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),
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 gcc_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)
341 named_object = this->gogo_->add_unknown_name(name, location);
343 else if (named_object->is_type())
345 if (!named_object->type_value()->is_visible())
348 else if (named_object->is_unknown() || named_object->is_type_declaration())
356 error_at(location, "expected type");
357 return Type::make_error_type();
360 if (named_object->is_type())
361 return named_object->type_value();
362 else if (named_object->is_unknown() || named_object->is_type_declaration())
363 return Type::make_forward_declaration(named_object);
368 // ArrayType = "[" [ ArrayLength ] "]" ElementType .
369 // ArrayLength = Expression .
370 // ElementType = CompleteType .
373 Parse::array_type(bool may_use_ellipsis)
375 gcc_assert(this->peek_token()->is_op(OPERATOR_LSQUARE));
376 const Token* token = this->advance_token();
378 Expression* length = NULL;
379 if (token->is_op(OPERATOR_RSQUARE))
380 this->advance_token();
383 if (!token->is_op(OPERATOR_ELLIPSIS))
384 length = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
385 else if (may_use_ellipsis)
387 // An ellipsis is used in composite literals to represent a
388 // fixed array of the size of the number of elements. We
389 // use a length of nil to represent this, and change the
390 // length when parsing the composite literal.
391 length = Expression::make_nil(this->location());
392 this->advance_token();
396 error_at(this->location(),
397 "use of %<[...]%> outside of array literal");
398 length = Expression::make_error(this->location());
399 this->advance_token();
401 if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
403 error_at(this->location(), "expected %<]%>");
404 return Type::make_error_type();
406 this->advance_token();
409 Type* element_type = this->type();
411 return Type::make_array_type(element_type, length);
414 // MapType = "map" "[" KeyType "]" ValueType .
415 // KeyType = CompleteType .
416 // ValueType = CompleteType .
421 source_location location = this->location();
422 gcc_assert(this->peek_token()->is_keyword(KEYWORD_MAP));
423 if (!this->advance_token()->is_op(OPERATOR_LSQUARE))
425 error_at(this->location(), "expected %<[%>");
426 return Type::make_error_type();
428 this->advance_token();
430 Type* key_type = this->type();
432 if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
434 error_at(this->location(), "expected %<]%>");
435 return Type::make_error_type();
437 this->advance_token();
439 Type* value_type = this->type();
441 if (key_type->is_error_type() || value_type->is_error_type())
442 return Type::make_error_type();
444 return Type::make_map_type(key_type, value_type, location);
447 // StructType = "struct" "{" { FieldDecl ";" } "}" .
452 gcc_assert(this->peek_token()->is_keyword(KEYWORD_STRUCT));
453 source_location location = this->location();
454 if (!this->advance_token()->is_op(OPERATOR_LCURLY))
456 source_location token_loc = this->location();
457 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
458 && this->advance_token()->is_op(OPERATOR_LCURLY))
459 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
462 error_at(this->location(), "expected %<{%>");
463 return Type::make_error_type();
466 this->advance_token();
468 Struct_field_list* sfl = new Struct_field_list;
469 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
471 this->field_decl(sfl);
472 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
473 this->advance_token();
474 else if (!this->peek_token()->is_op(OPERATOR_RCURLY))
476 error_at(this->location(), "expected %<;%> or %<}%> or newline");
477 if (!this->skip_past_error(OPERATOR_RCURLY))
478 return Type::make_error_type();
481 this->advance_token();
483 for (Struct_field_list::const_iterator pi = sfl->begin();
487 if (pi->type()->is_error_type())
489 for (Struct_field_list::const_iterator pj = pi + 1;
493 if (pi->field_name() == pj->field_name()
494 && !Gogo::is_sink_name(pi->field_name()))
495 error_at(pi->location(), "duplicate field name %<%s%>",
496 Gogo::message_name(pi->field_name()).c_str());
500 return Type::make_struct_type(sfl, location);
503 // FieldDecl = (IdentifierList CompleteType | TypeName) [ Tag ] .
504 // Tag = string_lit .
507 Parse::field_decl(Struct_field_list* sfl)
509 const Token* token = this->peek_token();
510 source_location location = token->location();
512 bool is_anonymous_pointer;
513 if (token->is_op(OPERATOR_MULT))
516 is_anonymous_pointer = true;
518 else if (token->is_identifier())
520 std::string id = token->identifier();
521 bool is_id_exported = token->is_identifier_exported();
522 source_location id_location = token->location();
523 token = this->advance_token();
524 is_anonymous = (token->is_op(OPERATOR_SEMICOLON)
525 || token->is_op(OPERATOR_RCURLY)
526 || token->is_op(OPERATOR_DOT)
527 || token->is_string());
528 is_anonymous_pointer = false;
529 this->unget_token(Token::make_identifier_token(id, is_id_exported,
534 error_at(this->location(), "expected field name");
535 while (!token->is_op(OPERATOR_SEMICOLON)
536 && !token->is_op(OPERATOR_RCURLY)
538 token = this->advance_token();
544 if (is_anonymous_pointer)
546 this->advance_token();
547 if (!this->peek_token()->is_identifier())
549 error_at(this->location(), "expected field name");
550 while (!token->is_op(OPERATOR_SEMICOLON)
551 && !token->is_op(OPERATOR_RCURLY)
553 token = this->advance_token();
557 Type* type = this->type_name(true);
560 if (this->peek_token()->is_string())
562 tag = this->peek_token()->string_value();
563 this->advance_token();
566 if (!type->is_error_type())
568 if (is_anonymous_pointer)
569 type = Type::make_pointer_type(type);
570 sfl->push_back(Struct_field(Typed_identifier("", type, location)));
572 sfl->back().set_tag(tag);
577 Typed_identifier_list til;
580 token = this->peek_token();
581 if (!token->is_identifier())
583 error_at(this->location(), "expected identifier");
587 this->gogo_->pack_hidden_name(token->identifier(),
588 token->is_identifier_exported());
589 til.push_back(Typed_identifier(name, NULL, token->location()));
590 if (!this->advance_token()->is_op(OPERATOR_COMMA))
592 this->advance_token();
595 Type* type = this->type();
598 if (this->peek_token()->is_string())
600 tag = this->peek_token()->string_value();
601 this->advance_token();
604 for (Typed_identifier_list::iterator p = til.begin();
609 sfl->push_back(Struct_field(*p));
611 sfl->back().set_tag(tag);
616 // PointerType = "*" Type .
619 Parse::pointer_type()
621 gcc_assert(this->peek_token()->is_op(OPERATOR_MULT));
622 this->advance_token();
623 Type* type = this->type();
624 if (type->is_error_type())
626 return Type::make_pointer_type(type);
629 // ChannelType = Channel | SendChannel | RecvChannel .
630 // Channel = "chan" ElementType .
631 // SendChannel = "chan" "<-" ElementType .
632 // RecvChannel = "<-" "chan" ElementType .
635 Parse::channel_type()
637 const Token* token = this->peek_token();
640 if (token->is_op(OPERATOR_CHANOP))
642 if (!this->advance_token()->is_keyword(KEYWORD_CHAN))
644 error_at(this->location(), "expected %<chan%>");
645 return Type::make_error_type();
648 this->advance_token();
652 gcc_assert(token->is_keyword(KEYWORD_CHAN));
653 if (this->advance_token()->is_op(OPERATOR_CHANOP))
656 this->advance_token();
659 Type* element_type = this->type();
660 return Type::make_channel_type(send, receive, element_type);
663 // Signature = Parameters [ Result ] .
665 // RECEIVER is the receiver if there is one, or NULL. LOCATION is the
666 // location of the start of the type.
668 // This returns NULL on a parse error.
671 Parse::signature(Typed_identifier* receiver, source_location location)
673 bool is_varargs = false;
674 Typed_identifier_list* params;
675 bool params_ok = this->parameters(¶ms, &is_varargs);
677 Typed_identifier_list* result = NULL;
678 if (this->peek_token()->is_op(OPERATOR_LPAREN)
679 || this->type_may_start_here())
681 if (!this->result(&result))
688 Function_type* ret = Type::make_function_type(receiver, params, result,
691 ret->set_is_varargs();
695 // Parameters = "(" [ ParameterList [ "," ] ] ")" .
697 // This returns false on a parse error.
700 Parse::parameters(Typed_identifier_list** pparams, bool* is_varargs)
704 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
706 error_at(this->location(), "expected %<(%>");
710 Typed_identifier_list* params = NULL;
711 bool saw_error = false;
713 const Token* token = this->advance_token();
714 if (!token->is_op(OPERATOR_RPAREN))
716 params = this->parameter_list(is_varargs);
719 token = this->peek_token();
722 // The optional trailing comma is picked up in parameter_list.
724 if (!token->is_op(OPERATOR_RPAREN))
725 error_at(this->location(), "expected %<)%>");
727 this->advance_token();
736 // ParameterList = ParameterDecl { "," ParameterDecl } .
738 // This sets *IS_VARARGS if the list ends with an ellipsis.
739 // IS_VARARGS will be NULL if varargs are not permitted.
741 // We pick up an optional trailing comma.
743 // This returns NULL if some error is seen.
745 Typed_identifier_list*
746 Parse::parameter_list(bool* is_varargs)
748 source_location location = this->location();
749 Typed_identifier_list* ret = new Typed_identifier_list();
751 bool saw_error = false;
753 // If we see an identifier and then a comma, then we don't know
754 // whether we are looking at a list of identifiers followed by a
755 // type, or a list of types given by name. We have to do an
756 // arbitrary lookahead to figure it out.
758 bool parameters_have_names;
759 const Token* token = this->peek_token();
760 if (!token->is_identifier())
762 // This must be a type which starts with something like '*'.
763 parameters_have_names = false;
767 std::string name = token->identifier();
768 bool is_exported = token->is_identifier_exported();
769 source_location location = token->location();
770 token = this->advance_token();
771 if (!token->is_op(OPERATOR_COMMA))
773 if (token->is_op(OPERATOR_DOT))
775 // This is a qualified identifier, which must turn out
777 parameters_have_names = false;
779 else if (token->is_op(OPERATOR_RPAREN))
781 // A single identifier followed by a parenthesis must be
783 parameters_have_names = false;
787 // An identifier followed by something other than a
788 // comma or a dot or a right parenthesis must be a
789 // parameter name followed by a type.
790 parameters_have_names = true;
793 this->unget_token(Token::make_identifier_token(name, is_exported,
798 // An identifier followed by a comma may be the first in a
799 // list of parameter names followed by a type, or it may be
800 // the first in a list of types without parameter names. To
801 // find out we gather as many identifiers separated by
803 std::string id_name = this->gogo_->pack_hidden_name(name,
805 ret->push_back(Typed_identifier(id_name, NULL, location));
806 bool just_saw_comma = true;
807 while (this->advance_token()->is_identifier())
809 name = this->peek_token()->identifier();
810 is_exported = this->peek_token()->is_identifier_exported();
811 location = this->peek_token()->location();
812 id_name = this->gogo_->pack_hidden_name(name, is_exported);
813 ret->push_back(Typed_identifier(id_name, NULL, location));
814 if (!this->advance_token()->is_op(OPERATOR_COMMA))
816 just_saw_comma = false;
823 // We saw ID1 "," ID2 "," followed by something which
824 // was not an identifier. We must be seeing the start
825 // of a type, and ID1 and ID2 must be types, and the
826 // parameters don't have names.
827 parameters_have_names = false;
829 else if (this->peek_token()->is_op(OPERATOR_RPAREN))
831 // We saw ID1 "," ID2 ")". ID1 and ID2 must be types,
832 // and the parameters don't have names.
833 parameters_have_names = false;
835 else if (this->peek_token()->is_op(OPERATOR_DOT))
837 // We saw ID1 "," ID2 ".". ID2 must be a package name,
838 // ID1 must be a type, and the parameters don't have
840 parameters_have_names = false;
841 this->unget_token(Token::make_identifier_token(name, is_exported,
844 just_saw_comma = true;
848 // We saw ID1 "," ID2 followed by something other than
849 // ",", ".", or ")". We must be looking at the start of
850 // a type, and ID1 and ID2 must be parameter names.
851 parameters_have_names = true;
854 if (parameters_have_names)
856 gcc_assert(!just_saw_comma);
857 // We have just seen ID1, ID2 xxx.
859 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
863 error_at(this->location(), "%<...%> only permits one name");
865 this->advance_token();
868 for (size_t i = 0; i < ret->size(); ++i)
869 ret->set_type(i, type);
870 if (!this->peek_token()->is_op(OPERATOR_COMMA))
871 return saw_error ? NULL : ret;
872 if (this->advance_token()->is_op(OPERATOR_RPAREN))
873 return saw_error ? NULL : ret;
877 Typed_identifier_list* tret = new Typed_identifier_list();
878 for (Typed_identifier_list::const_iterator p = ret->begin();
882 Named_object* no = this->gogo_->lookup(p->name(), NULL);
885 no = this->gogo_->add_unknown_name(p->name(),
889 type = no->type_value();
890 else if (no->is_unknown() || no->is_type_declaration())
891 type = Type::make_forward_declaration(no);
894 error_at(p->location(), "expected %<%s%> to be a type",
895 Gogo::message_name(p->name()).c_str());
897 type = Type::make_error_type();
899 tret->push_back(Typed_identifier("", type, p->location()));
904 || this->peek_token()->is_op(OPERATOR_RPAREN))
905 return saw_error ? NULL : ret;
910 bool mix_error = false;
911 this->parameter_decl(parameters_have_names, ret, is_varargs, &mix_error);
912 while (this->peek_token()->is_op(OPERATOR_COMMA))
914 if (is_varargs != NULL && *is_varargs)
916 error_at(this->location(), "%<...%> must be last parameter");
919 if (this->advance_token()->is_op(OPERATOR_RPAREN))
921 this->parameter_decl(parameters_have_names, ret, is_varargs, &mix_error);
925 error_at(location, "invalid named/anonymous mix");
936 // ParameterDecl = [ IdentifierList ] [ "..." ] Type .
