blob: 6ed4377ddc13cf3ac0c856a48727f26f4cfcb391 [file] [log] [blame]
// parse.cc -- Go frontend parser.
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "go-system.h"
#include "lex.h"
#include "gogo.h"
#include "go-diagnostics.h"
#include "types.h"
#include "statements.h"
#include "expressions.h"
#include "parse.h"
// Struct Parse::Enclosing_var_comparison.
// Return true if v1 should be considered to be less than v2.
bool
Parse::Enclosing_var_comparison::operator()(const Enclosing_var& v1,
const Enclosing_var& v2) const
{
if (v1.var() == v2.var())
return false;
const std::string& n1(v1.var()->name());
const std::string& n2(v2.var()->name());
int i = n1.compare(n2);
if (i < 0)
return true;
else if (i > 0)
return false;
// If we get here it means that a single nested function refers to
// two different variables defined in enclosing functions, and both
// variables have the same name. I think this is impossible.
go_unreachable();
}
// Class Parse.
Parse::Parse(Lex* lex, Gogo* gogo)
: lex_(lex),
token_(Token::make_invalid_token(Linemap::unknown_location())),
unget_token_(Token::make_invalid_token(Linemap::unknown_location())),
unget_token_valid_(false),
is_erroneous_function_(false),
gogo_(gogo),
break_stack_(NULL),
continue_stack_(NULL),
enclosing_vars_()
{
}
// Return the current token.
const Token*
Parse::peek_token()
{
if (this->unget_token_valid_)
return &this->unget_token_;
if (this->token_.is_invalid())
this->token_ = this->lex_->next_token();
return &this->token_;
}
// Advance to the next token and return it.
const Token*
Parse::advance_token()
{
if (this->unget_token_valid_)
{
this->unget_token_valid_ = false;
if (!this->token_.is_invalid())
return &this->token_;
}
this->token_ = this->lex_->next_token();
return &this->token_;
}
// Push a token back on the input stream.
void
Parse::unget_token(const Token& token)
{
go_assert(!this->unget_token_valid_);
this->unget_token_ = token;
this->unget_token_valid_ = true;
}
// The location of the current token.
Location
Parse::location()
{
return this->peek_token()->location();
}
// IdentifierList = identifier { "," identifier } .
void
Parse::identifier_list(Typed_identifier_list* til)
{
const Token* token = this->peek_token();
while (true)
{
if (!token->is_identifier())
{
go_error_at(this->location(), "expected identifier");
return;
}
std::string name =
this->gogo_->pack_hidden_name(token->identifier(),
token->is_identifier_exported());
til->push_back(Typed_identifier(name, NULL, token->location()));
token = this->advance_token();
if (!token->is_op(OPERATOR_COMMA))
return;
token = this->advance_token();
}
}
// ExpressionList = Expression { "," Expression } .
// If MAY_BE_COMPOSITE_LIT is true, an expression may be a composite
// literal.
// If MAY_BE_SINK is true, the expressions in the list may be "_".
Expression_list*
Parse::expression_list(Expression* first, bool may_be_sink,
bool may_be_composite_lit)
{
Expression_list* ret = new Expression_list();
if (first != NULL)
ret->push_back(first);
while (true)
{
ret->push_back(this->expression(PRECEDENCE_NORMAL, may_be_sink,
may_be_composite_lit, NULL, NULL));
const Token* token = this->peek_token();
if (!token->is_op(OPERATOR_COMMA))
return ret;
// Most expression lists permit a trailing comma.
Location location = token->location();
this->advance_token();
if (!this->expression_may_start_here())
{
this->unget_token(Token::make_operator_token(OPERATOR_COMMA,
location));
return ret;
}
}
}
// QualifiedIdent = [ PackageName "." ] identifier .
// PackageName = identifier .
// This sets *PNAME to the identifier and sets *PPACKAGE to the
// package or NULL if there isn't one. This returns true on success,
// false on failure in which case it will have emitted an error
// message.
bool
Parse::qualified_ident(std::string* pname, Named_object** ppackage)
{
const Token* token = this->peek_token();
if (!token->is_identifier())
{
go_error_at(this->location(), "expected identifier");
return false;
}
std::string name = token->identifier();
bool is_exported = token->is_identifier_exported();
name = this->gogo_->pack_hidden_name(name, is_exported);
token = this->advance_token();
if (!token->is_op(OPERATOR_DOT))
{
*pname = name;
*ppackage = NULL;
return true;
}
Named_object* package = this->gogo_->lookup(name, NULL);
if (package == NULL || !package->is_package())
{
go_error_at(this->location(), "expected package");
// We expect . IDENTIFIER; skip both.
if (this->advance_token()->is_identifier())
this->advance_token();
return false;
}
package->package_value()->note_usage(Gogo::unpack_hidden_name(name));
token = this->advance_token();
if (!token->is_identifier())
{
go_error_at(this->location(), "expected identifier");
return false;
}
name = token->identifier();
if (name == "_")
{
go_error_at(this->location(), "invalid use of %<_%>");
name = Gogo::erroneous_name();
}
if (package->name() == this->gogo_->package_name())
name = this->gogo_->pack_hidden_name(name,
token->is_identifier_exported());
*pname = name;
*ppackage = package;
this->advance_token();
return true;
}
// Type = TypeName | TypeLit | "(" Type ")" .
// TypeLit =
// ArrayType | StructType | PointerType | FunctionType | InterfaceType |
// SliceType | MapType | ChannelType .
Type*
Parse::type()
{
const Token* token = this->peek_token();
if (token->is_identifier())
return this->type_name(true);
else if (token->is_op(OPERATOR_LSQUARE))
return this->array_type(false);
else if (token->is_keyword(KEYWORD_CHAN)
|| token->is_op(OPERATOR_CHANOP))
return this->channel_type();
else if (token->is_keyword(KEYWORD_INTERFACE))
return this->interface_type(true);
else if (token->is_keyword(KEYWORD_FUNC))
{
Location location = token->location();
this->advance_token();
Type* type = this->signature(NULL, location);
if (type == NULL)
return Type::make_error_type();
return type;
}
else if (token->is_keyword(KEYWORD_MAP))
return this->map_type();
else if (token->is_keyword(KEYWORD_STRUCT))
return this->struct_type();
else if (token->is_op(OPERATOR_MULT))
return this->pointer_type();
else if (token->is_op(OPERATOR_LPAREN))
{
this->advance_token();
Type* ret = this->type();
if (this->peek_token()->is_op(OPERATOR_RPAREN))
this->advance_token();
else
{
if (!ret->is_error_type())
go_error_at(this->location(), "expected %<)%>");
}
return ret;
}
else
{
go_error_at(token->location(), "expected type");
return Type::make_error_type();
}
}
bool
Parse::type_may_start_here()
{
const Token* token = this->peek_token();
return (token->is_identifier()
|| token->is_op(OPERATOR_LSQUARE)
|| token->is_op(OPERATOR_CHANOP)
|| token->is_keyword(KEYWORD_CHAN)
|| token->is_keyword(KEYWORD_INTERFACE)
|| token->is_keyword(KEYWORD_FUNC)
|| token->is_keyword(KEYWORD_MAP)
|| token->is_keyword(KEYWORD_STRUCT)
|| token->is_op(OPERATOR_MULT)
|| token->is_op(OPERATOR_LPAREN));
}
// TypeName = QualifiedIdent .
// If MAY_BE_NIL is true, then an identifier with the value of the
// predefined constant nil is accepted, returning the nil type.
Type*
Parse::type_name(bool issue_error)
{
Location location = this->location();
std::string name;
Named_object* package;
if (!this->qualified_ident(&name, &package))
return Type::make_error_type();
Named_object* named_object;
if (package == NULL)
named_object = this->gogo_->lookup(name, NULL);
else
{
named_object = package->package_value()->lookup(name);
if (named_object == NULL
&& issue_error
&& package->name() != this->gogo_->package_name())
{
// Check whether the name is there but hidden.
std::string s = ('.' + package->package_value()->pkgpath()
+ '.' + name);
named_object = package->package_value()->lookup(s);
if (named_object != NULL)
{
Package* p = package->package_value();
const std::string& packname(p->package_name());
go_error_at(location,
"invalid reference to hidden type %<%s.%s%>",
Gogo::message_name(packname).c_str(),
Gogo::message_name(name).c_str());
issue_error = false;
}
}
}
bool ok = true;
if (named_object == NULL)
{
if (package == NULL)
named_object = this->gogo_->add_unknown_name(name, location);
else
{
const std::string& packname(package->package_value()->package_name());
go_error_at(location, "reference to undefined identifier %<%s.%s%>",
Gogo::message_name(packname).c_str(),
Gogo::message_name(name).c_str());
issue_error = false;
ok = false;
}
}
else if (named_object->is_type())
{
if (!named_object->type_value()->is_visible())
ok = false;
}
else if (named_object->is_unknown() || named_object->is_type_declaration())
;
else
ok = false;
if (!ok)
{
if (issue_error)
go_error_at(location, "expected type");
return Type::make_error_type();
}
if (named_object->is_type())
return named_object->type_value();
else if (named_object->is_unknown() || named_object->is_type_declaration())
return Type::make_forward_declaration(named_object);
else
go_unreachable();
}
// ArrayType = "[" [ ArrayLength ] "]" ElementType .
