1 // parse.cc -- Go frontend parser.
3 // Copyright 2009 The Go Authors. All rights reserved.
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file.
12 #include "statements.h"
13 #include "expressions.h"
16 // Struct Parse::Enclosing_var_comparison.
18 // Return true if v1 should be considered to be less than v2.
21 Parse::Enclosing_var_comparison::operator()(const Enclosing_var
& v1
,
22 const Enclosing_var
& v2
)
24 if (v1
.var() == v2
.var())
27 const std::string
& n1(v1
.var()->name());
28 const std::string
& n2(v2
.var()->name());
29 int i
= n1
.compare(n2
);
35 // If we get here it means that a single nested function refers to
36 // two different variables defined in enclosing functions, and both
37 // variables have the same name. I think this is impossible.
43 Parse::Parse(Lex
* lex
, Gogo
* gogo
)
45 token_(Token::make_invalid_token(Linemap::unknown_location())),
46 unget_token_(Token::make_invalid_token(Linemap::unknown_location())),
47 unget_token_valid_(false),
48 is_erroneous_function_(false),
51 continue_stack_(NULL
),
58 // Return the current token.
63 if (this->unget_token_valid_
)
64 return &this->unget_token_
;
65 if (this->token_
.is_invalid())
66 this->token_
= this->lex_
->next_token();
70 // Advance to the next token and return it.
73 Parse::advance_token()
75 if (this->unget_token_valid_
)
77 this->unget_token_valid_
= false;
78 if (!this->token_
.is_invalid())
81 this->token_
= this->lex_
->next_token();
85 // Push a token back on the input stream.
88 Parse::unget_token(const Token
& token
)
90 go_assert(!this->unget_token_valid_
);
91 this->unget_token_
= token
;
92 this->unget_token_valid_
= true;
95 // The location of the current token.
100 return this->peek_token()->location();
103 // IdentifierList = identifier { "," identifier } .
106 Parse::identifier_list(Typed_identifier_list
* til
)
108 const Token
* token
= this->peek_token();
111 if (!token
->is_identifier())
113 error_at(this->location(), "expected identifier");
117 this->gogo_
->pack_hidden_name(token
->identifier(),
118 token
->is_identifier_exported());
119 til
->push_back(Typed_identifier(name
, NULL
, token
->location()));
120 token
= this->advance_token();
121 if (!token
->is_op(OPERATOR_COMMA
))
123 token
= this->advance_token();
127 // ExpressionList = Expression { "," Expression } .
129 // If MAY_BE_COMPOSITE_LIT is true, an expression may be a composite
132 // If MAY_BE_SINK is true, the expressions in the list may be "_".
135 Parse::expression_list(Expression
* first
, bool may_be_sink
,
136 bool may_be_composite_lit
)
138 Expression_list
* ret
= new Expression_list();
140 ret
->push_back(first
);
143 ret
->push_back(this->expression(PRECEDENCE_NORMAL
, may_be_sink
,
144 may_be_composite_lit
, NULL
, NULL
));
146 const Token
* token
= this->peek_token();
147 if (!token
->is_op(OPERATOR_COMMA
))
150 // Most expression lists permit a trailing comma.
151 Location location
= token
->location();
152 this->advance_token();
153 if (!this->expression_may_start_here())
155 this->unget_token(Token::make_operator_token(OPERATOR_COMMA
,
162 // QualifiedIdent = [ PackageName "." ] identifier .
163 // PackageName = identifier .
165 // This sets *PNAME to the identifier and sets *PPACKAGE to the
166 // package or NULL if there isn't one. This returns true on success,
167 // false on failure in which case it will have emitted an error
171 Parse::qualified_ident(std::string
* pname
, Named_object
** ppackage
)
173 const Token
* token
= this->peek_token();
174 if (!token
->is_identifier())
176 error_at(this->location(), "expected identifier");
180 std::string name
= token
->identifier();
181 bool is_exported
= token
->is_identifier_exported();
182 name
= this->gogo_
->pack_hidden_name(name
, is_exported
);
184 token
= this->advance_token();
185 if (!token
->is_op(OPERATOR_DOT
))
192 Named_object
* package
= this->gogo_
->lookup(name
, NULL
);
193 if (package
== NULL
|| !package
->is_package())
195 error_at(this->location(), "expected package");
196 // We expect . IDENTIFIER; skip both.
197 if (this->advance_token()->is_identifier())
198 this->advance_token();
202 package
->package_value()->set_used();
204 token
= this->advance_token();
205 if (!token
->is_identifier())
207 error_at(this->location(), "expected identifier");
211 name
= token
->identifier();
215 error_at(this->location(), "invalid use of %<_%>");
216 name
= Gogo::erroneous_name();
219 if (package
->name() == this->gogo_
->package_name())
220 name
= this->gogo_
->pack_hidden_name(name
,
221 token
->is_identifier_exported());
226 this->advance_token();
231 // Type = TypeName | TypeLit | "(" Type ")" .
233 // ArrayType | StructType | PointerType | FunctionType | InterfaceType |
234 // SliceType | MapType | ChannelType .
239 const Token
* token
= this->peek_token();
240 if (token
->is_identifier())
241 return this->type_name(true);
242 else if (token
->is_op(OPERATOR_LSQUARE
))
243 return this->array_type(false);
244 else if (token
->is_keyword(KEYWORD_CHAN
)
245 || token
->is_op(OPERATOR_CHANOP
))
246 return this->channel_type();
247 else if (token
->is_keyword(KEYWORD_INTERFACE
))
248 return this->interface_type();
249 else if (token
->is_keyword(KEYWORD_FUNC
))
251 Location location
= token
->location();
252 this->advance_token();
253 Type
* type
= this->signature(NULL
, location
);
255 return Type::make_error_type();
258 else if (token
->is_keyword(KEYWORD_MAP
))
259 return this->map_type();
260 else if (token
->is_keyword(KEYWORD_STRUCT
))
261 return this->struct_type();
262 else if (token
->is_op(OPERATOR_MULT
))
263 return this->pointer_type();
264 else if (token
->is_op(OPERATOR_LPAREN
))
266 this->advance_token();
267 Type
* ret
= this->type();
268 if (this->peek_token()->is_op(OPERATOR_RPAREN
))
269 this->advance_token();
272 if (!ret
->is_error_type())
273 error_at(this->location(), "expected %<)%>");
279 error_at(token
->location(), "expected type");
280 return Type::make_error_type();
285 Parse::type_may_start_here()
287 const Token
* token
= this->peek_token();
288 return (token
->is_identifier()
289 || token
->is_op(OPERATOR_LSQUARE
)
290 || token
->is_op(OPERATOR_CHANOP
)
291 || token
->is_keyword(KEYWORD_CHAN
)
292 || token
->is_keyword(KEYWORD_INTERFACE
)
293 || token
->is_keyword(KEYWORD_FUNC
)
294 || token
->is_keyword(KEYWORD_MAP
)
295 || token
->is_keyword(KEYWORD_STRUCT
)
296 || token
->is_op(OPERATOR_MULT
)
297 || token
->is_op(OPERATOR_LPAREN
));
300 // TypeName = QualifiedIdent .
302 // If MAY_BE_NIL is true, then an identifier with the value of the
303 // predefined constant nil is accepted, returning the nil type.
306 Parse::type_name(bool issue_error
)
308 Location location
= this->location();
311 Named_object
* package
;
312 if (!this->qualified_ident(&name
, &package
))
313 return Type::make_error_type();
315 Named_object
* named_object
;
317 named_object
= this->gogo_
->lookup(name
, NULL
);
320 named_object
= package
->package_value()->lookup(name
);
321 if (named_object
== NULL
323 && package
->name() != this->gogo_
->package_name())
325 // Check whether the name is there but hidden.
326 std::string s
= ('.' + package
->package_value()->pkgpath()
328 named_object
= package
->package_value()->lookup(s
);
329 if (named_object
!= NULL
)
331 Package
* p
= package
->package_value();
332 const std::string
& packname(p
->package_name());
333 error_at(location
, "invalid reference to hidden type %<%s.%s%>",
334 Gogo::message_name(packname
).c_str(),
335 Gogo::message_name(name
).c_str());
342 if (named_object
== NULL
)
345 named_object
= this->gogo_
->add_unknown_name(name
, location
);
348 const std::string
& packname(package
->package_value()->package_name());
349 error_at(location
, "reference to undefined identifier %<%s.%s%>",
350 Gogo::message_name(packname
).c_str(),
351 Gogo::message_name(name
).c_str());
356 else if (named_object
->is_type())
358 if (!named_object
->type_value()->is_visible())
361 else if (named_object
->is_unknown() || named_object
->is_type_declaration())
369 error_at(location
, "expected type");
370 return Type::make_error_type();
373 if (named_object
->is_type())
374 return named_object
->type_value();
375 else if (named_object
->is_unknown() || named_object
->is_type_declaration())
376 return Type::make_forward_declaration(named_object
);
381 // ArrayType = "[" [ ArrayLength ] "]" ElementType .
382 // ArrayLength = Expression .
383 // ElementType = CompleteType .
386 Parse::array_type(bool may_use_ellipsis
)
388 go_assert(this->peek_token()->is_op(OPERATOR_LSQUARE
));
389 const Token
* token
= this->advance_token();
391 Expression
* length
= NULL
;
392 if (token
->is_op(OPERATOR_RSQUARE
))
393 this->advance_token();
396 if (!token
->is_op(OPERATOR_ELLIPSIS
))
397 length
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
398 else if (may_use_ellipsis
)
400 // An ellipsis is used in composite literals to represent a
401 // fixed array of the size of the number of elements. We
402 // use a length of nil to represent this, and change the
403 // length when parsing the composite literal.
404 length
= Expression::make_nil(this->location());
405 this->advance_token();
409 error_at(this->location(),
410 "use of %<[...]%> outside of array literal");
411 length
= Expression::make_error(this->location());
412 this->advance_token();
414 if (!this->peek_token()->is_op(OPERATOR_RSQUARE
))
416 error_at(this->location(), "expected %<]%>");
417 return Type::make_error_type();
419 this->advance_token();
422 Type
* element_type
= this->type();
424 return Type::make_array_type(element_type
, length
);
427 // MapType = "map" "[" KeyType "]" ValueType .
428 // KeyType = CompleteType .
429 // ValueType = CompleteType .
434 Location location
= this->location();
435 go_assert(this->peek_token()->is_keyword(KEYWORD_MAP
));
436 if (!this->advance_token()->is_op(OPERATOR_LSQUARE
))
438 error_at(this->location(), "expected %<[%>");
439 return Type::make_error_type();
441 this->advance_token();
443 Type
* key_type
= this->type();
445 if (!this->peek_token()->is_op(OPERATOR_RSQUARE
))
447 error_at(this->location(), "expected %<]%>");
448 return Type::make_error_type();
450 this->advance_token();
452 Type
* value_type
= this->type();
454 if (key_type
->is_error_type() || value_type
->is_error_type())
455 return Type::make_error_type();
457 return Type::make_map_type(key_type
, value_type
, location
);
460 // StructType = "struct" "{" { FieldDecl ";" } "}" .
465 go_assert(this->peek_token()->is_keyword(KEYWORD_STRUCT
));
466 Location location
= this->location();
467 if (!this->advance_token()->is_op(OPERATOR_LCURLY
))
469 Location token_loc
= this->location();
470 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
471 && this->advance_token()->is_op(OPERATOR_LCURLY
))
472 error_at(token_loc
, "unexpected semicolon or newline before %<{%>");
475 error_at(this->location(), "expected %<{%>");
476 return Type::make_error_type();
479 this->advance_token();
481 Struct_field_list
* sfl
= new Struct_field_list
;
482 while (!this->peek_token()->is_op(OPERATOR_RCURLY
))
484 this->field_decl(sfl
);
485 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
486 this->advance_token();
487 else if (!this->peek_token()->is_op(OPERATOR_RCURLY
))
489 error_at(this->location(), "expected %<;%> or %<}%> or newline");
490 if (!this->skip_past_error(OPERATOR_RCURLY
))
491 return Type::make_error_type();
494 this->advance_token();
496 for (Struct_field_list::const_iterator pi
= sfl
->begin();
500 if (pi
->type()->is_error_type())
502 for (Struct_field_list::const_iterator pj
= pi
+ 1;
506 if (pi
->field_name() == pj
->field_name()
507 && !Gogo::is_sink_name(pi
->field_name()))
508 error_at(pi
->location(), "duplicate field name %<%s%>",
509 Gogo::message_name(pi
->field_name()).c_str());
513 return Type::make_struct_type(sfl
, location
);
516 // FieldDecl = (IdentifierList CompleteType | TypeName) [ Tag ] .
517 // Tag = string_lit .
520 Parse::field_decl(Struct_field_list
* sfl
)
522 const Token
* token
= this->peek_token();
523 Location location
= token
->location();
525 bool is_anonymous_pointer
;
526 if (token
->is_op(OPERATOR_MULT
))
529 is_anonymous_pointer
= true;
531 else if (token
->is_identifier())
533 std::string id
= token
->identifier();
534 bool is_id_exported
= token
->is_identifier_exported();
535 Location id_location
= token
->location();
536 token
= this->advance_token();
537 is_anonymous
= (token
->is_op(OPERATOR_SEMICOLON
)
538 || token
->is_op(OPERATOR_RCURLY
)
539 || token
->is_op(OPERATOR_DOT
)
540 || token
->is_string());
541 is_anonymous_pointer
= false;
542 this->unget_token(Token::make_identifier_token(id
, is_id_exported
,
547 error_at(this->location(), "expected field name");
548 this->gogo_
->mark_locals_used();
549 while (!token
->is_op(OPERATOR_SEMICOLON
)
550 && !token
->is_op(OPERATOR_RCURLY
)
552 token
= this->advance_token();
558 if (is_anonymous_pointer
)
560 this->advance_token();
561 if (!this->peek_token()->is_identifier())
563 error_at(this->location(), "expected field name");
564 this->gogo_
->mark_locals_used();
565 while (!token
->is_op(OPERATOR_SEMICOLON
)
566 && !token
->is_op(OPERATOR_RCURLY
)
568 token
= this->advance_token();
572 Type
* type
= this->type_name(true);
575 if (this->peek_token()->is_string())
577 tag
= this->peek_token()->string_value();
578 this->advance_token();
581 if (!type
->is_error_type())
583 if (is_anonymous_pointer
)
584 type
= Type::make_pointer_type(type
);
585 sfl
->push_back(Struct_field(Typed_identifier("", type
, location
)));
587 sfl
->back().set_tag(tag
);
592 Typed_identifier_list til
;
595 token
= this->peek_token();
596 if (!token
->is_identifier())
598 error_at(this->location(), "expected identifier");
602 this->gogo_
->pack_hidden_name(token
->identifier(),
603 token
->is_identifier_exported());
604 til
.push_back(Typed_identifier(name
, NULL
, token
->location()));
605 if (!this->advance_token()->is_op(OPERATOR_COMMA
))
607 this->advance_token();
610 Type
* type
= this->type();
613 if (this->peek_token()->is_string())
615 tag
= this->peek_token()->string_value();
616 this->advance_token();
619 for (Typed_identifier_list::iterator p
= til
.begin();
624 sfl
->push_back(Struct_field(*p
));
626 sfl
->back().set_tag(tag
);
631 // PointerType = "*" Type .
634 Parse::pointer_type()
636 go_assert(this->peek_token()->is_op(OPERATOR_MULT
));
637 this->advance_token();
638 Type
* type
= this->type();
639 if (type
->is_error_type())
641 return Type::make_pointer_type(type
);
644 // ChannelType = Channel | SendChannel | RecvChannel .
645 // Channel = "chan" ElementType .
646 // SendChannel = "chan" "<-" ElementType .
647 // RecvChannel = "<-" "chan" ElementType .
650 Parse::channel_type()
652 const Token
* token
= this->peek_token();
655 if (token
->is_op(OPERATOR_CHANOP
))
657 if (!this->advance_token()->is_keyword(KEYWORD_CHAN
))
659 error_at(this->location(), "expected %<chan%>");
660 return Type::make_error_type();
663 this->advance_token();
667 go_assert(token
->is_keyword(KEYWORD_CHAN
));
668 if (this->advance_token()->is_op(OPERATOR_CHANOP
))
671 this->advance_token();
675 // Better error messages for the common error of omitting the
676 // channel element type.
677 if (!this->type_may_start_here())
679 token
= this->peek_token();
680 if (token
->is_op(OPERATOR_RCURLY
))
681 error_at(this->location(), "unexpected %<}%> in channel type");
682 else if (token
->is_op(OPERATOR_RPAREN
))
683 error_at(this->location(), "unexpected %<)%> in channel type");
684 else if (token
->is_op(OPERATOR_COMMA
))
685 error_at(this->location(), "unexpected comma in channel type");
687 error_at(this->location(), "expected channel element type");
688 return Type::make_error_type();
691 Type
* element_type
= this->type();
692 return Type::make_channel_type(send
, receive
, element_type
);
695 // Give an error for a duplicate parameter or receiver name.
698 Parse::check_signature_names(const Typed_identifier_list
* params
,
701 for (Typed_identifier_list::const_iterator p
= params
->begin();
705 if (p
->name().empty() || Gogo::is_sink_name(p
->name()))
707 std::pair
<std::string
, const Typed_identifier
*> val
=
708 std::make_pair(p
->name(), &*p
);
709 std::pair
<Parse::Names::iterator
, bool> ins
= names
->insert(val
);
712 error_at(p
->location(), "redefinition of %qs",
713 Gogo::message_name(p
->name()).c_str());
714 inform(ins
.first
->second
->location(),
715 "previous definition of %qs was here",
716 Gogo::message_name(p
->name()).c_str());
721 // Signature = Parameters [ Result ] .
723 // RECEIVER is the receiver if there is one, or NULL. LOCATION is the
724 // location of the start of the type.
726 // This returns NULL on a parse error.
729 Parse::signature(Typed_identifier
* receiver
, Location location
)
731 bool is_varargs
= false;
732 Typed_identifier_list
* params
;
733 bool params_ok
= this->parameters(¶ms
, &is_varargs
);
735 Typed_identifier_list
* results
= NULL
;
736 if (this->peek_token()->is_op(OPERATOR_LPAREN
)
737 || this->type_may_start_here())
739 if (!this->result(&results
))
747 if (receiver
!= NULL
)
748 names
[receiver
->name()] = receiver
;
750 this->check_signature_names(params
, &names
);
752 this->check_signature_names(results
, &names
);
754 Function_type
* ret
= Type::make_function_type(receiver
, params
, results
,
757 ret
->set_is_varargs();
761 // Parameters = "(" [ ParameterList [ "," ] ] ")" .
763 // This returns false on a parse error.
766 Parse::parameters(Typed_identifier_list
** pparams
, bool* is_varargs
)
770 if (!this->peek_token()->is_op(OPERATOR_LPAREN
))
772 error_at(this->location(), "expected %<(%>");
776 Typed_identifier_list
* params
= NULL
;
777 bool saw_error
= false;
779 const Token
* token
= this->advance_token();
780 if (!token
->is_op(OPERATOR_RPAREN
))
782 params
= this->parameter_list(is_varargs
);
785 token
= this->peek_token();
788 // The optional trailing comma is picked up in parameter_list.
790 if (!token
->is_op(OPERATOR_RPAREN
))
791 error_at(this->location(), "expected %<)%>");
793 this->advance_token();
802 // ParameterList = ParameterDecl { "," ParameterDecl } .
