1 // parse.cc -- Go frontend parser.
3 // Copyright 2009 The Go Authors. All rights reserved.
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file.
12 #include "statements.h"
13 #include "expressions.h"
16 // Struct Parse::Enclosing_var_comparison.
18 // Return true if v1 should be considered to be less than v2.
21 Parse::Enclosing_var_comparison::operator()(const Enclosing_var& v1,
22 const Enclosing_var& v2)
24 if (v1.var() == v2.var())
27 const std::string& n1(v1.var()->name());
28 const std::string& n2(v2.var()->name());
29 int i = n1.compare(n2);
35 // If we get here it means that a single nested function refers to
36 // two different variables defined in enclosing functions, and both
37 // variables have the same name. I think this is impossible.
43 Parse::Parse(Lex* lex, Gogo* gogo)
45 token_(Token::make_invalid_token(0)),
46 unget_token_(Token::make_invalid_token(0)),
47 unget_token_valid_(false),
50 continue_stack_(NULL),
56 // Return the current token.
61 if (this->unget_token_valid_)
62 return &this->unget_token_;
63 if (this->token_.is_invalid())
64 this->token_ = this->lex_->next_token();
68 // Advance to the next token and return it.
71 Parse::advance_token()
73 if (this->unget_token_valid_)
75 this->unget_token_valid_ = false;
76 if (!this->token_.is_invalid())
79 this->token_ = this->lex_->next_token();
83 // Push a token back on the input stream.
86 Parse::unget_token(const Token& token)
88 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(this->gogo_, s);
1662 else if (!no->is_sink())
1664 if (no->is_variable())
1665 no->var_value()->add_preinit_statement(this->gogo_, 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(this->gogo_, 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(this->gogo_, s);
1729 else if (!no->is_sink())
1731 if (no->is_variable())
1732 no->var_value()->add_preinit_statement(this->gogo_, s);
1736 Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
1738 dummy->var_value()->add_preinit_statement(this->gogo_, 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(this->gogo_, s);
1795 else if (!no->is_sink())
1797 if (no->is_variable())
1798 no->var_value()->add_preinit_statement(this->gogo_, s);
1802 Named_object* dummy = this->create_dummy_global(type, NULL, location);
1803 dummy->var_value()->add_preinit_statement(this->gogo_, 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 Named_object* no = this->gogo_->add_variable(tid.name(), var);
1852 if (!no->is_variable())
1854 // The name is already defined, so we just gave an error.
1855 return this->gogo_->add_sink();
1860 // Create a dummy global variable to force an initializer to be run in
1861 // the right place. This is used when a sink variable is initialized
1865 Parse::create_dummy_global(Type* type, Expression* init,
1866 source_location location)
1868 if (type == NULL && init == NULL)
1869 type = Type::lookup_bool_type();
1870 Variable* var = new Variable(type, init, true, false, false, location);
1873 snprintf(buf, sizeof buf, "_.%d", count);
1875 return this->gogo_->add_variable(buf, var);
1878 // SimpleVarDecl = identifier ":=" Expression .
1880 // We've already seen the identifier.
1882 // FIXME: We also have to implement
1883 // IdentifierList ":=" ExpressionList
1884 // In order to support both "a, b := 1, 0" and "a, b = 1, 0" we accept
1885 // tuple assignments here as well.
1887 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
1890 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
1891 // guard (var := expr.("type") using the literal keyword "type").
1894 Parse::simple_var_decl_or_assignment(const std::string& name,
1895 source_location location,
1896 Range_clause* p_range_clause,
1897 Type_switch* p_type_switch)
1899 Typed_identifier_list til;
1900 til.push_back(Typed_identifier(name, NULL, location));
1902 // We've seen one identifier. If we see a comma now, this could be
1904 if (this->peek_token()->is_op(OPERATOR_COMMA))
1906 gcc_assert(p_type_switch == NULL);
1909 const Token* token = this->advance_token();
1910 if (!token->is_identifier())
1913 std::string id = token->identifier();
1914 bool is_id_exported = token->is_identifier_exported();
1915 source_location id_location = token->location();
1917 token = this->advance_token();
1918 if (!token->is_op(OPERATOR_COMMA))
1920 if (token->is_op(OPERATOR_COLONEQ))
1922 id = this->gogo_->pack_hidden_name(id, is_id_exported);
1923 til.push_back(Typed_identifier(id, NULL, location));
1926 this->unget_token(Token::make_identifier_token(id,
1932 id = this->gogo_->pack_hidden_name(id, is_id_exported);
1933 til.push_back(Typed_identifier(id, NULL, location));
1936 // We have a comma separated list of identifiers in TIL. If the
1937 // next token is COLONEQ, then this is a simple var decl, and we
1938 // have the complete list of identifiers. If the next token is
1939 // not COLONEQ, then the only valid parse is a tuple assignment.
1940 // The list of identifiers we have so far is really a list of
1941 // expressions. There are more expressions following.
1943 if (!this->peek_token()->is_op(OPERATOR_COLONEQ))
1945 Expression_list* exprs = new Expression_list;
1946 for (Typed_identifier_list::const_iterator p = til.begin();
1949 exprs->push_back(this->id_to_expression(p->name(),
1952 Expression_list* more_exprs = this->expression_list(NULL, true);
1953 for (Expression_list::const_iterator p = more_exprs->begin();
1954 p != more_exprs->end();
1956 exprs->push_back(*p);
1959 this->tuple_assignment(exprs, p_range_clause);
1964 gcc_assert(this->peek_token()->is_op(OPERATOR_COLONEQ));
1965 const Token* token = this->advance_token();
1967 if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
1969 this->range_clause_decl(&til, p_range_clause);
1973 Expression_list* init;
1974 if (p_type_switch == NULL)
1975 init = this->expression_list(NULL, false);
1978 bool is_type_switch = false;
1979 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true,
1983 p_type_switch->found = true;
1984 p_type_switch->name = name;
1985 p_type_switch->location = location;
1986 p_type_switch->expr = expr;
1990 if (!this->peek_token()->is_op(OPERATOR_COMMA))
1992 init = new Expression_list();
1993 init->push_back(expr);
1997 this->advance_token();
1998 init = this->expression_list(expr, false);
2002 this->init_vars(&til, NULL, init, true, location);
2005 // FunctionDecl = "func" identifier Signature [ Block ] .
2006 // MethodDecl = "func" Receiver identifier Signature [ Block ] .
2009 // FunctionDecl = "func" identifier Signature
2010 // __asm__ "(" string_lit ")" .
2011 // This extension means a function whose real name is the identifier
2015 Parse::function_decl()
2017 gcc_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
2018 source_location location = this->location();
2019 const Token* token = this->advance_token();
2021 Typed_identifier* rec = NULL;
2022 if (token->is_op(OPERATOR_LPAREN))
2024 rec = this->receiver();
2025 token = this->peek_token();
2028 if (!token->is_identifier())
2030 error_at(this->location(), "expected function name");
2035 this->gogo_->pack_hidden_name(token->identifier(),
2036 token->is_identifier_exported());
2038 this->advance_token();
2040 Function_type* fntype = this->signature(rec, this->location());
2044 Named_object* named_object = NULL;
2046 if (this->peek_token()->is_keyword(KEYWORD_ASM))
2048 if (!this->advance_token()->is_op(OPERATOR_LPAREN))
2050 error_at(this->location(), "expected %<(%>");
2053 token = this->advance_token();
2054 if (!token->is_string())
2056 error_at(this->location(), "expected string");
2059 std::string asm_name = token->string_value();
2060 if (!this->advance_token()->is_op(OPERATOR_RPAREN))
2062 error_at(this->location(), "expected %<)%>");
2065 this->advance_token();
2066 if (!Gogo::is_sink_name(name))
2068 named_object = this->gogo_->declare_function(name, fntype, location);
2069 if (named_object->is_function_declaration())
2070 named_object->func_declaration_value()->set_asm_name(asm_name);
2074 // Check for the easy error of a newline before the opening brace.
2075 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
2077 source_location semi_loc = this->location();
2078 if (this->advance_token()->is_op(OPERATOR_LCURLY))
2079 error_at(this->location(),
2080 "unexpected semicolon or newline before %<{%>");
2082 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
2086 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
2088 if (named_object == NULL && !Gogo::is_sink_name(name))
2089 this->gogo_->declare_function(name, fntype, location);
2093 this->gogo_->start_function(name, fntype, true, location);
2094 source_location end_loc = this->block();
2095 this->gogo_->finish_function(end_loc);
2099 // Receiver = "(" [ identifier ] [ "*" ] BaseTypeName ")" .
2100 // BaseTypeName = identifier .
2105 gcc_assert(this->peek_token()->is_op(OPERATOR_LPAREN));
2108 const Token* token = this->advance_token();
2109 source_location location = token->location();
2110 if (!token->is_op(OPERATOR_MULT))
2112 if (!token->is_identifier())
2114 error_at(this->location(), "method has no receiver");
2115 while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
2116 token = this->advance_token();
2117 if (!token->is_eof())
2118 this->advance_token();
2121 name = token->identifier();
2122 bool is_exported = token->is_identifier_exported();
2123 token = this->advance_token();
2124 if (!token->is_op(OPERATOR_DOT) && !token->is_op(OPERATOR_RPAREN))
2126 // An identifier followed by something other than a dot or a
2127 // right parenthesis must be a receiver name followed by a
2129 name = this->gogo_->pack_hidden_name(name, is_exported);
2133 // This must be a type name.
2134 this->unget_token(Token::make_identifier_token(name, is_exported,
2136 token = this->peek_token();
2141 // Here the receiver name is in NAME (it is empty if the receiver is
2142 // unnamed) and TOKEN is the first token in the type.