// ArrayLength = Expression .
// ElementType = CompleteType .
Type*
Parse::array_type(bool may_use_ellipsis)
{
go_assert(this->peek_token()->is_op(OPERATOR_LSQUARE));
const Token* token = this->advance_token();
Expression* length = NULL;
if (token->is_op(OPERATOR_RSQUARE))
this->advance_token();
else
{
if (!token->is_op(OPERATOR_ELLIPSIS))
length = this->expression(PRECEDENCE_NORMAL, false, true, NULL, NULL);
else if (may_use_ellipsis)
{
// An ellipsis is used in composite literals to represent a
// fixed array of the size of the number of elements. We
// use a length of nil to represent this, and change the
// length when parsing the composite literal.
length = Expression::make_nil(this->location());
this->advance_token();
}
else
{
go_error_at(this->location(),
"use of %<[...]%> outside of array literal");
length = Expression::make_error(this->location());
this->advance_token();
}
if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
{
go_error_at(this->location(), "expected %<]%>");
return Type::make_error_type();
}
this->advance_token();
}
Type* element_type = this->type();
if (element_type->is_error_type())
return Type::make_error_type();
return Type::make_array_type(element_type, length);
}
// MapType = "map" "[" KeyType "]" ValueType .
// KeyType = CompleteType .
// ValueType = CompleteType .
Type*
Parse::map_type()
{
Location location = this->location();
go_assert(this->peek_token()->is_keyword(KEYWORD_MAP));
if (!this->advance_token()->is_op(OPERATOR_LSQUARE))
{
go_error_at(this->location(), "expected %<[%>");
return Type::make_error_type();
}
this->advance_token();
Type* key_type = this->type();
if (!this->peek_token()->is_op(OPERATOR_RSQUARE))
{
go_error_at(this->location(), "expected %<]%>");
return Type::make_error_type();
}
this->advance_token();
Type* value_type = this->type();
if (key_type->is_error_type() || value_type->is_error_type())
return Type::make_error_type();
return Type::make_map_type(key_type, value_type, location);
}
// StructType = "struct" "{" { FieldDecl ";" } "}" .
Type*
Parse::struct_type()
{
go_assert(this->peek_token()->is_keyword(KEYWORD_STRUCT));
Location location = this->location();
if (!this->advance_token()->is_op(OPERATOR_LCURLY))
{
Location token_loc = this->location();
if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
&& this->advance_token()->is_op(OPERATOR_LCURLY))
go_error_at(token_loc, "unexpected semicolon or newline before %<{%>");
else
{
go_error_at(this->location(), "expected %<{%>");
return Type::make_error_type();
}
}
this->advance_token();
Struct_field_list* sfl = new Struct_field_list;
while (!this->peek_token()->is_op(OPERATOR_RCURLY))
{
this->field_decl(sfl);
if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
this->advance_token();
else if (!this->peek_token()->is_op(OPERATOR_RCURLY))
{
go_error_at(this->location(), "expected %<;%> or %<}%> or newline");
if (!this->skip_past_error(OPERATOR_RCURLY))
return Type::make_error_type();
}
}
this->advance_token();
for (Struct_field_list::const_iterator pi = sfl->begin();
pi != sfl->end();
++pi)
{
if (pi->type()->is_error_type())
return pi->type();
for (Struct_field_list::const_iterator pj = pi + 1;
pj != sfl->end();
++pj)
{
if (pi->field_name() == pj->field_name()
&& !Gogo::is_sink_name(pi->field_name()))
go_error_at(pi->location(), "duplicate field name %<%s%>",
Gogo::message_name(pi->field_name()).c_str());
}
}
return Type::make_struct_type(sfl, location);
}
// FieldDecl = (IdentifierList CompleteType | TypeName) [ Tag ] .
// Tag = string_lit .
void
Parse::field_decl(Struct_field_list* sfl)
{
const Token* token = this->peek_token();
Location location = token->location();
bool is_anonymous;
bool is_anonymous_pointer;
if (token->is_op(OPERATOR_MULT))
{
is_anonymous = true;
is_anonymous_pointer = true;
}
else if (token->is_identifier())
{
std::string id = token->identifier();
bool is_id_exported = token->is_identifier_exported();
Location id_location = token->location();
token = this->advance_token();
is_anonymous = (token->is_op(OPERATOR_SEMICOLON)
|| token->is_op(OPERATOR_RCURLY)
|| token->is_op(OPERATOR_DOT)
|| token->is_string());
is_anonymous_pointer = false;
this->unget_token(Token::make_identifier_token(id, is_id_exported,
id_location));
}
else
{
go_error_at(this->location(), "expected field name");
this->gogo_->mark_locals_used();
while (!token->is_op(OPERATOR_SEMICOLON)
&& !token->is_op(OPERATOR_RCURLY)
&& !token->is_eof())
token = this->advance_token();
return;
}
if (is_anonymous)
{
if (is_anonymous_pointer)
{
this->advance_token();
if (!this->peek_token()->is_identifier())
{
go_error_at(this->location(), "expected field name");
this->gogo_->mark_locals_used();
while (!token->is_op(OPERATOR_SEMICOLON)
&& !token->is_op(OPERATOR_RCURLY)
&& !token->is_eof())
token = this->advance_token();
return;
}
}
Type* type = this->type_name(true);
std::string tag;
if (this->peek_token()->is_string())
{
tag = this->peek_token()->string_value();
this->advance_token();
}
if (!type->is_error_type())
{
if (is_anonymous_pointer)
type = Type::make_pointer_type(type);
sfl->push_back(Struct_field(Typed_identifier("", type, location)));
if (!tag.empty())
sfl->back().set_tag(tag);
}
}
else
{
Typed_identifier_list til;
while (true)
{
token = this->peek_token();
if (!token->is_identifier())
{
go_error_at(this->location(), "expected identifier");
return;
}
std::string name =
this->gogo_->pack_hidden_name(token->identifier(),
token->is_identifier_exported());
til.push_back(Typed_identifier(name, NULL, token->location()));
if (!this->advance_token()->is_op(OPERATOR_COMMA))
break;
this->advance_token();
}
Type* type = this->type();
std::string tag;
if (this->peek_token()->is_string())
{
tag = this->peek_token()->string_value();
this->advance_token();
}
for (Typed_identifier_list::iterator p = til.begin();
p != til.end();
++p)
{
p->set_type(type);
sfl->push_back(Struct_field(*p));
if (!tag.empty())
sfl->back().set_tag(tag);
}
}
}
// PointerType = "*" Type .
Type*
Parse::pointer_type()
{
go_assert(this->peek_token()->is_op(OPERATOR_MULT));
this->advance_token();
Type* type = this->type();
if (type->is_error_type())
return type;
return Type::make_pointer_type(type);
}
// ChannelType = Channel | SendChannel | RecvChannel .
// Channel = "chan" ElementType .
// SendChannel = "chan" "<-" ElementType .
// RecvChannel = "<-" "chan" ElementType .
Type*
Parse::channel_type()
{
const Token* token = this->peek_token();
bool send = true;
bool receive = true;
if (token->is_op(OPERATOR_CHANOP))
{
if (!this->advance_token()->is_keyword(KEYWORD_CHAN))
{
go_error_at(this->location(), "expected %<chan%>");
return Type::make_error_type();
}
send = false;
this->advance_token();
}
else
{
go_assert(token->is_keyword(KEYWORD_CHAN));
if (this->advance_token()->is_op(OPERATOR_CHANOP))
{
receive = false;
this->advance_token();
}
}
// Better error messages for the common error of omitting the
// channel element type.
if (!this->type_may_start_here())
{
token = this->peek_token();
if (token->is_op(OPERATOR_RCURLY))
go_error_at(this->location(), "unexpected %<}%> in channel type");
else if (token->is_op(OPERATOR_RPAREN))
go_error_at(this->location(), "unexpected %<)%> in channel type");
else if (token->is_op(OPERATOR_COMMA))
go_error_at(this->location(), "unexpected comma in channel type");
else
go_error_at(this->location(), "expected channel element type");
return Type::make_error_type();
}
Type* element_type = this->type();
return Type::make_channel_type(send, receive, element_type);
}
// Give an error for a duplicate parameter or receiver name.
void
Parse::check_signature_names(const Typed_identifier_list* params,
Parse::Names* names)
{
for (Typed_identifier_list::const_iterator p = params->begin();
p != params->end();
++p)
{
if (p->name().empty() || Gogo::is_sink_name(p->name()))
continue;
std::pair<std::string, const Typed_identifier*> val =
std::make_pair(p->name(), &*p);
std::pair<Parse::Names::iterator, bool> ins = names->insert(val);
if (!ins.second)
{
go_error_at(p->location(), "redefinition of %qs",
Gogo::message_name(p->name()).c_str());
go_inform(ins.first->second->location(),
"previous definition of %qs was here",
Gogo::message_name(p->name()).c_str());
}
}
}
// Signature = Parameters [ Result ] .