939 Parse::parameter_decl(bool parameters_have_names,
940 Typed_identifier_list* til,
944 if (!parameters_have_names)
947 source_location location = this->location();
948 if (!this->peek_token()->is_identifier())
950 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
954 if (is_varargs == NULL)
955 error_at(this->location(), "invalid use of %<...%>");
958 this->advance_token();
959 if (is_varargs == NULL
960 && this->peek_token()->is_op(OPERATOR_RPAREN))
961 type = Type::make_error_type();
964 Type* element_type = this->type();
965 type = Type::make_array_type(element_type, NULL);
971 type = this->type_name(false);
972 if (type->is_error_type()
973 || (!this->peek_token()->is_op(OPERATOR_COMMA)
974 && !this->peek_token()->is_op(OPERATOR_RPAREN)))
977 while (!this->peek_token()->is_op(OPERATOR_COMMA)
978 && !this->peek_token()->is_op(OPERATOR_RPAREN))
979 this->advance_token();
982 if (!type->is_error_type())
983 til->push_back(Typed_identifier("", type, location));
987 size_t orig_count = til->size();
988 if (this->peek_token()->is_identifier())
989 this->identifier_list(til);
992 size_t new_count = til->size();
995 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
999 if (is_varargs == NULL)
1000 error_at(this->location(), "invalid use of %<...%>");
1001 else if (new_count > orig_count + 1)
1002 error_at(this->location(), "%<...%> only permits one name");
1005 this->advance_token();
1006 Type* element_type = this->type();
1007 type = Type::make_array_type(element_type, NULL);
1009 for (size_t i = orig_count; i < new_count; ++i)
1010 til->set_type(i, type);
1014 // Result = Parameters | Type .
1016 // This returns false on a parse error.
1019 Parse::result(Typed_identifier_list** presults)
1021 if (this->peek_token()->is_op(OPERATOR_LPAREN))
1022 return this->parameters(presults, NULL);
1025 source_location location = this->location();
1026 Type* type = this->type();
1027 if (type->is_error_type())
1032 Typed_identifier_list* til = new Typed_identifier_list();
1033 til->push_back(Typed_identifier("", type, location));
1039 // Block = "{" [ StatementList ] "}" .
1041 // Returns the location of the closing brace.
1046 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
1048 source_location loc = this->location();
1049 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1050 && this->advance_token()->is_op(OPERATOR_LCURLY))
1051 error_at(loc, "unexpected semicolon or newline before %<{%>");
1054 error_at(this->location(), "expected %<{%>");
1055 return UNKNOWN_LOCATION;
1059 const Token* token = this->advance_token();
1061 if (!token->is_op(OPERATOR_RCURLY))
1063 this->statement_list();
1064 token = this->peek_token();
1065 if (!token->is_op(OPERATOR_RCURLY))
1067 if (!token->is_eof() || !saw_errors())
1068 error_at(this->location(), "expected %<}%>");
1070 // Skip ahead to the end of the block, in hopes of avoiding
1071 // lots of meaningless errors.
1072 source_location ret = token->location();
1074 while (!token->is_eof())
1076 if (token->is_op(OPERATOR_LCURLY))
1078 else if (token->is_op(OPERATOR_RCURLY))
1083 this->advance_token();
1087 token = this->advance_token();
1088 ret = token->location();
1094 source_location ret = token->location();
1095 this->advance_token();
1099 // InterfaceType = "interface" "{" [ MethodSpecList ] "}" .
1100 // MethodSpecList = MethodSpec { ";" MethodSpec } [ ";" ] .
1103 Parse::interface_type()
1105 gcc_assert(this->peek_token()->is_keyword(KEYWORD_INTERFACE));
1106 source_location location = this->location();
1108 if (!this->advance_token()->is_op(OPERATOR_LCURLY))
1110 source_location token_loc = this->location();
1111 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1112 && this->advance_token()->is_op(OPERATOR_LCURLY))
1113 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
1116 error_at(this->location(), "expected %<{%>");
1117 return Type::make_error_type();
1120 this->advance_token();
1122 Typed_identifier_list* methods = new Typed_identifier_list();
1123 if (!this->peek_token()->is_op(OPERATOR_RCURLY))
1125 this->method_spec(methods);
1126 while (this->peek_token()->is_op(OPERATOR_SEMICOLON))
1128 if (this->advance_token()->is_op(OPERATOR_RCURLY))
1130 this->method_spec(methods);
1132 if (!this->peek_token()->is_op(OPERATOR_RCURLY))
1134 error_at(this->location(), "expected %<}%>");
1135 while (!this->advance_token()->is_op(OPERATOR_RCURLY))
1137 if (this->peek_token()->is_eof())
1138 return Type::make_error_type();
1142 this->advance_token();
1144 if (methods->empty())
1150 Interface_type* ret = Type::make_interface_type(methods, location);
1151 this->gogo_->record_interface_type(ret);
1155 // MethodSpec = MethodName Signature | InterfaceTypeName .
1156 // MethodName = identifier .
1157 // InterfaceTypeName = TypeName .
1160 Parse::method_spec(Typed_identifier_list* methods)
1162 const Token* token = this->peek_token();
1163 if (!token->is_identifier())
1165 error_at(this->location(), "expected identifier");
1169 std::string name = token->identifier();
1170 bool is_exported = token->is_identifier_exported();
1171 source_location location = token->location();
1173 if (this->advance_token()->is_op(OPERATOR_LPAREN))
1175 // This is a MethodName.
1176 name = this->gogo_->pack_hidden_name(name, is_exported);
1177 Type* type = this->signature(NULL, location);
1180 methods->push_back(Typed_identifier(name, type, location));
1184 this->unget_token(Token::make_identifier_token(name, is_exported,
1186 Type* type = this->type_name(false);
1187 if (type->is_error_type()
1188 || (!this->peek_token()->is_op(OPERATOR_SEMICOLON)
1189 && !this->peek_token()->is_op(OPERATOR_RCURLY)))
1191 if (this->peek_token()->is_op(OPERATOR_COMMA))
1192 error_at(this->location(),
1193 "name list not allowed in interface type");
1195 error_at(location, "expected signature or type name");
1196 token = this->peek_token();
1197 while (!token->is_eof()
1198 && !token->is_op(OPERATOR_SEMICOLON)
1199 && !token->is_op(OPERATOR_RCURLY))
1200 token = this->advance_token();
1203 // This must be an interface type, but we can't check that now.
1204 // We check it and pull out the methods in
1205 // Interface_type::do_verify.
1206 methods->push_back(Typed_identifier("", type, location));
1210 // Declaration = ConstDecl | TypeDecl | VarDecl | FunctionDecl | MethodDecl .
1213 Parse::declaration()
1215 const Token* token = this->peek_token();
1216 if (token->is_keyword(KEYWORD_CONST))
1218 else if (token->is_keyword(KEYWORD_TYPE))
1220 else if (token->is_keyword(KEYWORD_VAR))
1222 else if (token->is_keyword(KEYWORD_FUNC))
1223 this->function_decl();
1226 error_at(this->location(), "expected declaration");
1227 this->advance_token();
1232 Parse::declaration_may_start_here()
1234 const Token* token = this->peek_token();
1235 return (token->is_keyword(KEYWORD_CONST)
1236 || token->is_keyword(KEYWORD_TYPE)
1237 || token->is_keyword(KEYWORD_VAR)
1238 || token->is_keyword(KEYWORD_FUNC));
1241 // Decl<P> = P | "(" [ List<P> ] ")" .
1244 Parse::decl(void (Parse::*pfn)(void*), void* varg)
1246 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
1250 if (!this->advance_token()->is_op(OPERATOR_RPAREN))
1252 this->list(pfn, varg, true);
1253 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
1255 error_at(this->location(), "missing %<)%>");
1256 while (!this->advance_token()->is_op(OPERATOR_RPAREN))
1258 if (this->peek_token()->is_eof())
1263 this->advance_token();
1267 // List<P> = P { ";" P } [ ";" ] .
1269 // In order to pick up the trailing semicolon we need to know what
1270 // might follow. This is either a '}' or a ')'.
1273 Parse::list(void (Parse::*pfn)(void*), void* varg, bool follow_is_paren)
1276 Operator follow = follow_is_paren ? OPERATOR_RPAREN : OPERATOR_RCURLY;
1277 while (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1278 || this->peek_token()->is_op(OPERATOR_COMMA))
1280 if (this->peek_token()->is_op(OPERATOR_COMMA))
1281 error_at(this->location(), "unexpected comma");
1282 if (this->advance_token()->is_op(follow))
1288 // ConstDecl = "const" ( ConstSpec | "(" { ConstSpec ";" } ")" ) .
1293 gcc_assert(this->peek_token()->is_keyword(KEYWORD_CONST));
1294 this->advance_token();
1297 Type* last_type = NULL;
1298 Expression_list* last_expr_list = NULL;
1300 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
1301 this->const_spec(&last_type, &last_expr_list);
1304 this->advance_token();
1305 while (!this->peek_token()->is_op(OPERATOR_RPAREN))
1307 this->const_spec(&last_type, &last_expr_list);
1308 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
1309 this->advance_token();
1310 else if (!this->peek_token()->is_op(OPERATOR_RPAREN))
1312 error_at(this->location(), "expected %<;%> or %<)%> or newline");
1313 if (!this->skip_past_error(OPERATOR_RPAREN))
1317 this->advance_token();
1320 if (last_expr_list != NULL)
1321 delete last_expr_list;
1324 // ConstSpec = IdentifierList [ [ CompleteType ] "=" ExpressionList ] .
1327 Parse::const_spec(Type** last_type, Expression_list** last_expr_list)
1329 Typed_identifier_list til;
1330 this->identifier_list(&til);
1333 if (this->type_may_start_here())
1335 type = this->type();
1337 *last_expr_list = NULL;
1340 Expression_list *expr_list;
1341 if (!this->peek_token()->is_op(OPERATOR_EQ))
1343 if (*last_expr_list == NULL)
1345 error_at(this->location(), "expected %<=%>");
1349 expr_list = new Expression_list;
1350 for (Expression_list::const_iterator p = (*last_expr_list)->begin();
1351 p != (*last_expr_list)->end();
1353 expr_list->push_back((*p)->copy());
1357 this->advance_token();
1358 expr_list = this->expression_list(NULL, false);
1360 if (*last_expr_list != NULL)
1361 delete *last_expr_list;
1362 *last_expr_list = expr_list;
1365 Expression_list::const_iterator pe = expr_list->begin();
1366 for (Typed_identifier_list::iterator pi = til.begin();
1370 if (pe == expr_list->end())
1372 error_at(this->location(), "not enough initializers");
1378 if (!Gogo::is_sink_name(pi->name()))
1379 this->gogo_->add_constant(*pi, *pe, this->iota_value());
1381 if (pe != expr_list->end())
1382 error_at(this->location(), "too many initializers");
1384 this->increment_iota();
1389 // TypeDecl = "type" Decl<TypeSpec> .
1394 gcc_assert(this->peek_token()->is_keyword(KEYWORD_TYPE));
1395 this->advance_token();
1396 this->decl(&Parse::type_spec, NULL);
1399 // TypeSpec = identifier Type .
1402 Parse::type_spec(void*)
1404 const Token* token = this->peek_token();
1405 if (!token->is_identifier())
1407 error_at(this->location(), "expected identifier");
1410 std::string name = token->identifier();
1411 bool is_exported = token->is_identifier_exported();
1412 source_location location = token->location();
1413 token = this->advance_token();
1415 // The scope of the type name starts at the point where the
1416 // identifier appears in the source code. We implement this by
1417 // declaring the type before we read the type definition.
1418 Named_object* named_type = NULL;
1421 name = this->gogo_->pack_hidden_name(name, is_exported);
1422 named_type = this->gogo_->declare_type(name, location);
1426 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
1427 type = this->type();
1430 error_at(this->location(),
1431 "unexpected semicolon or newline in type declaration");
1432 type = Type::make_error_type();
1433 this->advance_token();
1436 if (type->is_error_type())
1438 while (!this->peek_token()->is_op(OPERATOR_SEMICOLON)
1439 && !this->peek_token()->is_eof())
1440 this->advance_token();
1445 if (named_type->is_type_declaration())
1447 Type* ftype = type->forwarded();
1448 if (ftype->forward_declaration_type() != NULL
1449 && (ftype->forward_declaration_type()->named_object()
1452 error_at(location, "invalid recursive type");
1453 type = Type::make_error_type();
1456 this->gogo_->define_type(named_type,
1457 Type::make_named_type(named_type, type,
1459 gcc_assert(named_type->package() == NULL);
1463 // This will probably give a redefinition error.
1464 this->gogo_->add_type(name, type, location);
1469 // VarDecl = "var" Decl<VarSpec> .
1474 gcc_assert(this->peek_token()->is_keyword(KEYWORD_VAR));
1475 this->advance_token();
1476 this->decl(&Parse::var_spec, NULL);
1479 // VarSpec = IdentifierList
1480 // ( CompleteType [ "=" ExpressionList ] | "=" ExpressionList ) .
1483 Parse::var_spec(void*)
1485 // Get the variable names.
1486 Typed_identifier_list til;
1487 this->identifier_list(&til);
1489 source_location location = this->location();
1492 Expression_list* init = NULL;
1493 if (!this->peek_token()->is_op(OPERATOR_EQ))
1495 type = this->type();
1496 if (type->is_error_type())
1498 while (!this->peek_token()->is_op(OPERATOR_EQ)
1499 && !this->peek_token()->is_op(OPERATOR_SEMICOLON)
1500 && !this->peek_token()->is_eof())
1501 this->advance_token();
1503 if (this->peek_token()->is_op(OPERATOR_EQ))
1505 this->advance_token();
1506 init = this->expression_list(NULL, false);
1511 this->advance_token();
1512 init = this->expression_list(NULL, false);
1515 this->init_vars(&til, type, init, false, location);
1521 // Create variables. TIL is a list of variable names. If TYPE is not
1522 // NULL, it is the type of all the variables. If INIT is not NULL, it
1523 // is an initializer list for the variables.
1526 Parse::init_vars(const Typed_identifier_list* til, Type* type,
1527 Expression_list* init, bool is_coloneq,
1528 source_location location)
1530 // Check for an initialization which can yield multiple values.
