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Auto merge of #56999 - petrochenkov:macrecov2, r=estebank
AST/HIR: Introduce `ExprKind::Err` for better error recovery in the front-end This way we can avoid aborting compilation if expansion produces errors and generate `ExprKind::Err`s instead.
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127 files changed

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‎src/librustc/cfg/construct.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -392,7 +392,8 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
392392

393393
hir::ExprKind::Closure(..) |
394394
hir::ExprKind::Lit(..) |
395-
hir::ExprKind::Path(_) => {
395+
hir::ExprKind::Path(_) |
396+
hir::ExprKind::Err => {
396397
self.straightline(expr, pred, None::<hir::Expr>.iter())
397398
}
398399
}

‎src/librustc/hir/intravisit.rs

+1
Original file line numberDiff line numberDiff line change
@@ -1099,6 +1099,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
10991099
ExprKind::Yield(ref subexpression) => {
11001100
visitor.visit_expr(subexpression);
11011101
}
1102+
ExprKind::Err => {}
11021103
}
11031104
}
11041105

‎src/librustc/hir/lowering.rs

+2-3
Original file line numberDiff line numberDiff line change
@@ -2709,7 +2709,6 @@ impl<'a> LoweringContext<'a> {
27092709
rules: self.lower_block_check_mode(&b.rules),
27102710
span: b.span,
27112711
targeted_by_break,
2712-
recovered: b.recovered,
27132712
})
27142713
}
27152714

@@ -3781,7 +3780,6 @@ impl<'a> LoweringContext<'a> {
37813780
rules: hir::DefaultBlock,
37823781
span,
37833782
targeted_by_break: false,
3784-
recovered: blk.recovered,
37853783
});
37863784
P(self.expr_block(blk, ThinVec::new()))
37873785
}
@@ -4117,6 +4115,8 @@ impl<'a> LoweringContext<'a> {
41174115
hir::ExprKind::Yield(P(expr))
41184116
}
41194117

4118+
ExprKind::Err => hir::ExprKind::Err,
4119+
41204120
// Desugar `ExprIfLet`
41214121
// from: `if let <pat> = <sub_expr> <body> [<else_opt>]`
41224122
ExprKind::IfLet(ref pats, ref sub_expr, ref body, ref else_opt) => {
@@ -4821,7 +4821,6 @@ impl<'a> LoweringContext<'a> {
48214821
rules: hir::DefaultBlock,
48224822
span,
48234823
targeted_by_break: false,
4824-
recovered: false,
48254824
}
48264825
}
48274826

‎src/librustc/hir/mod.rs

+6-6
Original file line numberDiff line numberDiff line change
@@ -807,11 +807,6 @@ pub struct Block {
807807
/// break out of this block early.
808808
/// Used by `'label: {}` blocks and by `catch` statements.
809809
pub targeted_by_break: bool,
810-
/// If true, don't emit return value type errors as the parser had
811-
/// to recover from a parse error so this block will not have an
812-
/// appropriate type. A parse error will have been emitted so the
813-
/// compilation will never succeed if this is true.
814-
pub recovered: bool,
815810
}
816811

817812
#[derive(Clone, RustcEncodable, RustcDecodable)]
@@ -1362,6 +1357,7 @@ impl Expr {
13621357
ExprKind::Struct(..) => ExprPrecedence::Struct,
13631358
ExprKind::Repeat(..) => ExprPrecedence::Repeat,
13641359
ExprKind::Yield(..) => ExprPrecedence::Yield,
1360+
ExprKind::Err => ExprPrecedence::Err,
13651361
}
13661362
}
13671363

@@ -1412,7 +1408,8 @@ impl Expr {
14121408
ExprKind::AddrOf(..) |
14131409
ExprKind::Binary(..) |
14141410
ExprKind::Yield(..) |
1415-
ExprKind::Cast(..) => {
1411+
ExprKind::Cast(..) |
1412+
ExprKind::Err => {
14161413
false
14171414
}
14181415
}
@@ -1525,6 +1522,9 @@ pub enum ExprKind {
15251522

15261523
/// A suspension point for generators. This is `yield <expr>` in Rust.
15271524
Yield(P<Expr>),
1525+
1526+
/// Placeholder for an expression that wasn't syntactically well formed in some way.
1527+
Err,
15281528
}
15291529

15301530
/// Optionally `Self`-qualified value/type path or associated extension.