2144 bool is_pointer = false;
2145 if (token->is_op(OPERATOR_MULT))
2148 token = this->advance_token();
2151 if (!token->is_identifier())
2153 error_at(this->location(), "expected receiver name or type");
2154 int c = token->is_op(OPERATOR_LPAREN) ? 1 : 0;
2155 while (!token->is_eof())
2157 token = this->advance_token();
2158 if (token->is_op(OPERATOR_LPAREN))
2160 else if (token->is_op(OPERATOR_RPAREN))
2167 if (!token->is_eof())
2168 this->advance_token();
2172 Type* type = this->type_name(true);
2174 if (is_pointer && !type->is_error_type())
2175 type = Type::make_pointer_type(type);
2177 if (this->peek_token()->is_op(OPERATOR_RPAREN))
2178 this->advance_token();
2181 if (this->peek_token()->is_op(OPERATOR_COMMA))
2182 error_at(this->location(), "method has multiple receivers");
2184 error_at(this->location(), "expected %<)%>");
2185 while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
2186 token = this->advance_token();
2187 if (!token->is_eof())
2188 this->advance_token();
2192 return new Typed_identifier(name, type, location);
2195 // Operand = Literal | QualifiedIdent | MethodExpr | "(" Expression ")" .
2196 // Literal = BasicLit | CompositeLit | FunctionLit .
2197 // BasicLit = int_lit | float_lit | imaginary_lit | char_lit | string_lit .
2199 // If MAY_BE_SINK is true, this operand may be "_".
2202 Parse::operand(bool may_be_sink)
2204 const Token* token = this->peek_token();
2206 switch (token->classification())
2208 case Token::TOKEN_IDENTIFIER:
2210 source_location location = token->location();
2211 std::string id = token->identifier();
2212 bool is_exported = token->is_identifier_exported();
2213 std::string packed = this->gogo_->pack_hidden_name(id, is_exported);
2215 Named_object* in_function;
2216 Named_object* named_object = this->gogo_->lookup(packed, &in_function);
2218 Package* package = NULL;
2219 if (named_object != NULL && named_object->is_package())
2221 if (!this->advance_token()->is_op(OPERATOR_DOT)
2222 || !this->advance_token()->is_identifier())
2224 error_at(location, "unexpected reference to package");
2225 return Expression::make_error(location);
2227 package = named_object->package_value();
2228 package->set_used();
2229 id = this->peek_token()->identifier();
2230 is_exported = this->peek_token()->is_identifier_exported();
2231 packed = this->gogo_->pack_hidden_name(id, is_exported);
2232 named_object = package->lookup(packed);
2233 location = this->location();
2234 gcc_assert(in_function == NULL);
2237 this->advance_token();
2239 if (named_object != NULL
2240 && named_object->is_type()
2241 && !named_object->type_value()->is_visible())
2243 gcc_assert(package != NULL);
2244 error_at(location, "invalid reference to hidden type %<%s.%s%>",
2245 Gogo::message_name(package->name()).c_str(),
2246 Gogo::message_name(id).c_str());
2247 return Expression::make_error(location);
2251 if (named_object == NULL)
2253 if (package != NULL)
2255 std::string n1 = Gogo::message_name(package->name());
2256 std::string n2 = Gogo::message_name(id);
2259 ("invalid reference to unexported identifier "
2261 n1.c_str(), n2.c_str());
2264 "reference to undefined identifier %<%s.%s%>",
2265 n1.c_str(), n2.c_str());
2266 return Expression::make_error(location);
2269 named_object = this->gogo_->add_unknown_name(packed, location);
2272 if (in_function != NULL
2273 && in_function != this->gogo_->current_function()
2274 && (named_object->is_variable()
2275 || named_object->is_result_variable()))
2276 return this->enclosing_var_reference(in_function, named_object,
2279 switch (named_object->classification())
2281 case Named_object::NAMED_OBJECT_CONST:
2282 return Expression::make_const_reference(named_object, location);
2283 case Named_object::NAMED_OBJECT_TYPE:
2284 return Expression::make_type(named_object->type_value(), location);
2285 case Named_object::NAMED_OBJECT_TYPE_DECLARATION:
2287 Type* t = Type::make_forward_declaration(named_object);
2288 return Expression::make_type(t, location);
2290 case Named_object::NAMED_OBJECT_VAR:
2291 case Named_object::NAMED_OBJECT_RESULT_VAR:
2292 return Expression::make_var_reference(named_object, location);
2293 case Named_object::NAMED_OBJECT_SINK:
2295 return Expression::make_sink(location);
2298 error_at(location, "cannot use _ as value");
2299 return Expression::make_error(location);
2301 case Named_object::NAMED_OBJECT_FUNC:
2302 case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
2303 return Expression::make_func_reference(named_object, NULL,
2305 case Named_object::NAMED_OBJECT_UNKNOWN:
2306 return Expression::make_unknown_reference(named_object, location);
2313 case Token::TOKEN_STRING:
2314 ret = Expression::make_string(token->string_value(), token->location());
2315 this->advance_token();
2318 case Token::TOKEN_INTEGER:
2319 ret = Expression::make_integer(token->integer_value(), NULL,
2321 this->advance_token();
2324 case Token::TOKEN_FLOAT:
2325 ret = Expression::make_float(token->float_value(), NULL,
2327 this->advance_token();
2330 case Token::TOKEN_IMAGINARY:
2333 mpfr_init_set_ui(zero, 0, GMP_RNDN);
2334 ret = Expression::make_complex(&zero, token->imaginary_value(),
2335 NULL, token->location());
2337 this->advance_token();
2341 case Token::TOKEN_KEYWORD:
2342 switch (token->keyword())
2345 return this->function_lit();
2347 case KEYWORD_INTERFACE:
2349 case KEYWORD_STRUCT:
2351 source_location location = token->location();
2352 return Expression::make_type(this->type(), location);
2359 case Token::TOKEN_OPERATOR:
2360 if (token->is_op(OPERATOR_LPAREN))
2362 this->advance_token();
2363 ret = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2364 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2365 error_at(this->location(), "missing %<)%>");
2367 this->advance_token();
2370 else if (token->is_op(OPERATOR_LSQUARE))
2372 // Here we call array_type directly, as this is the only
2373 // case where an ellipsis is permitted for an array type.
2374 source_location location = token->location();
2375 return Expression::make_type(this->array_type(true), location);
2383 error_at(this->location(), "expected operand");
2384 return Expression::make_error(this->location());
2387 // Handle a reference to a variable in an enclosing function. We add
2388 // it to a list of such variables. We return a reference to a field
2389 // in a struct which will be passed on the static chain when calling
2390 // the current function.
2393 Parse::enclosing_var_reference(Named_object* in_function, Named_object* var,
2394 source_location location)
2396 gcc_assert(var->is_variable() || var->is_result_variable());
2398 Named_object* this_function = this->gogo_->current_function();
2399 Named_object* closure = this_function->func_value()->closure_var();
2401 Enclosing_var ev(var, in_function, this->enclosing_vars_.size());
2402 std::pair<Enclosing_vars::iterator, bool> ins =
2403 this->enclosing_vars_.insert(ev);
2406 // This is a variable we have not seen before. Add a new field
2407 // to the closure type.
2408 this_function->func_value()->add_closure_field(var, location);
2411 Expression* closure_ref = Expression::make_var_reference(closure,
2413 closure_ref = Expression::make_unary(OPERATOR_MULT, closure_ref, location);
2415 // The closure structure holds pointers to the variables, so we need
2416 // to introduce an indirection.
2417 Expression* e = Expression::make_field_reference(closure_ref,
2420 e = Expression::make_unary(OPERATOR_MULT, e, location);
2424 // CompositeLit = LiteralType LiteralValue .
2425 // LiteralType = StructType | ArrayType | "[" "..." "]" ElementType |
2426 // SliceType | MapType | TypeName .
2427 // LiteralValue = "{" [ ElementList [ "," ] ] "}" .
2428 // ElementList = Element { "," Element } .
2429 // Element = [ Key ":" ] Value .
2430 // Key = Expression .
2431 // Value = Expression | LiteralValue .
2433 // We have already seen the type if there is one, and we are now
2434 // looking at the LiteralValue. The case "[" "..." "]" ElementType
2435 // will be seen here as an array type whose length is "nil". The
2436 // DEPTH parameter is non-zero if this is an embedded composite
2437 // literal and the type was omitted. It gives the number of steps up
2438 // to the type which was provided. E.g., in [][]int{{1}} it will be
2439 // 1. In [][][]int{{{1}}} it will be 2.
2442 Parse::composite_lit(Type* type, int depth, source_location location)
2444 gcc_assert(this->peek_token()->is_op(OPERATOR_LCURLY));
2445 this->advance_token();
2447 if (this->peek_token()->is_op(OPERATOR_RCURLY))
2449 this->advance_token();
2450 return Expression::make_composite_literal(type, depth, false, NULL,
2454 bool has_keys = false;
2455 Expression_list* vals = new Expression_list;
2459 bool is_type_omitted = false;
2461 const Token* token = this->peek_token();
2463 if (!token->is_op(OPERATOR_LCURLY))
2464 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2467 // This must be a composite literal inside another composite
2468 // literal, with the type omitted for the inner one.
2469 val = this->composite_lit(type, depth + 1, token->location());
2470 is_type_omitted = true;
2473 token = this->peek_token();
2474 if (!token->is_op(OPERATOR_COLON))
2477 vals->push_back(NULL);
2481 if (is_type_omitted && !val->is_error_expression())
2483 error_at(this->location(), "unexpected %<:%>");
2484 val = Expression::make_error(this->location());
2487 this->advance_token();
2489 if (!has_keys && !vals->empty())
2491 Expression_list* newvals = new Expression_list;
2492 for (Expression_list::const_iterator p = vals->begin();
2496 newvals->push_back(NULL);
2497 newvals->push_back(*p);
2504 if (val->unknown_expression() != NULL)
2505 val->unknown_expression()->set_is_composite_literal_key();
2507 vals->push_back(val);
2509 if (!token->is_op(OPERATOR_LCURLY))
2510 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2513 // This must be a composite literal inside another
2514 // composite literal, with the type omitted for the
2516 val = this->composite_lit(type, depth + 1, token->location());
2519 token = this->peek_token();
2522 vals->push_back(val);
2524 if (token->is_op(OPERATOR_COMMA))
2526 if (this->advance_token()->is_op(OPERATOR_RCURLY))
2528 this->advance_token();
2532 else if (token->is_op(OPERATOR_RCURLY))
2534 this->advance_token();
2539 error_at(this->location(), "expected %<,%> or %<}%>");
2542 while (!token->is_eof()
2543 && (depth > 0 || !token->is_op(OPERATOR_RCURLY)))
2545 if (token->is_op(OPERATOR_LCURLY))
2547 else if (token->is_op(OPERATOR_RCURLY))
2549 token = this->advance_token();
2551 if (token->is_op(OPERATOR_RCURLY))
2552 this->advance_token();
2554 return Expression::make_error(location);
2558 return Expression::make_composite_literal(type, depth, has_keys, vals,
2562 // FunctionLit = "func" Signature Block .
