forked from swiftlang/swift
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathParsePattern.cpp
1247 lines (1088 loc) · 44.5 KB
/
ParsePattern.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
//===--- ParsePattern.cpp - Swift Language Parser for Patterns ------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// Pattern Parsing and AST Building
//
//===----------------------------------------------------------------------===//
#include "swift/Parse/Parser.h"
#include "swift/AST/ASTWalker.h"
#include "swift/AST/Initializer.h"
#include "swift/AST/Module.h"
#include "swift/Basic/StringExtras.h"
#include "swift/Parse/CodeCompletionCallbacks.h"
#include "swift/Parse/SyntaxParsingContext.h"
#include "swift/Syntax/SyntaxFactory.h"
#include "swift/Syntax/TokenSyntax.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/SaveAndRestore.h"
using namespace swift;
using namespace swift::syntax;
/// \brief Determine the kind of a default argument given a parsed
/// expression that has not yet been type-checked.
static DefaultArgumentKind getDefaultArgKind(Expr *init) {
if (!init)
return DefaultArgumentKind::None;
auto magic = dyn_cast<MagicIdentifierLiteralExpr>(init);
if (!magic)
return DefaultArgumentKind::Normal;
switch (magic->getKind()) {
case MagicIdentifierLiteralExpr::Column:
return DefaultArgumentKind::Column;
case MagicIdentifierLiteralExpr::File:
return DefaultArgumentKind::File;
case MagicIdentifierLiteralExpr::Line:
return DefaultArgumentKind::Line;
case MagicIdentifierLiteralExpr::Function:
return DefaultArgumentKind::Function;
case MagicIdentifierLiteralExpr::DSOHandle:
return DefaultArgumentKind::DSOHandle;
}
llvm_unreachable("Unhandled MagicIdentifierLiteralExpr in switch.");
}
void Parser::DefaultArgumentInfo::setFunctionContext(
DeclContext *DC, ParameterList *paramList){
for (auto context : ParsedContexts) {
context->changeFunction(DC, paramList);
}
}
static ParserStatus parseDefaultArgument(
Parser &P, Parser::DefaultArgumentInfo *defaultArgs, unsigned argIndex,
Expr *&init, Parser::ParameterContextKind paramContext) {
SyntaxParsingContext DefaultArgContext(P.SyntaxContext,
SyntaxKind::InitializerClause);
SourceLoc equalLoc = P.consumeToken(tok::equal);
// Enter a fresh default-argument context with a meaningless parent.
// We'll change the parent to the function later after we've created
// that declaration.
auto initDC = new (P.Context) DefaultArgumentInitializer(P.CurDeclContext,
argIndex);
Parser::ParseFunctionBody initScope(P, initDC);
ParserResult<Expr> initR = P.parseExpr(diag::expected_init_value);
// Record the default-argument context if we're supposed to accept default
// arguments here.
if (defaultArgs) {
defaultArgs->ParsedContexts.push_back(initDC);
}
Diag<> diagID = { DiagID() };
switch (paramContext) {
case Parser::ParameterContextKind::Function:
case Parser::ParameterContextKind::Operator:
case Parser::ParameterContextKind::Initializer:
break;
case Parser::ParameterContextKind::Closure:
diagID = diag::no_default_arg_closure;
break;
case Parser::ParameterContextKind::Subscript:
diagID = diag::no_default_arg_subscript;
break;
case Parser::ParameterContextKind::Curried:
diagID = diag::no_default_arg_curried;
break;
case Parser::ParameterContextKind::EnumElement:
diagID = diag::no_default_arg_enum_elt;
break;
}
assert((diagID.ID != DiagID()) == !defaultArgs &&
"Default arguments specified for an unexpected parameter list kind");
if (diagID.ID != DiagID()) {
auto inFlight = P.diagnose(equalLoc, diagID);
if (initR.isNonNull())
inFlight.fixItRemove(SourceRange(equalLoc, initR.get()->getEndLoc()));
return ParserStatus();
}
defaultArgs->HasDefaultArgument = true;
if (initR.hasCodeCompletion())
return makeParserCodeCompletionStatus();
if (initR.isNull())
return makeParserError();
init = initR.get();
return ParserStatus();
}
/// Determine whether we are at the start of a parameter name when
/// parsing a parameter.
static bool startsParameterName(Parser &parser, bool isClosure) {
// '_' cannot be a type, so it must be a parameter name.
if (parser.Tok.is(tok::kw__))
return true;
// To have a parameter name here, we need a name.