‎src/librustc/hir/print.rs

+8-1
Original file line numberDiff line numberDiff line change
@@ -430,7 +430,9 @@ impl<'a> State<'a> {
430430
self.s.word("_")?;
431431
}
432432
hir::TyKind::Err => {
433-
self.s.word("?")?;
433+
self.popen()?;
434+
self.s.word("/*ERROR*/")?;
435+
self.pclose()?;
434436
}
435437
}
436438
self.end()
@@ -1540,6 +1542,11 @@ impl<'a> State<'a> {
15401542
self.word_space("yield")?;
15411543
self.print_expr_maybe_paren(&expr, parser::PREC_JUMP)?;
15421544
}
1545+
hir::ExprKind::Err => {
1546+
self.popen()?;
1547+
self.s.word("/*ERROR*/")?;
1548+
self.pclose()?;
1549+
}
15431550
}
15441551
self.ann.post(self, AnnNode::Expr(expr))?;
15451552
self.end()

‎src/librustc/ich/impls_hir.rs

+2-2
Original file line numberDiff line numberDiff line change
@@ -410,7 +410,6 @@ impl_stable_hash_for!(struct hir::Block {
410410
rules,
411411
span,
412412
targeted_by_break,
413-
recovered,
414413
});
415414

416415
impl_stable_hash_for!(struct hir::Pat {
@@ -592,7 +591,8 @@ impl_stable_hash_for!(enum hir::ExprKind {
592591
InlineAsm(asm, inputs, outputs),
593592
Struct(path, fields, base),
594593
Repeat(val, times),
595-
Yield(val)
594+
Yield(val),
595+
Err
596596
});
597597

598598
impl_stable_hash_for!(enum hir::LocalSource {

‎src/librustc/lint/levels.rs

+2-4
Original file line numberDiff line numberDiff line change
@@ -222,24 +222,22 @@ impl<'a> LintLevelsBuilder<'a> {
222222
match item.node {
223223
ast::MetaItemKind::Word => {} // actual lint names handled later
224224
ast::MetaItemKind::NameValue(ref name_value) => {
225-
let gate_reasons = !self.sess.features_untracked().lint_reasons;
226225
if item.ident == "reason" {
227226
// found reason, reslice meta list to exclude it
228227
metas = &metas[0..metas.len()-1];
229228
// FIXME (#55112): issue unused-attributes lint if we thereby
230229
// don't have any lint names (`#[level(reason = "foo")]`)
231230
if let ast::LitKind::Str(rationale, _) = name_value.node {
232-
if gate_reasons {
231+
if !self.sess.features_untracked().lint_reasons {
233232
feature_gate::emit_feature_err(
234233
&self.sess.parse_sess,
235234
"lint_reasons",
236235
item.span,
237236
feature_gate::GateIssue::Language,
238237
"lint reasons are experimental"
239238
);
240-
} else {
241-
reason = Some(rationale);
242239
}
240+
reason = Some(rationale);
243241
} else {
244242
let mut err = bad_attr(name_value.span);
245243
err.help("reason must be a string literal");

‎src/librustc/middle/expr_use_visitor.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -479,7 +479,8 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
479479
}
480480

481481
hir::ExprKind::Continue(..) |
482-
hir::ExprKind::Lit(..) => {}
482+
hir::ExprKind::Lit(..) |
483+
hir::ExprKind::Err => {}
483484

484485
hir::ExprKind::Loop(ref blk, _, _) => {
485486
self.walk_block(&blk);

‎src/librustc/middle/liveness.rs

+4-2
Original file line numberDiff line numberDiff line change
@@ -515,6 +515,7 @@ fn visit_expr<'a, 'tcx>(ir: &mut IrMaps<'a, 'tcx>, expr: &'tcx Expr) {
515515
hir::ExprKind::Box(..) |
516516
hir::ExprKind::Yield(..) |
517517
hir::ExprKind::Type(..) |
518+
hir::ExprKind::Err |
518519
hir::ExprKind::Path(hir::QPath::TypeRelative(..)) => {
519520
intravisit::walk_expr(ir, expr);
520521
}
@@ -1254,7 +1255,8 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
12541255
self.propagate_through_exprs(inputs, succ)
12551256
}
12561257

1257-
hir::ExprKind::Lit(..) | hir::ExprKind::Path(hir::QPath::TypeRelative(..)) => {
1258+
hir::ExprKind::Lit(..) | hir::ExprKind::Err |
1259+
hir::ExprKind::Path(hir::QPath::TypeRelative(..)) => {
12581260
succ
12591261
}
12601262

