1 // parse.cc -- Go frontend parser.
3 // Copyright 2009 The Go Authors. All rights reserved.
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file.
12 #include "statements.h"
13 #include "expressions.h"
16 // Struct Parse::Enclosing_var_comparison.
18 // Return true if v1 should be considered to be less than v2.
21 Parse::Enclosing_var_comparison::operator()(const Enclosing_var& v1,
22 const Enclosing_var& v2)
24 if (v1.var() == v2.var())
27 const std::string& n1(v1.var()->name());
28 const std::string& n2(v2.var()->name());
29 int i = n1.compare(n2);
35 // If we get here it means that a single nested function refers to
36 // two different variables defined in enclosing functions, and both
37 // variables have the same name. I think this is impossible.
43 Parse::Parse(Lex* lex, Gogo* gogo)
45 token_(Token::make_invalid_token(0)),
46 unget_token_(Token::make_invalid_token(0)),
47 unget_token_valid_(false),
50 continue_stack_(NULL),
56 // Return the current token.
61 if (this->unget_token_valid_)
62 return &this->unget_token_;
63 if (this->token_.is_invalid())
64 this->token_ = this->lex_->next_token();
68 // Advance to the next token and return it.
71 Parse::advance_token()
73 if (this->unget_token_valid_)
75 this->unget_token_valid_ = false;
76 if (!this->token_.is_invalid())
79 this->token_ = this->lex_->next_token();
83 // Push a token back on the input stream.
86 Parse::unget_token(const Token& token)
88 go_assert(!this->unget_token_valid_);
89 this->unget_token_ = token;
90 this->unget_token_valid_ = true;
93 // The location of the current token.
98 return this->peek_token()->location();
101 // IdentifierList = identifier { "," identifier } .
104 Parse::identifier_list(Typed_identifier_list* til)
106 const Token* token = this->peek_token();
109 if (!token->is_identifier())
111 error_at(this->location(), "expected identifier");
115 this->gogo_->pack_hidden_name(token->identifier(),
116 token->is_identifier_exported());
117 til->push_back(Typed_identifier(name, NULL, token->location()));
118 token = this->advance_token();
119 if (!token->is_op(OPERATOR_COMMA))
121 token = this->advance_token();
125 // ExpressionList = Expression { "," Expression } .
127 // If MAY_BE_SINK is true, the expressions in the list may be "_".
130 Parse::expression_list(Expression* first, bool may_be_sink)
132 Expression_list* ret = new Expression_list();
134 ret->push_back(first);
137 ret->push_back(this->expression(PRECEDENCE_NORMAL, may_be_sink, true,
140 const Token* token = this->peek_token();
141 if (!token->is_op(OPERATOR_COMMA))
144 // Most expression lists permit a trailing comma.
145 source_location location = token->location();
146 this->advance_token();
147 if (!this->expression_may_start_here())
149 this->unget_token(Token::make_operator_token(OPERATOR_COMMA,
156 // QualifiedIdent = [ PackageName "." ] identifier .
157 // PackageName = identifier .
159 // This sets *PNAME to the identifier and sets *PPACKAGE to the
160 // package or NULL if there isn't one. This returns true on success,
161 // false on failure in which case it will have emitted an error
165 Parse::qualified_ident(std::string* pname, Named_object** ppackage)
167 const Token* token = this->peek_token();
168 if (!token->is_identifier())
170 error_at(this->location(), "expected identifier");
174 std::string name = token->identifier();
175 bool is_exported = token->is_identifier_exported();
176 name = this->gogo_->pack_hidden_name(name, is_exported);
178 token = this->advance_token();
179 if (!token->is_op(OPERATOR_DOT))
186 Named_object* package = this->gogo_->lookup(name, NULL);
187 if (package == NULL || !package->is_package())
189 error_at(this->location(), "expected package");
190 // We expect . IDENTIFIER; skip both.
191 if (this->advance_token()->is_identifier())
192 this->advance_token();
196 package->package_value()->set_used();
198 token = this->advance_token();
199 if (!token->is_identifier())
201 error_at(this->location(), "expected identifier");
205 name = token->identifier();
209 error_at(this->location(), "invalid use of %<_%>");
213 if (package->name() == this->gogo_->package_name())
214 name = this->gogo_->pack_hidden_name(name,
215 token->is_identifier_exported());
220 this->advance_token();
225 // Type = TypeName | TypeLit | "(" Type ")" .
227 // ArrayType | StructType | PointerType | FunctionType | InterfaceType |
228 // SliceType | MapType | ChannelType .
233 const Token* token = this->peek_token();
234 if (token->is_identifier())
235 return this->type_name(true);
236 else if (token->is_op(OPERATOR_LSQUARE))
237 return this->array_type(false);
238 else if (token->is_keyword(KEYWORD_CHAN)
239 || token->is_op(OPERATOR_CHANOP))
240 return this->channel_type();
241 else if (token->is_keyword(KEYWORD_INTERFACE))
242 return this->interface_type();
243 else if (token->is_keyword(KEYWORD_FUNC))
245 source_location location = token->location();
246 this->advance_token();
247 Type* type = this->signature(NULL, location);
249 return Type::make_error_type();
252 else if (token->is_keyword(KEYWORD_MAP))
253 return this->map_type();
254 else if (token->is_keyword(KEYWORD_STRUCT))
255 return this->struct_type();
256 else if (token->is_op(OPERATOR_MULT))
257 return this->pointer_type();
258 else if (token->is_op(OPERATOR_LPAREN))
260 this->advance_token();
261 Type* ret = this->type();
262 if (this->peek_token()->is_op(OPERATOR_RPAREN))
263 this->advance_token();
266 if (!ret->is_error_type())
267 error_at(this->location(), "expected %<)%>");
273 error_at(token->location(), "expected type");
274 return Type::make_error_type();
279 Parse::type_may_start_here()
281 const Token* token = this->peek_token();
282 return (token->is_identifier()
283 || token->is_op(OPERATOR_LSQUARE)
284 || token->is_op(OPERATOR_CHANOP)
285 || token->is_keyword(KEYWORD_CHAN)
286 || token->is_keyword(KEYWORD_INTERFACE)
287 || token->is_keyword(KEYWORD_FUNC)
288 || token->is_keyword(KEYWORD_MAP)
289 || token->is_keyword(KEYWORD_STRUCT)
290 || token->is_op(OPERATOR_MULT)
291 || token->is_op(OPERATOR_LPAREN));
294 // TypeName = QualifiedIdent .
296 // If MAY_BE_NIL is true, then an identifier with the value of the
297 // predefined constant nil is accepted, returning the nil type.
300 Parse::type_name(bool issue_error)
302 source_location location = this->location();
305 Named_object* package;
306 if (!this->qualified_ident(&name, &package))
307 return Type::make_error_type();
309 Named_object* named_object;
311 named_object = this->gogo_->lookup(name, NULL);
314 named_object = package->package_value()->lookup(name);
315 if (named_object == NULL
317 && package->name() != this->gogo_->package_name())
319 // Check whether the name is there but hidden.
320 std::string s = ('.' + package->package_value()->unique_prefix()
321 + '.' + package->package_value()->name()
323 named_object = package->package_value()->lookup(s);
324 if (named_object != NULL)
326 const std::string& packname(package->package_value()->name());
327 error_at(location, "invalid reference to hidden type %<%s.%s%>",
328 Gogo::message_name(packname).c_str(),
329 Gogo::message_name(name).c_str());
336 if (named_object == NULL)
339 named_object = this->gogo_->add_unknown_name(name, location);
342 const std::string& packname(package->package_value()->name());
343 error_at(location, "reference to undefined identifier %<%s.%s%>",
344 Gogo::message_name(packname).c_str(),
345 Gogo::message_name(name).c_str());
350 else if (named_object->is_type())
352 if (!named_object->type_value()->is_visible())
355 else if (named_object->is_unknown() || named_object->is_type_declaration())
363 error_at(location, "expected type");
364 return Type::make_error_type();
367 if (named_object->is_type())
368 return named_object->type_value();
369 else if (named_object->is_unknown() || named_object->is_type_declaration())
370 return Type::make_forward_declaration(named_object);
375 // ArrayType = "[" [ ArrayLength ] "]" ElementType .
376 // ArrayLength = Expression .
377 // ElementType = CompleteType .
380 Parse::array_type(bool may_use_ellipsis)
382 go_assert(this->peek_token()->is_op(OPERATOR_LSQUARE));
383 const Token* token = this->advance_token();
385 Expression* length = NULL;
386 if (token->is_op(OPERATOR_RSQUARE))
387 this->advance_token();
390 if (!token->is_op(OPERATOR_ELLIPSIS))
391 length = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
392 else if (may_use_ellipsis)
394 // An ellipsis is used in composite literals to represent a
395 // fixed array of the size of the number of elements. We
396 // use a length of nil to represent this, and change the
397 // length when parsing the composite literal.
398 length = Expression::make_nil(this->location());
399 this->advance_token();
403 error_at(this->location(),
404 "use of %<[...]%> outside of array literal");
405 length = Expression::make_error(this->location());
406 this->advance_token();
408 if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
410 error_at(this->location(), "expected %<]%>");
411 return Type::make_error_type();
413 this->advance_token();
416 Type* element_type = this->type();
418 return Type::make_array_type(element_type, length);
421 // MapType = "map" "[" KeyType "]" ValueType .
422 // KeyType = CompleteType .
423 // ValueType = CompleteType .
428 source_location location = this->location();
429 go_assert(this->peek_token()->is_keyword(KEYWORD_MAP));
430 if (!this->advance_token()->is_op(OPERATOR_LSQUARE))
432 error_at(this->location(), "expected %<[%>");
433 return Type::make_error_type();
435 this->advance_token();
437 Type* key_type = this->type();
439 if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
441 error_at(this->location(), "expected %<]%>");
442 return Type::make_error_type();
444 this->advance_token();
446 Type* value_type = this->type();
448 if (key_type->is_error_type() || value_type->is_error_type())
449 return Type::make_error_type();
451 return Type::make_map_type(key_type, value_type, location);
454 // StructType = "struct" "{" { FieldDecl ";" } "}" .
459 go_assert(this->peek_token()->is_keyword(KEYWORD_STRUCT));
460 source_location location = this->location();
461 if (!this->advance_token()->is_op(OPERATOR_LCURLY))
463 source_location token_loc = this->location();
464 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
465 && this->advance_token()->is_op(OPERATOR_LCURLY))
466 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
469 error_at(this->location(), "expected %<{%>");
470 return Type::make_error_type();
473 this->advance_token();
475 Struct_field_list* sfl = new Struct_field_list;
476 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
478 this->field_decl(sfl);
479 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
480 this->advance_token();
481 else if (!this->peek_token()->is_op(OPERATOR_RCURLY))
483 error_at(this->location(), "expected %<;%> or %<}%> or newline");
484 if (!this->skip_past_error(OPERATOR_RCURLY))
485 return Type::make_error_type();
488 this->advance_token();
490 for (Struct_field_list::const_iterator pi = sfl->begin();
494 if (pi->type()->is_error_type())
496 for (Struct_field_list::const_iterator pj = pi + 1;
500 if (pi->field_name() == pj->field_name()
501 && !Gogo::is_sink_name(pi->field_name()))
502 error_at(pi->location(), "duplicate field name %<%s%>",
503 Gogo::message_name(pi->field_name()).c_str());
507 return Type::make_struct_type(sfl, location);
510 // FieldDecl = (IdentifierList CompleteType | TypeName) [ Tag ] .
511 // Tag = string_lit .
514 Parse::field_decl(Struct_field_list* sfl)
516 const Token* token = this->peek_token();
517 source_location location = token->location();
519 bool is_anonymous_pointer;
520 if (token->is_op(OPERATOR_MULT))
523 is_anonymous_pointer = true;
525 else if (token->is_identifier())
527 std::string id = token->identifier();
528 bool is_id_exported = token->is_identifier_exported();
529 source_location id_location = token->location();
530 token = this->advance_token();
531 is_anonymous = (token->is_op(OPERATOR_SEMICOLON)
532 || token->is_op(OPERATOR_RCURLY)
533 || token->is_op(OPERATOR_DOT)
534 || token->is_string());
535 is_anonymous_pointer = false;
536 this->unget_token(Token::make_identifier_token(id, is_id_exported,
541 error_at(this->location(), "expected field name");
542 while (!token->is_op(OPERATOR_SEMICOLON)
543 && !token->is_op(OPERATOR_RCURLY)
545 token = this->advance_token();
551 if (is_anonymous_pointer)
553 this->advance_token();
554 if (!this->peek_token()->is_identifier())
556 error_at(this->location(), "expected field name");
557 while (!token->is_op(OPERATOR_SEMICOLON)
558 && !token->is_op(OPERATOR_RCURLY)
560 token = this->advance_token();
564 Type* type = this->type_name(true);
567 if (this->peek_token()->is_string())
569 tag = this->peek_token()->string_value();
570 this->advance_token();
573 if (!type->is_error_type())
575 if (is_anonymous_pointer)
576 type = Type::make_pointer_type(type);
577 sfl->push_back(Struct_field(Typed_identifier("", type, location)));
579 sfl->back().set_tag(tag);
584 Typed_identifier_list til;
587 token = this->peek_token();
588 if (!token->is_identifier())
590 error_at(this->location(), "expected identifier");
594 this->gogo_->pack_hidden_name(token->identifier(),
595 token->is_identifier_exported());
596 til.push_back(Typed_identifier(name, NULL, token->location()));
597 if (!this->advance_token()->is_op(OPERATOR_COMMA))
599 this->advance_token();
602 Type* type = this->type();
605 if (this->peek_token()->is_string())
607 tag = this->peek_token()->string_value();
608 this->advance_token();
611 for (Typed_identifier_list::iterator p = til.begin();
616 sfl->push_back(Struct_field(*p));
618 sfl->back().set_tag(tag);
623 // PointerType = "*" Type .
626 Parse::pointer_type()
628 go_assert(this->peek_token()->is_op(OPERATOR_MULT));
629 this->advance_token();
630 Type* type = this->type();
631 if (type->is_error_type())
633 return Type::make_pointer_type(type);
636 // ChannelType = Channel | SendChannel | RecvChannel .
637 // Channel = "chan" ElementType .
638 // SendChannel = "chan" "<-" ElementType .
639 // RecvChannel = "<-" "chan" ElementType .
642 Parse::channel_type()
644 const Token* token = this->peek_token();
647 if (token->is_op(OPERATOR_CHANOP))
649 if (!this->advance_token()->is_keyword(KEYWORD_CHAN))
651 error_at(this->location(), "expected %<chan%>");
652 return Type::make_error_type();
655 this->advance_token();
659 go_assert(token->is_keyword(KEYWORD_CHAN));
660 if (this->advance_token()->is_op(OPERATOR_CHANOP))
663 this->advance_token();
667 // Better error messages for the common error of omitting the
668 // channel element type.
669 if (!this->type_may_start_here())
671 token = this->peek_token();
672 if (token->is_op(OPERATOR_RCURLY))
673 error_at(this->location(), "unexpected %<}%> in channel type");
674 else if (token->is_op(OPERATOR_RPAREN))
675 error_at(this->location(), "unexpected %<)%> in channel type");
676 else if (token->is_op(OPERATOR_COMMA))
677 error_at(this->location(), "unexpected comma in channel type");
679 error_at(this->location(), "expected channel element type");
680 return Type::make_error_type();
683 Type* element_type = this->type();
684 return Type::make_channel_type(send, receive, element_type);
687 // Give an error for a duplicate parameter or receiver name.
690 Parse::check_signature_names(const Typed_identifier_list* params,
693 for (Typed_identifier_list::const_iterator p = params->begin();
697 if (p->name().empty() || Gogo::is_sink_name(p->name()))
699 std::pair<std::string, const Typed_identifier*> val =
700 std::make_pair(p->name(), &*p);
701 std::pair<Parse::Names::iterator, bool> ins = names->insert(val);
704 error_at(p->location(), "redefinition of %qs",
705 Gogo::message_name(p->name()).c_str());
706 inform(ins.first->second->location(),
707 "previous definition of %qs was here",
708 Gogo::message_name(p->name()).c_str());
713 // Signature = Parameters [ Result ] .
715 // RECEIVER is the receiver if there is one, or NULL. LOCATION is the
716 // location of the start of the type.
718 // This returns NULL on a parse error.
