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.
11 #include "go-diagnostics.h"
13 #include "statements.h"
14 #include "expressions.h"
17 // Struct Parse::Enclosing_var_comparison.
19 // Return true if v1 should be considered to be less than v2.
22 Parse::Enclosing_var_comparison::operator()(const Enclosing_var
& v1
,
23 const Enclosing_var
& v2
) const
25 if (v1
.var() == v2
.var())
28 const std::string
& n1(v1
.var()->name());
29 const std::string
& n2(v2
.var()->name());
30 int i
= n1
.compare(n2
);
36 // If we get here it means that a single nested function refers to
37 // two different variables defined in enclosing functions, and both
38 // variables have the same name. I think this is impossible.
44 Parse::Parse(Lex
* lex
, Gogo
* gogo
)
46 token_(Token::make_invalid_token(Linemap::unknown_location())),
47 unget_token_(Token::make_invalid_token(Linemap::unknown_location())),
48 unget_token_valid_(false),
49 is_erroneous_function_(false),
52 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 go_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 go_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 go_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()->note_usage(Gogo::unpack_hidden_name(name
));
204 token
= this->advance_token();
205 if (!token
->is_identifier())
207 go_error_at(this->location(), "expected identifier");
211 name
= token
->identifier();
215 go_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(true);
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 go_error_at(this->location(), "expected %<)%>");
279 go_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 go_error_at(location
,
334 "invalid reference to hidden type %<%s.%s%>",
335 Gogo::message_name(packname
).c_str(),
336 Gogo::message_name(name
).c_str());
343 if (named_object
== NULL
)
346 named_object
= this->gogo_
->add_unknown_name(name
, location
);
349 const std::string
& packname(package
->package_value()->package_name());
350 go_error_at(location
, "reference to undefined identifier %<%s.%s%>",
351 Gogo::message_name(packname
).c_str(),
352 Gogo::message_name(name
).c_str());
357 else if (named_object
->is_type())
359 if (!named_object
->type_value()->is_visible())
362 else if (named_object
->is_unknown() || named_object
->is_type_declaration())
370 go_error_at(location
, "expected type");
371 return Type::make_error_type();
374 if (named_object
->is_type())
375 return named_object
->type_value();
376 else if (named_object
->is_unknown() || named_object
->is_type_declaration())
377 return Type::make_forward_declaration(named_object
);
382 // ArrayType = "[" [ ArrayLength ] "]" ElementType .
383 // ArrayLength = Expression .
384 // ElementType = CompleteType .
387 Parse::array_type(bool may_use_ellipsis
)
389 go_assert(this->peek_token()->is_op(OPERATOR_LSQUARE
));
390 const Token
* token
= this->advance_token();
392 Expression
* length
= NULL
;
393 if (token
->is_op(OPERATOR_RSQUARE
))
394 this->advance_token();
397 if (!token
->is_op(OPERATOR_ELLIPSIS
))
398 length
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
399 else if (may_use_ellipsis
)
401 // An ellipsis is used in composite literals to represent a
402 // fixed array of the size of the number of elements. We
403 // use a length of nil to represent this, and change the
404 // length when parsing the composite literal.
405 length
= Expression::make_nil(this->location());
406 this->advance_token();
410 go_error_at(this->location(),
411 "use of %<[...]%> outside of array literal");
412 length
= Expression::make_error(this->location());
413 this->advance_token();
415 if (!this->peek_token()->is_op(OPERATOR_RSQUARE
))
417 go_error_at(this->location(), "expected %<]%>");
418 return Type::make_error_type();
420 this->advance_token();
423 Type
* element_type
= this->type();
424 if (element_type
->is_error_type())
425 return Type::make_error_type();
427 return Type::make_array_type(element_type
, length
);
430 // MapType = "map" "[" KeyType "]" ValueType .
431 // KeyType = CompleteType .
432 // ValueType = CompleteType .
437 Location location
= this->location();
438 go_assert(this->peek_token()->is_keyword(KEYWORD_MAP
));
439 if (!this->advance_token()->is_op(OPERATOR_LSQUARE
))
441 go_error_at(this->location(), "expected %<[%>");
442 return Type::make_error_type();
444 this->advance_token();
446 Type
* key_type
= this->type();
448 if (!this->peek_token()->is_op(OPERATOR_RSQUARE
))
450 go_error_at(this->location(), "expected %<]%>");
451 return Type::make_error_type();
453 this->advance_token();
455 Type
* value_type
= this->type();
457 if (key_type
->is_error_type() || value_type
->is_error_type())
458 return Type::make_error_type();
460 return Type::make_map_type(key_type
, value_type
, location
);
463 // StructType = "struct" "{" { FieldDecl ";" } "}" .
468 go_assert(this->peek_token()->is_keyword(KEYWORD_STRUCT
));
469 Location location
= this->location();
470 if (!this->advance_token()->is_op(OPERATOR_LCURLY
))
472 Location token_loc
= this->location();
473 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
474 && this->advance_token()->is_op(OPERATOR_LCURLY
))
475 go_error_at(token_loc
, "unexpected semicolon or newline before %<{%>");
478 go_error_at(this->location(), "expected %<{%>");
479 return Type::make_error_type();
482 this->advance_token();
484 Struct_field_list
* sfl
= new Struct_field_list
;
485 while (!this->peek_token()->is_op(OPERATOR_RCURLY
))
487 this->field_decl(sfl
);
488 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
489 this->advance_token();
490 else if (!this->peek_token()->is_op(OPERATOR_RCURLY
))
492 go_error_at(this->location(), "expected %<;%> or %<}%> or newline");
493 if (!this->skip_past_error(OPERATOR_RCURLY
))
494 return Type::make_error_type();
497 this->advance_token();
499 for (Struct_field_list::const_iterator pi
= sfl
->begin();
503 if (pi
->type()->is_error_type())
505 for (Struct_field_list::const_iterator pj
= pi
+ 1;
509 if (pi
->field_name() == pj
->field_name()
510 && !Gogo::is_sink_name(pi
->field_name()))
511 go_error_at(pi
->location(), "duplicate field name %<%s%>",
512 Gogo::message_name(pi
->field_name()).c_str());
516 return Type::make_struct_type(sfl
, location
);
519 // FieldDecl = (IdentifierList CompleteType | TypeName) [ Tag ] .
520 // Tag = string_lit .
523 Parse::field_decl(Struct_field_list
* sfl
)
525 const Token
* token
= this->peek_token();
526 Location location
= token
->location();
528 bool is_anonymous_pointer
;
529 if (token
->is_op(OPERATOR_MULT
))
532 is_anonymous_pointer
= true;
534 else if (token
->is_identifier())
536 std::string id
= token
->identifier();
537 bool is_id_exported
= token
->is_identifier_exported();
538 Location id_location
= token
->location();
539 token
= this->advance_token();
540 is_anonymous
= (token
->is_op(OPERATOR_SEMICOLON
)
541 || token
->is_op(OPERATOR_RCURLY
)
542 || token
->is_op(OPERATOR_DOT
)
543 || token
->is_string());
544 is_anonymous_pointer
= false;
545 this->unget_token(Token::make_identifier_token(id
, is_id_exported
,
550 go_error_at(this->location(), "expected field name");
551 this->gogo_
->mark_locals_used();
552 while (!token
->is_op(OPERATOR_SEMICOLON
)
553 && !token
->is_op(OPERATOR_RCURLY
)
555 token
= this->advance_token();
561 if (is_anonymous_pointer
)
563 this->advance_token();
564 if (!this->peek_token()->is_identifier())
566 go_error_at(this->location(), "expected field name");
567 this->gogo_
->mark_locals_used();
568 while (!token
->is_op(OPERATOR_SEMICOLON
)
569 && !token
->is_op(OPERATOR_RCURLY
)
571 token
= this->advance_token();
575 Type
* type
= this->type_name(true);
578 if (this->peek_token()->is_string())
580 tag
= this->peek_token()->string_value();
581 this->advance_token();
584 if (!type
->is_error_type())
586 if (is_anonymous_pointer
)
587 type
= Type::make_pointer_type(type
);
588 sfl
->push_back(Struct_field(Typed_identifier("", type
, location
)));
590 sfl
->back().set_tag(tag
);
595 Typed_identifier_list til
;
598 token
= this->peek_token();
599 if (!token
->is_identifier())
601 go_error_at(this->location(), "expected identifier");
605 this->gogo_
->pack_hidden_name(token
->identifier(),
606 token
->is_identifier_exported());
607 til
.push_back(Typed_identifier(name
, NULL
, token
->location()));
608 if (!this->advance_token()->is_op(OPERATOR_COMMA
))
610 this->advance_token();
613 Type
* type
= this->type();
616 if (this->peek_token()->is_string())
618 tag
= this->peek_token()->string_value();
619 this->advance_token();
622 for (Typed_identifier_list::iterator p
= til
.begin();
627 sfl
->push_back(Struct_field(*p
));
629 sfl
->back().set_tag(tag
);
634 // PointerType = "*" Type .
637 Parse::pointer_type()
639 go_assert(this->peek_token()->is_op(OPERATOR_MULT
));
640 this->advance_token();
641 Type
* type
= this->type();
642 if (type
->is_error_type())
644 return Type::make_pointer_type(type
);
647 // ChannelType = Channel | SendChannel | RecvChannel .
648 // Channel = "chan" ElementType .
649 // SendChannel = "chan" "<-" ElementType .
650 // RecvChannel = "<-" "chan" ElementType .
653 Parse::channel_type()
655 const Token
* token
= this->peek_token();
658 if (token
->is_op(OPERATOR_CHANOP
))
660 if (!this->advance_token()->is_keyword(KEYWORD_CHAN
))
662 go_error_at(this->location(), "expected %<chan%>");
663 return Type::make_error_type();
666 this->advance_token();
670 go_assert(token
->is_keyword(KEYWORD_CHAN
));
671 if (this->advance_token()->is_op(OPERATOR_CHANOP
))
674 this->advance_token();
678 // Better error messages for the common error of omitting the
679 // channel element type.
680 if (!this->type_may_start_here())
682 token
= this->peek_token();
683 if (token
->is_op(OPERATOR_RCURLY
))
684 go_error_at(this->location(), "unexpected %<}%> in channel type");
685 else if (token
->is_op(OPERATOR_RPAREN
))
686 go_error_at(this->location(), "unexpected %<)%> in channel type");
687 else if (token
->is_op(OPERATOR_COMMA
))
688 go_error_at(this->location(), "unexpected comma in channel type");
690 go_error_at(this->location(), "expected channel element type");
691 return Type::make_error_type();
694 Type
* element_type
= this->type();
695 return Type::make_channel_type(send
, receive
, element_type
);
698 // Give an error for a duplicate parameter or receiver name.
701 Parse::check_signature_names(const Typed_identifier_list
* params
,
704 for (Typed_identifier_list::const_iterator p
= params
->begin();
708 if (p
->name().empty() || Gogo::is_sink_name(p
->name()))
710 std::pair
<std::string
, const Typed_identifier
*> val
=
711 std::make_pair(p
->name(), &*p
);
712 std::pair
<Parse::Names::iterator
, bool> ins
= names
->insert(val
);
715 go_error_at(p
->location(), "redefinition of %qs",
716 Gogo::message_name(p
->name()).c_str());
717 go_inform(ins
.first
->second
->location(),
718 "previous definition of %qs was here",
719 Gogo::message_name(p
->name()).c_str());
724 // Signature = Parameters [ Result ] .
726 // RECEIVER is the receiver if there is one, or NULL. LOCATION is the
727 // location of the start of the type.
729 // This returns NULL on a parse error.
732 Parse::signature(Typed_identifier
* receiver
, Location location
)
734 bool is_varargs
= false;
735 Typed_identifier_list
* params
;
736 bool params_ok
= this->parameters(¶ms
, &is_varargs
);
738 Typed_identifier_list
* results
= NULL
;
739 if (this->peek_token()->is_op(OPERATOR_LPAREN
)
740 || this->type_may_start_here())
742 if (!this->result(&results
))
750 if (receiver
!= NULL
)
751 names
[receiver
->name()] = receiver
;
753 this->check_signature_names(params
, &names
);
755 this->check_signature_names(results
, &names
);
757 Function_type
* ret
= Type::make_function_type(receiver
, params
, results
,
760 ret
->set_is_varargs();
764 // Parameters = "(" [ ParameterList [ "," ] ] ")" .
766 // This returns false on a parse error.
769 Parse::parameters(Typed_identifier_list
** pparams
, bool* is_varargs
)
773 if (!this->peek_token()->is_op(OPERATOR_LPAREN
))
775 go_error_at(this->location(), "expected %<(%>");
779 Typed_identifier_list
* params
= NULL
;
780 bool saw_error
= false;
782 const Token
* token
= this->advance_token();
783 if (!token
->is_op(OPERATOR_RPAREN
))
785 params
= this->parameter_list(is_varargs
);
788 token
= this->peek_token();
791 // The optional trailing comma is picked up in parameter_list.
793 if (!token
->is_op(OPERATOR_RPAREN
))
795 go_error_at(this->location(), "expected %<)%>");
798 this->advance_token();
807 // ParameterList = ParameterDecl { "," ParameterDecl } .
809 // This sets *IS_VARARGS if the list ends with an ellipsis.
810 // IS_VARARGS will be NULL if varargs are not permitted.
812 // We pick up an optional trailing comma.
814 // This returns NULL if some error is seen.
816 Typed_identifier_list
*
817 Parse::parameter_list(bool* is_varargs
)
819 Location location
= this->location();
820 Typed_identifier_list
* ret
= new Typed_identifier_list();
822 bool saw_error
= false;
824 // If we see an identifier and then a comma, then we don't know
825 // whether we are looking at a list of identifiers followed by a
826 // type, or a list of types given by name. We have to do an
827 // arbitrary lookahead to figure it out.
829 bool parameters_have_names
;
830 const Token
* token
= this->peek_token();
831 if (!token
->is_identifier())
833 // This must be a type which starts with something like '*'.
834 parameters_have_names
= false;
838 std::string name
= token
->identifier();
839 bool is_exported
= token
->is_identifier_exported();
840 Location location
= token
->location();
841 token
= this->advance_token();
842 if (!token
->is_op(OPERATOR_COMMA
))
844 if (token
->is_op(OPERATOR_DOT
))
846 // This is a qualified identifier, which must turn out
848 parameters_have_names
= false;
850 else if (token
->is_op(OPERATOR_RPAREN
))
852 // A single identifier followed by a parenthesis must be
854 parameters_have_names
= false;
858 // An identifier followed by something other than a
859 // comma or a dot or a right parenthesis must be a
860 // parameter name followed by a type.
861 parameters_have_names
= true;
864 this->unget_token(Token::make_identifier_token(name
, is_exported
,
869 // An identifier followed by a comma may be the first in a
870 // list of parameter names followed by a type, or it may be
871 // the first in a list of types without parameter names. To
872 // find out we gather as many identifiers separated by
874 std::string id_name
= this->gogo_
->pack_hidden_name(name
,
876 ret
->push_back(Typed_identifier(id_name
, NULL
, location
));
877 bool just_saw_comma
= true;
878 while (this->advance_token()->is_identifier())
880 name
= this->peek_token()->identifier();
881 is_exported
= this->peek_token()->is_identifier_exported();
882 location
= this->peek_token()->location();
883 id_name
= this->gogo_
->pack_hidden_name(name
, is_exported
);
884 ret
->push_back(Typed_identifier(id_name
, NULL
, location
));
885 if (!this->advance_token()->is_op(OPERATOR_COMMA
))
887 just_saw_comma
= false;
894 // We saw ID1 "," ID2 "," followed by something which
895 // was not an identifier. We must be seeing the start
896 // of a type, and ID1 and ID2 must be types, and the
897 // parameters don't have names.
898 parameters_have_names
= false;
900 else if (this->peek_token()->is_op(OPERATOR_RPAREN
))
902 // We saw ID1 "," ID2 ")". ID1 and ID2 must be types,
903 // and the parameters don't have names.
904 parameters_have_names
= false;
906 else if (this->peek_token()->is_op(OPERATOR_DOT
))
908 // We saw ID1 "," ID2 ".". ID2 must be a package name,
909 // ID1 must be a type, and the parameters don't have
911 parameters_have_names
= false;
912 this->unget_token(Token::make_identifier_token(name
, is_exported
,
915 just_saw_comma
= true;
919 // We saw ID1 "," ID2 followed by something other than
920 // ",", ".", or ")". We must be looking at the start of
921 // a type, and ID1 and ID2 must be parameter names.
922 parameters_have_names
= true;
925 if (parameters_have_names
)
927 go_assert(!just_saw_comma
);
928 // We have just seen ID1, ID2 xxx.
930 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS
))
934 go_error_at(this->location(),
935 "%<...%> only permits one name");
937 this->advance_token();
940 for (size_t i
= 0; i
< ret
->size(); ++i
)
941 ret
->set_type(i
, type
);
942 if (!this->peek_token()->is_op(OPERATOR_COMMA
))
943 return saw_error
? NULL
: ret
;
944 if (this->advance_token()->is_op(OPERATOR_RPAREN
))
945 return saw_error
? NULL
: ret
;
949 Typed_identifier_list
* tret
= new Typed_identifier_list();
950 for (Typed_identifier_list::const_iterator p
= ret
->begin();
954 Named_object
* no
= this->gogo_
->lookup(p
->name(), NULL
);
957 no
= this->gogo_
->add_unknown_name(p
->name(),
961 type
= no
->type_value();
962 else if (no
->is_unknown() || no
->is_type_declaration())
963 type
= Type::make_forward_declaration(no
);
966 go_error_at(p
->location(), "expected %<%s%> to be a type",
967 Gogo::message_name(p
->name()).c_str());
969 type
= Type::make_error_type();
971 tret
->push_back(Typed_identifier("", type
, p
->location()));
976 || this->peek_token()->is_op(OPERATOR_RPAREN
))
977 return saw_error
? NULL
: ret
;
982 bool mix_error
= false;
983 this->parameter_decl(parameters_have_names
, ret
, is_varargs
, &mix_error
,
985 while (this->peek_token()->is_op(OPERATOR_COMMA
))
987 if (this->advance_token()->is_op(OPERATOR_RPAREN
))
989 if (is_varargs
!= NULL
&& *is_varargs
)
991 go_error_at(this->location(), "%<...%> must be last parameter");
994 this->parameter_decl(parameters_have_names
, ret
, is_varargs
, &mix_error
,
999 go_error_at(location
, "invalid named/anonymous mix");
1010 // ParameterDecl = [ IdentifierList ] [ "..." ] Type .
1013 Parse::parameter_decl(bool parameters_have_names
,
1014 Typed_identifier_list
* til
,
1019 if (!parameters_have_names
)
1022 Location location
= this->location();
1023 if (!this->peek_token()->is_identifier())
1025 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS
))
1026 type
= this->type();
1029 if (is_varargs
== NULL
)
1030 go_error_at(this->location(), "invalid use of %<...%>");
1033 this->advance_token();
1034 if (is_varargs
== NULL
1035 && this->peek_token()->is_op(OPERATOR_RPAREN
))
1036 type
= Type::make_error_type();
1039 Type
* element_type
= this->type();
1040 type
= Type::make_array_type(element_type
, NULL
);
1046 type
= this->type_name(false);
1047 if (type
->is_error_type()
1048 || (!this->peek_token()->is_op(OPERATOR_COMMA
)
1049 && !this->peek_token()->is_op(OPERATOR_RPAREN
)))
1052 while (!this->peek_token()->is_op(OPERATOR_COMMA
)
1053 && !this->peek_token()->is_op(OPERATOR_RPAREN
)
1054 && !this->peek_token()->is_eof())
1055 this->advance_token();
1058 if (!type
->is_error_type())
1059 til
->push_back(Typed_identifier("", type
, location
));
1065 size_t orig_count
= til
->size();
1066 if (this->peek_token()->is_identifier())
1067 this->identifier_list(til
);
1070 size_t new_count
= til
->size();
1073 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS
))
1074 type
= this->type();
1077 if (is_varargs
== NULL
)
1079 go_error_at(this->location(), "invalid use of %<...%>");
1082 else if (new_count
> orig_count
+ 1)
1084 go_error_at(this->location(), "%<...%> only permits one name");
1089 this->advance_token();
1090 Type
* element_type
= this->type();
1091 type
= Type::make_array_type(element_type
, NULL
);
1093 for (size_t i
= orig_count
; i
< new_count
; ++i
)
1094 til
->set_type(i
, type
);
1098 // Result = Parameters | Type .