if (!parser.Tok.canBeArgumentLabel())
return false;
// If the next token can be an argument label or is ':', this is a name.
const auto &nextTok = parser.peekToken();
if (nextTok.is(tok::colon) || nextTok.canBeArgumentLabel())
return true;
// The identifier could be a name or it could be a type. In a closure, we
// assume it's a name, because the type can be inferred. Elsewhere, we
// assume it's a type.
return isClosure;
}
ParserStatus
Parser::parseParameterClause(SourceLoc &leftParenLoc,
SmallVectorImpl<ParsedParameter> ¶ms,
SourceLoc &rightParenLoc,
DefaultArgumentInfo *defaultArgs,
ParameterContextKind paramContext) {
assert(params.empty() && leftParenLoc.isInvalid() &&
rightParenLoc.isInvalid() && "Must start with empty state");
SyntaxParsingContext ParamClauseCtx(SyntaxContext, SyntaxKind::ParameterClause);
// Consume the starting '(';
leftParenLoc = consumeToken(tok::l_paren);
// Trivial case: empty parameter list.
if (Tok.is(tok::r_paren)) {
{
SyntaxParsingContext EmptyPLContext(SyntaxContext,
SyntaxKind::FunctionParameterList);
}
rightParenLoc = consumeToken(tok::r_paren);
// Per SE-0155, enum elements may not have empty parameter lists.
if (paramContext == ParameterContextKind::EnumElement) {
decltype(diag::enum_element_empty_arglist) diagnostic;
if (Context.isSwiftVersionAtLeast(5)) {
diagnostic = diag::enum_element_empty_arglist;
} else {
diagnostic = diag::enum_element_empty_arglist_swift4;
}
diagnose(leftParenLoc, diagnostic)
.highlight({leftParenLoc, rightParenLoc});
diagnose(leftParenLoc, diag::enum_element_empty_arglist_delete)
.fixItRemoveChars(leftParenLoc, rightParenLoc);
diagnose(leftParenLoc, diag::enum_element_empty_arglist_add_void)
.fixItInsert(leftParenLoc, "Void");
}
return ParserStatus();
}
// Parse the parameter list.
bool isClosure = paramContext == ParameterContextKind::Closure;
return parseList(tok::r_paren, leftParenLoc, rightParenLoc,
/*AllowSepAfterLast=*/false,
diag::expected_rparen_parameter,
SyntaxKind::FunctionParameterList,
[&]() -> ParserStatus {
ParsedParameter param;
ParserStatus status;
SourceLoc StartLoc = Tok.getLoc();
unsigned defaultArgIndex = defaultArgs ? defaultArgs->NextIndex++ : 0;
// Attributes.
bool FoundCCToken = false;
if (paramContext != ParameterContextKind::EnumElement)
parseDeclAttributeList(param.Attrs, FoundCCToken);
if (FoundCCToken) {
if (CodeCompletion) {
CodeCompletion->completeDeclAttrKeyword(nullptr, isInSILMode(), true);
} else {
status |= makeParserCodeCompletionStatus();
}
}
// ('inout' | 'let' | 'var' | '__shared' | '__owned')?
bool hasSpecifier = false;
while (Tok.isAny(tok::kw_inout, tok::kw_let, tok::kw_var) ||
(Tok.is(tok::identifier) &&
(Tok.getRawText().equals("__shared") ||
Tok.getRawText().equals("__owned")))) {
if (!hasSpecifier) {
if (Tok.is(tok::kw_inout)) {
// This case is handled later when mapping to ParamDecls for
// better fixits.
param.SpecifierKind = VarDecl::Specifier::InOut;
param.SpecifierLoc = consumeToken();
} else if (Tok.is(tok::identifier) &&
Tok.getRawText().equals("__shared")) {
// This case is handled later when mapping to ParamDecls for
// better fixits.
param.SpecifierKind = VarDecl::Specifier::Shared;
param.SpecifierLoc = consumeToken();
} else if (Tok.is(tok::identifier) &&
Tok.getRawText().equals("__owned")) {
// This case is handled later when mapping to ParamDecls for
// better fixits.
param.SpecifierKind = VarDecl::Specifier::Owned;
param.SpecifierLoc = consumeToken();
} else {
diagnose(Tok, diag::parameter_let_var_as_attr, Tok.getText())
.fixItRemove(Tok.getLoc());
consumeToken();
}
hasSpecifier = true;
} else {
// Redundant specifiers are fairly common, recognize, reject, and
// recover from this gracefully.