2565 Parse::function_lit()
2567 source_location location = this->location();
2568 gcc_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
2569 this->advance_token();
2571 Enclosing_vars hold_enclosing_vars;
2572 hold_enclosing_vars.swap(this->enclosing_vars_);
2574 Function_type* type = this->signature(NULL, location);
2576 type = Type::make_function_type(NULL, NULL, NULL, location);
2578 // For a function literal, the next token must be a '{'. If we
2579 // don't see that, then we may have a type expression.
2580 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
2581 return Expression::make_type(type, location);
2583 Bc_stack* hold_break_stack = this->break_stack_;
2584 Bc_stack* hold_continue_stack = this->continue_stack_;
2585 this->break_stack_ = NULL;
2586 this->continue_stack_ = NULL;
2588 Named_object* no = this->gogo_->start_function("", type, true, location);
2590 source_location end_loc = this->block();
2592 this->gogo_->finish_function(end_loc);
2594 if (this->break_stack_ != NULL)
2595 delete this->break_stack_;
2596 if (this->continue_stack_ != NULL)
2597 delete this->continue_stack_;
2598 this->break_stack_ = hold_break_stack;
2599 this->continue_stack_ = hold_continue_stack;
2601 hold_enclosing_vars.swap(this->enclosing_vars_);
2603 Expression* closure = this->create_closure(no, &hold_enclosing_vars,
2606 return Expression::make_func_reference(no, closure, location);
2609 // Create a closure for the nested function FUNCTION. This is based
2610 // on ENCLOSING_VARS, which is a list of all variables defined in
2611 // enclosing functions and referenced from FUNCTION. A closure is the
2612 // address of a struct which contains the addresses of all the
2613 // referenced variables. This returns NULL if no closure is required.
2616 Parse::create_closure(Named_object* function, Enclosing_vars* enclosing_vars,
2617 source_location location)
2619 if (enclosing_vars->empty())
2622 // Get the variables in order by their field index.
2624 size_t enclosing_var_count = enclosing_vars->size();
2625 std::vector<Enclosing_var> ev(enclosing_var_count);
2626 for (Enclosing_vars::const_iterator p = enclosing_vars->begin();
2627 p != enclosing_vars->end();
2629 ev[p->index()] = *p;
2631 // Build an initializer for a composite literal of the closure's
2634 Named_object* enclosing_function = this->gogo_->current_function();
2635 Expression_list* initializer = new Expression_list;
2636 for (size_t i = 0; i < enclosing_var_count; ++i)
2638 gcc_assert(ev[i].index() == i);
2639 Named_object* var = ev[i].var();
2641 if (ev[i].in_function() == enclosing_function)
2642 ref = Expression::make_var_reference(var, location);
2644 ref = this->enclosing_var_reference(ev[i].in_function(), var,
2646 Expression* refaddr = Expression::make_unary(OPERATOR_AND, ref,
2648 initializer->push_back(refaddr);
2651 Named_object* closure_var = function->func_value()->closure_var();
2652 Struct_type* st = closure_var->var_value()->type()->deref()->struct_type();
2653 Expression* cv = Expression::make_struct_composite_literal(st, initializer,
2655 return Expression::make_heap_composite(cv, location);
2658 // PrimaryExpr = Operand { Selector | Index | Slice | TypeGuard | Call } .
2660 // If MAY_BE_SINK is true, this expression may be "_".
2662 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
2665 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2666 // guard (var := expr.("type") using the literal keyword "type").
2669 Parse::primary_expr(bool may_be_sink, bool may_be_composite_lit,
2670 bool* is_type_switch)
2672 source_location start_loc = this->location();
2673 bool is_parenthesized = this->peek_token()->is_op(OPERATOR_LPAREN);
2675 Expression* ret = this->operand(may_be_sink);
2677 // An unknown name followed by a curly brace must be a composite
2678 // literal, and the unknown name must be a type.
2679 if (may_be_composite_lit
2680 && !is_parenthesized
2681 && ret->unknown_expression() != NULL
2682 && this->peek_token()->is_op(OPERATOR_LCURLY))
2684 Named_object* no = ret->unknown_expression()->named_object();
2685 Type* type = Type::make_forward_declaration(no);
2686 ret = Expression::make_type(type, ret->location());
2689 // We handle composite literals and type casts here, as it is the
2690 // easiest way to handle types which are in parentheses, as in
2692 if (ret->is_type_expression())
2694 if (this->peek_token()->is_op(OPERATOR_LCURLY))
2696 if (is_parenthesized)
2698 "cannot parenthesize type in composite literal");
2699 ret = this->composite_lit(ret->type(), 0, ret->location());
2701 else if (this->peek_token()->is_op(OPERATOR_LPAREN))
2703 source_location loc = this->location();
2704 this->advance_token();
2705 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true,
2707 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2708 error_at(this->location(), "expected %<)%>");
2710 this->advance_token();
2711 if (expr->is_error_expression())
2713 ret = Expression::make_cast(ret->type(), expr, loc);
2719 const Token* token = this->peek_token();
2720 if (token->is_op(OPERATOR_LPAREN))
2721 ret = this->call(this->verify_not_sink(ret));
2722 else if (token->is_op(OPERATOR_DOT))
2724 ret = this->selector(this->verify_not_sink(ret), is_type_switch);
2725 if (is_type_switch != NULL && *is_type_switch)
2728 else if (token->is_op(OPERATOR_LSQUARE))
2729 ret = this->index(this->verify_not_sink(ret));
2737 // Selector = "." identifier .
2738 // TypeGuard = "." "(" QualifiedIdent ")" .
2740 // Note that Operand can expand to QualifiedIdent, which contains a
2741 // ".". That is handled directly in operand when it sees a package
2744 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2745 // guard (var := expr.("type") using the literal keyword "type").
2748 Parse::selector(Expression* left, bool* is_type_switch)
2750 gcc_assert(this->peek_token()->is_op(OPERATOR_DOT));
2751 source_location location = this->location();
2753 const Token* token = this->advance_token();
2754 if (token->is_identifier())
2756 // This could be a field in a struct, or a method in an
2757 // interface, or a method associated with a type. We can't know
2758 // which until we have seen all the types.
2760 this->gogo_->pack_hidden_name(token->identifier(),
2761 token->is_identifier_exported());
2762 if (token->identifier() == "_")
2764 error_at(this->location(), "invalid use of %<_%>");
2765 name = this->gogo_->pack_hidden_name("blank", false);
2767 this->advance_token();
2768 return Expression::make_selector(left, name, location);
2770 else if (token->is_op(OPERATOR_LPAREN))
2772 this->advance_token();
2774 if (!this->peek_token()->is_keyword(KEYWORD_TYPE))
2775 type = this->type();
2778 if (is_type_switch != NULL)
2779 *is_type_switch = true;
2782 error_at(this->location(),
2783 "use of %<.(type)%> outside type switch");
2784 type = Type::make_error_type();
2786 this->advance_token();
2788 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2789 error_at(this->location(), "missing %<)%>");
2791 this->advance_token();
2792 if (is_type_switch != NULL && *is_type_switch)
2794 return Expression::make_type_guard(left, type, location);
2798 error_at(this->location(), "expected identifier or %<(%>");
2803 // Index = "[" Expression "]" .
2804 // Slice = "[" Expression ":" [ Expression ] "]" .
2807 Parse::index(Expression* expr)
2809 source_location location = this->location();
2810 gcc_assert(this->peek_token()->is_op(OPERATOR_LSQUARE));
2811 this->advance_token();
2814 if (!this->peek_token()->is_op(OPERATOR_COLON))
2815 start = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2819 mpz_init_set_ui(zero, 0);
2820 start = Expression::make_integer(&zero, NULL, location);
2824 Expression* end = NULL;
2825 if (this->peek_token()->is_op(OPERATOR_COLON))
2827 // We use nil to indicate a missing high expression.
2828 if (this->advance_token()->is_op(OPERATOR_RSQUARE))
2829 end = Expression::make_nil(this->location());
2831 end = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2833 if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
2834 error_at(this->location(), "missing %<]%>");
2836 this->advance_token();
2837 return Expression::make_index(expr, start, end, location);
2840 // Call = "(" [ ArgumentList [ "," ] ] ")" .
2841 // ArgumentList = ExpressionList [ "..." ] .
2844 Parse::call(Expression* func)
2846 gcc_assert(this->peek_token()->is_op(OPERATOR_LPAREN));
2847 Expression_list* args = NULL;
2848 bool is_varargs = false;
2849 const Token* token = this->advance_token();
2850 if (!token->is_op(OPERATOR_RPAREN))
2852 args = this->expression_list(NULL, false);
2853 token = this->peek_token();
2854 if (token->is_op(OPERATOR_ELLIPSIS))
2857 token = this->advance_token();
2860 if (token->is_op(OPERATOR_COMMA))
2861 token = this->advance_token();
2862 if (!token->is_op(OPERATOR_RPAREN))
2863 error_at(this->location(), "missing %<)%>");
2865 this->advance_token();
2866 if (func->is_error_expression())
2868 return Expression::make_call(func, args, is_varargs, func->location());
2871 // Return an expression for a single unqualified identifier.
