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Tuple receives indicate whether channel is closed.

Browse source 
From-SVN: r171380
This commit is contained in:
Ian Lance Taylor 2011-03-24 06:01:27 +00:00
parent 4908b0bf1c
commit 3137991dfc
11 changed files with 319 additions and 153 deletions
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2
gcc/go/gofrontend/gogo-tree.cc
View file

@ -3057,7 +3057,7 @@ Gogo::receive_from_channel(tree type_tree, tree channel, bool for_select,
location,
"__go_receive_big",
3,
void_type_node,
boolean_type_node,
ptr_type_node,
channel,
ptr_type_node,

11
gcc/go/gofrontend/gogo.cc
View file

@ -1257,7 +1257,7 @@ Lower_parse_tree::statement(Block* block, size_t* pindex, Statement* sorig)
Statement* s = sorig;
while (true)
{
Statement* snew = s->lower(this->gogo_, block);
Statement* snew = s->lower(this->gogo_, this->function_, block);
if (snew == s)
break;
s = snew;
@ -1305,6 +1305,15 @@ Gogo::lower_parse_tree()
this->traverse(&lower_parse_tree);
}
// Lower a block.
void
Gogo::lower_block(Named_object* function, Block* block)
{
Lower_parse_tree lower_parse_tree(this, function);
block->traverse(&lower_parse_tree);
}
// Lower an expression.
void

4
gcc/go/gofrontend/gogo.h
View file

@ -348,6 +348,10 @@ class Gogo
void
lower_parse_tree();
// Lower all the statements in a block.
void
lower_block(Named_object* function, Block*);
// Lower an expression.
void
lower_expression(Named_object* function, Expression**);