721 Parse::signature(Typed_identifier* receiver, source_location location)
723 bool is_varargs = false;
724 Typed_identifier_list* params;
725 bool params_ok = this->parameters(¶ms, &is_varargs);
727 Typed_identifier_list* results = NULL;
728 if (this->peek_token()->is_op(OPERATOR_LPAREN)
729 || this->type_may_start_here())
731 if (!this->result(&results))
740 this->check_signature_names(params, &names);
742 this->check_signature_names(results, &names);
744 Function_type* ret = Type::make_function_type(receiver, params, results,
747 ret->set_is_varargs();
751 // Parameters = "(" [ ParameterList [ "," ] ] ")" .
753 // This returns false on a parse error.
756 Parse::parameters(Typed_identifier_list** pparams, bool* is_varargs)
760 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
762 error_at(this->location(), "expected %<(%>");
766 Typed_identifier_list* params = NULL;
767 bool saw_error = false;
769 const Token* token = this->advance_token();
770 if (!token->is_op(OPERATOR_RPAREN))
772 params = this->parameter_list(is_varargs);
775 token = this->peek_token();
778 // The optional trailing comma is picked up in parameter_list.
780 if (!token->is_op(OPERATOR_RPAREN))
781 error_at(this->location(), "expected %<)%>");
783 this->advance_token();
792 // ParameterList = ParameterDecl { "," ParameterDecl } .
794 // This sets *IS_VARARGS if the list ends with an ellipsis.
795 // IS_VARARGS will be NULL if varargs are not permitted.
797 // We pick up an optional trailing comma.
799 // This returns NULL if some error is seen.
801 Typed_identifier_list*
802 Parse::parameter_list(bool* is_varargs)
804 source_location location = this->location();
805 Typed_identifier_list* ret = new Typed_identifier_list();
807 bool saw_error = false;
809 // If we see an identifier and then a comma, then we don't know
810 // whether we are looking at a list of identifiers followed by a
811 // type, or a list of types given by name. We have to do an
812 // arbitrary lookahead to figure it out.
814 bool parameters_have_names;
815 const Token* token = this->peek_token();
816 if (!token->is_identifier())
818 // This must be a type which starts with something like '*'.
819 parameters_have_names = false;
823 std::string name = token->identifier();
824 bool is_exported = token->is_identifier_exported();
825 source_location location = token->location();
826 token = this->advance_token();
827 if (!token->is_op(OPERATOR_COMMA))
829 if (token->is_op(OPERATOR_DOT))
831 // This is a qualified identifier, which must turn out
833 parameters_have_names = false;
835 else if (token->is_op(OPERATOR_RPAREN))
837 // A single identifier followed by a parenthesis must be
839 parameters_have_names = false;
843 // An identifier followed by something other than a
844 // comma or a dot or a right parenthesis must be a
845 // parameter name followed by a type.
846 parameters_have_names = true;
849 this->unget_token(Token::make_identifier_token(name, is_exported,
854 // An identifier followed by a comma may be the first in a
855 // list of parameter names followed by a type, or it may be
856 // the first in a list of types without parameter names. To
857 // find out we gather as many identifiers separated by
859 std::string id_name = this->gogo_->pack_hidden_name(name,
861 ret->push_back(Typed_identifier(id_name, NULL, location));
862 bool just_saw_comma = true;
863 while (this->advance_token()->is_identifier())
865 name = this->peek_token()->identifier();
866 is_exported = this->peek_token()->is_identifier_exported();
867 location = this->peek_token()->location();
868 id_name = this->gogo_->pack_hidden_name(name, is_exported);
869 ret->push_back(Typed_identifier(id_name, NULL, location));
870 if (!this->advance_token()->is_op(OPERATOR_COMMA))
872 just_saw_comma = false;
879 // We saw ID1 "," ID2 "," followed by something which
880 // was not an identifier. We must be seeing the start
881 // of a type, and ID1 and ID2 must be types, and the
882 // parameters don't have names.
883 parameters_have_names = false;
885 else if (this->peek_token()->is_op(OPERATOR_RPAREN))
887 // We saw ID1 "," ID2 ")". ID1 and ID2 must be types,
888 // and the parameters don't have names.
889 parameters_have_names = false;
891 else if (this->peek_token()->is_op(OPERATOR_DOT))
893 // We saw ID1 "," ID2 ".". ID2 must be a package name,
894 // ID1 must be a type, and the parameters don't have
896 parameters_have_names = false;
897 this->unget_token(Token::make_identifier_token(name, is_exported,
900 just_saw_comma = true;
904 // We saw ID1 "," ID2 followed by something other than
905 // ",", ".", or ")". We must be looking at the start of
906 // a type, and ID1 and ID2 must be parameter names.
907 parameters_have_names = true;
910 if (parameters_have_names)
912 go_assert(!just_saw_comma);
913 // We have just seen ID1, ID2 xxx.
915 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
919 error_at(this->location(), "%<...%> only permits one name");
921 this->advance_token();
924 for (size_t i = 0; i < ret->size(); ++i)
925 ret->set_type(i, type);
926 if (!this->peek_token()->is_op(OPERATOR_COMMA))
927 return saw_error ? NULL : ret;
928 if (this->advance_token()->is_op(OPERATOR_RPAREN))
929 return saw_error ? NULL : ret;
933 Typed_identifier_list* tret = new Typed_identifier_list();
934 for (Typed_identifier_list::const_iterator p = ret->begin();
938 Named_object* no = this->gogo_->lookup(p->name(), NULL);
941 no = this->gogo_->add_unknown_name(p->name(),
945 type = no->type_value();
946 else if (no->is_unknown() || no->is_type_declaration())
947 type = Type::make_forward_declaration(no);
950 error_at(p->location(), "expected %<%s%> to be a type",
951 Gogo::message_name(p->name()).c_str());
953 type = Type::make_error_type();
955 tret->push_back(Typed_identifier("", type, p->location()));
960 || this->peek_token()->is_op(OPERATOR_RPAREN))
961 return saw_error ? NULL : ret;
966 bool mix_error = false;
967 this->parameter_decl(parameters_have_names, ret, is_varargs, &mix_error);
968 while (this->peek_token()->is_op(OPERATOR_COMMA))
970 if (is_varargs != NULL && *is_varargs)
972 error_at(this->location(), "%<...%> must be last parameter");
975 if (this->advance_token()->is_op(OPERATOR_RPAREN))
977 this->parameter_decl(parameters_have_names, ret, is_varargs, &mix_error);
981 error_at(location, "invalid named/anonymous mix");
992 // ParameterDecl = [ IdentifierList ] [ "..." ] Type .
995 Parse::parameter_decl(bool parameters_have_names,
996 Typed_identifier_list* til,
1000 if (!parameters_have_names)
1003 source_location location = this->location();
1004 if (!this->peek_token()->is_identifier())
1006 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
1007 type = this->type();
1010 if (is_varargs == NULL)
1011 error_at(this->location(), "invalid use of %<...%>");
1014 this->advance_token();
1015 if (is_varargs == NULL
1016 && this->peek_token()->is_op(OPERATOR_RPAREN))
1017 type = Type::make_error_type();
1020 Type* element_type = this->type();
1021 type = Type::make_array_type(element_type, NULL);
1027 type = this->type_name(false);
1028 if (type->is_error_type()
1029 || (!this->peek_token()->is_op(OPERATOR_COMMA)
1030 && !this->peek_token()->is_op(OPERATOR_RPAREN)))
1033 while (!this->peek_token()->is_op(OPERATOR_COMMA)
1034 && !this->peek_token()->is_op(OPERATOR_RPAREN))
1035 this->advance_token();
1038 if (!type->is_error_type())
1039 til->push_back(Typed_identifier("", type, location));
1043 size_t orig_count = til->size();
1044 if (this->peek_token()->is_identifier())
1045 this->identifier_list(til);
1048 size_t new_count = til->size();
1051 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
1052 type = this->type();
1055 if (is_varargs == NULL)
1056 error_at(this->location(), "invalid use of %<...%>");
1057 else if (new_count > orig_count + 1)
1058 error_at(this->location(), "%<...%> only permits one name");
1061 this->advance_token();
1062 Type* element_type = this->type();
1063 type = Type::make_array_type(element_type, NULL);
1065 for (size_t i = orig_count; i < new_count; ++i)
1066 til->set_type(i, type);
1070 // Result = Parameters | Type .
1072 // This returns false on a parse error.
1075 Parse::result(Typed_identifier_list** presults)
1077 if (this->peek_token()->is_op(OPERATOR_LPAREN))
1078 return this->parameters(presults, NULL);
1081 source_location location = this->location();
1082 Type* type = this->type();
1083 if (type->is_error_type())
1088 Typed_identifier_list* til = new Typed_identifier_list();
1089 til->push_back(Typed_identifier("", type, location));
1095 // Block = "{" [ StatementList ] "}" .
1097 // Returns the location of the closing brace.
1102 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
1104 source_location loc = this->location();
1105 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1106 && this->advance_token()->is_op(OPERATOR_LCURLY))
1107 error_at(loc, "unexpected semicolon or newline before %<{%>");
1110 error_at(this->location(), "expected %<{%>");
1111 return UNKNOWN_LOCATION;
1115 const Token* token = this->advance_token();
1117 if (!token->is_op(OPERATOR_RCURLY))
1119 this->statement_list();
1120 token = this->peek_token();
1121 if (!token->is_op(OPERATOR_RCURLY))
1123 if (!token->is_eof() || !saw_errors())
1124 error_at(this->location(), "expected %<}%>");
1126 // Skip ahead to the end of the block, in hopes of avoiding
1127 // lots of meaningless errors.
1128 source_location ret = token->location();
1130 while (!token->is_eof())
1132 if (token->is_op(OPERATOR_LCURLY))
1134 else if (token->is_op(OPERATOR_RCURLY))
1139 this->advance_token();
1143 token = this->advance_token();
1144 ret = token->location();
1150 source_location ret = token->location();
1151 this->advance_token();
1155 // InterfaceType = "interface" "{" [ MethodSpecList ] "}" .
1156 // MethodSpecList = MethodSpec { ";" MethodSpec } [ ";" ] .
1159 Parse::interface_type()
1161 go_assert(this->peek_token()->is_keyword(KEYWORD_INTERFACE));
1162 source_location location = this->location();
1164 if (!this->advance_token()->is_op(OPERATOR_LCURLY))
1166 source_location token_loc = this->location();
1167 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1168 && this->advance_token()->is_op(OPERATOR_LCURLY))
1169 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
1172 error_at(this->location(), "expected %<{%>");
1173 return Type::make_error_type();
1176 this->advance_token();
1178 Typed_identifier_list* methods = new Typed_identifier_list();
1179 if (!this->peek_token()->is_op(OPERATOR_RCURLY))
1181 this->method_spec(methods);
1182 while (this->peek_token()->is_op(OPERATOR_SEMICOLON))
1184 if (this->advance_token()->is_op(OPERATOR_RCURLY))
1186 this->method_spec(methods);
1188 if (!this->peek_token()->is_op(OPERATOR_RCURLY))
1190 error_at(this->location(), "expected %<}%>");
1191 while (!this->advance_token()->is_op(OPERATOR_RCURLY))
1193 if (this->peek_token()->is_eof())
1194 return Type::make_error_type();
1198 this->advance_token();
1200 if (methods->empty())
1206 Interface_type* ret = Type::make_interface_type(methods, location);
1207 this->gogo_->record_interface_type(ret);
1211 // MethodSpec = MethodName Signature | InterfaceTypeName .
1212 // MethodName = identifier .
1213 // InterfaceTypeName = TypeName .
1216 Parse::method_spec(Typed_identifier_list* methods)
1218 const Token* token = this->peek_token();
1219 if (!token->is_identifier())
1221 error_at(this->location(), "expected identifier");
1225 std::string name = token->identifier();
1226 bool is_exported = token->is_identifier_exported();
1227 source_location location = token->location();
1229 if (this->advance_token()->is_op(OPERATOR_LPAREN))
1231 // This is a MethodName.
1232 name = this->gogo_->pack_hidden_name(name, is_exported);
1233 Type* type = this->signature(NULL, location);
1236 methods->push_back(Typed_identifier(name, type, location));
1240 this->unget_token(Token::make_identifier_token(name, is_exported,
1242 Type* type = this->type_name(false);
1243 if (type->is_error_type()
1244 || (!this->peek_token()->is_op(OPERATOR_SEMICOLON)
1245 && !this->peek_token()->is_op(OPERATOR_RCURLY)))
1247 if (this->peek_token()->is_op(OPERATOR_COMMA))
1248 error_at(this->location(),
1249 "name list not allowed in interface type");
1251 error_at(location, "expected signature or type name");
1252 token = this->peek_token();
1253 while (!token->is_eof()
1254 && !token->is_op(OPERATOR_SEMICOLON)
1255 && !token->is_op(OPERATOR_RCURLY))
1256 token = this->advance_token();
1259 // This must be an interface type, but we can't check that now.
1260 // We check it and pull out the methods in
1261 // Interface_type::do_verify.
1262 methods->push_back(Typed_identifier("", type, location));
1266 // Declaration = ConstDecl | TypeDecl | VarDecl | FunctionDecl | MethodDecl .
1269 Parse::declaration()
1271 const Token* token = this->peek_token();
1272 if (token->is_keyword(KEYWORD_CONST))
1274 else if (token->is_keyword(KEYWORD_TYPE))
1276 else if (token->is_keyword(KEYWORD_VAR))
1278 else if (token->is_keyword(KEYWORD_FUNC))
1279 this->function_decl();
1282 error_at(this->location(), "expected declaration");
1283 this->advance_token();
1288 Parse::declaration_may_start_here()
1290 const Token* token = this->peek_token();
1291 return (token->is_keyword(KEYWORD_CONST)
1292 || token->is_keyword(KEYWORD_TYPE)
1293 || token->is_keyword(KEYWORD_VAR)
1294 || token->is_keyword(KEYWORD_FUNC));
1297 // Decl<P> = P | "(" [ List<P> ] ")" .
1300 Parse::decl(void (Parse::*pfn)(void*), void* varg)
1302 if (this->peek_token()->is_eof())
1305 error_at(this->location(), "unexpected end of file");
1309 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
1313 if (!this->advance_token()->is_op(OPERATOR_RPAREN))
1315 this->list(pfn, varg, true);
1316 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
1318 error_at(this->location(), "missing %<)%>");
1319 while (!this->advance_token()->is_op(OPERATOR_RPAREN))
1321 if (this->peek_token()->is_eof())
1326 this->advance_token();
1330 // List<P> = P { ";" P } [ ";" ] .
1332 // In order to pick up the trailing semicolon we need to know what
1333 // might follow. This is either a '}' or a ')'.
1336 Parse::list(void (Parse::*pfn)(void*), void* varg, bool follow_is_paren)
1339 Operator follow = follow_is_paren ? OPERATOR_RPAREN : OPERATOR_RCURLY;
1340 while (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1341 || this->peek_token()->is_op(OPERATOR_COMMA))
1343 if (this->peek_token()->is_op(OPERATOR_COMMA))
1344 error_at(this->location(), "unexpected comma");
1345 if (this->advance_token()->is_op(follow))
1351 // ConstDecl = "const" ( ConstSpec | "(" { ConstSpec ";" } ")" ) .
1356 go_assert(this->peek_token()->is_keyword(KEYWORD_CONST));
1357 this->advance_token();
1360 Type* last_type = NULL;
1361 Expression_list* last_expr_list = NULL;
1363 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
1364 this->const_spec(&last_type, &last_expr_list);
1367 this->advance_token();
1368 while (!this->peek_token()->is_op(OPERATOR_RPAREN))
1370 this->const_spec(&last_type, &last_expr_list);
1371 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
1372 this->advance_token();
1373 else if (!this->peek_token()->is_op(OPERATOR_RPAREN))
1375 error_at(this->location(), "expected %<;%> or %<)%> or newline");
1376 if (!this->skip_past_error(OPERATOR_RPAREN))
1380 this->advance_token();
1383 if (last_expr_list != NULL)
1384 delete last_expr_list;
1387 // ConstSpec = IdentifierList [ [ CompleteType ] "=" ExpressionList ] .