// RECEIVER is the receiver if there is one, or NULL. LOCATION is the
// location of the start of the type.
// This returns NULL on a parse error.
Function_type*
Parse::signature(Typed_identifier* receiver, Location location)
{
bool is_varargs = false;
Typed_identifier_list* params;
bool params_ok = this->parameters(&params, &is_varargs);
Typed_identifier_list* results = NULL;
if (this->peek_token()->is_op(OPERATOR_LPAREN)
|| this->type_may_start_here())
{
if (!this->result(&results))
return NULL;
}
if (!params_ok)
return NULL;
Parse::Names names;
if (receiver != NULL)
names[receiver->name()] = receiver;
if (params != NULL)
this->check_signature_names(params, &names);
if (results != NULL)
this->check_signature_names(results, &names);
Function_type* ret = Type::make_function_type(receiver, params, results,
location);
if (is_varargs)
ret->set_is_varargs();
return ret;
}
// Parameters = "(" [ ParameterList [ "," ] ] ")" .
// This returns false on a parse error.
bool
Parse::parameters(Typed_identifier_list** pparams, bool* is_varargs)
{
*pparams = NULL;
if (!this->peek_token()->is_op(OPERATOR_LPAREN))
{
go_error_at(this->location(), "expected %<(%>");
return false;
}
Typed_identifier_list* params = NULL;
bool saw_error = false;
const Token* token = this->advance_token();
if (!token->is_op(OPERATOR_RPAREN))
{
params = this->parameter_list(is_varargs);
if (params == NULL)
saw_error = true;
token = this->peek_token();
}
// The optional trailing comma is picked up in parameter_list.
if (!token->is_op(OPERATOR_RPAREN))
{
go_error_at(this->location(), "expected %<)%>");
return false;
}
this->advance_token();
if (saw_error)
return false;
*pparams = params;
return true;
}
// ParameterList = ParameterDecl { "," ParameterDecl } .
// This sets *IS_VARARGS if the list ends with an ellipsis.
// IS_VARARGS will be NULL if varargs are not permitted.
// We pick up an optional trailing comma.
// This returns NULL if some error is seen.
Typed_identifier_list*
Parse::parameter_list(bool* is_varargs)
{
Location location = this->location();
Typed_identifier_list* ret = new Typed_identifier_list();
bool saw_error = false;
// If we see an identifier and then a comma, then we don't know
// whether we are looking at a list of identifiers followed by a
// type, or a list of types given by name. We have to do an
// arbitrary lookahead to figure it out.
bool parameters_have_names;
const Token* token = this->peek_token();
if (!token->is_identifier())
{
// This must be a type which starts with something like '*'.
parameters_have_names = false;
}
else
{
std::string name = token->identifier();
bool is_exported = token->is_identifier_exported();
Location location = token->location();
token = this->advance_token();
if (!token->is_op(OPERATOR_COMMA))
{
if (token->is_op(OPERATOR_DOT))
{
// This is a qualified identifier, which must turn out
// to be a type.
parameters_have_names = false;
}
else if (token->is_op(OPERATOR_RPAREN))
{
// A single identifier followed by a parenthesis must be
// a type name.
parameters_have_names = false;
}
else
{
// An identifier followed by something other than a
// comma or a dot or a right parenthesis must be a
// parameter name followed by a type.
parameters_have_names = true;
}
this->unget_token(Token::make_identifier_token(name, is_exported,
location));
}
else
{
// An identifier followed by a comma may be the first in a
// list of parameter names followed by a type, or it may be
// the first in a list of types without parameter names. To
// find out we gather as many identifiers separated by
// commas as we can.
std::string id_name = this->gogo_->pack_hidden_name(name,
is_exported);
ret->push_back(Typed_identifier(id_name, NULL, location));
bool just_saw_comma = true;
while (this->advance_token()->is_identifier())
{
name = this->peek_token()->identifier();
is_exported = this->peek_token()->is_identifier_exported();
location = this->peek_token()->location();
id_name = this->gogo_->pack_hidden_name(name, is_exported);
ret->push_back(Typed_identifier(id_name, NULL, location));
if (!this->advance_token()->is_op(OPERATOR_COMMA))
{
just_saw_comma = false;
break;
}
}
if (just_saw_comma)
{
// We saw ID1 "," ID2 "," followed by something which
// was not an identifier. We must be seeing the start
// of a type, and ID1 and ID2 must be types, and the
// parameters don't have names.
parameters_have_names = false;
}
else if (this->peek_token()->is_op(OPERATOR_RPAREN))
{
// We saw ID1 "," ID2 ")". ID1 and ID2 must be types,
// and the parameters don't have names.
parameters_have_names = false;
}
else if (this->peek_token()->is_op(OPERATOR_DOT))
{
// We saw ID1 "," ID2 ".". ID2 must be a package name,
// ID1 must be a type, and the parameters don't have
// names.
parameters_have_names = false;
this->unget_token(Token::make_identifier_token(name, is_exported,
location));
ret->pop_back();
just_saw_comma = true;
}
else
{
// We saw ID1 "," ID2 followed by something other than
// ",", ".", or ")". We must be looking at the start of
// a type, and ID1 and ID2 must be parameter names.
parameters_have_names = true;
}
if (parameters_have_names)
{
go_assert(!just_saw_comma);
// We have just seen ID1, ID2 xxx.
Type* type;
if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
type = this->type();
else
{
go_error_at(this->location(),
"%<...%> only permits one name");
saw_error = true;
this->advance_token();
type = this->type();
}
for (size_t i = 0; i < ret->size(); ++i)
ret->set_type(i, type);
if (!this->peek_token()->is_op(OPERATOR_COMMA))
return saw_error ? NULL : ret;
if (this->advance_token()->is_op(OPERATOR_RPAREN))
return saw_error ? NULL : ret;
}
else
{
Typed_identifier_list* tret = new Typed_identifier_list();
for (Typed_identifier_list::const_iterator p = ret->begin();
p != ret->end();
++p)
{
Named_object* no = this->gogo_->lookup(p->name(), NULL);
Type* type;
if (no == NULL)
no = this->gogo_->add_unknown_name(p->name(),
p->location());
if (no->is_type())
type = no->type_value();
else if (no->is_unknown() || no->is_type_declaration())
type = Type::make_forward_declaration(no);
else
{
go_error_at(p->location(), "expected %<%s%> to be a type",
Gogo::message_name(p->name()).c_str());
saw_error = true;
type = Type::make_error_type();
}
tret->push_back(Typed_identifier("", type, p->location()));
}
delete ret;
ret = tret;
if (!just_saw_comma
|| this->peek_token()->is_op(OPERATOR_RPAREN))
return saw_error ? NULL : ret;
}
}
}
bool mix_error = false;
this->parameter_decl(parameters_have_names, ret, is_varargs, &mix_error,
&saw_error);
while (this->peek_token()->is_op(OPERATOR_COMMA))
{
if (this->advance_token()->is_op(OPERATOR_RPAREN))
break;
if (is_varargs != NULL && *is_varargs)
{
go_error_at(this->location(), "%<...%> must be last parameter");
saw_error = true;
}
this->parameter_decl(parameters_have_names, ret, is_varargs, &mix_error,
&saw_error);
}
if (mix_error)
{
go_error_at(location, "invalid named/anonymous mix");
saw_error = true;
}
if (saw_error)
{
delete ret;
return NULL;
}
return ret;
}
// ParameterDecl = [ IdentifierList ] [ "..." ] Type .
void
Parse::parameter_decl(bool parameters_have_names,
Typed_identifier_list* til,
bool* is_varargs,
bool* mix_error,
bool* saw_error)
{
if (!parameters_have_names)
{
Type* type;
Location location = this->location();
if (!this->peek_token()->is_identifier())
{
if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
type = this->type();
else
{
if (is_varargs == NULL)
go_error_at(this->location(), "invalid use of %<...%>");
else
*is_varargs = true;
this->advance_token();
if (is_varargs == NULL
&& this->peek_token()->is_op(OPERATOR_RPAREN))
type = Type::make_error_type();
else
{
Type* element_type = this->type();
type = Type::make_array_type(element_type, NULL);
}
}
}
else
{
type = this->type_name(false);
if (type->is_error_type()
|| (!this->peek_token()->is_op(OPERATOR_COMMA)
&& !this->peek_token()->is_op(OPERATOR_RPAREN)))
{
*mix_error = true;
while (!this->peek_token()->is_op(OPERATOR_COMMA)
&& !this->peek_token()->is_op(OPERATOR_RPAREN)
&& !this->peek_token()->is_eof())
this->advance_token();
}
}
if (!type->is_error_type())
til->push_back(Typed_identifier("", type, location));
else
*saw_error = true;
}
else
{
size_t orig_count = til->size();
if (this->peek_token()->is_identifier())
this->identifier_list(til);
else
*mix_error = true;
size_t new_count = til->size();
Type* type;
if (!this->peek_token()->is_op(OPERATOR_ELLIPSIS))
type = this->type();
else
{
if (is_varargs == NULL)
{
go_error_at(this->location(), "invalid use of %<...%>");
*saw_error = true;
}
else if (new_count > orig_count + 1)
{
go_error_at(this->location(), "%<...%> only permits one name");
*saw_error = true;
}
else
*is_varargs = true;
this->advance_token();
Type* element_type = this->type();
type = Type::make_array_type(element_type, NULL);
}
for (size_t i = orig_count; i < new_count; ++i)
til->set_type(i, type);
}
}
// Result = Parameters | Type .