2874 Parse::id_to_expression(const std::string& name, source_location location)
2876 Named_object* in_function;
2877 Named_object* named_object = this->gogo_->lookup(name, &in_function);
2878 if (named_object == NULL)
2879 named_object = this->gogo_->add_unknown_name(name, location);
2881 if (in_function != NULL
2882 && in_function != this->gogo_->current_function()
2883 && (named_object->is_variable() || named_object->is_result_variable()))
2884 return this->enclosing_var_reference(in_function, named_object,
2887 switch (named_object->classification())
2889 case Named_object::NAMED_OBJECT_CONST:
2890 return Expression::make_const_reference(named_object, location);
2891 case Named_object::NAMED_OBJECT_VAR:
2892 case Named_object::NAMED_OBJECT_RESULT_VAR:
2893 return Expression::make_var_reference(named_object, location);
2894 case Named_object::NAMED_OBJECT_SINK:
2895 return Expression::make_sink(location);
2896 case Named_object::NAMED_OBJECT_FUNC:
2897 case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
2898 return Expression::make_func_reference(named_object, NULL, location);
2899 case Named_object::NAMED_OBJECT_UNKNOWN:
2900 return Expression::make_unknown_reference(named_object, location);
2902 error_at(this->location(), "unexpected type of identifier");
2903 return Expression::make_error(location);
2907 // Expression = UnaryExpr { binary_op Expression } .
2909 // PRECEDENCE is the precedence of the current operator.
2911 // If MAY_BE_SINK is true, this expression may be "_".
2913 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
2916 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2917 // guard (var := expr.("type") using the literal keyword "type").
2920 Parse::expression(Precedence precedence, bool may_be_sink,
2921 bool may_be_composite_lit, bool* is_type_switch)
2923 Expression* left = this->unary_expr(may_be_sink, may_be_composite_lit,
2928 if (is_type_switch != NULL && *is_type_switch)
2931 const Token* token = this->peek_token();
2932 if (token->classification() != Token::TOKEN_OPERATOR)
2938 Precedence right_precedence;
2939 switch (token->op())
2942 right_precedence = PRECEDENCE_OROR;
2944 case OPERATOR_ANDAND:
2945 right_precedence = PRECEDENCE_ANDAND;
2948 case OPERATOR_NOTEQ:
2953 right_precedence = PRECEDENCE_RELOP;
2956 case OPERATOR_MINUS:
2959 right_precedence = PRECEDENCE_ADDOP;
2964 case OPERATOR_LSHIFT:
2965 case OPERATOR_RSHIFT:
2967 case OPERATOR_BITCLEAR:
2968 right_precedence = PRECEDENCE_MULOP;
2971 right_precedence = PRECEDENCE_INVALID;
2975 if (right_precedence == PRECEDENCE_INVALID)
2981 Operator op = token->op();
2982 source_location binop_location = token->location();
2984 if (precedence >= right_precedence)
2986 // We've already seen A * B, and we see + C. We want to
2987 // return so that A * B becomes a group.
2991 this->advance_token();
2993 left = this->verify_not_sink(left);
2994 Expression* right = this->expression(right_precedence, false,
2995 may_be_composite_lit,
2997 left = Expression::make_binary(op, left, right, binop_location);
3002 Parse::expression_may_start_here()
3004 const Token* token = this->peek_token();
3005 switch (token->classification())
3007 case Token::TOKEN_INVALID:
3008 case Token::TOKEN_EOF:
3010 case Token::TOKEN_KEYWORD:
3011 switch (token->keyword())
3016 case KEYWORD_STRUCT:
3017 case KEYWORD_INTERFACE:
3022 case Token::TOKEN_IDENTIFIER:
3024 case Token::TOKEN_STRING:
3026 case Token::TOKEN_OPERATOR:
3027 switch (token->op())
3030 case OPERATOR_MINUS:
3034 case OPERATOR_CHANOP:
3036 case OPERATOR_LPAREN:
3037 case OPERATOR_LSQUARE:
3042 case Token::TOKEN_INTEGER:
3043 case Token::TOKEN_FLOAT:
3044 case Token::TOKEN_IMAGINARY:
3051 // UnaryExpr = unary_op UnaryExpr | PrimaryExpr .
3053 // If MAY_BE_SINK is true, this expression may be "_".
3055 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3058 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3059 // guard (var := expr.("type") using the literal keyword "type").
3062 Parse::unary_expr(bool may_be_sink, bool may_be_composite_lit,
3063 bool* is_type_switch)
3065 const Token* token = this->peek_token();
3066 if (token->is_op(OPERATOR_PLUS)
3067 || token->is_op(OPERATOR_MINUS)
3068 || token->is_op(OPERATOR_NOT)
3069 || token->is_op(OPERATOR_XOR)
3070 || token->is_op(OPERATOR_CHANOP)
3071 || token->is_op(OPERATOR_MULT)
3072 || token->is_op(OPERATOR_AND))
3074 source_location location = token->location();
3075 Operator op = token->op();
3076 this->advance_token();
3078 if (op == OPERATOR_CHANOP
3079 && this->peek_token()->is_keyword(KEYWORD_CHAN))
3081 // This is "<- chan" which must be the start of a type.
3082 this->unget_token(Token::make_operator_token(op, location));
3083 return Expression::make_type(this->type(), location);
3086 Expression* expr = this->unary_expr(false, may_be_composite_lit, NULL);
3087 if (expr->is_error_expression())
3089 else if (op == OPERATOR_MULT && expr->is_type_expression())
3090 expr = Expression::make_type(Type::make_pointer_type(expr->type()),
3092 else if (op == OPERATOR_AND && expr->is_composite_literal())
3093 expr = Expression::make_heap_composite(expr, location);
3094 else if (op != OPERATOR_CHANOP)
3095 expr = Expression::make_unary(op, expr, location);
3097 expr = Expression::make_receive(expr, location);
3101 return this->primary_expr(may_be_sink, may_be_composite_lit,
3106 // Declaration | LabeledStmt | SimpleStmt |
3107 // GoStmt | ReturnStmt | BreakStmt | ContinueStmt | GotoStmt |
3108 // FallthroughStmt | Block | IfStmt | SwitchStmt | SelectStmt | ForStmt |
3111 // LABEL is the label of this statement if it has one.
3114 Parse::statement(const Label* label)
3116 const Token* token = this->peek_token();
3117 switch (token->classification())
3119 case Token::TOKEN_KEYWORD:
3121 switch (token->keyword())
3126 this->declaration();
3130 case KEYWORD_STRUCT:
3131 case KEYWORD_INTERFACE:
3132 this->simple_stat(true, false, NULL, NULL);
3136 this->go_or_defer_stat();
3138 case KEYWORD_RETURN:
3139 this->return_stat();
3144 case KEYWORD_CONTINUE:
3145 this->continue_stat();
3153 case KEYWORD_SWITCH:
3154 this->switch_stat(label);
3156 case KEYWORD_SELECT:
3157 this->select_stat(label);
3160 this->for_stat(label);
3163 error_at(this->location(), "expected statement");
3164 this->advance_token();
3170 case Token::TOKEN_IDENTIFIER:
3172 std::string identifier = token->identifier();
3173 bool is_exported = token->is_identifier_exported();
3174 source_location location = token->location();
3175 if (this->advance_token()->is_op(OPERATOR_COLON))
3177 this->advance_token();
3178 this->labeled_stmt(identifier, location);
3182 this->unget_token(Token::make_identifier_token(identifier,
3185 this->simple_stat(true, false, NULL, NULL);
3190 case Token::TOKEN_OPERATOR:
3191 if (token->is_op(OPERATOR_LCURLY))
3193 source_location location = token->location();
3194 this->gogo_->start_block(location);
3195 source_location end_loc = this->block();
3196 this->gogo_->add_block(this->gogo_->finish_block(end_loc),
3199 else if (!token->is_op(OPERATOR_SEMICOLON))
3200 this->simple_stat(true, false, NULL, NULL);
3203 case Token::TOKEN_STRING:
3204 case Token::TOKEN_INTEGER:
3205 case Token::TOKEN_FLOAT:
3206 case Token::TOKEN_IMAGINARY:
3207 this->simple_stat(true, false, NULL, NULL);
3211 error_at(this->location(), "expected statement");
3212 this->advance_token();
3218 Parse::statement_may_start_here()
3220 const Token* token = this->peek_token();
3221 switch (token->classification())
3223 case Token::TOKEN_KEYWORD:
3225 switch (token->keyword())
3232 case KEYWORD_STRUCT:
3233 case KEYWORD_INTERFACE:
3236 case KEYWORD_RETURN:
3238 case KEYWORD_CONTINUE:
3241 case KEYWORD_SWITCH:
3242 case KEYWORD_SELECT:
3252 case Token::TOKEN_IDENTIFIER:
3255 case Token::TOKEN_OPERATOR:
3256 if (token->is_op(OPERATOR_LCURLY)
3257 || token->is_op(OPERATOR_SEMICOLON))
3260 return this->expression_may_start_here();
3262 case Token::TOKEN_STRING:
3263 case Token::TOKEN_INTEGER:
3264 case Token::TOKEN_FLOAT:
3265 case Token::TOKEN_IMAGINARY:
3273 // LabeledStmt = Label ":" Statement .
3274 // Label = identifier .
3277 Parse::labeled_stmt(const std::string& label_name, source_location location)
3279 Label* label = this->gogo_->add_label_definition(label_name, location);
3281 if (this->peek_token()->is_op(OPERATOR_RCURLY))
3283 // This is a label at the end of a block. A program is
3284 // permitted to omit a semicolon here.
3288 if (!this->statement_may_start_here())
3290 error_at(location, "missing statement after label");
3291 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
3296 this->statement(label);
3299 // SimpleStmt = EmptyStmt | ExpressionStmt | SendStmt | IncDecStmt |
3300 // Assignment | ShortVarDecl .
3302 // EmptyStmt was handled in Parse::statement.
3304 // In order to make this work for if and switch statements, if
3305 // RETURN_EXP is true, and we see an ExpressionStat, we return the
3306 // expression rather than adding an expression statement to the
3307 // current block. If we see something other than an ExpressionStat,
3308 // we add the statement and return NULL.
3310 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
3313 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
3314 // guard (var := expr.("type") using the literal keyword "type").
3317 Parse::simple_stat(bool may_be_composite_lit, bool return_exp,
3318 Range_clause* p_range_clause, Type_switch* p_type_switch)
3320 const Token* token = this->peek_token();
3322 // An identifier follow by := is a SimpleVarDecl.