1390 Parse::const_spec(Type** last_type, Expression_list** last_expr_list)
1392 Typed_identifier_list til;
1393 this->identifier_list(&til);
1396 if (this->type_may_start_here())
1398 type = this->type();
1400 *last_expr_list = NULL;
1403 Expression_list *expr_list;
1404 if (!this->peek_token()->is_op(OPERATOR_EQ))
1406 if (*last_expr_list == NULL)
1408 error_at(this->location(), "expected %<=%>");
1412 expr_list = new Expression_list;
1413 for (Expression_list::const_iterator p = (*last_expr_list)->begin();
1414 p != (*last_expr_list)->end();
1416 expr_list->push_back((*p)->copy());
1420 this->advance_token();
1421 expr_list = this->expression_list(NULL, false);
1423 if (*last_expr_list != NULL)
1424 delete *last_expr_list;
1425 *last_expr_list = expr_list;
1428 Expression_list::const_iterator pe = expr_list->begin();
1429 for (Typed_identifier_list::iterator pi = til.begin();
1433 if (pe == expr_list->end())
1435 error_at(this->location(), "not enough initializers");
1441 if (!Gogo::is_sink_name(pi->name()))
1442 this->gogo_->add_constant(*pi, *pe, this->iota_value());
1444 if (pe != expr_list->end())
1445 error_at(this->location(), "too many initializers");
1447 this->increment_iota();
1452 // TypeDecl = "type" Decl<TypeSpec> .
1457 go_assert(this->peek_token()->is_keyword(KEYWORD_TYPE));
1458 this->advance_token();
1459 this->decl(&Parse::type_spec, NULL);
1462 // TypeSpec = identifier Type .
1465 Parse::type_spec(void*)
1467 const Token* token = this->peek_token();
1468 if (!token->is_identifier())
1470 error_at(this->location(), "expected identifier");
1473 std::string name = token->identifier();
1474 bool is_exported = token->is_identifier_exported();
1475 source_location location = token->location();
1476 token = this->advance_token();
1478 // The scope of the type name starts at the point where the
1479 // identifier appears in the source code. We implement this by
1480 // declaring the type before we read the type definition.
1481 Named_object* named_type = NULL;
1484 name = this->gogo_->pack_hidden_name(name, is_exported);
1485 named_type = this->gogo_->declare_type(name, location);
1489 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
1490 type = this->type();
1493 error_at(this->location(),
1494 "unexpected semicolon or newline in type declaration");
1495 type = Type::make_error_type();
1496 this->advance_token();
1499 if (type->is_error_type())
1501 while (!this->peek_token()->is_op(OPERATOR_SEMICOLON)
1502 && !this->peek_token()->is_eof())
1503 this->advance_token();
1508 if (named_type->is_type_declaration())
1510 Type* ftype = type->forwarded();
1511 if (ftype->forward_declaration_type() != NULL
1512 && (ftype->forward_declaration_type()->named_object()
1515 error_at(location, "invalid recursive type");
1516 type = Type::make_error_type();
1519 this->gogo_->define_type(named_type,
1520 Type::make_named_type(named_type, type,
1522 go_assert(named_type->package() == NULL);
1526 // This will probably give a redefinition error.
1527 this->gogo_->add_type(name, type, location);
1532 // VarDecl = "var" Decl<VarSpec> .
1537 go_assert(this->peek_token()->is_keyword(KEYWORD_VAR));
1538 this->advance_token();
1539 this->decl(&Parse::var_spec, NULL);
1542 // VarSpec = IdentifierList
1543 // ( CompleteType [ "=" ExpressionList ] | "=" ExpressionList ) .
1546 Parse::var_spec(void*)
1548 // Get the variable names.
1549 Typed_identifier_list til;
1550 this->identifier_list(&til);
1552 source_location location = this->location();
1555 Expression_list* init = NULL;
1556 if (!this->peek_token()->is_op(OPERATOR_EQ))
1558 type = this->type();
1559 if (type->is_error_type())
1561 while (!this->peek_token()->is_op(OPERATOR_EQ)
1562 && !this->peek_token()->is_op(OPERATOR_SEMICOLON)
1563 && !this->peek_token()->is_eof())
1564 this->advance_token();
1566 if (this->peek_token()->is_op(OPERATOR_EQ))
1568 this->advance_token();
1569 init = this->expression_list(NULL, false);
1574 this->advance_token();
1575 init = this->expression_list(NULL, false);
1578 this->init_vars(&til, type, init, false, location);
1584 // Create variables. TIL is a list of variable names. If TYPE is not
1585 // NULL, it is the type of all the variables. If INIT is not NULL, it
1586 // is an initializer list for the variables.
1589 Parse::init_vars(const Typed_identifier_list* til, Type* type,
1590 Expression_list* init, bool is_coloneq,
1591 source_location location)
1593 // Check for an initialization which can yield multiple values.
1594 if (init != NULL && init->size() == 1 && til->size() > 1)
1596 if (this->init_vars_from_call(til, type, *init->begin(), is_coloneq,
1599 if (this->init_vars_from_map(til, type, *init->begin(), is_coloneq,
1602 if (this->init_vars_from_receive(til, type, *init->begin(), is_coloneq,
1605 if (this->init_vars_from_type_guard(til, type, *init->begin(),
1606 is_coloneq, location))
1610 if (init != NULL && init->size() != til->size())
1612 if (init->empty() || !init->front()->is_error_expression())
1613 error_at(location, "wrong number of initializations");
1616 type = Type::make_error_type();
1619 // Note that INIT was already parsed with the old name bindings, so
1620 // we don't have to worry that it will accidentally refer to the
1621 // newly declared variables.
1623 Expression_list::const_iterator pexpr;
1625 pexpr = init->begin();
1626 bool any_new = false;
1627 for (Typed_identifier_list::const_iterator p = til->begin();
1632 go_assert(pexpr != init->end());
1633 this->init_var(*p, type, init == NULL ? NULL : *pexpr, is_coloneq,
1639 go_assert(pexpr == init->end());
1640 if (is_coloneq && !any_new)
1641 error_at(location, "variables redeclared but no variable is new");
1644 // See if we need to initialize a list of variables from a function
1645 // call. This returns true if we have set up the variables and the
1649 Parse::init_vars_from_call(const Typed_identifier_list* vars, Type* type,
1650 Expression* expr, bool is_coloneq,
1651 source_location location)
1653 Call_expression* call = expr->call_expression();
1657 // This is a function call. We can't check here whether it returns
1658 // the right number of values, but it might. Declare the variables,
1659 // and then assign the results of the call to them.
1661 unsigned int index = 0;
1662 bool any_new = false;
1663 for (Typed_identifier_list::const_iterator pv = vars->begin();
1667 Expression* init = Expression::make_call_result(call, index);
1668 this->init_var(*pv, type, init, is_coloneq, false, &any_new);
1671 if (is_coloneq && !any_new)
1672 error_at(location, "variables redeclared but no variable is new");
1677 // See if we need to initialize a pair of values from a map index
1678 // expression. This returns true if we have set up the variables and
1679 // the initialization.
1682 Parse::init_vars_from_map(const Typed_identifier_list* vars, Type* type,
1683 Expression* expr, bool is_coloneq,
1684 source_location location)
1686 Index_expression* index = expr->index_expression();
1689 if (vars->size() != 2)
1692 // This is an index which is being assigned to two variables. It
1693 // must be a map index. Declare the variables, and then assign the
1694 // results of the map index.
1695 bool any_new = false;
1696 Typed_identifier_list::const_iterator p = vars->begin();
1697 Expression* init = type == NULL ? index : NULL;
1698 Named_object* val_no = this->init_var(*p, type, init, is_coloneq,
1699 type == NULL, &any_new);
1700 if (type == NULL && any_new && val_no->is_variable())
1701 val_no->var_value()->set_type_from_init_tuple();
1702 Expression* val_var = Expression::make_var_reference(val_no, location);
1705 Type* var_type = type;
1706 if (var_type == NULL)
1707 var_type = Type::lookup_bool_type();
1708 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1710 Expression* present_var = Expression::make_var_reference(no, location);
1712 if (is_coloneq && !any_new)
1713 error_at(location, "variables redeclared but no variable is new");
1715 Statement* s = Statement::make_tuple_map_assignment(val_var, present_var,
1718 if (!this->gogo_->in_global_scope())
1719 this->gogo_->add_statement(s);
1720 else if (!val_no->is_sink())
1722 if (val_no->is_variable())
1723 val_no->var_value()->add_preinit_statement(this->gogo_, s);
1725 else if (!no->is_sink())
1727 if (no->is_variable())
1728 no->var_value()->add_preinit_statement(this->gogo_, s);
1732 // Execute the map index expression just so that we can fail if
1734 Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
1736 dummy->var_value()->add_preinit_statement(this->gogo_, s);
1742 // See if we need to initialize a pair of values from a receive
1743 // expression. This returns true if we have set up the variables and
1744 // the initialization.
1747 Parse::init_vars_from_receive(const Typed_identifier_list* vars, Type* type,
1748 Expression* expr, bool is_coloneq,
1749 source_location location)
1751 Receive_expression* receive = expr->receive_expression();
1752 if (receive == NULL)
1754 if (vars->size() != 2)
1757 // This is a receive expression which is being assigned to two
1758 // variables. Declare the variables, and then assign the results of
1760 bool any_new = false;
1761 Typed_identifier_list::const_iterator p = vars->begin();
1762 Expression* init = type == NULL ? receive : NULL;
1763 Named_object* val_no = this->init_var(*p, type, init, is_coloneq,
1764 type == NULL, &any_new);
1765 if (type == NULL && any_new && val_no->is_variable())
1766 val_no->var_value()->set_type_from_init_tuple();
1767 Expression* val_var = Expression::make_var_reference(val_no, location);
1770 Type* var_type = type;
1771 if (var_type == NULL)
1772 var_type = Type::lookup_bool_type();
1773 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1775 Expression* received_var = Expression::make_var_reference(no, location);
1777 if (is_coloneq && !any_new)
1778 error_at(location, "variables redeclared but no variable is new");
1780 Statement* s = Statement::make_tuple_receive_assignment(val_var,
1786 if (!this->gogo_->in_global_scope())
1787 this->gogo_->add_statement(s);
1788 else if (!val_no->is_sink())
1790 if (val_no->is_variable())
1791 val_no->var_value()->add_preinit_statement(this->gogo_, s);
1793 else if (!no->is_sink())
1795 if (no->is_variable())
1796 no->var_value()->add_preinit_statement(this->gogo_, s);
1800 Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
1802 dummy->var_value()->add_preinit_statement(this->gogo_, s);
1808 // See if we need to initialize a pair of values from a type guard
1809 // expression. This returns true if we have set up the variables and
1810 // the initialization.
1813 Parse::init_vars_from_type_guard(const Typed_identifier_list* vars,
1814 Type* type, Expression* expr,
1815 bool is_coloneq, source_location location)
1817 Type_guard_expression* type_guard = expr->type_guard_expression();
1818 if (type_guard == NULL)
1820 if (vars->size() != 2)
1823 // This is a type guard expression which is being assigned to two
1824 // variables. Declare the variables, and then assign the results of
1826 bool any_new = false;
1827 Typed_identifier_list::const_iterator p = vars->begin();
1828 Type* var_type = type;
1829 if (var_type == NULL)
1830 var_type = type_guard->type();
1831 Named_object* val_no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1833 Expression* val_var = Expression::make_var_reference(val_no, location);
1837 if (var_type == NULL)
1838 var_type = Type::lookup_bool_type();
1839 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1841 Expression* ok_var = Expression::make_var_reference(no, location);
1843 Expression* texpr = type_guard->expr();
1844 Type* t = type_guard->type();
1845 Statement* s = Statement::make_tuple_type_guard_assignment(val_var, ok_var,
1849 if (is_coloneq && !any_new)
1850 error_at(location, "variables redeclared but no variable is new");
1852 if (!this->gogo_->in_global_scope())
1853 this->gogo_->add_statement(s);
1854 else if (!val_no->is_sink())
1856 if (val_no->is_variable())
1857 val_no->var_value()->add_preinit_statement(this->gogo_, s);
1859 else if (!no->is_sink())
1861 if (no->is_variable())
1862 no->var_value()->add_preinit_statement(this->gogo_, s);
1866 Named_object* dummy = this->create_dummy_global(type, NULL, location);
1867 dummy->var_value()->add_preinit_statement(this->gogo_, s);
1873 // Create a single variable. If IS_COLONEQ is true, we permit
1874 // redeclarations in the same block, and we set *IS_NEW when we find a
1875 // new variable which is not a redeclaration.
1878 Parse::init_var(const Typed_identifier& tid, Type* type, Expression* init,
1879 bool is_coloneq, bool type_from_init, bool* is_new)
1881 source_location location = tid.location();
1883 if (Gogo::is_sink_name(tid.name()))
1885 if (!type_from_init && init != NULL)
1887 if (!this->gogo_->in_global_scope())
1888 this->gogo_->add_statement(Statement::make_statement(init, true));
1890 return this->create_dummy_global(type, init, location);
1892 return this->gogo_->add_sink();
1897 Named_object* no = this->gogo_->lookup_in_block(tid.name());
1899 && (no->is_variable() || no->is_result_variable()))
1901 // INIT may be NULL even when IS_COLONEQ is true for cases
1902 // like v, ok := x.(int).
1903 if (!type_from_init && init != NULL)
1905 Expression *v = Expression::make_var_reference(no, location);
1906 Statement *s = Statement::make_assignment(v, init, location);
1907 this->gogo_->add_statement(s);
1913 Variable* var = new Variable(type, init, this->gogo_->in_global_scope(),
1914 false, false, location);
1915 Named_object* no = this->gogo_->add_variable(tid.name(), var);
1916 if (!no->is_variable())
1918 // The name is already defined, so we just gave an error.
1919 return this->gogo_->add_sink();
1924 // Create a dummy global variable to force an initializer to be run in
1925 // the right place. This is used when a sink variable is initialized
1929 Parse::create_dummy_global(Type* type, Expression* init,
1930 source_location location)
1932 if (type == NULL && init == NULL)
1933 type = Type::lookup_bool_type();
1934 Variable* var = new Variable(type, init, true, false, false, location);
1937 snprintf(buf, sizeof buf, "_.%d", count);
1939 return this->gogo_->add_variable(buf, var);
1942 // SimpleVarDecl = identifier ":=" Expression .
1944 // We've already seen the identifier.
1946 // FIXME: We also have to implement
1947 // IdentifierList ":=" ExpressionList
1948 // In order to support both "a, b := 1, 0" and "a, b = 1, 0" we accept
1949 // tuple assignments here as well.
1951 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
1954 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
1955 // guard (var := expr.("type") using the literal keyword "type").
1958 Parse::simple_var_decl_or_assignment(const std::string& name,
1959 source_location location,
1960 Range_clause* p_range_clause,
1961 Type_switch* p_type_switch)
1963 Typed_identifier_list til;
1964 til.push_back(Typed_identifier(name, NULL, location));
1966 // We've seen one identifier. If we see a comma now, this could be
1968 if (this->peek_token()->is_op(OPERATOR_COMMA))
1970 go_assert(p_type_switch == NULL);
1973 const Token* token = this->advance_token();
1974 if (!token->is_identifier())
1977 std::string id = token->identifier();
1978 bool is_id_exported = token->is_identifier_exported();
1979 source_location id_location = token->location();
1981 token = this->advance_token();
1982 if (!token->is_op(OPERATOR_COMMA))
1984 if (token->is_op(OPERATOR_COLONEQ))
1986 id = this->gogo_->pack_hidden_name(id, is_id_exported);
1987 til.push_back(Typed_identifier(id, NULL, location));
1990 this->unget_token(Token::make_identifier_token(id,
1996 id = this->gogo_->pack_hidden_name(id, is_id_exported);
1997 til.push_back(Typed_identifier(id, NULL, location));
2000 // We have a comma separated list of identifiers in TIL. If the
2001 // next token is COLONEQ, then this is a simple var decl, and we
2002 // have the complete list of identifiers. If the next token is
2003 // not COLONEQ, then the only valid parse is a tuple assignment.
2004 // The list of identifiers we have so far is really a list of
2005 // expressions. There are more expressions following.