// This returns false on a parse error.
bool
Parse::result(Typed_identifier_list** presults)
{
if (this->peek_token()->is_op(OPERATOR_LPAREN))
return this->parameters(presults, NULL);
else
{
Location location = this->location();
Type* type = this->type();
if (type->is_error_type())
{
*presults = NULL;
return false;
}
Typed_identifier_list* til = new Typed_identifier_list();
til->push_back(Typed_identifier("", type, location));
*presults = til;
return true;
}
}
// Block = "{" [ StatementList ] "}" .
// Returns the location of the closing brace.
Location
Parse::block()
{
if (!this->peek_token()->is_op(OPERATOR_LCURLY))
{
Location loc = this->location();
if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
&& this->advance_token()->is_op(OPERATOR_LCURLY))
go_error_at(loc, "unexpected semicolon or newline before %<{%>");
else
{
go_error_at(this->location(), "expected %<{%>");
return Linemap::unknown_location();
}
}
const Token* token = this->advance_token();
if (!token->is_op(OPERATOR_RCURLY))
{
this->statement_list();
token = this->peek_token();
if (!token->is_op(OPERATOR_RCURLY))
{
if (!token->is_eof() || !saw_errors())
go_error_at(this->location(), "expected %<}%>");
this->gogo_->mark_locals_used();
// Skip ahead to the end of the block, in hopes of avoiding
// lots of meaningless errors.
Location ret = token->location();
int nest = 0;
while (!token->is_eof())
{
if (token->is_op(OPERATOR_LCURLY))
++nest;
else if (token->is_op(OPERATOR_RCURLY))
{
--nest;
if (nest < 0)
{
this->advance_token();
break;
}
}
token = this->advance_token();
ret = token->location();
}
return ret;
}
}
Location ret = token->location();
this->advance_token();
return ret;
}
// InterfaceType = "interface" "{" [ MethodSpecList ] "}" .
// MethodSpecList = MethodSpec { ";" MethodSpec } [ ";" ] .
Type*
Parse::interface_type(bool record)
{
go_assert(this->peek_token()->is_keyword(KEYWORD_INTERFACE));
Location location = this->location();
if (!this->advance_token()->is_op(OPERATOR_LCURLY))
{
Location token_loc = this->location();
if (this->peek_token()->is_op(OPERATOR_SEMICOLON)
&& this->advance_token()->is_op(OPERATOR_LCURLY))
go_error_at(token_loc, "unexpected semicolon or newline before %<{%>");
else
{
go_error_at(this->location(), "expected %<{%>");
return Type::make_error_type();
}
}
this->advance_token();
Typed_identifier_list* methods = new Typed_identifier_list();
if (!this->peek_token()->is_op(OPERATOR_RCURLY))
{
this->method_spec(methods);
while (this->peek_token()->is_op(OPERATOR_SEMICOLON))
{
if (this->advance_token()->is_op(OPERATOR_RCURLY))
break;
this->method_spec(methods);
}
if (!this->peek_token()->is_op(OPERATOR_RCURLY))
{
go_error_at(this->location(), "expected %<}%>");
while (!this->advance_token()->is_op(OPERATOR_RCURLY))
{
if (this->peek_token()->is_eof())
return Type::make_error_type();
}
}
}
this->advance_token();
if (methods->empty())
{
delete methods;
methods = NULL;
}
Interface_type* ret;
if (methods == NULL)
ret = Type::make_empty_interface_type(location);
else
ret = Type::make_interface_type(methods, location);
if (record)
this->gogo_->record_interface_type(ret);
return ret;
}
// MethodSpec = MethodName Signature | InterfaceTypeName .
// MethodName = identifier .
// InterfaceTypeName = TypeName .
void
Parse::method_spec(Typed_identifier_list* methods)
{
const Token* token = this->peek_token();
if (!token->is_identifier())
{
go_error_at(this->location(), "expected identifier");
return;
}
std::string name = token->identifier();
bool is_exported = token->is_identifier_exported();
Location location = token->location();
if (this->advance_token()->is_op(OPERATOR_LPAREN))
{
// This is a MethodName.
if (name == "_")
go_error_at(this->location(),
"methods must have a unique non-blank name");
name = this->gogo_->pack_hidden_name(name, is_exported);
Type* type = this->signature(NULL, location);
if (type == NULL)
return;
methods->push_back(Typed_identifier(name, type, location));
}
else
{
this->unget_token(Token::make_identifier_token(name, is_exported,
location));
Type* type = this->type_name(false);
if (type->is_error_type()
|| (!this->peek_token()->is_op(OPERATOR_SEMICOLON)
&& !this->peek_token()->is_op(OPERATOR_RCURLY)))
{
if (this->peek_token()->is_op(OPERATOR_COMMA))
go_error_at(this->location(),
"name list not allowed in interface type");
else
go_error_at(location, "expected signature or type name");
this->gogo_->mark_locals_used();
token = this->peek_token();
while (!token->is_eof()
&& !token->is_op(OPERATOR_SEMICOLON)
&& !token->is_op(OPERATOR_RCURLY))
token = this->advance_token();
return;
}
// This must be an interface type, but we can't check that now.
// We check it and pull out the methods in
// Interface_type::do_verify.
methods->push_back(Typed_identifier("", type, location));
}
}
// Declaration = ConstDecl | TypeDecl | VarDecl | FunctionDecl | MethodDecl .
void
Parse::declaration()
{
const Token* token = this->peek_token();
unsigned int pragmas = this->lex_->get_and_clear_pragmas();
if (pragmas != 0
&& !token->is_keyword(KEYWORD_FUNC)
&& !token->is_keyword(KEYWORD_TYPE))
go_warning_at(token->location(), 0,
"ignoring magic comment before non-function");
if (token->is_keyword(KEYWORD_CONST))
this->const_decl();
else if (token->is_keyword(KEYWORD_TYPE))
this->type_decl(pragmas);
else if (token->is_keyword(KEYWORD_VAR))
this->var_decl();
else if (token->is_keyword(KEYWORD_FUNC))
this->function_decl(pragmas);
else
{
go_error_at(this->location(), "expected declaration");
this->advance_token();
}
}
bool
Parse::declaration_may_start_here()
{
const Token* token = this->peek_token();
return (token->is_keyword(KEYWORD_CONST)
|| token->is_keyword(KEYWORD_TYPE)
|| token->is_keyword(KEYWORD_VAR)
|| token->is_keyword(KEYWORD_FUNC));
}
// Decl<P> = P | "(" [ List<P> ] ")" .
void
Parse::decl(void (Parse::*pfn)(void*, unsigned int), void* varg,
unsigned int pragmas)
{
if (this->peek_token()->is_eof())
{
if (!saw_errors())
go_error_at(this->location(), "unexpected end of file");
return;
}
if (!this->peek_token()->is_op(OPERATOR_LPAREN))
(this->*pfn)(varg, pragmas);
else
{
if (pragmas != 0)
go_warning_at(this->location(), 0,
"ignoring magic //go:... comment before group");
if (!this->advance_token()->is_op(OPERATOR_RPAREN))
{
this->list(pfn, varg, true);
if (!this->peek_token()->is_op(OPERATOR_RPAREN))
{
go_error_at(this->location(), "missing %<)%>");
while (!this->advance_token()->is_op(OPERATOR_RPAREN))
{
if (this->peek_token()->is_eof())
return;
}
}
}
this->advance_token();
}
}
// List<P> = P { ";" P } [ ";" ] .