1100 // This returns false on a parse error.
1103 Parse::result(Typed_identifier_list
** presults
)
1105 if (this->peek_token()->is_op(OPERATOR_LPAREN
))
1106 return this->parameters(presults
, NULL
);
1109 Location location
= this->location();
1110 Type
* type
= this->type();
1111 if (type
->is_error_type())
1116 Typed_identifier_list
* til
= new Typed_identifier_list();
1117 til
->push_back(Typed_identifier("", type
, location
));
1123 // Block = "{" [ StatementList ] "}" .
1125 // Returns the location of the closing brace.
1130 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
1132 Location loc
= this->location();
1133 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1134 && this->advance_token()->is_op(OPERATOR_LCURLY
))
1135 go_error_at(loc
, "unexpected semicolon or newline before %<{%>");
1138 go_error_at(this->location(), "expected %<{%>");
1139 return Linemap::unknown_location();
1143 const Token
* token
= this->advance_token();
1145 if (!token
->is_op(OPERATOR_RCURLY
))
1147 this->statement_list();
1148 token
= this->peek_token();
1149 if (!token
->is_op(OPERATOR_RCURLY
))
1151 if (!token
->is_eof() || !saw_errors())
1152 go_error_at(this->location(), "expected %<}%>");
1154 this->gogo_
->mark_locals_used();
1156 // Skip ahead to the end of the block, in hopes of avoiding
1157 // lots of meaningless errors.
1158 Location ret
= token
->location();
1160 while (!token
->is_eof())
1162 if (token
->is_op(OPERATOR_LCURLY
))
1164 else if (token
->is_op(OPERATOR_RCURLY
))
1169 this->advance_token();
1173 token
= this->advance_token();
1174 ret
= token
->location();
1180 Location ret
= token
->location();
1181 this->advance_token();
1185 // InterfaceType = "interface" "{" [ MethodSpecList ] "}" .
1186 // MethodSpecList = MethodSpec { ";" MethodSpec } [ ";" ] .
1189 Parse::interface_type(bool record
)
1191 go_assert(this->peek_token()->is_keyword(KEYWORD_INTERFACE
));
1192 Location location
= this->location();
1194 if (!this->advance_token()->is_op(OPERATOR_LCURLY
))
1196 Location token_loc
= this->location();
1197 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1198 && this->advance_token()->is_op(OPERATOR_LCURLY
))
1199 go_error_at(token_loc
, "unexpected semicolon or newline before %<{%>");
1202 go_error_at(this->location(), "expected %<{%>");
1203 return Type::make_error_type();
1206 this->advance_token();
1208 Typed_identifier_list
* methods
= new Typed_identifier_list();
1209 if (!this->peek_token()->is_op(OPERATOR_RCURLY
))
1211 this->method_spec(methods
);
1212 while (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
1214 if (this->advance_token()->is_op(OPERATOR_RCURLY
))
1216 this->method_spec(methods
);
1218 if (!this->peek_token()->is_op(OPERATOR_RCURLY
))
1220 go_error_at(this->location(), "expected %<}%>");
1221 while (!this->advance_token()->is_op(OPERATOR_RCURLY
))
1223 if (this->peek_token()->is_eof())
1224 return Type::make_error_type();
1228 this->advance_token();
1230 if (methods
->empty())
1236 Interface_type
* ret
;
1237 if (methods
== NULL
)
1238 ret
= Type::make_empty_interface_type(location
);
1240 ret
= Type::make_interface_type(methods
, location
);
1242 this->gogo_
->record_interface_type(ret
);
1246 // MethodSpec = MethodName Signature | InterfaceTypeName .
1247 // MethodName = identifier .
1248 // InterfaceTypeName = TypeName .
1251 Parse::method_spec(Typed_identifier_list
* methods
)
1253 const Token
* token
= this->peek_token();
1254 if (!token
->is_identifier())
1256 go_error_at(this->location(), "expected identifier");
1260 std::string name
= token
->identifier();
1261 bool is_exported
= token
->is_identifier_exported();
1262 Location location
= token
->location();
1264 if (this->advance_token()->is_op(OPERATOR_LPAREN
))
1266 // This is a MethodName.
1268 go_error_at(this->location(),
1269 "methods must have a unique non-blank name");
1270 name
= this->gogo_
->pack_hidden_name(name
, is_exported
);
1271 Type
* type
= this->signature(NULL
, location
);
1274 methods
->push_back(Typed_identifier(name
, type
, location
));
1278 this->unget_token(Token::make_identifier_token(name
, is_exported
,
1280 Type
* type
= this->type_name(false);
1281 if (type
->is_error_type()
1282 || (!this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1283 && !this->peek_token()->is_op(OPERATOR_RCURLY
)))
1285 if (this->peek_token()->is_op(OPERATOR_COMMA
))
1286 go_error_at(this->location(),
1287 "name list not allowed in interface type");
1289 go_error_at(location
, "expected signature or type name");
1290 this->gogo_
->mark_locals_used();
1291 token
= this->peek_token();
1292 while (!token
->is_eof()
1293 && !token
->is_op(OPERATOR_SEMICOLON
)
1294 && !token
->is_op(OPERATOR_RCURLY
))
1295 token
= this->advance_token();
1298 // This must be an interface type, but we can't check that now.
1299 // We check it and pull out the methods in
1300 // Interface_type::do_verify.
1301 methods
->push_back(Typed_identifier("", type
, location
));
1305 // Declaration = ConstDecl | TypeDecl | VarDecl | FunctionDecl | MethodDecl .
1308 Parse::declaration()
1310 const Token
* token
= this->peek_token();
1312 unsigned int pragmas
= this->lex_
->get_and_clear_pragmas();
1314 && !token
->is_keyword(KEYWORD_FUNC
)
1315 && !token
->is_keyword(KEYWORD_TYPE
))
1316 go_warning_at(token
->location(), 0,
1317 "ignoring magic comment before non-function");
1319 if (token
->is_keyword(KEYWORD_CONST
))
1321 else if (token
->is_keyword(KEYWORD_TYPE
))
1322 this->type_decl(pragmas
);
1323 else if (token
->is_keyword(KEYWORD_VAR
))
1325 else if (token
->is_keyword(KEYWORD_FUNC
))
1326 this->function_decl(pragmas
);
1329 go_error_at(this->location(), "expected declaration");
1330 this->advance_token();
1335 Parse::declaration_may_start_here()
1337 const Token
* token
= this->peek_token();
1338 return (token
->is_keyword(KEYWORD_CONST
)
1339 || token
->is_keyword(KEYWORD_TYPE
)
1340 || token
->is_keyword(KEYWORD_VAR
)
1341 || token
->is_keyword(KEYWORD_FUNC
));
1344 // Decl<P> = P | "(" [ List<P> ] ")" .
1347 Parse::decl(void (Parse::*pfn
)(void*, unsigned int), void* varg
,
1348 unsigned int pragmas
)
1350 if (this->peek_token()->is_eof())
1353 go_error_at(this->location(), "unexpected end of file");
1357 if (!this->peek_token()->is_op(OPERATOR_LPAREN
))
1358 (this->*pfn
)(varg
, pragmas
);
1362 go_warning_at(this->location(), 0,
1363 "ignoring magic //go:... comment before group");
1364 if (!this->advance_token()->is_op(OPERATOR_RPAREN
))
1366 this->list(pfn
, varg
, true);
1367 if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
1369 go_error_at(this->location(), "missing %<)%>");
1370 while (!this->advance_token()->is_op(OPERATOR_RPAREN
))
1372 if (this->peek_token()->is_eof())
1377 this->advance_token();
1381 // List<P> = P { ";" P } [ ";" ] .
1383 // In order to pick up the trailing semicolon we need to know what
1384 // might follow. This is either a '}' or a ')'.
1387 Parse::list(void (Parse::*pfn
)(void*, unsigned int), void* varg
,
1388 bool follow_is_paren
)
1390 (this->*pfn
)(varg
, 0);
1391 Operator follow
= follow_is_paren
? OPERATOR_RPAREN
: OPERATOR_RCURLY
;
1392 while (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1393 || this->peek_token()->is_op(OPERATOR_COMMA
))
1395 if (this->peek_token()->is_op(OPERATOR_COMMA
))
1396 go_error_at(this->location(), "unexpected comma");
1397 if (this->advance_token()->is_op(follow
))
1399 (this->*pfn
)(varg
, 0);
1403 // ConstDecl = "const" ( ConstSpec | "(" { ConstSpec ";" } ")" ) .
1408 go_assert(this->peek_token()->is_keyword(KEYWORD_CONST
));
1409 this->advance_token();
1412 Type
* last_type
= NULL
;
1413 Expression_list
* last_expr_list
= NULL
;
1415 if (!this->peek_token()->is_op(OPERATOR_LPAREN
))
1416 this->const_spec(&last_type
, &last_expr_list
);
1419 this->advance_token();
1420 while (!this->peek_token()->is_op(OPERATOR_RPAREN
))
1422 this->const_spec(&last_type
, &last_expr_list
);
1423 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
1424 this->advance_token();
1425 else if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
1427 go_error_at(this->location(),
1428 "expected %<;%> or %<)%> or newline");
1429 if (!this->skip_past_error(OPERATOR_RPAREN
))
1433 this->advance_token();
1436 if (last_expr_list
!= NULL
)
1437 delete last_expr_list
;
1440 // ConstSpec = IdentifierList [ [ CompleteType ] "=" ExpressionList ] .
1443 Parse::const_spec(Type
** last_type
, Expression_list
** last_expr_list
)
1445 Typed_identifier_list til
;
1446 this->identifier_list(&til
);
1449 if (this->type_may_start_here())
1451 type
= this->type();
1453 *last_expr_list
= NULL
;
1456 Expression_list
*expr_list
;
1457 if (!this->peek_token()->is_op(OPERATOR_EQ
))
1459 if (*last_expr_list
== NULL
)
1461 go_error_at(this->location(), "expected %<=%>");
1465 expr_list
= new Expression_list
;
1466 for (Expression_list::const_iterator p
= (*last_expr_list
)->begin();
1467 p
!= (*last_expr_list
)->end();
1469 expr_list
->push_back((*p
)->copy());
1473 this->advance_token();
1474 expr_list
= this->expression_list(NULL
, false, true);
1476 if (*last_expr_list
!= NULL
)
1477 delete *last_expr_list
;
1478 *last_expr_list
= expr_list
;
1481 Expression_list::const_iterator pe
= expr_list
->begin();
1482 for (Typed_identifier_list::iterator pi
= til
.begin();
1486 if (pe
== expr_list
->end())
1488 go_error_at(this->location(), "not enough initializers");
1494 if (!Gogo::is_sink_name(pi
->name()))
1495 this->gogo_
->add_constant(*pi
, *pe
, this->iota_value());
1500 snprintf(buf
, sizeof buf
, ".$sinkconst%d", count
);
1502 Typed_identifier
ti(std::string(buf
), type
, pi
->location());
1503 Named_object
* no
= this->gogo_
->add_constant(ti
, *pe
, this->iota_value());
1504 no
->const_value()->set_is_sink();
1507 if (pe
!= expr_list
->end())
1508 go_error_at(this->location(), "too many initializers");
1510 this->increment_iota();
1515 // TypeDecl = "type" Decl<TypeSpec> .
1518 Parse::type_decl(unsigned int pragmas
)
1520 go_assert(this->peek_token()->is_keyword(KEYWORD_TYPE
));
1521 this->advance_token();
1522 this->decl(&Parse::type_spec
, NULL
, pragmas
);
1525 // TypeSpec = identifier ["="] Type .
1528 Parse::type_spec(void*, unsigned int pragmas
)
1530 const Token
* token
= this->peek_token();
1531 if (!token
->is_identifier())
1533 go_error_at(this->location(), "expected identifier");
1536 std::string name
= token
->identifier();
1537 bool is_exported
= token
->is_identifier_exported();
1538 Location location
= token
->location();
1539 token
= this->advance_token();
1541 bool is_alias
= false;
1542 if (token
->is_op(OPERATOR_EQ
))
1545 token
= this->advance_token();
1548 // The scope of the type name starts at the point where the
1549 // identifier appears in the source code. We implement this by
1550 // declaring the type before we read the type definition.
1551 Named_object
* named_type
= NULL
;
1554 name
= this->gogo_
->pack_hidden_name(name
, is_exported
);
1555 named_type
= this->gogo_
->declare_type(name
, location
);
1559 if (name
== "_" && token
->is_keyword(KEYWORD_INTERFACE
))
1561 // We call Parse::interface_type explicity here because we do not want
1562 // to record an interface with a blank type name.
1563 type
= this->interface_type(false);
1565 else if (!token
->is_op(OPERATOR_SEMICOLON
))
1566 type
= this->type();
1569 go_error_at(this->location(),
1570 "unexpected semicolon or newline in type declaration");
1571 type
= Type::make_error_type();
1572 this->advance_token();
1575 if (type
->is_error_type())
1577 this->gogo_
->mark_locals_used();
1578 while (!this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1579 && !this->peek_token()->is_eof())
1580 this->advance_token();
1585 if (named_type
->is_type_declaration())
1587 Type
* ftype
= type
->forwarded();
1588 if (ftype
->forward_declaration_type() != NULL
1589 && (ftype
->forward_declaration_type()->named_object()
1592 go_error_at(location
, "invalid recursive type");
1593 type
= Type::make_error_type();
1596 Named_type
* nt
= Type::make_named_type(named_type
, type
, location
);
1600 this->gogo_
->define_type(named_type
, nt
);
1601 go_assert(named_type
->package() == NULL
);
1603 if ((pragmas
& GOPRAGMA_NOTINHEAP
) != 0)
1605 nt
->set_not_in_heap();
1606 pragmas
&= ~GOPRAGMA_NOTINHEAP
;
1609 go_warning_at(location
, 0,
1610 "ignoring magic //go:... comment before type");
1614 // This will probably give a redefinition error.
1615 this->gogo_
->add_type(name
, type
, location
);
1620 // VarDecl = "var" Decl<VarSpec> .
1625 go_assert(this->peek_token()->is_keyword(KEYWORD_VAR
));
1626 this->advance_token();
1627 this->decl(&Parse::var_spec
, NULL
, 0);
1630 // VarSpec = IdentifierList
1631 // ( CompleteType [ "=" ExpressionList ] | "=" ExpressionList ) .
1634 Parse::var_spec(void*, unsigned int pragmas
)
1637 go_warning_at(this->location(), 0,
1638 "ignoring magic //go:... comment before var");
1640 // Get the variable names.
1641 Typed_identifier_list til
;
1642 this->identifier_list(&til
);
1644 Location location
= this->location();
1647 Expression_list
* init
= NULL
;
1648 if (!this->peek_token()->is_op(OPERATOR_EQ
))
1650 type
= this->type();
1651 if (type
->is_error_type())
1653 this->gogo_
->mark_locals_used();
1654 while (!this->peek_token()->is_op(OPERATOR_EQ
)
1655 && !this->peek_token()->is_op(OPERATOR_SEMICOLON
)
1656 && !this->peek_token()->is_eof())
1657 this->advance_token();
1659 if (this->peek_token()->is_op(OPERATOR_EQ
))
1661 this->advance_token();
1662 init
= this->expression_list(NULL
, false, true);
1667 this->advance_token();
1668 init
= this->expression_list(NULL
, false, true);
1671 this->init_vars(&til
, type
, init
, false, location
);
1677 // Create variables. TIL is a list of variable names. If TYPE is not
1678 // NULL, it is the type of all the variables. If INIT is not NULL, it
1679 // is an initializer list for the variables.
1682 Parse::init_vars(const Typed_identifier_list
* til
, Type
* type
,
1683 Expression_list
* init
, bool is_coloneq
,
1686 // Check for an initialization which can yield multiple values.
1687 if (init
!= NULL
&& init
->size() == 1 && til
->size() > 1)
1689 if (this->init_vars_from_call(til
, type
, *init
->begin(), is_coloneq
,
1692 if (this->init_vars_from_map(til
, type
, *init
->begin(), is_coloneq
,
1695 if (this->init_vars_from_receive(til
, type
, *init
->begin(), is_coloneq
,
1698 if (this->init_vars_from_type_guard(til
, type
, *init
->begin(),
1699 is_coloneq
, location
))
1703 if (init
!= NULL
&& init
->size() != til
->size())
1705 if (init
->empty() || !init
->front()->is_error_expression())
1706 go_error_at(location
, "wrong number of initializations");
1709 type
= Type::make_error_type();
1712 // Note that INIT was already parsed with the old name bindings, so
1713 // we don't have to worry that it will accidentally refer to the
1714 // newly declared variables. But we do have to worry about a mix of
1715 // newly declared variables and old variables if the old variables
1716 // appear in the initializations.
1718 Expression_list::const_iterator pexpr
;
1720 pexpr
= init
->begin();
1721 bool any_new
= false;
1722 Expression_list
* vars
= new Expression_list();
1723 Expression_list
* vals
= new Expression_list();
1724 for (Typed_identifier_list::const_iterator p
= til
->begin();
1729 go_assert(pexpr
!= init
->end());
1730 this->init_var(*p
, type
, init
== NULL
? NULL
: *pexpr
, is_coloneq
,
1731 false, &any_new
, vars
, vals
);
1736 go_assert(pexpr
== init
->end());
1737 if (is_coloneq
&& !any_new
)
1738 go_error_at(location
, "variables redeclared but no variable is new");
1739 this->finish_init_vars(vars
, vals
, location
);
1742 // See if we need to initialize a list of variables from a function
1743 // call. This returns true if we have set up the variables and the
1747 Parse::init_vars_from_call(const Typed_identifier_list
* vars
, Type
* type
,
1748 Expression
* expr
, bool is_coloneq
,
1751 Call_expression
* call
= expr
->call_expression();
1755 // This is a function call. We can't check here whether it returns
1756 // the right number of values, but it might. Declare the variables,
1757 // and then assign the results of the call to them.
1759 call
->set_expected_result_count(vars
->size());
1761 Named_object
* first_var
= NULL
;
1762 unsigned int index
= 0;
1763 bool any_new
= false;
1764 Expression_list
* ivars
= new Expression_list();
1765 Expression_list
* ivals
= new Expression_list();
1766 for (Typed_identifier_list::const_iterator pv
= vars
->begin();
1770 Expression
* init
= Expression::make_call_result(call
, index
);
1771 Named_object
* no
= this->init_var(*pv
, type
, init
, is_coloneq
, false,
1772 &any_new
, ivars
, ivals
);
1774 if (this->gogo_
->in_global_scope() && no
->is_variable())
1776 if (first_var
== NULL
)
1780 // If the current object is a redefinition of another object, we
1781 // might have already recorded the dependency relationship between
1782 // it and the first variable. Either way, an error will be
1783 // reported for the redefinition and we don't need to properly
1784 // record dependency information for an invalid program.
