1 // parse.cc -- Go frontend parser.
3 // Copyright 2009 The Go Authors. All rights reserved.
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file.
12 #include "statements.h"
13 #include "expressions.h"
16 // Struct Parse::Enclosing_var_comparison.
18 // Return true if v1 should be considered to be less than v2.
21 Parse::Enclosing_var_comparison::operator()(const Enclosing_var& v1,
22 const Enclosing_var& v2)
24 if (v1.var() == v2.var())
27 const std::string& n1(v1.var()->name());
28 const std::string& n2(v2.var()->name());
29 int i = n1.compare(n2);
35 // If we get here it means that a single nested function refers to
36 // two different variables defined in enclosing functions, and both
37 // variables have the same name. I think this is impossible.
43 Parse::Parse(Lex* lex, Gogo* gogo)
45 token_(Token::make_invalid_token(0)),
46 unget_token_(Token::make_invalid_token(0)),
47 unget_token_valid_(false),
50 continue_stack_(NULL),
56 // Return the current token.
61 if (this->unget_token_valid_)
62 return &this->unget_token_;
63 if (this->token_.is_invalid())
64 this->token_ = this->lex_->next_token();
68 // Advance to the next token and return it.
71 Parse::advance_token()
73 if (this->unget_token_valid_)
75 this->unget_token_valid_ = false;
76 if (!this->token_.is_invalid())
79 this->token_ = this->lex_->next_token();
83 // Push a token back on the input stream.
86 Parse::unget_token(const Token& token)
88 go_assert(!this->unget_token_valid_);
89 this->unget_token_ = token;
90 this->unget_token_valid_ = true;
93 // The location of the current token.
98 return this->peek_token()->location();
101 // IdentifierList = identifier { "," identifier } .
104 Parse::identifier_list(Typed_identifier_list* til)
106 const Token* token = this->peek_token();
109 if (!token->is_identifier())
111 error_at(this->location(), "expected identifier");
115 this->gogo_->pack_hidden_name(token->identifier(),
116 token->is_identifier_exported());
117 til->push_back(Typed_identifier(name, NULL, token->location()));
118 token = this->advance_token();
119 if (!token->is_op(OPERATOR_COMMA))
121 token = this->advance_token();
125 // ExpressionList = Expression { "," Expression } .
127 // If MAY_BE_SINK is true, the expressions in the list may be "_".
130 Parse::expression_list(Expression* first, bool may_be_sink)
132 Expression_list* ret = new Expression_list();
134 ret->push_back(first);
137 ret->push_back(this->expression(PRECEDENCE_NORMAL, may_be_sink, true,
140 const Token* token = this->peek_token();
141 if (!token->is_op(OPERATOR_COMMA))
144 // Most expression lists permit a trailing comma.
145 source_location location = token->location();
146 this->advance_token();
147 if (!this->expression_may_start_here())
149 this->unget_token(Token::make_operator_token(OPERATOR_COMMA,
156 // QualifiedIdent = [ PackageName "." ] identifier .
157 // PackageName = identifier .
159 // This sets *PNAME to the identifier and sets *PPACKAGE to the
160 // package or NULL if there isn't one. This returns true on success,
161 // false on failure in which case it will have emitted an error
165 Parse::qualified_ident(std::string* pname, Named_object** ppackage)
167 const Token* token = this->peek_token();
168 if (!token->is_identifier())
170 error_at(this->location(), "expected identifier");
174 std::string name = token->identifier();
175 bool is_exported = token->is_identifier_exported();
176 name = this->gogo_->pack_hidden_name(name, is_exported);
178 token = this->advance_token();
179 if (!token->is_op(OPERATOR_DOT))
186 Named_object* package = this->gogo_->lookup(name, NULL);
187 if (package == NULL || !package->is_package())
189 error_at(this->location(), "expected package");
190 // We expect . IDENTIFIER; skip both.
191 if (this->advance_token()->is_identifier())
192 this->advance_token();
196 package->package_value()->set_used();
198 token = this->advance_token();
199 if (!token->is_identifier())
201 error_at(this->location(), "expected identifier");
205 name = token->identifier();
209 error_at(this->location(), "invalid use of %<_%>");
213 if (package->name() == this->gogo_->package_name())
214 name = this->gogo_->pack_hidden_name(name,
215 token->is_identifier_exported());
220 this->advance_token();
225 // Type = TypeName | TypeLit | "(" Type ")" .
227 // ArrayType | StructType | PointerType | FunctionType | InterfaceType |
228 // SliceType | MapType | ChannelType .
233 const Token* token = this->peek_token();
234 if (token->is_identifier())
235 return this->type_name(true);
236 else if (token->is_op(OPERATOR_LSQUARE))
237 return this->array_type(false);
238 else if (token->is_keyword(KEYWORD_CHAN)
239 || token->is_op(OPERATOR_CHANOP))
240 return this->channel_type();
241 else if (token->is_keyword(KEYWORD_INTERFACE))
242 return this->interface_type();
243 else if (token->is_keyword(KEYWORD_FUNC))
245 source_location location = token->location();
246 this->advance_token();
247 Type* type = this->signature(NULL, location);
249 return Type::make_error_type();
252 else if (token->is_keyword(KEYWORD_MAP))
253 return this->map_type();
254 else if (token->is_keyword(KEYWORD_STRUCT))
255 return this->struct_type();
256 else if (token->is_op(OPERATOR_MULT))
257 return this->pointer_type();
258 else if (token->is_op(OPERATOR_LPAREN))
260 this->advance_token();
261 Type* ret = this->type();
262 if (this->peek_token()->is_op(OPERATOR_RPAREN))
263 this->advance_token();
266 if (!ret->is_error_type())
267 error_at(this->location(), "expected %<)%>");
273 error_at(token->location(), "expected type");
274 return Type::make_error_type();
279 Parse::type_may_start_here()
281 const Token* token = this->peek_token();
282 return (token->is_identifier()
283 || token->is_op(OPERATOR_LSQUARE)
284 || token->is_op(OPERATOR_CHANOP)
285 || token->is_keyword(KEYWORD_CHAN)
286 || token->is_keyword(KEYWORD_INTERFACE)
287 || token->is_keyword(KEYWORD_FUNC)
288 || token->is_keyword(KEYWORD_MAP)
289 || token->is_keyword(KEYWORD_STRUCT)
290 || token->is_op(OPERATOR_MULT)
291 || token->is_op(OPERATOR_LPAREN));
294 // TypeName = QualifiedIdent .
296 // If MAY_BE_NIL is true, then an identifier with the value of the
297 // predefined constant nil is accepted, returning the nil type.
300 Parse::type_name(bool issue_error)
302 source_location location = this->location();
305 Named_object* package;
306 if (!this->qualified_ident(&name, &package))
307 return Type::make_error_type();
309 Named_object* named_object;
311 named_object = this->gogo_->lookup(name, NULL);
314 named_object = package->package_value()->lookup(name);
315 if (named_object == NULL
317 && package->name() != this->gogo_->package_name())
319 // Check whether the name is there but hidden.
320 std::string s = ('.' + package->package_value()->unique_prefix()
321 + '.' + package->package_value()->name()
323 named_object = package->package_value()->lookup(s);
324 if (named_object != NULL)
326 const std::string& packname(package->package_value()->name());
327 error_at(location, "invalid reference to hidden type %<%s.%s%>",
328 Gogo::message_name(packname).c_str(),
329 Gogo::message_name(name).c_str());
336 if (named_object == NULL)
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 go_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 go_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 go_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 go_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 go_assert(token->is_keyword(KEYWORD_CHAN));
653 if (this->advance_token()->is_op(OPERATOR_CHANOP))
656 this->advance_token();
660 // Better error messages for the common error of omitting the
661 // channel element type.
662 if (!this->type_may_start_here())
664 token = this->peek_token();
665 if (token->is_op(OPERATOR_RCURLY))
666 error_at(this->location(), "unexpected %<}%> in channel type");
667 else if (token->is_op(OPERATOR_RPAREN))
668 error_at(this->location(), "unexpected %<)%> in channel type");
669 else if (token->is_op(OPERATOR_COMMA))
670 error_at(this->location(), "unexpected comma in channel type");
672 error_at(this->location(), "expected channel element type");
673 return Type::make_error_type();
676 Type* element_type = this->type();
677 return Type::make_channel_type(send, receive, element_type);
680 // Signature = Parameters [ Result ] .
682 // RECEIVER is the receiver if there is one, or NULL. LOCATION is the
683 // location of the start of the type.
685 // This returns NULL on a parse error.
688 Parse::signature(Typed_identifier* receiver, source_location location)
690 bool is_varargs = false;
691 Typed_identifier_list* params;
692 bool params_ok = this->parameters(¶ms, &is_varargs);
694 Typed_identifier_list* result = NULL;
695 if (this->peek_token()->is_op(OPERATOR_LPAREN)
696 || this->type_may_start_here())
698 if (!this->result(&result))
705 Function_type* ret = Type::make_function_type(receiver, params, result,
708 ret->set_is_varargs();
712 // Parameters = "(" [ ParameterList [ "," ] ] ")" .
714 // This returns false on a parse error.
717 Parse::parameters(Typed_identifier_list** pparams, bool* is_varargs)
721 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
723 error_at(this->location(), "expected %<(%>");
727 Typed_identifier_list* params = NULL;
728 bool saw_error = false;
730 const Token* token = this->advance_token();
731 if (!token->is_op(OPERATOR_RPAREN))
733 params = this->parameter_list(is_varargs);
736 token = this->peek_token();
739 // The optional trailing comma is picked up in parameter_list.
741 if (!token->is_op(OPERATOR_RPAREN))
742 error_at(this->location(), "expected %<)%>");
744 this->advance_token();
753 // ParameterList = ParameterDecl { "," ParameterDecl } .
755 // This sets *IS_VARARGS if the list ends with an ellipsis.
756 // IS_VARARGS will be NULL if varargs are not permitted.
758 // We pick up an optional trailing comma.
760 // This returns NULL if some error is seen.
762 Typed_identifier_list*
763 Parse::parameter_list(bool* is_varargs)
765 source_location location = this->location();
766 Typed_identifier_list* ret = new Typed_identifier_list();
768 bool saw_error = false;
770 // If we see an identifier and then a comma, then we don't know
771 // whether we are looking at a list of identifiers followed by a
772 // type, or a list of types given by name. We have to do an
773 // arbitrary lookahead to figure it out.
775 bool parameters_have_names;
776 const Token* token = this->peek_token();
777 if (!token->is_identifier())
779 // This must be a type which starts with something like '*'.
780 parameters_have_names = false;
784 std::string name = token->identifier();
785 bool is_exported = token->is_identifier_exported();
786 source_location location = token->location();
787 token = this->advance_token();
788 if (!token->is_op(OPERATOR_COMMA))
790 if (token->is_op(OPERATOR_DOT))
792 // This is a qualified identifier, which must turn out
794 parameters_have_names = false;
796 else if (token->is_op(OPERATOR_RPAREN))
798 // A single identifier followed by a parenthesis must be
800 parameters_have_names = false;
804 // An identifier followed by something other than a
805 // comma or a dot or a right parenthesis must be a
806 // parameter name followed by a type.
807 parameters_have_names = true;
810 this->unget_token(Token::make_identifier_token(name, is_exported,
815 // An identifier followed by a comma may be the first in a
816 // list of parameter names followed by a type, or it may be
817 // the first in a list of types without parameter names. To
818 // find out we gather as many identifiers separated by
820 std::string id_name = this->gogo_->pack_hidden_name(name,
822 ret->push_back(Typed_identifier(id_name, NULL, location));
823 bool just_saw_comma = true;
824 while (this->advance_token()->is_identifier())
826 name = this->peek_token()->identifier();
827 is_exported = this->peek_token()->is_identifier_exported();
828 location = this->peek_token()->location();
829 id_name = this->gogo_->pack_hidden_name(name, is_exported);
830 ret->push_back(Typed_identifier(id_name, NULL, location));
831 if (!this->advance_token()->is_op(OPERATOR_COMMA))
833 just_saw_comma = false;
840 // We saw ID1 "," ID2 "," followed by something which
841 // was not an identifier. We must be seeing the start
842 // of a type, and ID1 and ID2 must be types, and the
843 // parameters don't have names.
844 parameters_have_names = false;
846 else if (this->peek_token()->is_op(OPERATOR_RPAREN))
848 // We saw ID1 "," ID2 ")". ID1 and ID2 must be types,
849 // and the parameters don't have names.
850 parameters_have_names = false;
852 else if (this->peek_token()->is_op(OPERATOR_DOT))
854 // We saw ID1 "," ID2 ".". ID2 must be a package name,
855 // ID1 must be a type, and the parameters don't have
857 parameters_have_names = false;
858 this->unget_token(Token::make_identifier_token(name, is_exported,
861 just_saw_comma = true;
865 // We saw ID1 "," ID2 followed by something other than
866 // ",", ".", or ")". We must be looking at the start of
867 // a type, and ID1 and ID2 must be parameter names.
868 parameters_have_names = true;
871 if (parameters_have_names)
873 go_assert(!just_saw_comma);
874 // We have just seen ID1, ID2 xxx.
876 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
880 error_at(this->location(), "%<...%> only permits one name");
882 this->advance_token();
885 for (size_t i = 0; i < ret->size(); ++i)
886 ret->set_type(i, type);
887 if (!this->peek_token()->is_op(OPERATOR_COMMA))
888 return saw_error ? NULL : ret;
889 if (this->advance_token()->is_op(OPERATOR_RPAREN))
890 return saw_error ? NULL : ret;
894 Typed_identifier_list* tret = new Typed_identifier_list();
895 for (Typed_identifier_list::const_iterator p = ret->begin();
899 Named_object* no = this->gogo_->lookup(p->name(), NULL);
902 no = this->gogo_->add_unknown_name(p->name(),
906 type = no->type_value();
907 else if (no->is_unknown() || no->is_type_declaration())
908 type = Type::make_forward_declaration(no);
911 error_at(p->location(), "expected %<%s%> to be a type",
912 Gogo::message_name(p->name()).c_str());
914 type = Type::make_error_type();
916 tret->push_back(Typed_identifier("", type, p->location()));
921 || this->peek_token()->is_op(OPERATOR_RPAREN))
922 return saw_error ? NULL : ret;
927 bool mix_error = false;
928 this->parameter_decl(parameters_have_names, ret, is_varargs, &mix_error);
929 while (this->peek_token()->is_op(OPERATOR_COMMA))
931 if (is_varargs != NULL && *is_varargs)
933 error_at(this->location(), "%<...%> must be last parameter");
936 if (this->advance_token()->is_op(OPERATOR_RPAREN))
938 this->parameter_decl(parameters_have_names, ret, is_varargs, &mix_error);
942 error_at(location, "invalid named/anonymous mix");
953 // ParameterDecl = [ IdentifierList ] [ "..." ] Type .