804 // This sets *IS_VARARGS if the list ends with an ellipsis.
805 // IS_VARARGS will be NULL if varargs are not permitted.
807 // We pick up an optional trailing comma.
809 // This returns NULL if some error is seen.
811 Typed_identifier_list
*
812 Parse::parameter_list(bool* is_varargs
)
814 Location location
= this->location();
815 Typed_identifier_list
* ret
= new Typed_identifier_list();
817 bool saw_error
= false;
819 // If we see an identifier and then a comma, then we don't know
820 // whether we are looking at a list of identifiers followed by a
821 // type, or a list of types given by name. We have to do an
822 // arbitrary lookahead to figure it out.
824 bool parameters_have_names
;
825 const Token
* token
= this->peek_token();
826 if (!token
->is_identifier())
828 // This must be a type which starts with something like '*'.
829 parameters_have_names
= false;
833 std::string name
= token
->identifier();
834 bool is_exported
= token
->is_identifier_exported();
835 Location location
= token
->location();
836 token
= this->advance_token();
837 if (!token
->is_op(OPERATOR_COMMA
))
839 if (token
->is_op(OPERATOR_DOT
))
841 // This is a qualified identifier, which must turn out
843 parameters_have_names
= false;
845 else if (token
->is_op(OPERATOR_RPAREN
))
847 // A single identifier followed by a parenthesis must be
849 parameters_have_names
= false;
853 // An identifier followed by something other than a
854 // comma or a dot or a right parenthesis must be a
855 // parameter name followed by a type.
856 parameters_have_names
= true;
859 this->unget_token(Token::make_identifier_token(name
, is_exported
,
864 // An identifier followed by a comma may be the first in a
865 // list of parameter names followed by a type, or it may be
866 // the first in a list of types without parameter names. To
867 // find out we gather as many identifiers separated by
869 std::string id_name
= this->gogo_
->pack_hidden_name(name
,
871 ret
->push_back(Typed_identifier(id_name
, NULL
, location
));
872 bool just_saw_comma
= true;
873 while (this->advance_token()->is_identifier())
875 name
= this->peek_token()->identifier();
876 is_exported
= this->peek_token()->is_identifier_exported();
877 location
= this->peek_token()->location();
878 id_name
= this->gogo_
->pack_hidden_name(name
, is_exported
);
879 ret
->push_back(Typed_identifier(id_name
, NULL
, location
));
880 if (!this->advance_token()->is_op(OPERATOR_COMMA
))
882 just_saw_comma
= false;
889 // We saw ID1 "," ID2 "," followed by something which
890 // was not an identifier. We must be seeing the start
891 // of a type, and ID1 and ID2 must be types, and the
892 // parameters don't have names.
893 parameters_have_names
= false;
895 else if (this->peek_token()->is_op(OPERATOR_RPAREN
))
897 // We saw ID1 "," ID2 ")". ID1 and ID2 must be types,
898 // and the parameters don't have names.
899 parameters_have_names
= false;
901 else if (this->peek_token()->is_op(OPERATOR_DOT
))
903 // We saw ID1 "," ID2 ".". ID2 must be a package name,
904 // ID1 must be a type, and the parameters don't have
906 parameters_have_names
= false;
907 this->unget_token(Token::make_identifier_token(name
, is_exported
,
910 just_saw_comma
= true;
914 // We saw ID1 "," ID2 followed by something other than
915 // ",", ".", or ")". We must be looking at the start of
916 // a type, and ID1 and ID2 must be parameter names.
917 parameters_have_names
= true;
920 if (parameters_have_names
)
922 go_assert(!just_saw_comma
);
923 // We have just seen ID1, ID2 xxx.
925 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS
))
929 error_at(this->location(), "%<...%> only permits one name");
931 this->advance_token();
934 for (size_t i
= 0; i
< ret
->size(); ++i
)
935 ret
->set_type(i
, type
);
936 if (!this->peek_token()->is_op(OPERATOR_COMMA
))
937 return saw_error
? NULL
: ret
;
938 if (this->advance_token()->is_op(OPERATOR_RPAREN
))
939 return saw_error
? NULL
: ret
;
943 Typed_identifier_list
* tret
= new Typed_identifier_list();
944 for (Typed_identifier_list::const_iterator p
= ret
->begin();
948 Named_object
* no
= this->gogo_
->lookup(p
->name(), NULL
);
951 no
= this->gogo_
->add_unknown_name(p
->name(),
955 type
= no
->type_value();
956 else if (no
->is_unknown() || no
->is_type_declaration())
957 type
= Type::make_forward_declaration(no
);
960 error_at(p
->location(), "expected %<%s%> to be a type",
961 Gogo::message_name(p
->name()).c_str());
963 type
= Type::make_error_type();
965 tret
->push_back(Typed_identifier("", type
, p
->location()));
970 || this->peek_token()->is_op(OPERATOR_RPAREN
))
971 return saw_error
? NULL
: ret
;
976 bool mix_error
= false;
977 this->parameter_decl(parameters_have_names
, ret
, is_varargs
, &mix_error
,
979 while (this->peek_token()->is_op(OPERATOR_COMMA
))
981 if (this->advance_token()->is_op(OPERATOR_RPAREN
))
983 if (is_varargs
!= NULL
&& *is_varargs
)
985 error_at(this->location(), "%<...%> must be last parameter");
988 this->parameter_decl(parameters_have_names
, ret
, is_varargs
, &mix_error
,
993 error_at(location
, "invalid named/anonymous mix");
1004 // ParameterDecl = [ IdentifierList ] [ "..." ] Type .
1007 Parse::parameter_decl(bool parameters_have_names
,
1008 Typed_identifier_list
* til
,
1013 if (!parameters_have_names
)
1016 Location location
= this->location();
1017 if (!this->peek_token()->is_identifier())
1019 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS
))
1020 type
= this->type();
1023 if (is_varargs
== NULL
)
1024 error_at(this->location(), "invalid use of %<...%>");
1027 this->advance_token();
1028 if (is_varargs
== NULL
1029 && this->peek_token()->is_op(OPERATOR_RPAREN
))
1030 type
= Type::make_error_type();
1033 Type
* element_type
= this->type();
1034 type
= Type::make_array_type(element_type
, NULL
);
1040 type
= this->type_name(false);
1041 if (type
->is_error_type()
1042 || (!this->peek_token()->is_op(OPERATOR_COMMA
)
1043 && !this->peek_token()->is_op(OPERATOR_RPAREN
)))
1046 while (!this->peek_token()->is_op(OPERATOR_COMMA
)
1047 && !this->peek_token()->is_op(OPERATOR_RPAREN
))
1048 this->advance_token();
1051 if (!type
->is_error_type())
1052 til
->push_back(Typed_identifier("", type
, location
));
1058 size_t orig_count
= til
->size();
1059 if (this->peek_token()->is_identifier())
1060 this->identifier_list(til
);
1063 size_t new_count
= til
->size();
1066 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS
))
1067 type
= this->type();
1070 if (is_varargs
== NULL
)
1072 error_at(this->location(), "invalid use of %<...%>");
1075 else if (new_count
> orig_count
+ 1)
1077 error_at(this->location(), "%<...%> only permits one name");
1082 this->advance_token();
1083 Type
* element_type
= this->type();
1084 type
= Type::make_array_type(element_type
, NULL
);
1086 for (size_t i
= orig_count
; i
< new_count
; ++i
)
1087 til
->set_type(i
, type
);
1091 // Result = Parameters | Type .
1093 // This returns false on a parse error.
1096 Parse::result(Typed_identifier_list
** presults
)
1098 if (this->peek_token()->is_op(OPERATOR_LPAREN
))
1099 return this->parameters(presults
, NULL
);
1102 Location location
= this->location();
1103 Type
* type
= this->type();
1104 if (type
->is_error_type())
1109 Typed_identifier_list
* til
= new Typed_identifier_list();
1110 til
->push_back(Typed_identifier("", type
, location
));
1116 // Block = "{" [ StatementList ] "}" .
1118 // Returns the location of the closing brace.
1123 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
1125 Location loc
= this->location();
1126 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1127 && this->advance_token()->is_op(OPERATOR_LCURLY
))
1128 error_at(loc
, "unexpected semicolon or newline before %<{%>");
1131 error_at(this->location(), "expected %<{%>");
1132 return Linemap::unknown_location();
1136 const Token
* token
= this->advance_token();
1138 if (!token
->is_op(OPERATOR_RCURLY
))
1140 this->statement_list();
1141 token
= this->peek_token();
1142 if (!token
->is_op(OPERATOR_RCURLY
))
1144 if (!token
->is_eof() || !saw_errors())
1145 error_at(this->location(), "expected %<}%>");
1147 this->gogo_
->mark_locals_used();
1149 // Skip ahead to the end of the block, in hopes of avoiding
1150 // lots of meaningless errors.
1151 Location ret
= token
->location();
1153 while (!token
->is_eof())
1155 if (token
->is_op(OPERATOR_LCURLY
))
1157 else if (token
->is_op(OPERATOR_RCURLY
))
1162 this->advance_token();
1166 token
= this->advance_token();
1167 ret
= token
->location();
1173 Location ret
= token
->location();
1174 this->advance_token();
1178 // InterfaceType = "interface" "{" [ MethodSpecList ] "}" .
1179 // MethodSpecList = MethodSpec { ";" MethodSpec } [ ";" ] .
1182 Parse::interface_type()
1184 go_assert(this->peek_token()->is_keyword(KEYWORD_INTERFACE
));
1185 Location location
= this->location();
1187 if (!this->advance_token()->is_op(OPERATOR_LCURLY
))
1189 Location token_loc
= this->location();
1190 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1191 && this->advance_token()->is_op(OPERATOR_LCURLY
))
1192 error_at(token_loc
, "unexpected semicolon or newline before %<{%>");
1195 error_at(this->location(), "expected %<{%>");
1196 return Type::make_error_type();
1199 this->advance_token();
1201 Typed_identifier_list
* methods
= new Typed_identifier_list();
1202 if (!this->peek_token()->is_op(OPERATOR_RCURLY
))
1204 this->method_spec(methods
);
1205 while (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
1207 if (this->advance_token()->is_op(OPERATOR_RCURLY
))
1209 this->method_spec(methods
);
1211 if (!this->peek_token()->is_op(OPERATOR_RCURLY
))
1213 error_at(this->location(), "expected %<}%>");
1214 while (!this->advance_token()->is_op(OPERATOR_RCURLY
))
1216 if (this->peek_token()->is_eof())
1217 return Type::make_error_type();
1221 this->advance_token();
1223 if (methods
->empty())
1229 Interface_type
* ret
= Type::make_interface_type(methods
, location
);
1230 this->gogo_
->record_interface_type(ret
);
1234 // MethodSpec = MethodName Signature | InterfaceTypeName .
1235 // MethodName = identifier .
1236 // InterfaceTypeName = TypeName .
1239 Parse::method_spec(Typed_identifier_list
* methods
)
1241 const Token
* token
= this->peek_token();
1242 if (!token
->is_identifier())
1244 error_at(this->location(), "expected identifier");
1248 std::string name
= token
->identifier();
1249 bool is_exported
= token
->is_identifier_exported();
1250 Location location
= token
->location();
1252 if (this->advance_token()->is_op(OPERATOR_LPAREN
))
1254 // This is a MethodName.
1255 name
= this->gogo_
->pack_hidden_name(name
, is_exported
);
1256 Type
* type
= this->signature(NULL
, location
);
1259 methods
->push_back(Typed_identifier(name
, type
, location
));
1263 this->unget_token(Token::make_identifier_token(name
, is_exported
,
1265 Type
* type
= this->type_name(false);
1266 if (type
->is_error_type()
1267 || (!this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1268 && !this->peek_token()->is_op(OPERATOR_RCURLY
)))
1270 if (this->peek_token()->is_op(OPERATOR_COMMA
))
1271 error_at(this->location(),
1272 "name list not allowed in interface type");
1274 error_at(location
, "expected signature or type name");
1275 this->gogo_
->mark_locals_used();
1276 token
= this->peek_token();
1277 while (!token
->is_eof()
1278 && !token
->is_op(OPERATOR_SEMICOLON
)
1279 && !token
->is_op(OPERATOR_RCURLY
))
1280 token
= this->advance_token();
1283 // This must be an interface type, but we can't check that now.
1284 // We check it and pull out the methods in
1285 // Interface_type::do_verify.
1286 methods
->push_back(Typed_identifier("", type
, location
));
1290 // Declaration = ConstDecl | TypeDecl | VarDecl | FunctionDecl | MethodDecl .
1293 Parse::declaration()
1295 const Token
* token
= this->peek_token();
1297 bool saw_nointerface
= this->lex_
->get_and_clear_nointerface();
1298 if (saw_nointerface
&& !token
->is_keyword(KEYWORD_FUNC
))
1299 warning_at(token
->location(), 0,
1300 "ignoring magic //go:nointerface comment before non-method");
1302 if (token
->is_keyword(KEYWORD_CONST
))
1304 else if (token
->is_keyword(KEYWORD_TYPE
))
1306 else if (token
->is_keyword(KEYWORD_VAR
))
1308 else if (token
->is_keyword(KEYWORD_FUNC
))
1309 this->function_decl(saw_nointerface
);
1312 error_at(this->location(), "expected declaration");
1313 this->advance_token();
1318 Parse::declaration_may_start_here()
1320 const Token
* token
= this->peek_token();
1321 return (token
->is_keyword(KEYWORD_CONST
)
1322 || token
->is_keyword(KEYWORD_TYPE
)
1323 || token
->is_keyword(KEYWORD_VAR
)
1324 || token
->is_keyword(KEYWORD_FUNC
));
1327 // Decl<P> = P | "(" [ List<P> ] ")" .
1330 Parse::decl(void (Parse::*pfn
)(void*), void* varg
)
1332 if (this->peek_token()->is_eof())
1335 error_at(this->location(), "unexpected end of file");
1339 if (!this->peek_token()->is_op(OPERATOR_LPAREN
))
1343 if (!this->advance_token()->is_op(OPERATOR_RPAREN
))
1345 this->list(pfn
, varg
, true);
1346 if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
1348 error_at(this->location(), "missing %<)%>");
1349 while (!this->advance_token()->is_op(OPERATOR_RPAREN
))
1351 if (this->peek_token()->is_eof())
1356 this->advance_token();
1360 // List<P> = P { ";" P } [ ";" ] .
1362 // In order to pick up the trailing semicolon we need to know what
1363 // might follow. This is either a '}' or a ')'.
1366 Parse::list(void (Parse::*pfn
)(void*), void* varg
, bool follow_is_paren
)
1369 Operator follow
= follow_is_paren
? OPERATOR_RPAREN
: OPERATOR_RCURLY
;
1370 while (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1371 || this->peek_token()->is_op(OPERATOR_COMMA
))
1373 if (this->peek_token()->is_op(OPERATOR_COMMA
))
1374 error_at(this->location(), "unexpected comma");
1375 if (this->advance_token()->is_op(follow
))
1381 // ConstDecl = "const" ( ConstSpec | "(" { ConstSpec ";" } ")" ) .
1386 go_assert(this->peek_token()->is_keyword(KEYWORD_CONST
));
1387 this->advance_token();
1390 Type
* last_type
= NULL
;
1391 Expression_list
* last_expr_list
= NULL
;
1393 if (!this->peek_token()->is_op(OPERATOR_LPAREN
))
1394 this->const_spec(&last_type
, &last_expr_list
);
1397 this->advance_token();
1398 while (!this->peek_token()->is_op(OPERATOR_RPAREN
))
1400 this->const_spec(&last_type
, &last_expr_list
);
1401 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
1402 this->advance_token();
1403 else if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
1405 error_at(this->location(), "expected %<;%> or %<)%> or newline");
1406 if (!this->skip_past_error(OPERATOR_RPAREN
))
1410 this->advance_token();
1413 if (last_expr_list
!= NULL
)
1414 delete last_expr_list
;
1417 // ConstSpec = IdentifierList [ [ CompleteType ] "=" ExpressionList ] .
1420 Parse::const_spec(Type
** last_type
, Expression_list
** last_expr_list
)
1422 Typed_identifier_list til
;
1423 this->identifier_list(&til
);
1426 if (this->type_may_start_here())
1428 type
= this->type();
1430 *last_expr_list
= NULL
;
1433 Expression_list
*expr_list
;
1434 if (!this->peek_token()->is_op(OPERATOR_EQ
))
1436 if (*last_expr_list
== NULL
)
1438 error_at(this->location(), "expected %<=%>");
1442 expr_list
= new Expression_list
;
1443 for (Expression_list::const_iterator p
= (*last_expr_list
)->begin();
1444 p
!= (*last_expr_list
)->end();
1446 expr_list
->push_back((*p
)->copy());
1450 this->advance_token();
1451 expr_list
= this->expression_list(NULL
, false, true);
1453 if (*last_expr_list
!= NULL
)
1454 delete *last_expr_list
;
1455 *last_expr_list
= expr_list
;
1458 Expression_list::const_iterator pe
= expr_list
->begin();
1459 for (Typed_identifier_list::iterator pi
= til
.begin();
1463 if (pe
== expr_list
->end())
1465 error_at(this->location(), "not enough initializers");
1471 if (!Gogo::is_sink_name(pi
->name()))
1472 this->gogo_
->add_constant(*pi
, *pe
, this->iota_value());
1477 snprintf(buf
, sizeof buf
, ".$sinkconst%d", count
);
1479 Typed_identifier
ti(std::string(buf
), type
, pi
->location());
1480 Named_object
* no
= this->gogo_
->add_constant(ti
, *pe
, this->iota_value());
1481 no
->const_value()->set_is_sink();
1484 if (pe
!= expr_list
->end())
1485 error_at(this->location(), "too many initializers");
1487 this->increment_iota();
1492 // TypeDecl = "type" Decl<TypeSpec> .
1497 go_assert(this->peek_token()->is_keyword(KEYWORD_TYPE
));
1498 this->advance_token();
1499 this->decl(&Parse::type_spec
, NULL
);
1502 // TypeSpec = identifier Type .
1505 Parse::type_spec(void*)
1507 const Token
* token
= this->peek_token();
1508 if (!token
->is_identifier())
1510 error_at(this->location(), "expected identifier");
1513 std::string name
= token
->identifier();
1514 bool is_exported
= token
->is_identifier_exported();
1515 Location location
= token
->location();
1516 token
= this->advance_token();
1518 // The scope of the type name starts at the point where the
1519 // identifier appears in the source code. We implement this by
1520 // declaring the type before we read the type definition.
1521 Named_object
* named_type
= NULL
;
1524 name
= this->gogo_
->pack_hidden_name(name
, is_exported
);
1525 named_type
= this->gogo_
->declare_type(name
, location
);
1529 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON
))
1530 type
= this->type();
1533 error_at(this->location(),
1534 "unexpected semicolon or newline in type declaration");
1535 type
= Type::make_error_type();
1536 this->advance_token();
1539 if (type
->is_error_type())
1541 this->gogo_
->mark_locals_used();
1542 while (!this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1543 && !this->peek_token()->is_eof())
1544 this->advance_token();
1549 if (named_type
->is_type_declaration())
1551 Type
* ftype
= type
->forwarded();
1552 if (ftype
->forward_declaration_type() != NULL
1553 && (ftype
->forward_declaration_type()->named_object()
1556 error_at(location
, "invalid recursive type");
1557 type
= Type::make_error_type();
1560 this->gogo_
->define_type(named_type
,
1561 Type::make_named_type(named_type
, type
,
1563 go_assert(named_type
->package() == NULL
);
1567 // This will probably give a redefinition error.