3323 if (token->is_identifier())
3325 std::string identifier = token->identifier();
3326 bool is_exported = token->is_identifier_exported();
3327 source_location location = token->location();
3329 token = this->advance_token();
3330 if (token->is_op(OPERATOR_COLONEQ)
3331 || token->is_op(OPERATOR_COMMA))
3333 identifier = this->gogo_->pack_hidden_name(identifier, is_exported);
3334 this->simple_var_decl_or_assignment(identifier, location,
3336 (token->is_op(OPERATOR_COLONEQ)
3342 this->unget_token(Token::make_identifier_token(identifier, is_exported,
3346 Expression* exp = this->expression(PRECEDENCE_NORMAL, true,
3347 may_be_composite_lit,
3348 (p_type_switch == NULL
3350 : &p_type_switch->found));
3351 if (p_type_switch != NULL && p_type_switch->found)
3353 p_type_switch->name.clear();
3354 p_type_switch->location = exp->location();
3355 p_type_switch->expr = this->verify_not_sink(exp);
3358 token = this->peek_token();
3359 if (token->is_op(OPERATOR_CHANOP))
3360 this->send_stmt(this->verify_not_sink(exp));
3361 else if (token->is_op(OPERATOR_PLUSPLUS)
3362 || token->is_op(OPERATOR_MINUSMINUS))
3363 this->inc_dec_stat(this->verify_not_sink(exp));
3364 else if (token->is_op(OPERATOR_COMMA)
3365 || token->is_op(OPERATOR_EQ))
3366 this->assignment(exp, p_range_clause);
3367 else if (token->is_op(OPERATOR_PLUSEQ)
3368 || token->is_op(OPERATOR_MINUSEQ)
3369 || token->is_op(OPERATOR_OREQ)
3370 || token->is_op(OPERATOR_XOREQ)
3371 || token->is_op(OPERATOR_MULTEQ)
3372 || token->is_op(OPERATOR_DIVEQ)
3373 || token->is_op(OPERATOR_MODEQ)
3374 || token->is_op(OPERATOR_LSHIFTEQ)
3375 || token->is_op(OPERATOR_RSHIFTEQ)
3376 || token->is_op(OPERATOR_ANDEQ)
3377 || token->is_op(OPERATOR_BITCLEAREQ))
3378 this->assignment(this->verify_not_sink(exp), p_range_clause);
3379 else if (return_exp)
3380 return this->verify_not_sink(exp);
3382 this->expression_stat(this->verify_not_sink(exp));
3388 Parse::simple_stat_may_start_here()
3390 return this->expression_may_start_here();
3393 // Parse { Statement ";" } which is used in a few places. The list of
3394 // statements may end with a right curly brace, in which case the
3395 // semicolon may be omitted.
3398 Parse::statement_list()
3400 while (this->statement_may_start_here())
3402 this->statement(NULL);
3403 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3404 this->advance_token();
3405 else if (this->peek_token()->is_op(OPERATOR_RCURLY))
3409 if (!this->peek_token()->is_eof() || !saw_errors())
3410 error_at(this->location(), "expected %<;%> or %<}%> or newline");
3411 if (!this->skip_past_error(OPERATOR_RCURLY))
3418 Parse::statement_list_may_start_here()
3420 return this->statement_may_start_here();
3423 // ExpressionStat = Expression .
3426 Parse::expression_stat(Expression* exp)
3428 exp->discarding_value();
3429 this->gogo_->add_statement(Statement::make_statement(exp));
3432 // SendStmt = Channel "<-" Expression .
3433 // Channel = Expression .
3436 Parse::send_stmt(Expression* channel)
3438 gcc_assert(this->peek_token()->is_op(OPERATOR_CHANOP));
3439 source_location loc = this->location();
3440 this->advance_token();
3441 Expression* val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
3442 Statement* s = Statement::make_send_statement(channel, val, loc);
3443 this->gogo_->add_statement(s);
3446 // IncDecStat = Expression ( "++" | "--" ) .
3449 Parse::inc_dec_stat(Expression* exp)
3451 const Token* token = this->peek_token();
3453 // Lvalue maps require special handling.
3454 if (exp->index_expression() != NULL)
3455 exp->index_expression()->set_is_lvalue();
3457 if (token->is_op(OPERATOR_PLUSPLUS))
3458 this->gogo_->add_statement(Statement::make_inc_statement(exp));
3459 else if (token->is_op(OPERATOR_MINUSMINUS))
3460 this->gogo_->add_statement(Statement::make_dec_statement(exp));
3463 this->advance_token();
3466 // Assignment = ExpressionList assign_op ExpressionList .
3468 // EXP is an expression that we have already parsed.
3470 // If RANGE_CLAUSE is not NULL, then this will recognize a
3474 Parse::assignment(Expression* expr, Range_clause* p_range_clause)
3476 Expression_list* vars;
3477 if (!this->peek_token()->is_op(OPERATOR_COMMA))
3479 vars = new Expression_list();
3480 vars->push_back(expr);
3484 this->advance_token();
3485 vars = this->expression_list(expr, true);
3488 this->tuple_assignment(vars, p_range_clause);
3491 // An assignment statement. LHS is the list of expressions which
3492 // appear on the left hand side.
3494 // If RANGE_CLAUSE is not NULL, then this will recognize a
3498 Parse::tuple_assignment(Expression_list* lhs, Range_clause* p_range_clause)
3500 const Token* token = this->peek_token();
3501 if (!token->is_op(OPERATOR_EQ)
3502 && !token->is_op(OPERATOR_PLUSEQ)
3503 && !token->is_op(OPERATOR_MINUSEQ)
3504 && !token->is_op(OPERATOR_OREQ)
3505 && !token->is_op(OPERATOR_XOREQ)
3506 && !token->is_op(OPERATOR_MULTEQ)
3507 && !token->is_op(OPERATOR_DIVEQ)
3508 && !token->is_op(OPERATOR_MODEQ)
3509 && !token->is_op(OPERATOR_LSHIFTEQ)
3510 && !token->is_op(OPERATOR_RSHIFTEQ)
3511 && !token->is_op(OPERATOR_ANDEQ)
3512 && !token->is_op(OPERATOR_BITCLEAREQ))
3514 error_at(this->location(), "expected assignment operator");
3517 Operator op = token->op();
3518 source_location location = token->location();
3520 token = this->advance_token();
3522 if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
3524 if (op != OPERATOR_EQ)
3525 error_at(this->location(), "range clause requires %<=%>");
3526 this->range_clause_expr(lhs, p_range_clause);
3530 Expression_list* vals = this->expression_list(NULL, false);
3532 // We've parsed everything; check for errors.
3533 if (lhs == NULL || vals == NULL)
3535 for (Expression_list::const_iterator pe = lhs->begin();
3539 if ((*pe)->is_error_expression())
3541 if (op != OPERATOR_EQ && (*pe)->is_sink_expression())
3542 error_at((*pe)->location(), "cannot use _ as value");
3544 for (Expression_list::const_iterator pe = vals->begin();
3548 if ((*pe)->is_error_expression())
3552 // Map expressions act differently when they are lvalues.
3553 for (Expression_list::iterator plv = lhs->begin();
3556 if ((*plv)->index_expression() != NULL)
3557 (*plv)->index_expression()->set_is_lvalue();
3559 Call_expression* call;
3560 Index_expression* map_index;
3561 Receive_expression* receive;
3562 Type_guard_expression* type_guard;
3563 if (lhs->size() == vals->size())
3566 if (lhs->size() > 1)
3568 if (op != OPERATOR_EQ)
3569 error_at(location, "multiple values only permitted with %<=%>");
3570 s = Statement::make_tuple_assignment(lhs, vals, location);
3574 if (op == OPERATOR_EQ)
3575 s = Statement::make_assignment(lhs->front(), vals->front(),
3578 s = Statement::make_assignment_operation(op, lhs->front(),
3579 vals->front(), location);
3583 this->gogo_->add_statement(s);
3585 else if (vals->size() == 1
3586 && (call = (*vals->begin())->call_expression()) != NULL)
3588 if (op != OPERATOR_EQ)
3589 error_at(location, "multiple results only permitted with %<=%>");
3591 vals = new Expression_list;
3592 for (unsigned int i = 0; i < lhs->size(); ++i)
3593 vals->push_back(Expression::make_call_result(call, i));
3594 Statement* s = Statement::make_tuple_assignment(lhs, vals, location);
3595 this->gogo_->add_statement(s);
3597 else if (lhs->size() == 2
3598 && vals->size() == 1
3599 && (map_index = (*vals->begin())->index_expression()) != NULL)
3601 if (op != OPERATOR_EQ)
3602 error_at(location, "two values from map requires %<=%>");
3603 Expression* val = lhs->front();
3604 Expression* present = lhs->back();
3605 Statement* s = Statement::make_tuple_map_assignment(val, present,
3606 map_index, location);
3607 this->gogo_->add_statement(s);
3609 else if (lhs->size() == 1
3610 && vals->size() == 2
3611 && (map_index = lhs->front()->index_expression()) != NULL)
3613 if (op != OPERATOR_EQ)
3614 error_at(location, "assigning tuple to map index requires %<=%>");
3615 Expression* val = vals->front();
3616 Expression* should_set = vals->back();
3617 Statement* s = Statement::make_map_assignment(map_index, val, should_set,
3619 this->gogo_->add_statement(s);
3621 else if (lhs->size() == 2
3622 && vals->size() == 1
3623 && (receive = (*vals->begin())->receive_expression()) != NULL)
3625 if (op != OPERATOR_EQ)
3626 error_at(location, "two values from receive requires %<=%>");
3627 Expression* val = lhs->front();
3628 Expression* success = lhs->back();
3629 Expression* channel = receive->channel();
3630 Statement* s = Statement::make_tuple_receive_assignment(val, success,
3633 this->gogo_->add_statement(s);
3635 else if (lhs->size() == 2
3636 && vals->size() == 1
3637 && (type_guard = (*vals->begin())->type_guard_expression()) != NULL)
3639 if (op != OPERATOR_EQ)
3640 error_at(location, "two values from type guard requires %<=%>");
3641 Expression* val = lhs->front();
3642 Expression* ok = lhs->back();
3643 Expression* expr = type_guard->expr();
3644 Type* type = type_guard->type();
3645 Statement* s = Statement::make_tuple_type_guard_assignment(val, ok,
3648 this->gogo_->add_statement(s);
3652 error_at(location, "number of variables does not match number of values");
3656 // GoStat = "go" Expression .