1785 if (no
->is_redefinition())
1788 // The subsequent vars have an implicit dependency on
1789 // the first one, so that everything gets initialized in
1790 // the right order and so that we detect cycles
1792 this->gogo_
->record_var_depends_on(no
->var_value(), first_var
);
1797 if (is_coloneq
&& !any_new
)
1798 go_error_at(location
, "variables redeclared but no variable is new");
1800 this->finish_init_vars(ivars
, ivals
, location
);
1805 // See if we need to initialize a pair of values from a map index
1806 // expression. This returns true if we have set up the variables and
1807 // the initialization.
1810 Parse::init_vars_from_map(const Typed_identifier_list
* vars
, Type
* type
,
1811 Expression
* expr
, bool is_coloneq
,
1814 Index_expression
* index
= expr
->index_expression();
1817 if (vars
->size() != 2)
1820 // This is an index which is being assigned to two variables. It
1821 // must be a map index. Declare the variables, and then assign the
1822 // results of the map index.
1823 bool any_new
= false;
1824 Typed_identifier_list::const_iterator p
= vars
->begin();
1825 Expression
* init
= type
== NULL
? index
: NULL
;
1826 Named_object
* val_no
= this->init_var(*p
, type
, init
, is_coloneq
,
1827 type
== NULL
, &any_new
, NULL
, NULL
);
1828 if (type
== NULL
&& any_new
&& val_no
->is_variable())
1829 val_no
->var_value()->set_type_from_init_tuple();
1830 Expression
* val_var
= Expression::make_var_reference(val_no
, location
);
1833 Type
* var_type
= type
;
1834 if (var_type
== NULL
)
1835 var_type
= Type::lookup_bool_type();
1836 Named_object
* no
= this->init_var(*p
, var_type
, NULL
, is_coloneq
, false,
1837 &any_new
, NULL
, NULL
);
1838 Expression
* present_var
= Expression::make_var_reference(no
, location
);
1840 if (is_coloneq
&& !any_new
)
1841 go_error_at(location
, "variables redeclared but no variable is new");
1843 Statement
* s
= Statement::make_tuple_map_assignment(val_var
, present_var
,
1846 if (!this->gogo_
->in_global_scope())
1847 this->gogo_
->add_statement(s
);
1848 else if (!val_no
->is_sink())
1850 if (val_no
->is_variable())
1851 val_no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1853 else if (!no
->is_sink())
1855 if (no
->is_variable())
1856 no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1860 // Execute the map index expression just so that we can fail if
1862 Named_object
* dummy
= this->create_dummy_global(Type::lookup_bool_type(),
1864 dummy
->var_value()->add_preinit_statement(this->gogo_
, s
);
1870 // See if we need to initialize a pair of values from a receive
1871 // expression. This returns true if we have set up the variables and
1872 // the initialization.
1875 Parse::init_vars_from_receive(const Typed_identifier_list
* vars
, Type
* type
,
1876 Expression
* expr
, bool is_coloneq
,
1879 Receive_expression
* receive
= expr
->receive_expression();
1880 if (receive
== NULL
)
1882 if (vars
->size() != 2)
1885 // This is a receive expression which is being assigned to two
1886 // variables. Declare the variables, and then assign the results of
1888 bool any_new
= false;
1889 Typed_identifier_list::const_iterator p
= vars
->begin();
1890 Expression
* init
= type
== NULL
? receive
: NULL
;
1891 Named_object
* val_no
= this->init_var(*p
, type
, init
, is_coloneq
,
1892 type
== NULL
, &any_new
, NULL
, NULL
);
1893 if (type
== NULL
&& any_new
&& val_no
->is_variable())
1894 val_no
->var_value()->set_type_from_init_tuple();
1895 Expression
* val_var
= Expression::make_var_reference(val_no
, location
);
1898 Type
* var_type
= type
;
1899 if (var_type
== NULL
)
1900 var_type
= Type::lookup_bool_type();
1901 Named_object
* no
= this->init_var(*p
, var_type
, NULL
, is_coloneq
, false,
1902 &any_new
, NULL
, NULL
);
1903 Expression
* received_var
= Expression::make_var_reference(no
, location
);
1905 if (is_coloneq
&& !any_new
)
1906 go_error_at(location
, "variables redeclared but no variable is new");
1908 Statement
* s
= Statement::make_tuple_receive_assignment(val_var
,
1913 if (!this->gogo_
->in_global_scope())
1914 this->gogo_
->add_statement(s
);
1915 else if (!val_no
->is_sink())
1917 if (val_no
->is_variable())
1918 val_no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1920 else if (!no
->is_sink())
1922 if (no
->is_variable())
1923 no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1927 Named_object
* dummy
= this->create_dummy_global(Type::lookup_bool_type(),
1929 dummy
->var_value()->add_preinit_statement(this->gogo_
, s
);
1935 // See if we need to initialize a pair of values from a type guard
1936 // expression. This returns true if we have set up the variables and
1937 // the initialization.
1940 Parse::init_vars_from_type_guard(const Typed_identifier_list
* vars
,
1941 Type
* type
, Expression
* expr
,
1942 bool is_coloneq
, Location location
)
1944 Type_guard_expression
* type_guard
= expr
->type_guard_expression();
1945 if (type_guard
== NULL
)
1947 if (vars
->size() != 2)
1950 // This is a type guard expression which is being assigned to two
1951 // variables. Declare the variables, and then assign the results of
1953 bool any_new
= false;
1954 Typed_identifier_list::const_iterator p
= vars
->begin();
1955 Type
* var_type
= type
;
1956 if (var_type
== NULL
)
1957 var_type
= type_guard
->type();
1958 Named_object
* val_no
= this->init_var(*p
, var_type
, NULL
, is_coloneq
, false,
1959 &any_new
, NULL
, NULL
);
1960 Expression
* val_var
= Expression::make_var_reference(val_no
, location
);
1964 if (var_type
== NULL
)
1965 var_type
= Type::lookup_bool_type();
1966 Named_object
* no
= this->init_var(*p
, var_type
, NULL
, is_coloneq
, false,
1967 &any_new
, NULL
, NULL
);
1968 Expression
* ok_var
= Expression::make_var_reference(no
, location
);
1970 Expression
* texpr
= type_guard
->expr();
1971 Type
* t
= type_guard
->type();
1972 Statement
* s
= Statement::make_tuple_type_guard_assignment(val_var
, ok_var
,
1976 if (is_coloneq
&& !any_new
)
1977 go_error_at(location
, "variables redeclared but no variable is new");
1979 if (!this->gogo_
->in_global_scope())
1980 this->gogo_
->add_statement(s
);
1981 else if (!val_no
->is_sink())
1983 if (val_no
->is_variable())
1984 val_no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1986 else if (!no
->is_sink())
1988 if (no
->is_variable())
1989 no
->var_value()->add_preinit_statement(this->gogo_
, s
);
1993 Named_object
* dummy
= this->create_dummy_global(type
, NULL
, location
);
1994 dummy
->var_value()->add_preinit_statement(this->gogo_
, s
);
2000 // Create a single variable. If IS_COLONEQ is true, we permit
2001 // redeclarations in the same block, and we set *IS_NEW when we find a
2002 // new variable which is not a redeclaration.
2005 Parse::init_var(const Typed_identifier
& tid
, Type
* type
, Expression
* init
,
2006 bool is_coloneq
, bool type_from_init
, bool* is_new
,
2007 Expression_list
* vars
, Expression_list
* vals
)
2009 Location location
= tid
.location();
2011 if (Gogo::is_sink_name(tid
.name()))
2013 if (!type_from_init
&& init
!= NULL
)
2015 if (this->gogo_
->in_global_scope())
2016 return this->create_dummy_global(type
, init
, location
);
2019 // Create a dummy variable so that we will check whether the
2020 // initializer can be assigned to the type.
2021 Variable
* var
= new Variable(type
, init
, false, false, false,
2026 snprintf(buf
, sizeof buf
, "sink$%d", count
);
2028 return this->gogo_
->add_variable(buf
, var
);
2032 this->gogo_
->add_type_to_verify(type
);
2033 return this->gogo_
->add_sink();
2038 Named_object
* no
= this->gogo_
->lookup_in_block(tid
.name());
2040 && (no
->is_variable() || no
->is_result_variable()))
2042 // INIT may be NULL even when IS_COLONEQ is true for cases
2043 // like v, ok := x.(int).
2044 if (!type_from_init
&& init
!= NULL
)
2046 go_assert(vars
!= NULL
&& vals
!= NULL
);
2047 vars
->push_back(Expression::make_var_reference(no
, location
));
2048 vals
->push_back(init
);
2054 Variable
* var
= new Variable(type
, init
, this->gogo_
->in_global_scope(),
2055 false, false, location
);
2056 Named_object
* no
= this->gogo_
->add_variable(tid
.name(), var
);
2057 if (!no
->is_variable())
2059 // The name is already defined, so we just gave an error.
2060 return this->gogo_
->add_sink();
2065 // Create a dummy global variable to force an initializer to be run in
2066 // the right place. This is used when a sink variable is initialized
2070 Parse::create_dummy_global(Type
* type
, Expression
* init
,
2073 if (type
== NULL
&& init
== NULL
)
2074 type
= Type::lookup_bool_type();
2075 Variable
* var
= new Variable(type
, init
, true, false, false, location
);
2078 snprintf(buf
, sizeof buf
, "_.%d", count
);
2080 return this->gogo_
->add_variable(buf
, var
);
2083 // Finish the variable initialization by executing any assignments to
2084 // existing variables when using :=. These must be done as a tuple
2085 // assignment in case of something like n, a, b := 1, b, a.
2088 Parse::finish_init_vars(Expression_list
* vars
, Expression_list
* vals
,
2096 else if (vars
->size() == 1)
2098 go_assert(!this->gogo_
->in_global_scope());
2099 this->gogo_
->add_statement(Statement::make_assignment(vars
->front(),
2107 go_assert(!this->gogo_
->in_global_scope());
2108 this->gogo_
->add_statement(Statement::make_tuple_assignment(vars
, vals
,
2113 // SimpleVarDecl = identifier ":=" Expression .
2115 // We've already seen the identifier.
2117 // FIXME: We also have to implement
2118 // IdentifierList ":=" ExpressionList
2119 // In order to support both "a, b := 1, 0" and "a, b = 1, 0" we accept
2120 // tuple assignments here as well.
2122 // If MAY_BE_COMPOSITE_LIT is true, the expression on the right hand
2123 // side may be a composite literal.
2125 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
2128 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
2129 // guard (var := expr.("type") using the literal keyword "type").
2132 Parse::simple_var_decl_or_assignment(const std::string
& name
,
2134 bool may_be_composite_lit
,
2135 Range_clause
* p_range_clause
,
2136 Type_switch
* p_type_switch
)
2138 Typed_identifier_list til
;
2139 til
.push_back(Typed_identifier(name
, NULL
, location
));
2141 std::set
<std::string
> uniq_idents
;
2142 uniq_idents
.insert(name
);
2143 std::string dup_name
;
2146 // We've seen one identifier. If we see a comma now, this could be
2148 if (this->peek_token()->is_op(OPERATOR_COMMA
))
2150 go_assert(p_type_switch
== NULL
);
2153 const Token
* token
= this->advance_token();
2154 if (!token
->is_identifier())
2157 std::string id
= token
->identifier();
2158 bool is_id_exported
= token
->is_identifier_exported();
2159 Location id_location
= token
->location();
2160 std::pair
<std::set
<std::string
>::iterator
, bool> ins
;
2162 token
= this->advance_token();
2163 if (!token
->is_op(OPERATOR_COMMA
))
2165 if (token
->is_op(OPERATOR_COLONEQ
))
2167 id
= this->gogo_
->pack_hidden_name(id
, is_id_exported
);
2168 ins
= uniq_idents
.insert(id
);
2169 if (!ins
.second
&& !Gogo::is_sink_name(id
))
2170 go_error_at(id_location
, "multiple assignments to %s",
2171 Gogo::message_name(id
).c_str());
2172 til
.push_back(Typed_identifier(id
, NULL
, location
));
2175 this->unget_token(Token::make_identifier_token(id
,
2181 id
= this->gogo_
->pack_hidden_name(id
, is_id_exported
);
2182 ins
= uniq_idents
.insert(id
);
2183 if (!ins
.second
&& !Gogo::is_sink_name(id
))
2185 dup_name
= Gogo::message_name(id
);
2186 dup_loc
= id_location
;
2188 til
.push_back(Typed_identifier(id
, NULL
, location
));
2191 // We have a comma separated list of identifiers in TIL. If the
2192 // next token is COLONEQ, then this is a simple var decl, and we
2193 // have the complete list of identifiers. If the next token is
2194 // not COLONEQ, then the only valid parse is a tuple assignment.
2195 // The list of identifiers we have so far is really a list of
2196 // expressions. There are more expressions following.
2198 if (!this->peek_token()->is_op(OPERATOR_COLONEQ
))
2200 Expression_list
* exprs
= new Expression_list
;
2201 for (Typed_identifier_list::const_iterator p
= til
.begin();
2204 exprs
->push_back(this->id_to_expression(p
->name(), p
->location(),
2207 Expression_list
* more_exprs
=
2208 this->expression_list(NULL
, true, may_be_composite_lit
);
2209 for (Expression_list::const_iterator p
= more_exprs
->begin();
2210 p
!= more_exprs
->end();
2212 exprs
->push_back(*p
);
2215 this->tuple_assignment(exprs
, may_be_composite_lit
, p_range_clause
);
2220 go_assert(this->peek_token()->is_op(OPERATOR_COLONEQ
));
2221 const Token
* token
= this->advance_token();
2223 if (!dup_name
.empty())
2224 go_error_at(dup_loc
, "multiple assignments to %s", dup_name
.c_str());
2226 if (p_range_clause
!= NULL
&& token
->is_keyword(KEYWORD_RANGE
))
2228 this->range_clause_decl(&til
, p_range_clause
);
2232 Expression_list
* init
;
2233 if (p_type_switch
== NULL
)
2234 init
= this->expression_list(NULL
, false, may_be_composite_lit
);
2237 bool is_type_switch
= false;
2238 Expression
* expr
= this->expression(PRECEDENCE_NORMAL
, false,
2239 may_be_composite_lit
,
2240 &is_type_switch
, NULL
);
2243 p_type_switch
->found
= true;
2244 p_type_switch
->name
= name
;
2245 p_type_switch
->location
= location
;
2246 p_type_switch
->expr
= expr
;
2250 if (!this->peek_token()->is_op(OPERATOR_COMMA
))
2252 init
= new Expression_list();
2253 init
->push_back(expr
);
2257 this->advance_token();
2258 init
= this->expression_list(expr
, false, may_be_composite_lit
);
2262 this->init_vars(&til
, NULL
, init
, true, location
);
2265 // FunctionDecl = "func" identifier Signature [ Block ] .
2266 // MethodDecl = "func" Receiver identifier Signature [ Block ] .
2268 // Deprecated gcc extension:
2269 // FunctionDecl = "func" identifier Signature
2270 // __asm__ "(" string_lit ")" .
2271 // This extension means a function whose real name is the identifier
2272 // inside the asm. This extension will be removed at some future
2273 // date. It has been replaced with //extern or //go:linkname comments.
2275 // PRAGMAS is a bitset of magic comments.
2278 Parse::function_decl(unsigned int pragmas
)
2280 go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC
));
2281 Location location
= this->location();
2282 std::string extern_name
= this->lex_
->extern_name();
2283 const Token
* token
= this->advance_token();
2285 bool expected_receiver
= false;
2286 Typed_identifier
* rec
= NULL
;
2287 if (token
->is_op(OPERATOR_LPAREN
))
2289 expected_receiver
= true;
2290 rec
= this->receiver();
2291 token
= this->peek_token();
2294 if (!token
->is_identifier())
2296 go_error_at(this->location(), "expected function name");
2301 this->gogo_
->pack_hidden_name(token
->identifier(),
2302 token
->is_identifier_exported());
2304 this->advance_token();
2306 Function_type
* fntype
= this->signature(rec
, this->location());
2308 Named_object
* named_object
= NULL
;
2310 if (this->peek_token()->is_keyword(KEYWORD_ASM
))
2312 if (!this->advance_token()->is_op(OPERATOR_LPAREN
))
2314 go_error_at(this->location(), "expected %<(%>");
2317 token
= this->advance_token();
2318 if (!token
->is_string())
2320 go_error_at(this->location(), "expected string");
2323 std::string asm_name
= token
->string_value();
2324 if (!this->advance_token()->is_op(OPERATOR_RPAREN
))
2326 go_error_at(this->location(), "expected %<)%>");
2329 this->advance_token();
2330 if (!Gogo::is_sink_name(name
))
2332 named_object
= this->gogo_
->declare_function(name
, fntype
, location
);
2333 if (named_object
->is_function_declaration())
2334 named_object
->func_declaration_value()->set_asm_name(asm_name
);
2338 // Check for the easy error of a newline before the opening brace.
2339 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
2341 Location semi_loc
= this->location();
2342 if (this->advance_token()->is_op(OPERATOR_LCURLY
))
2343 go_error_at(this->location(),
2344 "unexpected semicolon or newline before %<{%>");
2346 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON
,
2358 { GOPRAGMA_NOINTERFACE
, "nointerface", false, false, true },
2359 { GOPRAGMA_NOESCAPE
, "noescape", true, false, false },
2360 { GOPRAGMA_NORACE
, "norace", false, true, true },
2361 { GOPRAGMA_NOSPLIT
, "nosplit", false, true, true },
2362 { GOPRAGMA_NOINLINE
, "noinline", false, true, true },
2363 { GOPRAGMA_SYSTEMSTACK
, "systemstack", false, true, true },
2364 { GOPRAGMA_NOWRITEBARRIER
, "nowritebarrier", false, true, true },
2365 { GOPRAGMA_NOWRITEBARRIERREC
, "nowritebarrierrec", false, true, true },
2366 { GOPRAGMA_CGOUNSAFEARGS
, "cgo_unsafe_args", false, true, true },
2367 { GOPRAGMA_UINTPTRESCAPES
, "uintptrescapes", true, true, true },
2370 bool is_decl
= !this->peek_token()->is_op(OPERATOR_LCURLY
);
2374 i
< sizeof(pragma_check
) / sizeof(pragma_check
[0]);
2377 if ((pragmas
& pragma_check
[i
].bit
) == 0)
2382 if (pragma_check
[i
].decl_ok
)
2384 go_warning_at(location
, 0,
2385 ("ignoring magic //go:%s comment "
2386 "before declaration"),
2387 pragma_check
[i
].name
);
2389 else if (rec
== NULL
)
2391 if (pragma_check
[i
].func_ok
)
2393 go_warning_at(location
, 0,
2394 ("ignoring magic //go:%s comment "
2395 "before function definition"),
2396 pragma_check
[i
].name
);
2400 if (pragma_check
[i
].method_ok
)
2402 go_warning_at(location
, 0,
2403 ("ignoring magic //go:%s comment "
2404 "before method definition"),
2405 pragma_check
[i
].name
);
2408 pragmas
&= ~ pragma_check
[i
].bit
;
2414 if (named_object
== NULL
)
2416 // Function declarations with the blank identifier as a name are
2417 // mostly ignored since they cannot be called. We make an object
2418 // for this declaration for type-checking purposes.