1568 this->gogo_
->add_type(name
, type
, location
);
1573 // VarDecl = "var" Decl<VarSpec> .
1578 go_assert(this->peek_token()->is_keyword(KEYWORD_VAR
));
1579 this->advance_token();
1580 this->decl(&Parse::var_spec
, NULL
);
1583 // VarSpec = IdentifierList
1584 // ( CompleteType [ "=" ExpressionList ] | "=" ExpressionList ) .
1587 Parse::var_spec(void*)
1589 // Get the variable names.
1590 Typed_identifier_list til
;
1591 this->identifier_list(&til
);
1593 Location location
= this->location();
1596 Expression_list
* init
= NULL
;
1597 if (!this->peek_token()->is_op(OPERATOR_EQ
))
1599 type
= this->type();
1600 if (type
->is_error_type())
1602 this->gogo_
->mark_locals_used();
1603 while (!this->peek_token()->is_op(OPERATOR_EQ
)
1604 && !this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1605 && !this->peek_token()->is_eof())
1606 this->advance_token();
1608 if (this->peek_token()->is_op(OPERATOR_EQ
))
1610 this->advance_token();
1611 init
= this->expression_list(NULL
, false, true);
1616 this->advance_token();
1617 init
= this->expression_list(NULL
, false, true);
1620 this->init_vars(&til
, type
, init
, false, location
);
1626 // Create variables. TIL is a list of variable names. If TYPE is not
1627 // NULL, it is the type of all the variables. If INIT is not NULL, it
1628 // is an initializer list for the variables.
1631 Parse::init_vars(const Typed_identifier_list
* til
, Type
* type
,
1632 Expression_list
* init
, bool is_coloneq
,
1635 // Check for an initialization which can yield multiple values.
1636 if (init
!= NULL
&& init
->size() == 1 && til
->size() > 1)
1638 if (this->init_vars_from_call(til
, type
, *init
->begin(), is_coloneq
,
1641 if (this->init_vars_from_map(til
, type
, *init
->begin(), is_coloneq
,
1644 if (this->init_vars_from_receive(til
, type
, *init
->begin(), is_coloneq
,
1647 if (this->init_vars_from_type_guard(til
, type
, *init
->begin(),
1648 is_coloneq
, location
))
1652 if (init
!= NULL
&& init
->size() != til
->size())
1654 if (init
->empty() || !init
->front()->is_error_expression())
1655 error_at(location
, "wrong number of initializations");
1658 type
= Type::make_error_type();
1661 // Note that INIT was already parsed with the old name bindings, so
1662 // we don't have to worry that it will accidentally refer to the
1663 // newly declared variables. But we do have to worry about a mix of
1664 // newly declared variables and old variables if the old variables
1665 // appear in the initializations.
1667 Expression_list::const_iterator pexpr
;
1669 pexpr
= init
->begin();
1670 bool any_new
= false;
1671 Expression_list
* vars
= new Expression_list();
1672 Expression_list
* vals
= new Expression_list();
1673 for (Typed_identifier_list::const_iterator p
= til
->begin();
1678 go_assert(pexpr
!= init
->end());
1679 this->init_var(*p
, type
, init
== NULL
? NULL
: *pexpr
, is_coloneq
,
1680 false, &any_new
, vars
, vals
);
1685 go_assert(pexpr
== init
->end());
1686 if (is_coloneq
&& !any_new
)
1687 error_at(location
, "variables redeclared but no variable is new");
1688 this->finish_init_vars(vars
, vals
, location
);
1691 // See if we need to initialize a list of variables from a function
1692 // call. This returns true if we have set up the variables and the
1696 Parse::init_vars_from_call(const Typed_identifier_list
* vars
, Type
* type
,
1697 Expression
* expr
, bool is_coloneq
,
1700 Call_expression
* call
= expr
->call_expression();
1704 // This is a function call. We can't check here whether it returns
1705 // the right number of values, but it might. Declare the variables,
1706 // and then assign the results of the call to them.
1708 call
->set_expected_result_count(vars
->size());
1710 Named_object
* first_var
= NULL
;
1711 unsigned int index
= 0;
1712 bool any_new
= false;
1713 Expression_list
* ivars
= new Expression_list();
1714 Expression_list
* ivals
= new Expression_list();
1715 for (Typed_identifier_list::const_iterator pv
= vars
->begin();
1719 Expression
* init
= Expression::make_call_result(call
, index
);
1720 Named_object
* no
= this->init_var(*pv
, type
, init
, is_coloneq
, false,
1721 &any_new
, ivars
, ivals
);
1723 if (this->gogo_
->in_global_scope() && no
->is_variable())
1725 if (first_var
== NULL
)
1729 // The subsequent vars have an implicit dependency on
1730 // the first one, so that everything gets initialized in
1731 // the right order and so that we detect cycles
1733 this->gogo_
->record_var_depends_on(no
->var_value(), first_var
);
1738 if (is_coloneq
&& !any_new
)
1739 error_at(location
, "variables redeclared but no variable is new");
1741 this->finish_init_vars(ivars
, ivals
, location
);
1746 // See if we need to initialize a pair of values from a map index
1747 // expression. This returns true if we have set up the variables and
1748 // the initialization.
1751 Parse::init_vars_from_map(const Typed_identifier_list
* vars
, Type
* type
,
1752 Expression
* expr
, bool is_coloneq
,
1755 Index_expression
* index
= expr
->index_expression();
1758 if (vars
->size() != 2)
1761 // This is an index which is being assigned to two variables. It
1762 // must be a map index. Declare the variables, and then assign the
1763 // results of the map index.
1764 bool any_new
= false;
1765 Typed_identifier_list::const_iterator p
= vars
->begin();
1766 Expression
* init
= type
== NULL
? index
: NULL
;
1767 Named_object
* val_no
= this->init_var(*p
, type
, init
, is_coloneq
,
1768 type
== NULL
, &any_new
, NULL
, NULL
);
1769 if (type
== NULL
&& any_new
&& val_no
->is_variable())
1770 val_no
->var_value()->set_type_from_init_tuple();
1771 Expression
* val_var
= Expression::make_var_reference(val_no
, location
);
1774 Type
* var_type
= type
;
1775 if (var_type
== NULL
)
1776 var_type
= Type::lookup_bool_type();
1777 Named_object
* no
= this->init_var(*p
, var_type
, NULL
, is_coloneq
, false,
1778 &any_new
, NULL
, NULL
);
1779 Expression
* present_var
= Expression::make_var_reference(no
, location
);
1781 if (is_coloneq
&& !any_new
)
1782 error_at(location
, "variables redeclared but no variable is new");
1784 Statement
* s
= Statement::make_tuple_map_assignment(val_var
, present_var
,
1787 if (!this->gogo_
->in_global_scope())
1788 this->gogo_
->add_statement(s
);
1789 else if (!val_no
->is_sink())
1791 if (val_no
->is_variable())
1792 val_no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1794 else if (!no
->is_sink())
1796 if (no
->is_variable())
1797 no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1801 // Execute the map index expression just so that we can fail if
1803 Named_object
* dummy
= this->create_dummy_global(Type::lookup_bool_type(),
1805 dummy
->var_value()->add_preinit_statement(this->gogo_
, s
);
1811 // See if we need to initialize a pair of values from a receive
1812 // expression. This returns true if we have set up the variables and
1813 // the initialization.
1816 Parse::init_vars_from_receive(const Typed_identifier_list
* vars
, Type
* type
,
1817 Expression
* expr
, bool is_coloneq
,
1820 Receive_expression
* receive
= expr
->receive_expression();
1821 if (receive
== NULL
)
1823 if (vars
->size() != 2)
1826 // This is a receive expression which is being assigned to two
1827 // variables. Declare the variables, and then assign the results of
1829 bool any_new
= false;
1830 Typed_identifier_list::const_iterator p
= vars
->begin();
1831 Expression
* init
= type
== NULL
? receive
: NULL
;
1832 Named_object
* val_no
= this->init_var(*p
, type
, init
, is_coloneq
,
1833 type
== NULL
, &any_new
, NULL
, NULL
);
1834 if (type
== NULL
&& any_new
&& val_no
->is_variable())
1835 val_no
->var_value()->set_type_from_init_tuple();
1836 Expression
* val_var
= Expression::make_var_reference(val_no
, location
);
1839 Type
* var_type
= type
;
1840 if (var_type
== NULL
)
1841 var_type
= Type::lookup_bool_type();
1842 Named_object
* no
= this->init_var(*p
, var_type
, NULL
, is_coloneq
, false,
1843 &any_new
, NULL
, NULL
);
1844 Expression
* received_var
= Expression::make_var_reference(no
, location
);
1846 if (is_coloneq
&& !any_new
)
1847 error_at(location
, "variables redeclared but no variable is new");
1849 Statement
* s
= Statement::make_tuple_receive_assignment(val_var
,
1854 if (!this->gogo_
->in_global_scope())
1855 this->gogo_
->add_statement(s
);
1856 else if (!val_no
->is_sink())
1858 if (val_no
->is_variable())
1859 val_no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1861 else if (!no
->is_sink())
1863 if (no
->is_variable())
1864 no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1868 Named_object
* dummy
= this->create_dummy_global(Type::lookup_bool_type(),
1870 dummy
->var_value()->add_preinit_statement(this->gogo_
, s
);
1876 // See if we need to initialize a pair of values from a type guard
1877 // expression. This returns true if we have set up the variables and
1878 // the initialization.
1881 Parse::init_vars_from_type_guard(const Typed_identifier_list
* vars
,
1882 Type
* type
, Expression
* expr
,
1883 bool is_coloneq
, Location location
)
1885 Type_guard_expression
* type_guard
= expr
->type_guard_expression();
1886 if (type_guard
== NULL
)
1888 if (vars
->size() != 2)
1891 // This is a type guard expression which is being assigned to two
1892 // variables. Declare the variables, and then assign the results of
1894 bool any_new
= false;
1895 Typed_identifier_list::const_iterator p
= vars
->begin();
1896 Type
* var_type
= type
;
1897 if (var_type
== NULL
)
1898 var_type
= type_guard
->type();
1899 Named_object
* val_no
= this->init_var(*p
, var_type
, NULL
, is_coloneq
, false,
1900 &any_new
, NULL
, NULL
);
1901 Expression
* val_var
= Expression::make_var_reference(val_no
, location
);
1905 if (var_type
== NULL
)
1906 var_type
= Type::lookup_bool_type();
1907 Named_object
* no
= this->init_var(*p
, var_type
, NULL
, is_coloneq
, false,
1908 &any_new
, NULL
, NULL
);
1909 Expression
* ok_var
= Expression::make_var_reference(no
, location
);
1911 Expression
* texpr
= type_guard
->expr();
1912 Type
* t
= type_guard
->type();
1913 Statement
* s
= Statement::make_tuple_type_guard_assignment(val_var
, ok_var
,
1917 if (is_coloneq
&& !any_new
)
1918 error_at(location
, "variables redeclared but no variable is new");
1920 if (!this->gogo_
->in_global_scope())
1921 this->gogo_
->add_statement(s
);
1922 else if (!val_no
->is_sink())
1924 if (val_no
->is_variable())
1925 val_no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1927 else if (!no
->is_sink())
1929 if (no
->is_variable())
1930 no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1934 Named_object
* dummy
= this->create_dummy_global(type
, NULL
, location
);
1935 dummy
->var_value()->add_preinit_statement(this->gogo_
, s
);
1941 // Create a single variable. If IS_COLONEQ is true, we permit
1942 // redeclarations in the same block, and we set *IS_NEW when we find a
1943 // new variable which is not a redeclaration.
1946 Parse::init_var(const Typed_identifier
& tid
, Type
* type
, Expression
* init
,
1947 bool is_coloneq
, bool type_from_init
, bool* is_new
,
1948 Expression_list
* vars
, Expression_list
* vals
)
1950 Location location
= tid
.location();
1952 if (Gogo::is_sink_name(tid
.name()))
1954 if (!type_from_init
&& init
!= NULL
)
1956 if (this->gogo_
->in_global_scope())
1957 return this->create_dummy_global(type
, init
, location
);
1960 // Create a dummy variable so that we will check whether the
1961 // initializer can be assigned to the type.
1962 Variable
* var
= new Variable(type
, init
, false, false, false,
1967 snprintf(buf
, sizeof buf
, "sink$%d", count
);
1969 return this->gogo_
->add_variable(buf
, var
);
1973 this->gogo_
->add_type_to_verify(type
);
1974 return this->gogo_
->add_sink();
1979 Named_object
* no
= this->gogo_
->lookup_in_block(tid
.name());
1981 && (no
->is_variable() || no
->is_result_variable()))
1983 // INIT may be NULL even when IS_COLONEQ is true for cases
1984 // like v, ok := x.(int).
1985 if (!type_from_init
&& init
!= NULL
)
1987 go_assert(vars
!= NULL
&& vals
!= NULL
);
1988 vars
->push_back(Expression::make_var_reference(no
, location
));
1989 vals
->push_back(init
);
1995 Variable
* var
= new Variable(type
, init
, this->gogo_
->in_global_scope(),
1996 false, false, location
);
1997 Named_object
* no
= this->gogo_
->add_variable(tid
.name(), var
);
1998 if (!no
->is_variable())
2000 // The name is already defined, so we just gave an error.
2001 return this->gogo_
->add_sink();
2006 // Create a dummy global variable to force an initializer to be run in
2007 // the right place. This is used when a sink variable is initialized
2011 Parse::create_dummy_global(Type
* type
, Expression
* init
,
2014 if (type
== NULL
&& init
== NULL
)
2015 type
= Type::lookup_bool_type();
2016 Variable
* var
= new Variable(type
, init
, true, false, false, location
);
2019 snprintf(buf
, sizeof buf
, "_.%d", count
);
2021 return this->gogo_
->add_variable(buf
, var
);
2024 // Finish the variable initialization by executing any assignments to
2025 // existing variables when using :=. These must be done as a tuple
2026 // assignment in case of something like n, a, b := 1, b, a.
2029 Parse::finish_init_vars(Expression_list
* vars
, Expression_list
* vals
,
2037 else if (vars
->size() == 1)
2039 go_assert(!this->gogo_
->in_global_scope());
2040 this->gogo_
->add_statement(Statement::make_assignment(vars
->front(),
2048 go_assert(!this->gogo_
->in_global_scope());
2049 this->gogo_
->add_statement(Statement::make_tuple_assignment(vars
, vals
,
2054 // SimpleVarDecl = identifier ":=" Expression .
2056 // We've already seen the identifier.
2058 // FIXME: We also have to implement
2059 // IdentifierList ":=" ExpressionList
2060 // In order to support both "a, b := 1, 0" and "a, b = 1, 0" we accept
2061 // tuple assignments here as well.
2063 // If MAY_BE_COMPOSITE_LIT is true, the expression on the right hand
2064 // side may be a composite literal.
2066 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
2069 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
2070 // guard (var := expr.("type") using the literal keyword "type").
2073 Parse::simple_var_decl_or_assignment(const std::string
& name
,
2075 bool may_be_composite_lit
,
2076 Range_clause
* p_range_clause
,
2077 Type_switch
* p_type_switch
)
2079 Typed_identifier_list til
;
2080 til
.push_back(Typed_identifier(name
, NULL
, location
));
2082 // We've seen one identifier. If we see a comma now, this could be
2084 if (this->peek_token()->is_op(OPERATOR_COMMA
))
2086 go_assert(p_type_switch
== NULL
);
2089 const Token
* token
= this->advance_token();
2090 if (!token
->is_identifier())
2093 std::string id
= token
->identifier();
2094 bool is_id_exported
= token
->is_identifier_exported();
2095 Location id_location
= token
->location();
2097 token
= this->advance_token();
2098 if (!token
->is_op(OPERATOR_COMMA
))
2100 if (token
->is_op(OPERATOR_COLONEQ
))
2102 id
= this->gogo_
->pack_hidden_name(id
, is_id_exported
);
2103 til
.push_back(Typed_identifier(id
, NULL
, location
));
2106 this->unget_token(Token::make_identifier_token(id
,
2112 id
= this->gogo_
->pack_hidden_name(id
, is_id_exported
);
2113 til
.push_back(Typed_identifier(id
, NULL
, location
));
2116 // We have a comma separated list of identifiers in TIL. If the
2117 // next token is COLONEQ, then this is a simple var decl, and we
2118 // have the complete list of identifiers. If the next token is
2119 // not COLONEQ, then the only valid parse is a tuple assignment.
2120 // The list of identifiers we have so far is really a list of
2121 // expressions. There are more expressions following.
2123 if (!this->peek_token()->is_op(OPERATOR_COLONEQ
))
2125 Expression_list
* exprs
= new Expression_list
;
2126 for (Typed_identifier_list::const_iterator p
= til
.begin();
2129 exprs
->push_back(this->id_to_expression(p
->name(), p
->location(),
2132 Expression_list
* more_exprs
=
2133 this->expression_list(NULL
, true, may_be_composite_lit
);
2134 for (Expression_list::const_iterator p
= more_exprs
->begin();
2135 p
!= more_exprs
->end();
2137 exprs
->push_back(*p
);
2140 this->tuple_assignment(exprs
, may_be_composite_lit
, p_range_clause
);
2145 go_assert(this->peek_token()->is_op(OPERATOR_COLONEQ
));
2146 const Token
* token
= this->advance_token();
2148 if (p_range_clause
!= NULL
&& token
->is_keyword(KEYWORD_RANGE
))
2150 this->range_clause_decl(&til
, p_range_clause
);
2154 Expression_list
* init
;
2155 if (p_type_switch
== NULL
)
2156 init
= this->expression_list(NULL
, false, may_be_composite_lit
);
2159 bool is_type_switch
= false;
2160 Expression
* expr
= this->expression(PRECEDENCE_NORMAL
, false,
2161 may_be_composite_lit
,
2162 &is_type_switch
, NULL
);
2165 p_type_switch
->found
= true;
2166 p_type_switch
->name
= name
;
2167 p_type_switch
->location
= location
;
2168 p_type_switch
->expr
= expr
;
2172 if (!this->peek_token()->is_op(OPERATOR_COMMA
))
2174 init
= new Expression_list();
2175 init
->push_back(expr
);
2179 this->advance_token();
2180 init
= this->expression_list(expr
, false, may_be_composite_lit
);
2184 this->init_vars(&til
, NULL
, init
, true, location
);
2187 // FunctionDecl = "func" identifier Signature [ Block ] .
2188 // MethodDecl = "func" Receiver identifier Signature [ Block ] .
2190 // Deprecated gcc extension:
2191 // FunctionDecl = "func" identifier Signature
2192 // __asm__ "(" string_lit ")" .
2193 // This extension means a function whose real name is the identifier
2194 // inside the asm. This extension will be removed at some future
2195 // date. It has been replaced with //extern comments.
2197 // SAW_NOINTERFACE is true if we saw a magic //go:nointerface comment,
2198 // which means that we omit the method from the type descriptor.
