragment_specifiers.borrow_mut().remove(&span).is_some() { + return Err((span, "missing fragment specifier".to_string())); + } + } TokenTree::MetaVarDecl(sp, bind_name, _) => match ret_val .entry(MacroRulesNormalizedIdent::new(bind_name)) { @@ -446,6 +451,7 @@ fn or_pat_mode(edition: Edition) -> OrPatNonterminalMode { /// /// A `ParseResult`. Note that matches are kept track of through the items generated. fn inner_parse_loop<'root, 'tt>( + sess: &ParseSess, cur_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>, next_items: &mut Vec>, eof_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>, @@ -563,9 +569,16 @@ fn inner_parse_loop<'root, 'tt>( }))); } + // We need to match a metavar (but the identifier is invalid)... this is an error + TokenTree::MetaVarDecl(span, _, None) => { + if sess.missing_fragment_specifiers.borrow_mut().remove(&span).is_some() { + return Error(span, "missing fragment specifier".to_string()); + } + } + // We need to match a metavar with a valid ident... call out to the black-box // parser by adding an item to `bb_items`. - TokenTree::MetaVarDecl(span, _, kind) => { + TokenTree::MetaVarDecl(span, _, Some(kind)) => { // Built-in nonterminals never start with these tokens, so we can eliminate // them from consideration. // @@ -640,6 +653,7 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na // parsing from the black-box parser done. The result is that `next_items` will contain a // bunch of possible next matcher positions in `next_items`. match inner_parse_loop( + parser.sess, &mut cur_items, &mut next_items, &mut eof_items, @@ -701,7 +715,7 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na let nts = bb_items .iter() .map(|item| match item.top_elts.get_tt(item.idx) { - TokenTree::MetaVarDecl(_, bind, kind) => format!("{} ('{}')", kind, bind), + TokenTree::MetaVarDecl(_, bind, Some(kind)) => format!("{} ('{}')", kind, bind), _ => panic!(), }) .collect::>() @@ -731,7 +745,7 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na assert_eq!(bb_items.len(), 1); let mut item = bb_items.pop().unwrap(); - if let TokenTree::MetaVarDecl(span, _, kind) = item.top_elts.get_tt(item.idx) { + if let TokenTree::MetaVarDecl(span, _, Some(kind)) = item.top_elts.get_tt(item.idx) { let match_cur = item.match_cur; // We use the span of the metavariable declaration to determine any // edition-specific matching behavior for non-terminals. diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs index 66463eeb90713..89d375b257da5 100644 --- a/compiler/rustc_expand/src/mbe/macro_rules.rs +++ b/compiler/rustc_expand/src/mbe/macro_rules.rs @@ -401,7 +401,7 @@ pub fn compile_declarative_macro( let diag = &sess.parse_sess.span_diagnostic; let lhs_nm = Ident::new(sym::lhs, def.span); let rhs_nm = Ident::new(sym::rhs, def.span); - let tt_spec = NonterminalKind::TT; + let tt_spec = Some(NonterminalKind::TT); // Parse the macro_rules! invocation let (macro_rules, body) = match &def.kind { @@ -578,7 +578,7 @@ fn check_lhs_no_empty_seq(sess: &ParseSess, tts: &[mbe::TokenTree]) -> bool { TokenTree::Sequence(span, ref seq) => { if seq.separator.is_none() && seq.tts.iter().all(|seq_tt| match *seq_tt { - TokenTree::MetaVarDecl(_, _, NonterminalKind::Vis) => true, + TokenTree::MetaVarDecl(_, _, Some(NonterminalKind::Vis)) => true, TokenTree::Sequence(_, ref sub_seq) => { sub_seq.kleene.op == mbe::KleeneOp::ZeroOrMore || sub_seq.kleene.op == mbe::KleeneOp::ZeroOrOne @@ -961,7 +961,7 @@ fn check_matcher_core( // Now `last` holds the complete set of NT tokens that could // end the sequence before SUFFIX. Check that every one works with `suffix`. for token in &last.tokens { - if let TokenTree::MetaVarDecl(_, name, kind) = *token { + if let TokenTree::MetaVarDecl(_, name, Some(kind)) = *token { for next_token in &suffix_first.tokens { match