3657 // DeferStat = "defer" Expression .
3660 Parse::go_or_defer_stat()
3662 gcc_assert(this->peek_token()->is_keyword(KEYWORD_GO)
3663 || this->peek_token()->is_keyword(KEYWORD_DEFER));
3664 bool is_go = this->peek_token()->is_keyword(KEYWORD_GO);
3665 source_location stat_location = this->location();
3666 this->advance_token();
3667 source_location expr_location = this->location();
3668 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
3669 Call_expression* call_expr = expr->call_expression();
3670 if (call_expr == NULL)
3672 error_at(expr_location, "expected call expression");
3676 // Make it easier to simplify go/defer statements by putting every
3677 // statement in its own block.
3678 this->gogo_->start_block(stat_location);
3681 stat = Statement::make_go_statement(call_expr, stat_location);
3683 stat = Statement::make_defer_statement(call_expr, stat_location);
3684 this->gogo_->add_statement(stat);
3685 this->gogo_->add_block(this->gogo_->finish_block(stat_location),
3689 // ReturnStat = "return" [ ExpressionList ] .
3692 Parse::return_stat()
3694 gcc_assert(this->peek_token()->is_keyword(KEYWORD_RETURN));
3695 source_location location = this->location();
3696 this->advance_token();
3697 Expression_list* vals = NULL;
3698 if (this->expression_may_start_here())
3699 vals = this->expression_list(NULL, false);
3700 const Function* function = this->gogo_->current_function()->func_value();
3701 const Typed_identifier_list* results = function->type()->results();
3702 this->gogo_->add_statement(Statement::make_return_statement(results, vals,
3706 // IfStmt = "if" [ SimpleStmt ";" ] Expression Block [ "else" Statement ] .
3711 gcc_assert(this->peek_token()->is_keyword(KEYWORD_IF));
3712 source_location location = this->location();
3713 this->advance_token();
3715 this->gogo_->start_block(location);
3717 Expression* cond = NULL;
3718 if (this->simple_stat_may_start_here())
3719 cond = this->simple_stat(false, true, NULL, NULL);
3720 if (cond != NULL && this->peek_token()->is_op(OPERATOR_SEMICOLON))
3722 // The SimpleStat is an expression statement.
3723 this->expression_stat(cond);
3728 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3729 this->advance_token();
3730 cond = this->expression(PRECEDENCE_NORMAL, false, false, NULL);
3733 this->gogo_->start_block(this->location());
3734 source_location end_loc = this->block();
3735 Block* then_block = this->gogo_->finish_block(end_loc);
3737 // Check for the easy error of a newline before "else".
3738 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3740 source_location semi_loc = this->location();
3741 if (this->advance_token()->is_keyword(KEYWORD_ELSE))
3742 error_at(this->location(),
3743 "unexpected semicolon or newline before %<else%>");
3745 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
3749 Block* else_block = NULL;
3750 if (this->peek_token()->is_keyword(KEYWORD_ELSE))
3752 this->advance_token();
3753 // We create a block to gather the statement.
3754 this->gogo_->start_block(this->location());
3755 this->statement(NULL);
3756 else_block = this->gogo_->finish_block(this->location());
3759 this->gogo_->add_statement(Statement::make_if_statement(cond, then_block,
3763 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3767 // SwitchStmt = ExprSwitchStmt | TypeSwitchStmt .
3768 // ExprSwitchStmt = "switch" [ [ SimpleStat ] ";" ] [ Expression ]
3769 // "{" { ExprCaseClause } "}" .
3770 // TypeSwitchStmt = "switch" [ [ SimpleStat ] ";" ] TypeSwitchGuard
3771 // "{" { TypeCaseClause } "}" .
3772 // TypeSwitchGuard = [ identifier ":=" ] Expression "." "(" "type" ")" .
3775 Parse::switch_stat(const Label* label)
3777 gcc_assert(this->peek_token()->is_keyword(KEYWORD_SWITCH));
3778 source_location location = this->location();
3779 this->advance_token();
3781 this->gogo_->start_block(location);
3783 Expression* switch_val = NULL;
3784 Type_switch type_switch;
3785 if (this->simple_stat_may_start_here())
3786 switch_val = this->simple_stat(false, true, NULL, &type_switch);
3787 if (switch_val != NULL && this->peek_token()->is_op(OPERATOR_SEMICOLON))
3789 // The SimpleStat is an expression statement.
3790 this->expression_stat(switch_val);
3793 if (switch_val == NULL && !type_switch.found)
3795 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3796 this->advance_token();
3797 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3799 if (this->peek_token()->is_identifier())
3801 const Token* token = this->peek_token();
3802 std::string identifier = token->identifier();
3803 bool is_exported = token->is_identifier_exported();
3804 source_location id_loc = token->location();
3806 token = this->advance_token();
3807 bool is_coloneq = token->is_op(OPERATOR_COLONEQ);
3808 this->unget_token(Token::make_identifier_token(identifier,
3813 // This must be a TypeSwitchGuard.
3814 switch_val = this->simple_stat(false, true, NULL,
3816 if (!type_switch.found)
3818 if (switch_val == NULL
3819 || !switch_val->is_error_expression())
3821 error_at(id_loc, "expected type switch assignment");
3822 switch_val = Expression::make_error(id_loc);
3827 if (switch_val == NULL && !type_switch.found)
3829 switch_val = this->expression(PRECEDENCE_NORMAL, false, false,
3830 &type_switch.found);
3831 if (type_switch.found)
3833 type_switch.name.clear();
3834 type_switch.expr = switch_val;
3835 type_switch.location = switch_val->location();
3841 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3843 source_location token_loc = this->location();
3844 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
3845 && this->advance_token()->is_op(OPERATOR_LCURLY))
3846 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
3849 error_at(this->location(), "expected %<{%>");
3850 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3855 this->advance_token();
3857 Statement* statement;
3858 if (type_switch.found)
3859 statement = this->type_switch_body(label, type_switch, location);
3861 statement = this->expr_switch_body(label, switch_val, location);
3863 if (statement != NULL)
3864 this->gogo_->add_statement(statement);
3866 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3870 // The body of an expression switch.
3871 // "{" { ExprCaseClause } "}"
3874 Parse::expr_switch_body(const Label* label, Expression* switch_val,
3875 source_location location)
3877 Switch_statement* statement = Statement::make_switch_statement(switch_val,
3880 this->push_break_statement(statement, label);
3882 Case_clauses* case_clauses = new Case_clauses();
3883 bool saw_default = false;
3884 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
3886 if (this->peek_token()->is_eof())
3889 error_at(this->location(), "missing %<}%>");
3892 this->expr_case_clause(case_clauses, &saw_default);
3894 this->advance_token();
3896 statement->add_clauses(case_clauses);
3898 this->pop_break_statement();
3903 // ExprCaseClause = ExprSwitchCase ":" [ StatementList ] .
3904 // FallthroughStat = "fallthrough" .
3907 Parse::expr_case_clause(Case_clauses* clauses, bool* saw_default)
3909 source_location location = this->location();
3911 bool is_default = false;
3912 Expression_list* vals = this->expr_switch_case(&is_default);
3914 if (!this->peek_token()->is_op(OPERATOR_COLON))
3917 error_at(this->location(), "expected %<:%>");
3921 this->advance_token();
3923 Block* statements = NULL;
3924 if (this->statement_list_may_start_here())
3926 this->gogo_->start_block(this->location());
3927 this->statement_list();
3928 statements = this->gogo_->finish_block(this->location());
3931 bool is_fallthrough = false;
3932 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH))
3934 is_fallthrough = true;
3935 if (this->advance_token()->is_op(OPERATOR_SEMICOLON))
3936 this->advance_token();
3943 error_at(location, "multiple defaults in switch");
3946 *saw_default = true;
3949 if (is_default || vals != NULL)
3950 clauses->add(vals, is_default, statements, is_fallthrough, location);
3953 // ExprSwitchCase = "case" ExpressionList | "default" .
3956 Parse::expr_switch_case(bool* is_default)
3958 const Token* token = this->peek_token();
3959 if (token->is_keyword(KEYWORD_CASE))
3961 this->advance_token();
3962 return this->expression_list(NULL, false);
3964 else if (token->is_keyword(KEYWORD_DEFAULT))
3966 this->advance_token();
3973 error_at(this->location(), "expected %<case%> or %<default%>");
3974 if (!token->is_op(OPERATOR_RCURLY))
3975 this->advance_token();
3980 // The body of a type switch.
3981 // "{" { TypeCaseClause } "}" .
3984 Parse::type_switch_body(const Label* label, const Type_switch& type_switch,
3985 source_location location)
3987 Named_object* switch_no = NULL;
3988 if (!type_switch.name.empty())
3990 Variable* switch_var = new Variable(NULL, type_switch.expr, false, false,
3991 false, type_switch.location);
3992 switch_no = this->gogo_->add_variable(type_switch.name, switch_var);
3995 Type_switch_statement* statement =
3996 Statement::make_type_switch_statement(switch_no,
4002 this->push_break_statement(statement, label);
4004 Type_case_clauses* case_clauses = new Type_case_clauses();
4005 bool saw_default = false;
4006 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
4008 if (this->peek_token()->is_eof())
4010 error_at(this->location(), "missing %<}%>");
4013 this->type_case_clause(switch_no, case_clauses, &saw_default);
4015 this->advance_token();
4017 statement->add_clauses(case_clauses);
4019 this->pop_break_statement();
4024 // TypeCaseClause = TypeSwitchCase ":" [ StatementList ] .