2201 Parse::function_decl(bool saw_nointerface
)
2203 go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC
));
2204 Location location
= this->location();
2205 std::string extern_name
= this->lex_
->extern_name();
2206 const Token
* token
= this->advance_token();
2208 Typed_identifier
* rec
= NULL
;
2209 if (token
->is_op(OPERATOR_LPAREN
))
2211 rec
= this->receiver();
2212 token
= this->peek_token();
2214 else if (saw_nointerface
)
2216 warning_at(location
, 0,
2217 "ignoring magic //go:nointerface comment before non-method");
2218 saw_nointerface
= false;
2221 if (!token
->is_identifier())
2223 error_at(this->location(), "expected function name");
2228 this->gogo_
->pack_hidden_name(token
->identifier(),
2229 token
->is_identifier_exported());
2231 this->advance_token();
2233 Function_type
* fntype
= this->signature(rec
, this->location());
2235 Named_object
* named_object
= NULL
;
2237 if (this->peek_token()->is_keyword(KEYWORD_ASM
))
2239 if (!this->advance_token()->is_op(OPERATOR_LPAREN
))
2241 error_at(this->location(), "expected %<(%>");
2244 token
= this->advance_token();
2245 if (!token
->is_string())
2247 error_at(this->location(), "expected string");
2250 std::string asm_name
= token
->string_value();
2251 if (!this->advance_token()->is_op(OPERATOR_RPAREN
))
2253 error_at(this->location(), "expected %<)%>");
2256 this->advance_token();
2257 if (!Gogo::is_sink_name(name
))
2259 named_object
= this->gogo_
->declare_function(name
, fntype
, location
);
2260 if (named_object
->is_function_declaration())
2261 named_object
->func_declaration_value()->set_asm_name(asm_name
);
2265 // Check for the easy error of a newline before the opening brace.
2266 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
2268 Location semi_loc
= this->location();
2269 if (this->advance_token()->is_op(OPERATOR_LCURLY
))
2270 error_at(this->location(),
2271 "unexpected semicolon or newline before %<{%>");
2273 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON
,
2277 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
2279 if (named_object
== NULL
&& !Gogo::is_sink_name(name
))
2282 this->gogo_
->add_erroneous_name(name
);
2285 named_object
= this->gogo_
->declare_function(name
, fntype
,
2287 if (!extern_name
.empty()
2288 && named_object
->is_function_declaration())
2290 Function_declaration
* fd
=
2291 named_object
->func_declaration_value();
2292 fd
->set_asm_name(extern_name
);
2297 if (saw_nointerface
)
2298 warning_at(location
, 0,
2299 ("ignoring magic //go:nointerface comment "
2300 "before declaration"));
2304 bool hold_is_erroneous_function
= this->is_erroneous_function_
;
2307 fntype
= Type::make_function_type(NULL
, NULL
, NULL
, location
);
2308 this->is_erroneous_function_
= true;
2309 if (!Gogo::is_sink_name(name
))
2310 this->gogo_
->add_erroneous_name(name
);
2311 name
= this->gogo_
->pack_hidden_name("_", false);
2313 named_object
= this->gogo_
->start_function(name
, fntype
, true, location
);
2314 Location end_loc
= this->block();
2315 this->gogo_
->finish_function(end_loc
);
2317 && !this->is_erroneous_function_
2318 && named_object
->is_function())
2319 named_object
->func_value()->set_nointerface();
2320 this->is_erroneous_function_
= hold_is_erroneous_function
;
2324 // Receiver = Parameters .
2329 Location location
= this->location();
2330 Typed_identifier_list
* til
;
2331 if (!this->parameters(&til
, NULL
))
2333 else if (til
== NULL
|| til
->empty())
2335 error_at(location
, "method has no receiver");
2338 else if (til
->size() > 1)
2340 error_at(location
, "method has multiple receivers");
2344 return &til
->front();
2347 // Operand = Literal | QualifiedIdent | MethodExpr | "(" Expression ")" .
2348 // Literal = BasicLit | CompositeLit | FunctionLit .
2349 // BasicLit = int_lit | float_lit | imaginary_lit | char_lit | string_lit .
2351 // If MAY_BE_SINK is true, this operand may be "_".
2353 // If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
2354 // if the entire expression is in parentheses.
2357 Parse::operand(bool may_be_sink
, bool* is_parenthesized
)
2359 const Token
* token
= this->peek_token();
2361 switch (token
->classification())
2363 case Token::TOKEN_IDENTIFIER
:
2365 Location location
= token
->location();
2366 std::string id
= token
->identifier();
2367 bool is_exported
= token
->is_identifier_exported();
2368 std::string packed
= this->gogo_
->pack_hidden_name(id
, is_exported
);
2370 Named_object
* in_function
;
2371 Named_object
* named_object
= this->gogo_
->lookup(packed
, &in_function
);
2373 Package
* package
= NULL
;
2374 if (named_object
!= NULL
&& named_object
->is_package())
2376 if (!this->advance_token()->is_op(OPERATOR_DOT
)
2377 || !this->advance_token()->is_identifier())
2379 error_at(location
, "unexpected reference to package");
2380 return Expression::make_error(location
);
2382 package
= named_object
->package_value();
2383 package
->set_used();
2384 id
= this->peek_token()->identifier();
2385 is_exported
= this->peek_token()->is_identifier_exported();
2386 packed
= this->gogo_
->pack_hidden_name(id
, is_exported
);
2387 named_object
= package
->lookup(packed
);
2388 location
= this->location();
2389 go_assert(in_function
== NULL
);
2392 this->advance_token();
2394 if (named_object
!= NULL
2395 && named_object
->is_type()
2396 && !named_object
->type_value()->is_visible())
2398 go_assert(package
!= NULL
);
2399 error_at(location
, "invalid reference to hidden type %<%s.%s%>",
2400 Gogo::message_name(package
->package_name()).c_str(),
2401 Gogo::message_name(id
).c_str());
2402 return Expression::make_error(location
);
2406 if (named_object
== NULL
)
2408 if (package
!= NULL
)
2410 std::string n1
= Gogo::message_name(package
->package_name());
2411 std::string n2
= Gogo::message_name(id
);
2414 ("invalid reference to unexported identifier "
2416 n1
.c_str(), n2
.c_str());
2419 "reference to undefined identifier %<%s.%s%>",
2420 n1
.c_str(), n2
.c_str());
2421 return Expression::make_error(location
);
2424 named_object
= this->gogo_
->add_unknown_name(packed
, location
);
2427 if (in_function
!= NULL
2428 && in_function
!= this->gogo_
->current_function()
2429 && (named_object
->is_variable()
2430 || named_object
->is_result_variable()))
2431 return this->enclosing_var_reference(in_function
, named_object
,
2434 switch (named_object
->classification())
2436 case Named_object::NAMED_OBJECT_CONST
:
2437 return Expression::make_const_reference(named_object
, location
);
2438 case Named_object::NAMED_OBJECT_TYPE
:
2439 return Expression::make_type(named_object
->type_value(), location
);
2440 case Named_object::NAMED_OBJECT_TYPE_DECLARATION
:
2442 Type
* t
= Type::make_forward_declaration(named_object
);
2443 return Expression::make_type(t
, location
);
2445 case Named_object::NAMED_OBJECT_VAR
:
2446 case Named_object::NAMED_OBJECT_RESULT_VAR
:
2447 // Any left-hand-side can be a sink, so if this can not be
2448 // a sink, then it must be a use of the variable.
2450 this->mark_var_used(named_object
);
2451 return Expression::make_var_reference(named_object
, location
);
2452 case Named_object::NAMED_OBJECT_SINK
:
2454 return Expression::make_sink(location
);
2457 error_at(location
, "cannot use _ as value");
2458 return Expression::make_error(location
);
2460 case Named_object::NAMED_OBJECT_FUNC
:
2461 case Named_object::NAMED_OBJECT_FUNC_DECLARATION
:
2462 return Expression::make_func_reference(named_object
, NULL
,
2464 case Named_object::NAMED_OBJECT_UNKNOWN
:
2466 Unknown_expression
* ue
=
2467 Expression::make_unknown_reference(named_object
, location
);
2468 if (this->is_erroneous_function_
)
2469 ue
->set_no_error_message();
2472 case Named_object::NAMED_OBJECT_ERRONEOUS
:
2473 return Expression::make_error(location
);
2480 case Token::TOKEN_STRING
:
2481 ret
= Expression::make_string(token
->string_value(), token
->location());
2482 this->advance_token();
2485 case Token::TOKEN_CHARACTER
:
2486 ret
= Expression::make_character(token
->character_value(), NULL
,
2488 this->advance_token();
2491 case Token::TOKEN_INTEGER
:
2492 ret
= Expression::make_integer(token
->integer_value(), NULL
,
2494 this->advance_token();
2497 case Token::TOKEN_FLOAT
:
2498 ret
= Expression::make_float(token
->float_value(), NULL
,
2500 this->advance_token();
2503 case Token::TOKEN_IMAGINARY
:
2506 mpfr_init_set_ui(zero
, 0, GMP_RNDN
);
2507 ret
= Expression::make_complex(&zero
, token
->imaginary_value(),
2508 NULL
, token
->location());
2510 this->advance_token();
2514 case Token::TOKEN_KEYWORD
:
2515 switch (token
->keyword())
2518 return this->function_lit();
2520 case KEYWORD_INTERFACE
:
2522 case KEYWORD_STRUCT
:
2524 Location location
= token
->location();
2525 return Expression::make_type(this->type(), location
);
2532 case Token::TOKEN_OPERATOR
:
2533 if (token
->is_op(OPERATOR_LPAREN
))
2535 this->advance_token();
2536 ret
= this->expression(PRECEDENCE_NORMAL
, may_be_sink
, true, NULL
,
2538 if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
2539 error_at(this->location(), "missing %<)%>");
2541 this->advance_token();
2542 if (is_parenthesized
!= NULL
)
2543 *is_parenthesized
= true;
2546 else if (token
->is_op(OPERATOR_LSQUARE
))
2548 // Here we call array_type directly, as this is the only
2549 // case where an ellipsis is permitted for an array type.
2550 Location location
= token
->location();
2551 return Expression::make_type(this->array_type(true), location
);
2559 error_at(this->location(), "expected operand");
2560 return Expression::make_error(this->location());
2563 // Handle a reference to a variable in an enclosing function. We add
2564 // it to a list of such variables. We return a reference to a field
2565 // in a struct which will be passed on the static chain when calling
2566 // the current function.
2569 Parse::enclosing_var_reference(Named_object
* in_function
, Named_object
* var
,
2572 go_assert(var
->is_variable() || var
->is_result_variable());
2574 this->mark_var_used(var
);
2576 Named_object
* this_function
= this->gogo_
->current_function();
2577 Named_object
* closure
= this_function
->func_value()->closure_var();
2579 // The last argument to the Enclosing_var constructor is the index
2580 // of this variable in the closure. We add 1 to the current number
2581 // of enclosed variables, because the first field in the closure
2582 // points to the function code.
2583 Enclosing_var
ev(var
, in_function
, this->enclosing_vars_
.size() + 1);
2584 std::pair
<Enclosing_vars::iterator
, bool> ins
=
2585 this->enclosing_vars_
.insert(ev
);
2588 // This is a variable we have not seen before. Add a new field
2589 // to the closure type.
2590 this_function
->func_value()->add_closure_field(var
, location
);
2593 Expression
* closure_ref
= Expression::make_var_reference(closure
,
2595 closure_ref
= Expression::make_unary(OPERATOR_MULT
, closure_ref
, location
);
2597 // The closure structure holds pointers to the variables, so we need
2598 // to introduce an indirection.
2599 Expression
* e
= Expression::make_field_reference(closure_ref
,
2602 e
= Expression::make_unary(OPERATOR_MULT
, e
, location
);
2606 // CompositeLit = LiteralType LiteralValue .
2607 // LiteralType = StructType | ArrayType | "[" "..." "]" ElementType |
2608 // SliceType | MapType | TypeName .
2609 // LiteralValue = "{" [ ElementList [ "," ] ] "}" .
2610 // ElementList = Element { "," Element } .
2611 // Element = [ Key ":" ] Value .
2612 // Key = FieldName | ElementIndex .
2613 // FieldName = identifier .
2614 // ElementIndex = Expression .
2615 // Value = Expression | LiteralValue .
2617 // We have already seen the type if there is one, and we are now
2618 // looking at the LiteralValue. The case "[" "..." "]" ElementType
2619 // will be seen here as an array type whose length is "nil". The
2620 // DEPTH parameter is non-zero if this is an embedded composite
2621 // literal and the type was omitted. It gives the number of steps up
2622 // to the type which was provided. E.g., in [][]int{{1}} it will be
2623 // 1. In [][][]int{{{1}}} it will be 2.
2626 Parse::composite_lit(Type
* type
, int depth
, Location location
)
2628 go_assert(this->peek_token()->is_op(OPERATOR_LCURLY
));
2629 this->advance_token();
2631 if (this->peek_token()->is_op(OPERATOR_RCURLY
))
2633 this->advance_token();
2634 return Expression::make_composite_literal(type
, depth
, false, NULL
,
2638 bool has_keys
= false;
2639 bool all_are_names
= true;
2640 Expression_list
* vals
= new Expression_list
;
2644 bool is_type_omitted
= false;
2645 bool is_name
= false;
2647 const Token
* token
= this->peek_token();
2649 if (token
->is_identifier())
2651 std::string identifier
= token
->identifier();
2652 bool is_exported
= token
->is_identifier_exported();
2653 Location location
= token
->location();
2655 if (this->advance_token()->is_op(OPERATOR_COLON
))
2657 // This may be a field name. We don't know for sure--it
2658 // could also be an expression for an array index. We
2659 // don't want to parse it as an expression because may
2660 // trigger various errors, e.g., if this identifier
2661 // happens to be the name of a package.
2662 Gogo
* gogo
= this->gogo_
;
2663 val
= this->id_to_expression(gogo
->pack_hidden_name(identifier
,
2670 this->unget_token(Token::make_identifier_token(identifier
,
2673 val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
,
2677 else if (!token
->is_op(OPERATOR_LCURLY
))
2678 val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
2681 // This must be a composite literal inside another composite
2682 // literal, with the type omitted for the inner one.
2683 val
= this->composite_lit(type
, depth
+ 1, token
->location());
2684 is_type_omitted
= true;
2687 token
= this->peek_token();
2688 if (!token
->is_op(OPERATOR_COLON
))
2691 vals
->push_back(NULL
);
2696 if (is_type_omitted
&& !val
->is_error_expression())
2698 error_at(this->location(), "unexpected %<:%>");
2699 val
= Expression::make_error(this->location());
2702 this->advance_token();
2704 if (!has_keys
&& !vals
->empty())
2706 Expression_list
* newvals
= new Expression_list
;
2707 for (Expression_list::const_iterator p
= vals
->begin();
2711 newvals
->push_back(NULL
);
2712 newvals
->push_back(*p
);
2719 if (val
->unknown_expression() != NULL
)
2720 val
->unknown_expression()->set_is_composite_literal_key();
2722 vals
->push_back(val
);
2724 if (!token
->is_op(OPERATOR_LCURLY
))
2725 val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
2728 // This must be a composite literal inside another
2729 // composite literal, with the type omitted for the
2731 val
= this->composite_lit(type
, depth
+ 1, token
->location());
2734 token
= this->peek_token();
2737 vals
->push_back(val
);
2740 all_are_names
= false;
2742 if (token
->is_op(OPERATOR_COMMA
))
2744 if (this->advance_token()->is_op(OPERATOR_RCURLY
))
2746 this->advance_token();
2750 else if (token
->is_op(OPERATOR_RCURLY
))
2752 this->advance_token();
2757 if (token
->is_op(OPERATOR_SEMICOLON
))
2758 error_at(this->location(),
2759 "need trailing comma before newline in composite literal");
2761 error_at(this->location(), "expected %<,%> or %<}%>");
2763 this->gogo_
->mark_locals_used();
2765 while (!token
->is_eof()
2766 && (depth
> 0 || !token
->is_op(OPERATOR_RCURLY
)))
2768 if (token
->is_op(OPERATOR_LCURLY
))
2770 else if (token
->is_op(OPERATOR_RCURLY
))
2772 token
= this->advance_token();
2774 if (token
->is_op(OPERATOR_RCURLY
))
2775 this->advance_token();
2777 return Expression::make_error(location
);
2781 return Expression::make_composite_literal(type
, depth
, has_keys
, vals
,
2782 all_are_names
, location
);
2785 // FunctionLit = "func" Signature Block .
2788 Parse::function_lit()
2790 Location location
= this->location();
2791 go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC
));
2792 this->advance_token();
2794 Enclosing_vars hold_enclosing_vars
;
2795 hold_enclosing_vars
.swap(this->enclosing_vars_
);
2797 Function_type
* type
= this->signature(NULL
, location
);
2798 bool fntype_is_error
= false;
2801 type
= Type::make_function_type(NULL
, NULL
, NULL
, location
);
2802 fntype_is_error
= true;
2805 // For a function literal, the next token must be a '{'. If we
2806 // don't see that, then we may have a type expression.
2807 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
2809 hold_enclosing_vars
.swap(this->enclosing_vars_
);
2810 return Expression::make_type(type
, location
);
2813 bool hold_is_erroneous_function
= this->is_erroneous_function_
;
2814 if (fntype_is_error
)
2815 this->is_erroneous_function_
= true;
2817 Bc_stack
* hold_break_stack
= this->break_stack_
;
2818 Bc_stack
* hold_continue_stack
= this->continue_stack_
;
2819 this->break_stack_
= NULL
;
2820 this->continue_stack_
= NULL
;
2822 Named_object
* no
= this->gogo_
->start_function("", type
, true, location
);
2824 Location end_loc
= this->block();
2826 this->gogo_
->finish_function(end_loc
);
2828 if (this->break_stack_
!= NULL
)
2829 delete this->break_stack_
;
2830 if (this->continue_stack_
!= NULL
)
2831 delete this->continue_stack_
;
2832 this->break_stack_
= hold_break_stack
;
2833 this->continue_stack_
= hold_continue_stack
;
2835 this->is_erroneous_function_
= hold_is_erroneous_function
;
2837 hold_enclosing_vars
.swap(this->enclosing_vars_
);
2839 Expression
* closure
= this->create_closure(no
, &hold_enclosing_vars
,
2842 return Expression::make_func_reference(no
, closure
, location
);
2845 // Create a closure for the nested function FUNCTION. This is based
2846 // on ENCLOSING_VARS, which is a list of all variables defined in
2847 // enclosing functions and referenced from FUNCTION. A closure is the
2848 // address of a struct which point to the real function code and
2849 // contains the addresses of all the referenced variables. This
2850 // returns NULL if no closure is required.
2853 Parse::create_closure(Named_object
* function
, Enclosing_vars
* enclosing_vars
,
2856 if (enclosing_vars
->empty())
2859 // Get the variables in order by their field index.
2861 size_t enclosing_var_count
= enclosing_vars
->size();
2862 std::vector
<Enclosing_var
> ev(enclosing_var_count
);
2863 for (Enclosing_vars::const_iterator p
= enclosing_vars
->begin();
2864 p
!= enclosing_vars
->end();
2867 // Subtract 1 because index 0 is the function code.
2868 ev
[p
->index() - 1] = *p
;
2871 // Build an initializer for a composite literal of the closure's
2874 Named_object
* enclosing_function
= this->gogo_
->current_function();
2875 Expression_list
* initializer
= new Expression_list
;
2877 initializer
->push_back(Expression::make_func_code_reference(function
,
2880 for (size_t i
= 0; i
< enclosing_var_count
; ++i
)
2882 // Add 1 to i because the first field in the closure is a
2883 // pointer to the function code.