2419 if (Gogo::is_sink_name(name
))
2423 snprintf(buf
, sizeof buf
, ".$sinkfndecl%d", count
);
2425 name
= std::string(buf
);
2429 || (expected_receiver
&& rec
== NULL
))
2430 this->gogo_
->add_erroneous_name(name
);
2433 named_object
= this->gogo_
->declare_function(name
, fntype
,
2435 if (!extern_name
.empty()
2436 && named_object
->is_function_declaration())
2438 Function_declaration
* fd
=
2439 named_object
->func_declaration_value();
2440 fd
->set_asm_name(extern_name
);
2445 if (pragmas
!= 0 && named_object
->is_function_declaration())
2446 named_object
->func_declaration_value()->set_pragmas(pragmas
);
2450 bool hold_is_erroneous_function
= this->is_erroneous_function_
;
2453 fntype
= Type::make_function_type(NULL
, NULL
, NULL
, location
);
2454 this->is_erroneous_function_
= true;
2455 if (!Gogo::is_sink_name(name
))
2456 this->gogo_
->add_erroneous_name(name
);
2457 name
= this->gogo_
->pack_hidden_name("_", false);
2459 named_object
= this->gogo_
->start_function(name
, fntype
, true, location
);
2460 Location end_loc
= this->block();
2461 this->gogo_
->finish_function(end_loc
);
2464 && !this->is_erroneous_function_
2465 && named_object
->is_function())
2466 named_object
->func_value()->set_pragmas(pragmas
);
2467 this->is_erroneous_function_
= hold_is_erroneous_function
;
2471 // Receiver = Parameters .
2476 Location location
= this->location();
2477 Typed_identifier_list
* til
;
2478 if (!this->parameters(&til
, NULL
))
2480 else if (til
== NULL
|| til
->empty())
2482 go_error_at(location
, "method has no receiver");
2485 else if (til
->size() > 1)
2487 go_error_at(location
, "method has multiple receivers");
2491 return &til
->front();
2494 // Operand = Literal | QualifiedIdent | MethodExpr | "(" Expression ")" .
2495 // Literal = BasicLit | CompositeLit | FunctionLit .
2496 // BasicLit = int_lit | float_lit | imaginary_lit | char_lit | string_lit .
2498 // If MAY_BE_SINK is true, this operand may be "_".
2500 // If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
2501 // if the entire expression is in parentheses.
2504 Parse::operand(bool may_be_sink
, bool* is_parenthesized
)
2506 const Token
* token
= this->peek_token();
2508 switch (token
->classification())
2510 case Token::TOKEN_IDENTIFIER
:
2512 Location location
= token
->location();
2513 std::string id
= token
->identifier();
2514 bool is_exported
= token
->is_identifier_exported();
2515 std::string packed
= this->gogo_
->pack_hidden_name(id
, is_exported
);
2517 Named_object
* in_function
;
2518 Named_object
* named_object
= this->gogo_
->lookup(packed
, &in_function
);
2520 Package
* package
= NULL
;
2521 if (named_object
!= NULL
&& named_object
->is_package())
2523 if (!this->advance_token()->is_op(OPERATOR_DOT
)
2524 || !this->advance_token()->is_identifier())
2526 go_error_at(location
, "unexpected reference to package");
2527 return Expression::make_error(location
);
2529 package
= named_object
->package_value();
2530 package
->note_usage(id
);
2531 id
= this->peek_token()->identifier();
2532 is_exported
= this->peek_token()->is_identifier_exported();
2533 packed
= this->gogo_
->pack_hidden_name(id
, is_exported
);
2534 named_object
= package
->lookup(packed
);
2535 location
= this->location();
2536 go_assert(in_function
== NULL
);
2539 this->advance_token();
2541 if (named_object
!= NULL
2542 && named_object
->is_type()
2543 && !named_object
->type_value()->is_visible())
2545 go_assert(package
!= NULL
);
2546 go_error_at(location
, "invalid reference to hidden type %<%s.%s%>",
2547 Gogo::message_name(package
->package_name()).c_str(),
2548 Gogo::message_name(id
).c_str());
2549 return Expression::make_error(location
);
2553 if (named_object
== NULL
)
2555 if (package
!= NULL
)
2557 std::string n1
= Gogo::message_name(package
->package_name());
2558 std::string n2
= Gogo::message_name(id
);
2560 go_error_at(location
,
2561 ("invalid reference to unexported identifier "
2563 n1
.c_str(), n2
.c_str());
2565 go_error_at(location
,
2566 "reference to undefined identifier %<%s.%s%>",
2567 n1
.c_str(), n2
.c_str());
2568 return Expression::make_error(location
);
2571 named_object
= this->gogo_
->add_unknown_name(packed
, location
);
2574 if (in_function
!= NULL
2575 && in_function
!= this->gogo_
->current_function()
2576 && (named_object
->is_variable()
2577 || named_object
->is_result_variable()))
2578 return this->enclosing_var_reference(in_function
, named_object
,
2579 may_be_sink
, location
);
2581 switch (named_object
->classification())
2583 case Named_object::NAMED_OBJECT_CONST
:
2584 return Expression::make_const_reference(named_object
, location
);
2585 case Named_object::NAMED_OBJECT_TYPE
:
2586 return Expression::make_type(named_object
->type_value(), location
);
2587 case Named_object::NAMED_OBJECT_TYPE_DECLARATION
:
2589 Type
* t
= Type::make_forward_declaration(named_object
);
2590 return Expression::make_type(t
, location
);
2592 case Named_object::NAMED_OBJECT_VAR
:
2593 case Named_object::NAMED_OBJECT_RESULT_VAR
:
2594 // Any left-hand-side can be a sink, so if this can not be
2595 // a sink, then it must be a use of the variable.
2597 this->mark_var_used(named_object
);
2598 return Expression::make_var_reference(named_object
, location
);
2599 case Named_object::NAMED_OBJECT_SINK
:
2601 return Expression::make_sink(location
);
2604 go_error_at(location
, "cannot use _ as value");
2605 return Expression::make_error(location
);
2607 case Named_object::NAMED_OBJECT_FUNC
:
2608 case Named_object::NAMED_OBJECT_FUNC_DECLARATION
:
2609 return Expression::make_func_reference(named_object
, NULL
,
2611 case Named_object::NAMED_OBJECT_UNKNOWN
:
2613 Unknown_expression
* ue
=
2614 Expression::make_unknown_reference(named_object
, location
);
2615 if (this->is_erroneous_function_
)
2616 ue
->set_no_error_message();
2619 case Named_object::NAMED_OBJECT_ERRONEOUS
:
2620 return Expression::make_error(location
);
2627 case Token::TOKEN_STRING
:
2628 ret
= Expression::make_string(token
->string_value(), token
->location());
2629 this->advance_token();
2632 case Token::TOKEN_CHARACTER
:
2633 ret
= Expression::make_character(token
->character_value(), NULL
,
2635 this->advance_token();
2638 case Token::TOKEN_INTEGER
:
2639 ret
= Expression::make_integer_z(token
->integer_value(), NULL
,
2641 this->advance_token();
2644 case Token::TOKEN_FLOAT
:
2645 ret
= Expression::make_float(token
->float_value(), NULL
,
2647 this->advance_token();
2650 case Token::TOKEN_IMAGINARY
:
2653 mpfr_init_set_ui(zero
, 0, GMP_RNDN
);
2655 mpc_init2(val
, mpc_precision
);
2656 mpc_set_fr_fr(val
, zero
, *token
->imaginary_value(), MPC_RNDNN
);
2658 ret
= Expression::make_complex(&val
, NULL
, token
->location());
2660 this->advance_token();
2664 case Token::TOKEN_KEYWORD
:
2665 switch (token
->keyword())
2668 return this->function_lit();
2670 case KEYWORD_INTERFACE
:
2672 case KEYWORD_STRUCT
:
2674 Location location
= token
->location();
2675 return Expression::make_type(this->type(), location
);
2682 case Token::TOKEN_OPERATOR
:
2683 if (token
->is_op(OPERATOR_LPAREN
))
2685 this->advance_token();
2686 ret
= this->expression(PRECEDENCE_NORMAL
, may_be_sink
, true, NULL
,
2688 if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
2689 go_error_at(this->location(), "missing %<)%>");
2691 this->advance_token();
2692 if (is_parenthesized
!= NULL
)
2693 *is_parenthesized
= true;
2696 else if (token
->is_op(OPERATOR_LSQUARE
))
2698 // Here we call array_type directly, as this is the only
2699 // case where an ellipsis is permitted for an array type.
2700 Location location
= token
->location();
2701 return Expression::make_type(this->array_type(true), location
);
2709 go_error_at(this->location(), "expected operand");
2710 return Expression::make_error(this->location());
2713 // Handle a reference to a variable in an enclosing function. We add
2714 // it to a list of such variables. We return a reference to a field
2715 // in a struct which will be passed on the static chain when calling
2716 // the current function.
2719 Parse::enclosing_var_reference(Named_object
* in_function
, Named_object
* var
,
2720 bool may_be_sink
, Location location
)
2722 go_assert(var
->is_variable() || var
->is_result_variable());
2724 // Any left-hand-side can be a sink, so if this can not be
2725 // a sink, then it must be a use of the variable.
2727 this->mark_var_used(var
);
2729 Named_object
* this_function
= this->gogo_
->current_function();
2730 Named_object
* closure
= this_function
->func_value()->closure_var();
2732 // The last argument to the Enclosing_var constructor is the index
2733 // of this variable in the closure. We add 1 to the current number
2734 // of enclosed variables, because the first field in the closure
2735 // points to the function code.
2736 Enclosing_var
ev(var
, in_function
, this->enclosing_vars_
.size() + 1);
2737 std::pair
<Enclosing_vars::iterator
, bool> ins
=
2738 this->enclosing_vars_
.insert(ev
);
2741 // This is a variable we have not seen before. Add a new field
2742 // to the closure type.
2743 this_function
->func_value()->add_closure_field(var
, location
);
2746 Expression
* closure_ref
= Expression::make_var_reference(closure
,
2749 Expression::make_dereference(closure_ref
,
2750 Expression::NIL_CHECK_NOT_NEEDED
,
2753 // The closure structure holds pointers to the variables, so we need
2754 // to introduce an indirection.
2755 Expression
* e
= Expression::make_field_reference(closure_ref
,
2758 e
= Expression::make_dereference(e
, Expression::NIL_CHECK_NOT_NEEDED
,
2760 return Expression::make_enclosing_var_reference(e
, var
, location
);
2763 // CompositeLit = LiteralType LiteralValue .
2764 // LiteralType = StructType | ArrayType | "[" "..." "]" ElementType |
2765 // SliceType | MapType | TypeName .
2766 // LiteralValue = "{" [ ElementList [ "," ] ] "}" .
2767 // ElementList = Element { "," Element } .
2768 // Element = [ Key ":" ] Value .
2769 // Key = FieldName | ElementIndex .
2770 // FieldName = identifier .
2771 // ElementIndex = Expression .
2772 // Value = Expression | LiteralValue .
2774 // We have already seen the type if there is one, and we are now
2775 // looking at the LiteralValue. The case "[" "..." "]" ElementType
2776 // will be seen here as an array type whose length is "nil". The
2777 // DEPTH parameter is non-zero if this is an embedded composite
2778 // literal and the type was omitted. It gives the number of steps up
2779 // to the type which was provided. E.g., in [][]int{{1}} it will be
2780 // 1. In [][][]int{{{1}}} it will be 2.
2783 Parse::composite_lit(Type
* type
, int depth
, Location location
)
2785 go_assert(this->peek_token()->is_op(OPERATOR_LCURLY
));
2786 this->advance_token();
2788 if (this->peek_token()->is_op(OPERATOR_RCURLY
))
2790 this->advance_token();
2791 return Expression::make_composite_literal(type
, depth
, false, NULL
,
2795 bool has_keys
= false;
2796 bool all_are_names
= true;
2797 Expression_list
* vals
= new Expression_list
;
2801 bool is_type_omitted
= false;
2802 bool is_name
= false;
2804 const Token
* token
= this->peek_token();
2806 if (token
->is_identifier())
2808 std::string identifier
= token
->identifier();
2809 bool is_exported
= token
->is_identifier_exported();
2810 Location location
= token
->location();
2812 if (this->advance_token()->is_op(OPERATOR_COLON
))
2814 // This may be a field name. We don't know for sure--it
2815 // could also be an expression for an array index. We
2816 // don't want to parse it as an expression because may
2817 // trigger various errors, e.g., if this identifier
2818 // happens to be the name of a package.
2819 Gogo
* gogo
= this->gogo_
;
2820 val
= this->id_to_expression(gogo
->pack_hidden_name(identifier
,
2827 this->unget_token(Token::make_identifier_token(identifier
,
2830 val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
,
2834 else if (!token
->is_op(OPERATOR_LCURLY
))
2835 val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
2838 // This must be a composite literal inside another composite
2839 // literal, with the type omitted for the inner one.
2840 val
= this->composite_lit(type
, depth
+ 1, token
->location());
2841 is_type_omitted
= true;
2844 token
= this->peek_token();
2845 if (!token
->is_op(OPERATOR_COLON
))
2848 vals
->push_back(NULL
);
2853 if (is_type_omitted
)
2855 // VAL is a nested composite literal with an omitted type being
2856 // used a key. Record this information in VAL so that the correct
2857 // type is associated with the literal value if VAL is a
2859 val
->complit()->update_key_path(depth
);
2862 this->advance_token();
2864 if (!has_keys
&& !vals
->empty())
2866 Expression_list
* newvals
= new Expression_list
;
2867 for (Expression_list::const_iterator p
= vals
->begin();
2871 newvals
->push_back(NULL
);
2872 newvals
->push_back(*p
);
2879 if (val
->unknown_expression() != NULL
)
2880 val
->unknown_expression()->set_is_composite_literal_key();
2882 vals
->push_back(val
);
2884 if (!token
->is_op(OPERATOR_LCURLY
))
2885 val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
2888 // This must be a composite literal inside another
2889 // composite literal, with the type omitted for the
2891 val
= this->composite_lit(type
, depth
+ 1, token
->location());
2894 token
= this->peek_token();
2897 vals
->push_back(val
);
2900 all_are_names
= false;
2902 if (token
->is_op(OPERATOR_COMMA
))
2904 if (this->advance_token()->is_op(OPERATOR_RCURLY
))
2906 this->advance_token();
2910 else if (token
->is_op(OPERATOR_RCURLY
))
2912 this->advance_token();
2917 if (token
->is_op(OPERATOR_SEMICOLON
))
2918 go_error_at(this->location(),
2919 ("need trailing comma before newline "
2920 "in composite literal"));
2922 go_error_at(this->location(), "expected %<,%> or %<}%>");
2924 this->gogo_
->mark_locals_used();
2926 while (!token
->is_eof()
2927 && (depth
> 0 || !token
->is_op(OPERATOR_RCURLY
)))
2929 if (token
->is_op(OPERATOR_LCURLY
))
2931 else if (token
->is_op(OPERATOR_RCURLY
))
2933 token
= this->advance_token();
2935 if (token
->is_op(OPERATOR_RCURLY
))
2936 this->advance_token();
2938 return Expression::make_error(location
);
2942 return Expression::make_composite_literal(type
, depth
, has_keys
, vals
,
2943 all_are_names
, location
);
2946 // FunctionLit = "func" Signature Block .
2949 Parse::function_lit()
2951 Location location
= this->location();
2952 go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC
));
2953 this->advance_token();
2955 Enclosing_vars hold_enclosing_vars
;
2956 hold_enclosing_vars
.swap(this->enclosing_vars_
);
2958 Function_type
* type
= this->signature(NULL
, location
);
2959 bool fntype_is_error
= false;
2962 type
= Type::make_function_type(NULL
, NULL
, NULL
, location
);
2963 fntype_is_error
= true;
2966 // For a function literal, the next token must be a '{'. If we
2967 // don't see that, then we may have a type expression.
2968 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
2970 hold_enclosing_vars
.swap(this->enclosing_vars_
);
2971 return Expression::make_type(type
, location
);
2974 bool hold_is_erroneous_function
= this->is_erroneous_function_
;
2975 if (fntype_is_error
)
2976 this->is_erroneous_function_
= true;
2978 Bc_stack
* hold_break_stack
= this->break_stack_
;
2979 Bc_stack
* hold_continue_stack
= this->continue_stack_
;
2980 this->break_stack_
= NULL
;
2981 this->continue_stack_
= NULL
;
2983 Named_object
* no
= this->gogo_
->start_function("", type
, true, location
);
2985 Location end_loc
= this->block();
2987 this->gogo_
->finish_function(end_loc
);
2989 if (this->break_stack_
!= NULL
)
2990 delete this->break_stack_
;
2991 if (this->continue_stack_
!= NULL
)
2992 delete this->continue_stack_
;
2993 this->break_stack_
= hold_break_stack
;
2994 this->continue_stack_
= hold_continue_stack
;
2996 this->is_erroneous_function_
= hold_is_erroneous_function
;
2998 hold_enclosing_vars
.swap(this->enclosing_vars_
);
3000 Expression
* closure
= this->create_closure(no
, &hold_enclosing_vars
,
3003 return Expression::make_func_reference(no
, closure
, location
);
3006 // Create a closure for the nested function FUNCTION. This is based
3007 // on ENCLOSING_VARS, which is a list of all variables defined in
3008 // enclosing functions and referenced from FUNCTION. A closure is the
3009 // address of a struct which point to the real function code and
3010 // contains the addresses of all the referenced variables. This
3011 // returns NULL if no closure is required.
3014 Parse::create_closure(Named_object
* function
, Enclosing_vars
* enclosing_vars
,
3017 if (enclosing_vars
->empty())
3020 // Get the variables in order by their field index.
3022 size_t enclosing_var_count
= enclosing_vars
->size();
3023 std::vector
<Enclosing_var
> ev(enclosing_var_count
);
3024 for (Enclosing_vars::const_iterator p
= enclosing_vars
->begin();
3025 p
!= enclosing_vars
->end();
3028 // Subtract 1 because index 0 is the function code.
3029 ev
[p
->index() - 1] = *p
;
3032 // Build an initializer for a composite literal of the closure's
3035 Named_object
* enclosing_function
= this->gogo_
->current_function();
3036 Expression_list
* initializer
= new Expression_list
;
3038 initializer
->push_back(Expression::make_func_code_reference(function
,
3041 for (size_t i
= 0; i
< enclosing_var_count
; ++i
)
3043 // Add 1 to i because the first field in the closure is a
3044 // pointer to the function code.
3045 go_assert(ev
[i
].index() == i
+ 1);
3046 Named_object
* var
= ev
[i
].var();
3048 if (ev
[i
].in_function() == enclosing_function
)
3049 ref
= Expression::make_var_reference(var
, location
);
3051 ref
= this->enclosing_var_reference(ev
[i
].in_function(), var
,
3053 Expression
* refaddr
= Expression::make_unary(OPERATOR_AND
, ref
,
3055 initializer
->push_back(refaddr
);
3058 Named_object
* closure_var
= function
->func_value()->closure_var();
3059 Struct_type
* st
= closure_var
->var_value()->type()->deref()->struct_type();
3060 Expression
* cv
= Expression::make_struct_composite_literal(st
, initializer
,
3062 return Expression::make_heap_expression(cv
, location
);
3065 // PrimaryExpr = Operand { Selector | Index | Slice | TypeGuard | Call } .
3067 // If MAY_BE_SINK is true, this expression may be "_".
3069 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3072 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3073 // guard (var := expr.("type") using the literal keyword "type").
3075 // If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
3076 // if the entire expression is in parentheses.