4027 Parse::type_case_clause(Named_object* switch_no, Type_case_clauses* clauses,
4030 source_location location = this->location();
4032 std::vector<Type*> types;
4033 bool is_default = false;
4034 this->type_switch_case(&types, &is_default);
4036 if (!this->peek_token()->is_op(OPERATOR_COLON))
4037 error_at(this->location(), "expected %<:%>");
4039 this->advance_token();
4041 Block* statements = NULL;
4042 if (this->statement_list_may_start_here())
4044 this->gogo_->start_block(this->location());
4045 if (switch_no != NULL && types.size() == 1)
4047 Type* type = types.front();
4048 Expression* init = Expression::make_var_reference(switch_no,
4050 init = Expression::make_type_guard(init, type, location);
4051 Variable* v = new Variable(type, init, false, false, false,
4053 v->set_is_type_switch_var();
4054 this->gogo_->add_variable(switch_no->name(), v);
4056 this->statement_list();
4057 statements = this->gogo_->finish_block(this->location());
4060 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH))
4062 error_at(this->location(),
4063 "fallthrough is not permitted in a type switch");
4064 if (this->advance_token()->is_op(OPERATOR_SEMICOLON))
4065 this->advance_token();
4070 gcc_assert(types.empty());
4073 error_at(location, "multiple defaults in type switch");
4076 *saw_default = true;
4077 clauses->add(NULL, false, true, statements, location);
4079 else if (!types.empty())
4081 for (std::vector<Type*>::const_iterator p = types.begin();
4082 p + 1 != types.end();
4084 clauses->add(*p, true, false, NULL, location);
4085 clauses->add(types.back(), false, false, statements, location);
4088 clauses->add(Type::make_error_type(), false, false, statements, location);
4091 // TypeSwitchCase = "case" type | "default"
4093 // We accept a comma separated list of types.
4096 Parse::type_switch_case(std::vector<Type*>* types, bool* is_default)
4098 const Token* token = this->peek_token();
4099 if (token->is_keyword(KEYWORD_CASE))
4101 this->advance_token();
4104 Type* t = this->type();
4105 if (!t->is_error_type())
4106 types->push_back(t);
4107 if (!this->peek_token()->is_op(OPERATOR_COMMA))
4109 this->advance_token();
4112 else if (token->is_keyword(KEYWORD_DEFAULT))
4114 this->advance_token();
4119 error_at(this->location(), "expected %<case%> or %<default%>");
4120 if (!token->is_op(OPERATOR_RCURLY))
4121 this->advance_token();
4125 // SelectStat = "select" "{" { CommClause } "}" .
4128 Parse::select_stat(const Label* label)
4130 gcc_assert(this->peek_token()->is_keyword(KEYWORD_SELECT));
4131 source_location location = this->location();
4132 const Token* token = this->advance_token();
4134 if (!token->is_op(OPERATOR_LCURLY))
4136 source_location token_loc = token->location();
4137 if (token->is_op(OPERATOR_SEMICOLON)
4138 && this->advance_token()->is_op(OPERATOR_LCURLY))
4139 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
4142 error_at(this->location(), "expected %<{%>");
4146 this->advance_token();
4148 Select_statement* statement = Statement::make_select_statement(location);
4150 this->push_break_statement(statement, label);
4152 Select_clauses* select_clauses = new Select_clauses();
4153 bool saw_default = false;
4154 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
4156 if (this->peek_token()->is_eof())
4158 error_at(this->location(), "expected %<}%>");
4161 this->comm_clause(select_clauses, &saw_default);
4164 this->advance_token();
4166 statement->add_clauses(select_clauses);
4168 this->pop_break_statement();
4170 this->gogo_->add_statement(statement);
4173 // CommClause = CommCase ":" { Statement ";" } .
4176 Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
4178 source_location location = this->location();
4179 bool is_send = false;
4180 Expression* channel = NULL;
4181 Expression* val = NULL;
4182 std::string varname;
4183 bool is_default = false;
4184 bool got_case = this->comm_case(&is_send, &channel, &val, &varname,
4187 if (this->peek_token()->is_op(OPERATOR_COLON))
4188 this->advance_token();
4190 error_at(this->location(), "expected colon");
4192 Block* statements = NULL;
4193 Named_object* var = NULL;
4194 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
4195 this->advance_token();
4196 else if (this->statement_list_may_start_here())
4198 this->gogo_->start_block(this->location());
4200 if (!varname.empty())
4202 // FIXME: LOCATION is slightly wrong here.
4203 Variable* v = new Variable(NULL, channel, false, false, false,
4205 v->set_type_from_chan_element();
4206 var = this->gogo_->add_variable(varname, v);
4209 this->statement_list();
4210 statements = this->gogo_->finish_block(this->location());
4217 error_at(location, "multiple defaults in select");
4220 *saw_default = true;
4224 clauses->add(is_send, channel, val, var, is_default, statements, location);
4225 else if (statements != NULL)
4227 // Add the statements to make sure that any names they define
4229 this->gogo_->add_block(statements, location);
4233 // CommCase = "case" ( SendStmt | RecvStmt ) | "default" .
4236 Parse::comm_case(bool* is_send, Expression** channel, Expression** val,
4237 std::string* varname, bool* is_default)
4239 const Token* token = this->peek_token();
4240 if (token->is_keyword(KEYWORD_DEFAULT))
4242 this->advance_token();
4245 else if (token->is_keyword(KEYWORD_CASE))
4247 this->advance_token();
4248 if (!this->send_or_recv_expr(is_send, channel, val, varname))
4253 error_at(this->location(), "expected %<case%> or %<default%>");
4254 if (!token->is_op(OPERATOR_RCURLY))
4255 this->advance_token();
4262 // RecvExpr = [ Expression ( "=" | ":=" ) ] "<-" Expression .
4265 Parse::send_or_recv_expr(bool* is_send, Expression** channel, Expression** val,
4266 std::string* varname)
4268 const Token* token = this->peek_token();
4269 source_location location = token->location();
4270 if (token->is_identifier())
4272 std::string recv_var = token->identifier();
4273 bool is_var_exported = token->is_identifier_exported();
4274 if (!this->advance_token()->is_op(OPERATOR_COLONEQ))
4275 this->unget_token(Token::make_identifier_token(recv_var,
4280 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4282 error_at(this->location(), "expected %<<-%>");
4286 *varname = this->gogo_->pack_hidden_name(recv_var, is_var_exported);
4287 this->advance_token();
4288 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4293 if (this->peek_token()->is_op(OPERATOR_CHANOP))
4296 this->advance_token();
4297 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4301 Expression* left = this->expression(PRECEDENCE_NORMAL, true, true, NULL);
4303 if (this->peek_token()->is_op(OPERATOR_EQ))
4305 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4307 error_at(this->location(), "missing %<<-%>");
4312 this->advance_token();
4313 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4315 else if (this->peek_token()->is_op(OPERATOR_CHANOP))
4318 *channel = this->verify_not_sink(left);
4319 this->advance_token();
4320 *val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4324 error_at(this->location(), "expected %<<-%> or %<=%>");
4332 // ForStat = "for" [ Condition | ForClause | RangeClause ] Block .
4333 // Condition = Expression .
4336 Parse::for_stat(const Label* label)
4338 gcc_assert(this->peek_token()->is_keyword(KEYWORD_FOR));
4339 source_location location = this->location();
4340 const Token* token = this->advance_token();
4342 // Open a block to hold any variables defined in the init statement
4343 // of the for statement.
4344 this->gogo_->start_block(location);
4347 Expression* cond = NULL;
4349 Range_clause range_clause;
4351 if (!token->is_op(OPERATOR_LCURLY))
4353 if (token->is_keyword(KEYWORD_VAR))
4355 error_at(this->location(),
4356 "var declaration not allowed in for initializer");
4360 if (token->is_op(OPERATOR_SEMICOLON))
4361 this->for_clause(&cond, &post);
4364 // We might be looking at a Condition, an InitStat, or a
4366 cond = this->simple_stat(false, true, &range_clause, NULL);
4367 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
4369 if (cond == NULL && !range_clause.found)
4370 error_at(this->location(), "parse error in for statement");
4374 if (range_clause.found)
4375 error_at(this->location(), "parse error after range clause");
4379 // COND is actually an expression statement for
4380 // InitStat at the start of a ForClause.
4381 this->expression_stat(cond);
4385 this->for_clause(&cond, &post);
4390 // Build the For_statement and note that it is the current target
4391 // for break and continue statements.
4393 For_statement* sfor;
4394 For_range_statement* srange;
4396 if (!range_clause.found)
4398 sfor = Statement::make_for_statement(init, cond, post, location);
4404 srange = Statement::make_for_range_statement(range_clause.index,
4412 this->push_break_statement(s, label);
4413 this->push_continue_statement(s, label);
4415 // Gather the block of statements in the loop and add them to the
4418 this->gogo_->start_block(this->location());
4419 source_location end_loc = this->block();
4420 Block* statements = this->gogo_->finish_block(end_loc);
4423 sfor->add_statements(statements);
4425 srange->add_statements(statements);
4427 // This is no longer the break/continue target.
4428 this->pop_break_statement();
4429 this->pop_continue_statement();
4431 // Add the For_statement to the list of statements, and close out
4432 // the block we started to hold any variables defined in the for
4435 this->gogo_->add_statement(s);
4437 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
4441 // ForClause = [ InitStat ] ";" [ Condition ] ";" [ PostStat ] .
4442 // InitStat = SimpleStat .
4443 // PostStat = SimpleStat .
4445 // We have already read InitStat at this point.
4448 Parse::for_clause(Expression** cond, Block** post)
4450 gcc_assert(this->peek_token()->is_op(OPERATOR_SEMICOLON));
4451 this->advance_token();
4452 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
4454 else if (this->peek_token()->is_op(OPERATOR_LCURLY))
4456 error_at(this->location(),
4457 "unexpected semicolon or newline before %<{%>");
4463 *cond = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4464 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
4465 error_at(this->location(), "expected semicolon");
4467 this->advance_token();
4469 if (this->peek_token()->is_op(OPERATOR_LCURLY))
4473 this->gogo_->start_block(this->location());
4474 this->simple_stat(false, false, NULL, NULL);
4475 *post = this->gogo_->finish_block(this->location());
4479 // RangeClause = IdentifierList ( "=" | ":=" ) "range" Expression .
4481 // This is the := version. It is called with a list of identifiers.