1531 if (init != NULL && init->size() == 1 && til->size() > 1)
1533 if (this->init_vars_from_call(til, type, *init->begin(), is_coloneq,
1536 if (this->init_vars_from_map(til, type, *init->begin(), is_coloneq,
1539 if (this->init_vars_from_receive(til, type, *init->begin(), is_coloneq,
1542 if (this->init_vars_from_type_guard(til, type, *init->begin(),
1543 is_coloneq, location))
1547 if (init != NULL && init->size() != til->size())
1549 if (init->empty() || !init->front()->is_error_expression())
1550 error_at(location, "wrong number of initializations");
1553 type = Type::make_error_type();
1556 // Note that INIT was already parsed with the old name bindings, so
1557 // we don't have to worry that it will accidentally refer to the
1558 // newly declared variables.
1560 Expression_list::const_iterator pexpr;
1562 pexpr = init->begin();
1563 bool any_new = false;
1564 for (Typed_identifier_list::const_iterator p = til->begin();
1569 gcc_assert(pexpr != init->end());
1570 this->init_var(*p, type, init == NULL ? NULL : *pexpr, is_coloneq,
1576 gcc_assert(pexpr == init->end());
1577 if (is_coloneq && !any_new)
1578 error_at(location, "variables redeclared but no variable is new");
1581 // See if we need to initialize a list of variables from a function
1582 // call. This returns true if we have set up the variables and the
1586 Parse::init_vars_from_call(const Typed_identifier_list* vars, Type* type,
1587 Expression* expr, bool is_coloneq,
1588 source_location location)
1590 Call_expression* call = expr->call_expression();
1594 // This is a function call. We can't check here whether it returns
1595 // the right number of values, but it might. Declare the variables,
1596 // and then assign the results of the call to them.
1598 unsigned int index = 0;
1599 bool any_new = false;
1600 for (Typed_identifier_list::const_iterator pv = vars->begin();
1604 Expression* init = Expression::make_call_result(call, index);
1605 this->init_var(*pv, type, init, is_coloneq, false, &any_new);
1608 if (is_coloneq && !any_new)
1609 error_at(location, "variables redeclared but no variable is new");
1614 // See if we need to initialize a pair of values from a map index
1615 // expression. This returns true if we have set up the variables and
1616 // the initialization.
1619 Parse::init_vars_from_map(const Typed_identifier_list* vars, Type* type,
1620 Expression* expr, bool is_coloneq,
1621 source_location location)
1623 Index_expression* index = expr->index_expression();
1626 if (vars->size() != 2)
1629 // This is an index which is being assigned to two variables. It
1630 // must be a map index. Declare the variables, and then assign the
1631 // results of the map index.
1632 bool any_new = false;
1633 Typed_identifier_list::const_iterator p = vars->begin();
1634 Expression* init = type == NULL ? index : NULL;
1635 Named_object* val_no = this->init_var(*p, type, init, is_coloneq,
1636 type == NULL, &any_new);
1637 if (type == NULL && any_new && val_no->is_variable())
1638 val_no->var_value()->set_type_from_init_tuple();
1639 Expression* val_var = Expression::make_var_reference(val_no, location);
1642 Type* var_type = type;
1643 if (var_type == NULL)
1644 var_type = Type::lookup_bool_type();
1645 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1647 Expression* present_var = Expression::make_var_reference(no, location);
1649 if (is_coloneq && !any_new)
1650 error_at(location, "variables redeclared but no variable is new");
1652 Statement* s = Statement::make_tuple_map_assignment(val_var, present_var,
1655 if (!this->gogo_->in_global_scope())
1656 this->gogo_->add_statement(s);
1657 else if (!val_no->is_sink())
1659 if (val_no->is_variable())
1660 val_no->var_value()->add_preinit_statement(s);
1662 else if (!no->is_sink())
1664 if (no->is_variable())
1665 no->var_value()->add_preinit_statement(s);
1669 // Execute the map index expression just so that we can fail if
1671 Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
1673 dummy->var_value()->add_preinit_statement(s);
1679 // See if we need to initialize a pair of values from a receive
1680 // expression. This returns true if we have set up the variables and
1681 // the initialization.
1684 Parse::init_vars_from_receive(const Typed_identifier_list* vars, Type* type,
1685 Expression* expr, bool is_coloneq,
1686 source_location location)
1688 Receive_expression* receive = expr->receive_expression();
1689 if (receive == NULL)
1691 if (vars->size() != 2)
1694 // This is a receive expression which is being assigned to two
1695 // variables. Declare the variables, and then assign the results of
1697 bool any_new = false;
1698 Typed_identifier_list::const_iterator p = vars->begin();
1699 Expression* init = type == NULL ? receive : NULL;
1700 Named_object* val_no = this->init_var(*p, type, init, is_coloneq,
1701 type == NULL, &any_new);
1702 if (type == NULL && any_new && val_no->is_variable())
1703 val_no->var_value()->set_type_from_init_tuple();
1704 Expression* val_var = Expression::make_var_reference(val_no, location);
1707 Type* var_type = type;
1708 if (var_type == NULL)
1709 var_type = Type::lookup_bool_type();
1710 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1712 Expression* received_var = Expression::make_var_reference(no, location);
1714 if (is_coloneq && !any_new)
1715 error_at(location, "variables redeclared but no variable is new");
1717 Statement* s = Statement::make_tuple_receive_assignment(val_var,
1722 if (!this->gogo_->in_global_scope())
1723 this->gogo_->add_statement(s);
1724 else if (!val_no->is_sink())
1726 if (val_no->is_variable())
1727 val_no->var_value()->add_preinit_statement(s);
1729 else if (!no->is_sink())
1731 if (no->is_variable())
1732 no->var_value()->add_preinit_statement(s);
1736 Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
1738 dummy->var_value()->add_preinit_statement(s);
1744 // See if we need to initialize a pair of values from a type guard
1745 // expression. This returns true if we have set up the variables and
1746 // the initialization.
1749 Parse::init_vars_from_type_guard(const Typed_identifier_list* vars,
1750 Type* type, Expression* expr,
1751 bool is_coloneq, source_location location)
1753 Type_guard_expression* type_guard = expr->type_guard_expression();
1754 if (type_guard == NULL)
1756 if (vars->size() != 2)
1759 // This is a type guard expression which is being assigned to two
1760 // variables. Declare the variables, and then assign the results of
1762 bool any_new = false;
1763 Typed_identifier_list::const_iterator p = vars->begin();
1764 Type* var_type = type;
1765 if (var_type == NULL)
1766 var_type = type_guard->type();
1767 Named_object* val_no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1769 Expression* val_var = Expression::make_var_reference(val_no, location);
1773 if (var_type == NULL)
1774 var_type = Type::lookup_bool_type();
1775 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1777 Expression* ok_var = Expression::make_var_reference(no, location);
1779 Expression* texpr = type_guard->expr();
1780 Type* t = type_guard->type();
1781 Statement* s = Statement::make_tuple_type_guard_assignment(val_var, ok_var,
1785 if (is_coloneq && !any_new)
1786 error_at(location, "variables redeclared but no variable is new");
1788 if (!this->gogo_->in_global_scope())
1789 this->gogo_->add_statement(s);
1790 else if (!val_no->is_sink())
1792 if (val_no->is_variable())
1793 val_no->var_value()->add_preinit_statement(s);
1795 else if (!no->is_sink())
1797 if (no->is_variable())
1798 no->var_value()->add_preinit_statement(s);
1802 Named_object* dummy = this->create_dummy_global(type, NULL, location);
1803 dummy->var_value()->add_preinit_statement(s);
1809 // Create a single variable. If IS_COLONEQ is true, we permit
1810 // redeclarations in the same block, and we set *IS_NEW when we find a
1811 // new variable which is not a redeclaration.
1814 Parse::init_var(const Typed_identifier& tid, Type* type, Expression* init,
1815 bool is_coloneq, bool type_from_init, bool* is_new)
1817 source_location location = tid.location();
1819 if (Gogo::is_sink_name(tid.name()))
1821 if (!type_from_init && init != NULL)
1823 if (!this->gogo_->in_global_scope())
1824 this->gogo_->add_statement(Statement::make_statement(init));
1826 return this->create_dummy_global(type, init, location);
1828 return this->gogo_->add_sink();
1833 Named_object* no = this->gogo_->lookup_in_block(tid.name());
1835 && (no->is_variable() || no->is_result_variable()))
1837 // INIT may be NULL even when IS_COLONEQ is true for cases
1838 // like v, ok := x.(int).
1839 if (!type_from_init && init != NULL)
1841 Expression *v = Expression::make_var_reference(no, location);
1842 Statement *s = Statement::make_assignment(v, init, location);
1843 this->gogo_->add_statement(s);
1849 Variable* var = new Variable(type, init, this->gogo_->in_global_scope(),
1850 false, false, location);
1851 return this->gogo_->add_variable(tid.name(), var);
1854 // Create a dummy global variable to force an initializer to be run in
1855 // the right place. This is used when a sink variable is initialized
1859 Parse::create_dummy_global(Type* type, Expression* init,
1860 source_location location)
1862 Variable* var = new Variable(type, init, true, false, false, location);
1865 snprintf(buf, sizeof buf, "_.%d", count);
1867 return this->gogo_->add_variable(buf, var);
1870 // SimpleVarDecl = identifier ":=" Expression .
1872 // We've already seen the identifier.
1874 // FIXME: We also have to implement
1875 // IdentifierList ":=" ExpressionList
1876 // In order to support both "a, b := 1, 0" and "a, b = 1, 0" we accept
1877 // tuple assignments here as well.
1879 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
1882 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
1883 // guard (var := expr.("type") using the literal keyword "type").
1886 Parse::simple_var_decl_or_assignment(const std::string& name,
1887 source_location location,
1888 Range_clause* p_range_clause,
1889 Type_switch* p_type_switch)
1891 Typed_identifier_list til;
1892 til.push_back(Typed_identifier(name, NULL, location));
1894 // We've seen one identifier. If we see a comma now, this could be
1896 if (this->peek_token()->is_op(OPERATOR_COMMA))
1898 gcc_assert(p_type_switch == NULL);
1901 const Token* token = this->advance_token();
1902 if (!token->is_identifier())
1905 std::string id = token->identifier();
1906 bool is_id_exported = token->is_identifier_exported();
1907 source_location id_location = token->location();
1909 token = this->advance_token();
1910 if (!token->is_op(OPERATOR_COMMA))
1912 if (token->is_op(OPERATOR_COLONEQ))
1914 id = this->gogo_->pack_hidden_name(id, is_id_exported);
1915 til.push_back(Typed_identifier(id, NULL, location));
1918 this->unget_token(Token::make_identifier_token(id,
1924 id = this->gogo_->pack_hidden_name(id, is_id_exported);
1925 til.push_back(Typed_identifier(id, NULL, location));
1928 // We have a comma separated list of identifiers in TIL. If the
1929 // next token is COLONEQ, then this is a simple var decl, and we
1930 // have the complete list of identifiers. If the next token is
1931 // not COLONEQ, then the only valid parse is a tuple assignment.
1932 // The list of identifiers we have so far is really a list of
1933 // expressions. There are more expressions following.
1935 if (!this->peek_token()->is_op(OPERATOR_COLONEQ))
1937 Expression_list* exprs = new Expression_list;
1938 for (Typed_identifier_list::const_iterator p = til.begin();
1941 exprs->push_back(this->id_to_expression(p->name(),
1944 Expression_list* more_exprs = this->expression_list(NULL, true);
1945 for (Expression_list::const_iterator p = more_exprs->begin();
1946 p != more_exprs->end();
1948 exprs->push_back(*p);
1951 this->tuple_assignment(exprs, p_range_clause);
1956 gcc_assert(this->peek_token()->is_op(OPERATOR_COLONEQ));
1957 const Token* token = this->advance_token();
1959 if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
1961 this->range_clause_decl(&til, p_range_clause);
1965 Expression_list* init;
1966 if (p_type_switch == NULL)
1967 init = this->expression_list(NULL, false);
1970 bool is_type_switch = false;
1971 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true,
1975 p_type_switch->found = true;
1976 p_type_switch->name = name;
1977 p_type_switch->location = location;
1978 p_type_switch->expr = expr;
1982 if (!this->peek_token()->is_op(OPERATOR_COMMA))
1984 init = new Expression_list();
1985 init->push_back(expr);
1989 this->advance_token();
1990 init = this->expression_list(expr, false);
1994 this->init_vars(&til, NULL, init, true, location);
1997 // FunctionDecl = "func" identifier Signature [ Block ] .
1998 // MethodDecl = "func" Receiver identifier Signature [ Block ] .
2001 // FunctionDecl = "func" identifier Signature
2002 // __asm__ "(" string_lit ")" .
2003 // This extension means a function whose real name is the identifier
2007 Parse::function_decl()
2009 gcc_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
2010 source_location location = this->location();
2011 const Token* token = this->advance_token();
2013 Typed_identifier* rec = NULL;
2014 if (token->is_op(OPERATOR_LPAREN))
2016 rec = this->receiver();
2017 token = this->peek_token();
2020 if (!token->is_identifier())
2022 error_at(this->location(), "expected function name");
2027 this->gogo_->pack_hidden_name(token->identifier(),
2028 token->is_identifier_exported());
2030 this->advance_token();
2032 Function_type* fntype = this->signature(rec, this->location());
2036 Named_object* named_object = NULL;
2038 if (this->peek_token()->is_keyword(KEYWORD_ASM))
2040 if (!this->advance_token()->is_op(OPERATOR_LPAREN))
2042 error_at(this->location(), "expected %<(%>");
2045 token = this->advance_token();
2046 if (!token->is_string())
2048 error_at(this->location(), "expected string");
2051 std::string asm_name = token->string_value();
2052 if (!this->advance_token()->is_op(OPERATOR_RPAREN))
2054 error_at(this->location(), "expected %<)%>");
2057 this->advance_token();
2058 named_object = this->gogo_->declare_function(name, fntype, location);
2059 if (named_object->is_function_declaration())
2060 named_object->func_declaration_value()->set_asm_name(asm_name);
2063 // Check for the easy error of a newline before the opening brace.
2064 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
2066 source_location semi_loc = this->location();
2067 if (this->advance_token()->is_op(OPERATOR_LCURLY))
2068 error_at(this->location(),
2069 "unexpected semicolon or newline before %<{%>");
2071 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
2075 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
2077 if (named_object == NULL)
2078 named_object = this->gogo_->declare_function(name, fntype, location);
2082 this->gogo_->start_function(name, fntype, true, location);
2083 source_location end_loc = this->block();
2084 this->gogo_->finish_function(end_loc);
2088 // Receiver = "(" [ identifier ] [ "*" ] BaseTypeName ")" .