956 Parse::parameter_decl(bool parameters_have_names,
957 Typed_identifier_list* til,
961 if (!parameters_have_names)
964 source_location location = this->location();
965 if (!this->peek_token()->is_identifier())
967 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
971 if (is_varargs == NULL)
972 error_at(this->location(), "invalid use of %<...%>");
975 this->advance_token();
976 if (is_varargs == NULL
977 && this->peek_token()->is_op(OPERATOR_RPAREN))
978 type = Type::make_error_type();
981 Type* element_type = this->type();
982 type = Type::make_array_type(element_type, NULL);
988 type = this->type_name(false);
989 if (type->is_error_type()
990 || (!this->peek_token()->is_op(OPERATOR_COMMA)
991 && !this->peek_token()->is_op(OPERATOR_RPAREN)))
994 while (!this->peek_token()->is_op(OPERATOR_COMMA)
995 && !this->peek_token()->is_op(OPERATOR_RPAREN))
996 this->advance_token();
999 if (!type->is_error_type())
1000 til->push_back(Typed_identifier("", type, location));
1004 size_t orig_count = til->size();
1005 if (this->peek_token()->is_identifier())
1006 this->identifier_list(til);
1009 size_t new_count = til->size();
1012 if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
1013 type = this->type();
1016 if (is_varargs == NULL)
1017 error_at(this->location(), "invalid use of %<...%>");
1018 else if (new_count > orig_count + 1)
1019 error_at(this->location(), "%<...%> only permits one name");
1022 this->advance_token();
1023 Type* element_type = this->type();
1024 type = Type::make_array_type(element_type, NULL);
1026 for (size_t i = orig_count; i < new_count; ++i)
1027 til->set_type(i, type);
1031 // Result = Parameters | Type .
1033 // This returns false on a parse error.
1036 Parse::result(Typed_identifier_list** presults)
1038 if (this->peek_token()->is_op(OPERATOR_LPAREN))
1039 return this->parameters(presults, NULL);
1042 source_location location = this->location();
1043 Type* type = this->type();
1044 if (type->is_error_type())
1049 Typed_identifier_list* til = new Typed_identifier_list();
1050 til->push_back(Typed_identifier("", type, location));
1056 // Block = "{" [ StatementList ] "}" .
1058 // Returns the location of the closing brace.
1063 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
1065 source_location loc = this->location();
1066 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1067 && this->advance_token()->is_op(OPERATOR_LCURLY))
1068 error_at(loc, "unexpected semicolon or newline before %<{%>");
1071 error_at(this->location(), "expected %<{%>");
1072 return UNKNOWN_LOCATION;
1076 const Token* token = this->advance_token();
1078 if (!token->is_op(OPERATOR_RCURLY))
1080 this->statement_list();
1081 token = this->peek_token();
1082 if (!token->is_op(OPERATOR_RCURLY))
1084 if (!token->is_eof() || !saw_errors())
1085 error_at(this->location(), "expected %<}%>");
1087 // Skip ahead to the end of the block, in hopes of avoiding
1088 // lots of meaningless errors.
1089 source_location ret = token->location();
1091 while (!token->is_eof())
1093 if (token->is_op(OPERATOR_LCURLY))
1095 else if (token->is_op(OPERATOR_RCURLY))
1100 this->advance_token();
1104 token = this->advance_token();
1105 ret = token->location();
1111 source_location ret = token->location();
1112 this->advance_token();
1116 // InterfaceType = "interface" "{" [ MethodSpecList ] "}" .
1117 // MethodSpecList = MethodSpec { ";" MethodSpec } [ ";" ] .
1120 Parse::interface_type()
1122 go_assert(this->peek_token()->is_keyword(KEYWORD_INTERFACE));
1123 source_location location = this->location();
1125 if (!this->advance_token()->is_op(OPERATOR_LCURLY))
1127 source_location token_loc = this->location();
1128 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1129 && this->advance_token()->is_op(OPERATOR_LCURLY))
1130 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
1133 error_at(this->location(), "expected %<{%>");
1134 return Type::make_error_type();
1137 this->advance_token();
1139 Typed_identifier_list* methods = new Typed_identifier_list();
1140 if (!this->peek_token()->is_op(OPERATOR_RCURLY))
1142 this->method_spec(methods);
1143 while (this->peek_token()->is_op(OPERATOR_SEMICOLON))
1145 if (this->advance_token()->is_op(OPERATOR_RCURLY))
1147 this->method_spec(methods);
1149 if (!this->peek_token()->is_op(OPERATOR_RCURLY))
1151 error_at(this->location(), "expected %<}%>");
1152 while (!this->advance_token()->is_op(OPERATOR_RCURLY))
1154 if (this->peek_token()->is_eof())
1155 return Type::make_error_type();
1159 this->advance_token();
1161 if (methods->empty())
1167 Interface_type* ret = Type::make_interface_type(methods, location);
1168 this->gogo_->record_interface_type(ret);
1172 // MethodSpec = MethodName Signature | InterfaceTypeName .
1173 // MethodName = identifier .
1174 // InterfaceTypeName = TypeName .
1177 Parse::method_spec(Typed_identifier_list* methods)
1179 const Token* token = this->peek_token();
1180 if (!token->is_identifier())
1182 error_at(this->location(), "expected identifier");
1186 std::string name = token->identifier();
1187 bool is_exported = token->is_identifier_exported();
1188 source_location location = token->location();
1190 if (this->advance_token()->is_op(OPERATOR_LPAREN))
1192 // This is a MethodName.
1193 name = this->gogo_->pack_hidden_name(name, is_exported);
1194 Type* type = this->signature(NULL, location);
1197 methods->push_back(Typed_identifier(name, type, location));
1201 this->unget_token(Token::make_identifier_token(name, is_exported,
1203 Type* type = this->type_name(false);
1204 if (type->is_error_type()
1205 || (!this->peek_token()->is_op(OPERATOR_SEMICOLON)
1206 && !this->peek_token()->is_op(OPERATOR_RCURLY)))
1208 if (this->peek_token()->is_op(OPERATOR_COMMA))
1209 error_at(this->location(),
1210 "name list not allowed in interface type");
1212 error_at(location, "expected signature or type name");
1213 token = this->peek_token();
1214 while (!token->is_eof()
1215 && !token->is_op(OPERATOR_SEMICOLON)
1216 && !token->is_op(OPERATOR_RCURLY))
1217 token = this->advance_token();
1220 // This must be an interface type, but we can't check that now.
1221 // We check it and pull out the methods in
1222 // Interface_type::do_verify.
1223 methods->push_back(Typed_identifier("", type, location));
1227 // Declaration = ConstDecl | TypeDecl | VarDecl | FunctionDecl | MethodDecl .
1230 Parse::declaration()
1232 const Token* token = this->peek_token();
1233 if (token->is_keyword(KEYWORD_CONST))
1235 else if (token->is_keyword(KEYWORD_TYPE))
1237 else if (token->is_keyword(KEYWORD_VAR))
1239 else if (token->is_keyword(KEYWORD_FUNC))
1240 this->function_decl();
1243 error_at(this->location(), "expected declaration");
1244 this->advance_token();
1249 Parse::declaration_may_start_here()
1251 const Token* token = this->peek_token();
1252 return (token->is_keyword(KEYWORD_CONST)
1253 || token->is_keyword(KEYWORD_TYPE)
1254 || token->is_keyword(KEYWORD_VAR)
1255 || token->is_keyword(KEYWORD_FUNC));
1258 // Decl<P> = P | "(" [ List<P> ] ")" .
1261 Parse::decl(void (Parse::*pfn)(void*), void* varg)
1263 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
1267 if (!this->advance_token()->is_op(OPERATOR_RPAREN))
1269 this->list(pfn, varg, true);
1270 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
1272 error_at(this->location(), "missing %<)%>");
1273 while (!this->advance_token()->is_op(OPERATOR_RPAREN))
1275 if (this->peek_token()->is_eof())
1280 this->advance_token();
1284 // List<P> = P { ";" P } [ ";" ] .
1286 // In order to pick up the trailing semicolon we need to know what
1287 // might follow. This is either a '}' or a ')'.
1290 Parse::list(void (Parse::*pfn)(void*), void* varg, bool follow_is_paren)
1293 Operator follow = follow_is_paren ? OPERATOR_RPAREN : OPERATOR_RCURLY;
1294 while (this->peek_token()->is_op(OPERATOR_SEMICOLON)
1295 || this->peek_token()->is_op(OPERATOR_COMMA))
1297 if (this->peek_token()->is_op(OPERATOR_COMMA))
1298 error_at(this->location(), "unexpected comma");
1299 if (this->advance_token()->is_op(follow))
1305 // ConstDecl = "const" ( ConstSpec | "(" { ConstSpec ";" } ")" ) .
1310 go_assert(this->peek_token()->is_keyword(KEYWORD_CONST));
1311 this->advance_token();
1314 Type* last_type = NULL;
1315 Expression_list* last_expr_list = NULL;
1317 if (!this->peek_token()->is_op(OPERATOR_LPAREN))
1318 this->const_spec(&last_type, &last_expr_list);
1321 this->advance_token();
1322 while (!this->peek_token()->is_op(OPERATOR_RPAREN))
1324 this->const_spec(&last_type, &last_expr_list);
1325 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
1326 this->advance_token();
1327 else if (!this->peek_token()->is_op(OPERATOR_RPAREN))
1329 error_at(this->location(), "expected %<;%> or %<)%> or newline");
1330 if (!this->skip_past_error(OPERATOR_RPAREN))
1334 this->advance_token();
1337 if (last_expr_list != NULL)
1338 delete last_expr_list;
1341 // ConstSpec = IdentifierList [ [ CompleteType ] "=" ExpressionList ] .
1344 Parse::const_spec(Type** last_type, Expression_list** last_expr_list)
1346 Typed_identifier_list til;
1347 this->identifier_list(&til);
1350 if (this->type_may_start_here())
1352 type = this->type();
1354 *last_expr_list = NULL;
1357 Expression_list *expr_list;
1358 if (!this->peek_token()->is_op(OPERATOR_EQ))
1360 if (*last_expr_list == NULL)
1362 error_at(this->location(), "expected %<=%>");
1366 expr_list = new Expression_list;
1367 for (Expression_list::const_iterator p = (*last_expr_list)->begin();
1368 p != (*last_expr_list)->end();
1370 expr_list->push_back((*p)->copy());
1374 this->advance_token();
1375 expr_list = this->expression_list(NULL, false);
1377 if (*last_expr_list != NULL)
1378 delete *last_expr_list;
1379 *last_expr_list = expr_list;
1382 Expression_list::const_iterator pe = expr_list->begin();
1383 for (Typed_identifier_list::iterator pi = til.begin();
1387 if (pe == expr_list->end())
1389 error_at(this->location(), "not enough initializers");
1395 if (!Gogo::is_sink_name(pi->name()))
1396 this->gogo_->add_constant(*pi, *pe, this->iota_value());
1398 if (pe != expr_list->end())
1399 error_at(this->location(), "too many initializers");
1401 this->increment_iota();
1406 // TypeDecl = "type" Decl<TypeSpec> .
1411 go_assert(this->peek_token()->is_keyword(KEYWORD_TYPE));
1412 this->advance_token();
1413 this->decl(&Parse::type_spec, NULL);
1416 // TypeSpec = identifier Type .
1419 Parse::type_spec(void*)
1421 const Token* token = this->peek_token();
1422 if (!token->is_identifier())
1424 error_at(this->location(), "expected identifier");
1427 std::string name = token->identifier();
1428 bool is_exported = token->is_identifier_exported();
1429 source_location location = token->location();
1430 token = this->advance_token();
1432 // The scope of the type name starts at the point where the
1433 // identifier appears in the source code. We implement this by
1434 // declaring the type before we read the type definition.
1435 Named_object* named_type = NULL;
1438 name = this->gogo_->pack_hidden_name(name, is_exported);
1439 named_type = this->gogo_->declare_type(name, location);
1443 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
1444 type = this->type();
1447 error_at(this->location(),
1448 "unexpected semicolon or newline in type declaration");
1449 type = Type::make_error_type();
1450 this->advance_token();
1453 if (type->is_error_type())
1455 while (!this->peek_token()->is_op(OPERATOR_SEMICOLON)
1456 && !this->peek_token()->is_eof())
1457 this->advance_token();
1462 if (named_type->is_type_declaration())
1464 Type* ftype = type->forwarded();
1465 if (ftype->forward_declaration_type() != NULL
1466 && (ftype->forward_declaration_type()->named_object()
1469 error_at(location, "invalid recursive type");
1470 type = Type::make_error_type();
1473 this->gogo_->define_type(named_type,
1474 Type::make_named_type(named_type, type,
1476 go_assert(named_type->package() == NULL);
1480 // This will probably give a redefinition error.
1481 this->gogo_->add_type(name, type, location);
1486 // VarDecl = "var" Decl<VarSpec> .
1491 go_assert(this->peek_token()->is_keyword(KEYWORD_VAR));
1492 this->advance_token();
1493 this->decl(&Parse::var_spec, NULL);
1496 // VarSpec = IdentifierList
1497 // ( CompleteType [ "=" ExpressionList ] | "=" ExpressionList ) .
1500 Parse::var_spec(void*)
1502 // Get the variable names.
1503 Typed_identifier_list til;
1504 this->identifier_list(&til);
1506 source_location location = this->location();
1509 Expression_list* init = NULL;
1510 if (!this->peek_token()->is_op(OPERATOR_EQ))
1512 type = this->type();
1513 if (type->is_error_type())
1515 while (!this->peek_token()->is_op(OPERATOR_EQ)
1516 && !this->peek_token()->is_op(OPERATOR_SEMICOLON)
1517 && !this->peek_token()->is_eof())
1518 this->advance_token();
1520 if (this->peek_token()->is_op(OPERATOR_EQ))
1522 this->advance_token();
1523 init = this->expression_list(NULL, false);
1528 this->advance_token();
1529 init = this->expression_list(NULL, false);
1532 this->init_vars(&til, type, init, false, location);
1538 // Create variables. TIL is a list of variable names. If TYPE is not
1539 // NULL, it is the type of all the variables. If INIT is not NULL, it
1540 // is an initializer list for the variables.
1543 Parse::init_vars(const Typed_identifier_list* til, Type* type,
1544 Expression_list* init, bool is_coloneq,
1545 source_location location)
1547 // Check for an initialization which can yield multiple values.
1548 if (init != NULL && init->size() == 1 && til->size() > 1)
1550 if (this->init_vars_from_call(til, type, *init->begin(), is_coloneq,
1553 if (this->init_vars_from_map(til, type, *init->begin(), is_coloneq,
1556 if (this->init_vars_from_receive(til, type, *init->begin(), is_coloneq,
1559 if (this->init_vars_from_type_guard(til, type, *init->begin(),
1560 is_coloneq, location))
1564 if (init != NULL && init->size() != til->size())
1566 if (init->empty() || !init->front()->is_error_expression())
1567 error_at(location, "wrong number of initializations");
1570 type = Type::make_error_type();
1573 // Note that INIT was already parsed with the old name bindings, so
1574 // we don't have to worry that it will accidentally refer to the
1575 // newly declared variables.
1577 Expression_list::const_iterator pexpr;
1579 pexpr = init->begin();
1580 bool any_new = false;
1581 for (Typed_identifier_list::const_iterator p = til->begin();
1586 go_assert(pexpr != init->end());
1587 this->init_var(*p, type, init == NULL ? NULL : *pexpr, is_coloneq,
1593 go_assert(pexpr == init->end());
1594 if (is_coloneq && !any_new)
1595 error_at(location, "variables redeclared but no variable is new");
1598 // See if we need to initialize a list of variables from a function
1599 // call. This returns true if we have set up the variables and the
1603 Parse::init_vars_from_call(const Typed_identifier_list* vars, Type* type,
1604 Expression* expr, bool is_coloneq,
1605 source_location location)
1607 Call_expression* call = expr->call_expression();
1611 // This is a function call. We can't check here whether it returns
1612 // the right number of values, but it might. Declare the variables,
1613 // and then assign the results of the call to them.