2007 if (!this->peek_token()->is_op(OPERATOR_COLONEQ))
2009 Expression_list* exprs = new Expression_list;
2010 for (Typed_identifier_list::const_iterator p = til.begin();
2013 exprs->push_back(this->id_to_expression(p->name(),
2016 Expression_list* more_exprs = this->expression_list(NULL, true);
2017 for (Expression_list::const_iterator p = more_exprs->begin();
2018 p != more_exprs->end();
2020 exprs->push_back(*p);
2023 this->tuple_assignment(exprs, p_range_clause);
2028 go_assert(this->peek_token()->is_op(OPERATOR_COLONEQ));
2029 const Token* token = this->advance_token();
2031 if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
2033 this->range_clause_decl(&til, p_range_clause);
2037 Expression_list* init;
2038 if (p_type_switch == NULL)
2039 init = this->expression_list(NULL, false);
2042 bool is_type_switch = false;
2043 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true,
2047 p_type_switch->found = true;
2048 p_type_switch->name = name;
2049 p_type_switch->location = location;
2050 p_type_switch->expr = expr;
2054 if (!this->peek_token()->is_op(OPERATOR_COMMA))
2056 init = new Expression_list();
2057 init->push_back(expr);
2061 this->advance_token();
2062 init = this->expression_list(expr, false);
2066 this->init_vars(&til, NULL, init, true, location);
2069 // FunctionDecl = "func" identifier Signature [ Block ] .
2070 // MethodDecl = "func" Receiver identifier Signature [ Block ] .
2073 // FunctionDecl = "func" identifier Signature
2074 // __asm__ "(" string_lit ")" .
2075 // This extension means a function whose real name is the identifier
2079 Parse::function_decl()
2081 go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
2082 source_location location = this->location();
2083 const Token* token = this->advance_token();
2085 Typed_identifier* rec = NULL;
2086 if (token->is_op(OPERATOR_LPAREN))
2088 rec = this->receiver();
2089 token = this->peek_token();
2092 if (!token->is_identifier())
2094 error_at(this->location(), "expected function name");
2099 this->gogo_->pack_hidden_name(token->identifier(),
2100 token->is_identifier_exported());
2102 this->advance_token();
2104 Function_type* fntype = this->signature(rec, this->location());
2108 Named_object* named_object = NULL;
2110 if (this->peek_token()->is_keyword(KEYWORD_ASM))
2112 if (!this->advance_token()->is_op(OPERATOR_LPAREN))
2114 error_at(this->location(), "expected %<(%>");
2117 token = this->advance_token();
2118 if (!token->is_string())
2120 error_at(this->location(), "expected string");
2123 std::string asm_name = token->string_value();
2124 if (!this->advance_token()->is_op(OPERATOR_RPAREN))
2126 error_at(this->location(), "expected %<)%>");
2129 this->advance_token();
2130 if (!Gogo::is_sink_name(name))
2132 named_object = this->gogo_->declare_function(name, fntype, location);
2133 if (named_object->is_function_declaration())
2134 named_object->func_declaration_value()->set_asm_name(asm_name);
2138 // Check for the easy error of a newline before the opening brace.
2139 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
2141 source_location semi_loc = this->location();
2142 if (this->advance_token()->is_op(OPERATOR_LCURLY))
2143 error_at(this->location(),
2144 "unexpected semicolon or newline before %<{%>");
2146 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
2150 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
2152 if (named_object == NULL && !Gogo::is_sink_name(name))
2153 this->gogo_->declare_function(name, fntype, location);
2157 this->gogo_->start_function(name, fntype, true, location);
2158 source_location end_loc = this->block();
2159 this->gogo_->finish_function(end_loc);
2163 // Receiver = "(" [ identifier ] [ "*" ] BaseTypeName ")" .
2164 // BaseTypeName = identifier .
2169 go_assert(this->peek_token()->is_op(OPERATOR_LPAREN));
2172 const Token* token = this->advance_token();
2173 source_location location = token->location();
2174 if (!token->is_op(OPERATOR_MULT))
2176 if (!token->is_identifier())
2178 error_at(this->location(), "method has no receiver");
2179 while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
2180 token = this->advance_token();
2181 if (!token->is_eof())
2182 this->advance_token();
2185 name = token->identifier();
2186 bool is_exported = token->is_identifier_exported();
2187 token = this->advance_token();
2188 if (!token->is_op(OPERATOR_DOT) && !token->is_op(OPERATOR_RPAREN))
2190 // An identifier followed by something other than a dot or a
2191 // right parenthesis must be a receiver name followed by a
2193 name = this->gogo_->pack_hidden_name(name, is_exported);
2197 // This must be a type name.
2198 this->unget_token(Token::make_identifier_token(name, is_exported,
2200 token = this->peek_token();
2205 // Here the receiver name is in NAME (it is empty if the receiver is
2206 // unnamed) and TOKEN is the first token in the type.
2208 bool is_pointer = false;
2209 if (token->is_op(OPERATOR_MULT))
2212 token = this->advance_token();
2215 if (!token->is_identifier())
2217 error_at(this->location(), "expected receiver name or type");
2218 int c = token->is_op(OPERATOR_LPAREN) ? 1 : 0;
2219 while (!token->is_eof())
2221 token = this->advance_token();
2222 if (token->is_op(OPERATOR_LPAREN))
2224 else if (token->is_op(OPERATOR_RPAREN))
2231 if (!token->is_eof())
2232 this->advance_token();
2236 Type* type = this->type_name(true);
2238 if (is_pointer && !type->is_error_type())
2239 type = Type::make_pointer_type(type);
2241 if (this->peek_token()->is_op(OPERATOR_RPAREN))
2242 this->advance_token();
2245 if (this->peek_token()->is_op(OPERATOR_COMMA))
2246 error_at(this->location(), "method has multiple receivers");
2248 error_at(this->location(), "expected %<)%>");
2249 while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
2250 token = this->advance_token();
2251 if (!token->is_eof())
2252 this->advance_token();
2256 return new Typed_identifier(name, type, location);
2259 // Operand = Literal | QualifiedIdent | MethodExpr | "(" Expression ")" .
2260 // Literal = BasicLit | CompositeLit | FunctionLit .
2261 // BasicLit = int_lit | float_lit | imaginary_lit | char_lit | string_lit .
2263 // If MAY_BE_SINK is true, this operand may be "_".
2266 Parse::operand(bool may_be_sink)
2268 const Token* token = this->peek_token();
2270 switch (token->classification())
2272 case Token::TOKEN_IDENTIFIER:
2274 source_location location = token->location();
2275 std::string id = token->identifier();
2276 bool is_exported = token->is_identifier_exported();
2277 std::string packed = this->gogo_->pack_hidden_name(id, is_exported);
2279 Named_object* in_function;
2280 Named_object* named_object = this->gogo_->lookup(packed, &in_function);
2282 Package* package = NULL;
2283 if (named_object != NULL && named_object->is_package())
2285 if (!this->advance_token()->is_op(OPERATOR_DOT)
2286 || !this->advance_token()->is_identifier())
2288 error_at(location, "unexpected reference to package");
2289 return Expression::make_error(location);
2291 package = named_object->package_value();
2292 package->set_used();
2293 id = this->peek_token()->identifier();
2294 is_exported = this->peek_token()->is_identifier_exported();
2295 packed = this->gogo_->pack_hidden_name(id, is_exported);
2296 named_object = package->lookup(packed);
2297 location = this->location();
2298 go_assert(in_function == NULL);
2301 this->advance_token();
2303 if (named_object != NULL
2304 && named_object->is_type()
2305 && !named_object->type_value()->is_visible())
2307 go_assert(package != NULL);
2308 error_at(location, "invalid reference to hidden type %<%s.%s%>",
2309 Gogo::message_name(package->name()).c_str(),
2310 Gogo::message_name(id).c_str());
2311 return Expression::make_error(location);
2315 if (named_object == NULL)
2317 if (package != NULL)
2319 std::string n1 = Gogo::message_name(package->name());
2320 std::string n2 = Gogo::message_name(id);
2323 ("invalid reference to unexported identifier "
2325 n1.c_str(), n2.c_str());
2328 "reference to undefined identifier %<%s.%s%>",
2329 n1.c_str(), n2.c_str());
2330 return Expression::make_error(location);
2333 named_object = this->gogo_->add_unknown_name(packed, location);
2336 if (in_function != NULL
2337 && in_function != this->gogo_->current_function()
2338 && (named_object->is_variable()
2339 || named_object->is_result_variable()))
2340 return this->enclosing_var_reference(in_function, named_object,
2343 switch (named_object->classification())
2345 case Named_object::NAMED_OBJECT_CONST:
2346 return Expression::make_const_reference(named_object, location);
2347 case Named_object::NAMED_OBJECT_TYPE:
2348 return Expression::make_type(named_object->type_value(), location);
2349 case Named_object::NAMED_OBJECT_TYPE_DECLARATION:
2351 Type* t = Type::make_forward_declaration(named_object);
2352 return Expression::make_type(t, location);
2354 case Named_object::NAMED_OBJECT_VAR:
2355 case Named_object::NAMED_OBJECT_RESULT_VAR:
2356 return Expression::make_var_reference(named_object, location);
2357 case Named_object::NAMED_OBJECT_SINK:
2359 return Expression::make_sink(location);
2362 error_at(location, "cannot use _ as value");
2363 return Expression::make_error(location);
2365 case Named_object::NAMED_OBJECT_FUNC:
2366 case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
2367 return Expression::make_func_reference(named_object, NULL,
2369 case Named_object::NAMED_OBJECT_UNKNOWN:
2370 return Expression::make_unknown_reference(named_object, location);
2377 case Token::TOKEN_STRING:
2378 ret = Expression::make_string(token->string_value(), token->location());
2379 this->advance_token();
2382 case Token::TOKEN_INTEGER:
2383 ret = Expression::make_integer(token->integer_value(), NULL,
2385 this->advance_token();
2388 case Token::TOKEN_FLOAT:
2389 ret = Expression::make_float(token->float_value(), NULL,
2391 this->advance_token();
2394 case Token::TOKEN_IMAGINARY:
2397 mpfr_init_set_ui(zero, 0, GMP_RNDN);
2398 ret = Expression::make_complex(&zero, token->imaginary_value(),
2399 NULL, token->location());
2401 this->advance_token();
2405 case Token::TOKEN_KEYWORD:
2406 switch (token->keyword())
2409 return this->function_lit();
2411 case KEYWORD_INTERFACE:
2413 case KEYWORD_STRUCT:
2415 source_location location = token->location();
2416 return Expression::make_type(this->type(), location);
2423 case Token::TOKEN_OPERATOR:
2424 if (token->is_op(OPERATOR_LPAREN))
2426 this->advance_token();
2427 ret = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2428 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2429 error_at(this->location(), "missing %<)%>");
2431 this->advance_token();
2434 else if (token->is_op(OPERATOR_LSQUARE))
2436 // Here we call array_type directly, as this is the only
2437 // case where an ellipsis is permitted for an array type.
2438 source_location location = token->location();
2439 return Expression::make_type(this->array_type(true), location);
2447 error_at(this->location(), "expected operand");
2448 return Expression::make_error(this->location());
2451 // Handle a reference to a variable in an enclosing function. We add
2452 // it to a list of such variables. We return a reference to a field
2453 // in a struct which will be passed on the static chain when calling
2454 // the current function.
2457 Parse::enclosing_var_reference(Named_object* in_function, Named_object* var,
2458 source_location location)
2460 go_assert(var->is_variable() || var->is_result_variable());
2462 Named_object* this_function = this->gogo_->current_function();
2463 Named_object* closure = this_function->func_value()->closure_var();
2465 Enclosing_var ev(var, in_function, this->enclosing_vars_.size());
2466 std::pair<Enclosing_vars::iterator, bool> ins =
2467 this->enclosing_vars_.insert(ev);
2470 // This is a variable we have not seen before. Add a new field
2471 // to the closure type.
2472 this_function->func_value()->add_closure_field(var, location);
2475 Expression* closure_ref = Expression::make_var_reference(closure,
2477 closure_ref = Expression::make_unary(OPERATOR_MULT, closure_ref, location);
2479 // The closure structure holds pointers to the variables, so we need
2480 // to introduce an indirection.
2481 Expression* e = Expression::make_field_reference(closure_ref,
2484 e = Expression::make_unary(OPERATOR_MULT, e, location);
2488 // CompositeLit = LiteralType LiteralValue .
2489 // LiteralType = StructType | ArrayType | "[" "..." "]" ElementType |
2490 // SliceType | MapType | TypeName .
2491 // LiteralValue = "{" [ ElementList [ "," ] ] "}" .
2492 // ElementList = Element { "," Element } .
2493 // Element = [ Key ":" ] Value .
2494 // Key = FieldName | ElementIndex .
2495 // FieldName = identifier .
2496 // ElementIndex = Expression .
2497 // Value = Expression | LiteralValue .
2499 // We have already seen the type if there is one, and we are now
2500 // looking at the LiteralValue. The case "[" "..." "]" ElementType
2501 // will be seen here as an array type whose length is "nil". The
2502 // DEPTH parameter is non-zero if this is an embedded composite
2503 // literal and the type was omitted. It gives the number of steps up
2504 // to the type which was provided. E.g., in [][]int{{1}} it will be
2505 // 1. In [][][]int{{{1}}} it will be 2.
2508 Parse::composite_lit(Type* type, int depth, source_location location)
2510 go_assert(this->peek_token()->is_op(OPERATOR_LCURLY));
2511 this->advance_token();
2513 if (this->peek_token()->is_op(OPERATOR_RCURLY))
2515 this->advance_token();
2516 return Expression::make_composite_literal(type, depth, false, NULL,
2520 bool has_keys = false;
2521 Expression_list* vals = new Expression_list;
2525 bool is_type_omitted = false;
2527 const Token* token = this->peek_token();
2529 if (token->is_identifier())
2531 std::string identifier = token->identifier();
2532 bool is_exported = token->is_identifier_exported();
2533 source_location location = token->location();
2535 if (this->advance_token()->is_op(OPERATOR_COLON))
2537 // This may be a field name. We don't know for sure--it
2538 // could also be an expression for an array index. We
2539 // don't want to parse it as an expression because may
2540 // trigger various errors, e.g., if this identifier
2541 // happens to be the name of a package.
2542 Gogo* gogo = this->gogo_;
2543 val = this->id_to_expression(gogo->pack_hidden_name(identifier,
2549 this->unget_token(Token::make_identifier_token(identifier,
2552 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2555 else if (!token->is_op(OPERATOR_LCURLY))
2556 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2559 // This must be a composite literal inside another composite
2560 // literal, with the type omitted for the inner one.
2561 val = this->composite_lit(type, depth + 1, token->location());
2562 is_type_omitted = true;
2565 token = this->peek_token();
2566 if (!token->is_op(OPERATOR_COLON))
2569 vals->push_back(NULL);
2573 if (is_type_omitted && !val->is_error_expression())
2575 error_at(this->location(), "unexpected %<:%>");
2576 val = Expression::make_error(this->location());
2579 this->advance_token();
2581 if (!has_keys && !vals->empty())
2583 Expression_list* newvals = new Expression_list;
2584 for (Expression_list::const_iterator p = vals->begin();
2588 newvals->push_back(NULL);
2589 newvals->push_back(*p);
2596 if (val->unknown_expression() != NULL)
2597 val->unknown_expression()->set_is_composite_literal_key();
2599 vals->push_back(val);
2601 if (!token->is_op(OPERATOR_LCURLY))
2602 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2605 // This must be a composite literal inside another
2606 // composite literal, with the type omitted for the
2608 val = this->composite_lit(type, depth + 1, token->location());
2611 token = this->peek_token();
2614 vals->push_back(val);
2616 if (token->is_op(OPERATOR_COMMA))
2618 if (this->advance_token()->is_op(OPERATOR_RCURLY))
2620 this->advance_token();
2624 else if (token->is_op(OPERATOR_RCURLY))
2626 this->advance_token();
2631 error_at(this->location(), "expected %<,%> or %<}%>");
2634 while (!token->is_eof()
2635 && (depth > 0 || !token->is_op(OPERATOR_RCURLY)))
2637 if (token->is_op(OPERATOR_LCURLY))
2639 else if (token->is_op(OPERATOR_RCURLY))
2641 token = this->advance_token();
2643 if (token->is_op(OPERATOR_RCURLY))
2644 this->advance_token();
2646 return Expression::make_error(location);
2650 return Expression::make_composite_literal(type, depth, has_keys, vals,
2654 // FunctionLit = "func" Signature Block .
2657 Parse::function_lit()
2659 source_location location = this->location();
2660 go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
2661 this->advance_token();
2663 Enclosing_vars hold_enclosing_vars;
2664 hold_enclosing_vars.swap(this->enclosing_vars_);
2666 Function_type* type = this->signature(NULL, location);
2668 type = Type::make_function_type(NULL, NULL, NULL, location);
2670 // For a function literal, the next token must be a '{'. If we
2671 // don't see that, then we may have a type expression.