2089 // BaseTypeName = identifier .
2094 gcc_assert(this->peek_token()->is_op(OPERATOR_LPAREN));
2097 const Token* token = this->advance_token();
2098 source_location location = token->location();
2099 if (!token->is_op(OPERATOR_MULT))
2101 if (!token->is_identifier())
2103 error_at(this->location(), "method has no receiver");
2104 while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
2105 token = this->advance_token();
2106 if (!token->is_eof())
2107 this->advance_token();
2110 name = token->identifier();
2111 bool is_exported = token->is_identifier_exported();
2112 token = this->advance_token();
2113 if (!token->is_op(OPERATOR_DOT) && !token->is_op(OPERATOR_RPAREN))
2115 // An identifier followed by something other than a dot or a
2116 // right parenthesis must be a receiver name followed by a
2118 name = this->gogo_->pack_hidden_name(name, is_exported);
2122 // This must be a type name.
2123 this->unget_token(Token::make_identifier_token(name, is_exported,
2125 token = this->peek_token();
2130 // Here the receiver name is in NAME (it is empty if the receiver is
2131 // unnamed) and TOKEN is the first token in the type.
2133 bool is_pointer = false;
2134 if (token->is_op(OPERATOR_MULT))
2137 token = this->advance_token();
2140 if (!token->is_identifier())
2142 error_at(this->location(), "expected receiver name or type");
2143 int c = token->is_op(OPERATOR_LPAREN) ? 1 : 0;
2144 while (!token->is_eof())
2146 token = this->advance_token();
2147 if (token->is_op(OPERATOR_LPAREN))
2149 else if (token->is_op(OPERATOR_RPAREN))
2156 if (!token->is_eof())
2157 this->advance_token();
2161 Type* type = this->type_name(true);
2163 if (is_pointer && !type->is_error_type())
2164 type = Type::make_pointer_type(type);
2166 if (this->peek_token()->is_op(OPERATOR_RPAREN))
2167 this->advance_token();
2170 if (this->peek_token()->is_op(OPERATOR_COMMA))
2171 error_at(this->location(), "method has multiple receivers");
2173 error_at(this->location(), "expected %<)%>");
2174 while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
2175 token = this->advance_token();
2176 if (!token->is_eof())
2177 this->advance_token();
2181 return new Typed_identifier(name, type, location);
2184 // Operand = Literal | QualifiedIdent | MethodExpr | "(" Expression ")" .
2185 // Literal = BasicLit | CompositeLit | FunctionLit .
2186 // BasicLit = int_lit | float_lit | imaginary_lit | char_lit | string_lit .
2188 // If MAY_BE_SINK is true, this operand may be "_".
2191 Parse::operand(bool may_be_sink)
2193 const Token* token = this->peek_token();
2195 switch (token->classification())
2197 case Token::TOKEN_IDENTIFIER:
2199 source_location location = token->location();
2200 std::string id = token->identifier();
2201 bool is_exported = token->is_identifier_exported();
2202 std::string packed = this->gogo_->pack_hidden_name(id, is_exported);
2204 Named_object* in_function;
2205 Named_object* named_object = this->gogo_->lookup(packed, &in_function);
2207 Package* package = NULL;
2208 if (named_object != NULL && named_object->is_package())
2210 if (!this->advance_token()->is_op(OPERATOR_DOT)
2211 || !this->advance_token()->is_identifier())
2213 error_at(location, "unexpected reference to package");
2214 return Expression::make_error(location);
2216 package = named_object->package_value();
2217 package->set_used();
2218 id = this->peek_token()->identifier();
2219 is_exported = this->peek_token()->is_identifier_exported();
2220 packed = this->gogo_->pack_hidden_name(id, is_exported);
2221 named_object = package->lookup(packed);
2222 location = this->location();
2223 gcc_assert(in_function == NULL);
2226 this->advance_token();
2228 if (named_object != NULL
2229 && named_object->is_type()
2230 && !named_object->type_value()->is_visible())
2232 gcc_assert(package != NULL);
2233 error_at(location, "invalid reference to hidden type %<%s.%s%>",
2234 Gogo::message_name(package->name()).c_str(),
2235 Gogo::message_name(id).c_str());
2236 return Expression::make_error(location);
2240 if (named_object == NULL)
2242 if (package != NULL)
2244 std::string n1 = Gogo::message_name(package->name());
2245 std::string n2 = Gogo::message_name(id);
2248 ("invalid reference to unexported identifier "
2250 n1.c_str(), n2.c_str());
2253 "reference to undefined identifier %<%s.%s%>",
2254 n1.c_str(), n2.c_str());
2255 return Expression::make_error(location);
2258 named_object = this->gogo_->add_unknown_name(packed, location);
2261 if (in_function != NULL
2262 && in_function != this->gogo_->current_function()
2263 && (named_object->is_variable()
2264 || named_object->is_result_variable()))
2265 return this->enclosing_var_reference(in_function, named_object,
2268 switch (named_object->classification())
2270 case Named_object::NAMED_OBJECT_CONST:
2271 return Expression::make_const_reference(named_object, location);
2272 case Named_object::NAMED_OBJECT_TYPE:
2273 return Expression::make_type(named_object->type_value(), location);
2274 case Named_object::NAMED_OBJECT_TYPE_DECLARATION:
2276 Type* t = Type::make_forward_declaration(named_object);
2277 return Expression::make_type(t, location);
2279 case Named_object::NAMED_OBJECT_VAR:
2280 case Named_object::NAMED_OBJECT_RESULT_VAR:
2281 return Expression::make_var_reference(named_object, location);
2282 case Named_object::NAMED_OBJECT_SINK:
2284 return Expression::make_sink(location);
2287 error_at(location, "cannot use _ as value");
2288 return Expression::make_error(location);
2290 case Named_object::NAMED_OBJECT_FUNC:
2291 case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
2292 return Expression::make_func_reference(named_object, NULL,
2294 case Named_object::NAMED_OBJECT_UNKNOWN:
2295 return Expression::make_unknown_reference(named_object, location);
2302 case Token::TOKEN_STRING:
2303 ret = Expression::make_string(token->string_value(), token->location());
2304 this->advance_token();
2307 case Token::TOKEN_INTEGER:
2308 ret = Expression::make_integer(token->integer_value(), NULL,
2310 this->advance_token();
2313 case Token::TOKEN_FLOAT:
2314 ret = Expression::make_float(token->float_value(), NULL,
2316 this->advance_token();
2319 case Token::TOKEN_IMAGINARY:
2322 mpfr_init_set_ui(zero, 0, GMP_RNDN);
2323 ret = Expression::make_complex(&zero, token->imaginary_value(),
2324 NULL, token->location());
2326 this->advance_token();
2330 case Token::TOKEN_KEYWORD:
2331 switch (token->keyword())
2334 return this->function_lit();
2336 case KEYWORD_INTERFACE:
2338 case KEYWORD_STRUCT:
2340 source_location location = token->location();
2341 return Expression::make_type(this->type(), location);
2348 case Token::TOKEN_OPERATOR:
2349 if (token->is_op(OPERATOR_LPAREN))
2351 this->advance_token();
2352 ret = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2353 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2354 error_at(this->location(), "missing %<)%>");
2356 this->advance_token();
2359 else if (token->is_op(OPERATOR_LSQUARE))
2361 // Here we call array_type directly, as this is the only
2362 // case where an ellipsis is permitted for an array type.
2363 source_location location = token->location();
2364 return Expression::make_type(this->array_type(true), location);
2372 error_at(this->location(), "expected operand");
2373 return Expression::make_error(this->location());
2376 // Handle a reference to a variable in an enclosing function. We add
2377 // it to a list of such variables. We return a reference to a field
2378 // in a struct which will be passed on the static chain when calling
2379 // the current function.
2382 Parse::enclosing_var_reference(Named_object* in_function, Named_object* var,
2383 source_location location)
2385 gcc_assert(var->is_variable() || var->is_result_variable());
2387 Named_object* this_function = this->gogo_->current_function();
2388 Named_object* closure = this_function->func_value()->closure_var();
2390 Enclosing_var ev(var, in_function, this->enclosing_vars_.size());
2391 std::pair<Enclosing_vars::iterator, bool> ins =
2392 this->enclosing_vars_.insert(ev);
2395 // This is a variable we have not seen before. Add a new field
2396 // to the closure type.
2397 this_function->func_value()->add_closure_field(var, location);
2400 Expression* closure_ref = Expression::make_var_reference(closure,
2402 closure_ref = Expression::make_unary(OPERATOR_MULT, closure_ref, location);
2404 // The closure structure holds pointers to the variables, so we need
2405 // to introduce an indirection.
2406 Expression* e = Expression::make_field_reference(closure_ref,
2409 e = Expression::make_unary(OPERATOR_MULT, e, location);
2413 // CompositeLit = LiteralType LiteralValue .
2414 // LiteralType = StructType | ArrayType | "[" "..." "]" ElementType |
2415 // SliceType | MapType | TypeName .
2416 // LiteralValue = "{" [ ElementList [ "," ] ] "}" .
2417 // ElementList = Element { "," Element } .
2418 // Element = [ Key ":" ] Value .
2419 // Key = Expression .
2420 // Value = Expression | LiteralValue .
2422 // We have already seen the type if there is one, and we are now
2423 // looking at the LiteralValue. The case "[" "..." "]" ElementType
2424 // will be seen here as an array type whose length is "nil". The
2425 // DEPTH parameter is non-zero if this is an embedded composite
2426 // literal and the type was omitted. It gives the number of steps up
2427 // to the type which was provided. E.g., in [][]int{{1}} it will be
2428 // 1. In [][][]int{{{1}}} it will be 2.
2431 Parse::composite_lit(Type* type, int depth, source_location location)
2433 gcc_assert(this->peek_token()->is_op(OPERATOR_LCURLY));
2434 this->advance_token();
2436 if (this->peek_token()->is_op(OPERATOR_RCURLY))
2438 this->advance_token();
2439 return Expression::make_composite_literal(type, depth, false, NULL,
2443 bool has_keys = false;
2444 Expression_list* vals = new Expression_list;
2448 bool is_type_omitted = false;
2450 const Token* token = this->peek_token();
2452 if (!token->is_op(OPERATOR_LCURLY))
2453 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2456 // This must be a composite literal inside another composite
2457 // literal, with the type omitted for the inner one.
2458 val = this->composite_lit(type, depth + 1, token->location());
2459 is_type_omitted = true;
2462 token = this->peek_token();
2463 if (!token->is_op(OPERATOR_COLON))
2466 vals->push_back(NULL);
2470 if (is_type_omitted && !val->is_error_expression())
2472 error_at(this->location(), "unexpected %<:%>");
2473 val = Expression::make_error(this->location());
2476 this->advance_token();
2478 if (!has_keys && !vals->empty())
2480 Expression_list* newvals = new Expression_list;
2481 for (Expression_list::const_iterator p = vals->begin();
2485 newvals->push_back(NULL);
2486 newvals->push_back(*p);
2493 if (val->unknown_expression() != NULL)
2494 val->unknown_expression()->set_is_composite_literal_key();
2496 vals->push_back(val);
2498 if (!token->is_op(OPERATOR_LCURLY))
2499 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2502 // This must be a composite literal inside another
2503 // composite literal, with the type omitted for the
2505 val = this->composite_lit(type, depth + 1, token->location());
2508 token = this->peek_token();
2511 vals->push_back(val);
2513 if (token->is_op(OPERATOR_COMMA))
2515 if (this->advance_token()->is_op(OPERATOR_RCURLY))
2517 this->advance_token();
2521 else if (token->is_op(OPERATOR_RCURLY))
2523 this->advance_token();
2528 error_at(this->location(), "expected %<,%> or %<}%>");
2531 while (!token->is_eof()
2532 && (depth > 0 || !token->is_op(OPERATOR_RCURLY)))
2534 if (token->is_op(OPERATOR_LCURLY))
2536 else if (token->is_op(OPERATOR_RCURLY))
2538 token = this->advance_token();
2540 if (token->is_op(OPERATOR_RCURLY))
2541 this->advance_token();
2543 return Expression::make_error(location);
2547 return Expression::make_composite_literal(type, depth, has_keys, vals,
2551 // FunctionLit = "func" Signature Block .
2554 Parse::function_lit()
2556 source_location location = this->location();
2557 gcc_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
2558 this->advance_token();
2560 Enclosing_vars hold_enclosing_vars;
2561 hold_enclosing_vars.swap(this->enclosing_vars_);
2563 Function_type* type = this->signature(NULL, location);
2565 type = Type::make_function_type(NULL, NULL, NULL, location);
2567 // For a function literal, the next token must be a '{'. If we
2568 // don't see that, then we may have a type expression.
2569 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
2570 return Expression::make_type(type, location);
2572 Named_object* no = this->gogo_->start_function("", type, true, location);
2574 source_location end_loc = this->block();
2576 this->gogo_->finish_function(end_loc);
2578 hold_enclosing_vars.swap(this->enclosing_vars_);
2580 Expression* closure = this->create_closure(no, &hold_enclosing_vars,
2583 return Expression::make_func_reference(no, closure, location);
2586 // Create a closure for the nested function FUNCTION. This is based
2587 // on ENCLOSING_VARS, which is a list of all variables defined in
2588 // enclosing functions and referenced from FUNCTION. A closure is the
2589 // address of a struct which contains the addresses of all the
2590 // referenced variables. This returns NULL if no closure is required.
2593 Parse::create_closure(Named_object* function, Enclosing_vars* enclosing_vars,
2594 source_location location)
2596 if (enclosing_vars->empty())
2599 // Get the variables in order by their field index.