3079 Parse::primary_expr(bool may_be_sink
, bool may_be_composite_lit
,
3080 bool* is_type_switch
, bool* is_parenthesized
)
3082 Location start_loc
= this->location();
3083 bool operand_is_parenthesized
= false;
3084 bool whole_is_parenthesized
= false;
3086 Expression
* ret
= this->operand(may_be_sink
, &operand_is_parenthesized
);
3088 whole_is_parenthesized
= operand_is_parenthesized
;
3090 // An unknown name followed by a curly brace must be a composite
3091 // literal, and the unknown name must be a type.
3092 if (may_be_composite_lit
3093 && !operand_is_parenthesized
3094 && ret
->unknown_expression() != NULL
3095 && this->peek_token()->is_op(OPERATOR_LCURLY
))
3097 Named_object
* no
= ret
->unknown_expression()->named_object();
3098 Type
* type
= Type::make_forward_declaration(no
);
3099 ret
= Expression::make_type(type
, ret
->location());
3102 // We handle composite literals and type casts here, as it is the
3103 // easiest way to handle types which are in parentheses, as in
3105 if (ret
->is_type_expression())
3107 if (this->peek_token()->is_op(OPERATOR_LCURLY
))
3109 whole_is_parenthesized
= false;
3110 if (!may_be_composite_lit
)
3112 Type
* t
= ret
->type();
3113 if (t
->named_type() != NULL
3114 || t
->forward_declaration_type() != NULL
)
3115 go_error_at(start_loc
,
3116 _("parentheses required around this composite "
3117 "literal to avoid parsing ambiguity"));
3119 else if (operand_is_parenthesized
)
3120 go_error_at(start_loc
,
3121 "cannot parenthesize type in composite literal");
3122 ret
= this->composite_lit(ret
->type(), 0, ret
->location());
3124 else if (this->peek_token()->is_op(OPERATOR_LPAREN
))
3126 whole_is_parenthesized
= false;
3127 Location loc
= this->location();
3128 this->advance_token();
3129 Expression
* expr
= this->expression(PRECEDENCE_NORMAL
, false, true,
3131 if (this->peek_token()->is_op(OPERATOR_COMMA
))
3132 this->advance_token();
3133 if (this->peek_token()->is_op(OPERATOR_ELLIPSIS
))
3135 go_error_at(this->location(),
3136 "invalid use of %<...%> in type conversion");
3137 this->advance_token();
3139 if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
3140 go_error_at(this->location(), "expected %<)%>");
3142 this->advance_token();
3143 if (expr
->is_error_expression())
3147 Type
* t
= ret
->type();
3148 if (t
->classification() == Type::TYPE_ARRAY
3149 && t
->array_type()->length() != NULL
3150 && t
->array_type()->length()->is_nil_expression())
3152 go_error_at(ret
->location(),
3153 "use of %<[...]%> outside of array literal");
3154 ret
= Expression::make_error(loc
);
3157 ret
= Expression::make_cast(t
, expr
, loc
);
3164 const Token
* token
= this->peek_token();
3165 if (token
->is_op(OPERATOR_LPAREN
))
3167 whole_is_parenthesized
= false;
3168 ret
= this->call(this->verify_not_sink(ret
));
3170 else if (token
->is_op(OPERATOR_DOT
))
3172 whole_is_parenthesized
= false;
3173 ret
= this->selector(this->verify_not_sink(ret
), is_type_switch
);
3174 if (is_type_switch
!= NULL
&& *is_type_switch
)
3177 else if (token
->is_op(OPERATOR_LSQUARE
))
3179 whole_is_parenthesized
= false;
3180 ret
= this->index(this->verify_not_sink(ret
));
3186 if (whole_is_parenthesized
&& is_parenthesized
!= NULL
)
3187 *is_parenthesized
= true;
3192 // Selector = "." identifier .
3193 // TypeGuard = "." "(" QualifiedIdent ")" .
3195 // Note that Operand can expand to QualifiedIdent, which contains a
3196 // ".". That is handled directly in operand when it sees a package
3199 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3200 // guard (var := expr.("type") using the literal keyword "type").
3203 Parse::selector(Expression
* left
, bool* is_type_switch
)
3205 go_assert(this->peek_token()->is_op(OPERATOR_DOT
));
3206 Location location
= this->location();
3208 const Token
* token
= this->advance_token();
3209 if (token
->is_identifier())
3211 // This could be a field in a struct, or a method in an
3212 // interface, or a method associated with a type. We can't know
3213 // which until we have seen all the types.
3215 this->gogo_
->pack_hidden_name(token
->identifier(),
3216 token
->is_identifier_exported());
3217 if (token
->identifier() == "_")
3219 go_error_at(this->location(), "invalid use of %<_%>");
3220 name
= Gogo::erroneous_name();
3222 this->advance_token();
3223 return Expression::make_selector(left
, name
, location
);
3225 else if (token
->is_op(OPERATOR_LPAREN
))
3227 this->advance_token();
3229 if (!this->peek_token()->is_keyword(KEYWORD_TYPE
))
3230 type
= this->type();
3233 if (is_type_switch
!= NULL
)
3234 *is_type_switch
= true;
3237 go_error_at(this->location(),
3238 "use of %<.(type)%> outside type switch");
3239 type
= Type::make_error_type();
3241 this->advance_token();
3243 if (!this->peek_token()->is_op(OPERATOR_RPAREN
))
3244 go_error_at(this->location(), "missing %<)%>");
3246 this->advance_token();
3247 if (is_type_switch
!= NULL
&& *is_type_switch
)
3249 return Expression::make_type_guard(left
, type
, location
);
3253 go_error_at(this->location(), "expected identifier or %<(%>");
3258 // Index = "[" Expression "]" .
3259 // Slice = "[" Expression ":" [ Expression ] [ ":" Expression ] "]" .
3262 Parse::index(Expression
* expr
)
3264 Location location
= this->location();
3265 go_assert(this->peek_token()->is_op(OPERATOR_LSQUARE
));
3266 this->advance_token();
3269 if (!this->peek_token()->is_op(OPERATOR_COLON
))
3270 start
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
3272 start
= Expression::make_integer_ul(0, NULL
, location
);
3274 Expression
* end
= NULL
;
3275 if (this->peek_token()->is_op(OPERATOR_COLON
))
3277 // We use nil to indicate a missing high expression.
3278 if (this->advance_token()->is_op(OPERATOR_RSQUARE
))
3279 end
= Expression::make_nil(this->location());
3280 else if (this->peek_token()->is_op(OPERATOR_COLON
))
3282 go_error_at(this->location(),
3283 "middle index required in 3-index slice");
3284 end
= Expression::make_error(this->location());
3287 end
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
3290 Expression
* cap
= NULL
;
3291 if (this->peek_token()->is_op(OPERATOR_COLON
))
3293 if (this->advance_token()->is_op(OPERATOR_RSQUARE
))
3295 go_error_at(this->location(),
3296 "final index required in 3-index slice");
3297 cap
= Expression::make_error(this->location());
3300 cap
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
3302 if (!this->peek_token()->is_op(OPERATOR_RSQUARE
))
3303 go_error_at(this->location(), "missing %<]%>");
3305 this->advance_token();
3306 return Expression::make_index(expr
, start
, end
, cap
, location
);
3309 // Call = "(" [ ArgumentList [ "," ] ] ")" .
3310 // ArgumentList = ExpressionList [ "..." ] .
3313 Parse::call(Expression
* func
)
3315 go_assert(this->peek_token()->is_op(OPERATOR_LPAREN
));
3316 Expression_list
* args
= NULL
;
3317 bool is_varargs
= false;
3318 const Token
* token
= this->advance_token();
3319 if (!token
->is_op(OPERATOR_RPAREN
))
3321 args
= this->expression_list(NULL
, false, true);
3322 token
= this->peek_token();
3323 if (token
->is_op(OPERATOR_ELLIPSIS
))
3326 token
= this->advance_token();
3329 if (token
->is_op(OPERATOR_COMMA
))
3330 token
= this->advance_token();
3331 if (!token
->is_op(OPERATOR_RPAREN
))
3333 go_error_at(this->location(), "missing %<)%>");
3334 if (!this->skip_past_error(OPERATOR_RPAREN
))
3335 return Expression::make_error(this->location());
3337 this->advance_token();
3338 if (func
->is_error_expression())
3340 return Expression::make_call(func
, args
, is_varargs
, func
->location());
3343 // Return an expression for a single unqualified identifier.
3346 Parse::id_to_expression(const std::string
& name
, Location location
,
3349 Named_object
* in_function
;
3350 Named_object
* named_object
= this->gogo_
->lookup(name
, &in_function
);
3351 if (named_object
== NULL
)
3352 named_object
= this->gogo_
->add_unknown_name(name
, location
);
3354 if (in_function
!= NULL
3355 && in_function
!= this->gogo_
->current_function()
3356 && (named_object
->is_variable() || named_object
->is_result_variable()))
3357 return this->enclosing_var_reference(in_function
, named_object
, is_lhs
,
3360 switch (named_object
->classification())
3362 case Named_object::NAMED_OBJECT_CONST
:
3363 return Expression::make_const_reference(named_object
, location
);
3364 case Named_object::NAMED_OBJECT_VAR
:
3365 case Named_object::NAMED_OBJECT_RESULT_VAR
:
3367 this->mark_var_used(named_object
);
3368 return Expression::make_var_reference(named_object
, location
);
3369 case Named_object::NAMED_OBJECT_SINK
:
3370 return Expression::make_sink(location
);
3371 case Named_object::NAMED_OBJECT_FUNC
:
3372 case Named_object::NAMED_OBJECT_FUNC_DECLARATION
:
3373 return Expression::make_func_reference(named_object
, NULL
, location
);
3374 case Named_object::NAMED_OBJECT_UNKNOWN
:
3376 Unknown_expression
* ue
=
3377 Expression::make_unknown_reference(named_object
, location
);
3378 if (this->is_erroneous_function_
)
3379 ue
->set_no_error_message();
3382 case Named_object::NAMED_OBJECT_PACKAGE
:
3383 case Named_object::NAMED_OBJECT_TYPE
:
3384 case Named_object::NAMED_OBJECT_TYPE_DECLARATION
:
3386 // These cases can arise for a field name in a composite
3387 // literal. Keep track of these as they might be fake uses of
3388 // the related package.
3389 Unknown_expression
* ue
=
3390 Expression::make_unknown_reference(named_object
, location
);
3391 if (named_object
->package() != NULL
)
3392 named_object
->package()->note_fake_usage(ue
);
3393 if (this->is_erroneous_function_
)
3394 ue
->set_no_error_message();
3397 case Named_object::NAMED_OBJECT_ERRONEOUS
:
3398 return Expression::make_error(location
);
3400 go_error_at(this->location(), "unexpected type of identifier");
3401 return Expression::make_error(location
);
3405 // Expression = UnaryExpr { binary_op Expression } .
3407 // PRECEDENCE is the precedence of the current operator.
3409 // If MAY_BE_SINK is true, this expression may be "_".
3411 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3414 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3415 // guard (var := expr.("type") using the literal keyword "type").
3417 // If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
3418 // if the entire expression is in parentheses.
3421 Parse::expression(Precedence precedence
, bool may_be_sink
,
3422 bool may_be_composite_lit
, bool* is_type_switch
,
3423 bool *is_parenthesized
)
3425 Expression
* left
= this->unary_expr(may_be_sink
, may_be_composite_lit
,
3426 is_type_switch
, is_parenthesized
);
3430 if (is_type_switch
!= NULL
&& *is_type_switch
)
3433 const Token
* token
= this->peek_token();
3434 if (token
->classification() != Token::TOKEN_OPERATOR
)
3440 Precedence right_precedence
;
3441 switch (token
->op())
3444 right_precedence
= PRECEDENCE_OROR
;
3446 case OPERATOR_ANDAND
:
3447 right_precedence
= PRECEDENCE_ANDAND
;
3450 case OPERATOR_NOTEQ
:
3455 right_precedence
= PRECEDENCE_RELOP
;
3458 case OPERATOR_MINUS
:
3461 right_precedence
= PRECEDENCE_ADDOP
;
3466 case OPERATOR_LSHIFT
:
3467 case OPERATOR_RSHIFT
:
3469 case OPERATOR_BITCLEAR
:
3470 right_precedence
= PRECEDENCE_MULOP
;
3473 right_precedence
= PRECEDENCE_INVALID
;
3477 if (right_precedence
== PRECEDENCE_INVALID
)
3483 if (is_parenthesized
!= NULL
)
3484 *is_parenthesized
= false;
3486 Operator op
= token
->op();
3487 Location binop_location
= token
->location();
3489 if (precedence
>= right_precedence
)
3491 // We've already seen A * B, and we see + C. We want to
3492 // return so that A * B becomes a group.
3496 this->advance_token();
3498 left
= this->verify_not_sink(left
);
3499 Expression
* right
= this->expression(right_precedence
, false,
3500 may_be_composite_lit
,
3502 left
= Expression::make_binary(op
, left
, right
, binop_location
);
3507 Parse::expression_may_start_here()
3509 const Token
* token
= this->peek_token();
3510 switch (token
->classification())
3512 case Token::TOKEN_INVALID
:
3513 case Token::TOKEN_EOF
:
3515 case Token::TOKEN_KEYWORD
:
3516 switch (token
->keyword())
3521 case KEYWORD_STRUCT
:
3522 case KEYWORD_INTERFACE
:
3527 case Token::TOKEN_IDENTIFIER
:
3529 case Token::TOKEN_STRING
:
3531 case Token::TOKEN_OPERATOR
:
3532 switch (token
->op())
3535 case OPERATOR_MINUS
:
3539 case OPERATOR_CHANOP
:
3541 case OPERATOR_LPAREN
:
3542 case OPERATOR_LSQUARE
:
3547 case Token::TOKEN_CHARACTER
:
3548 case Token::TOKEN_INTEGER
:
3549 case Token::TOKEN_FLOAT
:
3550 case Token::TOKEN_IMAGINARY
:
3557 // UnaryExpr = unary_op UnaryExpr | PrimaryExpr .
3559 // If MAY_BE_SINK is true, this expression may be "_".
3561 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3564 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3565 // guard (var := expr.("type") using the literal keyword "type").
3567 // If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
3568 // if the entire expression is in parentheses.
3571 Parse::unary_expr(bool may_be_sink
, bool may_be_composite_lit
,
3572 bool* is_type_switch
, bool* is_parenthesized
)
3574 const Token
* token
= this->peek_token();
3576 // There is a complex parse for <- chan. The choices are
3577 // Convert x to type <- chan int:
3579 // Receive from (x converted to type chan <- chan int):
3580 // (<- chan <- chan int (x))
3581 // Convert x to type <- chan (<- chan int).
3582 // (<- chan <- chan int)(x)
3583 if (token
->is_op(OPERATOR_CHANOP
))
3585 Location location
= token
->location();
3586 if (this->advance_token()->is_keyword(KEYWORD_CHAN
))
3588 Expression
* expr
= this->primary_expr(false, may_be_composite_lit
,
3590 if (expr
->is_error_expression())
3592 else if (!expr
->is_type_expression())
3593 return Expression::make_receive(expr
, location
);
3596 if (expr
->type()->is_error_type())
3599 // We picked up "chan TYPE", but it is not a type
3601 Channel_type
* ct
= expr
->type()->channel_type();
3604 // This is probably impossible.
3605 go_error_at(location
, "expected channel type");
3606 return Expression::make_error(location
);
3608 else if (ct
->may_receive())
3611 Type
* t
= Type::make_channel_type(false, true,
3612 ct
->element_type());
3613 return Expression::make_type(t
, location
);
3617 // <- chan <- TYPE. Because we skipped the leading
3618 // <-, we parsed this as chan <- TYPE. With the
3619 // leading <-, we parse it as <- chan (<- TYPE).
3620 Type
*t
= this->reassociate_chan_direction(ct
, location
);
3621 return Expression::make_type(t
, location
);
3626 this->unget_token(Token::make_operator_token(OPERATOR_CHANOP
, location
));
3627 token
= this->peek_token();
3630 if (token
->is_op(OPERATOR_PLUS
)
3631 || token
->is_op(OPERATOR_MINUS
)
3632 || token
->is_op(OPERATOR_NOT
)
3633 || token
->is_op(OPERATOR_XOR
)
3634 || token
->is_op(OPERATOR_CHANOP
)
3635 || token
->is_op(OPERATOR_MULT
)
3636 || token
->is_op(OPERATOR_AND
))
3638 Location location
= token
->location();
3639 Operator op
= token
->op();
3640 this->advance_token();
3642 Expression
* expr
= this->unary_expr(false, may_be_composite_lit
, NULL
,
3644 if (expr
->is_error_expression())
3646 else if (op
== OPERATOR_MULT
&& expr
->is_type_expression())
3647 expr
= Expression::make_type(Type::make_pointer_type(expr
->type()),
3649 else if (op
== OPERATOR_AND
&& expr
->is_composite_literal())
3650 expr
= Expression::make_heap_expression(expr
, location
);
3651 else if (op
!= OPERATOR_CHANOP
)
3652 expr
= Expression::make_unary(op
, expr
, location
);
3654 expr
= Expression::make_receive(expr
, location
);
3658 return this->primary_expr(may_be_sink
, may_be_composite_lit
,
3659 is_type_switch
, is_parenthesized
);
3662 // This is called for the obscure case of
3663 // (<- chan <- chan int)(x)
3664 // In unary_expr we remove the leading <- and parse the remainder,
3666 // chan <- (chan int)
3667 // When we add the leading <- back in, we really want
3668 // <- chan (<- chan int)
3669 // This means that we need to reassociate.
3672 Parse::reassociate_chan_direction(Channel_type
*ct
, Location location
)
3674 Channel_type
* ele
= ct
->element_type()->channel_type();
3677 go_error_at(location
, "parse error");
3678 return Type::make_error_type();
3681 if (ele
->may_send())
3682 sub
= Type::make_channel_type(false, true, ele
->element_type());
3684 sub
= this->reassociate_chan_direction(ele
, location
);
3685 return Type::make_channel_type(false, true, sub
);
3689 // Declaration | LabeledStmt | SimpleStmt |
3690 // GoStmt | ReturnStmt | BreakStmt | ContinueStmt | GotoStmt |
3691 // FallthroughStmt | Block | IfStmt | SwitchStmt | SelectStmt | ForStmt |
3694 // LABEL is the label of this statement if it has one.