4484 Parse::range_clause_decl(const Typed_identifier_list* til,
4485 Range_clause* p_range_clause)
4487 gcc_assert(this->peek_token()->is_keyword(KEYWORD_RANGE));
4488 source_location location = this->location();
4490 p_range_clause->found = true;
4492 gcc_assert(til->size() >= 1);
4493 if (til->size() > 2)
4494 error_at(this->location(), "too many variables for range clause");
4496 this->advance_token();
4497 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, false, NULL);
4498 p_range_clause->range = expr;
4500 bool any_new = false;
4502 const Typed_identifier* pti = &til->front();
4503 Named_object* no = this->init_var(*pti, NULL, expr, true, true, &any_new);
4504 if (any_new && no->is_variable())
4505 no->var_value()->set_type_from_range_index();
4506 p_range_clause->index = Expression::make_var_reference(no, location);
4508 if (til->size() == 1)
4509 p_range_clause->value = NULL;
4513 bool is_new = false;
4514 no = this->init_var(*pti, NULL, expr, true, true, &is_new);
4515 if (is_new && no->is_variable())
4516 no->var_value()->set_type_from_range_value();
4519 p_range_clause->value = Expression::make_var_reference(no, location);
4523 error_at(location, "variables redeclared but no variable is new");
4526 // The = version of RangeClause. This is called with a list of
4530 Parse::range_clause_expr(const Expression_list* vals,
4531 Range_clause* p_range_clause)
4533 gcc_assert(this->peek_token()->is_keyword(KEYWORD_RANGE));
4535 p_range_clause->found = true;
4537 gcc_assert(vals->size() >= 1);
4538 if (vals->size() > 2)
4539 error_at(this->location(), "too many variables for range clause");
4541 this->advance_token();
4542 p_range_clause->range = this->expression(PRECEDENCE_NORMAL, false, false,
4545 p_range_clause->index = vals->front();
4546 if (vals->size() == 1)
4547 p_range_clause->value = NULL;
4549 p_range_clause->value = vals->back();
4552 // Push a statement on the break stack.
4555 Parse::push_break_statement(Statement* enclosing, const Label* label)
4557 if (this->break_stack_ == NULL)
4558 this->break_stack_ = new Bc_stack();
4559 this->break_stack_->push_back(std::make_pair(enclosing, label));
4562 // Push a statement on the continue stack.
4565 Parse::push_continue_statement(Statement* enclosing, const Label* label)
4567 if (this->continue_stack_ == NULL)
4568 this->continue_stack_ = new Bc_stack();
4569 this->continue_stack_->push_back(std::make_pair(enclosing, label));
4572 // Pop the break stack.
4575 Parse::pop_break_statement()
4577 this->break_stack_->pop_back();
4580 // Pop the continue stack.
4583 Parse::pop_continue_statement()
4585 this->continue_stack_->pop_back();
4588 // Find a break or continue statement given a label name.
4591 Parse::find_bc_statement(const Bc_stack* bc_stack, const std::string& label)
4593 if (bc_stack == NULL)
4595 for (Bc_stack::const_reverse_iterator p = bc_stack->rbegin();
4596 p != bc_stack->rend();
4598 if (p->second != NULL && p->second->name() == label)
4603 // BreakStat = "break" [ identifier ] .
4608 gcc_assert(this->peek_token()->is_keyword(KEYWORD_BREAK));
4609 source_location location = this->location();
4611 const Token* token = this->advance_token();
4612 Statement* enclosing;
4613 if (!token->is_identifier())
4615 if (this->break_stack_ == NULL || this->break_stack_->empty())
4617 error_at(this->location(),
4618 "break statement not within for or switch or select");
4621 enclosing = this->break_stack_->back().first;
4625 enclosing = this->find_bc_statement(this->break_stack_,
4626 token->identifier());
4627 if (enclosing == NULL)
4629 error_at(token->location(),
4630 ("break label %qs not associated with "
4631 "for or switch or select"),
4632 Gogo::message_name(token->identifier()).c_str());
4633 this->advance_token();
4636 this->advance_token();
4639 Unnamed_label* label;
4640 if (enclosing->classification() == Statement::STATEMENT_FOR)
4641 label = enclosing->for_statement()->break_label();
4642 else if (enclosing->classification() == Statement::STATEMENT_FOR_RANGE)
4643 label = enclosing->for_range_statement()->break_label();
4644 else if (enclosing->classification() == Statement::STATEMENT_SWITCH)
4645 label = enclosing->switch_statement()->break_label();
4646 else if (enclosing->classification() == Statement::STATEMENT_TYPE_SWITCH)
4647 label = enclosing->type_switch_statement()->break_label();
4648 else if (enclosing->classification() == Statement::STATEMENT_SELECT)
4649 label = enclosing->select_statement()->break_label();
4653 this->gogo_->add_statement(Statement::make_break_statement(label,
4657 // ContinueStat = "continue" [ identifier ] .
4660 Parse::continue_stat()
4662 gcc_assert(this->peek_token()->is_keyword(KEYWORD_CONTINUE));
4663 source_location location = this->location();
4665 const Token* token = this->advance_token();
4666 Statement* enclosing;
4667 if (!token->is_identifier())
4669 if (this->continue_stack_ == NULL || this->continue_stack_->empty())
4671 error_at(this->location(), "continue statement not within for");
4674 enclosing = this->continue_stack_->back().first;
4678 enclosing = this->find_bc_statement(this->continue_stack_,
4679 token->identifier());
4680 if (enclosing == NULL)
4682 error_at(token->location(),
4683 "continue label %qs not associated with for",
4684 Gogo::message_name(token->identifier()).c_str());
4685 this->advance_token();
4688 this->advance_token();
4691 Unnamed_label* label;
4692 if (enclosing->classification() == Statement::STATEMENT_FOR)
4693 label = enclosing->for_statement()->continue_label();
4694 else if (enclosing->classification() == Statement::STATEMENT_FOR_RANGE)
4695 label = enclosing->for_range_statement()->continue_label();
4699 this->gogo_->add_statement(Statement::make_continue_statement(label,
4703 // GotoStat = "goto" identifier .
4708 gcc_assert(this->peek_token()->is_keyword(KEYWORD_GOTO));
4709 source_location location = this->location();
4710 const Token* token = this->advance_token();
4711 if (!token->is_identifier())
4712 error_at(this->location(), "expected label for goto");
4715 Label* label = this->gogo_->add_label_reference(token->identifier());
4716 Statement* s = Statement::make_goto_statement(label, location);
4717 this->gogo_->add_statement(s);
4718 this->advance_token();
4722 // PackageClause = "package" PackageName .
4725 Parse::package_clause()
4727 const Token* token = this->peek_token();
4728 source_location location = token->location();
4730 if (!token->is_keyword(KEYWORD_PACKAGE))
4732 error_at(this->location(), "program must start with package clause");
4737 token = this->advance_token();
4738 if (token->is_identifier())
4740 name = token->identifier();
4743 error_at(this->location(), "invalid package name _");
4746 this->advance_token();
4750 error_at(this->location(), "package name must be an identifier");
4754 this->gogo_->set_package_name(name, location);
4757 // ImportDecl = "import" Decl<ImportSpec> .
4760 Parse::import_decl()
4762 gcc_assert(this->peek_token()->is_keyword(KEYWORD_IMPORT));
4763 this->advance_token();
4764 this->decl(&Parse::import_spec, NULL);
4767 // ImportSpec = [ "." | PackageName ] PackageFileName .
4770 Parse::import_spec(void*)
4772 const Token* token = this->peek_token();
4773 source_location location = token->location();
4775 std::string local_name;
4776 bool is_local_name_exported = false;
4777 if (token->is_op(OPERATOR_DOT))
4780 token = this->advance_token();
4782 else if (token->is_identifier())
4784 local_name = token->identifier();
4785 is_local_name_exported = token->is_identifier_exported();
4786 token = this->advance_token();
4789 if (!token->is_string())
4791 error_at(this->location(), "missing import package name");
4795 this->gogo_->import_package(token->string_value(), local_name,
4796 is_local_name_exported, location);
4798 this->advance_token();
4801 // SourceFile = PackageClause ";" { ImportDecl ";" }
4802 // { TopLevelDecl ";" } .
4807 this->package_clause();
4809 const Token* token = this->peek_token();
4810 if (token->is_op(OPERATOR_SEMICOLON))
4811 token = this->advance_token();
4813 error_at(this->location(),
4814 "expected %<;%> or newline after package clause");
4816 while (token->is_keyword(KEYWORD_IMPORT))
4818 this->import_decl();
4819 token = this->peek_token();
4820 if (token->is_op(OPERATOR_SEMICOLON))
4821 token = this->advance_token();
4823 error_at(this->location(),
4824 "expected %<;%> or newline after import declaration");
4827 while (!token->is_eof())
4829 if (this->declaration_may_start_here())
4830 this->declaration();
4833 error_at(this->location(), "expected declaration");
4835 this->advance_token();
4836 while (!this->peek_token()->is_eof()
4837 && !this->peek_token()->is_op(OPERATOR_SEMICOLON)
4838 && !this->peek_token()->is_op(OPERATOR_RCURLY));
4839 if (!this->peek_token()->is_eof()
4840 && !this->peek_token()->is_op(OPERATOR_SEMICOLON))
4841 this->advance_token();
4843 token = this->peek_token();
4844 if (token->is_op(OPERATOR_SEMICOLON))
4845 token = this->advance_token();
4846 else if (!token->is_eof() || !saw_errors())
4848 error_at(this->location(),
4849 "expected %<;%> or newline after top level declaration");
4850 this->skip_past_error(OPERATOR_INVALID);
4855 // Reset the current iota value.
4863 // Return the current iota value.
4871 // Increment the current iota value.
4874 Parse::increment_iota()
4879 // Skip forward to a semicolon or OP. OP will normally be
4880 // OPERATOR_RPAREN or OPERATOR_RCURLY. If we find a semicolon, move
4881 // past it and return. If we find OP, it will be the next token to
4882 // read. Return true if we are OK, false if we found EOF.
4885 Parse::skip_past_error(Operator op)
4887 const Token* token = this->peek_token();
4888 while (!token->is_op(op))
4890 if (token->is_eof())
4892 if (token->is_op(OPERATOR_SEMICOLON))
4894 this->advance_token();
4897 token = this->advance_token();
4902 // Check that an expression is not a sink.
4905 Parse::verify_not_sink(Expression* expr)
4907 if (expr->is_sink_expression())
4909 error_at(expr->location(), "cannot use _ as value");
4910 expr = Expression::make_error(expr->location());