2601 size_t enclosing_var_count = enclosing_vars->size();
2602 std::vector<Enclosing_var> ev(enclosing_var_count);
2603 for (Enclosing_vars::const_iterator p = enclosing_vars->begin();
2604 p != enclosing_vars->end();
2606 ev[p->index()] = *p;
2608 // Build an initializer for a composite literal of the closure's
2611 Named_object* enclosing_function = this->gogo_->current_function();
2612 Expression_list* initializer = new Expression_list;
2613 for (size_t i = 0; i < enclosing_var_count; ++i)
2615 gcc_assert(ev[i].index() == i);
2616 Named_object* var = ev[i].var();
2618 if (ev[i].in_function() == enclosing_function)
2619 ref = Expression::make_var_reference(var, location);
2621 ref = this->enclosing_var_reference(ev[i].in_function(), var,
2623 Expression* refaddr = Expression::make_unary(OPERATOR_AND, ref,
2625 initializer->push_back(refaddr);
2628 Named_object* closure_var = function->func_value()->closure_var();
2629 Struct_type* st = closure_var->var_value()->type()->deref()->struct_type();
2630 Expression* cv = Expression::make_struct_composite_literal(st, initializer,
2632 return Expression::make_heap_composite(cv, location);
2635 // PrimaryExpr = Operand { Selector | Index | Slice | TypeGuard | Call } .
2637 // If MAY_BE_SINK is true, this expression may be "_".
2639 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
2642 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2643 // guard (var := expr.("type") using the literal keyword "type").
2646 Parse::primary_expr(bool may_be_sink, bool may_be_composite_lit,
2647 bool* is_type_switch)
2649 source_location start_loc = this->location();
2650 bool is_parenthesized = this->peek_token()->is_op(OPERATOR_LPAREN);
2652 Expression* ret = this->operand(may_be_sink);
2654 // An unknown name followed by a curly brace must be a composite
2655 // literal, and the unknown name must be a type.
2656 if (may_be_composite_lit
2657 && !is_parenthesized
2658 && ret->unknown_expression() != NULL
2659 && this->peek_token()->is_op(OPERATOR_LCURLY))
2661 Named_object* no = ret->unknown_expression()->named_object();
2662 Type* type = Type::make_forward_declaration(no);
2663 ret = Expression::make_type(type, ret->location());
2666 // We handle composite literals and type casts here, as it is the
2667 // easiest way to handle types which are in parentheses, as in
2669 if (ret->is_type_expression())
2671 if (this->peek_token()->is_op(OPERATOR_LCURLY))
2673 if (is_parenthesized)
2675 "cannot parenthesize type in composite literal");
2676 ret = this->composite_lit(ret->type(), 0, ret->location());
2678 else if (this->peek_token()->is_op(OPERATOR_LPAREN))
2680 source_location loc = this->location();
2681 this->advance_token();
2682 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true,
2684 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2685 error_at(this->location(), "expected %<)%>");
2687 this->advance_token();
2688 if (expr->is_error_expression())
2690 ret = Expression::make_cast(ret->type(), expr, loc);
2696 const Token* token = this->peek_token();
2697 if (token->is_op(OPERATOR_LPAREN))
2698 ret = this->call(this->verify_not_sink(ret));
2699 else if (token->is_op(OPERATOR_DOT))
2701 ret = this->selector(this->verify_not_sink(ret), is_type_switch);
2702 if (is_type_switch != NULL && *is_type_switch)
2705 else if (token->is_op(OPERATOR_LSQUARE))
2706 ret = this->index(this->verify_not_sink(ret));
2714 // Selector = "." identifier .
2715 // TypeGuard = "." "(" QualifiedIdent ")" .
2717 // Note that Operand can expand to QualifiedIdent, which contains a
2718 // ".". That is handled directly in operand when it sees a package
2721 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2722 // guard (var := expr.("type") using the literal keyword "type").
2725 Parse::selector(Expression* left, bool* is_type_switch)
2727 gcc_assert(this->peek_token()->is_op(OPERATOR_DOT));
2728 source_location location = this->location();
2730 const Token* token = this->advance_token();
2731 if (token->is_identifier())
2733 // This could be a field in a struct, or a method in an
2734 // interface, or a method associated with a type. We can't know
2735 // which until we have seen all the types.
2737 this->gogo_->pack_hidden_name(token->identifier(),
2738 token->is_identifier_exported());
2739 if (token->identifier() == "_")
2741 error_at(this->location(), "invalid use of %<_%>");
2742 name = this->gogo_->pack_hidden_name("blank", false);
2744 this->advance_token();
2745 return Expression::make_selector(left, name, location);
2747 else if (token->is_op(OPERATOR_LPAREN))
2749 this->advance_token();
2751 if (!this->peek_token()->is_keyword(KEYWORD_TYPE))
2752 type = this->type();
2755 if (is_type_switch != NULL)
2756 *is_type_switch = true;
2759 error_at(this->location(),
2760 "use of %<.(type)%> outside type switch");
2761 type = Type::make_error_type();
2763 this->advance_token();
2765 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2766 error_at(this->location(), "missing %<)%>");
2768 this->advance_token();
2769 if (is_type_switch != NULL && *is_type_switch)
2771 return Expression::make_type_guard(left, type, location);
2775 error_at(this->location(), "expected identifier or %<(%>");
2780 // Index = "[" Expression "]" .
2781 // Slice = "[" Expression ":" [ Expression ] "]" .
2784 Parse::index(Expression* expr)
2786 source_location location = this->location();
2787 gcc_assert(this->peek_token()->is_op(OPERATOR_LSQUARE));
2788 this->advance_token();
2791 if (!this->peek_token()->is_op(OPERATOR_COLON))
2792 start = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2796 mpz_init_set_ui(zero, 0);
2797 start = Expression::make_integer(&zero, NULL, location);
2801 Expression* end = NULL;
2802 if (this->peek_token()->is_op(OPERATOR_COLON))
2804 // We use nil to indicate a missing high expression.
2805 if (this->advance_token()->is_op(OPERATOR_RSQUARE))
2806 end = Expression::make_nil(this->location());
2808 end = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2810 if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
2811 error_at(this->location(), "missing %<]%>");
2813 this->advance_token();
2814 return Expression::make_index(expr, start, end, location);
2817 // Call = "(" [ ArgumentList [ "," ] ] ")" .
2818 // ArgumentList = ExpressionList [ "..." ] .
2821 Parse::call(Expression* func)
2823 gcc_assert(this->peek_token()->is_op(OPERATOR_LPAREN));
2824 Expression_list* args = NULL;
2825 bool is_varargs = false;
2826 const Token* token = this->advance_token();
2827 if (!token->is_op(OPERATOR_RPAREN))
2829 args = this->expression_list(NULL, false);
2830 token = this->peek_token();
2831 if (token->is_op(OPERATOR_ELLIPSIS))
2834 token = this->advance_token();
2837 if (token->is_op(OPERATOR_COMMA))
2838 token = this->advance_token();
2839 if (!token->is_op(OPERATOR_RPAREN))
2840 error_at(this->location(), "missing %<)%>");
2842 this->advance_token();
2843 if (func->is_error_expression())
2845 return Expression::make_call(func, args, is_varargs, func->location());
2848 // Return an expression for a single unqualified identifier.
2851 Parse::id_to_expression(const std::string& name, source_location location)
2853 Named_object* in_function;
2854 Named_object* named_object = this->gogo_->lookup(name, &in_function);
2855 if (named_object == NULL)
2856 named_object = this->gogo_->add_unknown_name(name, location);
2858 if (in_function != NULL
2859 && in_function != this->gogo_->current_function()
2860 && (named_object->is_variable() || named_object->is_result_variable()))
2861 return this->enclosing_var_reference(in_function, named_object,
2864 switch (named_object->classification())
2866 case Named_object::NAMED_OBJECT_CONST:
2867 return Expression::make_const_reference(named_object, location);
2868 case Named_object::NAMED_OBJECT_VAR:
2869 case Named_object::NAMED_OBJECT_RESULT_VAR:
2870 return Expression::make_var_reference(named_object, location);
2871 case Named_object::NAMED_OBJECT_SINK:
2872 return Expression::make_sink(location);
2873 case Named_object::NAMED_OBJECT_FUNC:
2874 case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
2875 return Expression::make_func_reference(named_object, NULL, location);
2876 case Named_object::NAMED_OBJECT_UNKNOWN:
2877 return Expression::make_unknown_reference(named_object, location);
2879 error_at(this->location(), "unexpected type of identifier");
2880 return Expression::make_error(location);
2884 // Expression = UnaryExpr { binary_op Expression } .
2886 // PRECEDENCE is the precedence of the current operator.
2888 // If MAY_BE_SINK is true, this expression may be "_".
2890 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
2893 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2894 // guard (var := expr.("type") using the literal keyword "type").
2897 Parse::expression(Precedence precedence, bool may_be_sink,
2898 bool may_be_composite_lit, bool* is_type_switch)
2900 Expression* left = this->unary_expr(may_be_sink, may_be_composite_lit,
2905 if (is_type_switch != NULL && *is_type_switch)
2908 const Token* token = this->peek_token();
2909 if (token->classification() != Token::TOKEN_OPERATOR)
2915 Precedence right_precedence;
2916 switch (token->op())
2919 right_precedence = PRECEDENCE_OROR;
2921 case OPERATOR_ANDAND:
2922 right_precedence = PRECEDENCE_ANDAND;
2924 case OPERATOR_CHANOP:
2925 right_precedence = PRECEDENCE_CHANOP;
2928 case OPERATOR_NOTEQ:
2933 right_precedence = PRECEDENCE_RELOP;
2936 case OPERATOR_MINUS:
2939 right_precedence = PRECEDENCE_ADDOP;
2944 case OPERATOR_LSHIFT:
2945 case OPERATOR_RSHIFT:
2947 case OPERATOR_BITCLEAR:
2948 right_precedence = PRECEDENCE_MULOP;
2951 right_precedence = PRECEDENCE_INVALID;
2955 if (right_precedence == PRECEDENCE_INVALID)
2961 Operator op = token->op();
2962 source_location binop_location = token->location();
2964 if (precedence >= right_precedence)
2966 // We've already seen A * B, and we see + C. We want to
2967 // return so that A * B becomes a group.
2971 this->advance_token();
2973 left = this->verify_not_sink(left);
2974 Expression* right = this->expression(right_precedence, false,
2975 may_be_composite_lit,
2977 if (op == OPERATOR_CHANOP)
2978 left = Expression::make_send(left, right, binop_location);
2980 left = Expression::make_binary(op, left, right, binop_location);
2985 Parse::expression_may_start_here()
2987 const Token* token = this->peek_token();
2988 switch (token->classification())
2990 case Token::TOKEN_INVALID:
2991 case Token::TOKEN_EOF:
2993 case Token::TOKEN_KEYWORD:
2994 switch (token->keyword())
2999 case KEYWORD_STRUCT:
3000 case KEYWORD_INTERFACE:
3005 case Token::TOKEN_IDENTIFIER:
3007 case Token::TOKEN_STRING:
3009 case Token::TOKEN_OPERATOR:
3010 switch (token->op())
3013 case OPERATOR_MINUS:
3017 case OPERATOR_CHANOP:
3019 case OPERATOR_LPAREN:
3020 case OPERATOR_LSQUARE:
3025 case Token::TOKEN_INTEGER:
3026 case Token::TOKEN_FLOAT:
3027 case Token::TOKEN_IMAGINARY:
3034 // UnaryExpr = unary_op UnaryExpr | PrimaryExpr .
3036 // If MAY_BE_SINK is true, this expression may be "_".
3038 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3041 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3042 // guard (var := expr.("type") using the literal keyword "type").
3045 Parse::unary_expr(bool may_be_sink, bool may_be_composite_lit,
3046 bool* is_type_switch)
3048 const Token* token = this->peek_token();
3049 if (token->is_op(OPERATOR_PLUS)
3050 || token->is_op(OPERATOR_MINUS)
3051 || token->is_op(OPERATOR_NOT)
3052 || token->is_op(OPERATOR_XOR)
3053 || token->is_op(OPERATOR_CHANOP)
3054 || token->is_op(OPERATOR_MULT)
3055 || token->is_op(OPERATOR_AND))
3057 source_location location = token->location();
3058 Operator op = token->op();
3059 this->advance_token();
3061 if (op == OPERATOR_CHANOP
3062 && this->peek_token()->is_keyword(KEYWORD_CHAN))
3064 // This is "<- chan" which must be the start of a type.
3065 this->unget_token(Token::make_operator_token(op, location));
3066 return Expression::make_type(this->type(), location);
3069 Expression* expr = this->unary_expr(false, may_be_composite_lit, NULL);
3070 if (expr->is_error_expression())
3072 else if (op == OPERATOR_MULT && expr->is_type_expression())
3073 expr = Expression::make_type(Type::make_pointer_type(expr->type()),
3075 else if (op == OPERATOR_AND && expr->is_composite_literal())
3076 expr = Expression::make_heap_composite(expr, location);
3077 else if (op != OPERATOR_CHANOP)
3078 expr = Expression::make_unary(op, expr, location);
3080 expr = Expression::make_receive(expr, location);
3084 return this->primary_expr(may_be_sink, may_be_composite_lit,
3089 // Declaration | LabeledStmt | SimpleStmt |
3090 // GoStmt | ReturnStmt | BreakStmt | ContinueStmt | GotoStmt |
3091 // FallthroughStmt | Block | IfStmt | SwitchStmt | SelectStmt | ForStmt |
3094 // LABEL is the label of this statement if it has one.