3697 Parse::statement(Label
* label
)
3699 const Token
* token
= this->peek_token();
3700 switch (token
->classification())
3702 case Token::TOKEN_KEYWORD
:
3704 switch (token
->keyword())
3709 this->declaration();
3713 case KEYWORD_STRUCT
:
3714 case KEYWORD_INTERFACE
:
3715 this->simple_stat(true, NULL
, NULL
, NULL
);
3719 this->go_or_defer_stat();
3721 case KEYWORD_RETURN
:
3722 this->return_stat();
3727 case KEYWORD_CONTINUE
:
3728 this->continue_stat();
3736 case KEYWORD_SWITCH
:
3737 this->switch_stat(label
);
3739 case KEYWORD_SELECT
:
3740 this->select_stat(label
);
3743 this->for_stat(label
);
3746 go_error_at(this->location(), "expected statement");
3747 this->advance_token();
3753 case Token::TOKEN_IDENTIFIER
:
3755 std::string identifier
= token
->identifier();
3756 bool is_exported
= token
->is_identifier_exported();
3757 Location location
= token
->location();
3758 if (this->advance_token()->is_op(OPERATOR_COLON
))
3760 this->advance_token();
3761 this->labeled_stmt(identifier
, location
);
3765 this->unget_token(Token::make_identifier_token(identifier
,
3768 this->simple_stat(true, NULL
, NULL
, NULL
);
3773 case Token::TOKEN_OPERATOR
:
3774 if (token
->is_op(OPERATOR_LCURLY
))
3776 Location location
= token
->location();
3777 this->gogo_
->start_block(location
);
3778 Location end_loc
= this->block();
3779 this->gogo_
->add_block(this->gogo_
->finish_block(end_loc
),
3782 else if (!token
->is_op(OPERATOR_SEMICOLON
))
3783 this->simple_stat(true, NULL
, NULL
, NULL
);
3786 case Token::TOKEN_STRING
:
3787 case Token::TOKEN_CHARACTER
:
3788 case Token::TOKEN_INTEGER
:
3789 case Token::TOKEN_FLOAT
:
3790 case Token::TOKEN_IMAGINARY
:
3791 this->simple_stat(true, NULL
, NULL
, NULL
);
3795 go_error_at(this->location(), "expected statement");
3796 this->advance_token();
3802 Parse::statement_may_start_here()
3804 const Token
* token
= this->peek_token();
3805 switch (token
->classification())
3807 case Token::TOKEN_KEYWORD
:
3809 switch (token
->keyword())
3816 case KEYWORD_STRUCT
:
3817 case KEYWORD_INTERFACE
:
3820 case KEYWORD_RETURN
:
3822 case KEYWORD_CONTINUE
:
3825 case KEYWORD_SWITCH
:
3826 case KEYWORD_SELECT
:
3836 case Token::TOKEN_IDENTIFIER
:
3839 case Token::TOKEN_OPERATOR
:
3840 if (token
->is_op(OPERATOR_LCURLY
)
3841 || token
->is_op(OPERATOR_SEMICOLON
))
3844 return this->expression_may_start_here();
3846 case Token::TOKEN_STRING
:
3847 case Token::TOKEN_CHARACTER
:
3848 case Token::TOKEN_INTEGER
:
3849 case Token::TOKEN_FLOAT
:
3850 case Token::TOKEN_IMAGINARY
:
3858 // LabeledStmt = Label ":" Statement .
3859 // Label = identifier .
3862 Parse::labeled_stmt(const std::string
& label_name
, Location location
)
3864 Label
* label
= this->gogo_
->add_label_definition(label_name
, location
);
3866 if (this->peek_token()->is_op(OPERATOR_RCURLY
))
3868 // This is a label at the end of a block. A program is
3869 // permitted to omit a semicolon here.
3873 if (!this->statement_may_start_here())
3875 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH
))
3877 // We don't treat the fallthrough keyword as a statement,
3878 // because it can't appear most places where a statement is
3879 // permitted, but it may have a label. We introduce a
3880 // semicolon because the caller expects to see a statement.
3881 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON
,
3886 // Mark the label as used to avoid a useless error about an
3889 label
->set_is_used();
3891 go_error_at(location
, "missing statement after label");
3892 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON
,
3897 this->statement(label
);
3900 // SimpleStmt = EmptyStmt | ExpressionStmt | SendStmt | IncDecStmt |
3901 // Assignment | ShortVarDecl .
3903 // EmptyStmt was handled in Parse::statement.
3905 // In order to make this work for if and switch statements, if
3906 // RETURN_EXP is not NULL, and we see an ExpressionStat, we return the
3907 // expression rather than adding an expression statement to the
3908 // current block. If we see something other than an ExpressionStat,
3909 // we add the statement, set *RETURN_EXP to true if we saw a send
3910 // statement, and return NULL. The handling of send statements is for
3911 // better error messages.
3913 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
3916 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
3917 // guard (var := expr.("type") using the literal keyword "type").
3920 Parse::simple_stat(bool may_be_composite_lit
, bool* return_exp
,
3921 Range_clause
* p_range_clause
, Type_switch
* p_type_switch
)
3923 const Token
* token
= this->peek_token();
3925 // An identifier follow by := is a SimpleVarDecl.
3926 if (token
->is_identifier())
3928 std::string identifier
= token
->identifier();
3929 bool is_exported
= token
->is_identifier_exported();
3930 Location location
= token
->location();
3932 token
= this->advance_token();
3933 if (token
->is_op(OPERATOR_COLONEQ
)
3934 || token
->is_op(OPERATOR_COMMA
))
3936 identifier
= this->gogo_
->pack_hidden_name(identifier
, is_exported
);
3937 this->simple_var_decl_or_assignment(identifier
, location
,
3938 may_be_composite_lit
,
3940 (token
->is_op(OPERATOR_COLONEQ
)
3946 this->unget_token(Token::make_identifier_token(identifier
, is_exported
,
3949 else if (p_range_clause
!= NULL
&& token
->is_keyword(KEYWORD_RANGE
))
3951 Typed_identifier_list til
;
3952 this->range_clause_decl(&til
, p_range_clause
);
3956 Expression
* exp
= this->expression(PRECEDENCE_NORMAL
, true,
3957 may_be_composite_lit
,
3958 (p_type_switch
== NULL
3960 : &p_type_switch
->found
),
3962 if (p_type_switch
!= NULL
&& p_type_switch
->found
)
3964 p_type_switch
->name
.clear();
3965 p_type_switch
->location
= exp
->location();
3966 p_type_switch
->expr
= this->verify_not_sink(exp
);
3969 token
= this->peek_token();
3970 if (token
->is_op(OPERATOR_CHANOP
))
3972 this->send_stmt(this->verify_not_sink(exp
), may_be_composite_lit
);
3973 if (return_exp
!= NULL
)
3976 else if (token
->is_op(OPERATOR_PLUSPLUS
)
3977 || token
->is_op(OPERATOR_MINUSMINUS
))
3978 this->inc_dec_stat(this->verify_not_sink(exp
));
3979 else if (token
->is_op(OPERATOR_COMMA
)
3980 || token
->is_op(OPERATOR_EQ
))
3981 this->assignment(exp
, may_be_composite_lit
, p_range_clause
);
3982 else if (token
->is_op(OPERATOR_PLUSEQ
)
3983 || token
->is_op(OPERATOR_MINUSEQ
)
3984 || token
->is_op(OPERATOR_OREQ
)
3985 || token
->is_op(OPERATOR_XOREQ
)
3986 || token
->is_op(OPERATOR_MULTEQ
)
3987 || token
->is_op(OPERATOR_DIVEQ
)
3988 || token
->is_op(OPERATOR_MODEQ
)
3989 || token
->is_op(OPERATOR_LSHIFTEQ
)
3990 || token
->is_op(OPERATOR_RSHIFTEQ
)
3991 || token
->is_op(OPERATOR_ANDEQ
)
3992 || token
->is_op(OPERATOR_BITCLEAREQ
))
3993 this->assignment(this->verify_not_sink(exp
), may_be_composite_lit
,
3995 else if (return_exp
!= NULL
)
3996 return this->verify_not_sink(exp
);
3999 exp
= this->verify_not_sink(exp
);
4001 if (token
->is_op(OPERATOR_COLONEQ
))
4003 if (!exp
->is_error_expression())
4004 go_error_at(token
->location(), "non-name on left side of %<:=%>");
4005 this->gogo_
->mark_locals_used();
4006 while (!token
->is_op(OPERATOR_SEMICOLON
)
4007 && !token
->is_eof())
4008 token
= this->advance_token();
4012 this->expression_stat(exp
);
4019 Parse::simple_stat_may_start_here()
4021 return this->expression_may_start_here();
4024 // Parse { Statement ";" } which is used in a few places. The list of
4025 // statements may end with a right curly brace, in which case the
4026 // semicolon may be omitted.
4029 Parse::statement_list()
4031 while (this->statement_may_start_here())
4033 this->statement(NULL
);
4034 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4035 this->advance_token();
4036 else if (this->peek_token()->is_op(OPERATOR_RCURLY
))
4040 if (!this->peek_token()->is_eof() || !saw_errors())
4041 go_error_at(this->location(), "expected %<;%> or %<}%> or newline");
4042 if (!this->skip_past_error(OPERATOR_RCURLY
))
4049 Parse::statement_list_may_start_here()
4051 return this->statement_may_start_here();
4054 // ExpressionStat = Expression .
4057 Parse::expression_stat(Expression
* exp
)
4059 this->gogo_
->add_statement(Statement::make_statement(exp
, false));
4062 // SendStmt = Channel "<-" Expression .
4063 // Channel = Expression .
4066 Parse::send_stmt(Expression
* channel
, bool may_be_composite_lit
)
4068 go_assert(this->peek_token()->is_op(OPERATOR_CHANOP
));
4069 Location loc
= this->location();
4070 this->advance_token();
4071 Expression
* val
= this->expression(PRECEDENCE_NORMAL
, false,
4072 may_be_composite_lit
, NULL
, NULL
);
4073 Statement
* s
= Statement::make_send_statement(channel
, val
, loc
);
4074 this->gogo_
->add_statement(s
);
4077 // IncDecStat = Expression ( "++" | "--" ) .
4080 Parse::inc_dec_stat(Expression
* exp
)
4082 const Token
* token
= this->peek_token();
4083 if (token
->is_op(OPERATOR_PLUSPLUS
))
4084 this->gogo_
->add_statement(Statement::make_inc_statement(exp
));
4085 else if (token
->is_op(OPERATOR_MINUSMINUS
))
4086 this->gogo_
->add_statement(Statement::make_dec_statement(exp
));
4089 this->advance_token();
4092 // Assignment = ExpressionList assign_op ExpressionList .
4094 // EXP is an expression that we have already parsed.
4096 // If MAY_BE_COMPOSITE_LIT is true, an expression on the right hand
4097 // side may be a composite literal.
4099 // If RANGE_CLAUSE is not NULL, then this will recognize a
4103 Parse::assignment(Expression
* expr
, bool may_be_composite_lit
,
4104 Range_clause
* p_range_clause
)
4106 Expression_list
* vars
;
4107 if (!this->peek_token()->is_op(OPERATOR_COMMA
))
4109 vars
= new Expression_list();
4110 vars
->push_back(expr
);
4114 this->advance_token();
4115 vars
= this->expression_list(expr
, true, may_be_composite_lit
);
4118 this->tuple_assignment(vars
, may_be_composite_lit
, p_range_clause
);
4121 // An assignment statement. LHS is the list of expressions which
4122 // appear on the left hand side.
4124 // If MAY_BE_COMPOSITE_LIT is true, an expression on the right hand
4125 // side may be a composite literal.
4127 // If RANGE_CLAUSE is not NULL, then this will recognize a
4131 Parse::tuple_assignment(Expression_list
* lhs
, bool may_be_composite_lit
,
4132 Range_clause
* p_range_clause
)
4134 const Token
* token
= this->peek_token();
4135 if (!token
->is_op(OPERATOR_EQ
)
4136 && !token
->is_op(OPERATOR_PLUSEQ
)
4137 && !token
->is_op(OPERATOR_MINUSEQ
)
4138 && !token
->is_op(OPERATOR_OREQ
)
4139 && !token
->is_op(OPERATOR_XOREQ
)
4140 && !token
->is_op(OPERATOR_MULTEQ
)
4141 && !token
->is_op(OPERATOR_DIVEQ
)
4142 && !token
->is_op(OPERATOR_MODEQ
)
4143 && !token
->is_op(OPERATOR_LSHIFTEQ
)
4144 && !token
->is_op(OPERATOR_RSHIFTEQ
)
4145 && !token
->is_op(OPERATOR_ANDEQ
)
4146 && !token
->is_op(OPERATOR_BITCLEAREQ
))
4148 go_error_at(this->location(), "expected assignment operator");
4151 Operator op
= token
->op();
4152 Location location
= token
->location();
4154 token
= this->advance_token();
4159 if (p_range_clause
!= NULL
&& token
->is_keyword(KEYWORD_RANGE
))
4161 if (op
!= OPERATOR_EQ
)
4162 go_error_at(this->location(), "range clause requires %<=%>");
4163 this->range_clause_expr(lhs
, p_range_clause
);
4167 Expression_list
* vals
= this->expression_list(NULL
, false,
4168 may_be_composite_lit
);
4170 // We've parsed everything; check for errors.
4173 for (Expression_list::const_iterator pe
= lhs
->begin();
4177 if ((*pe
)->is_error_expression())
4179 if (op
!= OPERATOR_EQ
&& (*pe
)->is_sink_expression())
4180 go_error_at((*pe
)->location(), "cannot use _ as value");
4182 for (Expression_list::const_iterator pe
= vals
->begin();
4186 if ((*pe
)->is_error_expression())
4190 Call_expression
* call
;
4191 Index_expression
* map_index
;
4192 Receive_expression
* receive
;
4193 Type_guard_expression
* type_guard
;
4194 if (lhs
->size() == vals
->size())
4197 if (lhs
->size() > 1)
4199 if (op
!= OPERATOR_EQ
)
4200 go_error_at(location
, "multiple values only permitted with %<=%>");
4201 s
= Statement::make_tuple_assignment(lhs
, vals
, location
);
4205 if (op
== OPERATOR_EQ
)
4206 s
= Statement::make_assignment(lhs
->front(), vals
->front(),
4209 s
= Statement::make_assignment_operation(op
, lhs
->front(),
4210 vals
->front(), location
);
4214 this->gogo_
->add_statement(s
);
4216 else if (vals
->size() == 1
4217 && (call
= (*vals
->begin())->call_expression()) != NULL
)
4219 if (op
!= OPERATOR_EQ
)
4220 go_error_at(location
, "multiple results only permitted with %<=%>");
4221 call
->set_expected_result_count(lhs
->size());
4223 vals
= new Expression_list
;
4224 for (unsigned int i
= 0; i
< lhs
->size(); ++i
)
4225 vals
->push_back(Expression::make_call_result(call
, i
));
4226 Statement
* s
= Statement::make_tuple_assignment(lhs
, vals
, location
);
4227 this->gogo_
->add_statement(s
);
4229 else if (lhs
->size() == 2
4230 && vals
->size() == 1
4231 && (map_index
= (*vals
->begin())->index_expression()) != NULL
)
4233 if (op
!= OPERATOR_EQ
)
4234 go_error_at(location
, "two values from map requires %<=%>");
4235 Expression
* val
= lhs
->front();
4236 Expression
* present
= lhs
->back();
4237 Statement
* s
= Statement::make_tuple_map_assignment(val
, present
,
4238 map_index
, location
);
4239 this->gogo_
->add_statement(s
);
4241 else if (lhs
->size() == 2
4242 && vals
->size() == 1
4243 && (receive
= (*vals
->begin())->receive_expression()) != NULL
)
4245 if (op
!= OPERATOR_EQ
)
4246 go_error_at(location
, "two values from receive requires %<=%>");
4247 Expression
* val
= lhs
->front();
4248 Expression
* success
= lhs
->back();
4249 Expression
* channel
= receive
->channel();
4250 Statement
* s
= Statement::make_tuple_receive_assignment(val
, success
,
4253 this->gogo_
->add_statement(s
);
4255 else if (lhs
->size() == 2
4256 && vals
->size() == 1
4257 && (type_guard
= (*vals
->begin())->type_guard_expression()) != NULL
)
4259 if (op
!= OPERATOR_EQ
)
4260 go_error_at(location
, "two values from type guard requires %<=%>");
4261 Expression
* val
= lhs
->front();
4262 Expression
* ok
= lhs
->back();
4263 Expression
* expr
= type_guard
->expr();
4264 Type
* type
= type_guard
->type();
4265 Statement
* s
= Statement::make_tuple_type_guard_assignment(val
, ok
,
4268 this->gogo_
->add_statement(s
);
4272 go_error_at(location
, ("number of variables does not "
4273 "match number of values"));
4277 // GoStat = "go" Expression .
4278 // DeferStat = "defer" Expression .
4281 Parse::go_or_defer_stat()
4283 go_assert(this->peek_token()->is_keyword(KEYWORD_GO
)
4284 || this->peek_token()->is_keyword(KEYWORD_DEFER
));
4285 bool is_go
= this->peek_token()->is_keyword(KEYWORD_GO
);
4286 Location stat_location
= this->location();
4288 this->advance_token();
4289 Location expr_location
= this->location();
4291 bool is_parenthesized
= false;
4292 Expression
* expr
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
,
4294 Call_expression
* call_expr
= expr
->call_expression();
4295 if (is_parenthesized
|| call_expr
== NULL
)
4297 go_error_at(expr_location
, "argument to go/defer must be function call");
4301 // Make it easier to simplify go/defer statements by putting every
4302 // statement in its own block.
4303 this->gogo_
->start_block(stat_location
);
4306 stat
= Statement::make_go_statement(call_expr
, stat_location
);
4308 stat
= Statement::make_defer_statement(call_expr
, stat_location
);
4309 this->gogo_
->add_statement(stat
);
4310 this->gogo_
->add_block(this->gogo_
->finish_block(stat_location
),
4314 // ReturnStat = "return" [ ExpressionList ] .
4317 Parse::return_stat()
4319 go_assert(this->peek_token()->is_keyword(KEYWORD_RETURN
));
4320 Location location
= this->location();
4321 this->advance_token();
4322 Expression_list
* vals
= NULL
;
4323 if (this->expression_may_start_here())
4324 vals
= this->expression_list(NULL
, false, true);
4325 this->gogo_
->add_statement(Statement::make_return_statement(vals
, location
));
4328 && this->gogo_
->current_function()->func_value()->results_are_named())
4330 Named_object
* function
= this->gogo_
->current_function();
4331 Function::Results
* results
= function
->func_value()->result_variables();
4332 for (Function::Results::const_iterator p
= results
->begin();
4333 p
!= results
->end();
4336 Named_object
* no
= this->gogo_
->lookup((*p
)->name(), NULL
);
4338 go_assert(saw_errors());
4339 else if (!no
->is_result_variable())
4340 go_error_at(location
, "%qs is shadowed during return",
4341 (*p
)->message_name().c_str());
4346 // IfStmt = "if" [ SimpleStmt ";" ] Expression Block
4347 // [ "else" ( IfStmt | Block ) ] .
4352 go_assert(this->peek_token()->is_keyword(KEYWORD_IF
));
4353 Location location
= this->location();
4354 this->advance_token();
4356 this->gogo_
->start_block(location
);
4358 bool saw_simple_stat
= false;
4359 Expression
* cond
= NULL
;
4360 bool saw_send_stmt
= false;
4361 if (this->simple_stat_may_start_here())
4363 cond
= this->simple_stat(false, &saw_send_stmt
, NULL
, NULL
);
4364 saw_simple_stat
= true;
4366 if (cond
!= NULL
&& this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4368 // The SimpleStat is an expression statement.
4369 this->expression_stat(cond
);
4374 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4375 this->advance_token();
4376 else if (saw_simple_stat
)
4379 go_error_at(this->location(),
4380 ("send statement used as value; "
4381 "use select for non-blocking send"));
4383 go_error_at(this->location(),
4384 "expected %<;%> after statement in if expression");
4385 if (!this->expression_may_start_here())
4386 cond
= Expression::make_error(this->location());
4388 if (cond
== NULL
&& this->peek_token()->is_op(OPERATOR_LCURLY
))
4390 go_error_at(this->location(),
4391 "missing condition in if statement");
4392 cond
= Expression::make_error(this->location());
4395 cond
= this->expression(PRECEDENCE_NORMAL
, false, false, NULL
, NULL
);
4398 // Check for the easy error of a newline before starting the block.