2672 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
2673 return Expression::make_type(type, location);
2675 Bc_stack* hold_break_stack = this->break_stack_;
2676 Bc_stack* hold_continue_stack = this->continue_stack_;
2677 this->break_stack_ = NULL;
2678 this->continue_stack_ = NULL;
2680 Named_object* no = this->gogo_->start_function("", type, true, location);
2682 source_location end_loc = this->block();
2684 this->gogo_->finish_function(end_loc);
2686 if (this->break_stack_ != NULL)
2687 delete this->break_stack_;
2688 if (this->continue_stack_ != NULL)
2689 delete this->continue_stack_;
2690 this->break_stack_ = hold_break_stack;
2691 this->continue_stack_ = hold_continue_stack;
2693 hold_enclosing_vars.swap(this->enclosing_vars_);
2695 Expression* closure = this->create_closure(no, &hold_enclosing_vars,
2698 return Expression::make_func_reference(no, closure, location);
2701 // Create a closure for the nested function FUNCTION. This is based
2702 // on ENCLOSING_VARS, which is a list of all variables defined in
2703 // enclosing functions and referenced from FUNCTION. A closure is the
2704 // address of a struct which contains the addresses of all the
2705 // referenced variables. This returns NULL if no closure is required.
2708 Parse::create_closure(Named_object* function, Enclosing_vars* enclosing_vars,
2709 source_location location)
2711 if (enclosing_vars->empty())
2714 // Get the variables in order by their field index.
2716 size_t enclosing_var_count = enclosing_vars->size();
2717 std::vector<Enclosing_var> ev(enclosing_var_count);
2718 for (Enclosing_vars::const_iterator p = enclosing_vars->begin();
2719 p != enclosing_vars->end();
2721 ev[p->index()] = *p;
2723 // Build an initializer for a composite literal of the closure's
2726 Named_object* enclosing_function = this->gogo_->current_function();
2727 Expression_list* initializer = new Expression_list;
2728 for (size_t i = 0; i < enclosing_var_count; ++i)
2730 go_assert(ev[i].index() == i);
2731 Named_object* var = ev[i].var();
2733 if (ev[i].in_function() == enclosing_function)
2734 ref = Expression::make_var_reference(var, location);
2736 ref = this->enclosing_var_reference(ev[i].in_function(), var,
2738 Expression* refaddr = Expression::make_unary(OPERATOR_AND, ref,
2740 initializer->push_back(refaddr);
2743 Named_object* closure_var = function->func_value()->closure_var();
2744 Struct_type* st = closure_var->var_value()->type()->deref()->struct_type();
2745 Expression* cv = Expression::make_struct_composite_literal(st, initializer,
2747 return Expression::make_heap_composite(cv, location);
2750 // PrimaryExpr = Operand { Selector | Index | Slice | TypeGuard | Call } .
2752 // If MAY_BE_SINK is true, this expression may be "_".
2754 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
2757 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2758 // guard (var := expr.("type") using the literal keyword "type").
2761 Parse::primary_expr(bool may_be_sink, bool may_be_composite_lit,
2762 bool* is_type_switch)
2764 source_location start_loc = this->location();
2765 bool is_parenthesized = this->peek_token()->is_op(OPERATOR_LPAREN);
2767 Expression* ret = this->operand(may_be_sink);
2769 // An unknown name followed by a curly brace must be a composite
2770 // literal, and the unknown name must be a type.
2771 if (may_be_composite_lit
2772 && !is_parenthesized
2773 && ret->unknown_expression() != NULL
2774 && this->peek_token()->is_op(OPERATOR_LCURLY))
2776 Named_object* no = ret->unknown_expression()->named_object();
2777 Type* type = Type::make_forward_declaration(no);
2778 ret = Expression::make_type(type, ret->location());
2781 // We handle composite literals and type casts here, as it is the
2782 // easiest way to handle types which are in parentheses, as in
2784 if (ret->is_type_expression())
2786 if (this->peek_token()->is_op(OPERATOR_LCURLY))
2788 if (is_parenthesized)
2790 "cannot parenthesize type in composite literal");
2791 ret = this->composite_lit(ret->type(), 0, ret->location());
2793 else if (this->peek_token()->is_op(OPERATOR_LPAREN))
2795 source_location loc = this->location();
2796 this->advance_token();
2797 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true,
2799 if (this->peek_token()->is_op(OPERATOR_ELLIPSIS))
2801 error_at(this->location(),
2802 "invalid use of %<...%> in type conversion");
2803 this->advance_token();
2805 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2806 error_at(this->location(), "expected %<)%>");
2808 this->advance_token();
2809 if (expr->is_error_expression())
2813 Type* t = ret->type();
2814 if (t->classification() == Type::TYPE_ARRAY
2815 && t->array_type()->length() != NULL
2816 && t->array_type()->length()->is_nil_expression())
2818 error_at(ret->location(),
2819 "invalid use of %<...%> in type conversion");
2820 ret = Expression::make_error(loc);
2823 ret = Expression::make_cast(t, expr, loc);
2830 const Token* token = this->peek_token();
2831 if (token->is_op(OPERATOR_LPAREN))
2832 ret = this->call(this->verify_not_sink(ret));
2833 else if (token->is_op(OPERATOR_DOT))
2835 ret = this->selector(this->verify_not_sink(ret), is_type_switch);
2836 if (is_type_switch != NULL && *is_type_switch)
2839 else if (token->is_op(OPERATOR_LSQUARE))
2840 ret = this->index(this->verify_not_sink(ret));
2848 // Selector = "." identifier .
2849 // TypeGuard = "." "(" QualifiedIdent ")" .
2851 // Note that Operand can expand to QualifiedIdent, which contains a
2852 // ".". That is handled directly in operand when it sees a package
2855 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2856 // guard (var := expr.("type") using the literal keyword "type").
2859 Parse::selector(Expression* left, bool* is_type_switch)
2861 go_assert(this->peek_token()->is_op(OPERATOR_DOT));
2862 source_location location = this->location();
2864 const Token* token = this->advance_token();
2865 if (token->is_identifier())
2867 // This could be a field in a struct, or a method in an
2868 // interface, or a method associated with a type. We can't know
2869 // which until we have seen all the types.
2871 this->gogo_->pack_hidden_name(token->identifier(),
2872 token->is_identifier_exported());
2873 if (token->identifier() == "_")
2875 error_at(this->location(), "invalid use of %<_%>");
2876 name = this->gogo_->pack_hidden_name("blank", false);
2878 this->advance_token();
2879 return Expression::make_selector(left, name, location);
2881 else if (token->is_op(OPERATOR_LPAREN))
2883 this->advance_token();
2885 if (!this->peek_token()->is_keyword(KEYWORD_TYPE))
2886 type = this->type();
2889 if (is_type_switch != NULL)
2890 *is_type_switch = true;
2893 error_at(this->location(),
2894 "use of %<.(type)%> outside type switch");
2895 type = Type::make_error_type();
2897 this->advance_token();
2899 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2900 error_at(this->location(), "missing %<)%>");
2902 this->advance_token();
2903 if (is_type_switch != NULL && *is_type_switch)
2905 return Expression::make_type_guard(left, type, location);
2909 error_at(this->location(), "expected identifier or %<(%>");
2914 // Index = "[" Expression "]" .
2915 // Slice = "[" Expression ":" [ Expression ] "]" .
2918 Parse::index(Expression* expr)
2920 source_location location = this->location();
2921 go_assert(this->peek_token()->is_op(OPERATOR_LSQUARE));
2922 this->advance_token();
2925 if (!this->peek_token()->is_op(OPERATOR_COLON))
2926 start = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2930 mpz_init_set_ui(zero, 0);
2931 start = Expression::make_integer(&zero, NULL, location);
2935 Expression* end = NULL;
2936 if (this->peek_token()->is_op(OPERATOR_COLON))
2938 // We use nil to indicate a missing high expression.
2939 if (this->advance_token()->is_op(OPERATOR_RSQUARE))
2940 end = Expression::make_nil(this->location());
2942 end = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2944 if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
2945 error_at(this->location(), "missing %<]%>");
2947 this->advance_token();
2948 return Expression::make_index(expr, start, end, location);
2951 // Call = "(" [ ArgumentList [ "," ] ] ")" .
2952 // ArgumentList = ExpressionList [ "..." ] .
2955 Parse::call(Expression* func)
2957 go_assert(this->peek_token()->is_op(OPERATOR_LPAREN));
2958 Expression_list* args = NULL;
2959 bool is_varargs = false;
2960 const Token* token = this->advance_token();
2961 if (!token->is_op(OPERATOR_RPAREN))
2963 args = this->expression_list(NULL, false);
2964 token = this->peek_token();
2965 if (token->is_op(OPERATOR_ELLIPSIS))
2968 token = this->advance_token();
2971 if (token->is_op(OPERATOR_COMMA))
2972 token = this->advance_token();
2973 if (!token->is_op(OPERATOR_RPAREN))
2974 error_at(this->location(), "missing %<)%>");
2976 this->advance_token();
2977 if (func->is_error_expression())
2979 return Expression::make_call(func, args, is_varargs, func->location());
2982 // Return an expression for a single unqualified identifier.
2985 Parse::id_to_expression(const std::string& name, source_location location)
2987 Named_object* in_function;
2988 Named_object* named_object = this->gogo_->lookup(name, &in_function);
2989 if (named_object == NULL)
2990 named_object = this->gogo_->add_unknown_name(name, location);
2992 if (in_function != NULL
2993 && in_function != this->gogo_->current_function()
2994 && (named_object->is_variable() || named_object->is_result_variable()))
2995 return this->enclosing_var_reference(in_function, named_object,
2998 switch (named_object->classification())
3000 case Named_object::NAMED_OBJECT_CONST:
3001 return Expression::make_const_reference(named_object, location);
3002 case Named_object::NAMED_OBJECT_VAR:
3003 case Named_object::NAMED_OBJECT_RESULT_VAR:
3004 return Expression::make_var_reference(named_object, location);
3005 case Named_object::NAMED_OBJECT_SINK:
3006 return Expression::make_sink(location);
3007 case Named_object::NAMED_OBJECT_FUNC:
3008 case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
3009 return Expression::make_func_reference(named_object, NULL, location);
3010 case Named_object::NAMED_OBJECT_UNKNOWN:
3011 return Expression::make_unknown_reference(named_object, location);
3012 case Named_object::NAMED_OBJECT_PACKAGE:
3013 case Named_object::NAMED_OBJECT_TYPE:
3014 case Named_object::NAMED_OBJECT_TYPE_DECLARATION:
3015 // These cases can arise for a field name in a composite
3017 return Expression::make_unknown_reference(named_object, location);
3019 error_at(this->location(), "unexpected type of identifier");
3020 return Expression::make_error(location);
3024 // Expression = UnaryExpr { binary_op Expression } .
3026 // PRECEDENCE is the precedence of the current operator.
3028 // If MAY_BE_SINK is true, this expression may be "_".
3030 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3033 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3034 // guard (var := expr.("type") using the literal keyword "type").
3037 Parse::expression(Precedence precedence, bool may_be_sink,
3038 bool may_be_composite_lit, bool* is_type_switch)
3040 Expression* left = this->unary_expr(may_be_sink, may_be_composite_lit,
3045 if (is_type_switch != NULL && *is_type_switch)
3048 const Token* token = this->peek_token();
3049 if (token->classification() != Token::TOKEN_OPERATOR)
3055 Precedence right_precedence;
3056 switch (token->op())
3059 right_precedence = PRECEDENCE_OROR;
3061 case OPERATOR_ANDAND:
3062 right_precedence = PRECEDENCE_ANDAND;
3065 case OPERATOR_NOTEQ:
3070 right_precedence = PRECEDENCE_RELOP;
3073 case OPERATOR_MINUS:
3076 right_precedence = PRECEDENCE_ADDOP;
3081 case OPERATOR_LSHIFT:
3082 case OPERATOR_RSHIFT:
3084 case OPERATOR_BITCLEAR:
3085 right_precedence = PRECEDENCE_MULOP;
3088 right_precedence = PRECEDENCE_INVALID;
3092 if (right_precedence == PRECEDENCE_INVALID)
3098 Operator op = token->op();
3099 source_location binop_location = token->location();
3101 if (precedence >= right_precedence)
3103 // We've already seen A * B, and we see + C. We want to
3104 // return so that A * B becomes a group.
3108 this->advance_token();
3110 left = this->verify_not_sink(left);
3111 Expression* right = this->expression(right_precedence, false,
3112 may_be_composite_lit,
3114 left = Expression::make_binary(op, left, right, binop_location);
3119 Parse::expression_may_start_here()
3121 const Token* token = this->peek_token();
3122 switch (token->classification())
3124 case Token::TOKEN_INVALID:
3125 case Token::TOKEN_EOF:
3127 case Token::TOKEN_KEYWORD:
3128 switch (token->keyword())
3133 case KEYWORD_STRUCT:
3134 case KEYWORD_INTERFACE:
3139 case Token::TOKEN_IDENTIFIER:
3141 case Token::TOKEN_STRING:
3143 case Token::TOKEN_OPERATOR:
3144 switch (token->op())
3147 case OPERATOR_MINUS:
3151 case OPERATOR_CHANOP:
3153 case OPERATOR_LPAREN:
3154 case OPERATOR_LSQUARE:
3159 case Token::TOKEN_INTEGER:
3160 case Token::TOKEN_FLOAT:
3161 case Token::TOKEN_IMAGINARY:
3168 // UnaryExpr = unary_op UnaryExpr | PrimaryExpr .
3170 // If MAY_BE_SINK is true, this expression may be "_".
3172 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3175 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3176 // guard (var := expr.("type") using the literal keyword "type").
3179 Parse::unary_expr(bool may_be_sink, bool may_be_composite_lit,
3180 bool* is_type_switch)
3182 const Token* token = this->peek_token();
3183 if (token->is_op(OPERATOR_PLUS)
3184 || token->is_op(OPERATOR_MINUS)
3185 || token->is_op(OPERATOR_NOT)
3186 || token->is_op(OPERATOR_XOR)
3187 || token->is_op(OPERATOR_CHANOP)
3188 || token->is_op(OPERATOR_MULT)
3189 || token->is_op(OPERATOR_AND))
3191 source_location location = token->location();
3192 Operator op = token->op();
3193 this->advance_token();
3195 if (op == OPERATOR_CHANOP
3196 && this->peek_token()->is_keyword(KEYWORD_CHAN))
3198 // This is "<- chan" which must be the start of a type.
3199 this->unget_token(Token::make_operator_token(op, location));
3200 return Expression::make_type(this->type(), location);
3203 Expression* expr = this->unary_expr(false, may_be_composite_lit, NULL);
3204 if (expr->is_error_expression())
3206 else if (op == OPERATOR_MULT && expr->is_type_expression())
3207 expr = Expression::make_type(Type::make_pointer_type(expr->type()),
3209 else if (op == OPERATOR_AND && expr->is_composite_literal())
3210 expr = Expression::make_heap_composite(expr, location);
3211 else if (op != OPERATOR_CHANOP)
3212 expr = Expression::make_unary(op, expr, location);
3214 expr = Expression::make_receive(expr, location);
3218 return this->primary_expr(may_be_sink, may_be_composite_lit,
3223 // Declaration | LabeledStmt | SimpleStmt |
3224 // GoStmt | ReturnStmt | BreakStmt | ContinueStmt | GotoStmt |
3225 // FallthroughStmt | Block | IfStmt | SwitchStmt | SelectStmt | ForStmt |
3228 // LABEL is the label of this statement if it has one.