2884 go_assert(ev
[i
].index() == i
+ 1);
2885 Named_object
* var
= ev
[i
].var();
2887 if (ev
[i
].in_function() == enclosing_function
)
2888 ref
= Expression::make_var_reference(var
, location
);
2890 ref
= this->enclosing_var_reference(ev
[i
].in_function(), var
,
2892 Expression
* refaddr
= Expression::make_unary(OPERATOR_AND
, ref
,
2894 initializer
->push_back(refaddr
);
2897 Named_object
* closure_var
= function
->func_value()->closure_var();
2898 Struct_type
* st
= closure_var
->var_value()->type()->deref()->struct_type();
2899 Expression
* cv
= Expression::make_struct_composite_literal(st
, initializer
,
2901 return Expression::make_heap_expression(cv
, location
);
2904 // PrimaryExpr = Operand { Selector | Index | Slice | TypeGuard | Call } .
2906 // If MAY_BE_SINK is true, this expression may be "_".
2908 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
2911 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2912 // guard (var := expr.("type") using the literal keyword "type").
2914 // If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
2915 // if the entire expression is in parentheses.
2918 Parse::primary_expr(bool may_be_sink
, bool may_be_composite_lit
,
2919 bool* is_type_switch
, bool* is_parenthesized
)
2921 Location start_loc
= this->location();
2922 bool operand_is_parenthesized
= false;
2923 bool whole_is_parenthesized
= false;
2925 Expression
* ret
= this->operand(may_be_sink
, &operand_is_parenthesized
);
2927 whole_is_parenthesized
= operand_is_parenthesized
;
2929 // An unknown name followed by a curly brace must be a composite
2930 // literal, and the unknown name must be a type.
2931 if (may_be_composite_lit
2932 && !operand_is_parenthesized
2933 && ret
->unknown_expression() != NULL
2934 && this->peek_token()->is_op(OPERATOR_LCURLY
))
2936 Named_object
* no
= ret
->unknown_expression()->named_object();
2937 Type
* type
= Type::make_forward_declaration(no
);
2938 ret
= Expression::make_type(type
, ret
->location());
2941 // We handle composite literals and type casts here, as it is the
2942 // easiest way to handle types which are in parentheses, as in
2944 if (ret
->is_type_expression())
2946 if (this->peek_token()->is_op(OPERATOR_LCURLY
))
2948 whole_is_parenthesized
= false;
2949 if (!may_be_composite_lit
)
2951 Type
* t
= ret
->type();
2952 if (t
->named_type() != NULL
2953 || t
->forward_declaration_type() != NULL
)
2955 _("parentheses required around this composite literal "
2956 "to avoid parsing ambiguity"));
2958 else if (operand_is_parenthesized
)
2960 "cannot parenthesize type in composite literal");
2961 ret
= this->composite_lit(ret
->type(), 0, ret
->location());
2963 else if (this->peek_token()->is_op(OPERATOR_LPAREN
))
2965 whole_is_parenthesized
= false;
2966 Location loc
= this->location();
2967 this->advance_token();
2968 Expression
* expr
= this->expression(PRECEDENCE_NORMAL
, false, true,
2970 if (this->peek_token()->is_op(OPERATOR_COMMA
))
2971 this->advance_token();
2972 if (this->peek_token()->is_op(OPERATOR_ELLIPSIS
))
2974 error_at(this->location(),
2975 "invalid use of %<...%> in type conversion");
2976 this->advance_token();
2978 if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
2979 error_at(this->location(), "expected %<)%>");
2981 this->advance_token();
2982 if (expr
->is_error_expression())
2986 Type
* t
= ret
->type();
2987 if (t
->classification() == Type::TYPE_ARRAY
2988 && t
->array_type()->length() != NULL
2989 && t
->array_type()->length()->is_nil_expression())
2991 error_at(ret
->location(),
2992 "use of %<[...]%> outside of array literal");
2993 ret
= Expression::make_error(loc
);
2996 ret
= Expression::make_cast(t
, expr
, loc
);
3003 const Token
* token
= this->peek_token();
3004 if (token
->is_op(OPERATOR_LPAREN
))
3006 whole_is_parenthesized
= false;
3007 ret
= this->call(this->verify_not_sink(ret
));
3009 else if (token
->is_op(OPERATOR_DOT
))
3011 whole_is_parenthesized
= false;
3012 ret
= this->selector(this->verify_not_sink(ret
), is_type_switch
);
3013 if (is_type_switch
!= NULL
&& *is_type_switch
)
3016 else if (token
->is_op(OPERATOR_LSQUARE
))
3018 whole_is_parenthesized
= false;
3019 ret
= this->index(this->verify_not_sink(ret
));
3025 if (whole_is_parenthesized
&& is_parenthesized
!= NULL
)
3026 *is_parenthesized
= true;
3031 // Selector = "." identifier .
3032 // TypeGuard = "." "(" QualifiedIdent ")" .
3034 // Note that Operand can expand to QualifiedIdent, which contains a
3035 // ".". That is handled directly in operand when it sees a package
3038 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3039 // guard (var := expr.("type") using the literal keyword "type").
3042 Parse::selector(Expression
* left
, bool* is_type_switch
)
3044 go_assert(this->peek_token()->is_op(OPERATOR_DOT
));
3045 Location location
= this->location();
3047 const Token
* token
= this->advance_token();
3048 if (token
->is_identifier())
3050 // This could be a field in a struct, or a method in an
3051 // interface, or a method associated with a type. We can't know
3052 // which until we have seen all the types.
3054 this->gogo_
->pack_hidden_name(token
->identifier(),
3055 token
->is_identifier_exported());
3056 if (token
->identifier() == "_")
3058 error_at(this->location(), "invalid use of %<_%>");
3059 name
= Gogo::erroneous_name();
3061 this->advance_token();
3062 return Expression::make_selector(left
, name
, location
);
3064 else if (token
->is_op(OPERATOR_LPAREN
))
3066 this->advance_token();
3068 if (!this->peek_token()->is_keyword(KEYWORD_TYPE
))
3069 type
= this->type();
3072 if (is_type_switch
!= NULL
)
3073 *is_type_switch
= true;
3076 error_at(this->location(),
3077 "use of %<.(type)%> outside type switch");
3078 type
= Type::make_error_type();
3080 this->advance_token();
3082 if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
3083 error_at(this->location(), "missing %<)%>");
3085 this->advance_token();
3086 if (is_type_switch
!= NULL
&& *is_type_switch
)
3088 return Expression::make_type_guard(left
, type
, location
);
3092 error_at(this->location(), "expected identifier or %<(%>");
3097 // Index = "[" Expression "]" .
3098 // Slice = "[" Expression ":" [ Expression ] [ ":" Expression ] "]" .
3101 Parse::index(Expression
* expr
)
3103 Location location
= this->location();
3104 go_assert(this->peek_token()->is_op(OPERATOR_LSQUARE
));
3105 this->advance_token();
3108 if (!this->peek_token()->is_op(OPERATOR_COLON
))
3109 start
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
3113 mpz_init_set_ui(zero
, 0);
3114 start
= Expression::make_integer(&zero
, NULL
, location
);
3118 Expression
* end
= NULL
;
3119 if (this->peek_token()->is_op(OPERATOR_COLON
))
3121 // We use nil to indicate a missing high expression.
3122 if (this->advance_token()->is_op(OPERATOR_RSQUARE
))
3123 end
= Expression::make_nil(this->location());
3124 else if (this->peek_token()->is_op(OPERATOR_COLON
))
3126 error_at(this->location(), "middle index required in 3-index slice");
3127 end
= Expression::make_error(this->location());
3130 end
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
3133 Expression
* cap
= NULL
;
3134 if (this->peek_token()->is_op(OPERATOR_COLON
))
3136 if (this->advance_token()->is_op(OPERATOR_RSQUARE
))
3138 error_at(this->location(), "final index required in 3-index slice");
3139 cap
= Expression::make_error(this->location());
3142 cap
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
3144 if (!this->peek_token()->is_op(OPERATOR_RSQUARE
))
3145 error_at(this->location(), "missing %<]%>");
3147 this->advance_token();
3148 return Expression::make_index(expr
, start
, end
, cap
, location
);
3151 // Call = "(" [ ArgumentList [ "," ] ] ")" .
3152 // ArgumentList = ExpressionList [ "..." ] .
3155 Parse::call(Expression
* func
)
3157 go_assert(this->peek_token()->is_op(OPERATOR_LPAREN
));
3158 Expression_list
* args
= NULL
;
3159 bool is_varargs
= false;
3160 const Token
* token
= this->advance_token();
3161 if (!token
->is_op(OPERATOR_RPAREN
))
3163 args
= this->expression_list(NULL
, false, true);
3164 token
= this->peek_token();
3165 if (token
->is_op(OPERATOR_ELLIPSIS
))
3168 token
= this->advance_token();
3171 if (token
->is_op(OPERATOR_COMMA
))
3172 token
= this->advance_token();
3173 if (!token
->is_op(OPERATOR_RPAREN
))
3174 error_at(this->location(), "missing %<)%>");
3176 this->advance_token();
3177 if (func
->is_error_expression())
3179 return Expression::make_call(func
, args
, is_varargs
, func
->location());
3182 // Return an expression for a single unqualified identifier.
3185 Parse::id_to_expression(const std::string
& name
, Location location
,
3188 Named_object
* in_function
;
3189 Named_object
* named_object
= this->gogo_
->lookup(name
, &in_function
);
3190 if (named_object
== NULL
)
3191 named_object
= this->gogo_
->add_unknown_name(name
, location
);
3193 if (in_function
!= NULL
3194 && in_function
!= this->gogo_
->current_function()
3195 && (named_object
->is_variable() || named_object
->is_result_variable()))
3196 return this->enclosing_var_reference(in_function
, named_object
,
3199 switch (named_object
->classification())
3201 case Named_object::NAMED_OBJECT_CONST
:
3202 return Expression::make_const_reference(named_object
, location
);
3203 case Named_object::NAMED_OBJECT_VAR
:
3204 case Named_object::NAMED_OBJECT_RESULT_VAR
:
3206 this->mark_var_used(named_object
);
3207 return Expression::make_var_reference(named_object
, location
);
3208 case Named_object::NAMED_OBJECT_SINK
:
3209 return Expression::make_sink(location
);
3210 case Named_object::NAMED_OBJECT_FUNC
:
3211 case Named_object::NAMED_OBJECT_FUNC_DECLARATION
:
3212 return Expression::make_func_reference(named_object
, NULL
, location
);
3213 case Named_object::NAMED_OBJECT_UNKNOWN
:
3215 Unknown_expression
* ue
=
3216 Expression::make_unknown_reference(named_object
, location
);
3217 if (this->is_erroneous_function_
)
3218 ue
->set_no_error_message();
3221 case Named_object::NAMED_OBJECT_PACKAGE
:
3222 case Named_object::NAMED_OBJECT_TYPE
:
3223 case Named_object::NAMED_OBJECT_TYPE_DECLARATION
:
3225 // These cases can arise for a field name in a composite
3227 Unknown_expression
* ue
=
3228 Expression::make_unknown_reference(named_object
, location
);
3229 if (this->is_erroneous_function_
)
3230 ue
->set_no_error_message();
3233 case Named_object::NAMED_OBJECT_ERRONEOUS
:
3234 return Expression::make_error(location
);
3236 error_at(this->location(), "unexpected type of identifier");
3237 return Expression::make_error(location
);
3241 // Expression = UnaryExpr { binary_op Expression } .
3243 // PRECEDENCE is the precedence of the current operator.
3245 // If MAY_BE_SINK is true, this expression may be "_".
3247 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3250 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3251 // guard (var := expr.("type") using the literal keyword "type").
3253 // If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
3254 // if the entire expression is in parentheses.
3257 Parse::expression(Precedence precedence
, bool may_be_sink
,
3258 bool may_be_composite_lit
, bool* is_type_switch
,
3259 bool *is_parenthesized
)
3261 Expression
* left
= this->unary_expr(may_be_sink
, may_be_composite_lit
,
3262 is_type_switch
, is_parenthesized
);
3266 if (is_type_switch
!= NULL
&& *is_type_switch
)
3269 const Token
* token
= this->peek_token();
3270 if (token
->classification() != Token::TOKEN_OPERATOR
)
3276 Precedence right_precedence
;
3277 switch (token
->op())
3280 right_precedence
= PRECEDENCE_OROR
;
3282 case OPERATOR_ANDAND
:
3283 right_precedence
= PRECEDENCE_ANDAND
;
3286 case OPERATOR_NOTEQ
:
3291 right_precedence
= PRECEDENCE_RELOP
;
3294 case OPERATOR_MINUS
:
3297 right_precedence
= PRECEDENCE_ADDOP
;
3302 case OPERATOR_LSHIFT
:
3303 case OPERATOR_RSHIFT
:
3305 case OPERATOR_BITCLEAR
:
3306 right_precedence
= PRECEDENCE_MULOP
;
3309 right_precedence
= PRECEDENCE_INVALID
;
3313 if (right_precedence
== PRECEDENCE_INVALID
)
3319 if (is_parenthesized
!= NULL
)
3320 *is_parenthesized
= false;
3322 Operator op
= token
->op();
3323 Location binop_location
= token
->location();
3325 if (precedence
>= right_precedence
)
3327 // We've already seen A * B, and we see + C. We want to
3328 // return so that A * B becomes a group.
3332 this->advance_token();
3334 left
= this->verify_not_sink(left
);
3335 Expression
* right
= this->expression(right_precedence
, false,
3336 may_be_composite_lit
,
3338 left
= Expression::make_binary(op
, left
, right
, binop_location
);
3343 Parse::expression_may_start_here()
3345 const Token
* token
= this->peek_token();
3346 switch (token
->classification())
3348 case Token::TOKEN_INVALID
:
3349 case Token::TOKEN_EOF
:
3351 case Token::TOKEN_KEYWORD
:
3352 switch (token
->keyword())
3357 case KEYWORD_STRUCT
:
3358 case KEYWORD_INTERFACE
:
3363 case Token::TOKEN_IDENTIFIER
:
3365 case Token::TOKEN_STRING
:
3367 case Token::TOKEN_OPERATOR
:
3368 switch (token
->op())
3371 case OPERATOR_MINUS
:
3375 case OPERATOR_CHANOP
:
3377 case OPERATOR_LPAREN
:
3378 case OPERATOR_LSQUARE
:
3383 case Token::TOKEN_CHARACTER
:
3384 case Token::TOKEN_INTEGER
:
3385 case Token::TOKEN_FLOAT
:
3386 case Token::TOKEN_IMAGINARY
:
3393 // UnaryExpr = unary_op UnaryExpr | PrimaryExpr .
3395 // If MAY_BE_SINK is true, this expression may be "_".
3397 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3400 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3401 // guard (var := expr.("type") using the literal keyword "type").
3403 // If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
3404 // if the entire expression is in parentheses.
3407 Parse::unary_expr(bool may_be_sink
, bool may_be_composite_lit
,
3408 bool* is_type_switch
, bool* is_parenthesized
)
3410 const Token
* token
= this->peek_token();
3412 // There is a complex parse for <- chan. The choices are
3413 // Convert x to type <- chan int:
3415 // Receive from (x converted to type chan <- chan int):
3416 // (<- chan <- chan int (x))
3417 // Convert x to type <- chan (<- chan int).
3418 // (<- chan <- chan int)(x)
3419 if (token
->is_op(OPERATOR_CHANOP
))
3421 Location location
= token
->location();
3422 if (this->advance_token()->is_keyword(KEYWORD_CHAN
))
3424 Expression
* expr
= this->primary_expr(false, may_be_composite_lit
,
3426 if (expr
->is_error_expression())
3428 else if (!expr
->is_type_expression())
3429 return Expression::make_receive(expr
, location
);
3432 if (expr
->type()->is_error_type())
3435 // We picked up "chan TYPE", but it is not a type
3437 Channel_type
* ct
= expr
->type()->channel_type();
3440 // This is probably impossible.
3441 error_at(location
, "expected channel type");
3442 return Expression::make_error(location
);
3444 else if (ct
->may_receive())
3447 Type
* t
= Type::make_channel_type(false, true,
3448 ct
->element_type());
3449 return Expression::make_type(t
, location
);
3453 // <- chan <- TYPE. Because we skipped the leading
3454 // <-, we parsed this as chan <- TYPE. With the
3455 // leading <-, we parse it as <- chan (<- TYPE).
3456 Type
*t
= this->reassociate_chan_direction(ct
, location
);
3457 return Expression::make_type(t
, location
);
3462 this->unget_token(Token::make_operator_token(OPERATOR_CHANOP
, location
));
3463 token
= this->peek_token();
3466 if (token
->is_op(OPERATOR_PLUS
)
3467 || token
->is_op(OPERATOR_MINUS
)
3468 || token
->is_op(OPERATOR_NOT
)
3469 || token
->is_op(OPERATOR_XOR
)
3470 || token
->is_op(OPERATOR_CHANOP
)
3471 || token
->is_op(OPERATOR_MULT
)
3472 || token
->is_op(OPERATOR_AND
))
3474 Location location
= token
->location();
3475 Operator op
= token
->op();
3476 this->advance_token();
3478 Expression
* expr
= this->unary_expr(false, may_be_composite_lit
, NULL
,
3480 if (expr
->is_error_expression())
3482 else if (op
== OPERATOR_MULT
&& expr
->is_type_expression())
3483 expr
= Expression::make_type(Type::make_pointer_type(expr
->type()),
3485 else if (op
== OPERATOR_AND
&& expr
->is_composite_literal())
3486 expr
= Expression::make_heap_expression(expr
, location
);
3487 else if (op
!= OPERATOR_CHANOP
)
3488 expr
= Expression::make_unary(op
, expr
, location
);
3490 expr
= Expression::make_receive(expr
, location
);
3494 return this->primary_expr(may_be_sink
, may_be_composite_lit
,
3495 is_type_switch
, is_parenthesized
);
3498 // This is called for the obscure case of
3499 // (<- chan <- chan int)(x)
3500 // In unary_expr we remove the leading <- and parse the remainder,
3502 // chan <- (chan int)
3503 // When we add the leading <- back in, we really want
3504 // <- chan (<- chan int)
3505 // This means that we need to reassociate.
3508 Parse::reassociate_chan_direction(Channel_type
*ct
, Location location
)
3510 Channel_type
* ele
= ct
->element_type()->channel_type();
3513 error_at(location
, "parse error");
3514 return Type::make_error_type();
3517 if (ele
->may_send())
3518 sub
= Type::make_channel_type(false, true, ele
->element_type());
3520 sub
= this->reassociate_chan_direction(ele
, location
);
3521 return Type::make_channel_type(false, true, sub
);
3525 // Declaration | LabeledStmt | SimpleStmt |
3526 // GoStmt | ReturnStmt | BreakStmt | ContinueStmt | GotoStmt |
3527 // FallthroughStmt | Block | IfStmt | SwitchStmt | SelectStmt | ForStmt |
3530 // LABEL is the label of this statement if it has one.