// In order to pick up the trailing semicolon we need to know what
// might follow. This is either a '}' or a ')'.
void
Parse::list(void (Parse::*pfn)(void*, unsigned int), void* varg,
bool follow_is_paren)
{
(this->*pfn)(varg, 0);
Operator follow = follow_is_paren ? OPERATOR_RPAREN : OPERATOR_RCURLY;
while (this->peek_token()->is_op(OPERATOR_SEMICOLON)
|| this->peek_token()->is_op(OPERATOR_COMMA))
{
if (this->peek_token()->is_op(OPERATOR_COMMA))
go_error_at(this->location(), "unexpected comma");
if (this->advance_token()->is_op(follow))
break;
(this->*pfn)(varg, 0);
}
}
// ConstDecl = "const" ( ConstSpec | "(" { ConstSpec ";" } ")" ) .
void
Parse::const_decl()
{
go_assert(this->peek_token()->is_keyword(KEYWORD_CONST));
this->advance_token();
int iota = 0;
Type* last_type = NULL;
Expression_list* last_expr_list = NULL;
if (!this->peek_token()->is_op(OPERATOR_LPAREN))
this->const_spec(iota, &last_type, &last_expr_list);
else
{
this->advance_token();
while (!this->peek_token()->is_op(OPERATOR_RPAREN))
{
this->const_spec(iota, &last_type, &last_expr_list);
++iota;
if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
this->advance_token();
else if (!this->peek_token()->is_op(OPERATOR_RPAREN))
{
go_error_at(this->location(),
"expected %<;%> or %<)%> or newline");
if (!this->skip_past_error(OPERATOR_RPAREN))
return;
}
}
this->advance_token();
}
if (last_expr_list != NULL)
delete last_expr_list;
}
// ConstSpec = IdentifierList [ [ CompleteType ] "=" ExpressionList ] .
void
Parse::const_spec(int iota, Type** last_type, Expression_list** last_expr_list)
{
Typed_identifier_list til;
this->identifier_list(&til);
Type* type = NULL;
if (this->type_may_start_here())
{
type = this->type();
*last_type = NULL;
*last_expr_list = NULL;
}
Expression_list *expr_list;
if (!this->peek_token()->is_op(OPERATOR_EQ))
{
if (*last_expr_list == NULL)
{
go_error_at(this->location(), "expected %<=%>");
return;
}
type = *last_type;
expr_list = new Expression_list;
for (Expression_list::const_iterator p = (*last_expr_list)->begin();
p != (*last_expr_list)->end();
++p)
expr_list->push_back((*p)->copy());
}
else
{
this->advance_token();
expr_list = this->expression_list(NULL, false, true);
*last_type = type;
if (*last_expr_list != NULL)
delete *last_expr_list;
*last_expr_list = expr_list;
}
Expression_list::const_iterator pe = expr_list->begin();
for (Typed_identifier_list::iterator pi = til.begin();
pi != til.end();
++pi, ++pe)
{
if (pe == expr_list->end())
{
go_error_at(this->location(), "not enough initializers");
return;
}
if (type != NULL)
pi->set_type(type);
if (!Gogo::is_sink_name(pi->name()))
this->gogo_->add_constant(*pi, *pe, iota);
else
{
static int count;
char buf[30];
snprintf(buf, sizeof buf, ".$sinkconst%d", count);
++count;
Typed_identifier ti(std::string(buf), type, pi->location());
Named_object* no = this->gogo_->add_constant(ti, *pe, iota);
no->const_value()->set_is_sink();
}
}
if (pe != expr_list->end())
go_error_at(this->location(), "too many initializers");
return;
}
// TypeDecl = "type" Decl<TypeSpec> .
void
Parse::type_decl(unsigned int pragmas)
{
go_assert(this->peek_token()->is_keyword(KEYWORD_TYPE));
this->advance_token();
this->decl(&Parse::type_spec, NULL, pragmas);
}
// TypeSpec = identifier ["="] Type .
void
Parse::type_spec(void*, unsigned int pragmas)
{
const Token* token = this->peek_token();
if (!token->is_identifier())
{
go_error_at(this->location(), "expected identifier");
return;
}
std::string name = token->identifier();
bool is_exported = token->is_identifier_exported();
Location location = token->location();
token = this->advance_token();
bool is_alias = false;
if (token->is_op(OPERATOR_EQ))
{
is_alias = true;
token = this->advance_token();
}
// The scope of the type name starts at the point where the
// identifier appears in the source code. We implement this by
// declaring the type before we read the type definition.
Named_object* named_type = NULL;
if (name != "_")
{
name = this->gogo_->pack_hidden_name(name, is_exported);
named_type = this->gogo_->declare_type(name, location);
}
Type* type;
if (name == "_" && token->is_keyword(KEYWORD_INTERFACE))
{
// We call Parse::interface_type explicity here because we do not want
// to record an interface with a blank type name.
type = this->interface_type(false);
}
else if (!token->is_op(OPERATOR_SEMICOLON))
type = this->type();
else
{
go_error_at(this->location(),
"unexpected semicolon or newline in type declaration");
type = Type::make_error_type();
this->advance_token();
}
if (type->is_error_type())
{
this->gogo_->mark_locals_used();
while (!this->peek_token()->is_op(OPERATOR_SEMICOLON)
&& !this->peek_token()->is_eof())
this->advance_token();
}
if (name != "_")
{
if (named_type->is_type_declaration())
{
Type* ftype = type->forwarded();
if (ftype->forward_declaration_type() != NULL
&& (ftype->forward_declaration_type()->named_object()
== named_type))
{
go_error_at(location, "invalid recursive type");
type = Type::make_error_type();
}
Named_type* nt = Type::make_named_type(named_type, type, location);
if (is_alias)
nt->set_is_alias();
this->gogo_->define_type(named_type, nt);
go_assert(named_type->package() == NULL);
if ((pragmas & GOPRAGMA_NOTINHEAP) != 0)
{
nt->set_not_in_heap();
pragmas &= ~GOPRAGMA_NOTINHEAP;
}
if (pragmas != 0)
go_warning_at(location, 0,
"ignoring magic //go:... comment before type");
}
else
{
// This will probably give a redefinition error.
this->gogo_->add_type(name, type, location);
}
}
}
// VarDecl = "var" Decl<VarSpec> .
void
Parse::var_decl()
{
go_assert(this->peek_token()->is_keyword(KEYWORD_VAR));
this->advance_token();
this->decl(&Parse::var_spec, NULL, 0);
}
// VarSpec = IdentifierList
// ( CompleteType [ "=" ExpressionList ] | "=" ExpressionList ) .
void
Parse::var_spec(void*, unsigned int pragmas)
{
if (pragmas != 0)
go_warning_at(this->location(), 0,
"ignoring magic //go:... comment before var");
// Get the variable names.
Typed_identifier_list til;
this->identifier_list(&til);
Location location = this->location();
Type* type = NULL;
Expression_list* init = NULL;
if (!this->peek_token()->is_op(OPERATOR_EQ))
{
type = this->type();
if (type->is_error_type())
{
this->gogo_->mark_locals_used();
while (!this->peek_token()->is_op(OPERATOR_EQ)
&& !this->peek_token()->is_op(OPERATOR_SEMICOLON)
&& !this->peek_token()->is_eof())
this->advance_token();
}
if (this->peek_token()->is_op(OPERATOR_EQ))
{
this->advance_token();
init = this->expression_list(NULL, false, true);
}
}
else
{
this->advance_token();
init = this->expression_list(NULL, false, true);
}
this->init_vars(&til, type, init, false, location);
if (init != NULL)
delete init;
}
// Create variables. TIL is a list of variable names. If TYPE is not
// NULL, it is the type of all the variables. If INIT is not NULL, it
// is an initializer list for the variables.
void
Parse::init_vars(const Typed_identifier_list* til, Type* type,
Expression_list* init, bool is_coloneq,
Location location)
{
// Check for an initialization which can yield multiple values.
if (init != NULL && init->size() == 1 && til->size() > 1)
{
if (this->init_vars_from_call(til, type, *init->begin(), is_coloneq,
location))
return;
if (this->init_vars_from_map(til, type, *init->begin(), is_coloneq,
location))
return;
if (this->init_vars_from_receive(til, type, *init->begin(), is_coloneq,
location))
return;
if (this->init_vars_from_type_guard(til, type, *init->begin(),
is_coloneq, location))
return;
}
if (init != NULL && init->size() != til->size())
{
if (init->empty() || !init->front()->is_error_expression())
go_error_at(location, "wrong number of initializations");
init = NULL;
if (type == NULL)
type = Type::make_error_type();
}
// Note that INIT was already parsed with the old name bindings, so
// we don't have to worry that it will accidentally refer to the
// newly declared variables. But we do have to worry about a mix of
// newly declared variables and old variables if the old variables
// appear in the initializations.