3231 Parse::statement(Label* label)
3233 const Token* token = this->peek_token();
3234 switch (token->classification())
3236 case Token::TOKEN_KEYWORD:
3238 switch (token->keyword())
3243 this->declaration();
3247 case KEYWORD_STRUCT:
3248 case KEYWORD_INTERFACE:
3249 this->simple_stat(true, NULL, NULL, NULL);
3253 this->go_or_defer_stat();
3255 case KEYWORD_RETURN:
3256 this->return_stat();
3261 case KEYWORD_CONTINUE:
3262 this->continue_stat();
3270 case KEYWORD_SWITCH:
3271 this->switch_stat(label);
3273 case KEYWORD_SELECT:
3274 this->select_stat(label);
3277 this->for_stat(label);
3280 error_at(this->location(), "expected statement");
3281 this->advance_token();
3287 case Token::TOKEN_IDENTIFIER:
3289 std::string identifier = token->identifier();
3290 bool is_exported = token->is_identifier_exported();
3291 source_location location = token->location();
3292 if (this->advance_token()->is_op(OPERATOR_COLON))
3294 this->advance_token();
3295 this->labeled_stmt(identifier, location);
3299 this->unget_token(Token::make_identifier_token(identifier,
3302 this->simple_stat(true, NULL, NULL, NULL);
3307 case Token::TOKEN_OPERATOR:
3308 if (token->is_op(OPERATOR_LCURLY))
3310 source_location location = token->location();
3311 this->gogo_->start_block(location);
3312 source_location end_loc = this->block();
3313 this->gogo_->add_block(this->gogo_->finish_block(end_loc),
3316 else if (!token->is_op(OPERATOR_SEMICOLON))
3317 this->simple_stat(true, NULL, NULL, NULL);
3320 case Token::TOKEN_STRING:
3321 case Token::TOKEN_INTEGER:
3322 case Token::TOKEN_FLOAT:
3323 case Token::TOKEN_IMAGINARY:
3324 this->simple_stat(true, NULL, NULL, NULL);
3328 error_at(this->location(), "expected statement");
3329 this->advance_token();
3335 Parse::statement_may_start_here()
3337 const Token* token = this->peek_token();
3338 switch (token->classification())
3340 case Token::TOKEN_KEYWORD:
3342 switch (token->keyword())
3349 case KEYWORD_STRUCT:
3350 case KEYWORD_INTERFACE:
3353 case KEYWORD_RETURN:
3355 case KEYWORD_CONTINUE:
3358 case KEYWORD_SWITCH:
3359 case KEYWORD_SELECT:
3369 case Token::TOKEN_IDENTIFIER:
3372 case Token::TOKEN_OPERATOR:
3373 if (token->is_op(OPERATOR_LCURLY)
3374 || token->is_op(OPERATOR_SEMICOLON))
3377 return this->expression_may_start_here();
3379 case Token::TOKEN_STRING:
3380 case Token::TOKEN_INTEGER:
3381 case Token::TOKEN_FLOAT:
3382 case Token::TOKEN_IMAGINARY:
3390 // LabeledStmt = Label ":" Statement .
3391 // Label = identifier .
3394 Parse::labeled_stmt(const std::string& label_name, source_location location)
3396 Label* label = this->gogo_->add_label_definition(label_name, location);
3398 if (this->peek_token()->is_op(OPERATOR_RCURLY))
3400 // This is a label at the end of a block. A program is
3401 // permitted to omit a semicolon here.
3405 if (!this->statement_may_start_here())
3407 // Mark the label as used to avoid a useless error about an
3409 label->set_is_used();
3411 error_at(location, "missing statement after label");
3412 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
3417 this->statement(label);
3420 // SimpleStmt = EmptyStmt | ExpressionStmt | SendStmt | IncDecStmt |
3421 // Assignment | ShortVarDecl .
3423 // EmptyStmt was handled in Parse::statement.
3425 // In order to make this work for if and switch statements, if
3426 // RETURN_EXP is not NULL, and we see an ExpressionStat, we return the
3427 // expression rather than adding an expression statement to the
3428 // current block. If we see something other than an ExpressionStat,
3429 // we add the statement, set *RETURN_EXP to true if we saw a send
3430 // statement, and return NULL. The handling of send statements is for
3431 // better error messages.
3433 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
3436 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
3437 // guard (var := expr.("type") using the literal keyword "type").
3440 Parse::simple_stat(bool may_be_composite_lit, bool* return_exp,
3441 Range_clause* p_range_clause, Type_switch* p_type_switch)
3443 const Token* token = this->peek_token();
3445 // An identifier follow by := is a SimpleVarDecl.
3446 if (token->is_identifier())
3448 std::string identifier = token->identifier();
3449 bool is_exported = token->is_identifier_exported();
3450 source_location location = token->location();
3452 token = this->advance_token();
3453 if (token->is_op(OPERATOR_COLONEQ)
3454 || token->is_op(OPERATOR_COMMA))
3456 identifier = this->gogo_->pack_hidden_name(identifier, is_exported);
3457 this->simple_var_decl_or_assignment(identifier, location,
3459 (token->is_op(OPERATOR_COLONEQ)
3465 this->unget_token(Token::make_identifier_token(identifier, is_exported,
3469 Expression* exp = this->expression(PRECEDENCE_NORMAL, true,
3470 may_be_composite_lit,
3471 (p_type_switch == NULL
3473 : &p_type_switch->found));
3474 if (p_type_switch != NULL && p_type_switch->found)
3476 p_type_switch->name.clear();
3477 p_type_switch->location = exp->location();
3478 p_type_switch->expr = this->verify_not_sink(exp);
3481 token = this->peek_token();
3482 if (token->is_op(OPERATOR_CHANOP))
3484 this->send_stmt(this->verify_not_sink(exp));
3485 if (return_exp != NULL)
3488 else if (token->is_op(OPERATOR_PLUSPLUS)
3489 || token->is_op(OPERATOR_MINUSMINUS))
3490 this->inc_dec_stat(this->verify_not_sink(exp));
3491 else if (token->is_op(OPERATOR_COMMA)
3492 || token->is_op(OPERATOR_EQ))
3493 this->assignment(exp, p_range_clause);
3494 else if (token->is_op(OPERATOR_PLUSEQ)
3495 || token->is_op(OPERATOR_MINUSEQ)
3496 || token->is_op(OPERATOR_OREQ)
3497 || token->is_op(OPERATOR_XOREQ)
3498 || token->is_op(OPERATOR_MULTEQ)
3499 || token->is_op(OPERATOR_DIVEQ)
3500 || token->is_op(OPERATOR_MODEQ)
3501 || token->is_op(OPERATOR_LSHIFTEQ)
3502 || token->is_op(OPERATOR_RSHIFTEQ)
3503 || token->is_op(OPERATOR_ANDEQ)
3504 || token->is_op(OPERATOR_BITCLEAREQ))
3505 this->assignment(this->verify_not_sink(exp), p_range_clause);
3506 else if (return_exp != NULL)
3507 return this->verify_not_sink(exp);
3510 exp = this->verify_not_sink(exp);
3512 if (token->is_op(OPERATOR_COLONEQ))
3514 if (!exp->is_error_expression())
3515 error_at(token->location(), "non-name on left side of %<:=%>");
3516 while (!token->is_op(OPERATOR_SEMICOLON)
3517 && !token->is_eof())
3518 token = this->advance_token();
3522 this->expression_stat(exp);
3529 Parse::simple_stat_may_start_here()
3531 return this->expression_may_start_here();
3534 // Parse { Statement ";" } which is used in a few places. The list of
3535 // statements may end with a right curly brace, in which case the
3536 // semicolon may be omitted.
3539 Parse::statement_list()
3541 while (this->statement_may_start_here())
3543 this->statement(NULL);
3544 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3545 this->advance_token();
3546 else if (this->peek_token()->is_op(OPERATOR_RCURLY))
3550 if (!this->peek_token()->is_eof() || !saw_errors())
3551 error_at(this->location(), "expected %<;%> or %<}%> or newline");
3552 if (!this->skip_past_error(OPERATOR_RCURLY))
3559 Parse::statement_list_may_start_here()
3561 return this->statement_may_start_here();
3564 // ExpressionStat = Expression .
3567 Parse::expression_stat(Expression* exp)
3569 this->gogo_->add_statement(Statement::make_statement(exp, false));
3572 // SendStmt = Channel "<-" Expression .
3573 // Channel = Expression .
3576 Parse::send_stmt(Expression* channel)
3578 go_assert(this->peek_token()->is_op(OPERATOR_CHANOP));
3579 source_location loc = this->location();
3580 this->advance_token();
3581 Expression* val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
3582 Statement* s = Statement::make_send_statement(channel, val, loc);
3583 this->gogo_->add_statement(s);
3586 // IncDecStat = Expression ( "++" | "--" ) .
3589 Parse::inc_dec_stat(Expression* exp)
3591 const Token* token = this->peek_token();
3593 // Lvalue maps require special handling.
3594 if (exp->index_expression() != NULL)
3595 exp->index_expression()->set_is_lvalue();
3597 if (token->is_op(OPERATOR_PLUSPLUS))
3598 this->gogo_->add_statement(Statement::make_inc_statement(exp));
3599 else if (token->is_op(OPERATOR_MINUSMINUS))
3600 this->gogo_->add_statement(Statement::make_dec_statement(exp));
3603 this->advance_token();
3606 // Assignment = ExpressionList assign_op ExpressionList .
3608 // EXP is an expression that we have already parsed.
3610 // If RANGE_CLAUSE is not NULL, then this will recognize a
3614 Parse::assignment(Expression* expr, Range_clause* p_range_clause)
3616 Expression_list* vars;
3617 if (!this->peek_token()->is_op(OPERATOR_COMMA))
3619 vars = new Expression_list();
3620 vars->push_back(expr);
3624 this->advance_token();
3625 vars = this->expression_list(expr, true);
3628 this->tuple_assignment(vars, p_range_clause);
3631 // An assignment statement. LHS is the list of expressions which
3632 // appear on the left hand side.
3634 // If RANGE_CLAUSE is not NULL, then this will recognize a
3638 Parse::tuple_assignment(Expression_list* lhs, Range_clause* p_range_clause)
3640 const Token* token = this->peek_token();
3641 if (!token->is_op(OPERATOR_EQ)
3642 && !token->is_op(OPERATOR_PLUSEQ)
3643 && !token->is_op(OPERATOR_MINUSEQ)
3644 && !token->is_op(OPERATOR_OREQ)
3645 && !token->is_op(OPERATOR_XOREQ)
3646 && !token->is_op(OPERATOR_MULTEQ)
3647 && !token->is_op(OPERATOR_DIVEQ)
3648 && !token->is_op(OPERATOR_MODEQ)
3649 && !token->is_op(OPERATOR_LSHIFTEQ)
3650 && !token->is_op(OPERATOR_RSHIFTEQ)
3651 && !token->is_op(OPERATOR_ANDEQ)
3652 && !token->is_op(OPERATOR_BITCLEAREQ))
3654 error_at(this->location(), "expected assignment operator");
3657 Operator op = token->op();
3658 source_location location = token->location();
3660 token = this->advance_token();
3662 if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
3664 if (op != OPERATOR_EQ)
3665 error_at(this->location(), "range clause requires %<=%>");
3666 this->range_clause_expr(lhs, p_range_clause);
3670 Expression_list* vals = this->expression_list(NULL, false);
3672 // We've parsed everything; check for errors.
3673 if (lhs == NULL || vals == NULL)
3675 for (Expression_list::const_iterator pe = lhs->begin();
3679 if ((*pe)->is_error_expression())
3681 if (op != OPERATOR_EQ && (*pe)->is_sink_expression())
3682 error_at((*pe)->location(), "cannot use _ as value");
3684 for (Expression_list::const_iterator pe = vals->begin();
3688 if ((*pe)->is_error_expression())
3692 // Map expressions act differently when they are lvalues.
3693 for (Expression_list::iterator plv = lhs->begin();
3696 if ((*plv)->index_expression() != NULL)
3697 (*plv)->index_expression()->set_is_lvalue();
3699 Call_expression* call;
3700 Index_expression* map_index;
3701 Receive_expression* receive;
3702 Type_guard_expression* type_guard;
3703 if (lhs->size() == vals->size())
3706 if (lhs->size() > 1)
3708 if (op != OPERATOR_EQ)
3709 error_at(location, "multiple values only permitted with %<=%>");
3710 s = Statement::make_tuple_assignment(lhs, vals, location);
3714 if (op == OPERATOR_EQ)
3715 s = Statement::make_assignment(lhs->front(), vals->front(),
3718 s = Statement::make_assignment_operation(op, lhs->front(),
3719 vals->front(), location);
3723 this->gogo_->add_statement(s);
3725 else if (vals->size() == 1
3726 && (call = (*vals->begin())->call_expression()) != NULL)
3728 if (op != OPERATOR_EQ)
3729 error_at(location, "multiple results only permitted with %<=%>");
3731 vals = new Expression_list;
3732 for (unsigned int i = 0; i < lhs->size(); ++i)
3733 vals->push_back(Expression::make_call_result(call, i));
3734 Statement* s = Statement::make_tuple_assignment(lhs, vals, location);
3735 this->gogo_->add_statement(s);
3737 else if (lhs->size() == 2
3738 && vals->size() == 1
3739 && (map_index = (*vals->begin())->index_expression()) != NULL)
3741 if (op != OPERATOR_EQ)
3742 error_at(location, "two values from map requires %<=%>");
3743 Expression* val = lhs->front();
3744 Expression* present = lhs->back();
3745 Statement* s = Statement::make_tuple_map_assignment(val, present,
3746 map_index, location);
3747 this->gogo_->add_statement(s);
3749 else if (lhs->size() == 1
3750 && vals->size() == 2
3751 && (map_index = lhs->front()->index_expression()) != NULL)
3753 if (op != OPERATOR_EQ)
3754 error_at(location, "assigning tuple to map index requires %<=%>");
3755 Expression* val = vals->front();
3756 Expression* should_set = vals->back();
3757 Statement* s = Statement::make_map_assignment(map_index, val, should_set,
3759 this->gogo_->add_statement(s);
3761 else if (lhs->size() == 2
3762 && vals->size() == 1
3763 && (receive = (*vals->begin())->receive_expression()) != NULL)
3765 if (op != OPERATOR_EQ)
3766 error_at(location, "two values from receive requires %<=%>");
3767 Expression* val = lhs->front();
3768 Expression* success = lhs->back();
3769 Expression* channel = receive->channel();
3770 Statement* s = Statement::make_tuple_receive_assignment(val, success,
3774 this->gogo_->add_statement(s);
3776 else if (lhs->size() == 2
3777 && vals->size() == 1
3778 && (type_guard = (*vals->begin())->type_guard_expression()) != NULL)
3780 if (op != OPERATOR_EQ)
3781 error_at(location, "two values from type guard requires %<=%>");
3782 Expression* val = lhs->front();
3783 Expression* ok = lhs->back();
3784 Expression* expr = type_guard->expr();
3785 Type* type = type_guard->type();
3786 Statement* s = Statement::make_tuple_type_guard_assignment(val, ok,
3789 this->gogo_->add_statement(s);
3793 error_at(location, "number of variables does not match number of values");
3797 // GoStat = "go" Expression .
3798 // DeferStat = "defer" Expression .
3801 Parse::go_or_defer_stat()
3803 go_assert(this->peek_token()->is_keyword(KEYWORD_GO)
3804 || this->peek_token()->is_keyword(KEYWORD_DEFER));
3805 bool is_go = this->peek_token()->is_keyword(KEYWORD_GO);
3806 source_location stat_location = this->location();
3807 this->advance_token();
3808 source_location expr_location = this->location();
3809 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
3810 Call_expression* call_expr = expr->call_expression();
3811 if (call_expr == NULL)
3813 error_at(expr_location, "expected call expression");
3817 // Make it easier to simplify go/defer statements by putting every
3818 // statement in its own block.
3819 this->gogo_->start_block(stat_location);
3822 stat = Statement::make_go_statement(call_expr, stat_location);
3824 stat = Statement::make_defer_statement(call_expr, stat_location);
3825 this->gogo_->add_statement(stat);
3826 this->gogo_->add_block(this->gogo_->finish_block(stat_location),
3830 // ReturnStat = "return" [ ExpressionList ] .
3833 Parse::return_stat()
3835 go_assert(this->peek_token()->is_keyword(KEYWORD_RETURN));
3836 source_location location = this->location();
3837 this->advance_token();
3838 Expression_list* vals = NULL;
3839 if (this->expression_may_start_here())
3840 vals = this->expression_list(NULL, false);
3841 this->gogo_->add_statement(Statement::make_return_statement(vals, location));
3844 // IfStmt = "if" [ SimpleStmt ";" ] Expression Block
3845 // [ "else" ( IfStmt | Block ) ] .
3850 go_assert(this->peek_token()->is_keyword(KEYWORD_IF));
3851 source_location location = this->location();
3852 this->advance_token();
3854 this->gogo_->start_block(location);
3856 bool saw_simple_stat = false;
3857 Expression* cond = NULL;
3859 if (this->simple_stat_may_start_here())
3861 cond = this->simple_stat(false, &saw_send_stmt, NULL, NULL);
3862 saw_simple_stat = true;
3864 if (cond != NULL && this->peek_token()->is_op(OPERATOR_SEMICOLON))
3866 // The SimpleStat is an expression statement.