diagnose(Tok, diag::parameter_specifier_repeated)
.fixItRemove(Tok.getLoc());
consumeToken();
}
}
if (startsParameterName(*this, isClosure)) {
// identifier-or-none for the first name
param.FirstNameLoc = consumeArgumentLabel(param.FirstName);
// identifier-or-none? for the second name
if (Tok.canBeArgumentLabel())
param.SecondNameLoc = consumeArgumentLabel(param.SecondName);
// Operators, closures, and enum elements cannot have API names.
if ((paramContext == ParameterContextKind::Operator ||
paramContext == ParameterContextKind::Closure ||
paramContext == ParameterContextKind::EnumElement) &&
!param.FirstName.empty() &&
param.SecondNameLoc.isValid()) {
enum KeywordArgumentDiagnosticContextKind {
Operator = 0,
Closure = 1,
EnumElement = 2,
} diagContextKind;
switch (paramContext) {
case ParameterContextKind::Operator:
diagContextKind = Operator;
break;
case ParameterContextKind::Closure:
diagContextKind = Closure;
break;
case ParameterContextKind::EnumElement:
diagContextKind = EnumElement;
break;
default:
llvm_unreachable("Unhandled parameter context kind!");
}
diagnose(param.FirstNameLoc, diag::parameter_operator_keyword_argument,
unsigned(diagContextKind))
.fixItRemoveChars(param.FirstNameLoc, param.SecondNameLoc);
param.FirstName = param.SecondName;
param.FirstNameLoc = param.SecondNameLoc;
param.SecondName = Identifier();
param.SecondNameLoc = SourceLoc();
}
// (':' type)?
if (consumeIf(tok::colon)) {
auto type = parseType(diag::expected_parameter_type);
status |= type;
param.Type = type.getPtrOrNull();
// If we didn't parse a type, then we already diagnosed that the type
// was invalid. Remember that.
if (type.isParseError() && !type.hasCodeCompletion())
param.isInvalid = true;
}
} else {
// Otherwise, we have invalid code. Check to see if this looks like a
// type. If so, diagnose it as a common error.
bool isBareType = false;
{
BacktrackingScope backtrack(*this);
isBareType = canParseType() && Tok.isAny(tok::comma, tok::r_paren,
tok::equal);
}
if (isBareType && paramContext == ParameterContextKind::EnumElement) {
auto type = parseType(diag::expected_parameter_type, false);
status |= type;
param.Type = type.getPtrOrNull();
param.FirstName = Identifier();
param.FirstNameLoc = SourceLoc();
param.SecondName = Identifier();
param.SecondNameLoc = SourceLoc();
} else if (isBareType) {
// Otherwise, if this is a bare type, then the user forgot to name the
// parameter, e.g. "func foo(Int) {}"
SourceLoc typeStartLoc = Tok.getLoc();
auto type = parseType(diag::expected_parameter_type, false);
status |= type;
param.Type = type.getPtrOrNull();
// If this is a closure declaration, what is going
// on is most likely argument destructuring, we are going
// to diagnose that after all of the parameters are parsed.
if (param.Type) {
// Mark current parameter as invalid so it is possible
// to diagnose it as destructuring of the closure parameter list.
param.isInvalid = true;
if (!isClosure) {
// Unnamed parameters must be written as "_: Type".
diagnose(typeStartLoc, diag::parameter_unnamed)
.fixItInsert(typeStartLoc, "_: ");
}
}
} else {
// Otherwise, we're not sure what is going on, but this doesn't smell
// like a parameter.
diagnose(Tok, diag::expected_parameter_name);
param.isInvalid = true;
param.FirstNameLoc = Tok.getLoc();
TokReceiver->registerTokenKindChange(param.FirstNameLoc,
tok::identifier);
status.setIsParseError();
}
}
// '...'?
if (Tok.isEllipsis())
param.EllipsisLoc = consumeToken();
// ('=' expr)?
if (Tok.is(tok::equal)) {
SourceLoc EqualLoc = Tok.getLoc();
status |= parseDefaultArgument(*this, defaultArgs, defaultArgIndex,
param.DefaultArg, paramContext);
if (param.EllipsisLoc.isValid() && param.DefaultArg) {
// The range of the complete default argument.