Expression_list::const_iterator pexpr;
if (init != NULL)
pexpr = init->begin();
bool any_new = false;
Expression_list* vars = new Expression_list();
Expression_list* vals = new Expression_list();
for (Typed_identifier_list::const_iterator p = til->begin();
p != til->end();
++p)
{
if (init != NULL)
go_assert(pexpr != init->end());
this->init_var(*p, type, init == NULL ? NULL : *pexpr, is_coloneq,
false, &any_new, vars, vals);
if (init != NULL)
++pexpr;
}
if (init != NULL)
go_assert(pexpr == init->end());
if (is_coloneq && !any_new)
go_error_at(location, "variables redeclared but no variable is new");
this->finish_init_vars(vars, vals, location);
}
// See if we need to initialize a list of variables from a function
// call. This returns true if we have set up the variables and the
// initialization.
bool
Parse::init_vars_from_call(const Typed_identifier_list* vars, Type* type,
Expression* expr, bool is_coloneq,
Location location)
{
Call_expression* call = expr->call_expression();
if (call == NULL)
return false;
// This is a function call. We can't check here whether it returns
// the right number of values, but it might. Declare the variables,
// and then assign the results of the call to them.
call->set_expected_result_count(vars->size());
Named_object* first_var = NULL;
unsigned int index = 0;
bool any_new = false;
Expression_list* ivars = new Expression_list();
Expression_list* ivals = new Expression_list();
for (Typed_identifier_list::const_iterator pv = vars->begin();
pv != vars->end();
++pv, ++index)
{
Expression* init = Expression::make_call_result(call, index);
Named_object* no = this->init_var(*pv, type, init, is_coloneq, false,
&any_new, ivars, ivals);
if (this->gogo_->in_global_scope() && no->is_variable())
{
if (first_var == NULL)
first_var = no;
else
{
// If the current object is a redefinition of another object, we
// might have already recorded the dependency relationship between
// it and the first variable. Either way, an error will be
// reported for the redefinition and we don't need to properly
// record dependency information for an invalid program.
if (no->is_redefinition())
continue;
// The subsequent vars have an implicit dependency on
// the first one, so that everything gets initialized in
// the right order and so that we detect cycles
// correctly.
this->gogo_->record_var_depends_on(no->var_value(), first_var);
}
}
}
if (is_coloneq && !any_new)
go_error_at(location, "variables redeclared but no variable is new");
this->finish_init_vars(ivars, ivals, location);
return true;
}
// See if we need to initialize a pair of values from a map index
// expression. This returns true if we have set up the variables and
// the initialization.
bool
Parse::init_vars_from_map(const Typed_identifier_list* vars, Type* type,
Expression* expr, bool is_coloneq,
Location location)
{
Index_expression* index = expr->index_expression();
if (index == NULL)
return false;
if (vars->size() != 2)
return false;
// This is an index which is being assigned to two variables. It
// must be a map index. Declare the variables, and then assign the
// results of the map index.
bool any_new = false;
Typed_identifier_list::const_iterator p = vars->begin();
Expression* init = type == NULL ? index : NULL;
Named_object* val_no = this->init_var(*p, type, init, is_coloneq,
type == NULL, &any_new, NULL, NULL);
if (type == NULL && any_new && val_no->is_variable())
val_no->var_value()->set_type_from_init_tuple();
Expression* val_var = Expression::make_var_reference(val_no, location);
++p;
Type* var_type = type;
if (var_type == NULL)
var_type = Type::lookup_bool_type();
Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
&any_new, NULL, NULL);
Expression* present_var = Expression::make_var_reference(no, location);
if (is_coloneq && !any_new)
go_error_at(location, "variables redeclared but no variable is new");
Statement* s = Statement::make_tuple_map_assignment(val_var, present_var,
index, location);
if (!this->gogo_->in_global_scope())
this->gogo_->add_statement(s);
else if (!val_no->is_sink())
{
if (val_no->is_variable())
val_no->var_value()->add_preinit_statement(this->gogo_, s);
}
else if (!no->is_sink())
{
if (no->is_variable())
no->var_value()->add_preinit_statement(this->gogo_, s);
}
else
{
// Execute the map index expression just so that we can fail if
// the map is nil.
Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
NULL, location);
dummy->var_value()->add_preinit_statement(this->gogo_, s);
}
return true;
}
// See if we need to initialize a pair of values from a receive
// expression. This returns true if we have set up the variables and
// the initialization.
bool
Parse::init_vars_from_receive(const Typed_identifier_list* vars, Type* type,
Expression* expr, bool is_coloneq,
Location location)
{
Receive_expression* receive = expr->receive_expression();
if (receive == NULL)
return false;
if (vars->size() != 2)
return false;
// This is a receive expression which is being assigned to two
// variables. Declare the variables, and then assign the results of
// the receive.
bool any_new = false;
Typed_identifier_list::const_iterator p = vars->begin();
Expression* init = type == NULL ? receive : NULL;
Named_object* val_no = this->init_var(*p, type, init, is_coloneq,
type == NULL, &any_new, NULL, NULL);
if (type == NULL && any_new && val_no->is_variable())
val_no->var_value()->set_type_from_init_tuple();
Expression* val_var = Expression::make_var_reference(val_no, location);
++p;
Type* var_type = type;
if (var_type == NULL)
var_type = Type::lookup_bool_type();
Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
&any_new, NULL, NULL);
Expression* received_var = Expression::make_var_reference(no, location);
if (is_coloneq && !any_new)
go_error_at(location, "variables redeclared but no variable is new");
Statement* s = Statement::make_tuple_receive_assignment(val_var,
received_var,
receive->channel(),
location);
if (!this->gogo_->in_global_scope())
this->gogo_->add_statement(s);
else if (!val_no->is_sink())
{
if (val_no->is_variable())
val_no->var_value()->add_preinit_statement(this->gogo_, s);
}
else if (!no->is_sink())
{
if (no->is_variable())
no->var_value()->add_preinit_statement(this->gogo_, s);
}
else
{
Named_object* dummy = this->create_dummy_global(Type::lookup_bool_type(),
NULL, location);
dummy->var_value()->add_preinit_statement(this->gogo_, s);
}
return true;
}
// See if we need to initialize a pair of values from a type guard
// expression. This returns true if we have set up the variables and
// the initialization.
bool
Parse::init_vars_from_type_guard(const Typed_identifier_list* vars,
Type* type, Expression* expr,
bool is_coloneq, Location location)
{
Type_guard_expression* type_guard = expr->type_guard_expression();
if (type_guard == NULL)
return false;
if (vars->size() != 2)
return false;
// This is a type guard expression which is being assigned to two
// variables. Declare the variables, and then assign the results of
// the type guard.
bool any_new = false;
Typed_identifier_list::const_iterator p = vars->begin();
Type* var_type = type;
if (var_type == NULL)
var_type = type_guard->type();
Named_object* val_no = this->init_var(*p, var_type, NULL, is_coloneq, false,
&any_new, NULL, NULL);
Expression* val_var = Expression::make_var_reference(val_no, location);
++p;
var_type = type;
if (var_type == NULL)
var_type = Type::lookup_bool_type();
Named_object* no = this->init_var(*p, var_type, NULL, is_coloneq, false,
&any_new, NULL, NULL);
Expression* ok_var = Expression::make_var_reference(no, location);
Expression* texpr = type_guard->expr();
Type* t = type_guard->type();
Statement* s = Statement::make_tuple_type_guard_assignment(val_var, ok_var,
texpr, t,
location);
if (is_coloneq && !any_new)
go_error_at(location, "variables redeclared but no variable is new");
if (!this->gogo_->in_global_scope())
this->gogo_->add_statement(s);
else if (!val_no->is_sink())
{
if (val_no->is_variable())
val_no->var_value()->add_preinit_statement(this->gogo_, s);
}
else if (!no->is_sink())
{
if (no->is_variable())
no->var_value()->add_preinit_statement(this->gogo_, s);
}
else
{
Named_object* dummy = this->create_dummy_global(type, NULL, location);
dummy->var_value()->add_preinit_statement(this->gogo_, s);
}
return true;
}
// Create a single variable. If IS_COLONEQ is true, we permit
// redeclarations in the same block, and we set *IS_NEW when we find a
// new variable which is not a redeclaration.
Named_object*
Parse::init_var(const Typed_identifier& tid, Type* type, Expression* init,
bool is_coloneq, bool type_from_init, bool* is_new,
Expression_list* vars, Expression_list* vals)
{
Location location = tid.location();
if (Gogo::is_sink_name(tid.name()))
{
if (!type_from_init && init != NULL)
{
if (this->gogo_->in_global_scope())
return this->create_dummy_global(type, init, location);
else
{
// Create a dummy variable so that we will check whether the
// initializer can be assigned to the type.
Variable* var = new Variable(type, init, false, false, false,
location);
var->set_is_used();
static int count;
char buf[30];
snprintf(buf, sizeof buf, "sink$%d", count);
++count;
return this->gogo_->add_variable(buf, var);
}
}
if (type != NULL)
this->gogo_->add_type_to_verify(type);
return this->gogo_->add_sink();
}
if (is_coloneq)
{
Named_object* no = this->gogo_->lookup_in_block(tid.name());
if (no != NULL
&& (no->is_variable() || no->is_result_variable()))
{
// INIT may be NULL even when IS_COLONEQ is true for cases
// like v, ok := x.(int).
if (!type_from_init && init != NULL)
{
go_assert(vars != NULL && vals != NULL);
vars->push_back(Expression::make_var_reference(no, location));
vals->push_back(init);
}
return no;
}
}
*is_new = true;
Variable* var = new Variable(type, init, this->gogo_->in_global_scope(),
false, false, location);
Named_object* no = this->gogo_->add_variable(tid.name(), var);
if (!no->is_variable())
{
// The name is already defined, so we just gave an error.
return this->gogo_->add_sink();
}
return no;
}
// Create a dummy global variable to force an initializer to be run in
// the right place. This is used when a sink variable is initialized
// at global scope.