3533 Parse::statement(Label
* label
)
3535 const Token
* token
= this->peek_token();
3536 switch (token
->classification())
3538 case Token::TOKEN_KEYWORD
:
3540 switch (token
->keyword())
3545 this->declaration();
3549 case KEYWORD_STRUCT
:
3550 case KEYWORD_INTERFACE
:
3551 this->simple_stat(true, NULL
, NULL
, NULL
);
3555 this->go_or_defer_stat();
3557 case KEYWORD_RETURN
:
3558 this->return_stat();
3563 case KEYWORD_CONTINUE
:
3564 this->continue_stat();
3572 case KEYWORD_SWITCH
:
3573 this->switch_stat(label
);
3575 case KEYWORD_SELECT
:
3576 this->select_stat(label
);
3579 this->for_stat(label
);
3582 error_at(this->location(), "expected statement");
3583 this->advance_token();
3589 case Token::TOKEN_IDENTIFIER
:
3591 std::string identifier
= token
->identifier();
3592 bool is_exported
= token
->is_identifier_exported();
3593 Location location
= token
->location();
3594 if (this->advance_token()->is_op(OPERATOR_COLON
))
3596 this->advance_token();
3597 this->labeled_stmt(identifier
, location
);
3601 this->unget_token(Token::make_identifier_token(identifier
,
3604 this->simple_stat(true, NULL
, NULL
, NULL
);
3609 case Token::TOKEN_OPERATOR
:
3610 if (token
->is_op(OPERATOR_LCURLY
))
3612 Location location
= token
->location();
3613 this->gogo_
->start_block(location
);
3614 Location end_loc
= this->block();
3615 this->gogo_
->add_block(this->gogo_
->finish_block(end_loc
),
3618 else if (!token
->is_op(OPERATOR_SEMICOLON
))
3619 this->simple_stat(true, NULL
, NULL
, NULL
);
3622 case Token::TOKEN_STRING
:
3623 case Token::TOKEN_CHARACTER
:
3624 case Token::TOKEN_INTEGER
:
3625 case Token::TOKEN_FLOAT
:
3626 case Token::TOKEN_IMAGINARY
:
3627 this->simple_stat(true, NULL
, NULL
, NULL
);
3631 error_at(this->location(), "expected statement");
3632 this->advance_token();
3638 Parse::statement_may_start_here()
3640 const Token
* token
= this->peek_token();
3641 switch (token
->classification())
3643 case Token::TOKEN_KEYWORD
:
3645 switch (token
->keyword())
3652 case KEYWORD_STRUCT
:
3653 case KEYWORD_INTERFACE
:
3656 case KEYWORD_RETURN
:
3658 case KEYWORD_CONTINUE
:
3661 case KEYWORD_SWITCH
:
3662 case KEYWORD_SELECT
:
3672 case Token::TOKEN_IDENTIFIER
:
3675 case Token::TOKEN_OPERATOR
:
3676 if (token
->is_op(OPERATOR_LCURLY
)
3677 || token
->is_op(OPERATOR_SEMICOLON
))
3680 return this->expression_may_start_here();
3682 case Token::TOKEN_STRING
:
3683 case Token::TOKEN_CHARACTER
:
3684 case Token::TOKEN_INTEGER
:
3685 case Token::TOKEN_FLOAT
:
3686 case Token::TOKEN_IMAGINARY
:
3694 // LabeledStmt = Label ":" Statement .
3695 // Label = identifier .
3698 Parse::labeled_stmt(const std::string
& label_name
, Location location
)
3700 Label
* label
= this->gogo_
->add_label_definition(label_name
, location
);
3702 if (this->peek_token()->is_op(OPERATOR_RCURLY
))
3704 // This is a label at the end of a block. A program is
3705 // permitted to omit a semicolon here.
3709 if (!this->statement_may_start_here())
3711 // Mark the label as used to avoid a useless error about an
3714 label
->set_is_used();
3716 error_at(location
, "missing statement after label");
3717 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON
,
3722 this->statement(label
);
3725 // SimpleStmt = EmptyStmt | ExpressionStmt | SendStmt | IncDecStmt |
3726 // Assignment | ShortVarDecl .
3728 // EmptyStmt was handled in Parse::statement.
3730 // In order to make this work for if and switch statements, if
3731 // RETURN_EXP is not NULL, and we see an ExpressionStat, we return the
3732 // expression rather than adding an expression statement to the
3733 // current block. If we see something other than an ExpressionStat,
3734 // we add the statement, set *RETURN_EXP to true if we saw a send
3735 // statement, and return NULL. The handling of send statements is for
3736 // better error messages.
3738 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
3741 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
3742 // guard (var := expr.("type") using the literal keyword "type").
3745 Parse::simple_stat(bool may_be_composite_lit
, bool* return_exp
,
3746 Range_clause
* p_range_clause
, Type_switch
* p_type_switch
)
3748 const Token
* token
= this->peek_token();
3750 // An identifier follow by := is a SimpleVarDecl.
3751 if (token
->is_identifier())
3753 std::string identifier
= token
->identifier();
3754 bool is_exported
= token
->is_identifier_exported();
3755 Location location
= token
->location();
3757 token
= this->advance_token();
3758 if (token
->is_op(OPERATOR_COLONEQ
)
3759 || token
->is_op(OPERATOR_COMMA
))
3761 identifier
= this->gogo_
->pack_hidden_name(identifier
, is_exported
);
3762 this->simple_var_decl_or_assignment(identifier
, location
,
3763 may_be_composite_lit
,
3765 (token
->is_op(OPERATOR_COLONEQ
)
3771 this->unget_token(Token::make_identifier_token(identifier
, is_exported
,
3774 else if (p_range_clause
!= NULL
&& token
->is_keyword(KEYWORD_RANGE
))
3776 Typed_identifier_list til
;
3777 this->range_clause_decl(&til
, p_range_clause
);
3781 Expression
* exp
= this->expression(PRECEDENCE_NORMAL
, true,
3782 may_be_composite_lit
,
3783 (p_type_switch
== NULL
3785 : &p_type_switch
->found
),
3787 if (p_type_switch
!= NULL
&& p_type_switch
->found
)
3789 p_type_switch
->name
.clear();
3790 p_type_switch
->location
= exp
->location();
3791 p_type_switch
->expr
= this->verify_not_sink(exp
);
3794 token
= this->peek_token();
3795 if (token
->is_op(OPERATOR_CHANOP
))
3797 this->send_stmt(this->verify_not_sink(exp
));
3798 if (return_exp
!= NULL
)
3801 else if (token
->is_op(OPERATOR_PLUSPLUS
)
3802 || token
->is_op(OPERATOR_MINUSMINUS
))
3803 this->inc_dec_stat(this->verify_not_sink(exp
));
3804 else if (token
->is_op(OPERATOR_COMMA
)
3805 || token
->is_op(OPERATOR_EQ
))
3806 this->assignment(exp
, may_be_composite_lit
, p_range_clause
);
3807 else if (token
->is_op(OPERATOR_PLUSEQ
)
3808 || token
->is_op(OPERATOR_MINUSEQ
)
3809 || token
->is_op(OPERATOR_OREQ
)
3810 || token
->is_op(OPERATOR_XOREQ
)
3811 || token
->is_op(OPERATOR_MULTEQ
)
3812 || token
->is_op(OPERATOR_DIVEQ
)
3813 || token
->is_op(OPERATOR_MODEQ
)
3814 || token
->is_op(OPERATOR_LSHIFTEQ
)
3815 || token
->is_op(OPERATOR_RSHIFTEQ
)
3816 || token
->is_op(OPERATOR_ANDEQ
)
3817 || token
->is_op(OPERATOR_BITCLEAREQ
))
3818 this->assignment(this->verify_not_sink(exp
), may_be_composite_lit
,
3820 else if (return_exp
!= NULL
)
3821 return this->verify_not_sink(exp
);
3824 exp
= this->verify_not_sink(exp
);
3826 if (token
->is_op(OPERATOR_COLONEQ
))
3828 if (!exp
->is_error_expression())
3829 error_at(token
->location(), "non-name on left side of %<:=%>");
3830 this->gogo_
->mark_locals_used();
3831 while (!token
->is_op(OPERATOR_SEMICOLON
)
3832 && !token
->is_eof())
3833 token
= this->advance_token();
3837 this->expression_stat(exp
);
3844 Parse::simple_stat_may_start_here()
3846 return this->expression_may_start_here();
3849 // Parse { Statement ";" } which is used in a few places. The list of
3850 // statements may end with a right curly brace, in which case the
3851 // semicolon may be omitted.
3854 Parse::statement_list()
3856 while (this->statement_may_start_here())
3858 this->statement(NULL
);
3859 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
3860 this->advance_token();
3861 else if (this->peek_token()->is_op(OPERATOR_RCURLY
))
3865 if (!this->peek_token()->is_eof() || !saw_errors())
3866 error_at(this->location(), "expected %<;%> or %<}%> or newline");
3867 if (!this->skip_past_error(OPERATOR_RCURLY
))
3874 Parse::statement_list_may_start_here()
3876 return this->statement_may_start_here();
3879 // ExpressionStat = Expression .
3882 Parse::expression_stat(Expression
* exp
)
3884 this->gogo_
->add_statement(Statement::make_statement(exp
, false));
3887 // SendStmt = Channel "<-" Expression .
3888 // Channel = Expression .
3891 Parse::send_stmt(Expression
* channel
)
3893 go_assert(this->peek_token()->is_op(OPERATOR_CHANOP
));
3894 Location loc
= this->location();
3895 this->advance_token();
3896 Expression
* val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
,
3898 Statement
* s
= Statement::make_send_statement(channel
, val
, loc
);
3899 this->gogo_
->add_statement(s
);
3902 // IncDecStat = Expression ( "++" | "--" ) .
3905 Parse::inc_dec_stat(Expression
* exp
)
3907 const Token
* token
= this->peek_token();
3909 // Lvalue maps require special handling.
3910 if (exp
->index_expression() != NULL
)
3911 exp
->index_expression()->set_is_lvalue();
3913 if (token
->is_op(OPERATOR_PLUSPLUS
))
3914 this->gogo_
->add_statement(Statement::make_inc_statement(exp
));
3915 else if (token
->is_op(OPERATOR_MINUSMINUS
))
3916 this->gogo_
->add_statement(Statement::make_dec_statement(exp
));
3919 this->advance_token();
3922 // Assignment = ExpressionList assign_op ExpressionList .
3924 // EXP is an expression that we have already parsed.
3926 // If MAY_BE_COMPOSITE_LIT is true, an expression on the right hand
3927 // side may be a composite literal.
3929 // If RANGE_CLAUSE is not NULL, then this will recognize a
3933 Parse::assignment(Expression
* expr
, bool may_be_composite_lit
,
3934 Range_clause
* p_range_clause
)
3936 Expression_list
* vars
;
3937 if (!this->peek_token()->is_op(OPERATOR_COMMA
))
3939 vars
= new Expression_list();
3940 vars
->push_back(expr
);
3944 this->advance_token();
3945 vars
= this->expression_list(expr
, true, may_be_composite_lit
);
3948 this->tuple_assignment(vars
, may_be_composite_lit
, p_range_clause
);
3951 // An assignment statement. LHS is the list of expressions which
3952 // appear on the left hand side.
3954 // If MAY_BE_COMPOSITE_LIT is true, an expression on the right hand
3955 // side may be a composite literal.
3957 // If RANGE_CLAUSE is not NULL, then this will recognize a
3961 Parse::tuple_assignment(Expression_list
* lhs
, bool may_be_composite_lit
,
3962 Range_clause
* p_range_clause
)
3964 const Token
* token
= this->peek_token();
3965 if (!token
->is_op(OPERATOR_EQ
)
3966 && !token
->is_op(OPERATOR_PLUSEQ
)
3967 && !token
->is_op(OPERATOR_MINUSEQ
)
3968 && !token
->is_op(OPERATOR_OREQ
)
3969 && !token
->is_op(OPERATOR_XOREQ
)
3970 && !token
->is_op(OPERATOR_MULTEQ
)
3971 && !token
->is_op(OPERATOR_DIVEQ
)
3972 && !token
->is_op(OPERATOR_MODEQ
)
3973 && !token
->is_op(OPERATOR_LSHIFTEQ
)
3974 && !token
->is_op(OPERATOR_RSHIFTEQ
)
3975 && !token
->is_op(OPERATOR_ANDEQ
)
3976 && !token
->is_op(OPERATOR_BITCLEAREQ
))
3978 error_at(this->location(), "expected assignment operator");
3981 Operator op
= token
->op();
3982 Location location
= token
->location();
3984 token
= this->advance_token();
3986 if (p_range_clause
!= NULL
&& token
->is_keyword(KEYWORD_RANGE
))
3988 if (op
!= OPERATOR_EQ
)
3989 error_at(this->location(), "range clause requires %<=%>");
3990 this->range_clause_expr(lhs
, p_range_clause
);
3994 Expression_list
* vals
= this->expression_list(NULL
, false,
3995 may_be_composite_lit
);
3997 // We've parsed everything; check for errors.
3998 if (lhs
== NULL
|| vals
== NULL
)
4000 for (Expression_list::const_iterator pe
= lhs
->begin();
4004 if ((*pe
)->is_error_expression())
4006 if (op
!= OPERATOR_EQ
&& (*pe
)->is_sink_expression())
4007 error_at((*pe
)->location(), "cannot use _ as value");
4009 for (Expression_list::const_iterator pe
= vals
->begin();
4013 if ((*pe
)->is_error_expression())
4017 // Map expressions act differently when they are lvalues.
4018 for (Expression_list::iterator plv
= lhs
->begin();
4021 if ((*plv
)->index_expression() != NULL
)
4022 (*plv
)->index_expression()->set_is_lvalue();
4024 Call_expression
* call
;
4025 Index_expression
* map_index
;
4026 Receive_expression
* receive
;
4027 Type_guard_expression
* type_guard
;
4028 if (lhs
->size() == vals
->size())
4031 if (lhs
->size() > 1)
4033 if (op
!= OPERATOR_EQ
)
4034 error_at(location
, "multiple values only permitted with %<=%>");
4035 s
= Statement::make_tuple_assignment(lhs
, vals
, location
);
4039 if (op
== OPERATOR_EQ
)
4040 s
= Statement::make_assignment(lhs
->front(), vals
->front(),
4043 s
= Statement::make_assignment_operation(op
, lhs
->front(),
4044 vals
->front(), location
);
4048 this->gogo_
->add_statement(s
);
4050 else if (vals
->size() == 1
4051 && (call
= (*vals
->begin())->call_expression()) != NULL
)
4053 if (op
!= OPERATOR_EQ
)
4054 error_at(location
, "multiple results only permitted with %<=%>");
4055 call
->set_expected_result_count(lhs
->size());
4057 vals
= new Expression_list
;
4058 for (unsigned int i
= 0; i
< lhs
->size(); ++i
)
4059 vals
->push_back(Expression::make_call_result(call
, i
));
4060 Statement
* s
= Statement::make_tuple_assignment(lhs
, vals
, location
);
4061 this->gogo_
->add_statement(s
);
4063 else if (lhs
->size() == 2
4064 && vals
->size() == 1
4065 && (map_index
= (*vals
->begin())->index_expression()) != NULL
)
4067 if (op
!= OPERATOR_EQ
)
4068 error_at(location
, "two values from map requires %<=%>");
4069 Expression
* val
= lhs
->front();
4070 Expression
* present
= lhs
->back();
4071 Statement
* s
= Statement::make_tuple_map_assignment(val
, present
,
4072 map_index
, location
);
4073 this->gogo_
->add_statement(s
);
4075 else if (lhs
->size() == 1
4076 && vals
->size() == 2
4077 && (map_index
= lhs
->front()->index_expression()) != NULL
)
4079 if (op
!= OPERATOR_EQ
)
4080 error_at(location
, "assigning tuple to map index requires %<=%>");
4081 Expression
* val
= vals
->front();
4082 Expression
* should_set
= vals
->back();
4083 Statement
* s
= Statement::make_map_assignment(map_index
, val
, should_set
,
4085 this->gogo_
->add_statement(s
);
4087 else if (lhs
->size() == 2
4088 && vals
->size() == 1
4089 && (receive
= (*vals
->begin())->receive_expression()) != NULL
)
4091 if (op
!= OPERATOR_EQ
)
4092 error_at(location
, "two values from receive requires %<=%>");
4093 Expression
* val
= lhs
->front();
4094 Expression
* success
= lhs
->back();
4095 Expression
* channel
= receive
->channel();
4096 Statement
* s
= Statement::make_tuple_receive_assignment(val
, success
,
4099 this->gogo_
->add_statement(s
);
4101 else if (lhs
->size() == 2
4102 && vals
->size() == 1
4103 && (type_guard
= (*vals
->begin())->type_guard_expression()) != NULL
)
4105 if (op
!= OPERATOR_EQ
)
4106 error_at(location
, "two values from type guard requires %<=%>");
4107 Expression
* val
= lhs
->front();
4108 Expression
* ok
= lhs
->back();
4109 Expression
* expr
= type_guard
->expr();
4110 Type
* type
= type_guard
->type();
4111 Statement
* s
= Statement::make_tuple_type_guard_assignment(val
, ok
,
4114 this->gogo_
->add_statement(s
);
4118 error_at(location
, "number of variables does not match number of values");
4122 // GoStat = "go" Expression .
4123 // DeferStat = "defer" Expression .
4126 Parse::go_or_defer_stat()
4128 go_assert(this->peek_token()->is_keyword(KEYWORD_GO
)
4129 || this->peek_token()->is_keyword(KEYWORD_DEFER
));
4130 bool is_go
= this->peek_token()->is_keyword(KEYWORD_GO
);
4131 Location stat_location
= this->location();
4133 this->advance_token();
4134 Location expr_location
= this->location();
4136 bool is_parenthesized
= false;
4137 Expression
* expr
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
,
4139 Call_expression
* call_expr
= expr
->call_expression();
4140 if (is_parenthesized
|| call_expr
== NULL
)
4142 error_at(expr_location
, "argument to go/defer must be function call");
4146 // Make it easier to simplify go/defer statements by putting every
4147 // statement in its own block.
4148 this->gogo_
->start_block(stat_location
);
4151 stat
= Statement::make_go_statement(call_expr
, stat_location
);
4153 stat
= Statement::make_defer_statement(call_expr
, stat_location
);
4154 this->gogo_
->add_statement(stat
);
4155 this->gogo_
->add_block(this->gogo_
->finish_block(stat_location
),
4159 // ReturnStat = "return" [ ExpressionList ] .
4162 Parse::return_stat()
4164 go_assert(this->peek_token()->is_keyword(KEYWORD_RETURN
));
4165 Location location
= this->location();
4166 this->advance_token();
4167 Expression_list
* vals
= NULL
;
4168 if (this->expression_may_start_here())
4169 vals
= this->expression_list(NULL
, false, true);
4170 this->gogo_
->add_statement(Statement::make_return_statement(vals
, location
));
4173 && this->gogo_
->current_function()->func_value()->results_are_named())
4175 Named_object
* function
= this->gogo_
->current_function();
4176 Function::Results
* results
= function
->func_value()->result_variables();
4177 for (Function::Results::const_iterator p
= results
->begin();
4178 p
!= results
->end();
4181 Named_object
* no
= this->gogo_
->lookup((*p
)->name(), NULL
);
4183 go_assert(saw_errors());
4184 else if (!no
->is_result_variable())
4185 error_at(location
, "%qs is shadowed during return",
4186 (*p
)->message_name().c_str());
4191 // IfStmt = "if" [ SimpleStmt ";" ] Expression Block
4192 // [ "else" ( IfStmt | Block ) ] .
4197 go_assert(this->peek_token()->is_keyword(KEYWORD_IF
));
4198 Location location
= this->location();
4199 this->advance_token();
4201 this->gogo_
->start_block(location
);
4203 bool saw_simple_stat
= false;
4204 Expression
* cond
= NULL
;
4205 bool saw_send_stmt
= false;
4206 if (this->simple_stat_may_start_here())
4208 cond
= this->simple_stat(false, &saw_send_stmt
, NULL
, NULL
);
4209 saw_simple_stat
= true;
4211 if (cond
!= NULL
&& this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4213 // The SimpleStat is an expression statement.