3097 Parse::statement(const Label* label)
3099 const Token* token = this->peek_token();
3100 switch (token->classification())
3102 case Token::TOKEN_KEYWORD:
3104 switch (token->keyword())
3109 this->declaration();
3113 case KEYWORD_STRUCT:
3114 case KEYWORD_INTERFACE:
3115 this->simple_stat(true, false, NULL, NULL);
3119 this->go_or_defer_stat();
3121 case KEYWORD_RETURN:
3122 this->return_stat();
3127 case KEYWORD_CONTINUE:
3128 this->continue_stat();
3136 case KEYWORD_SWITCH:
3137 this->switch_stat(label);
3139 case KEYWORD_SELECT:
3140 this->select_stat(label);
3143 this->for_stat(label);
3146 error_at(this->location(), "expected statement");
3147 this->advance_token();
3153 case Token::TOKEN_IDENTIFIER:
3155 std::string identifier = token->identifier();
3156 bool is_exported = token->is_identifier_exported();
3157 source_location location = token->location();
3158 if (this->advance_token()->is_op(OPERATOR_COLON))
3160 this->advance_token();
3161 this->labeled_stmt(identifier, location);
3165 this->unget_token(Token::make_identifier_token(identifier,
3168 this->simple_stat(true, false, NULL, NULL);
3173 case Token::TOKEN_OPERATOR:
3174 if (token->is_op(OPERATOR_LCURLY))
3176 source_location location = token->location();
3177 this->gogo_->start_block(location);
3178 source_location end_loc = this->block();
3179 this->gogo_->add_block(this->gogo_->finish_block(end_loc),
3182 else if (!token->is_op(OPERATOR_SEMICOLON))
3183 this->simple_stat(true, false, NULL, NULL);
3186 case Token::TOKEN_STRING:
3187 case Token::TOKEN_INTEGER:
3188 case Token::TOKEN_FLOAT:
3189 case Token::TOKEN_IMAGINARY:
3190 this->simple_stat(true, false, NULL, NULL);
3194 error_at(this->location(), "expected statement");
3195 this->advance_token();
3201 Parse::statement_may_start_here()
3203 const Token* token = this->peek_token();
3204 switch (token->classification())
3206 case Token::TOKEN_KEYWORD:
3208 switch (token->keyword())
3215 case KEYWORD_STRUCT:
3216 case KEYWORD_INTERFACE:
3219 case KEYWORD_RETURN:
3221 case KEYWORD_CONTINUE:
3224 case KEYWORD_SWITCH:
3225 case KEYWORD_SELECT:
3235 case Token::TOKEN_IDENTIFIER:
3238 case Token::TOKEN_OPERATOR:
3239 if (token->is_op(OPERATOR_LCURLY)
3240 || token->is_op(OPERATOR_SEMICOLON))
3243 return this->expression_may_start_here();
3245 case Token::TOKEN_STRING:
3246 case Token::TOKEN_INTEGER:
3247 case Token::TOKEN_FLOAT:
3248 case Token::TOKEN_IMAGINARY:
3256 // LabeledStmt = Label ":" Statement .
3257 // Label = identifier .
3260 Parse::labeled_stmt(const std::string& label_name, source_location location)
3262 Label* label = this->gogo_->add_label_definition(label_name, location);
3264 if (this->peek_token()->is_op(OPERATOR_RCURLY))
3266 // This is a label at the end of a block. A program is
3267 // permitted to omit a semicolon here.
3271 if (!this->statement_may_start_here())
3273 error_at(location, "missing statement after label");
3274 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
3279 this->statement(label);
3283 // ExpressionStat | IncDecStat | Assignment | SimpleVarDecl .
3285 // In order to make this work for if and switch statements, if
3286 // RETURN_EXP is true, and we see an ExpressionStat, we return the
3287 // expression rather than adding an expression statement to the
3288 // current block. If we see something other than an ExpressionStat,
3289 // we add the statement and return NULL.
3291 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
3294 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
3295 // guard (var := expr.("type") using the literal keyword "type").
3298 Parse::simple_stat(bool may_be_composite_lit, bool return_exp,
3299 Range_clause* p_range_clause, Type_switch* p_type_switch)
3301 const Token* token = this->peek_token();
3303 // An identifier follow by := is a SimpleVarDecl.
3304 if (token->is_identifier())
3306 std::string identifier = token->identifier();
3307 bool is_exported = token->is_identifier_exported();
3308 source_location location = token->location();
3310 token = this->advance_token();
3311 if (token->is_op(OPERATOR_COLONEQ)
3312 || token->is_op(OPERATOR_COMMA))
3314 identifier = this->gogo_->pack_hidden_name(identifier, is_exported);
3315 this->simple_var_decl_or_assignment(identifier, location,
3317 (token->is_op(OPERATOR_COLONEQ)
3323 this->unget_token(Token::make_identifier_token(identifier, is_exported,
3327 Expression* exp = this->expression(PRECEDENCE_NORMAL, true,
3328 may_be_composite_lit,
3329 (p_type_switch == NULL
3331 : &p_type_switch->found));
3332 if (p_type_switch != NULL && p_type_switch->found)
3334 p_type_switch->name.clear();
3335 p_type_switch->location = exp->location();
3336 p_type_switch->expr = this->verify_not_sink(exp);
3339 token = this->peek_token();
3340 if (token->is_op(OPERATOR_PLUSPLUS) || token->is_op(OPERATOR_MINUSMINUS))
3341 this->inc_dec_stat(this->verify_not_sink(exp));
3342 else if (token->is_op(OPERATOR_COMMA)
3343 || token->is_op(OPERATOR_EQ))
3344 this->assignment(exp, p_range_clause);
3345 else if (token->is_op(OPERATOR_PLUSEQ)
3346 || token->is_op(OPERATOR_MINUSEQ)
3347 || token->is_op(OPERATOR_OREQ)
3348 || token->is_op(OPERATOR_XOREQ)
3349 || token->is_op(OPERATOR_MULTEQ)
3350 || token->is_op(OPERATOR_DIVEQ)
3351 || token->is_op(OPERATOR_MODEQ)
3352 || token->is_op(OPERATOR_LSHIFTEQ)
3353 || token->is_op(OPERATOR_RSHIFTEQ)
3354 || token->is_op(OPERATOR_ANDEQ)
3355 || token->is_op(OPERATOR_BITCLEAREQ))
3356 this->assignment(this->verify_not_sink(exp), p_range_clause);
3357 else if (return_exp)
3358 return this->verify_not_sink(exp);
3360 this->expression_stat(this->verify_not_sink(exp));
3366 Parse::simple_stat_may_start_here()
3368 return this->expression_may_start_here();
3371 // Parse { Statement ";" } which is used in a few places. The list of
3372 // statements may end with a right curly brace, in which case the
3373 // semicolon may be omitted.
3376 Parse::statement_list()
3378 while (this->statement_may_start_here())
3380 this->statement(NULL);
3381 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3382 this->advance_token();
3383 else if (this->peek_token()->is_op(OPERATOR_RCURLY))
3387 if (!this->peek_token()->is_eof() || !saw_errors())
3388 error_at(this->location(), "expected %<;%> or %<}%> or newline");
3389 if (!this->skip_past_error(OPERATOR_RCURLY))
3396 Parse::statement_list_may_start_here()
3398 return this->statement_may_start_here();
3401 // ExpressionStat = Expression .
3404 Parse::expression_stat(Expression* exp)
3406 exp->discarding_value();
3407 this->gogo_->add_statement(Statement::make_statement(exp));
3410 // IncDecStat = Expression ( "++" | "--" ) .
3413 Parse::inc_dec_stat(Expression* exp)
3415 const Token* token = this->peek_token();
3417 // Lvalue maps require special handling.
3418 if (exp->index_expression() != NULL)
3419 exp->index_expression()->set_is_lvalue();
3421 if (token->is_op(OPERATOR_PLUSPLUS))
3422 this->gogo_->add_statement(Statement::make_inc_statement(exp));
3423 else if (token->is_op(OPERATOR_MINUSMINUS))
3424 this->gogo_->add_statement(Statement::make_dec_statement(exp));
3427 this->advance_token();
3430 // Assignment = ExpressionList assign_op ExpressionList .
3432 // EXP is an expression that we have already parsed.
3434 // If RANGE_CLAUSE is not NULL, then this will recognize a
3438 Parse::assignment(Expression* expr, Range_clause* p_range_clause)
3440 Expression_list* vars;
3441 if (!this->peek_token()->is_op(OPERATOR_COMMA))
3443 vars = new Expression_list();
3444 vars->push_back(expr);
3448 this->advance_token();
3449 vars = this->expression_list(expr, true);
3452 this->tuple_assignment(vars, p_range_clause);
3455 // An assignment statement. LHS is the list of expressions which
3456 // appear on the left hand side.
3458 // If RANGE_CLAUSE is not NULL, then this will recognize a
3462 Parse::tuple_assignment(Expression_list* lhs, Range_clause* p_range_clause)
3464 const Token* token = this->peek_token();
3465 if (!token->is_op(OPERATOR_EQ)
3466 && !token->is_op(OPERATOR_PLUSEQ)
3467 && !token->is_op(OPERATOR_MINUSEQ)
3468 && !token->is_op(OPERATOR_OREQ)
3469 && !token->is_op(OPERATOR_XOREQ)
3470 && !token->is_op(OPERATOR_MULTEQ)
3471 && !token->is_op(OPERATOR_DIVEQ)
3472 && !token->is_op(OPERATOR_MODEQ)
3473 && !token->is_op(OPERATOR_LSHIFTEQ)
3474 && !token->is_op(OPERATOR_RSHIFTEQ)
3475 && !token->is_op(OPERATOR_ANDEQ)
3476 && !token->is_op(OPERATOR_BITCLEAREQ))
3478 error_at(this->location(), "expected assignment operator");
3481 Operator op = token->op();
3482 source_location location = token->location();
3484 token = this->advance_token();
3486 if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
3488 if (op != OPERATOR_EQ)
3489 error_at(this->location(), "range clause requires %<=%>");
3490 this->range_clause_expr(lhs, p_range_clause);
3494 Expression_list* vals = this->expression_list(NULL, false);
3496 // We've parsed everything; check for errors.
3497 if (lhs == NULL || vals == NULL)
3499 for (Expression_list::const_iterator pe = lhs->begin();
3503 if ((*pe)->is_error_expression())
3505 if (op != OPERATOR_EQ && (*pe)->is_sink_expression())
3506 error_at((*pe)->location(), "cannot use _ as value");
3508 for (Expression_list::const_iterator pe = vals->begin();
3512 if ((*pe)->is_error_expression())
3516 // Map expressions act differently when they are lvalues.
3517 for (Expression_list::iterator plv = lhs->begin();
3520 if ((*plv)->index_expression() != NULL)
3521 (*plv)->index_expression()->set_is_lvalue();
3523 Call_expression* call;
3524 Index_expression* map_index;
3525 Receive_expression* receive;
3526 Type_guard_expression* type_guard;
3527 if (lhs->size() == vals->size())
3530 if (lhs->size() > 1)
3532 if (op != OPERATOR_EQ)
3533 error_at(location, "multiple values only permitted with %<=%>");
3534 s = Statement::make_tuple_assignment(lhs, vals, location);
3538 if (op == OPERATOR_EQ)
3539 s = Statement::make_assignment(lhs->front(), vals->front(),
3542 s = Statement::make_assignment_operation(op, lhs->front(),
3543 vals->front(), location);
3547 this->gogo_->add_statement(s);
3549 else if (vals->size() == 1
3550 && (call = (*vals->begin())->call_expression()) != NULL)
3552 if (op != OPERATOR_EQ)
3553 error_at(location, "multiple results only permitted with %<=%>");
3555 vals = new Expression_list;
3556 for (unsigned int i = 0; i < lhs->size(); ++i)
3557 vals->push_back(Expression::make_call_result(call, i));
3558 Statement* s = Statement::make_tuple_assignment(lhs, vals, location);
3559 this->gogo_->add_statement(s);
3561 else if (lhs->size() == 2
3562 && vals->size() == 1
3563 && (map_index = (*vals->begin())->index_expression()) != NULL)
3565 if (op != OPERATOR_EQ)
3566 error_at(location, "two values from map requires %<=%>");
3567 Expression* val = lhs->front();
3568 Expression* present = lhs->back();
3569 Statement* s = Statement::make_tuple_map_assignment(val, present,
3570 map_index, location);
3571 this->gogo_->add_statement(s);
3573 else if (lhs->size() == 1
3574 && vals->size() == 2
3575 && (map_index = lhs->front()->index_expression()) != NULL)
3577 if (op != OPERATOR_EQ)
3578 error_at(location, "assigning tuple to map index requires %<=%>");
3579 Expression* val = vals->front();
3580 Expression* should_set = vals->back();
3581 Statement* s = Statement::make_map_assignment(map_index, val, should_set,
3583 this->gogo_->add_statement(s);
3585 else if (lhs->size() == 2
3586 && vals->size() == 1
3587 && (receive = (*vals->begin())->receive_expression()) != NULL)
3589 if (op != OPERATOR_EQ)
3590 error_at(location, "two values from receive requires %<=%>");
3591 Expression* val = lhs->front();
3592 Expression* success = lhs->back();
3593 Expression* channel = receive->channel();
3594 Statement* s = Statement::make_tuple_receive_assignment(val, success,
3597 this->gogo_->add_statement(s);
3599 else if (lhs->size() == 2
3600 && vals->size() == 1
3601 && (type_guard = (*vals->begin())->type_guard_expression()) != NULL)
3603 if (op != OPERATOR_EQ)
3604 error_at(location, "two values from type guard requires %<=%>");
3605 Expression* val = lhs->front();
3606 Expression* ok = lhs->back();
3607 Expression* expr = type_guard->expr();
3608 Type* type = type_guard->type();
3609 Statement* s = Statement::make_tuple_type_guard_assignment(val, ok,
3612 this->gogo_->add_statement(s);
3616 error_at(location, "number of variables does not match number of values");
3620 // GoStat = "go" Expression .
3621 // DeferStat = "defer" Expression .
3624 Parse::go_or_defer_stat()
3626 gcc_assert(this->peek_token()->is_keyword(KEYWORD_GO)
3627 || this->peek_token()->is_keyword(KEYWORD_DEFER));
3628 bool is_go = this->peek_token()->is_keyword(KEYWORD_GO);
3629 source_location stat_location = this->location();
3630 this->advance_token();
3631 source_location expr_location = this->location();
3632 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
3633 Call_expression* call_expr = expr->call_expression();
3634 if (call_expr == NULL)
3636 error_at(expr_location, "expected call expression");
3640 // Make it easier to simplify go/defer statements by putting every
3641 // statement in its own block.
3642 this->gogo_->start_block(stat_location);
3645 stat = Statement::make_go_statement(call_expr, stat_location);
3647 stat = Statement::make_defer_statement(call_expr, stat_location);
3648 this->gogo_->add_statement(stat);
3649 this->gogo_->add_block(this->gogo_->finish_block(stat_location),
3653 // ReturnStat = "return" [ ExpressionList ] .
3656 Parse::return_stat()
3658 gcc_assert(this->peek_token()->is_keyword(KEYWORD_RETURN));
3659 source_location location = this->location();
3660 this->advance_token();
3661 Expression_list* vals = NULL;
3662 if (this->expression_may_start_here())
3663 vals = this->expression_list(NULL, false);
3664 const Function* function = this->gogo_->current_function()->func_value();
3665 const Typed_identifier_list* results = function->type()->results();
3666 this->gogo_->add_statement(Statement::make_return_statement(results, vals,
3670 // IfStat = "if" [ [ SimpleStat ] ";" ] [ Condition ]
3671 // Block [ "else" Statement ] .