Named_object*
Parse::create_dummy_global(Type* type, Expression* init,
Location location)
{
if (type == NULL && init == NULL)
type = Type::lookup_bool_type();
Variable* var = new Variable(type, init, true, false, false, location);
static int count;
char buf[30];
snprintf(buf, sizeof buf, "_.%d", count);
++count;
return this->gogo_->add_variable(buf, var);
}
// Finish the variable initialization by executing any assignments to
// existing variables when using :=. These must be done as a tuple
// assignment in case of something like n, a, b := 1, b, a.
void
Parse::finish_init_vars(Expression_list* vars, Expression_list* vals,
Location location)
{
if (vars->empty())
{
delete vars;
delete vals;
}
else if (vars->size() == 1)
{
go_assert(!this->gogo_->in_global_scope());
this->gogo_->add_statement(Statement::make_assignment(vars->front(),
vals->front(),
location));
delete vars;
delete vals;
}
else
{
go_assert(!this->gogo_->in_global_scope());
this->gogo_->add_statement(Statement::make_tuple_assignment(vars, vals,
location));
}
}
// SimpleVarDecl = identifier ":=" Expression .
// We've already seen the identifier.
// FIXME: We also have to implement
// IdentifierList ":=" ExpressionList
// In order to support both "a, b := 1, 0" and "a, b = 1, 0" we accept
// tuple assignments here as well.
// If MAY_BE_COMPOSITE_LIT is true, the expression on the right hand
// side may be a composite literal.
// If P_RANGE_CLAUSE is not NULL, then this will recognize a
// RangeClause.
// If P_TYPE_SWITCH is not NULL, this will recognize a type switch
// guard (var := expr.("type") using the literal keyword "type").
void
Parse::simple_var_decl_or_assignment(const std::string& name,
Location location,
bool may_be_composite_lit,
Range_clause* p_range_clause,
Type_switch* p_type_switch)
{
Typed_identifier_list til;
til.push_back(Typed_identifier(name, NULL, location));
std::set<std::string> uniq_idents;
uniq_idents.insert(name);
std::string dup_name;
Location dup_loc;
// We've seen one identifier. If we see a comma now, this could be
// "a, *p = 1, 2".
if (this->peek_token()->is_op(OPERATOR_COMMA))
{
go_assert(p_type_switch == NULL);
while (true)
{
const Token* token = this->advance_token();
if (!token->is_identifier())
break;
std::string id = token->identifier();
bool is_id_exported = token->is_identifier_exported();
Location id_location = token->location();
std::pair<std::set<std::string>::iterator, bool> ins;
token = this->advance_token();
if (!token->is_op(OPERATOR_COMMA))
{
if (token->is_op(OPERATOR_COLONEQ))
{
id = this->gogo_->pack_hidden_name(id, is_id_exported);
ins = uniq_idents.insert(id);
if (!ins.second && !Gogo::is_sink_name(id))
go_error_at(id_location, "multiple assignments to %s",
Gogo::message_name(id).c_str());
til.push_back(Typed_identifier(id, NULL, location));
}
else
this->unget_token(Token::make_identifier_token(id,
is_id_exported,
id_location));
break;
}
id = this->gogo_->pack_hidden_name(id, is_id_exported);
ins = uniq_idents.insert(id);
if (!ins.second && !Gogo::is_sink_name(id))
{
dup_name = Gogo::message_name(id);
dup_loc = id_location;
}
til.push_back(Typed_identifier(id, NULL, location));
}
// We have a comma separated list of identifiers in TIL. If the
// next token is COLONEQ, then this is a simple var decl, and we
// have the complete list of identifiers. If the next token is
// not COLONEQ, then the only valid parse is a tuple assignment.
// The list of identifiers we have so far is really a list of
// expressions. There are more expressions following.
if (!this->peek_token()->is_op(OPERATOR_COLONEQ))
{
Expression_list* exprs = new Expression_list;
for (Typed_identifier_list::const_iterator p = til.begin();
p != til.end();
++p)
exprs->push_back(this->id_to_expression(p->name(), p->location(),
true));
Expression_list* more_exprs =
this->expression_list(NULL, true, may_be_composite_lit);
for (Expression_list::const_iterator p = more_exprs->begin();
p != more_exprs->end();
++p)
exprs->push_back(*p);
delete more_exprs;
this->tuple_assignment(exprs, may_be_composite_lit, p_range_clause);
return;
}
}
go_assert(this->peek_token()->is_op(OPERATOR_COLONEQ));
const Token* token = this->advance_token();
if (!dup_name.empty())
go_error_at(dup_loc, "multiple assignments to %s", dup_name.c_str());
if (p_range_clause != NULL && token->is_keyword(KEYWORD_RANGE))
{
this->range_clause_decl(&til, p_range_clause);
return;
}
Expression_list* init;
if (p_type_switch == NULL)
init = this->expression_list(NULL, false, may_be_composite_lit);
else
{
bool is_type_switch = false;
Expression* expr = this->expression(PRECEDENCE_NORMAL, false,
may_be_composite_lit,
&is_type_switch, NULL);
if (is_type_switch)
{
p_type_switch->found = true;
p_type_switch->name = name;
p_type_switch->location = location;
p_type_switch->expr = expr;
return;
}
if (!this->peek_token()->is_op(OPERATOR_COMMA))
{
init = new Expression_list();
init->push_back(expr);
}
else
{
this->advance_token();
init = this->expression_list(expr, false, may_be_composite_lit);
}
}
this->init_vars(&til, NULL, init, true, location);
}
// FunctionDecl = "func" identifier Signature [ Block ] .
// MethodDecl = "func" Receiver identifier Signature [ Block ] .
// Deprecated gcc extension:
// FunctionDecl = "func" identifier Signature
// __asm__ "(" string_lit ")" .
// This extension means a function whose real name is the identifier
// inside the asm. This extension will be removed at some future
// date. It has been replaced with //extern or //go:linkname comments.
//
// PRAGMAS is a bitset of magic comments.
void
Parse::function_decl(unsigned int pragmas)
{
go_assert(this->peek_token()->is_keyword(KEYWORD_FUNC));
Location location = this->location();
std::string extern_name = this->lex_->extern_name();
const Token* token = this->advance_token();
bool expected_receiver = false;
Typed_identifier* rec = NULL;
if (token->is_op(OPERATOR_LPAREN))
{
expected_receiver = true;
rec = this->receiver();
token = this->peek_token();
}
if (!token->is_identifier())
{
go_error_at(this->location(), "expected function name");
return;
}
std::string name =
this->gogo_->pack_hidden_name(token->identifier(),
token->is_identifier_exported());
this->advance_token();
Function_type* fntype = this->signature(rec, this->location());
Named_object* named_object = NULL;
if (this->peek_token()->is_keyword(KEYWORD_ASM))
{
if (!this->advance_token()->is_op(OPERATOR_LPAREN))
{
go_error_at(this->location(), "expected %<(%>");
return;
}
token = this->advance_token();
if (!token->is_string())
{
go_error_at(this->location(), "expected string");
return;
}
std::string asm_name = token->string_value();
if (!this->advance_token()->is_op(OPERATOR_RPAREN))
{
go_error_at(this->location(), "expected %<)%>");
return;
}
this->advance_token();
if (!Gogo::is_sink_name(name))
{
named_object = this->gogo_->declare_function(name, fntype, location);
if (named_object->is_function_declaration())
named_object->func_declaration_value()->set_asm_name(asm_name);
}
}
// Check for the easy error of a newline before the opening brace.