SourceRange defaultArgRange;
if (auto init = param.DefaultArg)
defaultArgRange = SourceRange(param.EllipsisLoc, init->getEndLoc());
diagnose(EqualLoc, diag::parameter_vararg_default)
.highlight(param.EllipsisLoc)
.fixItRemove(defaultArgRange);
param.isInvalid = true;
param.DefaultArg = nullptr;
}
}
// If we haven't made progress, don't add the parameter.
if (Tok.getLoc() == StartLoc) {
// If we took a default argument index for this parameter, but didn't add
// one, then give it back.
if (defaultArgs) defaultArgs->NextIndex--;
return status;
}
params.push_back(param);
return status;
});
}
template <typename T>
static TypeRepr *
validateParameterWithSpecifier(Parser &parser,
Parser::ParsedParameter ¶mInfo,
StringRef specifierName,
bool parsingEnumElt) {
auto type = paramInfo.Type;
auto loc = paramInfo.SpecifierLoc;
// If we're validating an enum element, 'inout' is not allowed
// at all - Sema will catch this for us. In all other contexts, we
// assume the user put 'inout' in the wrong place and offer a fixit.
if (parsingEnumElt) {
return new (parser.Context) T(type, loc);
}
if (isa<SpecifierTypeRepr>(type)) {
parser.diagnose(loc, diag::parameter_specifier_repeated).fixItRemove(loc);
} else {
llvm::SmallString<128> replacement(specifierName);
replacement += " ";
parser
.diagnose(loc, diag::parameter_specifier_as_attr_disallowed,
specifierName)
.fixItRemove(loc)
.fixItInsert(type->getStartLoc(), replacement);
type = new (parser.Context) T(type, loc);
}
return type;
}
/// Map parsed parameters to a ParameterList.
static ParameterList *
mapParsedParameters(Parser &parser,
SourceLoc leftParenLoc,
MutableArrayRef<Parser::ParsedParameter> params,
SourceLoc rightParenLoc,
SmallVectorImpl<Identifier> *argNames,
Parser::ParameterContextKind paramContext) {
auto &ctx = parser.Context;
// Local function to create a pattern for a single parameter.
auto createParam = [&](Parser::ParsedParameter ¶mInfo,
Identifier argName, SourceLoc argNameLoc,
Identifier paramName, SourceLoc paramNameLoc)
-> ParamDecl * {
auto param = new (ctx) ParamDecl(VarDecl::Specifier::Default,
paramInfo.SpecifierLoc,
argNameLoc, argName,
paramNameLoc, paramName,
parser.CurDeclContext);
param->getAttrs() = paramInfo.Attrs;
auto setInvalid = [&]{
if (param->isInvalid())
return;
param->getTypeLoc().setInvalidType(ctx);
param->setInvalid();
};
bool parsingEnumElt
= (paramContext == Parser::ParameterContextKind::EnumElement);
// If we're not parsing an enum case, lack of a SourceLoc for both
// names indicates the parameter is synthetic.
if (!parsingEnumElt && argNameLoc.isInvalid() && paramNameLoc.isInvalid())
param->setImplicit();
// If we diagnosed this parameter as a parse error, propagate to the decl.
if (paramInfo.isInvalid)
setInvalid();
// If a type was provided, create the type for the parameter.
if (auto type = paramInfo.Type) {
// If 'inout' was specified, turn the type into an in-out type.
if (paramInfo.SpecifierKind == VarDecl::Specifier::InOut) {
type = validateParameterWithSpecifier<InOutTypeRepr>(parser, paramInfo,
"inout",
parsingEnumElt);
} else if (paramInfo.SpecifierKind == VarDecl::Specifier::Shared) {
type = validateParameterWithSpecifier<SharedTypeRepr>(parser, paramInfo,
"__shared",
parsingEnumElt);
} else if (paramInfo.SpecifierKind == VarDecl::Specifier::Owned) {
type = validateParameterWithSpecifier<OwnedTypeRepr>(parser, paramInfo,
"__owned",
parsingEnumElt);
}
param->getTypeLoc() = TypeLoc(type);
} else if (paramContext != Parser::ParameterContextKind::Closure) {
// Non-closure parameters require a type.
if (!param->isInvalid())
parser.diagnose(param->getLoc(), diag::missing_parameter_type);
setInvalid();
} else if (paramInfo.SpecifierLoc.isValid()) {
StringRef specifier;
switch (paramInfo.SpecifierKind) {
case VarDecl::Specifier::InOut:
specifier = "'inout'";
break;
case VarDecl::Specifier::Shared:
specifier = "'shared'";
break;
case VarDecl::Specifier::Owned:
specifier = "'owned'";
break;
case VarDecl::Specifier::Let:
case VarDecl::Specifier::Var:
llvm_unreachable("can't have let or var here");
break;
}
parser.diagnose(paramInfo.SpecifierLoc, diag::specifier_must_have_type,
specifier);
paramInfo.SpecifierLoc = SourceLoc();
paramInfo.SpecifierKind = VarDecl::Specifier::Default;
}
return param;
};
// Collect the elements of the tuple patterns for argument and body
// parameters.