4399 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4401 Location semi_loc
= this->location();
4402 if (this->advance_token()->is_op(OPERATOR_LCURLY
))
4403 go_error_at(semi_loc
, "missing %<{%> after if clause");
4404 // Otherwise we will get an error when we call this->block
4408 this->gogo_
->start_block(this->location());
4409 Location end_loc
= this->block();
4410 Block
* then_block
= this->gogo_
->finish_block(end_loc
);
4412 // Check for the easy error of a newline before "else".
4413 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4415 Location semi_loc
= this->location();
4416 if (this->advance_token()->is_keyword(KEYWORD_ELSE
))
4417 go_error_at(this->location(),
4418 "unexpected semicolon or newline before %<else%>");
4420 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON
,
4424 Block
* else_block
= NULL
;
4425 if (this->peek_token()->is_keyword(KEYWORD_ELSE
))
4427 this->gogo_
->start_block(this->location());
4428 const Token
* token
= this->advance_token();
4429 if (token
->is_keyword(KEYWORD_IF
))
4431 else if (token
->is_op(OPERATOR_LCURLY
))
4435 go_error_at(this->location(), "expected %<if%> or %<{%>");
4436 this->statement(NULL
);
4438 else_block
= this->gogo_
->finish_block(this->location());
4441 this->gogo_
->add_statement(Statement::make_if_statement(cond
, then_block
,
4445 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4449 // SwitchStmt = ExprSwitchStmt | TypeSwitchStmt .
4450 // ExprSwitchStmt = "switch" [ [ SimpleStat ] ";" ] [ Expression ]
4451 // "{" { ExprCaseClause } "}" .
4452 // TypeSwitchStmt = "switch" [ [ SimpleStat ] ";" ] TypeSwitchGuard
4453 // "{" { TypeCaseClause } "}" .
4454 // TypeSwitchGuard = [ identifier ":=" ] Expression "." "(" "type" ")" .
4457 Parse::switch_stat(Label
* label
)
4459 go_assert(this->peek_token()->is_keyword(KEYWORD_SWITCH
));
4460 Location location
= this->location();
4461 this->advance_token();
4463 this->gogo_
->start_block(location
);
4465 bool saw_simple_stat
= false;
4466 Expression
* switch_val
= NULL
;
4468 Type_switch type_switch
;
4469 bool have_type_switch_block
= false;
4470 if (this->simple_stat_may_start_here())
4472 switch_val
= this->simple_stat(false, &saw_send_stmt
, NULL
,
4474 saw_simple_stat
= true;
4476 if (switch_val
!= NULL
&& this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4478 // The SimpleStat is an expression statement.
4479 this->expression_stat(switch_val
);
4482 if (switch_val
== NULL
&& !type_switch
.found
)
4484 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4485 this->advance_token();
4486 else if (saw_simple_stat
)
4489 go_error_at(this->location(),
4490 ("send statement used as value; "
4491 "use select for non-blocking send"));
4493 go_error_at(this->location(),
4494 "expected %<;%> after statement in switch expression");
4496 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
4498 if (this->peek_token()->is_identifier())
4500 const Token
* token
= this->peek_token();
4501 std::string identifier
= token
->identifier();
4502 bool is_exported
= token
->is_identifier_exported();
4503 Location id_loc
= token
->location();
4505 token
= this->advance_token();
4506 bool is_coloneq
= token
->is_op(OPERATOR_COLONEQ
);
4507 this->unget_token(Token::make_identifier_token(identifier
,
4512 // This must be a TypeSwitchGuard. It is in a
4513 // different block from any initial SimpleStat.
4514 if (saw_simple_stat
)
4516 this->gogo_
->start_block(id_loc
);
4517 have_type_switch_block
= true;
4520 switch_val
= this->simple_stat(false, &saw_send_stmt
, NULL
,
4522 if (!type_switch
.found
)
4524 if (switch_val
== NULL
4525 || !switch_val
->is_error_expression())
4528 "expected type switch assignment");
4529 switch_val
= Expression::make_error(id_loc
);
4534 if (switch_val
== NULL
&& !type_switch
.found
)
4536 switch_val
= this->expression(PRECEDENCE_NORMAL
, false, false,
4537 &type_switch
.found
, NULL
);
4538 if (type_switch
.found
)
4540 type_switch
.name
.clear();
4541 type_switch
.expr
= switch_val
;
4542 type_switch
.location
= switch_val
->location();
4548 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
4550 Location token_loc
= this->location();
4551 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
)
4552 && this->advance_token()->is_op(OPERATOR_LCURLY
))
4553 go_error_at(token_loc
, "missing %<{%> after switch clause");
4554 else if (this->peek_token()->is_op(OPERATOR_COLONEQ
))
4556 go_error_at(token_loc
, "invalid variable name");
4557 this->advance_token();
4558 this->expression(PRECEDENCE_NORMAL
, false, false,
4559 &type_switch
.found
, NULL
);
4560 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
4561 this->advance_token();
4562 if (!this->peek_token()->is_op(OPERATOR_LCURLY
))
4564 if (have_type_switch_block
)
4565 this->gogo_
->add_block(this->gogo_
->finish_block(location
),
4567 this->gogo_
->add_block(this->gogo_
->finish_block(location
),
4571 if (type_switch
.found
)
4572 type_switch
.expr
= Expression::make_error(location
);
4576 go_error_at(this->location(), "expected %<{%>");
4577 if (have_type_switch_block
)
4578 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4580 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4585 this->advance_token();
4587 Statement
* statement
;
4588 if (type_switch
.found
)
4589 statement
= this->type_switch_body(label
, type_switch
, location
);
4591 statement
= this->expr_switch_body(label
, switch_val
, location
);
4593 if (statement
!= NULL
)
4594 this->gogo_
->add_statement(statement
);
4596 if (have_type_switch_block
)
4597 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4600 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
4604 // The body of an expression switch.
4605 // "{" { ExprCaseClause } "}"
4608 Parse::expr_switch_body(Label
* label
, Expression
* switch_val
,
4611 Switch_statement
* statement
= Statement::make_switch_statement(switch_val
,
4614 this->push_break_statement(statement
, label
);
4616 Case_clauses
* case_clauses
= new Case_clauses();
4617 bool saw_default
= false;
4618 while (!this->peek_token()->is_op(OPERATOR_RCURLY
))
4620 if (this->peek_token()->is_eof())
4623 go_error_at(this->location(), "missing %<}%>");
4626 this->expr_case_clause(case_clauses
, &saw_default
);
4628 this->advance_token();
4630 statement
->add_clauses(case_clauses
);
4632 this->pop_break_statement();
4637 // ExprCaseClause = ExprSwitchCase ":" [ StatementList ] .
4638 // FallthroughStat = "fallthrough" .
4641 Parse::expr_case_clause(Case_clauses
* clauses
, bool* saw_default
)
4643 Location location
= this->location();
4645 bool is_default
= false;
4646 Expression_list
* vals
= this->expr_switch_case(&is_default
);
4648 if (!this->peek_token()->is_op(OPERATOR_COLON
))
4651 go_error_at(this->location(), "expected %<:%>");
4655 this->advance_token();
4657 Block
* statements
= NULL
;
4658 if (this->statement_list_may_start_here())
4660 this->gogo_
->start_block(this->location());
4661 this->statement_list();
4662 statements
= this->gogo_
->finish_block(this->location());
4665 bool is_fallthrough
= false;
4666 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH
))
4668 Location fallthrough_loc
= this->location();
4669 is_fallthrough
= true;
4670 if (this->advance_token()->is_op(OPERATOR_SEMICOLON
))
4671 this->advance_token();
4672 if (this->peek_token()->is_op(OPERATOR_RCURLY
))
4673 go_error_at(fallthrough_loc
,
4674 _("cannot fallthrough final case in switch"));
4681 go_error_at(location
, "multiple defaults in switch");
4684 *saw_default
= true;
4687 if (is_default
|| vals
!= NULL
)
4688 clauses
->add(vals
, is_default
, statements
, is_fallthrough
, location
);
4691 // ExprSwitchCase = "case" ExpressionList | "default" .
4694 Parse::expr_switch_case(bool* is_default
)
4696 const Token
* token
= this->peek_token();
4697 if (token
->is_keyword(KEYWORD_CASE
))
4699 this->advance_token();
4700 return this->expression_list(NULL
, false, true);
4702 else if (token
->is_keyword(KEYWORD_DEFAULT
))
4704 this->advance_token();
4711 go_error_at(this->location(), "expected %<case%> or %<default%>");
4712 if (!token
->is_op(OPERATOR_RCURLY
))
4713 this->advance_token();
4718 // The body of a type switch.
4719 // "{" { TypeCaseClause } "}" .
4722 Parse::type_switch_body(Label
* label
, const Type_switch
& type_switch
,
4725 Expression
* init
= type_switch
.expr
;
4726 std::string var_name
= type_switch
.name
;
4727 if (!var_name
.empty())
4729 if (Gogo::is_sink_name(var_name
))
4731 go_error_at(type_switch
.location
,
4732 "no new variables on left side of %<:=%>");
4737 Location loc
= type_switch
.location
;
4738 Temporary_statement
* switch_temp
=
4739 Statement::make_temporary(NULL
, init
, loc
);
4740 this->gogo_
->add_statement(switch_temp
);
4741 init
= Expression::make_temporary_reference(switch_temp
, loc
);
4745 Type_switch_statement
* statement
=
4746 Statement::make_type_switch_statement(var_name
, init
, location
);
4747 this->push_break_statement(statement
, label
);
4749 Type_case_clauses
* case_clauses
= new Type_case_clauses();
4750 bool saw_default
= false;
4751 std::vector
<Named_object
*> implicit_vars
;
4752 while (!this->peek_token()->is_op(OPERATOR_RCURLY
))
4754 if (this->peek_token()->is_eof())
4756 go_error_at(this->location(), "missing %<}%>");
4759 this->type_case_clause(var_name
, init
, case_clauses
, &saw_default
,
4762 this->advance_token();
4764 statement
->add_clauses(case_clauses
);
4766 this->pop_break_statement();
4768 // If there is a type switch variable implicitly declared in each case clause,
4769 // check that it is used in at least one of the cases.
4770 if (!var_name
.empty())
4773 for (std::vector
<Named_object
*>::iterator p
= implicit_vars
.begin();
4774 p
!= implicit_vars
.end();
4777 if ((*p
)->var_value()->is_used())
4784 go_error_at(type_switch
.location
, "%qs declared and not used",
4785 Gogo::message_name(var_name
).c_str());
4790 // TypeCaseClause = TypeSwitchCase ":" [ StatementList ] .
4791 // IMPLICIT_VARS is the list of variables implicitly declared for each type
4792 // case if there is a type switch variable declared.
4795 Parse::type_case_clause(const std::string
& var_name
, Expression
* init
,
4796 Type_case_clauses
* clauses
, bool* saw_default
,
4797 std::vector
<Named_object
*>* implicit_vars
)
4799 Location location
= this->location();
4801 std::vector
<Type
*> types
;
4802 bool is_default
= false;
4803 this->type_switch_case(&types
, &is_default
);
4805 if (!this->peek_token()->is_op(OPERATOR_COLON
))
4806 go_error_at(this->location(), "expected %<:%>");
4808 this->advance_token();
4810 Block
* statements
= NULL
;
4811 if (this->statement_list_may_start_here())
4813 this->gogo_
->start_block(this->location());
4814 if (!var_name
.empty())
4817 Location var_loc
= init
->location();
4818 if (types
.size() == 1)
4820 type
= types
.front();
4821 init
= Expression::make_type_guard(init
, type
, location
);
4824 Variable
* v
= new Variable(type
, init
, false, false, false,
4827 v
->set_is_type_switch_var();
4828 implicit_vars
->push_back(this->gogo_
->add_variable(var_name
, v
));
4830 this->statement_list();
4831 statements
= this->gogo_
->finish_block(this->location());
4834 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH
))
4836 go_error_at(this->location(),
4837 "fallthrough is not permitted in a type switch");
4838 if (this->advance_token()->is_op(OPERATOR_SEMICOLON
))
4839 this->advance_token();
4844 go_assert(types
.empty());
4847 go_error_at(location
, "multiple defaults in type switch");
4850 *saw_default
= true;
4851 clauses
->add(NULL
, false, true, statements
, location
);
4853 else if (!types
.empty())
4855 for (std::vector
<Type
*>::const_iterator p
= types
.begin();
4856 p
+ 1 != types
.end();
4858 clauses
->add(*p
, true, false, NULL
, location
);
4859 clauses
->add(types
.back(), false, false, statements
, location
);
4862 clauses
->add(Type::make_error_type(), false, false, statements
, location
);
4865 // TypeSwitchCase = "case" type | "default"
4867 // We accept a comma separated list of types.
4870 Parse::type_switch_case(std::vector
<Type
*>* types
, bool* is_default
)
4872 const Token
* token
= this->peek_token();
4873 if (token
->is_keyword(KEYWORD_CASE
))
4875 this->advance_token();
4878 Type
* t
= this->type();
4880 if (!t
->is_error_type())
4881 types
->push_back(t
);
4884 this->gogo_
->mark_locals_used();
4885 token
= this->peek_token();
4886 while (!token
->is_op(OPERATOR_COLON
)
4887 && !token
->is_op(OPERATOR_COMMA
)
4888 && !token
->is_op(OPERATOR_RCURLY
)
4889 && !token
->is_eof())
4890 token
= this->advance_token();
4893 if (!this->peek_token()->is_op(OPERATOR_COMMA
))
4895 this->advance_token();
4898 else if (token
->is_keyword(KEYWORD_DEFAULT
))
4900 this->advance_token();
4905 go_error_at(this->location(), "expected %<case%> or %<default%>");
4906 if (!token
->is_op(OPERATOR_RCURLY
))
4907 this->advance_token();
4911 // SelectStat = "select" "{" { CommClause } "}" .
4914 Parse::select_stat(Label
* label
)
4916 go_assert(this->peek_token()->is_keyword(KEYWORD_SELECT
));
4917 Location location
= this->location();
4918 const Token
* token
= this->advance_token();
4920 if (!token
->is_op(OPERATOR_LCURLY
))
4922 Location token_loc
= token
->location();
4923 if (token
->is_op(OPERATOR_SEMICOLON
)
4924 && this->advance_token()->is_op(OPERATOR_LCURLY
))
4925 go_error_at(token_loc
, "unexpected semicolon or newline before %<{%>");
4928 go_error_at(this->location(), "expected %<{%>");
4932 this->advance_token();
4934 Select_statement
* statement
= Statement::make_select_statement(location
);
4936 this->push_break_statement(statement
, label
);
4938 Select_clauses
* select_clauses
= new Select_clauses();
4939 bool saw_default
= false;
4940 while (!this->peek_token()->is_op(OPERATOR_RCURLY
))
4942 if (this->peek_token()->is_eof())
4944 go_error_at(this->location(), "expected %<}%>");
4947 this->comm_clause(select_clauses
, &saw_default
);
4950 this->advance_token();
4952 statement
->add_clauses(select_clauses
);
4954 this->pop_break_statement();
4956 this->gogo_
->add_statement(statement
);
4959 // CommClause = CommCase ":" { Statement ";" } .
4962 Parse::comm_clause(Select_clauses
* clauses
, bool* saw_default
)
4964 Location location
= this->location();
4965 bool is_send
= false;
4966 Expression
* channel
= NULL
;
4967 Expression
* val
= NULL
;
4968 Expression
* closed
= NULL
;
4969 std::string varname
;
4970 std::string closedname
;
4971 bool is_default
= false;
4972 bool got_case
= this->comm_case(&is_send
, &channel
, &val
, &closed
,
4973 &varname
, &closedname
, &is_default
);
4975 if (this->peek_token()->is_op(OPERATOR_COLON
))
4976 this->advance_token();
4978 go_error_at(this->location(), "expected colon");
4980 this->gogo_
->start_block(this->location());
4982 Named_object
* var
= NULL
;
4983 if (!varname
.empty())
4985 // FIXME: LOCATION is slightly wrong here.
4986 Variable
* v
= new Variable(NULL
, channel
, false, false, false,
4988 v
->set_type_from_chan_element();
4989 var
= this->gogo_
->add_variable(varname
, v
);
4992 Named_object
* closedvar
= NULL
;
4993 if (!closedname
.empty())
4995 // FIXME: LOCATION is slightly wrong here.
4996 Variable
* v
= new Variable(Type::lookup_bool_type(), NULL
,
4997 false, false, false, location
);
4998 closedvar
= this->gogo_
->add_variable(closedname
, v
);
5001 this->statement_list();
5003 Block
* statements
= this->gogo_
->finish_block(this->location());
5009 go_error_at(location
, "multiple defaults in select");
5012 *saw_default
= true;
5016 clauses
->add(is_send
, channel
, val
, closed
, var
, closedvar
, is_default
,
5017 statements
, location
);
5018 else if (statements
!= NULL
)
5020 // Add the statements to make sure that any names they define
5022 this->gogo_
->add_block(statements
, location
);
5026 // CommCase = "case" ( SendStmt | RecvStmt ) | "default" .
5029 Parse::comm_case(bool* is_send
, Expression
** channel
, Expression
** val
,
5030 Expression
** closed
, std::string
* varname
,
5031 std::string
* closedname
, bool* is_default
)
5033 const Token
* token
= this->peek_token();
5034 if (token
->is_keyword(KEYWORD_DEFAULT
))
5036 this->advance_token();
5039 else if (token
->is_keyword(KEYWORD_CASE
))
5041 this->advance_token();
5042 if (!this->send_or_recv_stmt(is_send
, channel
, val
, closed
, varname
,
5048 go_error_at(this->location(), "expected %<case%> or %<default%>");
5049 if (!token
->is_op(OPERATOR_RCURLY
))
5050 this->advance_token();
5057 // RecvStmt = [ Expression [ "," Expression ] ( "=" | ":=" ) ] RecvExpr .
5058 // RecvExpr = Expression .
5061 Parse::send_or_recv_stmt(bool* is_send
, Expression
** channel
, Expression
** val
,
5062 Expression
** closed
, std::string
* varname
,
5063 std::string
* closedname
)
5065 const Token
* token
= this->peek_token();
5066 bool saw_comma
= false;
5067 bool closed_is_id
= false;
5068 if (token
->is_identifier())
5070 Gogo
* gogo
= this->gogo_
;
5071 std::string recv_var
= token
->identifier();
5072 bool is_rv_exported
= token
->is_identifier_exported();
5073 Location recv_var_loc
= token
->location();
5074 token
= this->advance_token();
5075 if (token
->is_op(OPERATOR_COLONEQ
))
5078 this->advance_token();
5079 Expression
* e
= this->expression(PRECEDENCE_NORMAL
, false, false,
5081 Receive_expression
* re
= e
->receive_expression();
5084 if (!e
->is_error_expression())
5085 go_error_at(this->location(), "expected receive expression");
5088 if (recv_var
== "_")
5090 go_error_at(recv_var_loc
,
5091 "no new variables on left side of %<:=%>");
5092 recv_var
= Gogo::erroneous_name();
5095 *varname
= gogo
->pack_hidden_name(recv_var
, is_rv_exported
);
5096 *channel
= re
->channel();
5099 else if (token
->is_op(OPERATOR_COMMA
))
5101 token
= this->advance_token();
5102 if (token
->is_identifier())
5104 std::string recv_closed
= token
->identifier();
5105 bool is_rc_exported
= token
->is_identifier_exported();
5106 Location recv_closed_loc
= token
->location();
5107 closed_is_id
= true;
5109 token
= this->advance_token();
5110 if (token
->is_op(OPERATOR_COLONEQ
))
5112 // case rv, rc := <-c:
5113 this->advance_token();
5114 Expression
* e
= this->expression(PRECEDENCE_NORMAL
, false,
5116 Receive_expression
* re
= e
->receive_expression();
5119 if (!e
->is_error_expression())
5120 go_error_at(this->location(),
5121 "expected receive expression");
5124 if (recv_var
== "_" && recv_closed
== "_")
5126 go_error_at(recv_var_loc
,
5127 "no new variables on left side of %<:=%>");
5128 recv_var
= Gogo::erroneous_name();
5131 if (recv_var
!= "_")
5132 *varname
= gogo
->pack_hidden_name(recv_var
,
5134 if (recv_closed
!= "_")
5135 *closedname
= gogo
->pack_hidden_name(recv_closed
,
5137 *channel
= re
->channel();
5141 this->unget_token(Token::make_identifier_token(recv_closed
,
5146 *val
= this->id_to_expression(gogo
->pack_hidden_name(recv_var
,
5148 recv_var_loc
, true);
5152 this->unget_token(Token::make_identifier_token(recv_var
,
5157 // If SAW_COMMA is false, then we are looking at the start of the
5158 // send or receive expression. If SAW_COMMA is true, then *VAL is
5159 // set and we just read a comma.