is_in_follow(next_token, kind) { IsInFollow::Yes => {} @@ -1019,7 +1019,7 @@ fn check_matcher_core( } fn token_can_be_followed_by_any(tok: &mbe::TokenTree) -> bool { - if let mbe::TokenTree::MetaVarDecl(_, _, kind) = *tok { + if let mbe::TokenTree::MetaVarDecl(_, _, Some(kind)) = *tok { frag_can_be_followed_by_any(kind) } else { // (Non NT's can always be followed by anything in matchers.) @@ -1123,7 +1123,7 @@ fn is_in_follow(tok: &mbe::TokenTree, kind: NonterminalKind) -> IsInFollow { } _ => IsInFollow::No(TOKENS), }, - TokenTree::MetaVarDecl(_, _, NonterminalKind::Block) => IsInFollow::Yes, + TokenTree::MetaVarDecl(_, _, Some(NonterminalKind::Block)) => IsInFollow::Yes, _ => IsInFollow::No(TOKENS), } } @@ -1158,7 +1158,7 @@ fn is_in_follow(tok: &mbe::TokenTree, kind: NonterminalKind) -> IsInFollow { TokenTree::MetaVarDecl( _, _, - NonterminalKind::Ident | NonterminalKind::Ty | NonterminalKind::Path, + Some(NonterminalKind::Ident | NonterminalKind::Ty | NonterminalKind::Path), ) => IsInFollow::Yes, _ => IsInFollow::No(TOKENS), } @@ -1171,7 +1171,8 @@ fn quoted_tt_to_string(tt: &mbe::TokenTree) -> String { match *tt { mbe::TokenTree::Token(ref token) => pprust::token_to_string(&token), mbe::TokenTree::MetaVar(_, name) => format!("${}", name), - mbe::TokenTree::MetaVarDecl(_, name, kind) => format!("${}:{}", name, kind), + mbe::TokenTree::MetaVarDecl(_, name, Some(kind)) => format!("${}:{}", name, kind), + mbe::TokenTree::MetaVarDecl(_, name, None) => format!("${}:", name), _ => panic!( "{}", "unexpected mbe::TokenTree::{Sequence or Delimited} \ diff --git a/compiler/rustc_expand/src/mbe/quoted.rs b/compiler/rustc_expand/src/mbe/quoted.rs index 48db532c78f30..01b11bb979d68 100644 --- a/compiler/rustc_expand/src/mbe/quoted.rs +++ b/compiler/rustc_expand/src/mbe/quoted.rs @@ -3,7 +3,7 @@ use crate::mbe::{Delimited, KleeneOp, KleeneToken, SequenceRepetition, TokenTree use rustc_ast::token::{self, Token}; use rustc_ast::tokenstream; -use rustc_ast::NodeId; +use rustc_ast::{NodeId, DUMMY_NODE_ID}; use rustc_ast_pretty::pprust; use rustc_session::parse::ParseSess; use rustc_span::symbol::{kw, Ident}; @@ -73,7 +73,7 @@ pub(super) fn parse( .emit(); token::NonterminalKind::Ident }); - result.push(TokenTree::MetaVarDecl(span, ident, kind)); + result.push(TokenTree::MetaVarDecl(span, ident, Some(kind))); continue; } _ => token.span, @@ -83,8 +83,11 @@ pub(super) fn parse( } tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(start_sp), }; - sess.span_diagnostic.struct_span_err(span, "missing fragment specifier").emit(); - continue; + if node_id != DUMMY_NODE_ID { + // Macros loaded from other crates have dummy node ids. + sess.missing_fragment_specifiers.borrow_mut().insert(span, node_id); + } + result.push(TokenTree::MetaVarDecl(span, ident, None)); } // Not a metavar or no matchers allowed, so just return the tree diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs index c13d26c79d738..a8c8690b9e7fa 100644 --- a/compiler/rustc_interface/src/passes.rs +++ b/compiler/rustc_interface/src/passes.rs @@ -29,6 +29,7 @@ use rustc_passes::{self, hir_stats, layout_test}; use rustc_plugin_impl as plugin; use rustc_resolve::{Resolver, ResolverArenas}; use rustc_session::config::{CrateType, Input, OutputFilenames, OutputType, PpMode, PpSourceMode}; +use rustc_session::lint; use rustc_session::output::{filename_for_input, filename_for_metadata}; use rustc_session::search_paths::PathKind; use rustc_session::Session; @@ -306,11 +307,27 @@ fn configure_and_expand_inner<'a>( ecx.check_unused_macros(); }); + let mut missing_fragment_specifiers: Vec<_> = ecx + .sess + .parse_sess + .missing_fragment_specifiers + .borrow() + .iter() + .map(|(span, node_id)| (*span, *node_id)) + .collect(); + missing_fragment_specifiers.sort_unstable_by_key(|(span, _)| *span); + + let recursion_limit_hit = ecx.reduced_recursion_limit.is_some(); + + for (span, node_id) in missing_fragment_specifiers { + let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER; + let msg = "missing fragment specifier"; + resolver.lint_buffer().buffer_lint(lint, node_id, span, msg); + } if cfg!