SmallVector<ParamDecl*, 4> elements;
SourceLoc ellipsisLoc;
for (auto ¶m : params) {
// Whether the provided name is API by default depends on the parameter
// context.
bool isKeywordArgumentByDefault;
switch (paramContext) {
case Parser::ParameterContextKind::Closure:
case Parser::ParameterContextKind::Subscript:
case Parser::ParameterContextKind::Operator:
isKeywordArgumentByDefault = false;
break;
case Parser::ParameterContextKind::EnumElement:
case Parser::ParameterContextKind::Curried:
case Parser::ParameterContextKind::Initializer:
case Parser::ParameterContextKind::Function:
isKeywordArgumentByDefault = true;
break;
}
// Create the pattern.
ParamDecl *result = nullptr;
Identifier argName;
Identifier paramName;
if (param.SecondNameLoc.isValid()) {
argName = param.FirstName;
paramName = param.SecondName;
// Both names were provided, so pass them in directly.
result = createParam(param, argName, param.FirstNameLoc,
paramName, param.SecondNameLoc);
// If the first and second names are equivalent and non-empty, and we
// would have an argument label by default, complain.
if (isKeywordArgumentByDefault && param.FirstName == param.SecondName
&& !param.FirstName.empty()) {
parser.diagnose(param.FirstNameLoc,
diag::parameter_extraneous_double_up,
param.FirstName)
.fixItRemoveChars(param.FirstNameLoc, param.SecondNameLoc);
}
} else {
if (isKeywordArgumentByDefault)
argName = param.FirstName;
paramName = param.FirstName;
result = createParam(param, argName, SourceLoc(),
param.FirstName, param.FirstNameLoc);
}
// Warn when an unlabeled parameter follows a variadic parameter
if (ellipsisLoc.isValid() && elements.back()->isVariadic() &&
param.FirstName.empty()) {
parser.diagnose(param.FirstNameLoc,
diag::unlabeled_parameter_following_variadic_parameter);
}
// If this parameter had an ellipsis, check whether it's the last parameter.
if (param.EllipsisLoc.isValid()) {
if (ellipsisLoc.isValid()) {
parser.diagnose(param.EllipsisLoc, diag::multiple_parameter_ellipsis)
.highlight(ellipsisLoc)
.fixItRemove(param.EllipsisLoc);
param.EllipsisLoc = SourceLoc();
} else if (!result->getTypeLoc().getTypeRepr()) {
parser.diagnose(param.EllipsisLoc, diag::untyped_pattern_ellipsis)
.highlight(result->getSourceRange());
param.EllipsisLoc = SourceLoc();
} else {
ellipsisLoc = param.EllipsisLoc;
result->setVariadic();
}
}
if (param.DefaultArg) {
assert((paramContext == Parser::ParameterContextKind::Function ||
paramContext == Parser::ParameterContextKind::Operator ||
paramContext == Parser::ParameterContextKind::Initializer ||
paramContext == Parser::ParameterContextKind::EnumElement) &&
"Default arguments are only permitted on the first param clause");
DefaultArgumentKind kind = getDefaultArgKind(param.DefaultArg);
result->setDefaultArgumentKind(kind);
result->setDefaultValue(param.DefaultArg);
}
elements.push_back(result);
if (argNames)
argNames->push_back(argName);
}
return ParameterList::create(ctx, leftParenLoc, elements, rightParenLoc);
}
/// Parse a single parameter-clause.
ParserResult<ParameterList>
Parser::parseSingleParameterClause(ParameterContextKind paramContext,
SmallVectorImpl<Identifier> *namePieces,
DefaultArgumentInfo *defaultArgs) {
if (!Tok.is(tok::l_paren)) {
// If we don't have the leading '(', complain.