4214 this->expression_stat(cond
);
4219 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4220 this->advance_token();
4221 else if (saw_simple_stat
)
4224 error_at(this->location(),
4225 ("send statement used as value; "
4226 "use select for non-blocking send"));
4228 error_at(this->location(),
4229 "expected %<;%> after statement in if expression");
4230 if (!this->expression_may_start_here())
4231 cond
= Expression::make_error(this->location());
4233 if (cond
== NULL
&& this->peek_token()->is_op(OPERATOR_LCURLY
))
4235 error_at(this->location(),
4236 "missing condition in if statement");
4237 cond
= Expression::make_error(this->location());
4240 cond
= this->expression(PRECEDENCE_NORMAL
, false, false, NULL
, NULL
);
4243 // Check for the easy error of a newline before starting the block.
4244 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4246 Location semi_loc
= this->location();
4247 if (this->advance_token()->is_op(OPERATOR_LCURLY
))
4248 error_at(semi_loc
, "missing %<{%> after if clause");
4249 // Otherwise we will get an error when we call this->block
4253 this->gogo_
->start_block(this->location());
4254 Location end_loc
= this->block();
4255 Block
* then_block
= this->gogo_
->finish_block(end_loc
);
4257 // Check for the easy error of a newline before "else".
4258 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4260 Location semi_loc
= this->location();
4261 if (this->advance_token()->is_keyword(KEYWORD_ELSE
))
4262 error_at(this->location(),
4263 "unexpected semicolon or newline before %<else%>");
4265 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON
,
4269 Block
* else_block
= NULL
;
4270 if (this->peek_token()->is_keyword(KEYWORD_ELSE
))
4272 this->gogo_
->start_block(this->location());
4273 const Token
* token
= this->advance_token();
4274 if (token
->is_keyword(KEYWORD_IF
))
4276 else if (token
->is_op(OPERATOR_LCURLY
))
4280 error_at(this->location(), "expected %<if%> or %<{%>");
4281 this->statement(NULL
);
4283 else_block
= this->gogo_
->finish_block(this->location());
4286 this->gogo_
->add_statement(Statement::make_if_statement(cond
, then_block
,
4290 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4294 // SwitchStmt = ExprSwitchStmt | TypeSwitchStmt .
4295 // ExprSwitchStmt = "switch" [ [ SimpleStat ] ";" ] [ Expression ]
4296 // "{" { ExprCaseClause } "}" .
4297 // TypeSwitchStmt = "switch" [ [ SimpleStat ] ";" ] TypeSwitchGuard
4298 // "{" { TypeCaseClause } "}" .
4299 // TypeSwitchGuard = [ identifier ":=" ] Expression "." "(" "type" ")" .
4302 Parse::switch_stat(Label
* label
)
4304 go_assert(this->peek_token()->is_keyword(KEYWORD_SWITCH
));
4305 Location location
= this->location();
4306 this->advance_token();
4308 this->gogo_
->start_block(location
);
4310 bool saw_simple_stat
= false;
4311 Expression
* switch_val
= NULL
;
4313 Type_switch type_switch
;
4314 bool have_type_switch_block
= false;
4315 if (this->simple_stat_may_start_here())
4317 switch_val
= this->simple_stat(false, &saw_send_stmt
, NULL
,
4319 saw_simple_stat
= true;
4321 if (switch_val
!= NULL
&& this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4323 // The SimpleStat is an expression statement.
4324 this->expression_stat(switch_val
);
4327 if (switch_val
== NULL
&& !type_switch
.found
)
4329 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4330 this->advance_token();
4331 else if (saw_simple_stat
)
4334 error_at(this->location(),
4335 ("send statement used as value; "
4336 "use select for non-blocking send"));
4338 error_at(this->location(),
4339 "expected %<;%> after statement in switch expression");
4341 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
4343 if (this->peek_token()->is_identifier())
4345 const Token
* token
= this->peek_token();
4346 std::string identifier
= token
->identifier();
4347 bool is_exported
= token
->is_identifier_exported();
4348 Location id_loc
= token
->location();
4350 token
= this->advance_token();
4351 bool is_coloneq
= token
->is_op(OPERATOR_COLONEQ
);
4352 this->unget_token(Token::make_identifier_token(identifier
,
4357 // This must be a TypeSwitchGuard. It is in a
4358 // different block from any initial SimpleStat.
4359 if (saw_simple_stat
)
4361 this->gogo_
->start_block(id_loc
);
4362 have_type_switch_block
= true;
4365 switch_val
= this->simple_stat(false, &saw_send_stmt
, NULL
,
4367 if (!type_switch
.found
)
4369 if (switch_val
== NULL
4370 || !switch_val
->is_error_expression())
4372 error_at(id_loc
, "expected type switch assignment");
4373 switch_val
= Expression::make_error(id_loc
);
4378 if (switch_val
== NULL
&& !type_switch
.found
)
4380 switch_val
= this->expression(PRECEDENCE_NORMAL
, false, false,
4381 &type_switch
.found
, NULL
);
4382 if (type_switch
.found
)
4384 type_switch
.name
.clear();
4385 type_switch
.expr
= switch_val
;
4386 type_switch
.location
= switch_val
->location();
4392 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
4394 Location token_loc
= this->location();
4395 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
4396 && this->advance_token()->is_op(OPERATOR_LCURLY
))
4397 error_at(token_loc
, "missing %<{%> after switch clause");
4398 else if (this->peek_token()->is_op(OPERATOR_COLONEQ
))
4400 error_at(token_loc
, "invalid variable name");
4401 this->advance_token();
4402 this->expression(PRECEDENCE_NORMAL
, false, false,
4403 &type_switch
.found
, NULL
);
4404 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4405 this->advance_token();
4406 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
4408 if (have_type_switch_block
)
4409 this->gogo_
->add_block(this->gogo_
->finish_block(location
),
4411 this->gogo_
->add_block(this->gogo_
->finish_block(location
),
4415 if (type_switch
.found
)
4416 type_switch
.expr
= Expression::make_error(location
);
4420 error_at(this->location(), "expected %<{%>");
4421 if (have_type_switch_block
)
4422 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4424 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4429 this->advance_token();
4431 Statement
* statement
;
4432 if (type_switch
.found
)
4433 statement
= this->type_switch_body(label
, type_switch
, location
);
4435 statement
= this->expr_switch_body(label
, switch_val
, location
);
4437 if (statement
!= NULL
)
4438 this->gogo_
->add_statement(statement
);
4440 if (have_type_switch_block
)
4441 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4444 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4448 // The body of an expression switch.
4449 // "{" { ExprCaseClause } "}"
4452 Parse::expr_switch_body(Label
* label
, Expression
* switch_val
,
4455 Switch_statement
* statement
= Statement::make_switch_statement(switch_val
,
4458 this->push_break_statement(statement
, label
);
4460 Case_clauses
* case_clauses
= new Case_clauses();
4461 bool saw_default
= false;
4462 while (!this->peek_token()->is_op(OPERATOR_RCURLY
))
4464 if (this->peek_token()->is_eof())
4467 error_at(this->location(), "missing %<}%>");
4470 this->expr_case_clause(case_clauses
, &saw_default
);
4472 this->advance_token();
4474 statement
->add_clauses(case_clauses
);
4476 this->pop_break_statement();
4481 // ExprCaseClause = ExprSwitchCase ":" [ StatementList ] .
4482 // FallthroughStat = "fallthrough" .
4485 Parse::expr_case_clause(Case_clauses
* clauses
, bool* saw_default
)
4487 Location location
= this->location();
4489 bool is_default
= false;
4490 Expression_list
* vals
= this->expr_switch_case(&is_default
);
4492 if (!this->peek_token()->is_op(OPERATOR_COLON
))
4495 error_at(this->location(), "expected %<:%>");
4499 this->advance_token();
4501 Block
* statements
= NULL
;
4502 if (this->statement_list_may_start_here())
4504 this->gogo_
->start_block(this->location());
4505 this->statement_list();
4506 statements
= this->gogo_
->finish_block(this->location());
4509 bool is_fallthrough
= false;
4510 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH
))
4512 Location fallthrough_loc
= this->location();
4513 is_fallthrough
= true;
4514 if (this->advance_token()->is_op(OPERATOR_SEMICOLON
))
4515 this->advance_token();
4516 if (this->peek_token()->is_op(OPERATOR_RCURLY
))
4517 error_at(fallthrough_loc
, _("cannot fallthrough final case in switch"));
4524 error_at(location
, "multiple defaults in switch");
4527 *saw_default
= true;
4530 if (is_default
|| vals
!= NULL
)
4531 clauses
->add(vals
, is_default
, statements
, is_fallthrough
, location
);
4534 // ExprSwitchCase = "case" ExpressionList | "default" .
4537 Parse::expr_switch_case(bool* is_default
)
4539 const Token
* token
= this->peek_token();
4540 if (token
->is_keyword(KEYWORD_CASE
))
4542 this->advance_token();
4543 return this->expression_list(NULL
, false, true);
4545 else if (token
->is_keyword(KEYWORD_DEFAULT
))
4547 this->advance_token();
4554 error_at(this->location(), "expected %<case%> or %<default%>");
4555 if (!token
->is_op(OPERATOR_RCURLY
))
4556 this->advance_token();
4561 // The body of a type switch.
4562 // "{" { TypeCaseClause } "}" .
4565 Parse::type_switch_body(Label
* label
, const Type_switch
& type_switch
,
4568 Named_object
* switch_no
= NULL
;
4569 if (!type_switch
.name
.empty())
4571 if (Gogo::is_sink_name(type_switch
.name
))
4572 error_at(type_switch
.location
,
4573 "no new variables on left side of %<:=%>");
4576 Variable
* switch_var
= new Variable(NULL
, type_switch
.expr
, false,
4578 type_switch
.location
);
4579 switch_no
= this->gogo_
->add_variable(type_switch
.name
, switch_var
);
4583 Type_switch_statement
* statement
=
4584 Statement::make_type_switch_statement(switch_no
,
4590 this->push_break_statement(statement
, label
);
4592 Type_case_clauses
* case_clauses
= new Type_case_clauses();
4593 bool saw_default
= false;
4594 while (!this->peek_token()->is_op(OPERATOR_RCURLY
))
4596 if (this->peek_token()->is_eof())
4598 error_at(this->location(), "missing %<}%>");
4601 this->type_case_clause(switch_no
, case_clauses
, &saw_default
);
4603 this->advance_token();
4605 statement
->add_clauses(case_clauses
);
4607 this->pop_break_statement();
4612 // TypeCaseClause = TypeSwitchCase ":" [ StatementList ] .
4615 Parse::type_case_clause(Named_object
* switch_no
, Type_case_clauses
* clauses
,
4618 Location location
= this->location();
4620 std::vector
<Type
*> types
;
4621 bool is_default
= false;
4622 this->type_switch_case(&types
, &is_default
);
4624 if (!this->peek_token()->is_op(OPERATOR_COLON
))
4625 error_at(this->location(), "expected %<:%>");
4627 this->advance_token();
4629 Block
* statements
= NULL
;
4630 if (this->statement_list_may_start_here())
4632 this->gogo_
->start_block(this->location());
4633 if (switch_no
!= NULL
&& types
.size() == 1)
4635 Type
* type
= types
.front();
4636 Expression
* init
= Expression::make_var_reference(switch_no
,
4638 init
= Expression::make_type_guard(init
, type
, location
);
4639 Variable
* v
= new Variable(type
, init
, false, false, false,
4641 v
->set_is_type_switch_var();
4642 Named_object
* no
= this->gogo_
->add_variable(switch_no
->name(), v
);
4644 // We don't want to issue an error if the compiler
4645 // introduced special variable is not used. Instead we want
4646 // to issue an error if the variable defined by the switch
4647 // is not used. That is handled via type_switch_vars_ and
4648 // Parse::mark_var_used.
4650 this->type_switch_vars_
[no
] = switch_no
;
4652 this->statement_list();
4653 statements
= this->gogo_
->finish_block(this->location());
4656 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH
))
4658 error_at(this->location(),
4659 "fallthrough is not permitted in a type switch");
4660 if (this->advance_token()->is_op(OPERATOR_SEMICOLON
))
4661 this->advance_token();
4666 go_assert(types
.empty());
4669 error_at(location
, "multiple defaults in type switch");
4672 *saw_default
= true;
4673 clauses
->add(NULL
, false, true, statements
, location
);
4675 else if (!types
.empty())
4677 for (std::vector
<Type
*>::const_iterator p
= types
.begin();
4678 p
+ 1 != types
.end();
4680 clauses
->add(*p
, true, false, NULL
, location
);
4681 clauses
->add(types
.back(), false, false, statements
, location
);
4684 clauses
->add(Type::make_error_type(), false, false, statements
, location
);
4687 // TypeSwitchCase = "case" type | "default"
4689 // We accept a comma separated list of types.
4692 Parse::type_switch_case(std::vector
<Type
*>* types
, bool* is_default
)
4694 const Token
* token
= this->peek_token();
4695 if (token
->is_keyword(KEYWORD_CASE
))
4697 this->advance_token();
4700 Type
* t
= this->type();
4702 if (!t
->is_error_type())
4703 types
->push_back(t
);
4706 this->gogo_
->mark_locals_used();
4707 token
= this->peek_token();
4708 while (!token
->is_op(OPERATOR_COLON
)
4709 && !token
->is_op(OPERATOR_COMMA
)
4710 && !token
->is_op(OPERATOR_RCURLY
)
4711 && !token
->is_eof())
4712 token
= this->advance_token();
4715 if (!this->peek_token()->is_op(OPERATOR_COMMA
))
4717 this->advance_token();
4720 else if (token
->is_keyword(KEYWORD_DEFAULT
))
4722 this->advance_token();
4727 error_at(this->location(), "expected %<case%> or %<default%>");
4728 if (!token
->is_op(OPERATOR_RCURLY
))
4729 this->advance_token();
4733 // SelectStat = "select" "{" { CommClause } "}" .
4736 Parse::select_stat(Label
* label
)
4738 go_assert(this->peek_token()->is_keyword(KEYWORD_SELECT
));
4739 Location location
= this->location();
4740 const Token
* token
= this->advance_token();
4742 if (!token
->is_op(OPERATOR_LCURLY
))
4744 Location token_loc
= token
->location();
4745 if (token
->is_op(OPERATOR_SEMICOLON
)
4746 && this->advance_token()->is_op(OPERATOR_LCURLY
))
4747 error_at(token_loc
, "unexpected semicolon or newline before %<{%>");
4750 error_at(this->location(), "expected %<{%>");
4754 this->advance_token();
4756 Select_statement
* statement
= Statement::make_select_statement(location
);
4758 this->push_break_statement(statement
, label
);
4760 Select_clauses
* select_clauses
= new Select_clauses();
4761 bool saw_default
= false;
4762 while (!this->peek_token()->is_op(OPERATOR_RCURLY
))
4764 if (this->peek_token()->is_eof())
4766 error_at(this->location(), "expected %<}%>");
4769 this->comm_clause(select_clauses
, &saw_default
);
4772 this->advance_token();
4774 statement
->add_clauses(select_clauses
);
4776 this->pop_break_statement();
4778 this->gogo_
->add_statement(statement
);
4781 // CommClause = CommCase ":" { Statement ";" } .
4784 Parse::comm_clause(Select_clauses
* clauses
, bool* saw_default
)
4786 Location location
= this->location();
4787 bool is_send
= false;
4788 Expression
* channel
= NULL
;
4789 Expression
* val
= NULL
;
4790 Expression
* closed
= NULL
;
4791 std::string varname
;
4792 std::string closedname
;
4793 bool is_default
= false;
4794 bool got_case
= this->comm_case(&is_send
, &channel
, &val
, &closed
,
4795 &varname
, &closedname
, &is_default
);
4799 && closedname
.empty()
4801 && val
->index_expression() != NULL
)
4802 val
->index_expression()->set_is_lvalue();
4804 if (this->peek_token()->is_op(OPERATOR_COLON
))
4805 this->advance_token();
4807 error_at(this->location(), "expected colon");
4809 this->gogo_
->start_block(this->location());
4811 Named_object
* var
= NULL
;
4812 if (!varname
.empty())
4814 // FIXME: LOCATION is slightly wrong here.
4815 Variable
* v
= new Variable(NULL
, channel
, false, false, false,
4817 v
->set_type_from_chan_element();
4818 var
= this->gogo_
->add_variable(varname
, v
);
4821 Named_object
* closedvar
= NULL
;
4822 if (!closedname
.empty())
4824 // FIXME: LOCATION is slightly wrong here.
4825 Variable
* v
= new Variable(Type::lookup_bool_type(), NULL
,
4826 false, false, false, location
);
4827 closedvar
= this->gogo_
->add_variable(closedname
, v
);
4830 this->statement_list();
4832 Block
* statements
= this->gogo_
->finish_block(this->location());
4838 error_at(location
, "multiple defaults in select");
4841 *saw_default
= true;
4845 clauses
->add(is_send
, channel
, val
, closed
, var
, closedvar
, is_default
,
4846 statements
, location
);
4847 else if (statements
!= NULL
)
4849 // Add the statements to make sure that any names they define
4851 this->gogo_
->add_block(statements
, location
);
4855 // CommCase = "case" ( SendStmt | RecvStmt ) | "default" .
4858 Parse::comm_case(bool* is_send
, Expression
** channel
, Expression
** val
,
4859 Expression
** closed
, std::string
* varname
,
4860 std::string
* closedname
, bool* is_default
)
4862 const Token
* token
= this->peek_token();
4863 if (token
->is_keyword(KEYWORD_DEFAULT
))
4865 this->advance_token();
4868 else if (token
->is_keyword(KEYWORD_CASE
))
4870 this->advance_token();
4871 if (!this->send_or_recv_stmt(is_send
, channel
, val
, closed
, varname
,
4877 error_at(this->location(), "expected %<case%> or %<default%>");
4878 if (!token
->is_op(OPERATOR_RCURLY
))
4879 this->advance_token();
4886 // RecvStmt = [ Expression [ "," Expression ] ( "=" | ":=" ) ] RecvExpr .
4887 // RecvExpr = Expression .