1615 unsigned int index = 0;
1616 bool any_new = false;
1617 for (Typed_identifier_list::const_iterator pv = vars->begin();
1621 Expression* init = Expression::make_call_result(call, index);
1622 this->init_var(*pv, type, init, is_coloneq, false, &any_new);
1625 if (is_coloneq && !any_new)
1626 error_at(location, "variables redeclared but no variable is new");
1631 // See if we need to initialize a pair of values from a map index
1632 // expression. This returns true if we have set up the variables and
1633 // the initialization.
1636 Parse::init_vars_from_map(const Typed_identifier_list* vars, Type* type,
1637 Expression* expr, bool is_coloneq,
1638 source_location location)
1640 Index_expression* index = expr->index_expression();
1643 if (vars->size() != 2)
1646 // This is an index which is being assigned to two variables. It
1647 // must be a map index. Declare the variables, and then assign the
1648 // results of the map index.
1649 bool any_new = false;
1650 Typed_identifier_list::const_iterator p = vars->begin();
1651 Expression* init = type == NULL ? index : NULL;
1652 Named_object* val_no = this->init_var(*p, type, init, is_coloneq,
1653 type == NULL, &any_new);
1654 if (type == NULL && any_new && val_no->is_variable())
1655 val_no->var_value()->set_type_from_init_tuple();
1656 Expression* val_var = Expression::make_var_reference(val_no, location);
1659 Type* var_type = type;
1660 if (var_type == NULL)
1661 var_type = Type::lookup_bool_type();
1662 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1664 Expression* present_var = Expression::make_var_reference(no, location);
1666 if (is_coloneq && !any_new)
1667 error_at(location, "variables redeclared but no variable is new");
1669 Statement* s = Statement::make_tuple_map_assignment(val_var, present_var,
1672 if (!this->gogo_->in_global_scope())
1673 this->gogo_->add_statement(s);
1674 else if (!val_no->is_sink())
1676 if (val_no->is_variable())
1677 val_no->var_value()->add_preinit_statement(this->gogo_, s);
1679 else if (!no->is_sink())
1681 if (no->is_variable())
1682 no->var_value()->add_preinit_statement(this->gogo_, s);
1686 // Execute the map index expression just so that we can fail if
1688 Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
1690 dummy->var_value()->add_preinit_statement(this->gogo_, s);
1696 // See if we need to initialize a pair of values from a receive
1697 // expression. This returns true if we have set up the variables and
1698 // the initialization.
1701 Parse::init_vars_from_receive(const Typed_identifier_list* vars, Type* type,
1702 Expression* expr, bool is_coloneq,
1703 source_location location)
1705 Receive_expression* receive = expr->receive_expression();
1706 if (receive == NULL)
1708 if (vars->size() != 2)
1711 // This is a receive expression which is being assigned to two
1712 // variables. Declare the variables, and then assign the results of
1714 bool any_new = false;
1715 Typed_identifier_list::const_iterator p = vars->begin();
1716 Expression* init = type == NULL ? receive : NULL;
1717 Named_object* val_no = this->init_var(*p, type, init, is_coloneq,
1718 type == NULL, &any_new);
1719 if (type == NULL && any_new && val_no->is_variable())
1720 val_no->var_value()->set_type_from_init_tuple();
1721 Expression* val_var = Expression::make_var_reference(val_no, location);
1724 Type* var_type = type;
1725 if (var_type == NULL)
1726 var_type = Type::lookup_bool_type();
1727 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1729 Expression* received_var = Expression::make_var_reference(no, location);
1731 if (is_coloneq && !any_new)
1732 error_at(location, "variables redeclared but no variable is new");
1734 Statement* s = Statement::make_tuple_receive_assignment(val_var,
1740 if (!this->gogo_->in_global_scope())
1741 this->gogo_->add_statement(s);
1742 else if (!val_no->is_sink())
1744 if (val_no->is_variable())
1745 val_no->var_value()->add_preinit_statement(this->gogo_, s);
1747 else if (!no->is_sink())
1749 if (no->is_variable())
1750 no->var_value()->add_preinit_statement(this->gogo_, s);
1754 Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
1756 dummy->var_value()->add_preinit_statement(this->gogo_, s);
1762 // See if we need to initialize a pair of values from a type guard
1763 // expression. This returns true if we have set up the variables and
1764 // the initialization.
1767 Parse::init_vars_from_type_guard(const Typed_identifier_list* vars,
1768 Type* type, Expression* expr,
1769 bool is_coloneq, source_location location)
1771 Type_guard_expression* type_guard = expr->type_guard_expression();
1772 if (type_guard == NULL)
1774 if (vars->size() != 2)
1777 // This is a type guard expression which is being assigned to two
1778 // variables. Declare the variables, and then assign the results of
1780 bool any_new = false;
1781 Typed_identifier_list::const_iterator p = vars->begin();
1782 Type* var_type = type;
1783 if (var_type == NULL)
1784 var_type = type_guard->type();
1785 Named_object* val_no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1787 Expression* val_var = Expression::make_var_reference(val_no, location);
1791 if (var_type == NULL)
1792 var_type = Type::lookup_bool_type();
1793 Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
1795 Expression* ok_var = Expression::make_var_reference(no, location);
1797 Expression* texpr = type_guard->expr();
1798 Type* t = type_guard->type();
1799 Statement* s = Statement::make_tuple_type_guard_assignment(val_var, ok_var,
1803 if (is_coloneq && !any_new)
1804 error_at(location, "variables redeclared but no variable is new");
1806 if (!this->gogo_->in_global_scope())
1807 this->gogo_->add_statement(s);
1808 else if (!val_no->is_sink())
1810 if (val_no->is_variable())
1811 val_no->var_value()->add_preinit_statement(this->gogo_, s);
1813 else if (!no->is_sink())
1815 if (no->is_variable())
1816 no->var_value()->add_preinit_statement(this->gogo_, s);
1820 Named_object* dummy = this->create_dummy_global(type, NULL, location);
1821 dummy->var_value()->add_preinit_statement(this->gogo_, s);
1827 // Create a single variable. If IS_COLONEQ is true, we permit
1828 // redeclarations in the same block, and we set *IS_NEW when we find a
1829 // new variable which is not a redeclaration.
1832 Parse::init_var(const Typed_identifier& tid, Type* type, Expression* init,
1833 bool is_coloneq, bool type_from_init, bool* is_new)
1835 source_location location = tid.location();
1837 if (Gogo::is_sink_name(tid.name()))
1839 if (!type_from_init && init != NULL)
1841 if (!this->gogo_->in_global_scope())
1842 this->gogo_->add_statement(Statement::make_statement(init));
1844 return this->create_dummy_global(type, init, location);
1846 return this->gogo_->add_sink();
1851 Named_object* no = this->gogo_->lookup_in_block(tid.name());
1853 && (no->is_variable() || no->is_result_variable()))
1855 // INIT may be NULL even when IS_COLONEQ is true for cases
1856 // like v, ok := x.(int).
1857 if (!type_from_init && init != NULL)
1859 Expression *v = Expression::make_var_reference(no, location);
1860 Statement *s = Statement::make_assignment(v, init, location);
1861 this->gogo_->add_statement(s);
1867 Variable* var = new Variable(type, init, this->gogo_->in_global_scope(),
1868 false, false, location);
1869 Named_object* no = this->gogo_->add_variable(tid.name(), var);
1870 if (!no->is_variable())
1872 // The name is already defined, so we just gave an error.
1873 return this->gogo_->add_sink();
1878 // Create a dummy global variable to force an initializer to be run in
1879 // the right place. This is used when a sink variable is initialized
1883 Parse::create_dummy_global(Type* type, Expression* init,
1884 source_location location)
1886 if (type == NULL && init == NULL)
1887 type = Type::lookup_bool_type();
1888 Variable* var = new Variable(type, init, true, false, false, location);
1891 snprintf(buf, sizeof buf, "_.%d", count);
1893 return this->gogo_->add_variable(buf, var);
1896 // SimpleVarDecl = identifier ":=" Expression .
1898 // We've already seen the identifier.
1900 // FIXME: We also have to implement
1901 // IdentifierList ":=" ExpressionList
1902 // In order to support both "a, b := 1, 0" and "a, b = 1, 0" we accept
1903 // tuple assignments here as well.
1905 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
1908 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
1909 // guard (var := expr.("type") using the literal keyword "type").
1912 Parse::simple_var_decl_or_assignment(const std::string& name,
1913 source_location location,
1914 Range_clause* p_range_clause,
1915 Type_switch* p_type_switch)
1917 Typed_identifier_list til;
1918 til.push_back(Typed_identifier(name, NULL, location));
1920 // We've seen one identifier. If we see a comma now, this could be
1922 if (this->peek_token()->is_op(OPERATOR_COMMA))
1924 go_assert(p_type_switch == NULL);
1927 const Token* token = this->advance_token();
1928 if (!token->is_identifier())
1931 std::string id = token->identifier();
1932 bool is_id_exported = token->is_identifier_exported();
1933 source_location id_location = token->location();
1935 token = this->advance_token();
1936 if (!token->is_op(OPERATOR_COMMA))
1938 if (token->is_op(OPERATOR_COLONEQ))
1940 id = this->gogo_->pack_hidden_name(id, is_id_exported);
1941 til.push_back(Typed_identifier(id, NULL, location));
1944 this->unget_token(Token::make_identifier_token(id,
1950 id = this->gogo_->pack_hidden_name(id, is_id_exported);
1951 til.push_back(Typed_identifier(id, NULL, location));
1954 // We have a comma separated list of identifiers in TIL. If the
1955 // next token is COLONEQ, then this is a simple var decl, and we
1956 // have the complete list of identifiers. If the next token is
1957 // not COLONEQ, then the only valid parse is a tuple assignment.
1958 // The list of identifiers we have so far is really a list of
1959 // expressions. There are more expressions following.
1961 if (!this->peek_token()->is_op(OPERATOR_COLONEQ))
1963 Expression_list* exprs = new Expression_list;
1964 for (Typed_identifier_list::const_iterator p = til.begin();
1967 exprs->push_back(this->id_to_expression(p->name(),
1970 Expression_list* more_exprs = this->expression_list(NULL, true);
1971 for (Expression_list::const_iterator p = more_exprs->begin();
1972 p != more_exprs->end();
1974 exprs->push_back(*p);
1977 this->tuple_assignment(exprs, p_range_clause);
1982 go_assert(this->peek_token()->is_op(OPERATOR_COLONEQ));
1983 const Token* token = this->advance_token();
1985 if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
1987 this->range_clause_decl(&til, p_range_clause);
1991 Expression_list* init;
1992 if (p_type_switch == NULL)
1993 init = this->expression_list(NULL, false);
1996 bool is_type_switch = false;
1997 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true,
2001 p_type_switch->found = true;
2002 p_type_switch->name = name;
2003 p_type_switch->location = location;
2004 p_type_switch->expr = expr;
2008 if (!this->peek_token()->is_op(OPERATOR_COMMA))
2010 init = new Expression_list();
2011 init->push_back(expr);
2015 this->advance_token();
2016 init = this->expression_list(expr, false);
2020 this->init_vars(&til, NULL, init, true, location);
2023 // FunctionDecl = "func" identifier Signature [ Block ] .
2024 // MethodDecl = "func" Receiver identifier Signature [ Block ] .
2027 // FunctionDecl = "func" identifier Signature
2028 // __asm__ "(" string_lit ")" .
2029 // This extension means a function whose real name is the identifier
2033 Parse::function_decl()
2035 go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
2036 source_location location = this->location();
2037 const Token* token = this->advance_token();
2039 Typed_identifier* rec = NULL;
2040 if (token->is_op(OPERATOR_LPAREN))
2042 rec = this->receiver();
2043 token = this->peek_token();
2046 if (!token->is_identifier())
2048 error_at(this->location(), "expected function name");
2053 this->gogo_->pack_hidden_name(token->identifier(),
2054 token->is_identifier_exported());
2056 this->advance_token();
2058 Function_type* fntype = this->signature(rec, this->location());
2062 Named_object* named_object = NULL;
2064 if (this->peek_token()->is_keyword(KEYWORD_ASM))
2066 if (!this->advance_token()->is_op(OPERATOR_LPAREN))
2068 error_at(this->location(), "expected %<(%>");
2071 token = this->advance_token();
2072 if (!token->is_string())
2074 error_at(this->location(), "expected string");
2077 std::string asm_name = token->string_value();
2078 if (!this->advance_token()->is_op(OPERATOR_RPAREN))
2080 error_at(this->location(), "expected %<)%>");
2083 this->advance_token();
2084 if (!Gogo::is_sink_name(name))
2086 named_object = this->gogo_->declare_function(name, fntype, location);
2087 if (named_object->is_function_declaration())
2088 named_object->func_declaration_value()->set_asm_name(asm_name);
2092 // Check for the easy error of a newline before the opening brace.
2093 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
2095 source_location semi_loc = this->location();
2096 if (this->advance_token()->is_op(OPERATOR_LCURLY))
2097 error_at(this->location(),
2098 "unexpected semicolon or newline before %<{%>");
2100 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
2104 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
2106 if (named_object == NULL && !Gogo::is_sink_name(name))
2107 this->gogo_->declare_function(name, fntype, location);
2111 this->gogo_->start_function(name, fntype, true, location);
2112 source_location end_loc = this->block();
2113 this->gogo_->finish_function(end_loc);
2117 // Receiver = "(" [ identifier ] [ "*" ] BaseTypeName ")" .
2118 // BaseTypeName = identifier .
2123 go_assert(this->peek_token()->is_op(OPERATOR_LPAREN));
2126 const Token* token = this->advance_token();
2127 source_location location = token->location();
2128 if (!token->is_op(OPERATOR_MULT))
2130 if (!token->is_identifier())
2132 error_at(this->location(), "method has no receiver");
2133 while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
2134 token = this->advance_token();
2135 if (!token->is_eof())
2136 this->advance_token();
2139 name = token->identifier();
2140 bool is_exported = token->is_identifier_exported();
2141 token = this->advance_token();
2142 if (!token->is_op(OPERATOR_DOT) && !token->is_op(OPERATOR_RPAREN))
2144 // An identifier followed by something other than a dot or a
2145 // right parenthesis must be a receiver name followed by a
2147 name = this->gogo_->pack_hidden_name(name, is_exported);
2151 // This must be a type name.
2152 this->unget_token(Token::make_identifier_token(name, is_exported,
2154 token = this->peek_token();
2159 // Here the receiver name is in NAME (it is empty if the receiver is
2160 // unnamed) and TOKEN is the first token in the type.