Diag<> diagID;
switch (paramContext) {
case ParameterContextKind::Function:
case ParameterContextKind::Operator:
diagID = diag::func_decl_without_paren;
break;
case ParameterContextKind::Subscript:
diagID = diag::expected_lparen_subscript;
break;
case ParameterContextKind::Initializer:
diagID = diag::expected_lparen_initializer;
break;
case ParameterContextKind::EnumElement:
case ParameterContextKind::Closure:
case ParameterContextKind::Curried:
llvm_unreachable("should never be here");
}
{
auto diag = diagnose(Tok, diagID);
if (Tok.isAny(tok::l_brace, tok::arrow, tok::kw_throws, tok::kw_rethrows))
diag.fixItInsertAfter(PreviousLoc, "()");
}
// Create an empty parameter list to recover.
return makeParserErrorResult(
ParameterList::createEmpty(Context, PreviousLoc, PreviousLoc));
}
ParserStatus status;
SmallVector<ParsedParameter, 4> params;
SourceLoc leftParenLoc, rightParenLoc;
// Parse the parameter clause.
status |= parseParameterClause(leftParenLoc, params, rightParenLoc,
defaultArgs, paramContext);
// Turn the parameter clause into argument and body patterns.
auto paramList = mapParsedParameters(*this, leftParenLoc, params,
rightParenLoc, namePieces, paramContext);
return makeParserResult(status, paramList);
}
/// Parse function arguments.
/// func-arguments:
/// curried-arguments | selector-arguments
/// curried-arguments:
/// parameter-clause+
/// selector-arguments:
/// '(' selector-element ')' (identifier '(' selector-element ')')+
/// selector-element:
/// identifier '(' pattern-atom (':' type)? ('=' expr)? ')'
///
ParserStatus
Parser::parseFunctionArguments(SmallVectorImpl<Identifier> &NamePieces,
ParameterList *&BodyParams,
ParameterContextKind paramContext,
DefaultArgumentInfo &DefaultArgs) {
// Parse parameter-clauses.
ParserStatus status;
auto FirstParameterClause
= parseSingleParameterClause(paramContext, &NamePieces, &DefaultArgs);
status |= FirstParameterClause;
BodyParams = FirstParameterClause.get();
SmallVector<ParameterList *, 2> AllParams;
AllParams.push_back(BodyParams);
while (Tok.is(tok::l_paren)) {
auto CurriedParameterClause
= parseSingleParameterClause(ParameterContextKind::Curried);
status |= CurriedParameterClause;
AllParams.push_back(CurriedParameterClause.get());
}
// If the decl uses currying syntax, complain that that syntax has gone away.
if (AllParams.size() > 1) {
SourceRange allPatternsRange(
BodyParams->getStartLoc(),
AllParams.back()->getEndLoc());
auto diag = diagnose(allPatternsRange.Start,
diag::parameter_curry_syntax_removed);
diag.highlight(allPatternsRange);
bool seenArg = false;
for (unsigned i = 0; i < AllParams.size() - 1; i++) {
// Replace ")(" with ", ", so "(x: Int)(y: Int)" becomes
// "(x: Int, y: Int)". But just delete them if they're not actually
// separating any arguments, e.g. in "()(y: Int)".
StringRef replacement(", ");
auto *leftParamList = AllParams[i];
auto *rightParamList = AllParams[i + 1];
if (leftParamList->size() != 0)
seenArg = true;
if (!seenArg || rightParamList->size() == 0)
replacement = "";
diag.fixItReplace(SourceRange(leftParamList->getEndLoc(),
rightParamList->getStartLoc()),
replacement);
}
}
return status;
}
/// Parse a function definition signature.
/// func-signature:
/// func-arguments func-throws? func-signature-result?
/// func-signature-result:
/// '->' type
///
/// Note that this leaves retType as null if unspecified.
ParserStatus
Parser::parseFunctionSignature(Identifier SimpleName,
DeclName &FullName,
ParameterList *&bodyParams,
DefaultArgumentInfo &defaultArgs,
SourceLoc &throwsLoc,
bool &rethrows,
TypeRepr *&retType) {
SyntaxParsingContext SigContext(SyntaxContext, SyntaxKind::FunctionSignature);
SmallVector<Identifier, 4> NamePieces;
ParserStatus Status;
ParameterContextKind paramContext = SimpleName.isOperator() ?
ParameterContextKind::Operator : ParameterContextKind::Function;
Status |= parseFunctionArguments(NamePieces, bodyParams, paramContext,
defaultArgs);
FullName = DeclName(Context, SimpleName, NamePieces);
// Check for the 'throws' keyword.