4890 Parse::send_or_recv_stmt(bool* is_send
, Expression
** channel
, Expression
** val
,
4891 Expression
** closed
, std::string
* varname
,
4892 std::string
* closedname
)
4894 const Token
* token
= this->peek_token();
4895 bool saw_comma
= false;
4896 bool closed_is_id
= false;
4897 if (token
->is_identifier())
4899 Gogo
* gogo
= this->gogo_
;
4900 std::string recv_var
= token
->identifier();
4901 bool is_rv_exported
= token
->is_identifier_exported();
4902 Location recv_var_loc
= token
->location();
4903 token
= this->advance_token();
4904 if (token
->is_op(OPERATOR_COLONEQ
))
4907 this->advance_token();
4908 Expression
* e
= this->expression(PRECEDENCE_NORMAL
, false, false,
4910 Receive_expression
* re
= e
->receive_expression();
4913 if (!e
->is_error_expression())
4914 error_at(this->location(), "expected receive expression");
4917 if (recv_var
== "_")
4919 error_at(recv_var_loc
,
4920 "no new variables on left side of %<:=%>");
4921 recv_var
= Gogo::erroneous_name();
4924 *varname
= gogo
->pack_hidden_name(recv_var
, is_rv_exported
);
4925 *channel
= re
->channel();
4928 else if (token
->is_op(OPERATOR_COMMA
))
4930 token
= this->advance_token();
4931 if (token
->is_identifier())
4933 std::string recv_closed
= token
->identifier();
4934 bool is_rc_exported
= token
->is_identifier_exported();
4935 Location recv_closed_loc
= token
->location();
4936 closed_is_id
= true;
4938 token
= this->advance_token();
4939 if (token
->is_op(OPERATOR_COLONEQ
))
4941 // case rv, rc := <-c:
4942 this->advance_token();
4943 Expression
* e
= this->expression(PRECEDENCE_NORMAL
, false,
4945 Receive_expression
* re
= e
->receive_expression();
4948 if (!e
->is_error_expression())
4949 error_at(this->location(),
4950 "expected receive expression");
4953 if (recv_var
== "_" && recv_closed
== "_")
4955 error_at(recv_var_loc
,
4956 "no new variables on left side of %<:=%>");
4957 recv_var
= Gogo::erroneous_name();
4960 if (recv_var
!= "_")
4961 *varname
= gogo
->pack_hidden_name(recv_var
,
4963 if (recv_closed
!= "_")
4964 *closedname
= gogo
->pack_hidden_name(recv_closed
,
4966 *channel
= re
->channel();
4970 this->unget_token(Token::make_identifier_token(recv_closed
,
4975 *val
= this->id_to_expression(gogo
->pack_hidden_name(recv_var
,
4977 recv_var_loc
, true);
4981 this->unget_token(Token::make_identifier_token(recv_var
,
4986 // If SAW_COMMA is false, then we are looking at the start of the
4987 // send or receive expression. If SAW_COMMA is true, then *VAL is
4988 // set and we just read a comma.
4991 if (saw_comma
|| !this->peek_token()->is_op(OPERATOR_CHANOP
))
4992 e
= this->expression(PRECEDENCE_NORMAL
, true, true, NULL
, NULL
);
4997 this->advance_token();
4998 *channel
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
5000 // The next token should be ':'. If it is '<-', then we have
5002 // which is to say, send on a channel received from a channel.
5003 if (!this->peek_token()->is_op(OPERATOR_CHANOP
))
5006 e
= Expression::make_receive(*channel
, (*channel
)->location());
5009 if (this->peek_token()->is_op(OPERATOR_EQ
))
5011 if (!this->advance_token()->is_op(OPERATOR_CHANOP
))
5013 error_at(this->location(), "missing %<<-%>");
5017 this->advance_token();
5018 *channel
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
5022 // *VAL is already set.
5023 if (!e
->is_sink_expression())
5029 if (!e
->is_sink_expression())
5038 error_at(this->location(), "expected %<=%> or %<:=%>");
5040 error_at(this->location(), "expected %<=%>");
5044 if (this->peek_token()->is_op(OPERATOR_CHANOP
))
5048 *channel
= this->verify_not_sink(e
);
5049 this->advance_token();
5050 *val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
5054 error_at(this->location(), "expected %<<-%> or %<=%>");
5058 // ForStat = "for" [ Condition | ForClause | RangeClause ] Block .
5059 // Condition = Expression .
5062 Parse::for_stat(Label
* label
)
5064 go_assert(this->peek_token()->is_keyword(KEYWORD_FOR
));
5065 Location location
= this->location();
5066 const Token
* token
= this->advance_token();
5068 // Open a block to hold any variables defined in the init statement
5069 // of the for statement.
5070 this->gogo_
->start_block(location
);
5073 Expression
* cond
= NULL
;
5075 Range_clause range_clause
;
5077 if (!token
->is_op(OPERATOR_LCURLY
))
5079 if (token
->is_keyword(KEYWORD_VAR
))
5081 error_at(this->location(),
5082 "var declaration not allowed in for initializer");
5086 if (token
->is_op(OPERATOR_SEMICOLON
))
5087 this->for_clause(&cond
, &post
);
5090 // We might be looking at a Condition, an InitStat, or a
5093 cond
= this->simple_stat(false, &saw_send_stmt
, &range_clause
, NULL
);
5094 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5096 if (cond
== NULL
&& !range_clause
.found
)
5099 error_at(this->location(),
5100 ("send statement used as value; "
5101 "use select for non-blocking send"));
5103 error_at(this->location(), "parse error in for statement");
5108 if (range_clause
.found
)
5109 error_at(this->location(), "parse error after range clause");
5113 // COND is actually an expression statement for
5114 // InitStat at the start of a ForClause.
5115 this->expression_stat(cond
);
5119 this->for_clause(&cond
, &post
);
5124 // Check for the easy error of a newline before starting the block.
5125 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5127 Location semi_loc
= this->location();
5128 if (this->advance_token()->is_op(OPERATOR_LCURLY
))
5129 error_at(semi_loc
, "missing %<{%> after for clause");
5130 // Otherwise we will get an error when we call this->block
5134 // Build the For_statement and note that it is the current target
5135 // for break and continue statements.
5137 For_statement
* sfor
;
5138 For_range_statement
* srange
;
5140 if (!range_clause
.found
)
5142 sfor
= Statement::make_for_statement(init
, cond
, post
, location
);
5148 srange
= Statement::make_for_range_statement(range_clause
.index
,
5156 this->push_break_statement(s
, label
);
5157 this->push_continue_statement(s
, label
);
5159 // Gather the block of statements in the loop and add them to the
5162 this->gogo_
->start_block(this->location());
5163 Location end_loc
= this->block();
5164 Block
* statements
= this->gogo_
->finish_block(end_loc
);
5167 sfor
->add_statements(statements
);
5169 srange
->add_statements(statements
);
5171 // This is no longer the break/continue target.
5172 this->pop_break_statement();
5173 this->pop_continue_statement();
5175 // Add the For_statement to the list of statements, and close out
5176 // the block we started to hold any variables defined in the for
5179 this->gogo_
->add_statement(s
);
5181 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
5185 // ForClause = [ InitStat ] ";" [ Condition ] ";" [ PostStat ] .
5186 // InitStat = SimpleStat .
5187 // PostStat = SimpleStat .
5189 // We have already read InitStat at this point.
5192 Parse::for_clause(Expression
** cond
, Block
** post
)
5194 go_assert(this->peek_token()->is_op(OPERATOR_SEMICOLON
));
5195 this->advance_token();
5196 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5198 else if (this->peek_token()->is_op(OPERATOR_LCURLY
))
5200 error_at(this->location(), "missing %<{%> after for clause");
5206 *cond
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
5207 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5208 error_at(this->location(), "expected semicolon");
5210 this->advance_token();
5212 if (this->peek_token()->is_op(OPERATOR_LCURLY
))
5216 this->gogo_
->start_block(this->location());
5217 this->simple_stat(false, NULL
, NULL
, NULL
);
5218 *post
= this->gogo_
->finish_block(this->location());
5222 // RangeClause = [ IdentifierList ( "=" | ":=" ) ] "range" Expression .
5224 // This is the := version. It is called with a list of identifiers.
5227 Parse::range_clause_decl(const Typed_identifier_list
* til
,
5228 Range_clause
* p_range_clause
)
5230 go_assert(this->peek_token()->is_keyword(KEYWORD_RANGE
));
5231 Location location
= this->location();
5233 p_range_clause
->found
= true;
5235 if (til
->size() > 2)
5236 error_at(this->location(), "too many variables for range clause");
5238 this->advance_token();
5239 Expression
* expr
= this->expression(PRECEDENCE_NORMAL
, false, false, NULL
,
5241 p_range_clause
->range
= expr
;
5246 bool any_new
= false;
5248 const Typed_identifier
* pti
= &til
->front();
5249 Named_object
* no
= this->init_var(*pti
, NULL
, expr
, true, true, &any_new
,
5251 if (any_new
&& no
->is_variable())
5252 no
->var_value()->set_type_from_range_index();
5253 p_range_clause
->index
= Expression::make_var_reference(no
, location
);
5255 if (til
->size() == 1)
5256 p_range_clause
->value
= NULL
;
5260 bool is_new
= false;
5261 no
= this->init_var(*pti
, NULL
, expr
, true, true, &is_new
, NULL
, NULL
);
5262 if (is_new
&& no
->is_variable())
5263 no
->var_value()->set_type_from_range_value();
5266 if (!Gogo::is_sink_name(pti
->name()))
5267 p_range_clause
->value
= Expression::make_var_reference(no
, location
);
5271 error_at(location
, "variables redeclared but no variable is new");
5274 // The = version of RangeClause. This is called with a list of
5278 Parse::range_clause_expr(const Expression_list
* vals
,
5279 Range_clause
* p_range_clause
)
5281 go_assert(this->peek_token()->is_keyword(KEYWORD_RANGE
));
5283 p_range_clause
->found
= true;
5285 go_assert(vals
->size() >= 1);
5286 if (vals
->size() > 2)
5287 error_at(this->location(), "too many variables for range clause");
5289 this->advance_token();
5290 p_range_clause
->range
= this->expression(PRECEDENCE_NORMAL
, false, false,
5296 p_range_clause
->index
= vals
->front();
5297 if (vals
->size() == 1)
5298 p_range_clause
->value
= NULL
;
5300 p_range_clause
->value
= vals
->back();
5303 // Push a statement on the break stack.
5306 Parse::push_break_statement(Statement
* enclosing
, Label
* label
)
5308 if (this->break_stack_
== NULL
)
5309 this->break_stack_
= new Bc_stack();
5310 this->break_stack_
->push_back(std::make_pair(enclosing
, label
));
5313 // Push a statement on the continue stack.
5316 Parse::push_continue_statement(Statement
* enclosing
, Label
* label
)
5318 if (this->continue_stack_
== NULL
)
5319 this->continue_stack_
= new Bc_stack();
5320 this->continue_stack_
->push_back(std::make_pair(enclosing
, label
));
5323 // Pop the break stack.
5326 Parse::pop_break_statement()
5328 this->break_stack_
->pop_back();
5331 // Pop the continue stack.
5334 Parse::pop_continue_statement()
5336 this->continue_stack_
->pop_back();
5339 // Find a break or continue statement given a label name.
5342 Parse::find_bc_statement(const Bc_stack
* bc_stack
, const std::string
& label
)
5344 if (bc_stack
== NULL
)
5346 for (Bc_stack::const_reverse_iterator p
= bc_stack
->rbegin();
5347 p
!= bc_stack
->rend();
5350 if (p
->second
!= NULL
&& p
->second
->name() == label
)
5352 p
->second
->set_is_used();
5359 // BreakStat = "break" [ identifier ] .
5364 go_assert(this->peek_token()->is_keyword(KEYWORD_BREAK
));
5365 Location location
= this->location();
5367 const Token
* token
= this->advance_token();
5368 Statement
* enclosing
;
5369 if (!token
->is_identifier())
5371 if (this->break_stack_
== NULL
|| this->break_stack_
->empty())
5373 error_at(this->location(),
5374 "break statement not within for or switch or select");
5377 enclosing
= this->break_stack_
->back().first
;
5381 enclosing
= this->find_bc_statement(this->break_stack_
,
5382 token
->identifier());
5383 if (enclosing
== NULL
)
5385 // If there is a label with this name, mark it as used to
5386 // avoid a useless error about an unused label.
5387 this->gogo_
->add_label_reference(token
->identifier(),
5388 Linemap::unknown_location(), false);
5390 error_at(token
->location(), "invalid break label %qs",
5391 Gogo::message_name(token
->identifier()).c_str());
5392 this->advance_token();
5395 this->advance_token();
5398 Unnamed_label
* label
;
5399 if (enclosing
->classification() == Statement::STATEMENT_FOR
)
5400 label
= enclosing
->for_statement()->break_label();
5401 else if (enclosing
->classification() == Statement::STATEMENT_FOR_RANGE
)
5402 label
= enclosing
->for_range_statement()->break_label();
5403 else if (enclosing
->classification() == Statement::STATEMENT_SWITCH
)
5404 label
= enclosing
->switch_statement()->break_label();
5405 else if (enclosing
->classification() == Statement::STATEMENT_TYPE_SWITCH
)
5406 label
= enclosing
->type_switch_statement()->break_label();
5407 else if (enclosing
->classification() == Statement::STATEMENT_SELECT
)
5408 label
= enclosing
->select_statement()->break_label();
5412 this->gogo_
->add_statement(Statement::make_break_statement(label
,
5416 // ContinueStat = "continue" [ identifier ] .
5419 Parse::continue_stat()
5421 go_assert(this->peek_token()->is_keyword(KEYWORD_CONTINUE
));
5422 Location location
= this->location();
5424 const Token
* token
= this->advance_token();
5425 Statement
* enclosing
;
5426 if (!token
->is_identifier())
5428 if (this->continue_stack_
== NULL
|| this->continue_stack_
->empty())
5430 error_at(this->location(), "continue statement not within for");
5433 enclosing
= this->continue_stack_
->back().first
;
5437 enclosing
= this->find_bc_statement(this->continue_stack_
,
5438 token
->identifier());
5439 if (enclosing
== NULL
)
5441 // If there is a label with this name, mark it as used to
5442 // avoid a useless error about an unused label.
5443 this->gogo_
->add_label_reference(token
->identifier(),
5444 Linemap::unknown_location(), false);
5446 error_at(token
->location(), "invalid continue label %qs",
5447 Gogo::message_name(token
->identifier()).c_str());
5448 this->advance_token();
5451 this->advance_token();
5454 Unnamed_label
* label
;
5455 if (enclosing
->classification() == Statement::STATEMENT_FOR
)
5456 label
= enclosing
->for_statement()->continue_label();
5457 else if (enclosing
->classification() == Statement::STATEMENT_FOR_RANGE
)
5458 label
= enclosing
->for_range_statement()->continue_label();
5462 this->gogo_
->add_statement(Statement::make_continue_statement(label
,
5466 // GotoStat = "goto" identifier .
5471 go_assert(this->peek_token()->is_keyword(KEYWORD_GOTO
));
5472 Location location
= this->location();
5473 const Token
* token
= this->advance_token();
5474 if (!token
->is_identifier())
5475 error_at(this->location(), "expected label for goto");
5478 Label
* label
= this->gogo_
->add_label_reference(token
->identifier(),
5480 Statement
* s
= Statement::make_goto_statement(label
, location
);
5481 this->gogo_
->add_statement(s
);
5482 this->advance_token();
5486 // PackageClause = "package" PackageName .
5489 Parse::package_clause()
5491 const Token
* token
= this->peek_token();
5492 Location location
= token
->location();
5494 if (!token
->is_keyword(KEYWORD_PACKAGE
))
5496 error_at(this->location(), "program must start with package clause");
5501 token
= this->advance_token();
5502 if (token
->is_identifier())
5504 name
= token
->identifier();
5507 error_at(this->location(), "invalid package name _");
5508 name
= Gogo::erroneous_name();
5510 this->advance_token();
5514 error_at(this->location(), "package name must be an identifier");
5518 this->gogo_
->set_package_name(name
, location
);
5521 // ImportDecl = "import" Decl<ImportSpec> .
5524 Parse::import_decl()
5526 go_assert(this->peek_token()->is_keyword(KEYWORD_IMPORT
));
5527 this->advance_token();
5528 this->decl(&Parse::import_spec
, NULL
);
5531 // ImportSpec = [ "." | PackageName ] PackageFileName .
5534 Parse::import_spec(void*)
5536 const Token
* token
= this->peek_token();
5537 Location location
= token
->location();
5539 std::string local_name
;
5540 bool is_local_name_exported
= false;
5541 if (token
->is_op(OPERATOR_DOT
))
5544 token
= this->advance_token();
5546 else if (token
->is_identifier())
5548 local_name
= token
->identifier();
5549 is_local_name_exported
= token
->is_identifier_exported();
5550 token
= this->advance_token();
5553 if (!token
->is_string())
5555 error_at(this->location(), "import statement not a string");
5556 this->advance_token();
5560 this->gogo_
->import_package(token
->string_value(), local_name
,
5561 is_local_name_exported
, location
);
5563 this->advance_token();
5566 // SourceFile = PackageClause ";" { ImportDecl ";" }
5567 // { TopLevelDecl ";" } .
5572 this->package_clause();
5574 const Token
* token
= this->peek_token();
5575 if (token
->is_op(OPERATOR_SEMICOLON
))
5576 token
= this->advance_token();
5578 error_at(this->location(),
5579 "expected %<;%> or newline after package clause");
5581 while (token
->is_keyword(KEYWORD_IMPORT
))
5583 this->import_decl();
5584 token
= this->peek_token();
5585 if (token
->is_op(OPERATOR_SEMICOLON
))
5586 token
= this->advance_token();
5588 error_at(this->location(),
5589 "expected %<;%> or newline after import declaration");
5592 while (!token
->is_eof())
5594 if (this->declaration_may_start_here())
5595 this->declaration();
5598 error_at(this->location(), "expected declaration");
5599 this->gogo_
->mark_locals_used();
5601 this->advance_token();
5602 while (!this->peek_token()->is_eof()
5603 && !this->peek_token()->is_op(OPERATOR_SEMICOLON
)
5604 && !this->peek_token()->is_op(OPERATOR_RCURLY
));
5605 if (!this->peek_token()->is_eof()
5606 && !this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5607 this->advance_token();
5609 token
= this->peek_token();
5610 if (token
->is_op(OPERATOR_SEMICOLON
))
5611 token
= this->advance_token();
5612 else if (!token
->is_eof() || !saw_errors())
5614 if (token
->is_op(OPERATOR_CHANOP
))
5615 error_at(this->location(),
5616 ("send statement used as value; "
5617 "use select for non-blocking send"));
5619 error_at(this->location(),
5620 "expected %<;%> or newline after top level declaration");
5621 this->skip_past_error(OPERATOR_INVALID
);
5626 // Reset the current iota value.
5634 // Return the current iota value.
5642 // Increment the current iota value.
5645 Parse::increment_iota()
5650 // Skip forward to a semicolon or OP. OP will normally be
5651 // OPERATOR_RPAREN or OPERATOR_RCURLY. If we find a semicolon, move
5652 // past it and return. If we find OP, it will be the next token to
5653 // read. Return true if we are OK, false if we found EOF.
5656 Parse::skip_past_error(Operator op
)
5658 this->gogo_
->mark_locals_used();
5659 const Token
* token
= this->peek_token();
5660 while (!token
->is_op(op
))
5662 if (token
->is_eof())
5664 if (token
->is_op(OPERATOR_SEMICOLON
))
5666 this->advance_token();
5669 token
= this->advance_token();
5674 // Check that an expression is not a sink.
5677 Parse::verify_not_sink(Expression
* expr
)
5679 if (expr
->is_sink_expression())
5681 error_at(expr
->location(), "cannot use _ as value");
5682 expr
= Expression::make_error(expr
->location());
5685 // If this can not be a sink, and it is a variable, then we are
5686 // using the variable, not just assigning to it.
5687 Var_expression
* ve
= expr
->var_expression();
5689 this->mark_var_used(ve
->named_object());
5694 // Mark a variable as used.
5697 Parse::mark_var_used(Named_object
* no
)
5699 if (no
->is_variable())
5701 no
->var_value()->set_is_used();
5703 // When a type switch uses := to define a variable, then for
5704 // each case with a single type we introduce a new variable with
5705 // the appropriate type. When we do, if the newly introduced
5706 // variable is used, then the type switch variable is used.
5707 Type_switch_vars::iterator p
= this->type_switch_vars_
.find(no
);
5708 if (p
!= this->type_switch_vars_
.end())
5709 p
->second
->var_value()->set_is_used();