if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
{
Location semi_loc = this->location();
if (this->advance_token()->is_op(OPERATOR_LCURLY))
go_error_at(this->location(),
"unexpected semicolon or newline before %<{%>");
else
this->unget_token(Token::make_operator_token(OPERATOR_SEMICOLON,
semi_loc));
}
static struct {
unsigned int bit;
const char* name;
bool decl_ok;
bool func_ok;
bool method_ok;
} pragma_check[] =
{
{ GOPRAGMA_NOINTERFACE, "nointerface", false, false, true },
{ GOPRAGMA_NOESCAPE, "noescape", true, false, false },
{ GOPRAGMA_NORACE, "norace", false, true, true },
{ GOPRAGMA_NOSPLIT, "nosplit", false, true, true },
{ GOPRAGMA_NOINLINE, "noinline", false, true, true },
{ GOPRAGMA_SYSTEMSTACK, "systemstack", false, true, true },
{ GOPRAGMA_NOWRITEBARRIER, "nowritebarrier", false, true, true },
{ GOPRAGMA_NOWRITEBARRIERREC, "nowritebarrierrec", false, true,
true },
{ GOPRAGMA_YESWRITEBARRIERREC, "yeswritebarrierrec", false, true,
true },
{ GOPRAGMA_CGOUNSAFEARGS, "cgo_unsafe_args", false, true, true },
{ GOPRAGMA_UINTPTRESCAPES, "uintptrescapes", true, true, true },
};
bool is_decl = !this->peek_token()->is_op(OPERATOR_LCURLY);
if (pragmas != 0)
{
for (size_t i = 0;
i < sizeof(pragma_check) / sizeof(pragma_check[0]);
++i)
{
if ((pragmas & pragma_check[i].bit) == 0)
continue;
if (is_decl)
{
if (pragma_check[i].decl_ok)
continue;
go_warning_at(location, 0,
("ignoring magic //go:%s comment "
"before declaration"),
pragma_check[i].name);
}
else if (rec == NULL)
{
if (pragma_check[i].func_ok)
continue;
go_warning_at(location, 0,
("ignoring magic //go:%s comment "
"before function definition"),
pragma_check[i].name);
}
else
{
if (pragma_check[i].method_ok)
continue;
go_warning_at(location, 0,
("ignoring magic //go:%s comment "
"before method definition"),
pragma_check[i].name);
}
pragmas &= ~ pragma_check[i].bit;
}
}
if (is_decl)
{
if (named_object == NULL)
{
// Function declarations with the blank identifier as a name are
// mostly ignored since they cannot be called. We make an object
// for this declaration for type-checking purposes.
if (Gogo::is_sink_name(name))
{
static int count;
char buf[30];
snprintf(buf, sizeof buf, ".$sinkfndecl%d", count);
++count;
name = std::string(buf);
}
if (fntype == NULL
|| (expected_receiver && rec == NULL))
this->gogo_->add_erroneous_name(name);
else
{
named_object = this->gogo_->declare_function(name, fntype,
location);
if (!extern_name.empty()
&& named_object->is_function_declaration())
{
Function_declaration* fd =
named_object->func_declaration_value();
fd->set_asm_name(extern_name);
}
}
}
if (pragmas != 0 && named_object->is_function_declaration())
named_object->func_declaration_value()->set_pragmas(pragmas);
}
else
{
bool hold_is_erroneous_function = this->is_erroneous_function_;
if (fntype == NULL)
{
fntype = Type::make_function_type(NULL, NULL, NULL, location);
this->is_erroneous_function_ = true;
if (!Gogo::is_sink_name(name))
this->gogo_->add_erroneous_name(name);
name = this->gogo_->pack_hidden_name("_", false);
}
named_object = this->gogo_->start_function(name, fntype, true, location);
Location end_loc = this->block();
this->gogo_->finish_function(end_loc);
if (pragmas != 0
&& !this->is_erroneous_function_
&& named_object->is_function())
named_object->func_value()->set_pragmas(pragmas);
this->is_erroneous_function_ = hold_is_erroneous_function;
}
}
// Receiver = Parameters .
Typed_identifier*
Parse::receiver()
{
Location location = this->location();
Typed_identifier_list* til;
if (!this->parameters(&til, NULL))
return NULL;
else if (til == NULL || til->empty())
{
go_error_at(location, "method has no receiver");
return NULL;
}
else if (til->size() > 1)
{
go_error_at(location, "method has multiple receivers");
return NULL;
}
else
return &til->front();
}
// Operand = Literal | QualifiedIdent | MethodExpr | "(" Expression ")" .
// Literal = BasicLit | CompositeLit | FunctionLit .
// BasicLit = int_lit | float_lit | imaginary_lit | char_lit | string_lit .
// If MAY_BE_SINK is true, this operand may be "_".
// If IS_PARENTHESIZED is not NULL, *IS_PARENTHESIZED is set to true
// if the entire expression is in parentheses.
Expression*
Parse::operand(bool may_be_sink, bool* is_parenthesized)
{
const Token* token = this->peek_token();
Expression* ret;
switch (token->classification())
{
case Token::TOKEN_IDENTIFIER:
{
Location location = token->location();
std::string id = token->identifier();
bool is_exported = token->is_identifier_exported();
std::string packed = this->gogo_->pack_hidden_name(id, is_exported);
Named_object* in_function;
Named_object* named_object = this->gogo_->lookup(packed, &in_function);
Package* package = NULL;
if (named_object != NULL && named_object->is_package())
{
if (!this->advance_token()->is_op(OPERATOR_DOT)
|| !this->advance_token()->is_identifier())
{
go_error_at(location, "unexpected reference to package");
return Expression::make_error(location);
}
package = named_object->package_value();
package->note_usage(id);
id = this->peek_token()->identifier();
is_exported = this->peek_token()->is_identifier_exported();
packed = this->gogo_->pack_hidden_name(id, is_exported);
named_object = package->lookup(packed);
location = this->location();
go_assert(in_function == NULL);
}
this->advance_token();
if (named_object != NULL
&& named_object->is_type()
&& !named_object->type_value()->is_visible())
{
go_assert(package != NULL);
go_error_at(location, "invalid reference to hidden type %<%s.%s%>",
Gogo::message_name(package->package_name()).c_str(),
Gogo::message_name(id).c_str());
return Expression::make_error(location);
}
if (named_object == NULL)
{
if (package != NULL)
{
std::string n1 = Gogo::message_name(package->package_name());
std::string n2 = Gogo::message_name(id);
if (!is_exported)
go_error_at(location,
("invalid reference to unexported identifier "
"%<%s.%s%>"),
n1.c_str(), n2.c_str());
else
go_error_at(location,
"reference to undefined identifier %<%s.%s%>",
n1.c_str(), n2.c_str());
return Expression::make_error(location);
}
named_object = this->gogo_->add_unknown_name(packed, location);
}
if (in_function != NULL
&& in_function != this->gogo_->current_function()
&& (named_object->is_variable()
|| named_object->is_result_variable()))
return this->enclosing_var_reference(in_function, named_object,
may_be_sink, location);
switch (named_object->classification())
{
case Named_object::NAMED_OBJECT_CONST:
return Expression::make_const_reference(named_object, location);
case Named_object::NAMED_OBJECT_TYPE:
return Expression::make_type(named_object->type_value(), location);
case Named_object::NAMED_OBJECT_TYPE_DECLARATION:
{
Type* t = Type::make_forward_declaration(named_object);
return Expression::make_type(t, location);
}
case Named_object::NAMED_OBJECT_VAR:
case Named_object::NAMED_OBJECT_RESULT_VAR:
// Any left-hand-side can be a sink, so if this can not be
// a sink, then it must be a use of the variable.
if (!may_be_sink)
this->mark_var_used(named_object);
return Expression::make_var_reference(named_object, location);
case Named_object::NAMED_OBJECT_SINK:
if (may_be_sink)
return Expression::make_sink(location);
else
{
go_error_at(location, "cannot use _ as value");
return Expression::make_error(location);
}
case Named_object::NAMED_OBJECT_FUNC:
case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
return Expression::make_func_reference(named_object, NULL,
location);
case Named_object::NAMED_OBJECT_UNKNOWN:
{
Unknown_expression* ue =
Expression::make_unknown_reference(named_object, location);
if (this->is_erroneous_function_)
ue->set_no_error_message();
return ue;
}
case Named_object::NAMED_OBJECT_ERRONEOUS:
return Expression::make_error(location);
default:
go_unreachable();
}
}
go_unreachable();
case Token::TOKEN_STRING:
ret = Expression::make_string(token->string_value(), token->location());
this->advance_token();
return ret;
case Token::TOKEN_CHARACTER:
ret = Expression::make_character(token->character_value(), NULL,
token->location());
this->advance_token();
return ret;
case Token::TOKEN_INTEGER:
ret = Expression::make_integer_z(token->integer_value(), NULL,
token->location());
this->advance_token();
return ret;
case Token::TOKEN_FLOAT:
ret = Expression::make_float(token->float_value(), NULL,
token->location());
this->advance_token();
return ret;
case Token::TOKEN_IMAGINARY:
{
mpfr_t zero;
mpfr_init_set_ui(zero, 0, GMP_RNDN);
mpc_t val;
mpc_init2(val, mpc_precision);
mpc_set_fr_fr(val, zero, *token->imaginary_value(), MPC_RNDNN);
mpfr_clear(zero);
ret = Expression::make_complex(&val, NULL, token->location());
mpc_clear(val);
this->advance_token();
return ret;
}
case Token::TOKEN_KEYWORD:
switch (token->keyword())
{
case KEYWORD_FUNC:
return this->function_lit();
case KEYWORD_CHAN:
case KEYWORD_INTERFACE:
case KEYWORD_MAP:
case KEYWORD_STRUCT:
{
Location location = token->location();
return Expression::make_type(this->type(), location);
}
default:
break;
}
break;
case Token::TOKEN_OPERATOR:
if (token->is_op(OPERATOR_LPAREN))
{
this->advance_token();
ret = this->expression(PRECEDENCE_NORMAL, may_be_sink, true, NULL,
NULL);
if (!this->peek_token()->is_op(OPERATOR_RPAREN))
go_error_at(this->location(),