2162 bool is_pointer = false;
2163 if (token->is_op(OPERATOR_MULT))
2166 token = this->advance_token();
2169 if (!token->is_identifier())
2171 error_at(this->location(), "expected receiver name or type");
2172 int c = token->is_op(OPERATOR_LPAREN) ? 1 : 0;
2173 while (!token->is_eof())
2175 token = this->advance_token();
2176 if (token->is_op(OPERATOR_LPAREN))
2178 else if (token->is_op(OPERATOR_RPAREN))
2185 if (!token->is_eof())
2186 this->advance_token();
2190 Type* type = this->type_name(true);
2192 if (is_pointer && !type->is_error_type())
2193 type = Type::make_pointer_type(type);
2195 if (this->peek_token()->is_op(OPERATOR_RPAREN))
2196 this->advance_token();
2199 if (this->peek_token()->is_op(OPERATOR_COMMA))
2200 error_at(this->location(), "method has multiple receivers");
2202 error_at(this->location(), "expected %<)%>");
2203 while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
2204 token = this->advance_token();
2205 if (!token->is_eof())
2206 this->advance_token();
2210 return new Typed_identifier(name, type, location);
2213 // Operand = Literal | QualifiedIdent | MethodExpr | "(" Expression ")" .
2214 // Literal = BasicLit | CompositeLit | FunctionLit .
2215 // BasicLit = int_lit | float_lit | imaginary_lit | char_lit | string_lit .
2217 // If MAY_BE_SINK is true, this operand may be "_".
2220 Parse::operand(bool may_be_sink)
2222 const Token* token = this->peek_token();
2224 switch (token->classification())
2226 case Token::TOKEN_IDENTIFIER:
2228 source_location location = token->location();
2229 std::string id = token->identifier();
2230 bool is_exported = token->is_identifier_exported();
2231 std::string packed = this->gogo_->pack_hidden_name(id, is_exported);
2233 Named_object* in_function;
2234 Named_object* named_object = this->gogo_->lookup(packed, &in_function);
2236 Package* package = NULL;
2237 if (named_object != NULL && named_object->is_package())
2239 if (!this->advance_token()->is_op(OPERATOR_DOT)
2240 || !this->advance_token()->is_identifier())
2242 error_at(location, "unexpected reference to package");
2243 return Expression::make_error(location);
2245 package = named_object->package_value();
2246 package->set_used();
2247 id = this->peek_token()->identifier();
2248 is_exported = this->peek_token()->is_identifier_exported();
2249 packed = this->gogo_->pack_hidden_name(id, is_exported);
2250 named_object = package->lookup(packed);
2251 location = this->location();
2252 go_assert(in_function == NULL);
2255 this->advance_token();
2257 if (named_object != NULL
2258 && named_object->is_type()
2259 && !named_object->type_value()->is_visible())
2261 go_assert(package != NULL);
2262 error_at(location, "invalid reference to hidden type %<%s.%s%>",
2263 Gogo::message_name(package->name()).c_str(),
2264 Gogo::message_name(id).c_str());
2265 return Expression::make_error(location);
2269 if (named_object == NULL)
2271 if (package != NULL)
2273 std::string n1 = Gogo::message_name(package->name());
2274 std::string n2 = Gogo::message_name(id);
2277 ("invalid reference to unexported identifier "
2279 n1.c_str(), n2.c_str());
2282 "reference to undefined identifier %<%s.%s%>",
2283 n1.c_str(), n2.c_str());
2284 return Expression::make_error(location);
2287 named_object = this->gogo_->add_unknown_name(packed, location);
2290 if (in_function != NULL
2291 && in_function != this->gogo_->current_function()
2292 && (named_object->is_variable()
2293 || named_object->is_result_variable()))
2294 return this->enclosing_var_reference(in_function, named_object,
2297 switch (named_object->classification())
2299 case Named_object::NAMED_OBJECT_CONST:
2300 return Expression::make_const_reference(named_object, location);
2301 case Named_object::NAMED_OBJECT_TYPE:
2302 return Expression::make_type(named_object->type_value(), location);
2303 case Named_object::NAMED_OBJECT_TYPE_DECLARATION:
2305 Type* t = Type::make_forward_declaration(named_object);
2306 return Expression::make_type(t, location);
2308 case Named_object::NAMED_OBJECT_VAR:
2309 case Named_object::NAMED_OBJECT_RESULT_VAR:
2310 return Expression::make_var_reference(named_object, location);
2311 case Named_object::NAMED_OBJECT_SINK:
2313 return Expression::make_sink(location);
2316 error_at(location, "cannot use _ as value");
2317 return Expression::make_error(location);
2319 case Named_object::NAMED_OBJECT_FUNC:
2320 case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
2321 return Expression::make_func_reference(named_object, NULL,
2323 case Named_object::NAMED_OBJECT_UNKNOWN:
2324 return Expression::make_unknown_reference(named_object, location);
2331 case Token::TOKEN_STRING:
2332 ret = Expression::make_string(token->string_value(), token->location());
2333 this->advance_token();
2336 case Token::TOKEN_INTEGER:
2337 ret = Expression::make_integer(token->integer_value(), NULL,
2339 this->advance_token();
2342 case Token::TOKEN_FLOAT:
2343 ret = Expression::make_float(token->float_value(), NULL,
2345 this->advance_token();
2348 case Token::TOKEN_IMAGINARY:
2351 mpfr_init_set_ui(zero, 0, GMP_RNDN);
2352 ret = Expression::make_complex(&zero, token->imaginary_value(),
2353 NULL, token->location());
2355 this->advance_token();
2359 case Token::TOKEN_KEYWORD:
2360 switch (token->keyword())
2363 return this->function_lit();
2365 case KEYWORD_INTERFACE:
2367 case KEYWORD_STRUCT:
2369 source_location location = token->location();
2370 return Expression::make_type(this->type(), location);
2377 case Token::TOKEN_OPERATOR:
2378 if (token->is_op(OPERATOR_LPAREN))
2380 this->advance_token();
2381 ret = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2382 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2383 error_at(this->location(), "missing %<)%>");
2385 this->advance_token();
2388 else if (token->is_op(OPERATOR_LSQUARE))
2390 // Here we call array_type directly, as this is the only
2391 // case where an ellipsis is permitted for an array type.
2392 source_location location = token->location();
2393 return Expression::make_type(this->array_type(true), location);
2401 error_at(this->location(), "expected operand");
2402 return Expression::make_error(this->location());
2405 // Handle a reference to a variable in an enclosing function. We add
2406 // it to a list of such variables. We return a reference to a field
2407 // in a struct which will be passed on the static chain when calling
2408 // the current function.
2411 Parse::enclosing_var_reference(Named_object* in_function, Named_object* var,
2412 source_location location)
2414 go_assert(var->is_variable() || var->is_result_variable());
2416 Named_object* this_function = this->gogo_->current_function();
2417 Named_object* closure = this_function->func_value()->closure_var();
2419 Enclosing_var ev(var, in_function, this->enclosing_vars_.size());
2420 std::pair<Enclosing_vars::iterator, bool> ins =
2421 this->enclosing_vars_.insert(ev);
2424 // This is a variable we have not seen before. Add a new field
2425 // to the closure type.
2426 this_function->func_value()->add_closure_field(var, location);
2429 Expression* closure_ref = Expression::make_var_reference(closure,
2431 closure_ref = Expression::make_unary(OPERATOR_MULT, closure_ref, location);
2433 // The closure structure holds pointers to the variables, so we need
2434 // to introduce an indirection.
2435 Expression* e = Expression::make_field_reference(closure_ref,
2438 e = Expression::make_unary(OPERATOR_MULT, e, location);
2442 // CompositeLit = LiteralType LiteralValue .
2443 // LiteralType = StructType | ArrayType | "[" "..." "]" ElementType |
2444 // SliceType | MapType | TypeName .
2445 // LiteralValue = "{" [ ElementList [ "," ] ] "}" .
2446 // ElementList = Element { "," Element } .
2447 // Element = [ Key ":" ] Value .
2448 // Key = Expression .
2449 // Value = Expression | LiteralValue .
2451 // We have already seen the type if there is one, and we are now
2452 // looking at the LiteralValue. The case "[" "..." "]" ElementType
2453 // will be seen here as an array type whose length is "nil". The
2454 // DEPTH parameter is non-zero if this is an embedded composite
2455 // literal and the type was omitted. It gives the number of steps up
2456 // to the type which was provided. E.g., in [][]int{{1}} it will be
2457 // 1. In [][][]int{{{1}}} it will be 2.
2460 Parse::composite_lit(Type* type, int depth, source_location location)
2462 go_assert(this->peek_token()->is_op(OPERATOR_LCURLY));
2463 this->advance_token();
2465 if (this->peek_token()->is_op(OPERATOR_RCURLY))
2467 this->advance_token();
2468 return Expression::make_composite_literal(type, depth, false, NULL,
2472 bool has_keys = false;
2473 Expression_list* vals = new Expression_list;
2477 bool is_type_omitted = false;
2479 const Token* token = this->peek_token();
2481 if (!token->is_op(OPERATOR_LCURLY))
2482 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2485 // This must be a composite literal inside another composite
2486 // literal, with the type omitted for the inner one.
2487 val = this->composite_lit(type, depth + 1, token->location());
2488 is_type_omitted = true;
2491 token = this->peek_token();
2492 if (!token->is_op(OPERATOR_COLON))
2495 vals->push_back(NULL);
2499 if (is_type_omitted && !val->is_error_expression())
2501 error_at(this->location(), "unexpected %<:%>");
2502 val = Expression::make_error(this->location());
2505 this->advance_token();
2507 if (!has_keys && !vals->empty())
2509 Expression_list* newvals = new Expression_list;
2510 for (Expression_list::const_iterator p = vals->begin();
2514 newvals->push_back(NULL);
2515 newvals->push_back(*p);
2522 if (val->unknown_expression() != NULL)
2523 val->unknown_expression()->set_is_composite_literal_key();
2525 vals->push_back(val);
2527 if (!token->is_op(OPERATOR_LCURLY))
2528 val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2531 // This must be a composite literal inside another
2532 // composite literal, with the type omitted for the
2534 val = this->composite_lit(type, depth + 1, token->location());
2537 token = this->peek_token();
2540 vals->push_back(val);
2542 if (token->is_op(OPERATOR_COMMA))
2544 if (this->advance_token()->is_op(OPERATOR_RCURLY))
2546 this->advance_token();
2550 else if (token->is_op(OPERATOR_RCURLY))
2552 this->advance_token();
2557 error_at(this->location(), "expected %<,%> or %<}%>");
2560 while (!token->is_eof()
2561 && (depth > 0 || !token->is_op(OPERATOR_RCURLY)))
2563 if (token->is_op(OPERATOR_LCURLY))
2565 else if (token->is_op(OPERATOR_RCURLY))
2567 token = this->advance_token();
2569 if (token->is_op(OPERATOR_RCURLY))
2570 this->advance_token();
2572 return Expression::make_error(location);
2576 return Expression::make_composite_literal(type, depth, has_keys, vals,
2580 // FunctionLit = "func" Signature Block .
2583 Parse::function_lit()
2585 source_location location = this->location();
2586 go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
2587 this->advance_token();
2589 Enclosing_vars hold_enclosing_vars;
2590 hold_enclosing_vars.swap(this->enclosing_vars_);
2592 Function_type* type = this->signature(NULL, location);
2594 type = Type::make_function_type(NULL, NULL, NULL, location);
2596 // For a function literal, the next token must be a '{'. If we
2597 // don't see that, then we may have a type expression.
2598 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
2599 return Expression::make_type(type, location);
2601 Bc_stack* hold_break_stack = this->break_stack_;
2602 Bc_stack* hold_continue_stack = this->continue_stack_;
2603 this->break_stack_ = NULL;
2604 this->continue_stack_ = NULL;
2606 Named_object* no = this->gogo_->start_function("", type, true, location);
2608 source_location end_loc = this->block();
2610 this->gogo_->finish_function(end_loc);
2612 if (this->break_stack_ != NULL)
2613 delete this->break_stack_;
2614 if (this->continue_stack_ != NULL)
2615 delete this->continue_stack_;
2616 this->break_stack_ = hold_break_stack;
2617 this->continue_stack_ = hold_continue_stack;
2619 hold_enclosing_vars.swap(this->enclosing_vars_);
2621 Expression* closure = this->create_closure(no, &hold_enclosing_vars,
2624 return Expression::make_func_reference(no, closure, location);
2627 // Create a closure for the nested function FUNCTION. This is based
2628 // on ENCLOSING_VARS, which is a list of all variables defined in
2629 // enclosing functions and referenced from FUNCTION. A closure is the
2630 // address of a struct which contains the addresses of all the
2631 // referenced variables. This returns NULL if no closure is required.
2634 Parse::create_closure(Named_object* function, Enclosing_vars* enclosing_vars,
2635 source_location location)
2637 if (enclosing_vars->empty())
2640 // Get the variables in order by their field index.
2642 size_t enclosing_var_count = enclosing_vars->size();
2643 std::vector<Enclosing_var> ev(enclosing_var_count);
2644 for (Enclosing_vars::const_iterator p = enclosing_vars->begin();
2645 p != enclosing_vars->end();
2647 ev[p->index()] = *p;
2649 // Build an initializer for a composite literal of the closure's
2652 Named_object* enclosing_function = this->gogo_->current_function();
2653 Expression_list* initializer = new Expression_list;
2654 for (size_t i = 0; i < enclosing_var_count; ++i)
2656 go_assert(ev[i].index() == i);
2657 Named_object* var = ev[i].var();
2659 if (ev[i].in_function() == enclosing_function)
2660 ref = Expression::make_var_reference(var, location);
2662 ref = this->enclosing_var_reference(ev[i].in_function(), var,
2664 Expression* refaddr = Expression::make_unary(OPERATOR_AND, ref,
2666 initializer->push_back(refaddr);
2669 Named_object* closure_var = function->func_value()->closure_var();
2670 Struct_type* st = closure_var->var_value()->type()->deref()->struct_type();
2671 Expression* cv = Expression::make_struct_composite_literal(st, initializer,
2673 return Expression::make_heap_composite(cv, location);
2676 // PrimaryExpr = Operand { Selector | Index | Slice | TypeGuard | Call } .
2678 // If MAY_BE_SINK is true, this expression may be "_".
2680 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
2683 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2684 // guard (var := expr.("type") using the literal keyword "type").
2687 Parse::primary_expr(bool may_be_sink, bool may_be_composite_lit,
2688 bool* is_type_switch)
2690 source_location start_loc = this->location();
2691 bool is_parenthesized = this->peek_token()->is_op(OPERATOR_LPAREN);
2693 Expression* ret = this->operand(may_be_sink);
2695 // An unknown name followed by a curly brace must be a composite
2696 // literal, and the unknown name must be a type.
2697 if (may_be_composite_lit
2698 && !is_parenthesized
2699 && ret->unknown_expression() != NULL
2700 && this->peek_token()->is_op(OPERATOR_LCURLY))
2702 Named_object* no = ret->unknown_expression()->named_object();
2703 Type* type = Type::make_forward_declaration(no);
2704 ret = Expression::make_type(type, ret->location());
2707 // We handle composite literals and type casts here, as it is the
2708 // easiest way to handle types which are in parentheses, as in
2710 if (ret->is_type_expression())
2712 if (this->peek_token()->is_op(OPERATOR_LCURLY))
2714 if (is_parenthesized)
2716 "cannot parenthesize type in composite literal");
2717 ret = this->composite_lit(ret->type(), 0, ret->location());
2719 else if (this->peek_token()->is_op(OPERATOR_LPAREN))
2721 source_location loc = this->location();
2722 this->advance_token();
2723 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true,
2725 if (this->peek_token()->is_op(OPERATOR_ELLIPSIS))
2727 error_at(this->location(),
2728 "invalid use of %<...%> in type conversion");
2729 this->advance_token();
2731 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2732 error_at(this->location(), "expected %<)%>");
2734 this->advance_token();
2735 if (expr->is_error_expression())
2737 ret = Expression::make_cast(ret->type(), expr, loc);
2743 const Token* token = this->peek_token();
2744 if (token->is_op(OPERATOR_LPAREN))
2745 ret = this->call(this->verify_not_sink(ret));
2746 else if (token->is_op(OPERATOR_DOT))
2748 ret = this->selector(this->verify_not_sink(ret), is_type_switch);
2749 if (is_type_switch != NULL && *is_type_switch)
2752 else if (token->is_op(OPERATOR_LSQUARE))
2753 ret = this->index(this->verify_not_sink(ret));
2761 // Selector = "." identifier .