3867 this->expression_stat(cond);
3872 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3873 this->advance_token();
3874 else if (saw_simple_stat)
3877 error_at(this->location(),
3878 ("send statement used as value; "
3879 "use select for non-blocking send"));
3881 error_at(this->location(),
3882 "expected %<;%> after statement in if expression");
3883 if (!this->expression_may_start_here())
3884 cond = Expression::make_error(this->location());
3886 if (cond == NULL && this->peek_token()->is_op(OPERATOR_LCURLY))
3888 error_at(this->location(),
3889 "missing condition in if statement");
3890 cond = Expression::make_error(this->location());
3893 cond = this->expression(PRECEDENCE_NORMAL, false, false, NULL);
3896 this->gogo_->start_block(this->location());
3897 source_location end_loc = this->block();
3898 Block* then_block = this->gogo_->finish_block(end_loc);
3900 // Check for the easy error of a newline before "else".
3901 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3903 source_location semi_loc = this->location();
3904 if (this->advance_token()->is_keyword(KEYWORD_ELSE))
3905 error_at(this->location(),
3906 "unexpected semicolon or newline before %<else%>");
3908 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
3912 Block* else_block = NULL;
3913 if (this->peek_token()->is_keyword(KEYWORD_ELSE))
3915 this->gogo_->start_block(this->location());
3916 const Token* token = this->advance_token();
3917 if (token->is_keyword(KEYWORD_IF))
3919 else if (token->is_op(OPERATOR_LCURLY))
3923 error_at(this->location(), "expected %<if%> or %<{%>");
3924 this->statement(NULL);
3926 else_block = this->gogo_->finish_block(this->location());
3929 this->gogo_->add_statement(Statement::make_if_statement(cond, then_block,
3933 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3937 // SwitchStmt = ExprSwitchStmt | TypeSwitchStmt .
3938 // ExprSwitchStmt = "switch" [ [ SimpleStat ] ";" ] [ Expression ]
3939 // "{" { ExprCaseClause } "}" .
3940 // TypeSwitchStmt = "switch" [ [ SimpleStat ] ";" ] TypeSwitchGuard
3941 // "{" { TypeCaseClause } "}" .
3942 // TypeSwitchGuard = [ identifier ":=" ] Expression "." "(" "type" ")" .
3945 Parse::switch_stat(Label* label)
3947 go_assert(this->peek_token()->is_keyword(KEYWORD_SWITCH));
3948 source_location location = this->location();
3949 this->advance_token();
3951 this->gogo_->start_block(location);
3953 bool saw_simple_stat = false;
3954 Expression* switch_val = NULL;
3956 Type_switch type_switch;
3957 if (this->simple_stat_may_start_here())
3959 switch_val = this->simple_stat(false, &saw_send_stmt, NULL,
3961 saw_simple_stat = true;
3963 if (switch_val != NULL && this->peek_token()->is_op(OPERATOR_SEMICOLON))
3965 // The SimpleStat is an expression statement.
3966 this->expression_stat(switch_val);
3969 if (switch_val == NULL && !type_switch.found)
3971 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3972 this->advance_token();
3973 else if (saw_simple_stat)
3976 error_at(this->location(),
3977 ("send statement used as value; "
3978 "use select for non-blocking send"));
3980 error_at(this->location(),
3981 "expected %<;%> after statement in switch expression");
3983 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3985 if (this->peek_token()->is_identifier())
3987 const Token* token = this->peek_token();
3988 std::string identifier = token->identifier();
3989 bool is_exported = token->is_identifier_exported();
3990 source_location id_loc = token->location();
3992 token = this->advance_token();
3993 bool is_coloneq = token->is_op(OPERATOR_COLONEQ);
3994 this->unget_token(Token::make_identifier_token(identifier,
3999 // This must be a TypeSwitchGuard.
4000 switch_val = this->simple_stat(false, &saw_send_stmt, NULL,
4002 if (!type_switch.found)
4004 if (switch_val == NULL
4005 || !switch_val->is_error_expression())
4007 error_at(id_loc, "expected type switch assignment");
4008 switch_val = Expression::make_error(id_loc);
4013 if (switch_val == NULL && !type_switch.found)
4015 switch_val = this->expression(PRECEDENCE_NORMAL, false, false,
4016 &type_switch.found);
4017 if (type_switch.found)
4019 type_switch.name.clear();
4020 type_switch.expr = switch_val;
4021 type_switch.location = switch_val->location();
4027 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
4029 source_location token_loc = this->location();
4030 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
4031 && this->advance_token()->is_op(OPERATOR_LCURLY))
4032 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
4033 else if (this->peek_token()->is_op(OPERATOR_COLONEQ))
4035 error_at(token_loc, "invalid variable name");
4036 this->advance_token();
4037 this->expression(PRECEDENCE_NORMAL, false, false,
4038 &type_switch.found);
4039 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
4040 this->advance_token();
4041 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
4043 if (type_switch.found)
4044 type_switch.expr = Expression::make_error(location);
4048 error_at(this->location(), "expected %<{%>");
4049 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
4054 this->advance_token();
4056 Statement* statement;
4057 if (type_switch.found)
4058 statement = this->type_switch_body(label, type_switch, location);
4060 statement = this->expr_switch_body(label, switch_val, location);
4062 if (statement != NULL)
4063 this->gogo_->add_statement(statement);
4065 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
4069 // The body of an expression switch.
4070 // "{" { ExprCaseClause } "}"
4073 Parse::expr_switch_body(Label* label, Expression* switch_val,
4074 source_location location)
4076 Switch_statement* statement = Statement::make_switch_statement(switch_val,
4079 this->push_break_statement(statement, label);
4081 Case_clauses* case_clauses = new Case_clauses();
4082 bool saw_default = false;
4083 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
4085 if (this->peek_token()->is_eof())
4088 error_at(this->location(), "missing %<}%>");
4091 this->expr_case_clause(case_clauses, &saw_default);
4093 this->advance_token();
4095 statement->add_clauses(case_clauses);
4097 this->pop_break_statement();
4102 // ExprCaseClause = ExprSwitchCase ":" [ StatementList ] .
4103 // FallthroughStat = "fallthrough" .
4106 Parse::expr_case_clause(Case_clauses* clauses, bool* saw_default)
4108 source_location location = this->location();
4110 bool is_default = false;
4111 Expression_list* vals = this->expr_switch_case(&is_default);
4113 if (!this->peek_token()->is_op(OPERATOR_COLON))
4116 error_at(this->location(), "expected %<:%>");
4120 this->advance_token();
4122 Block* statements = NULL;
4123 if (this->statement_list_may_start_here())
4125 this->gogo_->start_block(this->location());
4126 this->statement_list();
4127 statements = this->gogo_->finish_block(this->location());
4130 bool is_fallthrough = false;
4131 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH))
4133 is_fallthrough = true;
4134 if (this->advance_token()->is_op(OPERATOR_SEMICOLON))
4135 this->advance_token();
4142 error_at(location, "multiple defaults in switch");
4145 *saw_default = true;
4148 if (is_default || vals != NULL)
4149 clauses->add(vals, is_default, statements, is_fallthrough, location);
4152 // ExprSwitchCase = "case" ExpressionList | "default" .
4155 Parse::expr_switch_case(bool* is_default)
4157 const Token* token = this->peek_token();
4158 if (token->is_keyword(KEYWORD_CASE))
4160 this->advance_token();
4161 return this->expression_list(NULL, false);
4163 else if (token->is_keyword(KEYWORD_DEFAULT))
4165 this->advance_token();
4172 error_at(this->location(), "expected %<case%> or %<default%>");
4173 if (!token->is_op(OPERATOR_RCURLY))
4174 this->advance_token();
4179 // The body of a type switch.
4180 // "{" { TypeCaseClause } "}" .
4183 Parse::type_switch_body(Label* label, const Type_switch& type_switch,
4184 source_location location)
4186 Named_object* switch_no = NULL;
4187 if (!type_switch.name.empty())
4189 Variable* switch_var = new Variable(NULL, type_switch.expr, false, false,
4190 false, type_switch.location);
4191 switch_no = this->gogo_->add_variable(type_switch.name, switch_var);
4194 Type_switch_statement* statement =
4195 Statement::make_type_switch_statement(switch_no,
4201 this->push_break_statement(statement, label);
4203 Type_case_clauses* case_clauses = new Type_case_clauses();
4204 bool saw_default = false;
4205 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
4207 if (this->peek_token()->is_eof())
4209 error_at(this->location(), "missing %<}%>");
4212 this->type_case_clause(switch_no, case_clauses, &saw_default);
4214 this->advance_token();
4216 statement->add_clauses(case_clauses);
4218 this->pop_break_statement();
4223 // TypeCaseClause = TypeSwitchCase ":" [ StatementList ] .
4226 Parse::type_case_clause(Named_object* switch_no, Type_case_clauses* clauses,
4229 source_location location = this->location();
4231 std::vector<Type*> types;
4232 bool is_default = false;
4233 this->type_switch_case(&types, &is_default);
4235 if (!this->peek_token()->is_op(OPERATOR_COLON))
4236 error_at(this->location(), "expected %<:%>");
4238 this->advance_token();
4240 Block* statements = NULL;
4241 if (this->statement_list_may_start_here())
4243 this->gogo_->start_block(this->location());
4244 if (switch_no != NULL && types.size() == 1)
4246 Type* type = types.front();
4247 Expression* init = Expression::make_var_reference(switch_no,
4249 init = Expression::make_type_guard(init, type, location);
4250 Variable* v = new Variable(type, init, false, false, false,
4252 v->set_is_type_switch_var();
4253 this->gogo_->add_variable(switch_no->name(), v);
4255 this->statement_list();
4256 statements = this->gogo_->finish_block(this->location());
4259 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH))
4261 error_at(this->location(),
4262 "fallthrough is not permitted in a type switch");
4263 if (this->advance_token()->is_op(OPERATOR_SEMICOLON))
4264 this->advance_token();
4269 go_assert(types.empty());
4272 error_at(location, "multiple defaults in type switch");
4275 *saw_default = true;
4276 clauses->add(NULL, false, true, statements, location);
4278 else if (!types.empty())
4280 for (std::vector<Type*>::const_iterator p = types.begin();
4281 p + 1 != types.end();
4283 clauses->add(*p, true, false, NULL, location);
4284 clauses->add(types.back(), false, false, statements, location);
4287 clauses->add(Type::make_error_type(), false, false, statements, location);
4290 // TypeSwitchCase = "case" type | "default"
4292 // We accept a comma separated list of types.
4295 Parse::type_switch_case(std::vector<Type*>* types, bool* is_default)
4297 const Token* token = this->peek_token();
4298 if (token->is_keyword(KEYWORD_CASE))
4300 this->advance_token();
4303 Type* t = this->type();
4305 if (!t->is_error_type())
4306 types->push_back(t);
4309 token = this->peek_token();
4310 while (!token->is_op(OPERATOR_COLON)
4311 && !token->is_op(OPERATOR_COMMA)
4312 && !token->is_op(OPERATOR_RCURLY)
4313 && !token->is_eof())
4314 token = this->advance_token();
4317 if (!this->peek_token()->is_op(OPERATOR_COMMA))
4319 this->advance_token();
4322 else if (token->is_keyword(KEYWORD_DEFAULT))
4324 this->advance_token();
4329 error_at(this->location(), "expected %<case%> or %<default%>");
4330 if (!token->is_op(OPERATOR_RCURLY))
4331 this->advance_token();
4335 // SelectStat = "select" "{" { CommClause } "}" .
4338 Parse::select_stat(Label* label)
4340 go_assert(this->peek_token()->is_keyword(KEYWORD_SELECT));
4341 source_location location = this->location();
4342 const Token* token = this->advance_token();
4344 if (!token->is_op(OPERATOR_LCURLY))
4346 source_location token_loc = token->location();
4347 if (token->is_op(OPERATOR_SEMICOLON)
4348 && this->advance_token()->is_op(OPERATOR_LCURLY))
4349 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
4352 error_at(this->location(), "expected %<{%>");
4356 this->advance_token();
4358 Select_statement* statement = Statement::make_select_statement(location);
4360 this->push_break_statement(statement, label);
4362 Select_clauses* select_clauses = new Select_clauses();
4363 bool saw_default = false;
4364 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
4366 if (this->peek_token()->is_eof())
4368 error_at(this->location(), "expected %<}%>");
4371 this->comm_clause(select_clauses, &saw_default);
4374 this->advance_token();
4376 statement->add_clauses(select_clauses);
4378 this->pop_break_statement();
4380 this->gogo_->add_statement(statement);
4383 // CommClause = CommCase ":" { Statement ";" } .
4386 Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
4388 source_location location = this->location();
4389 bool is_send = false;
4390 Expression* channel = NULL;
4391 Expression* val = NULL;
4392 Expression* closed = NULL;
4393 std::string varname;
4394 std::string closedname;
4395 bool is_default = false;
4396 bool got_case = this->comm_case(&is_send, &channel, &val, &closed,
4397 &varname, &closedname, &is_default);
4401 && closedname.empty()
4403 && val->index_expression() != NULL)
4404 val->index_expression()->set_is_lvalue();
4406 if (this->peek_token()->is_op(OPERATOR_COLON))
4407 this->advance_token();
4409 error_at(this->location(), "expected colon");
4411 this->gogo_->start_block(this->location());
4413 Named_object* var = NULL;
4414 if (!varname.empty())
4416 // FIXME: LOCATION is slightly wrong here.
4417 Variable* v = new Variable(NULL, channel, false, false, false,
4419 v->set_type_from_chan_element();
4420 var = this->gogo_->add_variable(varname, v);
4423 Named_object* closedvar = NULL;
4424 if (!closedname.empty())
4426 // FIXME: LOCATION is slightly wrong here.
4427 Variable* v = new Variable(Type::lookup_bool_type(), NULL,
4428 false, false, false, location);
4429 closedvar = this->gogo_->add_variable(closedname, v);
4432 this->statement_list();
4434 Block* statements = this->gogo_->finish_block(this->location());
4440 error_at(location, "multiple defaults in select");
4443 *saw_default = true;
4447 clauses->add(is_send, channel, val, closed, var, closedvar, is_default,
4448 statements, location);
4449 else if (statements != NULL)
4451 // Add the statements to make sure that any names they define
4453 this->gogo_->add_block(statements, location);
4457 // CommCase = "case" ( SendStmt | RecvStmt ) | "default" .
4460 Parse::comm_case(bool* is_send, Expression** channel, Expression** val,
4461 Expression** closed, std::string* varname,
4462 std::string* closedname, bool* is_default)
4464 const Token* token = this->peek_token();
4465 if (token->is_keyword(KEYWORD_DEFAULT))
4467 this->advance_token();
4470 else if (token->is_keyword(KEYWORD_CASE))
4472 this->advance_token();
4473 if (!this->send_or_recv_stmt(is_send, channel, val, closed, varname,
4479 error_at(this->location(), "expected %<case%> or %<default%>");
4480 if (!token->is_op(OPERATOR_RCURLY))
4481 this->advance_token();
4488 // RecvStmt = [ Expression [ "," Expression ] ( "=" | ":=" ) ] RecvExpr .
4489 // RecvExpr = Expression .
4492 Parse::send_or_recv_stmt(bool* is_send, Expression** channel, Expression** val,
4493 Expression** closed, std::string* varname,
4494 std::string* closedname)
4496 const Token* token = this->peek_token();
4497 bool saw_comma = false;
4498 bool closed_is_id = false;
4499 if (token->is_identifier())
4501 Gogo* gogo = this->gogo_;
4502 std::string recv_var = token->identifier();
4503 bool is_rv_exported = token->is_identifier_exported();
4504 source_location recv_var_loc = token->location();
4505 token = this->advance_token();
4506 if (token->is_op(OPERATOR_COLONEQ))
4509 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4511 error_at(this->location(), "expected %<<-%>");
4514 if (recv_var == "_")
4516 error_at(recv_var_loc,
4517 "no new variables on left side of %<:=%>");
4521 *varname = gogo->pack_hidden_name(recv_var, is_rv_exported);
4522 this->advance_token();
4523 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4526 else if (token->is_op(OPERATOR_COMMA))
4528 token = this->advance_token();
4529 if (token->is_identifier())
4531 std::string recv_closed = token->identifier();
4532 bool is_rc_exported = token->is_identifier_exported();
4533 source_location recv_closed_loc = token->location();
4534 closed_is_id = true;
4536 token = this->advance_token();
4537 if (token->is_op(OPERATOR_COLONEQ))
4539 // case rv, rc := <-c:
4540 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4542 error_at(this->location(), "expected %<<-%>");
4545 if (recv_var == "_" && recv_closed == "_")
4547 error_at(recv_var_loc,
4548 "no new variables on left side of %<:=%>");
4552 if (recv_var != "_")
4553 *varname = gogo->pack_hidden_name(recv_var,
4555 if (recv_closed != "_")
4556 *closedname = gogo->pack_hidden_name(recv_closed,
4558 this->advance_token();
4559 *channel = this->expression(PRECEDENCE_NORMAL, false, true,
4564 this->unget_token(Token::make_identifier_token(recv_closed,
4569 *val = this->id_to_expression(gogo->pack_hidden_name(recv_var,
4575 this->unget_token(Token::make_identifier_token(recv_var,
4580 // If SAW_COMMA is false, then we are looking at the start of the
4581 // send or receive expression. If SAW_COMMA is true, then *VAL is
4582 // set and we just read a comma.