196
gcc/go/gofrontend/parse.cc
View file

@ -4179,10 +4179,12 @@ Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
bool is_send = false;
Expression* channel = NULL;
Expression* val = NULL;
Expression* closed = NULL;
std::string varname;
std::string closedname;
bool is_default = false;
bool got_case = this->comm_case(&is_send, &channel, &val, &varname,
&is_default);
bool got_case = this->comm_case(&is_send, &channel, &val, &closed,
&varname, &closedname, &is_default);
if (this->peek_token()->is_op(OPERATOR_COLON))
this->advance_token();
@ -4191,6 +4193,7 @@ Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
Block* statements = NULL;
Named_object* var = NULL;
Named_object* closedvar = NULL;
if (this->peek_token()->is_op(OPERATOR_SEMICOLON))
this->advance_token();
else if (this->statement_list_may_start_here())
@ -4206,6 +4209,14 @@ Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
var = this->gogo_->add_variable(varname, v);
}
if (!closedname.empty())
{
// FIXME: LOCATION is slightly wrong here.
Variable* v = new Variable(Type::lookup_bool_type(), NULL,
false, false, false, location);
closedvar = this->gogo_->add_variable(closedname, v);
}
this->statement_list();
statements = this->gogo_->finish_block(this->location());
}
@ -4221,7 +4232,8 @@ Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
}
if (got_case)
clauses->add(is_send, channel, val, var, is_default, statements, location);
clauses->add(is_send, channel, val, closed, var, closedvar, is_default,
statements, location);
else if (statements != NULL)
{
// Add the statements to make sure that any names they define
@ -4234,7 +4246,8 @@ Parse::comm_clause(Select_clauses* clauses, bool* saw_default)
bool
Parse::comm_case(bool* is_send, Expression** channel, Expression** val,
std::string* varname, bool* is_default)
Expression** closed, std::string* varname,
std::string* closedname, bool* is_default)
{
const Token* token = this->peek_token();
if (token->is_keyword(KEYWORD_DEFAULT))
@ -4245,7 +4258,8 @@ Parse::comm_case(bool* is_send, Expression** channel, Expression** val,
else if (token->is_keyword(KEYWORD_CASE))
{
this->advance_token();
if (!this->send_or_recv_expr(is_send, channel, val, varname))
if (!this->send_or_recv_stmt(is_send, channel, val, closed, varname,
closedname))
return false;
}
else
@ -4259,74 +4273,160 @@ Parse::comm_case(bool* is_send, Expression** channel, Expression** val,
return true;
}
// RecvExpr = [ Expression ( "=" | ":=" ) ] "<-" Expression .
// RecvStmt = [ Expression [ "," Expression ] ( "=" | ":=" ) ] RecvExpr .
// RecvExpr = Expression .
bool
Parse::send_or_recv_expr(bool* is_send, Expression** channel, Expression** val,
std::string* varname)
Parse::send_or_recv_stmt(bool* is_send, Expression** channel, Expression** val,
Expression** closed, std::string* varname,
std::string* closedname)
{
const Token* token = this->peek_token();
source_location location = token->location();
bool saw_comma = false;
bool closed_is_id = false;
if (token->is_identifier())
{
Gogo* gogo = this->gogo_;
std::string recv_var = token->identifier();
bool is_var_exported = token->is_identifier_exported();
if (!this->advance_token()->is_op(OPERATOR_COLONEQ))
this->unget_token(Token::make_identifier_token(recv_var,
is_var_exported,
location));
else
bool is_rv_exported = token->is_identifier_exported();
source_location recv_var_loc = token->location();
token = this->advance_token();
if (token->is_op(OPERATOR_COLONEQ))
{
// case rv := <-c:
if (!this->advance_token()->is_op(OPERATOR_CHANOP))
{
error_at(this->location(), "expected %<<-%>");
return false;
}
if (recv_var == "_")
{
error_at(recv_var_loc,
"no new variables on left side of %<:=%>");
recv_var = "blank";
}
*is_send = false;
*varname = this->gogo_->pack_hidden_name(recv_var, is_var_exported);
*varname = gogo->pack_hidden_name(recv_var, is_rv_exported);
this->advance_token();
*channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
return true;
}
else if (token->is_op(OPERATOR_COMMA))
{
token = this->advance_token();
if (token->is_identifier())
{
std::string recv_closed = token->identifier();
bool is_rc_exported = token->is_identifier_exported();
source_location recv_closed_loc = token->location();
closed_is_id = true;
token = this->advance_token();
if (token->is_op(OPERATOR_COLONEQ))
{
// case rv, rc := <-c:
if (!this->advance_token()->is_op(OPERATOR_CHANOP))
{
error_at(this->location(), "expected %<<-%>");
return false;
}
if (recv_var == "_" && recv_closed == "_")
{
error_at(recv_var_loc,
"no new variables on left side of %<:=%>");
recv_var = "blank";
}
*is_send = false;
if (recv_var != "_")
*varname = gogo->pack_hidden_name(recv_var,
is_rv_exported);
if (recv_closed != "_")
*closedname = gogo->pack_hidden_name(recv_closed,
is_rc_exported);
this->advance_token();
*channel = this->expression(PRECEDENCE_NORMAL, false, true,
NULL);
return true;
}
this->unget_token(Token::make_identifier_token(recv_closed,
is_rc_exported,
recv_closed_loc));
}
*val = this->id_to_expression(gogo->pack_hidden_name(recv_var,
is_rv_exported),
recv_var_loc);
saw_comma = true;
}
else
this->unget_token(Token::make_identifier_token(recv_var,
is_rv_exported,
recv_var_loc));
}
// If SAW_COMMA is false, then we are looking at the start of the
// send or receive expression. If SAW_COMMA is true, then *VAL is
// set and we just read a comma.
if (!saw_comma && this->peek_token()->is_op(OPERATOR_CHANOP))
{
// case <-c:
*is_send = false;
this->advance_token();
*channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
return true;
}
Expression* e = this->expression(PRECEDENCE_NORMAL, true, true, NULL);
if (this->peek_token()->is_op(OPERATOR_EQ))
{
if (!this->advance_token()->is_op(OPERATOR_CHANOP))
{
error_at(this->location(), "missing %<<-%>");
return false;
}
*is_send = false;
this->advance_token();
*channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
if (saw_comma)
{
// case v, e = <-c:
// *VAL is already set.
if (!e->is_sink_expression())
*closed = e;
}
else
{
// case v = <-c:
if (!e->is_sink_expression())
*val = e;
}
return true;
}
if (saw_comma)
{
if (closed_is_id)
error_at(this->location(), "expected %<=%> or %<:=%>");
else
error_at(this->location(), "expected %<=%>");
return false;
}
if (this->peek_token()->is_op(OPERATOR_CHANOP))
{
*is_send = false;
// case c <- v:
*is_send = true;
*channel = this->verify_not_sink(e);
this->advance_token();
*channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
}
else
{
Expression* left = this->expression(PRECEDENCE_NORMAL, true, true, NULL);
if (this->peek_token()->is_op(OPERATOR_EQ))
{
if (!this->advance_token()->is_op(OPERATOR_CHANOP))
{
error_at(this->location(), "missing %<<-%>");
return false;
}
*is_send = false;
*val = left;
this->advance_token();
*channel = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
}
else if (this->peek_token()->is_op(OPERATOR_CHANOP))
{
*is_send = true;
*channel = this->verify_not_sink(left);
this->advance_token();
*val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
}
else
{
error_at(this->location(), "expected %<<-%> or %<=%>");
return false;
}
*val = this->expression(PRECEDENCE_NORMAL, false, true, NULL);
return true;
}
return true;
error_at(this->location(), "expected %<<-%> or %<=%>");
return false;
}
// ForStat = "for" [ Condition | ForClause | RangeClause ] Block .