2762 // TypeGuard = "." "(" QualifiedIdent ")" .
2764 // Note that Operand can expand to QualifiedIdent, which contains a
2765 // ".". That is handled directly in operand when it sees a package
2768 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2769 // guard (var := expr.("type") using the literal keyword "type").
2772 Parse::selector(Expression* left, bool* is_type_switch)
2774 go_assert(this->peek_token()->is_op(OPERATOR_DOT));
2775 source_location location = this->location();
2777 const Token* token = this->advance_token();
2778 if (token->is_identifier())
2780 // This could be a field in a struct, or a method in an
2781 // interface, or a method associated with a type. We can't know
2782 // which until we have seen all the types.
2784 this->gogo_->pack_hidden_name(token->identifier(),
2785 token->is_identifier_exported());
2786 if (token->identifier() == "_")
2788 error_at(this->location(), "invalid use of %<_%>");
2789 name = this->gogo_->pack_hidden_name("blank", false);
2791 this->advance_token();
2792 return Expression::make_selector(left, name, location);
2794 else if (token->is_op(OPERATOR_LPAREN))
2796 this->advance_token();
2798 if (!this->peek_token()->is_keyword(KEYWORD_TYPE))
2799 type = this->type();
2802 if (is_type_switch != NULL)
2803 *is_type_switch = true;
2806 error_at(this->location(),
2807 "use of %<.(type)%> outside type switch");
2808 type = Type::make_error_type();
2810 this->advance_token();
2812 if (!this->peek_token()->is_op(OPERATOR_RPAREN))
2813 error_at(this->location(), "missing %<)%>");
2815 this->advance_token();
2816 if (is_type_switch != NULL && *is_type_switch)
2818 return Expression::make_type_guard(left, type, location);
2822 error_at(this->location(), "expected identifier or %<(%>");
2827 // Index = "[" Expression "]" .
2828 // Slice = "[" Expression ":" [ Expression ] "]" .
2831 Parse::index(Expression* expr)
2833 source_location location = this->location();
2834 go_assert(this->peek_token()->is_op(OPERATOR_LSQUARE));
2835 this->advance_token();
2838 if (!this->peek_token()->is_op(OPERATOR_COLON))
2839 start = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2843 mpz_init_set_ui(zero, 0);
2844 start = Expression::make_integer(&zero, NULL, location);
2848 Expression* end = NULL;
2849 if (this->peek_token()->is_op(OPERATOR_COLON))
2851 // We use nil to indicate a missing high expression.
2852 if (this->advance_token()->is_op(OPERATOR_RSQUARE))
2853 end = Expression::make_nil(this->location());
2855 end = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
2857 if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
2858 error_at(this->location(), "missing %<]%>");
2860 this->advance_token();
2861 return Expression::make_index(expr, start, end, location);
2864 // Call = "(" [ ArgumentList [ "," ] ] ")" .
2865 // ArgumentList = ExpressionList [ "..." ] .
2868 Parse::call(Expression* func)
2870 go_assert(this->peek_token()->is_op(OPERATOR_LPAREN));
2871 Expression_list* args = NULL;
2872 bool is_varargs = false;
2873 const Token* token = this->advance_token();
2874 if (!token->is_op(OPERATOR_RPAREN))
2876 args = this->expression_list(NULL, false);
2877 token = this->peek_token();
2878 if (token->is_op(OPERATOR_ELLIPSIS))
2881 token = this->advance_token();
2884 if (token->is_op(OPERATOR_COMMA))
2885 token = this->advance_token();
2886 if (!token->is_op(OPERATOR_RPAREN))
2887 error_at(this->location(), "missing %<)%>");
2889 this->advance_token();
2890 if (func->is_error_expression())
2892 return Expression::make_call(func, args, is_varargs, func->location());
2895 // Return an expression for a single unqualified identifier.
2898 Parse::id_to_expression(const std::string& name, source_location location)
2900 Named_object* in_function;
2901 Named_object* named_object = this->gogo_->lookup(name, &in_function);
2902 if (named_object == NULL)
2903 named_object = this->gogo_->add_unknown_name(name, location);
2905 if (in_function != NULL
2906 && in_function != this->gogo_->current_function()
2907 && (named_object->is_variable() || named_object->is_result_variable()))
2908 return this->enclosing_var_reference(in_function, named_object,
2911 switch (named_object->classification())
2913 case Named_object::NAMED_OBJECT_CONST:
2914 return Expression::make_const_reference(named_object, location);
2915 case Named_object::NAMED_OBJECT_VAR:
2916 case Named_object::NAMED_OBJECT_RESULT_VAR:
2917 return Expression::make_var_reference(named_object, location);
2918 case Named_object::NAMED_OBJECT_SINK:
2919 return Expression::make_sink(location);
2920 case Named_object::NAMED_OBJECT_FUNC:
2921 case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
2922 return Expression::make_func_reference(named_object, NULL, location);
2923 case Named_object::NAMED_OBJECT_UNKNOWN:
2924 return Expression::make_unknown_reference(named_object, location);
2926 error_at(this->location(), "unexpected type of identifier");
2927 return Expression::make_error(location);
2931 // Expression = UnaryExpr { binary_op Expression } .
2933 // PRECEDENCE is the precedence of the current operator.
2935 // If MAY_BE_SINK is true, this expression may be "_".
2937 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
2940 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
2941 // guard (var := expr.("type") using the literal keyword "type").
2944 Parse::expression(Precedence precedence, bool may_be_sink,
2945 bool may_be_composite_lit, bool* is_type_switch)
2947 Expression* left = this->unary_expr(may_be_sink, may_be_composite_lit,
2952 if (is_type_switch != NULL && *is_type_switch)
2955 const Token* token = this->peek_token();
2956 if (token->classification() != Token::TOKEN_OPERATOR)
2962 Precedence right_precedence;
2963 switch (token->op())
2966 right_precedence = PRECEDENCE_OROR;
2968 case OPERATOR_ANDAND:
2969 right_precedence = PRECEDENCE_ANDAND;
2972 case OPERATOR_NOTEQ:
2977 right_precedence = PRECEDENCE_RELOP;
2980 case OPERATOR_MINUS:
2983 right_precedence = PRECEDENCE_ADDOP;
2988 case OPERATOR_LSHIFT:
2989 case OPERATOR_RSHIFT:
2991 case OPERATOR_BITCLEAR:
2992 right_precedence = PRECEDENCE_MULOP;
2995 right_precedence = PRECEDENCE_INVALID;
2999 if (right_precedence == PRECEDENCE_INVALID)
3005 Operator op = token->op();
3006 source_location binop_location = token->location();
3008 if (precedence >= right_precedence)
3010 // We've already seen A * B, and we see + C. We want to
3011 // return so that A * B becomes a group.
3015 this->advance_token();
3017 left = this->verify_not_sink(left);
3018 Expression* right = this->expression(right_precedence, false,
3019 may_be_composite_lit,
3021 left = Expression::make_binary(op, left, right, binop_location);
3026 Parse::expression_may_start_here()
3028 const Token* token = this->peek_token();
3029 switch (token->classification())
3031 case Token::TOKEN_INVALID:
3032 case Token::TOKEN_EOF:
3034 case Token::TOKEN_KEYWORD:
3035 switch (token->keyword())
3040 case KEYWORD_STRUCT:
3041 case KEYWORD_INTERFACE:
3046 case Token::TOKEN_IDENTIFIER:
3048 case Token::TOKEN_STRING:
3050 case Token::TOKEN_OPERATOR:
3051 switch (token->op())
3054 case OPERATOR_MINUS:
3058 case OPERATOR_CHANOP:
3060 case OPERATOR_LPAREN:
3061 case OPERATOR_LSQUARE:
3066 case Token::TOKEN_INTEGER:
3067 case Token::TOKEN_FLOAT:
3068 case Token::TOKEN_IMAGINARY:
3075 // UnaryExpr = unary_op UnaryExpr | PrimaryExpr .
3077 // If MAY_BE_SINK is true, this expression may be "_".
3079 // If MAY_BE_COMPOSITE_LIT is true, this expression may be a composite
3082 // If IS_TYPE_SWITCH is not NULL, this will recognize a type switch
3083 // guard (var := expr.("type") using the literal keyword "type").
3086 Parse::unary_expr(bool may_be_sink, bool may_be_composite_lit,
3087 bool* is_type_switch)
3089 const Token* token = this->peek_token();
3090 if (token->is_op(OPERATOR_PLUS)
3091 || token->is_op(OPERATOR_MINUS)
3092 || token->is_op(OPERATOR_NOT)
3093 || token->is_op(OPERATOR_XOR)
3094 || token->is_op(OPERATOR_CHANOP)
3095 || token->is_op(OPERATOR_MULT)
3096 || token->is_op(OPERATOR_AND))
3098 source_location location = token->location();
3099 Operator op = token->op();
3100 this->advance_token();
3102 if (op == OPERATOR_CHANOP
3103 && this->peek_token()->is_keyword(KEYWORD_CHAN))
3105 // This is "<- chan" which must be the start of a type.
3106 this->unget_token(Token::make_operator_token(op, location));
3107 return Expression::make_type(this->type(), location);
3110 Expression* expr = this->unary_expr(false, may_be_composite_lit, NULL);
3111 if (expr->is_error_expression())
3113 else if (op == OPERATOR_MULT && expr->is_type_expression())
3114 expr = Expression::make_type(Type::make_pointer_type(expr->type()),
3116 else if (op == OPERATOR_AND && expr->is_composite_literal())
3117 expr = Expression::make_heap_composite(expr, location);
3118 else if (op != OPERATOR_CHANOP)
3119 expr = Expression::make_unary(op, expr, location);
3121 expr = Expression::make_receive(expr, location);
3125 return this->primary_expr(may_be_sink, may_be_composite_lit,
3130 // Declaration | LabeledStmt | SimpleStmt |
3131 // GoStmt | ReturnStmt | BreakStmt | ContinueStmt | GotoStmt |
3132 // FallthroughStmt | Block | IfStmt | SwitchStmt | SelectStmt | ForStmt |
3135 // LABEL is the label of this statement if it has one.
3138 Parse::statement(Label* label)
3140 const Token* token = this->peek_token();
3141 switch (token->classification())
3143 case Token::TOKEN_KEYWORD:
3145 switch (token->keyword())
3150 this->declaration();
3154 case KEYWORD_STRUCT:
3155 case KEYWORD_INTERFACE:
3156 this->simple_stat(true, NULL, NULL, NULL);
3160 this->go_or_defer_stat();
3162 case KEYWORD_RETURN:
3163 this->return_stat();
3168 case KEYWORD_CONTINUE:
3169 this->continue_stat();
3177 case KEYWORD_SWITCH:
3178 this->switch_stat(label);
3180 case KEYWORD_SELECT:
3181 this->select_stat(label);
3184 this->for_stat(label);
3187 error_at(this->location(), "expected statement");
3188 this->advance_token();
3194 case Token::TOKEN_IDENTIFIER:
3196 std::string identifier = token->identifier();
3197 bool is_exported = token->is_identifier_exported();
3198 source_location location = token->location();
3199 if (this->advance_token()->is_op(OPERATOR_COLON))
3201 this->advance_token();
3202 this->labeled_stmt(identifier, location);
3206 this->unget_token(Token::make_identifier_token(identifier,
3209 this->simple_stat(true, NULL, NULL, NULL);
3214 case Token::TOKEN_OPERATOR:
3215 if (token->is_op(OPERATOR_LCURLY))
3217 source_location location = token->location();
3218 this->gogo_->start_block(location);
3219 source_location end_loc = this->block();
3220 this->gogo_->add_block(this->gogo_->finish_block(end_loc),
3223 else if (!token->is_op(OPERATOR_SEMICOLON))
3224 this->simple_stat(true, NULL, NULL, NULL);
3227 case Token::TOKEN_STRING:
3228 case Token::TOKEN_INTEGER:
3229 case Token::TOKEN_FLOAT:
3230 case Token::TOKEN_IMAGINARY:
3231 this->simple_stat(true, NULL, NULL, NULL);
3235 error_at(this->location(), "expected statement");
3236 this->advance_token();
3242 Parse::statement_may_start_here()
3244 const Token* token = this->peek_token();
3245 switch (token->classification())
3247 case Token::TOKEN_KEYWORD:
3249 switch (token->keyword())
3256 case KEYWORD_STRUCT:
3257 case KEYWORD_INTERFACE:
3260 case KEYWORD_RETURN:
3262 case KEYWORD_CONTINUE:
3265 case KEYWORD_SWITCH:
3266 case KEYWORD_SELECT:
3276 case Token::TOKEN_IDENTIFIER:
3279 case Token::TOKEN_OPERATOR:
3280 if (token->is_op(OPERATOR_LCURLY)
3281 || token->is_op(OPERATOR_SEMICOLON))
3284 return this->expression_may_start_here();
3286 case Token::TOKEN_STRING:
3287 case Token::TOKEN_INTEGER:
3288 case Token::TOKEN_FLOAT:
3289 case Token::TOKEN_IMAGINARY:
3297 // LabeledStmt = Label ":" Statement .
3298 // Label = identifier .
3301 Parse::labeled_stmt(const std::string& label_name, source_location location)
3303 Label* label = this->gogo_->add_label_definition(label_name, location);
3305 if (this->peek_token()->is_op(OPERATOR_RCURLY))
3307 // This is a label at the end of a block. A program is
3308 // permitted to omit a semicolon here.
3312 if (!this->statement_may_start_here())
3314 // Mark the label as used to avoid a useless error about an
3316 label->set_is_used();
3318 error_at(location, "missing statement after label");
3319 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
3324 this->statement(label);
3327 // SimpleStmt = EmptyStmt | ExpressionStmt | SendStmt | IncDecStmt |
3328 // Assignment | ShortVarDecl .
3330 // EmptyStmt was handled in Parse::statement.
3332 // In order to make this work for if and switch statements, if
3333 // RETURN_EXP is not NULL, and we see an ExpressionStat, we return the
3334 // expression rather than adding an expression statement to the
3335 // current block. If we see something other than an ExpressionStat,
3336 // we add the statement, set *RETURN_EXP to true if we saw a send
3337 // statement, and return NULL. The handling of send statements is for
3338 // better error messages.
3340 // If P_RANGE_CLAUSE is not NULL, then this will recognize a
3343 // If P_TYPE_SWITCH is not NULL, this will recognize a type switch
3344 // guard (var := expr.("type") using the literal keyword "type").