4585 if (saw_comma || !this->peek_token()->is_op(OPERATOR_CHANOP))
4586 e = this->expression(PRECEDENCE_NORMAL, true, true, NULL);
4591 this->advance_token();
4592 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4594 // The next token should be ':'. If it is '<-', then we have
4596 // which is to say, send on a channel received from a channel.
4597 if (!this->peek_token()->is_op(OPERATOR_CHANOP))
4600 e = Expression::make_receive(*channel, (*channel)->location());
4603 if (this->peek_token()->is_op(OPERATOR_EQ))
4605 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4607 error_at(this->location(), "missing %<<-%>");
4611 this->advance_token();
4612 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4616 // *VAL is already set.
4617 if (!e->is_sink_expression())
4623 if (!e->is_sink_expression())
4632 error_at(this->location(), "expected %<=%> or %<:=%>");
4634 error_at(this->location(), "expected %<=%>");
4638 if (this->peek_token()->is_op(OPERATOR_CHANOP))
4642 *channel = this->verify_not_sink(e);
4643 this->advance_token();
4644 *val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4648 error_at(this->location(), "expected %<<-%> or %<=%>");
4652 // ForStat = "for" [ Condition | ForClause | RangeClause ] Block .
4653 // Condition = Expression .
4656 Parse::for_stat(Label* label)
4658 go_assert(this->peek_token()->is_keyword(KEYWORD_FOR));
4659 source_location location = this->location();
4660 const Token* token = this->advance_token();
4662 // Open a block to hold any variables defined in the init statement
4663 // of the for statement.
4664 this->gogo_->start_block(location);
4667 Expression* cond = NULL;
4669 Range_clause range_clause;
4671 if (!token->is_op(OPERATOR_LCURLY))
4673 if (token->is_keyword(KEYWORD_VAR))
4675 error_at(this->location(),
4676 "var declaration not allowed in for initializer");
4680 if (token->is_op(OPERATOR_SEMICOLON))
4681 this->for_clause(&cond, &post);
4684 // We might be looking at a Condition, an InitStat, or a
4687 cond = this->simple_stat(false, &saw_send_stmt, &range_clause, NULL);
4688 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
4690 if (cond == NULL && !range_clause.found)
4693 error_at(this->location(),
4694 ("send statement used as value; "
4695 "use select for non-blocking send"));
4697 error_at(this->location(), "parse error in for statement");
4702 if (range_clause.found)
4703 error_at(this->location(), "parse error after range clause");
4707 // COND is actually an expression statement for
4708 // InitStat at the start of a ForClause.
4709 this->expression_stat(cond);
4713 this->for_clause(&cond, &post);
4718 // Build the For_statement and note that it is the current target
4719 // for break and continue statements.
4721 For_statement* sfor;
4722 For_range_statement* srange;
4724 if (!range_clause.found)
4726 sfor = Statement::make_for_statement(init, cond, post, location);
4732 srange = Statement::make_for_range_statement(range_clause.index,
4740 this->push_break_statement(s, label);
4741 this->push_continue_statement(s, label);
4743 // Gather the block of statements in the loop and add them to the
4746 this->gogo_->start_block(this->location());
4747 source_location end_loc = this->block();
4748 Block* statements = this->gogo_->finish_block(end_loc);
4751 sfor->add_statements(statements);
4753 srange->add_statements(statements);
4755 // This is no longer the break/continue target.
4756 this->pop_break_statement();
4757 this->pop_continue_statement();
4759 // Add the For_statement to the list of statements, and close out
4760 // the block we started to hold any variables defined in the for
4763 this->gogo_->add_statement(s);
4765 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
4769 // ForClause = [ InitStat ] ";" [ Condition ] ";" [ PostStat ] .
4770 // InitStat = SimpleStat .
4771 // PostStat = SimpleStat .
4773 // We have already read InitStat at this point.
4776 Parse::for_clause(Expression** cond, Block** post)
4778 go_assert(this->peek_token()->is_op(OPERATOR_SEMICOLON));
4779 this->advance_token();
4780 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
4782 else if (this->peek_token()->is_op(OPERATOR_LCURLY))
4784 error_at(this->location(),
4785 "unexpected semicolon or newline before %<{%>");
4791 *cond = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4792 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
4793 error_at(this->location(), "expected semicolon");
4795 this->advance_token();
4797 if (this->peek_token()->is_op(OPERATOR_LCURLY))
4801 this->gogo_->start_block(this->location());
4802 this->simple_stat(false, NULL, NULL, NULL);
4803 *post = this->gogo_->finish_block(this->location());
4807 // RangeClause = IdentifierList ( "=" | ":=" ) "range" Expression .
4809 // This is the := version. It is called with a list of identifiers.
4812 Parse::range_clause_decl(const Typed_identifier_list* til,
4813 Range_clause* p_range_clause)
4815 go_assert(this->peek_token()->is_keyword(KEYWORD_RANGE));
4816 source_location location = this->location();
4818 p_range_clause->found = true;
4820 go_assert(til->size() >= 1);
4821 if (til->size() > 2)
4822 error_at(this->location(), "too many variables for range clause");
4824 this->advance_token();
4825 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, false, NULL);
4826 p_range_clause->range = expr;
4828 bool any_new = false;
4830 const Typed_identifier* pti = &til->front();
4831 Named_object* no = this->init_var(*pti, NULL, expr, true, true, &any_new);
4832 if (any_new && no->is_variable())
4833 no->var_value()->set_type_from_range_index();
4834 p_range_clause->index = Expression::make_var_reference(no, location);
4836 if (til->size() == 1)
4837 p_range_clause->value = NULL;
4841 bool is_new = false;
4842 no = this->init_var(*pti, NULL, expr, true, true, &is_new);
4843 if (is_new && no->is_variable())
4844 no->var_value()->set_type_from_range_value();
4847 p_range_clause->value = Expression::make_var_reference(no, location);
4851 error_at(location, "variables redeclared but no variable is new");
4854 // The = version of RangeClause. This is called with a list of
4858 Parse::range_clause_expr(const Expression_list* vals,
4859 Range_clause* p_range_clause)
4861 go_assert(this->peek_token()->is_keyword(KEYWORD_RANGE));
4863 p_range_clause->found = true;
4865 go_assert(vals->size() >= 1);
4866 if (vals->size() > 2)
4867 error_at(this->location(), "too many variables for range clause");
4869 this->advance_token();
4870 p_range_clause->range = this->expression(PRECEDENCE_NORMAL, false, false,
4873 p_range_clause->index = vals->front();
4874 if (vals->size() == 1)
4875 p_range_clause->value = NULL;
4877 p_range_clause->value = vals->back();
4880 // Push a statement on the break stack.
4883 Parse::push_break_statement(Statement* enclosing, Label* label)
4885 if (this->break_stack_ == NULL)
4886 this->break_stack_ = new Bc_stack();
4887 this->break_stack_->push_back(std::make_pair(enclosing, label));
4890 // Push a statement on the continue stack.
4893 Parse::push_continue_statement(Statement* enclosing, Label* label)
4895 if (this->continue_stack_ == NULL)
4896 this->continue_stack_ = new Bc_stack();
4897 this->continue_stack_->push_back(std::make_pair(enclosing, label));
4900 // Pop the break stack.
4903 Parse::pop_break_statement()
4905 this->break_stack_->pop_back();
4908 // Pop the continue stack.
4911 Parse::pop_continue_statement()
4913 this->continue_stack_->pop_back();
4916 // Find a break or continue statement given a label name.
4919 Parse::find_bc_statement(const Bc_stack* bc_stack, const std::string& label)
4921 if (bc_stack == NULL)
4923 for (Bc_stack::const_reverse_iterator p = bc_stack->rbegin();
4924 p != bc_stack->rend();
4927 if (p->second != NULL && p->second->name() == label)
4929 p->second->set_is_used();
4936 // BreakStat = "break" [ identifier ] .
4941 go_assert(this->peek_token()->is_keyword(KEYWORD_BREAK));
4942 source_location location = this->location();
4944 const Token* token = this->advance_token();
4945 Statement* enclosing;
4946 if (!token->is_identifier())
4948 if (this->break_stack_ == NULL || this->break_stack_->empty())
4950 error_at(this->location(),
4951 "break statement not within for or switch or select");
4954 enclosing = this->break_stack_->back().first;
4958 enclosing = this->find_bc_statement(this->break_stack_,
4959 token->identifier());
4960 if (enclosing == NULL)
4962 // If there is a label with this name, mark it as used to
4963 // avoid a useless error about an unused label.
4964 this->gogo_->add_label_reference(token->identifier(), 0, false);
4966 error_at(token->location(), "invalid break label %qs",
4967 Gogo::message_name(token->identifier()).c_str());
4968 this->advance_token();
4971 this->advance_token();
4974 Unnamed_label* label;
4975 if (enclosing->classification() == Statement::STATEMENT_FOR)
4976 label = enclosing->for_statement()->break_label();
4977 else if (enclosing->classification() == Statement::STATEMENT_FOR_RANGE)
4978 label = enclosing->for_range_statement()->break_label();
4979 else if (enclosing->classification() == Statement::STATEMENT_SWITCH)
4980 label = enclosing->switch_statement()->break_label();
4981 else if (enclosing->classification() == Statement::STATEMENT_TYPE_SWITCH)
4982 label = enclosing->type_switch_statement()->break_label();
4983 else if (enclosing->classification() == Statement::STATEMENT_SELECT)
4984 label = enclosing->select_statement()->break_label();
4988 this->gogo_->add_statement(Statement::make_break_statement(label,
4992 // ContinueStat = "continue" [ identifier ] .
4995 Parse::continue_stat()
4997 go_assert(this->peek_token()->is_keyword(KEYWORD_CONTINUE));
4998 source_location location = this->location();
5000 const Token* token = this->advance_token();
5001 Statement* enclosing;
5002 if (!token->is_identifier())
5004 if (this->continue_stack_ == NULL || this->continue_stack_->empty())
5006 error_at(this->location(), "continue statement not within for");
5009 enclosing = this->continue_stack_->back().first;
5013 enclosing = this->find_bc_statement(this->continue_stack_,
5014 token->identifier());
5015 if (enclosing == NULL)
5017 // If there is a label with this name, mark it as used to
5018 // avoid a useless error about an unused label.
5019 this->gogo_->add_label_reference(token->identifier(), 0, false);
5021 error_at(token->location(), "invalid continue label %qs",
5022 Gogo::message_name(token->identifier()).c_str());
5023 this->advance_token();
5026 this->advance_token();
5029 Unnamed_label* label;
5030 if (enclosing->classification() == Statement::STATEMENT_FOR)
5031 label = enclosing->for_statement()->continue_label();
5032 else if (enclosing->classification() == Statement::STATEMENT_FOR_RANGE)
5033 label = enclosing->for_range_statement()->continue_label();
5037 this->gogo_->add_statement(Statement::make_continue_statement(label,
5041 // GotoStat = "goto" identifier .
5046 go_assert(this->peek_token()->is_keyword(KEYWORD_GOTO));
5047 source_location location = this->location();
5048 const Token* token = this->advance_token();
5049 if (!token->is_identifier())
5050 error_at(this->location(), "expected label for goto");
5053 Label* label = this->gogo_->add_label_reference(token->identifier(),
5055 Statement* s = Statement::make_goto_statement(label, location);
5056 this->gogo_->add_statement(s);
5057 this->advance_token();
5061 // PackageClause = "package" PackageName .
5064 Parse::package_clause()
5066 const Token* token = this->peek_token();
5067 source_location location = token->location();
5069 if (!token->is_keyword(KEYWORD_PACKAGE))
5071 error_at(this->location(), "program must start with package clause");
5076 token = this->advance_token();
5077 if (token->is_identifier())
5079 name = token->identifier();
5082 error_at(this->location(), "invalid package name _");
5085 this->advance_token();
5089 error_at(this->location(), "package name must be an identifier");
5093 this->gogo_->set_package_name(name, location);
5096 // ImportDecl = "import" Decl<ImportSpec> .
5099 Parse::import_decl()
5101 go_assert(this->peek_token()->is_keyword(KEYWORD_IMPORT));
5102 this->advance_token();
5103 this->decl(&Parse::import_spec, NULL);
5106 // ImportSpec = [ "." | PackageName ] PackageFileName .
5109 Parse::import_spec(void*)
5111 const Token* token = this->peek_token();
5112 source_location location = token->location();
5114 std::string local_name;
5115 bool is_local_name_exported = false;
5116 if (token->is_op(OPERATOR_DOT))
5119 token = this->advance_token();
5121 else if (token->is_identifier())
5123 local_name = token->identifier();
5124 is_local_name_exported = token->is_identifier_exported();
5125 token = this->advance_token();
5128 if (!token->is_string())
5130 error_at(this->location(), "missing import package name");
5134 this->gogo_->import_package(token->string_value(), local_name,
5135 is_local_name_exported, location);
5137 this->advance_token();
5140 // SourceFile = PackageClause ";" { ImportDecl ";" }
5141 // { TopLevelDecl ";" } .
5146 this->package_clause();
5148 const Token* token = this->peek_token();
5149 if (token->is_op(OPERATOR_SEMICOLON))
5150 token = this->advance_token();
5152 error_at(this->location(),
5153 "expected %<;%> or newline after package clause");
5155 while (token->is_keyword(KEYWORD_IMPORT))
5157 this->import_decl();
5158 token = this->peek_token();
5159 if (token->is_op(OPERATOR_SEMICOLON))
5160 token = this->advance_token();
5162 error_at(this->location(),
5163 "expected %<;%> or newline after import declaration");
5166 while (!token->is_eof())
5168 if (this->declaration_may_start_here())
5169 this->declaration();
5172 error_at(this->location(), "expected declaration");
5174 this->advance_token();
5175 while (!this->peek_token()->is_eof()
5176 && !this->peek_token()->is_op(OPERATOR_SEMICOLON)
5177 && !this->peek_token()->is_op(OPERATOR_RCURLY));
5178 if (!this->peek_token()->is_eof()
5179 && !this->peek_token()->is_op(OPERATOR_SEMICOLON))
5180 this->advance_token();
5182 token = this->peek_token();
5183 if (token->is_op(OPERATOR_SEMICOLON))
5184 token = this->advance_token();
5185 else if (!token->is_eof() || !saw_errors())
5187 if (token->is_op(OPERATOR_CHANOP))
5188 error_at(this->location(),
5189 ("send statement used as value; "
5190 "use select for non-blocking send"));
5192 error_at(this->location(),
5193 "expected %<;%> or newline after top level declaration");
5194 this->skip_past_error(OPERATOR_INVALID);
5199 // Reset the current iota value.
5207 // Return the current iota value.
5215 // Increment the current iota value.
5218 Parse::increment_iota()
5223 // Skip forward to a semicolon or OP. OP will normally be
5224 // OPERATOR_RPAREN or OPERATOR_RCURLY. If we find a semicolon, move
5225 // past it and return. If we find OP, it will be the next token to
5226 // read. Return true if we are OK, false if we found EOF.
5229 Parse::skip_past_error(Operator op)
5231 const Token* token = this->peek_token();
5232 while (!token->is_op(op))
5234 if (token->is_eof())
5236 if (token->is_op(OPERATOR_SEMICOLON))
5238 this->advance_token();
5241 token = this->advance_token();
5246 // Check that an expression is not a sink.
5249 Parse::verify_not_sink(Expression* expr)
5251 if (expr->is_sink_expression())
5253 error_at(expr->location(), "cannot use _ as value");
5254 expr = Expression::make_error(expr->location());