@@ -1521,7 +1523,7 @@ fn check_expr<'a, 'tcx>(this: &mut Liveness<'a, 'tcx>, expr: &'tcx Expr) {
15211523
hir::ExprKind::Block(..) | hir::ExprKind::AddrOf(..) |
15221524
hir::ExprKind::Struct(..) | hir::ExprKind::Repeat(..) |
15231525
hir::ExprKind::Closure(..) | hir::ExprKind::Path(_) | hir::ExprKind::Yield(..) |
1524-
hir::ExprKind::Box(..) | hir::ExprKind::Type(..) => {
1526+
hir::ExprKind::Box(..) | hir::ExprKind::Type(..) | hir::ExprKind::Err => {
15251527
intravisit::walk_expr(this, expr);
15261528
}
15271529
}

‎src/librustc/middle/mem_categorization.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -687,7 +687,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
687687
hir::ExprKind::Block(..) | hir::ExprKind::Loop(..) | hir::ExprKind::Match(..) |
688688
hir::ExprKind::Lit(..) | hir::ExprKind::Break(..) |
689689
hir::ExprKind::Continue(..) | hir::ExprKind::Struct(..) | hir::ExprKind::Repeat(..) |
690-
hir::ExprKind::InlineAsm(..) | hir::ExprKind::Box(..) => {
690+
hir::ExprKind::InlineAsm(..) | hir::ExprKind::Box(..) | hir::ExprKind::Err => {
691691
Ok(self.cat_rvalue_node(expr.hir_id, expr.span, expr_ty))
692692
}
693693
}

‎src/librustc_driver/driver.rs

-10
Original file line numberDiff line numberDiff line change
@@ -987,7 +987,6 @@ where
987987
};
988988

989989
let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
990-
let err_count = ecx.parse_sess.span_diagnostic.err_count();
991990

992991
// Expand macros now!
993992
let krate = time(sess, "expand crate", || {
@@ -1013,9 +1012,6 @@ where
10131012
let msg = "missing fragment specifier";
10141013
sess.buffer_lint(lint, ast::CRATE_NODE_ID, span, msg);
10151014
}
1016-
if ecx.parse_sess.span_diagnostic.err_count() - ecx.resolve_err_count > err_count {
1017-
ecx.parse_sess.span_diagnostic.abort_if_errors();
1018-
}
10191015
if cfg!(windows) {
10201016
env::set_var("PATH", &old_path);
10211017
}
@@ -1119,12 +1115,6 @@ where
11191115
})
11201116
})?;
11211117

1122-
// Unresolved macros might be due to mistyped `#[macro_use]`,
1123-
// so abort after checking for unknown attributes. (#49074)
1124-
if resolver.found_unresolved_macro {
1125-
sess.diagnostic().abort_if_errors();
1126-
}
1127-
11281118
// Lower ast -> hir.
11291119
// First, we need to collect the dep_graph.
11301120
let dep_graph = match future_dep_graph {

‎src/librustc_driver/pretty.rs

+2-4
Original file line numberDiff line numberDiff line change
@@ -741,15 +741,13 @@ impl<'a> fold::Folder for ReplaceBodyWithLoop<'a> {
741741

742742
fn fold_block(&mut self, b: P<ast::Block>) -> P<ast::Block> {
743743
fn stmt_to_block(rules: ast::BlockCheckMode,
744-
recovered: bool,
745744
s: Option<ast::Stmt>,
746745
sess: &Session) -> ast::Block {
747746
ast::Block {
748747
stmts: s.into_iter().collect(),
749748
rules,
750749
id: sess.next_node_id(),
751750
span: syntax_pos::DUMMY_SP,
752-
recovered,
753751
}
754752
}
755753

@@ -768,7 +766,7 @@ impl<'a> fold::Folder for ReplaceBodyWithLoop<'a> {
768766
}
769767
}
770768

771-
let empty_block = stmt_to_block(BlockCheckMode::Default, false, None, self.sess);
769+
let empty_block = stmt_to_block(BlockCheckMode::Default, None, self.sess);
772770
let loop_expr = P(ast::Expr {
773771
node: ast::ExprKind::Loop(P(empty_block), None),
774772
id: self.sess.next_node_id(),
@@ -809,7 +807,7 @@ impl<'a> fold::Folder for ReplaceBodyWithLoop<'a> {
809807
old_blocks.push(new_block);
810808
}
811809

812-
stmt_to_block(b.rules, b.recovered, Some(loop_stmt), self.sess)
810+
stmt_to_block(b.rules, Some(loop_stmt), self.sess)
813811
} else {
814812
//push `loop {}` onto the end of our fresh block and yield that
815813
new_block.stmts.push(loop_stmt);

‎src/librustc_mir/hair/cx/expr.rs

+1
Original file line numberDiff line numberDiff line change
@@ -780,6 +780,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
780780
hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
781781