3347 Parse::simple_stat(bool may_be_composite_lit, bool* return_exp,
3348 Range_clause* p_range_clause, Type_switch* p_type_switch)
3350 const Token* token = this->peek_token();
3352 // An identifier follow by := is a SimpleVarDecl.
3353 if (token->is_identifier())
3355 std::string identifier = token->identifier();
3356 bool is_exported = token->is_identifier_exported();
3357 source_location location = token->location();
3359 token = this->advance_token();
3360 if (token->is_op(OPERATOR_COLONEQ)
3361 || token->is_op(OPERATOR_COMMA))
3363 identifier = this->gogo_->pack_hidden_name(identifier, is_exported);
3364 this->simple_var_decl_or_assignment(identifier, location,
3366 (token->is_op(OPERATOR_COLONEQ)
3372 this->unget_token(Token::make_identifier_token(identifier, is_exported,
3376 Expression* exp = this->expression(PRECEDENCE_NORMAL, true,
3377 may_be_composite_lit,
3378 (p_type_switch == NULL
3380 : &p_type_switch->found));
3381 if (p_type_switch != NULL && p_type_switch->found)
3383 p_type_switch->name.clear();
3384 p_type_switch->location = exp->location();
3385 p_type_switch->expr = this->verify_not_sink(exp);
3388 token = this->peek_token();
3389 if (token->is_op(OPERATOR_CHANOP))
3391 this->send_stmt(this->verify_not_sink(exp));
3392 if (return_exp != NULL)
3395 else if (token->is_op(OPERATOR_PLUSPLUS)
3396 || token->is_op(OPERATOR_MINUSMINUS))
3397 this->inc_dec_stat(this->verify_not_sink(exp));
3398 else if (token->is_op(OPERATOR_COMMA)
3399 || token->is_op(OPERATOR_EQ))
3400 this->assignment(exp, p_range_clause);
3401 else if (token->is_op(OPERATOR_PLUSEQ)
3402 || token->is_op(OPERATOR_MINUSEQ)
3403 || token->is_op(OPERATOR_OREQ)
3404 || token->is_op(OPERATOR_XOREQ)
3405 || token->is_op(OPERATOR_MULTEQ)
3406 || token->is_op(OPERATOR_DIVEQ)
3407 || token->is_op(OPERATOR_MODEQ)
3408 || token->is_op(OPERATOR_LSHIFTEQ)
3409 || token->is_op(OPERATOR_RSHIFTEQ)
3410 || token->is_op(OPERATOR_ANDEQ)
3411 || token->is_op(OPERATOR_BITCLEAREQ))
3412 this->assignment(this->verify_not_sink(exp), p_range_clause);
3413 else if (return_exp != NULL)
3414 return this->verify_not_sink(exp);
3416 this->expression_stat(this->verify_not_sink(exp));
3422 Parse::simple_stat_may_start_here()
3424 return this->expression_may_start_here();
3427 // Parse { Statement ";" } which is used in a few places. The list of
3428 // statements may end with a right curly brace, in which case the
3429 // semicolon may be omitted.
3432 Parse::statement_list()
3434 while (this->statement_may_start_here())
3436 this->statement(NULL);
3437 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3438 this->advance_token();
3439 else if (this->peek_token()->is_op(OPERATOR_RCURLY))
3443 if (!this->peek_token()->is_eof() || !saw_errors())
3444 error_at(this->location(), "expected %<;%> or %<}%> or newline");
3445 if (!this->skip_past_error(OPERATOR_RCURLY))
3452 Parse::statement_list_may_start_here()
3454 return this->statement_may_start_here();
3457 // ExpressionStat = Expression .
3460 Parse::expression_stat(Expression* exp)
3462 exp->discarding_value();
3463 this->gogo_->add_statement(Statement::make_statement(exp));
3466 // SendStmt = Channel "<-" Expression .
3467 // Channel = Expression .
3470 Parse::send_stmt(Expression* channel)
3472 go_assert(this->peek_token()->is_op(OPERATOR_CHANOP));
3473 source_location loc = this->location();
3474 this->advance_token();
3475 Expression* val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
3476 Statement* s = Statement::make_send_statement(channel, val, loc);
3477 this->gogo_->add_statement(s);
3480 // IncDecStat = Expression ( "++" | "--" ) .
3483 Parse::inc_dec_stat(Expression* exp)
3485 const Token* token = this->peek_token();
3487 // Lvalue maps require special handling.
3488 if (exp->index_expression() != NULL)
3489 exp->index_expression()->set_is_lvalue();
3491 if (token->is_op(OPERATOR_PLUSPLUS))
3492 this->gogo_->add_statement(Statement::make_inc_statement(exp));
3493 else if (token->is_op(OPERATOR_MINUSMINUS))
3494 this->gogo_->add_statement(Statement::make_dec_statement(exp));
3497 this->advance_token();
3500 // Assignment = ExpressionList assign_op ExpressionList .
3502 // EXP is an expression that we have already parsed.
3504 // If RANGE_CLAUSE is not NULL, then this will recognize a
3508 Parse::assignment(Expression* expr, Range_clause* p_range_clause)
3510 Expression_list* vars;
3511 if (!this->peek_token()->is_op(OPERATOR_COMMA))
3513 vars = new Expression_list();
3514 vars->push_back(expr);
3518 this->advance_token();
3519 vars = this->expression_list(expr, true);
3522 this->tuple_assignment(vars, p_range_clause);
3525 // An assignment statement. LHS is the list of expressions which
3526 // appear on the left hand side.
3528 // If RANGE_CLAUSE is not NULL, then this will recognize a
3532 Parse::tuple_assignment(Expression_list* lhs, Range_clause* p_range_clause)
3534 const Token* token = this->peek_token();
3535 if (!token->is_op(OPERATOR_EQ)
3536 && !token->is_op(OPERATOR_PLUSEQ)
3537 && !token->is_op(OPERATOR_MINUSEQ)
3538 && !token->is_op(OPERATOR_OREQ)
3539 && !token->is_op(OPERATOR_XOREQ)
3540 && !token->is_op(OPERATOR_MULTEQ)
3541 && !token->is_op(OPERATOR_DIVEQ)
3542 && !token->is_op(OPERATOR_MODEQ)
3543 && !token->is_op(OPERATOR_LSHIFTEQ)
3544 && !token->is_op(OPERATOR_RSHIFTEQ)
3545 && !token->is_op(OPERATOR_ANDEQ)
3546 && !token->is_op(OPERATOR_BITCLEAREQ))
3548 error_at(this->location(), "expected assignment operator");
3551 Operator op = token->op();
3552 source_location location = token->location();
3554 token = this->advance_token();
3556 if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
3558 if (op != OPERATOR_EQ)
3559 error_at(this->location(), "range clause requires %<=%>");
3560 this->range_clause_expr(lhs, p_range_clause);
3564 Expression_list* vals = this->expression_list(NULL, false);
3566 // We've parsed everything; check for errors.
3567 if (lhs == NULL || vals == NULL)
3569 for (Expression_list::const_iterator pe = lhs->begin();
3573 if ((*pe)->is_error_expression())
3575 if (op != OPERATOR_EQ && (*pe)->is_sink_expression())
3576 error_at((*pe)->location(), "cannot use _ as value");
3578 for (Expression_list::const_iterator pe = vals->begin();
3582 if ((*pe)->is_error_expression())
3586 // Map expressions act differently when they are lvalues.
3587 for (Expression_list::iterator plv = lhs->begin();
3590 if ((*plv)->index_expression() != NULL)
3591 (*plv)->index_expression()->set_is_lvalue();
3593 Call_expression* call;
3594 Index_expression* map_index;
3595 Receive_expression* receive;
3596 Type_guard_expression* type_guard;
3597 if (lhs->size() == vals->size())
3600 if (lhs->size() > 1)
3602 if (op != OPERATOR_EQ)
3603 error_at(location, "multiple values only permitted with %<=%>");
3604 s = Statement::make_tuple_assignment(lhs, vals, location);
3608 if (op == OPERATOR_EQ)
3609 s = Statement::make_assignment(lhs->front(), vals->front(),
3612 s = Statement::make_assignment_operation(op, lhs->front(),
3613 vals->front(), location);
3617 this->gogo_->add_statement(s);
3619 else if (vals->size() == 1
3620 && (call = (*vals->begin())->call_expression()) != NULL)
3622 if (op != OPERATOR_EQ)
3623 error_at(location, "multiple results only permitted with %<=%>");
3625 vals = new Expression_list;
3626 for (unsigned int i = 0; i < lhs->size(); ++i)
3627 vals->push_back(Expression::make_call_result(call, i));
3628 Statement* s = Statement::make_tuple_assignment(lhs, vals, location);
3629 this->gogo_->add_statement(s);
3631 else if (lhs->size() == 2
3632 && vals->size() == 1
3633 && (map_index = (*vals->begin())->index_expression()) != NULL)
3635 if (op != OPERATOR_EQ)
3636 error_at(location, "two values from map requires %<=%>");
3637 Expression* val = lhs->front();
3638 Expression* present = lhs->back();
3639 Statement* s = Statement::make_tuple_map_assignment(val, present,
3640 map_index, location);
3641 this->gogo_->add_statement(s);
3643 else if (lhs->size() == 1
3644 && vals->size() == 2
3645 && (map_index = lhs->front()->index_expression()) != NULL)
3647 if (op != OPERATOR_EQ)
3648 error_at(location, "assigning tuple to map index requires %<=%>");
3649 Expression* val = vals->front();
3650 Expression* should_set = vals->back();
3651 Statement* s = Statement::make_map_assignment(map_index, val, should_set,
3653 this->gogo_->add_statement(s);
3655 else if (lhs->size() == 2
3656 && vals->size() == 1
3657 && (receive = (*vals->begin())->receive_expression()) != NULL)
3659 if (op != OPERATOR_EQ)
3660 error_at(location, "two values from receive requires %<=%>");
3661 Expression* val = lhs->front();
3662 Expression* success = lhs->back();
3663 Expression* channel = receive->channel();
3664 Statement* s = Statement::make_tuple_receive_assignment(val, success,
3668 this->gogo_->add_statement(s);
3670 else if (lhs->size() == 2
3671 && vals->size() == 1
3672 && (type_guard = (*vals->begin())->type_guard_expression()) != NULL)
3674 if (op != OPERATOR_EQ)
3675 error_at(location, "two values from type guard requires %<=%>");
3676 Expression* val = lhs->front();
3677 Expression* ok = lhs->back();
3678 Expression* expr = type_guard->expr();
3679 Type* type = type_guard->type();
3680 Statement* s = Statement::make_tuple_type_guard_assignment(val, ok,
3683 this->gogo_->add_statement(s);
3687 error_at(location, "number of variables does not match number of values");
3691 // GoStat = "go" Expression .
3692 // DeferStat = "defer" Expression .
3695 Parse::go_or_defer_stat()
3697 go_assert(this->peek_token()->is_keyword(KEYWORD_GO)
3698 || this->peek_token()->is_keyword(KEYWORD_DEFER));
3699 bool is_go = this->peek_token()->is_keyword(KEYWORD_GO);
3700 source_location stat_location = this->location();
3701 this->advance_token();
3702 source_location expr_location = this->location();
3703 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
3704 Call_expression* call_expr = expr->call_expression();
3705 if (call_expr == NULL)
3707 error_at(expr_location, "expected call expression");
3711 // Make it easier to simplify go/defer statements by putting every
3712 // statement in its own block.
3713 this->gogo_->start_block(stat_location);
3716 stat = Statement::make_go_statement(call_expr, stat_location);
3718 stat = Statement::make_defer_statement(call_expr, stat_location);
3719 this->gogo_->add_statement(stat);
3720 this->gogo_->add_block(this->gogo_->finish_block(stat_location),
3724 // ReturnStat = "return" [ ExpressionList ] .
3727 Parse::return_stat()
3729 go_assert(this->peek_token()->is_keyword(KEYWORD_RETURN));
3730 source_location location = this->location();
3731 this->advance_token();
3732 Expression_list* vals = NULL;
3733 if (this->expression_may_start_here())
3734 vals = this->expression_list(NULL, false);
3735 this->gogo_->add_statement(Statement::make_return_statement(vals, location));
3738 // IfStmt = "if" [ SimpleStmt ";" ] Expression Block [ "else" Statement ] .
3743 go_assert(this->peek_token()->is_keyword(KEYWORD_IF));
3744 source_location location = this->location();
3745 this->advance_token();
3747 this->gogo_->start_block(location);
3749 bool saw_simple_stat = false;
3750 Expression* cond = NULL;
3752 if (this->simple_stat_may_start_here())
3754 cond = this->simple_stat(false, &saw_send_stmt, NULL, NULL);
3755 saw_simple_stat = true;
3757 if (cond != NULL && this->peek_token()->is_op(OPERATOR_SEMICOLON))
3759 // The SimpleStat is an expression statement.
3760 this->expression_stat(cond);
3765 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3766 this->advance_token();
3767 else if (saw_simple_stat)
3770 error_at(this->location(),
3771 ("send statement used as value; "
3772 "use select for non-blocking send"));
3774 error_at(this->location(),
3775 "expected %<;%> after statement in if expression");
3776 if (!this->expression_may_start_here())
3777 cond = Expression::make_error(this->location());
3779 if (cond == NULL && this->peek_token()->is_op(OPERATOR_LCURLY))
3781 error_at(this->location(),
3782 "missing condition in if statement");
3783 cond = Expression::make_error(this->location());
3786 cond = this->expression(PRECEDENCE_NORMAL, false, false, NULL);
3789 this->gogo_->start_block(this->location());
3790 source_location end_loc = this->block();
3791 Block* then_block = this->gogo_->finish_block(end_loc);
3793 // Check for the easy error of a newline before "else".
3794 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3796 source_location semi_loc = this->location();
3797 if (this->advance_token()->is_keyword(KEYWORD_ELSE))
3798 error_at(this->location(),
3799 "unexpected semicolon or newline before %<else%>");
3801 this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
3805 Block* else_block = NULL;
3806 if (this->peek_token()->is_keyword(KEYWORD_ELSE))
3808 this->advance_token();
3809 // We create a block to gather the statement.
3810 this->gogo_->start_block(this->location());
3811 this->statement(NULL);
3812 else_block = this->gogo_->finish_block(this->location());
3815 this->gogo_->add_statement(Statement::make_if_statement(cond, then_block,
3819 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3823 // SwitchStmt = ExprSwitchStmt | TypeSwitchStmt .
3824 // ExprSwitchStmt = "switch" [ [ SimpleStat ] ";" ] [ Expression ]
3825 // "{" { ExprCaseClause } "}" .
3826 // TypeSwitchStmt = "switch" [ [ SimpleStat ] ";" ] TypeSwitchGuard
3827 // "{" { TypeCaseClause } "}" .
3828 // TypeSwitchGuard = [ identifier ":=" ] Expression "." "(" "type" ")" .
3831 Parse::switch_stat(Label* label)
3833 go_assert(this->peek_token()->is_keyword(KEYWORD_SWITCH));
3834 source_location location = this->location();
3835 this->advance_token();
3837 this->gogo_->start_block(location);
3839 bool saw_simple_stat = false;
3840 Expression* switch_val = NULL;
3842 Type_switch type_switch;
3843 if (this->simple_stat_may_start_here())
3845 switch_val = this->simple_stat(false, &saw_send_stmt, NULL,
3847 saw_simple_stat = true;
3849 if (switch_val != NULL && this->peek_token()->is_op(OPERATOR_SEMICOLON))
3851 // The SimpleStat is an expression statement.