3676 gcc_assert(this->peek_token()->is_keyword(KEYWORD_IF));
3677 source_location location = this->location();
3678 this->advance_token();
3680 this->gogo_->start_block(location);
3682 Expression* cond = NULL;
3683 if (this->simple_stat_may_start_here())
3684 cond = this->simple_stat(false, true, NULL, NULL);
3685 if (cond != NULL && this->peek_token()->is_op(OPERATOR_SEMICOLON))
3687 // The SimpleStat is an expression statement.
3688 this->expression_stat(cond);
3693 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3694 this->advance_token();
3695 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3696 cond = this->expression(PRECEDENCE_NORMAL, false, false, NULL);
3699 this->gogo_->start_block(this->location());
3700 source_location end_loc = this->block();
3701 Block* then_block = this->gogo_->finish_block(end_loc);
3703 // Check for the easy error of a newline before "else".
3704 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3706 source_location semi_loc = this->location();
3707 if (this->advance_token()->is_keyword(KEYWORD_ELSE))
3708 error_at(this->location(),
3709 "unexpected semicolon or newline before %<else%>");
3711 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
3715 Block* else_block = NULL;
3716 if (this->peek_token()->is_keyword(KEYWORD_ELSE))
3718 this->advance_token();
3719 // We create a block to gather the statement.
3720 this->gogo_->start_block(this->location());
3721 this->statement(NULL);
3722 else_block = this->gogo_->finish_block(this->location());
3725 this->gogo_->add_statement(Statement::make_if_statement(cond, then_block,
3729 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3733 // SwitchStmt = ExprSwitchStmt | TypeSwitchStmt .
3734 // ExprSwitchStmt = "switch" [ [ SimpleStat ] ";" ] [ Expression ]
3735 // "{" { ExprCaseClause } "}" .
3736 // TypeSwitchStmt = "switch" [ [ SimpleStat ] ";" ] TypeSwitchGuard
3737 // "{" { TypeCaseClause } "}" .
3738 // TypeSwitchGuard = [ identifier ":=" ] Expression "." "(" "type" ")" .
3741 Parse::switch_stat(const Label* label)
3743 gcc_assert(this->peek_token()->is_keyword(KEYWORD_SWITCH));
3744 source_location location = this->location();
3745 this->advance_token();
3747 this->gogo_->start_block(location);
3749 Expression* switch_val = NULL;
3750 Type_switch type_switch;
3751 if (this->simple_stat_may_start_here())
3752 switch_val = this->simple_stat(false, true, NULL, &type_switch);
3753 if (switch_val != NULL && this->peek_token()->is_op(OPERATOR_SEMICOLON))
3755 // The SimpleStat is an expression statement.
3756 this->expression_stat(switch_val);
3759 if (switch_val == NULL && !type_switch.found)
3761 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3762 this->advance_token();
3763 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3765 if (this->peek_token()->is_identifier())
3767 const Token* token = this->peek_token();
3768 std::string identifier = token->identifier();
3769 bool is_exported = token->is_identifier_exported();
3770 source_location id_loc = token->location();
3772 token = this->advance_token();
3773 bool is_coloneq = token->is_op(OPERATOR_COLONEQ);
3774 this->unget_token(Token::make_identifier_token(identifier,
3779 // This must be a TypeSwitchGuard.
3780 switch_val = this->simple_stat(false, true, NULL,
3782 if (!type_switch.found
3783 && !switch_val->is_error_expression())
3785 error_at(id_loc, "expected type switch assignment");
3786 switch_val = Expression::make_error(id_loc);
3790 if (switch_val == NULL && !type_switch.found)
3792 switch_val = this->expression(PRECEDENCE_NORMAL, false, false,
3793 &type_switch.found);
3794 if (type_switch.found)
3796 type_switch.name.clear();
3797 type_switch.expr = switch_val;
3798 type_switch.location = switch_val->location();
3804 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3806 source_location token_loc = this->location();
3807 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
3808 && this->advance_token()->is_op(OPERATOR_LCURLY))
3809 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
3812 error_at(this->location(), "expected %<{%>");
3813 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3818 this->advance_token();
3820 Statement* statement;
3821 if (type_switch.found)
3822 statement = this->type_switch_body(label, type_switch, location);
3824 statement = this->expr_switch_body(label, switch_val, location);
3826 if (statement != NULL)
3827 this->gogo_->add_statement(statement);
3829 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3833 // The body of an expression switch.
3834 // "{" { ExprCaseClause } "}"
3837 Parse::expr_switch_body(const Label* label, Expression* switch_val,
3838 source_location location)
3840 Switch_statement* statement = Statement::make_switch_statement(switch_val,
3843 this->push_break_statement(statement, label);
3845 Case_clauses* case_clauses = new Case_clauses();
3846 bool saw_default = false;
3847 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
3849 if (this->peek_token()->is_eof())
3852 error_at(this->location(), "missing %<}%>");
3855 this->expr_case_clause(case_clauses, &saw_default);
3857 this->advance_token();
3859 statement->add_clauses(case_clauses);
3861 this->pop_break_statement();
3866 // ExprCaseClause = ExprSwitchCase ":" [ StatementList ] .
3867 // FallthroughStat = "fallthrough" .
3870 Parse::expr_case_clause(Case_clauses* clauses, bool* saw_default)
3872 source_location location = this->location();
3874 bool is_default = false;
3875 Expression_list* vals = this->expr_switch_case(&is_default);
3877 if (!this->peek_token()->is_op(OPERATOR_COLON))
3880 error_at(this->location(), "expected %<:%>");
3884 this->advance_token();
3886 Block* statements = NULL;
3887 if (this->statement_list_may_start_here())
3889 this->gogo_->start_block(this->location());
3890 this->statement_list();
3891 statements = this->gogo_->finish_block(this->location());
3894 bool is_fallthrough = false;
3895 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH))
3897 is_fallthrough = true;
3898 if (this->advance_token()->is_op(OPERATOR_SEMICOLON))
3899 this->advance_token();
3906 error_at(location, "multiple defaults in switch");
3909 *saw_default = true;
3912 if (is_default || vals != NULL)
3913 clauses->add(vals, is_default, statements, is_fallthrough, location);
3916 // ExprSwitchCase = "case" ExpressionList | "default" .
3919 Parse::expr_switch_case(bool* is_default)
3921 const Token* token = this->peek_token();
3922 if (token->is_keyword(KEYWORD_CASE))
3924 this->advance_token();
3925 return this->expression_list(NULL, false);
3927 else if (token->is_keyword(KEYWORD_DEFAULT))
3929 this->advance_token();
3936 error_at(this->location(), "expected %<case%> or %<default%>");
3937 if (!token->is_op(OPERATOR_RCURLY))
3938 this->advance_token();
3943 // The body of a type switch.
3944 // "{" { TypeCaseClause } "}" .
3947 Parse::type_switch_body(const Label* label, const Type_switch& type_switch,
3948 source_location location)
3950 Named_object* switch_no = NULL;
3951 if (!type_switch.name.empty())
3953 Variable* switch_var = new Variable(NULL, type_switch.expr, false, false,
3954 false, type_switch.location);
3955 switch_no = this->gogo_->add_variable(type_switch.name, switch_var);
3958 Type_switch_statement* statement =
3959 Statement::make_type_switch_statement(switch_no,
3965 this->push_break_statement(statement, label);
3967 Type_case_clauses* case_clauses = new Type_case_clauses();
3968 bool saw_default = false;
3969 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
3971 if (this->peek_token()->is_eof())
3973 error_at(this->location(), "missing %<}%>");
3976 this->type_case_clause(switch_no, case_clauses, &saw_default);
3978 this->advance_token();
3980 statement->add_clauses(case_clauses);
3982 this->pop_break_statement();
3987 // TypeCaseClause = TypeSwitchCase ":" [ StatementList ] .
3990 Parse::type_case_clause(Named_object* switch_no, Type_case_clauses* clauses,
3993 source_location location = this->location();
3995 std::vector<Type*> types;
3996 bool is_default = false;
3997 this->type_switch_case(&types, &is_default);
3999 if (!this->peek_token()->is_op(OPERATOR_COLON))
4000 error_at(this->location(), "expected %<:%>");
4002 this->advance_token();
4004 Block* statements = NULL;
4005 if (this->statement_list_may_start_here())
4007 this->gogo_->start_block(this->location());
4008 if (switch_no != NULL && types.size() == 1)
4010 Type* type = types.front();
4011 Expression* init = Expression::make_var_reference(switch_no,
4013 init = Expression::make_type_guard(init, type, location);
4014 Variable* v = new Variable(type, init, false, false, false,
4016 v->set_is_type_switch_var();
4017 this->gogo_->add_variable(switch_no->name(), v);
4019 this->statement_list();
4020 statements = this->gogo_->finish_block(this->location());
4023 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH))
4025 error_at(this->location(),
4026 "fallthrough is not permitted in a type switch");
4027 if (this->advance_token()->is_op(OPERATOR_SEMICOLON))
4028 this->advance_token();
4033 gcc_assert(types.empty());
4036 error_at(location, "multiple defaults in type switch");
4039 *saw_default = true;
4040 clauses->add(NULL, false, true, statements, location);
4042 else if (!types.empty())
4044 for (std::vector<Type*>::const_iterator p = types.begin();
4045 p + 1 != types.end();
4047 clauses->add(*p, true, false, NULL, location);
4048 clauses->add(types.back(), false, false, statements, location);
4051 clauses->add(Type::make_error_type(), false, false, statements, location);
4054 // TypeSwitchCase = "case" type | "default"
4056 // We accept a comma separated list of types.
4059 Parse::type_switch_case(std::vector<Type*>* types, bool* is_default)
4061 const Token* token = this->peek_token();
4062 if (token->is_keyword(KEYWORD_CASE))
4064 this->advance_token();
4067 Type* t = this->type();
4068 if (!t->is_error_type())
4069 types->push_back(t);
4070 if (!this->peek_token()->is_op(OPERATOR_COMMA))
4072 this->advance_token();
4075 else if (token->is_keyword(KEYWORD_DEFAULT))
4077 this->advance_token();
4082 error_at(this->location(), "expected %<case%> or %<default%>");
4083 if (!token->is_op(OPERATOR_RCURLY))
4084 this->advance_token();
4088 // SelectStat = "select" "{" { CommClause } "}" .
4091 Parse::select_stat(const Label* label)
4093 gcc_assert(this->peek_token()->is_keyword(KEYWORD_SELECT));
4094 source_location location = this->location();
4095 const Token* token = this->advance_token();
4097 if (!token->is_op(OPERATOR_LCURLY))
4099 source_location token_loc = token->location();
4100 if (token->is_op(OPERATOR_SEMICOLON)
4101 && this->advance_token()->is_op(OPERATOR_LCURLY))
4102 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
4105 error_at(this->location(), "expected %<{%>");
4109 this->advance_token();
4111 Select_statement* statement = Statement::make_select_statement(location);
4113 this->push_break_statement(statement, label);
4115 Select_clauses* select_clauses = new Select_clauses();
4116 bool saw_default = false;
4117 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
4119 if (this->peek_token()->is_eof())
4121 error_at(this->location(), "expected %<}%>");
4124 this->comm_clause(select_clauses, &saw_default);
4127 this->advance_token();
4129 statement->add_clauses(select_clauses);
4131 this->pop_break_statement();
4133 this->gogo_->add_statement(statement);
4136 // CommClause = CommCase [ StatementList ] .
4139 Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
4141 source_location location = this->location();
4142 bool is_send = false;
4143 Expression* channel = NULL;
4144 Expression* val = NULL;
4145 std::string varname;
4146 bool is_default = false;
4147 bool got_case = this->comm_case(&is_send, &channel, &val, &varname,
4150 Block* statements = NULL;
4151 Named_object* var = NULL;
4152 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
4153 this->advance_token();
4154 else if (this->statement_list_may_start_here())
4156 this->gogo_->start_block(this->location());
4158 if (!varname.empty())
4160 // FIXME: LOCATION is slightly wrong here.
4161 Variable* v = new Variable(NULL, channel, false, false, false,
4163 v->set_type_from_chan_element();
4164 var = this->gogo_->add_variable(varname, v);
4167 this->statement_list();
4168 statements = this->gogo_->finish_block(this->location());
4175 error_at(location, "multiple defaults in select");
4178 *saw_default = true;
4182 clauses->add(is_send, channel, val, var, is_default, statements, location);
4185 // CommCase = ( "default" | ( "case" ( SendExpr | RecvExpr) ) ) ":" .
4188 Parse::comm_case(bool* is_send, Expression** channel, Expression** val,
4189 std::string* varname, bool* is_default)
4191 const Token* token = this->peek_token();
4192 if (token->is_keyword(KEYWORD_DEFAULT))
4194 this->advance_token();
4197 else if (token->is_keyword(KEYWORD_CASE))
4199 this->advance_token();
4200 if (!this->send_or_recv_expr(is_send, channel, val, varname))
4205 error_at(this->location(), "expected %<case%> or %<default%>");
4206 if (!token->is_op(OPERATOR_RCURLY))
4207 this->advance_token();
4211 if (!this->peek_token()->is_op(OPERATOR_COLON))
4213 error_at(this->location(), "expected colon");
4217 this->advance_token();
4222 // SendExpr = Expression "<-" Expression .
4223 // RecvExpr = [ Expression ( "=" | ":=" ) ] "<-" Expression .