782782
hir::ExprKind::Yield(ref v) => ExprKind::Yield { value: v.to_ref() },
783+
hir::ExprKind::Err => unreachable!(),
783784
};
784785

785786
Expr {

‎src/librustc_passes/ast_validation.rs

-30
Original file line numberDiff line numberDiff line change
@@ -278,25 +278,6 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
278278
visit::walk_ty(self, ty)
279279
}
280280

281-
fn visit_use_tree(&mut self, use_tree: &'a UseTree, id: NodeId, _nested: bool) {
282-
// Check if the path in this `use` is not generic, such as `use foo::bar<T>;` While this
283-
// can't happen normally thanks to the parser, a generic might sneak in if the `use` is
284-
// built using a macro.
285-
//
286-
// macro_use foo {
287-
// ($p:path) => { use $p; }
288-
// }
289-
// foo!(bar::baz<T>);
290-
use_tree.prefix.segments.iter().find(|segment| {
291-
segment.args.is_some()
292-
}).map(|segment| {
293-
self.err_handler().span_err(segment.args.as_ref().unwrap().span(),
294-
"generic arguments in import path");
295-
});
296-
297-
visit::walk_use_tree(self, use_tree, id);
298-
}
299-
300281
fn visit_label(&mut self, label: &'a Label) {
301282
self.check_label(label.ident);
302283
visit::walk_label(self, label);
@@ -433,17 +414,6 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
433414
visit::walk_foreign_item(self, fi)
434415
}
435416

436-
fn visit_vis(&mut self, vis: &'a Visibility) {
437-
if let VisibilityKind::Restricted { ref path, .. } = vis.node {
438-
path.segments.iter().find(|segment| segment.args.is_some()).map(|segment| {
439-
self.err_handler().span_err(segment.args.as_ref().unwrap().span(),
440-
"generic arguments in visibility path");
441-
});
442-
}
443-
444-
visit::walk_vis(self, vis)
445-
}
446-
447417
fn visit_generics(&mut self, generics: &'a Generics) {
448418
let mut seen_non_lifetime_param = false;
449419
let mut seen_default = None;

‎src/librustc_passes/rvalue_promotion.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -449,7 +449,8 @@ fn check_expr_kind<'a, 'tcx>(
449449
struct_result
450450
}
451451

452-
hir::ExprKind::Lit(_) => Promotable,
452+
hir::ExprKind::Lit(_) |
453+
hir::ExprKind::Err => Promotable,
453454

454455
hir::ExprKind::AddrOf(_, ref expr) |
455456
hir::ExprKind::Repeat(ref expr, _) => {

‎src/librustc_resolve/lib.rs

+4-3
Original file line numberDiff line numberDiff line change
@@ -1576,7 +1576,6 @@ pub struct Resolver<'a> {
15761576
macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
15771577
macro_defs: FxHashMap<Mark, DefId>,
15781578
local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
1579-
pub found_unresolved_macro: bool,
15801579

15811580
/// List of crate local macros that we need to warn about as being unused.
15821581
/// Right now this only includes macro_rules! macros, and macros 2.0.
@@ -1911,7 +1910,6 @@ impl<'a> Resolver<'a> {
19111910
name_already_seen: FxHashMap::default(),
19121911
potentially_unused_imports: Vec::new(),
19131912
struct_constructors: Default::default(),
1914-
found_unresolved_macro: false,
19151913
unused_macros: FxHashSet::default(),
19161914
current_type_ascription: Vec::new(),
19171915
injected_crate: None,
@@ -2024,8 +2022,10 @@ impl<'a> Resolver<'a> {
20242022
record_used_id: Option<NodeId>,
20252023
path_span: Span)
20262024
-> Option<LexicalScopeBinding<'a>> {
2027-
let record_used = record_used_id.is_some();
20282025
assert!(ns == TypeNS || ns == ValueNS);
2026+
if ident.name == keywords::Invalid.name() {
2027+
return Some(LexicalScopeBinding::Def(Def::Err));
2028+
}
20292029
if ns == TypeNS {
20302030
ident.span = if ident.name == keywords::SelfUpper.name() {
20312031
// FIXME(jseyfried) improve `Self` hygiene
@@ -2038,6 +2038,7 @@ impl<'a> Resolver<'a> {
20382038
}
20392039

20402040
// Walk backwards up the ribs in scope.
2041+
let record_used = record_used_id.is_some();
20412042
let mut module = self.graph_root;
20422043
for i in (0 .. self.ribs[ns].len()).rev() {
20432044
if let Some(def) = self.ribs[ns][i].bindings.get(&ident).cloned() {

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