3852 this->expression_stat(switch_val);
3855 if (switch_val == NULL && !type_switch.found)
3857 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3858 this->advance_token();
3859 else if (saw_simple_stat)
3862 error_at(this->location(),
3863 ("send statement used as value; "
3864 "use select for non-blocking send"));
3866 error_at(this->location(),
3867 "expected %<;%> after statement in switch expression");
3869 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3871 if (this->peek_token()->is_identifier())
3873 const Token* token = this->peek_token();
3874 std::string identifier = token->identifier();
3875 bool is_exported = token->is_identifier_exported();
3876 source_location id_loc = token->location();
3878 token = this->advance_token();
3879 bool is_coloneq = token->is_op(OPERATOR_COLONEQ);
3880 this->unget_token(Token::make_identifier_token(identifier,
3885 // This must be a TypeSwitchGuard.
3886 switch_val = this->simple_stat(false, &saw_send_stmt, NULL,
3888 if (!type_switch.found)
3890 if (switch_val == NULL
3891 || !switch_val->is_error_expression())
3893 error_at(id_loc, "expected type switch assignment");
3894 switch_val = Expression::make_error(id_loc);
3899 if (switch_val == NULL && !type_switch.found)
3901 switch_val = this->expression(PRECEDENCE_NORMAL, false, false,
3902 &type_switch.found);
3903 if (type_switch.found)
3905 type_switch.name.clear();
3906 type_switch.expr = switch_val;
3907 type_switch.location = switch_val->location();
3913 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3915 source_location token_loc = this->location();
3916 if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
3917 && this->advance_token()->is_op(OPERATOR_LCURLY))
3918 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
3919 else if (this->peek_token()->is_op(OPERATOR_COLONEQ))
3921 error_at(token_loc, "invalid variable name");
3922 this->advance_token();
3923 this->expression(PRECEDENCE_NORMAL, false, false,
3924 &type_switch.found);
3925 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
3926 this->advance_token();
3927 if (!this->peek_token()->is_op(OPERATOR_LCURLY))
3929 if (type_switch.found)
3930 type_switch.expr = Expression::make_error(location);
3934 error_at(this->location(), "expected %<{%>");
3935 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3940 this->advance_token();
3942 Statement* statement;
3943 if (type_switch.found)
3944 statement = this->type_switch_body(label, type_switch, location);
3946 statement = this->expr_switch_body(label, switch_val, location);
3948 if (statement != NULL)
3949 this->gogo_->add_statement(statement);
3951 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
3955 // The body of an expression switch.
3956 // "{" { ExprCaseClause } "}"
3959 Parse::expr_switch_body(Label* label, Expression* switch_val,
3960 source_location location)
3962 Switch_statement* statement = Statement::make_switch_statement(switch_val,
3965 this->push_break_statement(statement, label);
3967 Case_clauses* case_clauses = new Case_clauses();
3968 bool saw_default = false;
3969 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
3971 if (this->peek_token()->is_eof())
3974 error_at(this->location(), "missing %<}%>");
3977 this->expr_case_clause(case_clauses, &saw_default);
3979 this->advance_token();
3981 statement->add_clauses(case_clauses);
3983 this->pop_break_statement();
3988 // ExprCaseClause = ExprSwitchCase ":" [ StatementList ] .
3989 // FallthroughStat = "fallthrough" .
3992 Parse::expr_case_clause(Case_clauses* clauses, bool* saw_default)
3994 source_location location = this->location();
3996 bool is_default = false;
3997 Expression_list* vals = this->expr_switch_case(&is_default);
3999 if (!this->peek_token()->is_op(OPERATOR_COLON))
4002 error_at(this->location(), "expected %<:%>");
4006 this->advance_token();
4008 Block* statements = NULL;
4009 if (this->statement_list_may_start_here())
4011 this->gogo_->start_block(this->location());
4012 this->statement_list();
4013 statements = this->gogo_->finish_block(this->location());
4016 bool is_fallthrough = false;
4017 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH))
4019 is_fallthrough = true;
4020 if (this->advance_token()->is_op(OPERATOR_SEMICOLON))
4021 this->advance_token();
4028 error_at(location, "multiple defaults in switch");
4031 *saw_default = true;
4034 if (is_default || vals != NULL)
4035 clauses->add(vals, is_default, statements, is_fallthrough, location);
4038 // ExprSwitchCase = "case" ExpressionList | "default" .
4041 Parse::expr_switch_case(bool* is_default)
4043 const Token* token = this->peek_token();
4044 if (token->is_keyword(KEYWORD_CASE))
4046 this->advance_token();
4047 return this->expression_list(NULL, false);
4049 else if (token->is_keyword(KEYWORD_DEFAULT))
4051 this->advance_token();
4058 error_at(this->location(), "expected %<case%> or %<default%>");
4059 if (!token->is_op(OPERATOR_RCURLY))
4060 this->advance_token();
4065 // The body of a type switch.
4066 // "{" { TypeCaseClause } "}" .
4069 Parse::type_switch_body(Label* label, const Type_switch& type_switch,
4070 source_location location)
4072 Named_object* switch_no = NULL;
4073 if (!type_switch.name.empty())
4075 Variable* switch_var = new Variable(NULL, type_switch.expr, false, false,
4076 false, type_switch.location);
4077 switch_no = this->gogo_->add_variable(type_switch.name, switch_var);
4080 Type_switch_statement* statement =
4081 Statement::make_type_switch_statement(switch_no,
4087 this->push_break_statement(statement, label);
4089 Type_case_clauses* case_clauses = new Type_case_clauses();
4090 bool saw_default = false;
4091 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
4093 if (this->peek_token()->is_eof())
4095 error_at(this->location(), "missing %<}%>");
4098 this->type_case_clause(switch_no, case_clauses, &saw_default);
4100 this->advance_token();
4102 statement->add_clauses(case_clauses);
4104 this->pop_break_statement();
4109 // TypeCaseClause = TypeSwitchCase ":" [ StatementList ] .
4112 Parse::type_case_clause(Named_object* switch_no, Type_case_clauses* clauses,
4115 source_location location = this->location();
4117 std::vector<Type*> types;
4118 bool is_default = false;
4119 this->type_switch_case(&types, &is_default);
4121 if (!this->peek_token()->is_op(OPERATOR_COLON))
4122 error_at(this->location(), "expected %<:%>");
4124 this->advance_token();
4126 Block* statements = NULL;
4127 if (this->statement_list_may_start_here())
4129 this->gogo_->start_block(this->location());
4130 if (switch_no != NULL && types.size() == 1)
4132 Type* type = types.front();
4133 Expression* init = Expression::make_var_reference(switch_no,
4135 init = Expression::make_type_guard(init, type, location);
4136 Variable* v = new Variable(type, init, false, false, false,
4138 v->set_is_type_switch_var();
4139 this->gogo_->add_variable(switch_no->name(), v);
4141 this->statement_list();
4142 statements = this->gogo_->finish_block(this->location());
4145 if (this->peek_token()->is_keyword(KEYWORD_FALLTHROUGH))
4147 error_at(this->location(),
4148 "fallthrough is not permitted in a type switch");
4149 if (this->advance_token()->is_op(OPERATOR_SEMICOLON))
4150 this->advance_token();
4155 go_assert(types.empty());
4158 error_at(location, "multiple defaults in type switch");
4161 *saw_default = true;
4162 clauses->add(NULL, false, true, statements, location);
4164 else if (!types.empty())
4166 for (std::vector<Type*>::const_iterator p = types.begin();
4167 p + 1 != types.end();
4169 clauses->add(*p, true, false, NULL, location);
4170 clauses->add(types.back(), false, false, statements, location);
4173 clauses->add(Type::make_error_type(), false, false, statements, location);
4176 // TypeSwitchCase = "case" type | "default"
4178 // We accept a comma separated list of types.
4181 Parse::type_switch_case(std::vector<Type*>* types, bool* is_default)
4183 const Token* token = this->peek_token();
4184 if (token->is_keyword(KEYWORD_CASE))
4186 this->advance_token();
4189 Type* t = this->type();
4190 if (!t->is_error_type())
4191 types->push_back(t);
4192 if (!this->peek_token()->is_op(OPERATOR_COMMA))
4194 this->advance_token();
4197 else if (token->is_keyword(KEYWORD_DEFAULT))
4199 this->advance_token();
4204 error_at(this->location(), "expected %<case%> or %<default%>");
4205 if (!token->is_op(OPERATOR_RCURLY))
4206 this->advance_token();
4210 // SelectStat = "select" "{" { CommClause } "}" .
4213 Parse::select_stat(Label* label)
4215 go_assert(this->peek_token()->is_keyword(KEYWORD_SELECT));
4216 source_location location = this->location();
4217 const Token* token = this->advance_token();
4219 if (!token->is_op(OPERATOR_LCURLY))
4221 source_location token_loc = token->location();
4222 if (token->is_op(OPERATOR_SEMICOLON)
4223 && this->advance_token()->is_op(OPERATOR_LCURLY))
4224 error_at(token_loc, "unexpected semicolon or newline before %<{%>");
4227 error_at(this->location(), "expected %<{%>");
4231 this->advance_token();
4233 Select_statement* statement = Statement::make_select_statement(location);
4235 this->push_break_statement(statement, label);
4237 Select_clauses* select_clauses = new Select_clauses();
4238 bool saw_default = false;
4239 while (!this->peek_token()->is_op(OPERATOR_RCURLY))
4241 if (this->peek_token()->is_eof())
4243 error_at(this->location(), "expected %<}%>");
4246 this->comm_clause(select_clauses, &saw_default);
4249 this->advance_token();
4251 statement->add_clauses(select_clauses);
4253 this->pop_break_statement();
4255 this->gogo_->add_statement(statement);
4258 // CommClause = CommCase ":" { Statement ";" } .
4261 Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
4263 source_location location = this->location();
4264 bool is_send = false;
4265 Expression* channel = NULL;
4266 Expression* val = NULL;
4267 Expression* closed = NULL;
4268 std::string varname;
4269 std::string closedname;
4270 bool is_default = false;
4271 bool got_case = this->comm_case(&is_send, &channel, &val, &closed,
4272 &varname, &closedname, &is_default);
4276 && closedname.empty()
4278 && val->index_expression() != NULL)
4279 val->index_expression()->set_is_lvalue();
4281 if (this->peek_token()->is_op(OPERATOR_COLON))
4282 this->advance_token();
4284 error_at(this->location(), "expected colon");
4286 this->gogo_->start_block(this->location());
4288 Named_object* var = NULL;
4289 if (!varname.empty())
4291 // FIXME: LOCATION is slightly wrong here.
4292 Variable* v = new Variable(NULL, channel, false, false, false,
4294 v->set_type_from_chan_element();
4295 var = this->gogo_->add_variable(varname, v);
4298 Named_object* closedvar = NULL;
4299 if (!closedname.empty())
4301 // FIXME: LOCATION is slightly wrong here.
4302 Variable* v = new Variable(Type::lookup_bool_type(), NULL,
4303 false, false, false, location);
4304 closedvar = this->gogo_->add_variable(closedname, v);
4307 this->statement_list();
4309 Block* statements = this->gogo_->finish_block(this->location());
4315 error_at(location, "multiple defaults in select");
4318 *saw_default = true;
4322 clauses->add(is_send, channel, val, closed, var, closedvar, is_default,
4323 statements, location);
4324 else if (statements != NULL)
4326 // Add the statements to make sure that any names they define
4328 this->gogo_->add_block(statements, location);
4332 // CommCase = "case" ( SendStmt | RecvStmt ) | "default" .
4335 Parse::comm_case(bool* is_send, Expression** channel, Expression** val,
4336 Expression** closed, std::string* varname,
4337 std::string* closedname, bool* is_default)
4339 const Token* token = this->peek_token();
4340 if (token->is_keyword(KEYWORD_DEFAULT))
4342 this->advance_token();
4345 else if (token->is_keyword(KEYWORD_CASE))
4347 this->advance_token();
4348 if (!this->send_or_recv_stmt(is_send, channel, val, closed, varname,
4354 error_at(this->location(), "expected %<case%> or %<default%>");
4355 if (!token->is_op(OPERATOR_RCURLY))
4356 this->advance_token();
4363 // RecvStmt = [ Expression [ "," Expression ] ( "=" | ":=" ) ] RecvExpr .
4364 // RecvExpr = Expression .
4367 Parse::send_or_recv_stmt(bool* is_send, Expression** channel, Expression** val,
4368 Expression** closed, std::string* varname,
4369 std::string* closedname)
4371 const Token* token = this->peek_token();
4372 bool saw_comma = false;
4373 bool closed_is_id = false;
4374 if (token->is_identifier())
4376 Gogo* gogo = this->gogo_;
4377 std::string recv_var = token->identifier();
4378 bool is_rv_exported = token->is_identifier_exported();
4379 source_location recv_var_loc = token->location();
4380 token = this->advance_token();
4381 if (token->is_op(OPERATOR_COLONEQ))
4384 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4386 error_at(this->location(), "expected %<<-%>");
4389 if (recv_var == "_")
4391 error_at(recv_var_loc,
4392 "no new variables on left side of %<:=%>");
4396 *varname = gogo->pack_hidden_name(recv_var, is_rv_exported);
4397 this->advance_token();
4398 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4401 else if (token->is_op(OPERATOR_COMMA))
4403 token = this->advance_token();
4404 if (token->is_identifier())
4406 std::string recv_closed = token->identifier();
4407 bool is_rc_exported = token->is_identifier_exported();
4408 source_location recv_closed_loc = token->location();
4409 closed_is_id = true;
4411 token = this->advance_token();
4412 if (token->is_op(OPERATOR_COLONEQ))
4414 // case rv, rc := <-c:
4415 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4417 error_at(this->location(), "expected %<<-%>");
4420 if (recv_var == "_" && recv_closed == "_")
4422 error_at(recv_var_loc,
4423 "no new variables on left side of %<:=%>");
4427 if (recv_var != "_")
4428 *varname = gogo->pack_hidden_name(recv_var,
4430 if (recv_closed != "_")
4431 *closedname = gogo->pack_hidden_name(recv_closed,
4433 this->advance_token();
4434 *channel = this->expression(PRECEDENCE_NORMAL, false, true,
4439 this->unget_token(Token::make_identifier_token(recv_closed,
4444 *val = this->id_to_expression(gogo->pack_hidden_name(recv_var,
4450 this->unget_token(Token::make_identifier_token(recv_var,
4455 // If SAW_COMMA is false, then we are looking at the start of the
4456 // send or receive expression. If SAW_COMMA is true, then *VAL is
4457 // set and we just read a comma.
4460 if (saw_comma || !this->peek_token()->is_op(OPERATOR_CHANOP))
4461 e = this->expression(PRECEDENCE_NORMAL, true, true, NULL);
4466 this->advance_token();
4467 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4469 // The next token should be ':'. If it is '<-', then we have
4471 // which is to say, send on a channel received from a channel.