4226 Parse::send_or_recv_expr(bool* is_send, Expression** channel, Expression** val,
4227 std::string* varname)
4229 const Token* token = this->peek_token();
4230 source_location location = token->location();
4231 if (token->is_identifier())
4233 std::string recv_var = token->identifier();
4234 bool is_var_exported = token->is_identifier_exported();
4235 if (!this->advance_token()->is_op(OPERATOR_COLONEQ))
4236 this->unget_token(Token::make_identifier_token(recv_var,
4241 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4243 error_at(this->location(), "expected %<<-%>");
4247 *varname = this->gogo_->pack_hidden_name(recv_var, is_var_exported);
4248 this->advance_token();
4249 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4254 if (this->peek_token()->is_op(OPERATOR_CHANOP))
4257 this->advance_token();
4258 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4262 Expression* left = this->expression(PRECEDENCE_CHANOP, true, true, NULL);
4264 if (this->peek_token()->is_op(OPERATOR_EQ))
4266 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4268 error_at(this->location(), "missing %<<-%>");
4273 this->advance_token();
4274 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4276 else if (this->peek_token()->is_op(OPERATOR_CHANOP))
4279 *channel = this->verify_not_sink(left);
4280 this->advance_token();
4281 *val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4285 error_at(this->location(), "expected %<<-%> or %<=%>");
4293 // ForStat = "for" [ Condition | ForClause | RangeClause ] Block .
4294 // Condition = Expression .
4297 Parse::for_stat(const Label* label)
4299 gcc_assert(this->peek_token()->is_keyword(KEYWORD_FOR));
4300 source_location location = this->location();
4301 const Token* token = this->advance_token();
4303 // Open a block to hold any variables defined in the init statement
4304 // of the for statement.
4305 this->gogo_->start_block(location);
4308 Expression* cond = NULL;
4310 Range_clause range_clause;
4312 if (!token->is_op(OPERATOR_LCURLY))
4314 if (token->is_keyword(KEYWORD_VAR))
4316 error_at(this->location(),
4317 "var declaration not allowed in for initializer");
4321 if (token->is_op(OPERATOR_SEMICOLON))
4322 this->for_clause(&cond, &post);
4325 // We might be looking at a Condition, an InitStat, or a
4327 cond = this->simple_stat(false, true, &range_clause, NULL);
4328 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
4330 if (cond == NULL && !range_clause.found)
4331 error_at(this->location(), "parse error in for statement");
4335 if (range_clause.found)
4336 error_at(this->location(), "parse error after range clause");
4340 // COND is actually an expression statement for
4341 // InitStat at the start of a ForClause.
4342 this->expression_stat(cond);
4346 this->for_clause(&cond, &post);
4351 // Build the For_statement and note that it is the current target
4352 // for break and continue statements.
4354 For_statement* sfor;
4355 For_range_statement* srange;
4357 if (!range_clause.found)
4359 sfor = Statement::make_for_statement(init, cond, post, location);
4365 srange = Statement::make_for_range_statement(range_clause.index,
4373 this->push_break_statement(s, label);
4374 this->push_continue_statement(s, label);
4376 // Gather the block of statements in the loop and add them to the
4379 this->gogo_->start_block(this->location());
4380 source_location end_loc = this->block();
4381 Block* statements = this->gogo_->finish_block(end_loc);
4384 sfor->add_statements(statements);
4386 srange->add_statements(statements);
4388 // This is no longer the break/continue target.
4389 this->pop_break_statement();
4390 this->pop_continue_statement();
4392 // Add the For_statement to the list of statements, and close out
4393 // the block we started to hold any variables defined in the for
4396 this->gogo_->add_statement(s);
4398 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
4402 // ForClause = [ InitStat ] ";" [ Condition ] ";" [ PostStat ] .
4403 // InitStat = SimpleStat .
4404 // PostStat = SimpleStat .
4406 // We have already read InitStat at this point.
4409 Parse::for_clause(Expression** cond, Block** post)
4411 gcc_assert(this->peek_token()->is_op(OPERATOR_SEMICOLON));
4412 this->advance_token();
4413 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
4415 else if (this->peek_token()->is_op(OPERATOR_LCURLY))
4417 error_at(this->location(),
4418 "unexpected semicolon or newline before %<{%>");
4424 *cond = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4425 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
4426 error_at(this->location(), "expected semicolon");
4428 this->advance_token();
4430 if (this->peek_token()->is_op(OPERATOR_LCURLY))
4434 this->gogo_->start_block(this->location());
4435 this->simple_stat(false, false, NULL, NULL);
4436 *post = this->gogo_->finish_block(this->location());
4440 // RangeClause = IdentifierList ( "=" | ":=" ) "range" Expression .
4442 // This is the := version. It is called with a list of identifiers.
4445 Parse::range_clause_decl(const Typed_identifier_list* til,
4446 Range_clause* p_range_clause)
4448 gcc_assert(this->peek_token()->is_keyword(KEYWORD_RANGE));
4449 source_location location = this->location();
4451 p_range_clause->found = true;
4453 gcc_assert(til->size() >= 1);
4454 if (til->size() > 2)
4455 error_at(this->location(), "too many variables for range clause");
4457 this->advance_token();
4458 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, false, NULL);
4459 p_range_clause->range = expr;
4461 bool any_new = false;
4463 const Typed_identifier* pti = &til->front();
4464 Named_object* no = this->init_var(*pti, NULL, expr, true, true, &any_new);
4465 if (any_new && no->is_variable())
4466 no->var_value()->set_type_from_range_index();
4467 p_range_clause->index = Expression::make_var_reference(no, location);
4469 if (til->size() == 1)
4470 p_range_clause->value = NULL;
4474 bool is_new = false;
4475 no = this->init_var(*pti, NULL, expr, true, true, &is_new);
4476 if (is_new && no->is_variable())
4477 no->var_value()->set_type_from_range_value();
4480 p_range_clause->value = Expression::make_var_reference(no, location);
4484 error_at(location, "variables redeclared but no variable is new");
4487 // The = version of RangeClause. This is called with a list of
4491 Parse::range_clause_expr(const Expression_list* vals,
4492 Range_clause* p_range_clause)
4494 gcc_assert(this->peek_token()->is_keyword(KEYWORD_RANGE));
4496 p_range_clause->found = true;
4498 gcc_assert(vals->size() >= 1);
4499 if (vals->size() > 2)
4500 error_at(this->location(), "too many variables for range clause");
4502 this->advance_token();
4503 p_range_clause->range = this->expression(PRECEDENCE_NORMAL, false, false,
4506 p_range_clause->index = vals->front();
4507 if (vals->size() == 1)
4508 p_range_clause->value = NULL;
4510 p_range_clause->value = vals->back();
4513 // Push a statement on the break stack.
4516 Parse::push_break_statement(Statement* enclosing, const Label* label)
4518 this->break_stack_.push_back(std::make_pair(enclosing, label));
4521 // Push a statement on the continue stack.
4524 Parse::push_continue_statement(Statement* enclosing, const Label* label)
4526 this->continue_stack_.push_back(std::make_pair(enclosing, label));
4529 // Pop the break stack.
4532 Parse::pop_break_statement()
4534 this->break_stack_.pop_back();
4537 // Pop the continue stack.
4540 Parse::pop_continue_statement()
4542 this->continue_stack_.pop_back();
4545 // Find a break or continue statement given a label name.
4548 Parse::find_bc_statement(const Bc_stack* bc_stack, const std::string& label)
4550 for (Bc_stack::const_reverse_iterator p = bc_stack->rbegin();
4551 p != bc_stack->rend();
4553 if (p->second != NULL && p->second->name() == label)
4558 // BreakStat = "break" [ identifier ] .
4563 gcc_assert(this->peek_token()->is_keyword(KEYWORD_BREAK));
4564 source_location location = this->location();
4566 const Token* token = this->advance_token();
4567 Statement* enclosing;
4568 if (!token->is_identifier())
4570 if (this->break_stack_.empty())
4572 error_at(this->location(),
4573 "break statement not within for or switch or select");
4576 enclosing = this->break_stack_.back().first;
4580 enclosing = this->find_bc_statement(&this->break_stack_,
4581 token->identifier());
4582 if (enclosing == NULL)
4584 error_at(token->location(),
4585 ("break label %qs not associated with "
4586 "for or switch or select"),
4587 Gogo::message_name(token->identifier()).c_str());
4588 this->advance_token();
4591 this->advance_token();
4594 Unnamed_label* label;
4595 if (enclosing->classification() == Statement::STATEMENT_FOR)
4596 label = enclosing->for_statement()->break_label();
4597 else if (enclosing->classification() == Statement::STATEMENT_FOR_RANGE)
4598 label = enclosing->for_range_statement()->break_label();
4599 else if (enclosing->classification() == Statement::STATEMENT_SWITCH)
4600 label = enclosing->switch_statement()->break_label();
4601 else if (enclosing->classification() == Statement::STATEMENT_TYPE_SWITCH)
4602 label = enclosing->type_switch_statement()->break_label();
4603 else if (enclosing->classification() == Statement::STATEMENT_SELECT)
4604 label = enclosing->select_statement()->break_label();
4608 this->gogo_->add_statement(Statement::make_break_statement(label,
4612 // ContinueStat = "continue" [ identifier ] .
4615 Parse::continue_stat()
4617 gcc_assert(this->peek_token()->is_keyword(KEYWORD_CONTINUE));
4618 source_location location = this->location();
4620 const Token* token = this->advance_token();
4621 Statement* enclosing;
4622 if (!token->is_identifier())
4624 if (this->continue_stack_.empty())
4626 error_at(this->location(), "continue statement not within for");
4629 enclosing = this->continue_stack_.back().first;
4633 enclosing = this->find_bc_statement(&this->continue_stack_,
4634 token->identifier());
4635 if (enclosing == NULL)
4637 error_at(token->location(),
4638 "continue label %qs not associated with for",
4639 Gogo::message_name(token->identifier()).c_str());
4640 this->advance_token();
4643 this->advance_token();
4646 Unnamed_label* label;
4647 if (enclosing->classification() == Statement::STATEMENT_FOR)
4648 label = enclosing->for_statement()->continue_label();
4649 else if (enclosing->classification() == Statement::STATEMENT_FOR_RANGE)
4650 label = enclosing->for_range_statement()->continue_label();
4654 this->gogo_->add_statement(Statement::make_continue_statement(label,
4658 // GotoStat = "goto" identifier .
4663 gcc_assert(this->peek_token()->is_keyword(KEYWORD_GOTO));
4664 source_location location = this->location();
4665 const Token* token = this->advance_token();
4666 if (!token->is_identifier())
4667 error_at(this->location(), "expected label for goto");
4670 Label* label = this->gogo_->add_label_reference(token->identifier());
4671 Statement* s = Statement::make_goto_statement(label, location);
4672 this->gogo_->add_statement(s);
4673 this->advance_token();
4677 // PackageClause = "package" PackageName .
4680 Parse::package_clause()
4682 const Token* token = this->peek_token();
4683 source_location location = token->location();
4685 if (!token->is_keyword(KEYWORD_PACKAGE))
4687 error_at(this->location(), "program must start with package clause");
4692 token = this->advance_token();
4693 if (token->is_identifier())
4695 name = token->identifier();
4698 error_at(this->location(), "invalid package name _");
4701 this->advance_token();
4705 error_at(this->location(), "package name must be an identifier");
4709 this->gogo_->set_package_name(name, location);
4712 // ImportDecl = "import" Decl<ImportSpec> .
4715 Parse::import_decl()
4717 gcc_assert(this->peek_token()->is_keyword(KEYWORD_IMPORT));
4718 this->advance_token();
4719 this->decl(&Parse::import_spec, NULL);
4722 // ImportSpec = [ "." | PackageName ] PackageFileName .
4725 Parse::import_spec(void*)
4727 const Token* token = this->peek_token();
4728 source_location location = token->location();
4730 std::string local_name;
4731 bool is_local_name_exported = false;
4732 if (token->is_op(OPERATOR_DOT))
4735 token = this->advance_token();
4737 else if (token->is_identifier())
4739 local_name = token->identifier();
4740 is_local_name_exported = token->is_identifier_exported();
4741 token = this->advance_token();
4744 if (!token->is_string())
4746 error_at(this->location(), "missing import package name");
4750 this->gogo_->import_package(token->string_value(), local_name,
4751 is_local_name_exported, location);
4753 this->advance_token();
4756 // SourceFile = PackageClause ";" { ImportDecl ";" }
4757 // { TopLevelDecl ";" } .
4762 this->package_clause();
4764 const Token* token = this->peek_token();
4765 if (token->is_op(OPERATOR_SEMICOLON))
4766 token = this->advance_token();
4768 error_at(this->location(),
4769 "expected %<;%> or newline after package clause");
4771 while (token->is_keyword(KEYWORD_IMPORT))
4773 this->import_decl();
4774 token = this->peek_token();
4775 if (token->is_op(OPERATOR_SEMICOLON))
4776 token = this->advance_token();
4778 error_at(this->location(),
4779 "expected %<;%> or newline after import declaration");
4782 while (!token->is_eof())
4784 if (this->declaration_may_start_here())
4785 this->declaration();
4788 error_at(this->location(), "expected declaration");
4790 this->advance_token();
4791 while (!this->peek_token()->is_eof()
4792 && !this->peek_token()->is_op(OPERATOR_SEMICOLON)
4793 && !this->peek_token()->is_op(OPERATOR_RCURLY));
4794 if (!this->peek_token()->is_eof()
4795 && !this->peek_token()->is_op(OPERATOR_SEMICOLON))
4796 this->advance_token();
4798 token = this->peek_token();
4799 if (token->is_op(OPERATOR_SEMICOLON))
4800 token = this->advance_token();
4801 else if (!token->is_eof() || !saw_errors())
4803 error_at(this->location(),
4804 "expected %<;%> or newline after top level declaration");
4805 this->skip_past_error(OPERATOR_INVALID);
4810 // Reset the current iota value.
4818 // Return the current iota value.
4826 // Increment the current iota value.
4829 Parse::increment_iota()
4834 // Skip forward to a semicolon or OP. OP will normally be
4835 // OPERATOR_RPAREN or OPERATOR_RCURLY. If we find a semicolon, move
4836 // past it and return. If we find OP, it will be the next token to
4837 // read. Return true if we are OK, false if we found EOF.
4840 Parse::skip_past_error(Operator op)
4842 const Token* token = this->peek_token();
4843 while (!token->is_op(op))
4845 if (token->is_eof())
4847 if (token->is_op(OPERATOR_SEMICOLON))
4849 this->advance_token();
4852 token = this->advance_token();
4857 // Check that an expression is not a sink.
4860 Parse::verify_not_sink(Expression* expr)
4862 if (expr->is_sink_expression())
4864 error_at(expr->location(), "cannot use _ as value");
4865 expr = Expression::make_error(expr->location());