5162 if (saw_comma
|| !this->peek_token()->is_op(OPERATOR_CHANOP
))
5163 e
= this->expression(PRECEDENCE_NORMAL
, true, true, NULL
, NULL
);
5168 this->advance_token();
5169 *channel
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
5171 // The next token should be ':'. If it is '<-', then we have
5173 // which is to say, send on a channel received from a channel.
5174 if (!this->peek_token()->is_op(OPERATOR_CHANOP
))
5177 e
= Expression::make_receive(*channel
, (*channel
)->location());
5180 if (!saw_comma
&& this->peek_token()->is_op(OPERATOR_COMMA
))
5182 this->advance_token();
5184 if (!e
->is_sink_expression())
5186 e
= this->expression(PRECEDENCE_NORMAL
, true, true, NULL
, NULL
);
5190 if (this->peek_token()->is_op(OPERATOR_EQ
))
5192 if (!this->advance_token()->is_op(OPERATOR_CHANOP
))
5194 go_error_at(this->location(), "missing %<<-%>");
5198 this->advance_token();
5199 *channel
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
5203 // *VAL is already set.
5204 if (!e
->is_sink_expression())
5210 if (!e
->is_sink_expression())
5219 go_error_at(this->location(), "expected %<=%> or %<:=%>");
5221 go_error_at(this->location(), "expected %<=%>");
5225 if (this->peek_token()->is_op(OPERATOR_CHANOP
))
5229 *channel
= this->verify_not_sink(e
);
5230 this->advance_token();
5231 *val
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
5235 go_error_at(this->location(), "expected %<<-%> or %<=%>");
5239 // ForStat = "for" [ Condition | ForClause | RangeClause ] Block .
5240 // Condition = Expression .
5243 Parse::for_stat(Label
* label
)
5245 go_assert(this->peek_token()->is_keyword(KEYWORD_FOR
));
5246 Location location
= this->location();
5247 const Token
* token
= this->advance_token();
5249 // Open a block to hold any variables defined in the init statement
5250 // of the for statement.
5251 this->gogo_
->start_block(location
);
5254 Expression
* cond
= NULL
;
5256 Range_clause range_clause
;
5258 if (!token
->is_op(OPERATOR_LCURLY
))
5260 if (token
->is_keyword(KEYWORD_VAR
))
5262 go_error_at(this->location(),
5263 "var declaration not allowed in for initializer");
5267 if (token
->is_op(OPERATOR_SEMICOLON
))
5268 this->for_clause(&cond
, &post
);
5271 // We might be looking at a Condition, an InitStat, or a
5274 cond
= this->simple_stat(false, &saw_send_stmt
, &range_clause
, NULL
);
5275 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5277 if (cond
== NULL
&& !range_clause
.found
)
5280 go_error_at(this->location(),
5281 ("send statement used as value; "
5282 "use select for non-blocking send"));
5284 go_error_at(this->location(),
5285 "parse error in for statement");
5290 if (range_clause
.found
)
5291 go_error_at(this->location(), "parse error after range clause");
5295 // COND is actually an expression statement for
5296 // InitStat at the start of a ForClause.
5297 this->expression_stat(cond
);
5301 this->for_clause(&cond
, &post
);
5306 // Check for the easy error of a newline before starting the block.
5307 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5309 Location semi_loc
= this->location();
5310 if (this->advance_token()->is_op(OPERATOR_LCURLY
))
5311 go_error_at(semi_loc
, "missing %<{%> after for clause");
5312 // Otherwise we will get an error when we call this->block
5316 // Build the For_statement and note that it is the current target
5317 // for break and continue statements.
5319 For_statement
* sfor
;
5320 For_range_statement
* srange
;
5322 if (!range_clause
.found
)
5324 sfor
= Statement::make_for_statement(init
, cond
, post
, location
);
5330 srange
= Statement::make_for_range_statement(range_clause
.index
,
5338 this->push_break_statement(s
, label
);
5339 this->push_continue_statement(s
, label
);
5341 // Gather the block of statements in the loop and add them to the
5344 this->gogo_
->start_block(this->location());
5345 Location end_loc
= this->block();
5346 Block
* statements
= this->gogo_
->finish_block(end_loc
);
5349 sfor
->add_statements(statements
);
5351 srange
->add_statements(statements
);
5353 // This is no longer the break/continue target.
5354 this->pop_break_statement();
5355 this->pop_continue_statement();
5357 // Add the For_statement to the list of statements, and close out
5358 // the block we started to hold any variables defined in the for
5361 this->gogo_
->add_statement(s
);
5363 this->gogo_
->add_block(this->gogo_
->finish_block(this->location()),
5367 // ForClause = [ InitStat ] ";" [ Condition ] ";" [ PostStat ] .
5368 // InitStat = SimpleStat .
5369 // PostStat = SimpleStat .
5371 // We have already read InitStat at this point.
5374 Parse::for_clause(Expression
** cond
, Block
** post
)
5376 go_assert(this->peek_token()->is_op(OPERATOR_SEMICOLON
));
5377 this->advance_token();
5378 if (this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5380 else if (this->peek_token()->is_op(OPERATOR_LCURLY
))
5382 go_error_at(this->location(), "missing %<{%> after for clause");
5388 *cond
= this->expression(PRECEDENCE_NORMAL
, false, true, NULL
, NULL
);
5389 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5390 go_error_at(this->location(), "expected semicolon");
5392 this->advance_token();
5394 if (this->peek_token()->is_op(OPERATOR_LCURLY
))
5398 this->gogo_
->start_block(this->location());
5399 this->simple_stat(false, NULL
, NULL
, NULL
);
5400 *post
= this->gogo_
->finish_block(this->location());
5404 // RangeClause = [ IdentifierList ( "=" | ":=" ) ] "range" Expression .
5406 // This is the := version. It is called with a list of identifiers.
5409 Parse::range_clause_decl(const Typed_identifier_list
* til
,
5410 Range_clause
* p_range_clause
)
5412 go_assert(this->peek_token()->is_keyword(KEYWORD_RANGE
));
5413 Location location
= this->location();
5415 p_range_clause
->found
= true;
5417 if (til
->size() > 2)
5418 go_error_at(this->location(), "too many variables for range clause");
5420 this->advance_token();
5421 Expression
* expr
= this->expression(PRECEDENCE_NORMAL
, false, false, NULL
,
5423 p_range_clause
->range
= expr
;
5428 bool any_new
= false;
5430 const Typed_identifier
* pti
= &til
->front();
5431 Named_object
* no
= this->init_var(*pti
, NULL
, expr
, true, true, &any_new
,
5433 if (any_new
&& no
->is_variable())
5434 no
->var_value()->set_type_from_range_index();
5435 p_range_clause
->index
= Expression::make_var_reference(no
, location
);
5437 if (til
->size() == 1)
5438 p_range_clause
->value
= NULL
;
5442 bool is_new
= false;
5443 no
= this->init_var(*pti
, NULL
, expr
, true, true, &is_new
, NULL
, NULL
);
5444 if (is_new
&& no
->is_variable())
5445 no
->var_value()->set_type_from_range_value();
5448 if (!Gogo::is_sink_name(pti
->name()))
5449 p_range_clause
->value
= Expression::make_var_reference(no
, location
);
5453 go_error_at(location
, "variables redeclared but no variable is new");
5456 // The = version of RangeClause. This is called with a list of
5460 Parse::range_clause_expr(const Expression_list
* vals
,
5461 Range_clause
* p_range_clause
)
5463 go_assert(this->peek_token()->is_keyword(KEYWORD_RANGE
));
5465 p_range_clause
->found
= true;
5467 go_assert(vals
->size() >= 1);
5468 if (vals
->size() > 2)
5469 go_error_at(this->location(), "too many variables for range clause");
5471 this->advance_token();
5472 p_range_clause
->range
= this->expression(PRECEDENCE_NORMAL
, false, false,
5478 p_range_clause
->index
= vals
->front();
5479 if (vals
->size() == 1)
5480 p_range_clause
->value
= NULL
;
5482 p_range_clause
->value
= vals
->back();
5485 // Push a statement on the break stack.
5488 Parse::push_break_statement(Statement
* enclosing
, Label
* label
)
5490 if (this->break_stack_
== NULL
)
5491 this->break_stack_
= new Bc_stack();
5492 this->break_stack_
->push_back(std::make_pair(enclosing
, label
));
5495 // Push a statement on the continue stack.
5498 Parse::push_continue_statement(Statement
* enclosing
, Label
* label
)
5500 if (this->continue_stack_
== NULL
)
5501 this->continue_stack_
= new Bc_stack();
5502 this->continue_stack_
->push_back(std::make_pair(enclosing
, label
));
5505 // Pop the break stack.
5508 Parse::pop_break_statement()
5510 this->break_stack_
->pop_back();
5513 // Pop the continue stack.
5516 Parse::pop_continue_statement()
5518 this->continue_stack_
->pop_back();
5521 // Find a break or continue statement given a label name.
5524 Parse::find_bc_statement(const Bc_stack
* bc_stack
, const std::string
& label
)
5526 if (bc_stack
== NULL
)
5528 for (Bc_stack::const_reverse_iterator p
= bc_stack
->rbegin();
5529 p
!= bc_stack
->rend();
5532 if (p
->second
!= NULL
&& p
->second
->name() == label
)
5534 p
->second
->set_is_used();
5541 // BreakStat = "break" [ identifier ] .
5546 go_assert(this->peek_token()->is_keyword(KEYWORD_BREAK
));
5547 Location location
= this->location();
5549 const Token
* token
= this->advance_token();
5550 Statement
* enclosing
;
5551 if (!token
->is_identifier())
5553 if (this->break_stack_
== NULL
|| this->break_stack_
->empty())
5555 go_error_at(this->location(),
5556 "break statement not within for or switch or select");
5559 enclosing
= this->break_stack_
->back().first
;
5563 enclosing
= this->find_bc_statement(this->break_stack_
,
5564 token
->identifier());
5565 if (enclosing
== NULL
)
5567 // If there is a label with this name, mark it as used to
5568 // avoid a useless error about an unused label.
5569 this->gogo_
->add_label_reference(token
->identifier(),
5570 Linemap::unknown_location(), false);
5572 go_error_at(token
->location(), "invalid break label %qs",
5573 Gogo::message_name(token
->identifier()).c_str());
5574 this->advance_token();
5577 this->advance_token();
5580 Unnamed_label
* label
;
5581 if (enclosing
->classification() == Statement::STATEMENT_FOR
)
5582 label
= enclosing
->for_statement()->break_label();
5583 else if (enclosing
->classification() == Statement::STATEMENT_FOR_RANGE
)
5584 label
= enclosing
->for_range_statement()->break_label();
5585 else if (enclosing
->classification() == Statement::STATEMENT_SWITCH
)
5586 label
= enclosing
->switch_statement()->break_label();
5587 else if (enclosing
->classification() == Statement::STATEMENT_TYPE_SWITCH
)
5588 label
= enclosing
->type_switch_statement()->break_label();
5589 else if (enclosing
->classification() == Statement::STATEMENT_SELECT
)
5590 label
= enclosing
->select_statement()->break_label();
5594 this->gogo_
->add_statement(Statement::make_break_statement(label
,
5598 // ContinueStat = "continue" [ identifier ] .
5601 Parse::continue_stat()
5603 go_assert(this->peek_token()->is_keyword(KEYWORD_CONTINUE
));
5604 Location location
= this->location();
5606 const Token
* token
= this->advance_token();
5607 Statement
* enclosing
;
5608 if (!token
->is_identifier())
5610 if (this->continue_stack_
== NULL
|| this->continue_stack_
->empty())
5612 go_error_at(this->location(), "continue statement not within for");
5615 enclosing
= this->continue_stack_
->back().first
;
5619 enclosing
= this->find_bc_statement(this->continue_stack_
,
5620 token
->identifier());
5621 if (enclosing
== NULL
)
5623 // If there is a label with this name, mark it as used to
5624 // avoid a useless error about an unused label.
5625 this->gogo_
->add_label_reference(token
->identifier(),
5626 Linemap::unknown_location(), false);
5628 go_error_at(token
->location(), "invalid continue label %qs",
5629 Gogo::message_name(token
->identifier()).c_str());
5630 this->advance_token();
5633 this->advance_token();
5636 Unnamed_label
* label
;
5637 if (enclosing
->classification() == Statement::STATEMENT_FOR
)
5638 label
= enclosing
->for_statement()->continue_label();
5639 else if (enclosing
->classification() == Statement::STATEMENT_FOR_RANGE
)
5640 label
= enclosing
->for_range_statement()->continue_label();
5644 this->gogo_
->add_statement(Statement::make_continue_statement(label
,
5648 // GotoStat = "goto" identifier .
5653 go_assert(this->peek_token()->is_keyword(KEYWORD_GOTO
));
5654 Location location
= this->location();
5655 const Token
* token
= this->advance_token();
5656 if (!token
->is_identifier())
5657 go_error_at(this->location(), "expected label for goto");
5660 Label
* label
= this->gogo_
->add_label_reference(token
->identifier(),
5662 Statement
* s
= Statement::make_goto_statement(label
, location
);
5663 this->gogo_
->add_statement(s
);
5664 this->advance_token();
5668 // PackageClause = "package" PackageName .
5671 Parse::package_clause()
5673 const Token
* token
= this->peek_token();
5674 Location location
= token
->location();
5676 if (!token
->is_keyword(KEYWORD_PACKAGE
))
5678 go_error_at(this->location(), "program must start with package clause");
5683 token
= this->advance_token();
5684 if (token
->is_identifier())
5686 name
= token
->identifier();
5689 go_error_at(this->location(), "invalid package name _");
5690 name
= Gogo::erroneous_name();
5692 this->advance_token();
5696 go_error_at(this->location(), "package name must be an identifier");
5700 this->gogo_
->set_package_name(name
, location
);
5703 // ImportDecl = "import" Decl<ImportSpec> .
5706 Parse::import_decl()
5708 go_assert(this->peek_token()->is_keyword(KEYWORD_IMPORT
));
5709 this->advance_token();
5710 this->decl(&Parse::import_spec
, NULL
, 0);
5713 // ImportSpec = [ "." | PackageName ] PackageFileName .
5716 Parse::import_spec(void*, unsigned int pragmas
)
5719 go_warning_at(this->location(), 0,
5720 "ignoring magic //go:... comment before import");
5722 const Token
* token
= this->peek_token();
5723 Location location
= token
->location();
5725 std::string local_name
;
5726 bool is_local_name_exported
= false;
5727 if (token
->is_op(OPERATOR_DOT
))
5730 token
= this->advance_token();
5732 else if (token
->is_identifier())
5734 local_name
= token
->identifier();
5735 is_local_name_exported
= token
->is_identifier_exported();
5736 token
= this->advance_token();
5739 if (!token
->is_string())
5741 go_error_at(this->location(), "import statement not a string");
5742 this->advance_token();
5746 this->gogo_
->import_package(token
->string_value(), local_name
,
5747 is_local_name_exported
, true, location
);
5749 this->advance_token();
5752 // SourceFile = PackageClause ";" { ImportDecl ";" }
5753 // { TopLevelDecl ";" } .
5758 this->package_clause();
5760 const Token
* token
= this->peek_token();
5761 if (token
->is_op(OPERATOR_SEMICOLON
))
5762 token
= this->advance_token();
5764 go_error_at(this->location(),
5765 "expected %<;%> or newline after package clause");
5767 while (token
->is_keyword(KEYWORD_IMPORT
))
5769 this->import_decl();
5770 token
= this->peek_token();
5771 if (token
->is_op(OPERATOR_SEMICOLON
))
5772 token
= this->advance_token();
5774 go_error_at(this->location(),
5775 "expected %<;%> or newline after import declaration");
5778 while (!token
->is_eof())
5780 if (this->declaration_may_start_here())
5781 this->declaration();
5784 go_error_at(this->location(), "expected declaration");
5785 this->gogo_
->mark_locals_used();
5787 this->advance_token();
5788 while (!this->peek_token()->is_eof()
5789 && !this->peek_token()->is_op(OPERATOR_SEMICOLON
)
5790 && !this->peek_token()->is_op(OPERATOR_RCURLY
));
5791 if (!this->peek_token()->is_eof()
5792 && !this->peek_token()->is_op(OPERATOR_SEMICOLON
))
5793 this->advance_token();
5795 token
= this->peek_token();
5796 if (token
->is_op(OPERATOR_SEMICOLON
))
5797 token
= this->advance_token();
5798 else if (!token
->is_eof() || !saw_errors())
5800 if (token
->is_op(OPERATOR_CHANOP
))
5801 go_error_at(this->location(),
5802 ("send statement used as value; "
5803 "use select for non-blocking send"));
5805 go_error_at(this->location(),
5806 ("expected %<;%> or newline after top "
5807 "level declaration"));
5808 this->skip_past_error(OPERATOR_INVALID
);
5813 // Reset the current iota value.
5821 // Return the current iota value.
5829 // Increment the current iota value.
5832 Parse::increment_iota()
5837 // Skip forward to a semicolon or OP. OP will normally be
5838 // OPERATOR_RPAREN or OPERATOR_RCURLY. If we find a semicolon, move
5839 // past it and return. If we find OP, it will be the next token to
5840 // read. Return true if we are OK, false if we found EOF.
5843 Parse::skip_past_error(Operator op
)
5845 this->gogo_
->mark_locals_used();
5846 const Token
* token
= this->peek_token();
5847 while (!token
->is_op(op
))
5849 if (token
->is_eof())
5851 if (token
->is_op(OPERATOR_SEMICOLON
))
5853 this->advance_token();
5856 token
= this->advance_token();
5861 // Check that an expression is not a sink.
5864 Parse::verify_not_sink(Expression
* expr
)
5866 if (expr
->is_sink_expression())
5868 go_error_at(expr
->location(), "cannot use _ as value");
5869 expr
= Expression::make_error(expr
->location());
5872 // If this can not be a sink, and it is a variable, then we are
5873 // using the variable, not just assigning to it.
5874 if (expr
->var_expression() != NULL
)
5875 this->mark_var_used(expr
->var_expression()->named_object());
5876 else if (expr
->enclosed_var_expression() != NULL
)
5877 this->mark_var_used(expr
->enclosed_var_expression()->variable());
5881 // Mark a variable as used.
5884 Parse::mark_var_used(Named_object
* no
)
5886 if (no
->is_variable())
5887 no
->var_value()->set_is_used();