4472 if (!this->peek_token()->is_op(OPERATOR_CHANOP))
4475 e = Expression::make_receive(*channel, (*channel)->location());
4478 if (this->peek_token()->is_op(OPERATOR_EQ))
4480 if (!this->advance_token()->is_op(OPERATOR_CHANOP))
4482 error_at(this->location(), "missing %<<-%>");
4486 this->advance_token();
4487 *channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4491 // *VAL is already set.
4492 if (!e->is_sink_expression())
4498 if (!e->is_sink_expression())
4507 error_at(this->location(), "expected %<=%> or %<:=%>");
4509 error_at(this->location(), "expected %<=%>");
4513 if (this->peek_token()->is_op(OPERATOR_CHANOP))
4517 *channel = this->verify_not_sink(e);
4518 this->advance_token();
4519 *val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4523 error_at(this->location(), "expected %<<-%> or %<=%>");
4527 // ForStat = "for" [ Condition | ForClause | RangeClause ] Block .
4528 // Condition = Expression .
4531 Parse::for_stat(Label* label)
4533 go_assert(this->peek_token()->is_keyword(KEYWORD_FOR));
4534 source_location location = this->location();
4535 const Token* token = this->advance_token();
4537 // Open a block to hold any variables defined in the init statement
4538 // of the for statement.
4539 this->gogo_->start_block(location);
4542 Expression* cond = NULL;
4544 Range_clause range_clause;
4546 if (!token->is_op(OPERATOR_LCURLY))
4548 if (token->is_keyword(KEYWORD_VAR))
4550 error_at(this->location(),
4551 "var declaration not allowed in for initializer");
4555 if (token->is_op(OPERATOR_SEMICOLON))
4556 this->for_clause(&cond, &post);
4559 // We might be looking at a Condition, an InitStat, or a
4562 cond = this->simple_stat(false, &saw_send_stmt, &range_clause, NULL);
4563 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
4565 if (cond == NULL && !range_clause.found)
4568 error_at(this->location(),
4569 ("send statement used as value; "
4570 "use select for non-blocking send"));
4572 error_at(this->location(), "parse error in for statement");
4577 if (range_clause.found)
4578 error_at(this->location(), "parse error after range clause");
4582 // COND is actually an expression statement for
4583 // InitStat at the start of a ForClause.
4584 this->expression_stat(cond);
4588 this->for_clause(&cond, &post);
4593 // Build the For_statement and note that it is the current target
4594 // for break and continue statements.
4596 For_statement* sfor;
4597 For_range_statement* srange;
4599 if (!range_clause.found)
4601 sfor = Statement::make_for_statement(init, cond, post, location);
4607 srange = Statement::make_for_range_statement(range_clause.index,
4615 this->push_break_statement(s, label);
4616 this->push_continue_statement(s, label);
4618 // Gather the block of statements in the loop and add them to the
4621 this->gogo_->start_block(this->location());
4622 source_location end_loc = this->block();
4623 Block* statements = this->gogo_->finish_block(end_loc);
4626 sfor->add_statements(statements);
4628 srange->add_statements(statements);
4630 // This is no longer the break/continue target.
4631 this->pop_break_statement();
4632 this->pop_continue_statement();
4634 // Add the For_statement to the list of statements, and close out
4635 // the block we started to hold any variables defined in the for
4638 this->gogo_->add_statement(s);
4640 this->gogo_->add_block(this->gogo_->finish_block(this->location()),
4644 // ForClause = [ InitStat ] ";" [ Condition ] ";" [ PostStat ] .
4645 // InitStat = SimpleStat .
4646 // PostStat = SimpleStat .
4648 // We have already read InitStat at this point.
4651 Parse::for_clause(Expression** cond, Block** post)
4653 go_assert(this->peek_token()->is_op(OPERATOR_SEMICOLON));
4654 this->advance_token();
4655 if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
4657 else if (this->peek_token()->is_op(OPERATOR_LCURLY))
4659 error_at(this->location(),
4660 "unexpected semicolon or newline before %<{%>");
4666 *cond = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
4667 if (!this->peek_token()->is_op(OPERATOR_SEMICOLON))
4668 error_at(this->location(), "expected semicolon");
4670 this->advance_token();
4672 if (this->peek_token()->is_op(OPERATOR_LCURLY))
4676 this->gogo_->start_block(this->location());
4677 this->simple_stat(false, NULL, NULL, NULL);
4678 *post = this->gogo_->finish_block(this->location());
4682 // RangeClause = IdentifierList ( "=" | ":=" ) "range" Expression .
4684 // This is the := version. It is called with a list of identifiers.
4687 Parse::range_clause_decl(const Typed_identifier_list* til,
4688 Range_clause* p_range_clause)
4690 go_assert(this->peek_token()->is_keyword(KEYWORD_RANGE));
4691 source_location location = this->location();
4693 p_range_clause->found = true;
4695 go_assert(til->size() >= 1);
4696 if (til->size() > 2)
4697 error_at(this->location(), "too many variables for range clause");
4699 this->advance_token();
4700 Expression* expr = this->expression(PRECEDENCE_NORMAL, false, false, NULL);
4701 p_range_clause->range = expr;
4703 bool any_new = false;
4705 const Typed_identifier* pti = &til->front();
4706 Named_object* no = this->init_var(*pti, NULL, expr, true, true, &any_new);
4707 if (any_new && no->is_variable())
4708 no->var_value()->set_type_from_range_index();
4709 p_range_clause->index = Expression::make_var_reference(no, location);
4711 if (til->size() == 1)
4712 p_range_clause->value = NULL;
4716 bool is_new = false;
4717 no = this->init_var(*pti, NULL, expr, true, true, &is_new);
4718 if (is_new && no->is_variable())
4719 no->var_value()->set_type_from_range_value();
4722 p_range_clause->value = Expression::make_var_reference(no, location);
4726 error_at(location, "variables redeclared but no variable is new");
4729 // The = version of RangeClause. This is called with a list of
4733 Parse::range_clause_expr(const Expression_list* vals,
4734 Range_clause* p_range_clause)
4736 go_assert(this->peek_token()->is_keyword(KEYWORD_RANGE));
4738 p_range_clause->found = true;
4740 go_assert(vals->size() >= 1);
4741 if (vals->size() > 2)
4742 error_at(this->location(), "too many variables for range clause");
4744 this->advance_token();
4745 p_range_clause->range = this->expression(PRECEDENCE_NORMAL, false, false,
4748 p_range_clause->index = vals->front();
4749 if (vals->size() == 1)
4750 p_range_clause->value = NULL;
4752 p_range_clause->value = vals->back();
4755 // Push a statement on the break stack.
4758 Parse::push_break_statement(Statement* enclosing, Label* label)
4760 if (this->break_stack_ == NULL)
4761 this->break_stack_ = new Bc_stack();
4762 this->break_stack_->push_back(std::make_pair(enclosing, label));
4765 // Push a statement on the continue stack.
4768 Parse::push_continue_statement(Statement* enclosing, Label* label)
4770 if (this->continue_stack_ == NULL)
4771 this->continue_stack_ = new Bc_stack();
4772 this->continue_stack_->push_back(std::make_pair(enclosing, label));
4775 // Pop the break stack.
4778 Parse::pop_break_statement()
4780 this->break_stack_->pop_back();
4783 // Pop the continue stack.
4786 Parse::pop_continue_statement()
4788 this->continue_stack_->pop_back();
4791 // Find a break or continue statement given a label name.
4794 Parse::find_bc_statement(const Bc_stack* bc_stack, const std::string& label)
4796 if (bc_stack == NULL)
4798 for (Bc_stack::const_reverse_iterator p = bc_stack->rbegin();
4799 p != bc_stack->rend();
4802 if (p->second != NULL && p->second->name() == label)
4804 p->second->set_is_used();
4811 // BreakStat = "break" [ identifier ] .
4816 go_assert(this->peek_token()->is_keyword(KEYWORD_BREAK));
4817 source_location location = this->location();
4819 const Token* token = this->advance_token();
4820 Statement* enclosing;
4821 if (!token->is_identifier())
4823 if (this->break_stack_ == NULL || this->break_stack_->empty())
4825 error_at(this->location(),
4826 "break statement not within for or switch or select");
4829 enclosing = this->break_stack_->back().first;
4833 enclosing = this->find_bc_statement(this->break_stack_,
4834 token->identifier());
4835 if (enclosing == NULL)
4837 // If there is a label with this name, mark it as used to
4838 // avoid a useless error about an unused label.
4839 this->gogo_->add_label_reference(token->identifier());
4841 error_at(token->location(), "invalid break label %qs",
4842 Gogo::message_name(token->identifier()).c_str());
4843 this->advance_token();
4846 this->advance_token();
4849 Unnamed_label* label;
4850 if (enclosing->classification() == Statement::STATEMENT_FOR)
4851 label = enclosing->for_statement()->break_label();
4852 else if (enclosing->classification() == Statement::STATEMENT_FOR_RANGE)
4853 label = enclosing->for_range_statement()->break_label();
4854 else if (enclosing->classification() == Statement::STATEMENT_SWITCH)
4855 label = enclosing->switch_statement()->break_label();
4856 else if (enclosing->classification() == Statement::STATEMENT_TYPE_SWITCH)
4857 label = enclosing->type_switch_statement()->break_label();
4858 else if (enclosing->classification() == Statement::STATEMENT_SELECT)
4859 label = enclosing->select_statement()->break_label();
4863 this->gogo_->add_statement(Statement::make_break_statement(label,
4867 // ContinueStat = "continue" [ identifier ] .
4870 Parse::continue_stat()
4872 go_assert(this->peek_token()->is_keyword(KEYWORD_CONTINUE));
4873 source_location location = this->location();
4875 const Token* token = this->advance_token();
4876 Statement* enclosing;
4877 if (!token->is_identifier())
4879 if (this->continue_stack_ == NULL || this->continue_stack_->empty())
4881 error_at(this->location(), "continue statement not within for");
4884 enclosing = this->continue_stack_->back().first;
4888 enclosing = this->find_bc_statement(this->continue_stack_,
4889 token->identifier());
4890 if (enclosing == NULL)
4892 // If there is a label with this name, mark it as used to
4893 // avoid a useless error about an unused label.
4894 this->gogo_->add_label_reference(token->identifier());
4896 error_at(token->location(), "invalid continue label %qs",
4897 Gogo::message_name(token->identifier()).c_str());
4898 this->advance_token();
4901 this->advance_token();
4904 Unnamed_label* label;
4905 if (enclosing->classification() == Statement::STATEMENT_FOR)
4906 label = enclosing->for_statement()->continue_label();
4907 else if (enclosing->classification() == Statement::STATEMENT_FOR_RANGE)
4908 label = enclosing->for_range_statement()->continue_label();
4912 this->gogo_->add_statement(Statement::make_continue_statement(label,
4916 // GotoStat = "goto" identifier .
4921 go_assert(this->peek_token()->is_keyword(KEYWORD_GOTO));
4922 source_location location = this->location();
4923 const Token* token = this->advance_token();
4924 if (!token->is_identifier())
4925 error_at(this->location(), "expected label for goto");
4928 Label* label = this->gogo_->add_label_reference(token->identifier());
4929 Statement* s = Statement::make_goto_statement(label, location);
4930 this->gogo_->add_statement(s);
4931 this->advance_token();
4935 // PackageClause = "package" PackageName .
4938 Parse::package_clause()
4940 const Token* token = this->peek_token();
4941 source_location location = token->location();
4943 if (!token->is_keyword(KEYWORD_PACKAGE))
4945 error_at(this->location(), "program must start with package clause");
4950 token = this->advance_token();
4951 if (token->is_identifier())
4953 name = token->identifier();
4956 error_at(this->location(), "invalid package name _");
4959 this->advance_token();
4963 error_at(this->location(), "package name must be an identifier");
4967 this->gogo_->set_package_name(name, location);
4970 // ImportDecl = "import" Decl<ImportSpec> .
4973 Parse::import_decl()
4975 go_assert(this->peek_token()->is_keyword(KEYWORD_IMPORT));
4976 this->advance_token();
4977 this->decl(&Parse::import_spec, NULL);
4980 // ImportSpec = [ "." | PackageName ] PackageFileName .
4983 Parse::import_spec(void*)
4985 const Token* token = this->peek_token();
4986 source_location location = token->location();
4988 std::string local_name;
4989 bool is_local_name_exported = false;
4990 if (token->is_op(OPERATOR_DOT))
4993 token = this->advance_token();
4995 else if (token->is_identifier())
4997 local_name = token->identifier();
4998 is_local_name_exported = token->is_identifier_exported();
4999 token = this->advance_token();
5002 if (!token->is_string())
5004 error_at(this->location(), "missing import package name");
5008 this->gogo_->import_package(token->string_value(), local_name,
5009 is_local_name_exported, location);
5011 this->advance_token();
5014 // SourceFile = PackageClause ";" { ImportDecl ";" }
5015 // { TopLevelDecl ";" } .
5020 this->package_clause();
5022 const Token* token = this->peek_token();
5023 if (token->is_op(OPERATOR_SEMICOLON))
5024 token = this->advance_token();
5026 error_at(this->location(),
5027 "expected %<;%> or newline after package clause");
5029 while (token->is_keyword(KEYWORD_IMPORT))
5031 this->import_decl();
5032 token = this->peek_token();
5033 if (token->is_op(OPERATOR_SEMICOLON))
5034 token = this->advance_token();
5036 error_at(this->location(),
5037 "expected %<;%> or newline after import declaration");
5040 while (!token->is_eof())
5042 if (this->declaration_may_start_here())
5043 this->declaration();
5046 error_at(this->location(), "expected declaration");
5048 this->advance_token();
5049 while (!this->peek_token()->is_eof()
5050 && !this->peek_token()->is_op(OPERATOR_SEMICOLON)
5051 && !this->peek_token()->is_op(OPERATOR_RCURLY));
5052 if (!this->peek_token()->is_eof()
5053 && !this->peek_token()->is_op(OPERATOR_SEMICOLON))
5054 this->advance_token();
5056 token = this->peek_token();
5057 if (token->is_op(OPERATOR_SEMICOLON))
5058 token = this->advance_token();
5059 else if (!token->is_eof() || !saw_errors())
5061 if (token->is_op(OPERATOR_CHANOP))
5062 error_at(this->location(),
5063 ("send statement used as value; "
5064 "use select for non-blocking send"));
5066 error_at(this->location(),
5067 "expected %<;%> or newline after top level declaration");
5068 this->skip_past_error(OPERATOR_INVALID);
5073 // Reset the current iota value.
5081 // Return the current iota value.
5089 // Increment the current iota value.
5092 Parse::increment_iota()
5097 // Skip forward to a semicolon or OP. OP will normally be
5098 // OPERATOR_RPAREN or OPERATOR_RCURLY. If we find a semicolon, move
5099 // past it and return. If we find OP, it will be the next token to
5100 // read. Return true if we are OK, false if we found EOF.
5103 Parse::skip_past_error(Operator op)
5105 const Token* token = this->peek_token();
5106 while (!token->is_op(op))
5108 if (token->is_eof())
5110 if (token->is_op(OPERATOR_SEMICOLON))
5112 this->advance_token();
5115 token = this->advance_token();
5120 // Check that an expression is not a sink.
5123 Parse::verify_not_sink(Expression* expr)
5125 if (expr->is_sink_expression())
5127 error_at(expr->location(), "cannot use _ as value");
5128 expr = Expression::make_error(expr->location());