rethrows = false;
if (Tok.is(tok::kw_throws)) {
throwsLoc = consumeToken();
} else if (Tok.is(tok::kw_rethrows)) {
throwsLoc = consumeToken();
rethrows = true;
} else if (Tok.is(tok::kw_throw)) {
throwsLoc = consumeToken();
diagnose(throwsLoc, diag::throw_in_function_type)
.fixItReplace(throwsLoc, "throws");
}
SourceLoc arrowLoc;
auto diagnoseInvalidThrows = [&]() -> Optional<InFlightDiagnostic> {
if (throwsLoc.isValid())
return None;
if (Tok.is(tok::kw_throws)) {
throwsLoc = consumeToken();
} else if (Tok.is(tok::kw_rethrows)) {
throwsLoc = consumeToken();
rethrows = true;
}
if (!throwsLoc.isValid())
return None;
auto diag = rethrows ? diag::rethrows_in_wrong_position
: diag::throws_in_wrong_position;
return diagnose(Tok, diag);
};
// If there's a trailing arrow, parse the rest as the result type.
if (Tok.isAny(tok::arrow, tok::colon)) {
SyntaxParsingContext ReturnCtx(SyntaxContext, SyntaxKind::ReturnClause);
if (!consumeIf(tok::arrow, arrowLoc)) {
// FixIt ':' to '->'.
diagnose(Tok, diag::func_decl_expected_arrow)
.fixItReplace(Tok.getLoc(), " -> ");
arrowLoc = consumeToken(tok::colon);
}
// Check for 'throws' and 'rethrows' after the arrow, but
// before the type, and correct it.
if (auto diagOpt = diagnoseInvalidThrows()) {
assert(arrowLoc.isValid());
assert(throwsLoc.isValid());
(*diagOpt).fixItExchange(SourceRange(arrowLoc),
SourceRange(throwsLoc));
}
ParserResult<TypeRepr> ResultType =
parseType(diag::expected_type_function_result);
if (ResultType.hasCodeCompletion())
return ResultType;
retType = ResultType.getPtrOrNull();
if (!retType) {
Status.setIsParseError();
return Status;
}
} else {
// Otherwise, we leave retType null.
retType = nullptr;
}
// Check for 'throws' and 'rethrows' after the type and correct it.
if (auto diagOpt = diagnoseInvalidThrows()) {
assert(arrowLoc.isValid());
assert(retType);
SourceLoc typeEndLoc = Lexer::getLocForEndOfToken(SourceMgr,
retType->getEndLoc());
SourceLoc throwsEndLoc = Lexer::getLocForEndOfToken(SourceMgr, throwsLoc);
(*diagOpt).fixItInsert(arrowLoc, rethrows ? "rethrows " : "throws ")
.fixItRemoveChars(typeEndLoc, throwsEndLoc);
}
return Status;
}
/// Parse a pattern with an optional type annotation.
///
/// typed-pattern ::= pattern (':' type)?
///
ParserResult<Pattern> Parser::parseTypedPattern() {
auto result = parsePattern();
// Now parse an optional type annotation.
if (Tok.is(tok::colon)) {
SyntaxParsingContext TypeAnnoCtx(SyntaxContext, SyntaxKind::TypeAnnotation);
SourceLoc colonLoc = consumeToken(tok::colon);
if (result.isNull()) // Recover by creating AnyPattern.
result = makeParserErrorResult(new (Context) AnyPattern(colonLoc));
ParserResult<TypeRepr> Ty = parseType();
if (Ty.hasCodeCompletion())
return makeParserCodeCompletionResult<Pattern>();
if (!Ty.isNull()) {
// Attempt to diagnose initializer calls incorrectly written
// as typed patterns, such as "var x: [Int]()".
// Disable this tentative parse when in code-completion mode, otherwise
// code-completion may enter the delayed-decl state twice.
if (Tok.isFollowingLParen() && !L->isCodeCompletion()) {
BacktrackingScope backtrack(*this);
// Create a local context if needed so we can parse trailing closures.
LocalContext dummyContext;
Optional<ContextChange> contextChange;
if (!CurLocalContext) {
contextChange.emplace(*this, CurDeclContext, &dummyContext);
}
SourceLoc lParenLoc, rParenLoc;
SmallVector<Expr *, 2> args;
SmallVector<Identifier, 2> argLabels;
SmallVector<SourceLoc, 2> argLabelLocs;
Expr *trailingClosure;
ParserStatus status = parseExprList(tok::l_paren, tok::r_paren,
/*isPostfix=*/true,
/*isExprBasic=*/false,
lParenLoc, args, argLabels,
argLabelLocs, rParenLoc,
trailingClosure,
SyntaxKind::Unknown);
if (status.isSuccess()) {
backtrack.cancelBacktrack();
// Suggest replacing ':' with '='
diagnose(lParenLoc, diag::initializer_as_typed_pattern)
.highlight({Ty.get()->getStartLoc(), rParenLoc})
.fixItReplace(colonLoc, " = ");
result.setIsParseError();
}
}
} else {
Ty = makeParserResult(new (Context) ErrorTypeRepr(PreviousLoc));
}
result = makeParserResult(result,
new (Context) TypedPattern(result.get(), Ty.get()));
}
return result;
}
/// Parse a pattern.