(windows) { env::set_var("PATH", &old_path); } - let recursion_limit_hit = ecx.reduced_recursion_limit.is_some(); if recursion_limit_hit { // If we hit a recursion limit, exit early to avoid later passes getting overwhelmed // with a large AST diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs index 66c3738fb5b5a..b1a4834241730 100644 --- a/compiler/rustc_session/src/parse.rs +++ b/compiler/rustc_session/src/parse.rs @@ -119,6 +119,7 @@ pub struct ParseSess { pub unstable_features: UnstableFeatures, pub config: CrateConfig, pub edition: Edition, + pub missing_fragment_specifiers: Lock>, /// Places where raw identifiers were used. This is used for feature-gating raw identifiers. pub raw_identifier_spans: Lock>, /// Used to determine and report recursive module inclusions. @@ -152,6 +153,7 @@ impl ParseSess { unstable_features: UnstableFeatures::from_environment(None), config: FxHashSet::default(), edition: ExpnId::root().expn_data().edition, + missing_fragment_specifiers: Default::default(), raw_identifier_spans: Lock::new(Vec::new()), included_mod_stack: Lock::new(vec![]), source_map, diff --git a/src/test/ui/lint/expansion-time.rs b/src/test/ui/lint/expansion-time.rs index a9c7ac363b0b3..f23c7cb0dca14 100644 --- a/src/test/ui/lint/expansion-time.rs +++ b/src/test/ui/lint/expansion-time.rs @@ -5,6 +5,10 @@ macro_rules! foo { ( $($i:ident)* ) => { $($i)+ }; //~ WARN meta-variable repeats with different Kleene operator } +#[warn(missing_fragment_specifier)] +macro_rules! m { ($i) => {} } //~ WARN missing fragment specifier + //~| WARN this was previously accepted + #[warn(soft_unstable)] mod benches { #[bench] //~ WARN use of unstable library feature 'test' diff --git a/src/test/ui/lint/expansion-time.stderr b/src/test/ui/lint/expansion-time.stderr index 24e2733064e48..b0fc1f8e5eec7 100644 --- a/src/test/ui/lint/expansion-time.stderr +++ b/src/test/ui/lint/expansion-time.stderr @@ -12,14 +12,28 @@ note: the lint level is defined here LL | #[warn(meta_variable_misuse)] | ^^^^^^^^^^^^^^^^^^^^ +warning: missing fragment specifier + --> $DIR/expansion-time.rs:9:19 + | +LL | macro_rules! m { ($i) => {} } + | ^^ + | +note: the lint level is defined here + --> $DIR/expansion-time.rs:8:8 + | +LL | #[warn(missing_fragment_specifier)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #40107 + warning: use of unstable library feature 'test': `bench` is a part of custom test frameworks which are unstable - --> $DIR/expansion-time.rs:10:7 + --> $DIR/expansion-time.rs:14:7 | LL | #[bench] | ^^^^^ | note: the lint level is defined here - --> $DIR/expansion-time.rs:8:8 + --> $DIR/expansion-time.rs:12:8 | LL | #[warn(soft_unstable)] | ^^^^^^^^^^^^^ @@ -33,10 +47,10 @@ LL | 2 | ^ | note: the lint level is defined here - --> $DIR/expansion-time.rs:25:8 + --> $DIR/expansion-time.rs:29:8 | LL | #[warn(incomplete_include)] | ^^^^^^^^^^^^^^^^^^ -warning: 3 warnings emitted +warning: 4 warnings emitted diff --git a/src/test/ui/macros/issue-39404.rs b/src/test/ui/macros/issue-39404.rs index 054958ba00b8d..2229f2c3900c3 100644 --- a/src/test/ui/macros/issue-39404.rs +++ b/src/test/ui/macros/issue-39404.rs @@ -2,5 +2,6 @@ macro_rules! m { ($i) => {} } //~^ ERROR missing fragment specifier +//~| WARN previously accepted fn main() {} diff --git a/src/test/ui/macros/issue-39404.stderr b/src/test/ui/macros/issue-39404.stderr index 645f06e59d817..d2f2a823c2a6b 100644 --- a/src/test/ui/macros/issue-39404.stderr +++ b/src/test/ui/macros/issue-39404.stderr @@ -3,6 +3,10 @@ error: missing fragment specifier | LL | macro_rules! m { ($i) => {} } | ^^ + | + = note: `#[deny(missing_fragment_specifier)]` on by default + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #40107 error: aborting due to previous error diff --git a/src/test/ui/macros/macro-match-nonterminal.rs b/src/test/ui/macros/macro-match-nonterminal.rs index 6b023e4137274..b23e5c71c03f0 100644 --- a/src/test/ui/macros/macro-match-nonterminal.rs +++ b/src/test/ui/macros/macro-match-nonterminal.rs @@ -2,6 +2,7 @@ macro_rules! test { ($a, $b) => { //~^ ERROR missing fragment //~| ERROR missing fragment + //~| WARN this was previously accepted () }; } diff --git a/src/test/ui/macros/macro-match-nonterminal.stderr b/src/test/ui/macros/macro-match-nonterminal.stderr index 334d62812cdab..674ce3434aac6 100644 --- a/src/test/ui/macros/macro-match-nonterminal.stderr +++ b/src/test/ui/macros/macro-match-nonterminal.stderr @@ -9,6 +9,10 @@ error: missing fragment specifier | LL | ($a, $b) => { | ^^ + | + = note: `#[deny(missing_fragment_specifier)]` on by default + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #40107 error: aborting due to 2 previous errors diff --git a/src/test/ui/parser/macro/issue-33569.rs b/src/test/ui/parser/macro/issue-33569.rs index cf81f0480a2a7..80e2d7c6545ba 100644 --- a/src/test/ui/parser/macro/issue-33569.rs +++ b/src/test/ui/parser/macro/issue-33569.rs @@ -2,7 +2,6 @@ macro_rules! foo { { $+ } => { //~ ERROR expected identifier, found `+` //~^ ERROR missing fragment specifier $(x)(y) //~ ERROR expected one of: `*`, `+`, or `?` - //~^ ERROR attempted to repeat an expression containing no syntax variables } } diff --git a/src/test/ui/parser/macro/issue-33569.stderr b/src/test/ui/parser/macro/issue-33569.stderr index f54efaa6996f2..b4d38d3ce4806 100644 --- a/src/test/ui/parser/macro/issue-33569.stderr +++ b/src/test/ui/parser/macro/issue-33569.stderr @@ -4,23 +4,17 @@ error: expected identifier, found `+` LL | { $+ } => { | ^ -error: missing fragment specifier - --> $DIR/issue-33569.rs:2:8 - | -LL | { $+ } => { - | ^ - error: expected one of: `*`, `+`, or `?` --> $DIR/issue-33569.rs:4:13 | LL | $(x)(y) | ^^^ -error: attempted to repeat an expression containing no syntax variables matched as repeating at this depth - --> $DIR/issue-33569.rs:4:10 +error: missing fragment specifier + --> $DIR/issue-33569.rs:2:8 | -LL | $(x)(y) - | ^^^ +LL | { $+ } => { + | ^ -error: aborting due to 4 previous errors +error: aborting due to 3 previous errors From 56154a11473da93da0f5d57f4692991ae4972695 Mon Sep 17 00:00:00 2001 From: Wesley Wiser Date: Sun, 20 Dec 2020 21:44:27 -0500 Subject: [PATCH 3/3] Add example to lint docs --- compiler/rustc_lint_defs/src/builtin.rs | 30 ++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index de5253a84cc06..1c692d4f20762 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -1228,12 +1228,40 @@ declare_lint! { } declare_lint! { - /// The missing_fragment_specifier warning is issued when an unused pattern in a + /// The `missing_fragment_specifier` lint is issued when an unused pattern in a /// `macro_rules!` macro definition has a meta-variable (e.g. `$e`) that is not /// followed by a fragment specifier (e.g. `:expr`). /// /// This warning can always be fixed by removing the unused pattern in the /// `macro_rules!` macro definition. + /// + /// ### Example + /// + /// ```rust,compile_fail + /// macro_rules! foo { + /// () => {}; + /// ($name) => { }; + /// } + /// + /// fn main() { + /// foo!(); + /// } + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// To fix this, remove the unused pattern from the `macro_rules!` macro definition: + /// + /// ```rust + /// macro_rules! foo { + /// () => {}; + /// } + /// fn main() { + /// foo!(); + /// } + /// ``` pub MISSING_FRAGMENT_SPECIFIER, Deny, "detects missing fragment specifiers in unused `macro_rules!` patterns",