/// pattern ::= identifier
/// pattern ::= '_'
/// pattern ::= pattern-tuple
/// pattern ::= 'var' pattern
/// pattern ::= 'let' pattern
///
ParserResult<Pattern> Parser::parsePattern() {
SyntaxParsingContext PatternCtx(SyntaxContext, SyntaxContextKind::Pattern);
bool isLet = (InVarOrLetPattern != IVOLP_InVar);
auto specifier = isLet
? VarDecl::Specifier::Let
: VarDecl::Specifier::Var;
switch (Tok.getKind()) {
case tok::l_paren:
return parsePatternTuple();
case tok::kw__:
// Normally, '_' is invalid in type context for patterns, but they show up
// in interface files as the name for type members that are non-public.
// Treat them as an implicitly synthesized NamedPattern with a nameless
// VarDecl inside.
if (CurDeclContext->isTypeContext() &&
SF.Kind == SourceFileKind::Interface) {
PatternCtx.setCreateSyntax(SyntaxKind::IdentifierPattern);
auto VD = new (Context) VarDecl(
/*IsStatic*/false, specifier, /*IsCaptureList*/false,
consumeToken(tok::kw__), Identifier(), CurDeclContext);
return makeParserResult(new (Context) NamedPattern(VD, /*implicit*/true));
}
PatternCtx.setCreateSyntax(SyntaxKind::WildcardPattern);
return makeParserResult(new (Context) AnyPattern(consumeToken(tok::kw__)));
case tok::identifier: {
PatternCtx.setCreateSyntax(SyntaxKind::IdentifierPattern);
Identifier name;
SourceLoc loc = consumeIdentifier(&name);
if (Tok.isIdentifierOrUnderscore() && !Tok.isContextualDeclKeyword())
diagnoseConsecutiveIDs(name.str(), loc, isLet ? "constant" : "variable");
return makeParserResult(createBindingFromPattern(loc, name, specifier));
}
case tok::code_complete:
if (!CurDeclContext->isTypeContext()) {
// This cannot be an overridden property, so just eat the token. We cannot
// code complete anything here -- we expect an identifier.
consumeToken(tok::code_complete);
}
return nullptr;
case tok::kw_var:
case tok::kw_let: {
PatternCtx.setCreateSyntax(SyntaxKind::ValueBindingPattern);
bool isLet = Tok.is(tok::kw_let);
SourceLoc varLoc = consumeToken();
// 'var' and 'let' patterns shouldn't nest.
if (InVarOrLetPattern == IVOLP_InLet ||
InVarOrLetPattern == IVOLP_InVar)
diagnose(varLoc, diag::var_pattern_in_var, unsigned(isLet));
// 'let' isn't valid inside an implicitly immutable context, but var is.
if (isLet && InVarOrLetPattern == IVOLP_ImplicitlyImmutable)
diagnose(varLoc, diag::let_pattern_in_immutable_context);
// In our recursive parse, remember that we're in a var/let pattern.
llvm::SaveAndRestore<decltype(InVarOrLetPattern)>
T(InVarOrLetPattern, isLet ? IVOLP_InLet : IVOLP_InVar);
ParserResult<Pattern> subPattern = parsePattern();
if (subPattern.hasCodeCompletion())
return makeParserCodeCompletionResult<Pattern>();
if (subPattern.isNull())
return nullptr;
return makeParserResult(new (Context) VarPattern(varLoc, isLet,
subPattern.get()));
}
default:
if (Tok.isKeyword() &&
(peekToken().is(tok::colon) || peekToken().is(tok::equal))) {
diagnose(Tok, diag::keyword_cant_be_identifier, Tok.getText());
diagnose(Tok, diag::backticks_to_escape)
.fixItReplace(Tok.getLoc(), "`" + Tok.getText().str() + "`");
SourceLoc Loc = Tok.getLoc();
consumeToken();
return makeParserErrorResult(new (Context) AnyPattern(Loc));
}
diagnose(Tok, diag::expected_pattern);
return nullptr;
}
}
Pattern *Parser::createBindingFromPattern(SourceLoc loc, Identifier name,
VarDecl::Specifier specifier) {
auto var = new (Context) VarDecl(/*IsStatic*/false, specifier,
/*IsCaptureList*/false, loc, name,
CurDeclContext);