6
gcc/go/gofrontend/parse.h
View file

@ -246,8 +246,10 @@ class Parse
void type_switch_case(std::vector<Type*>*, bool*);
void select_stat(const Label*);
void comm_clause(Select_clauses*, bool* saw_default);
bool comm_case(bool*, Expression**, Expression**, std::string*, bool*);
bool send_or_recv_expr(bool*, Expression**, Expression**, std::string*);
bool comm_case(bool*, Expression**, Expression**, Expression**,
std::string*, std::string*, bool*);
bool send_or_recv_stmt(bool*, Expression**, Expression**, Expression**,
std::string*, std::string*);
void for_stat(const Label*);
void for_clause(Expression**, Block**);
void range_clause_decl(const Typed_identifier_list*, Range_clause*);

119
gcc/go/gofrontend/statements.cc
View file

@ -638,7 +638,7 @@ class Assignment_operation_statement : public Statement
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -667,7 +667,8 @@ Assignment_operation_statement::do_traverse(Traverse* traverse)
// statement.
Statement*
Assignment_operation_statement::do_lower(Gogo*, Block* enclosing)
Assignment_operation_statement::do_lower(Gogo*, Named_object*,
Block* enclosing)
{
source_location loc = this->location();
@ -764,7 +765,7 @@ class Tuple_assignment_statement : public Statement
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -791,7 +792,7 @@ Tuple_assignment_statement::do_traverse(Traverse* traverse)
// up into a set of single assignments.
Statement*
Tuple_assignment_statement::do_lower(Gogo*, Block* enclosing)
Tuple_assignment_statement::do_lower(Gogo*, Named_object*, Block* enclosing)
{
source_location loc = this->location();
@ -891,7 +892,7 @@ public:
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -920,7 +921,8 @@ Tuple_map_assignment_statement::do_traverse(Traverse* traverse)
// Lower a tuple map assignment.
Statement*
Tuple_map_assignment_statement::do_lower(Gogo*, Block* enclosing)
Tuple_map_assignment_statement::do_lower(Gogo*, Named_object*,
Block* enclosing)
{
source_location loc = this->location();
@ -1037,7 +1039,7 @@ class Map_assignment_statement : public Statement
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -1066,7 +1068,7 @@ Map_assignment_statement::do_traverse(Traverse* traverse)
// Lower a map assignment to a function call.
Statement*
Map_assignment_statement::do_lower(Gogo*, Block* enclosing)
Map_assignment_statement::do_lower(Gogo*, Named_object*, Block* enclosing)
{
source_location loc = this->location();
@ -1145,11 +1147,11 @@ Statement::make_map_assignment(Expression* map_index,
class Tuple_receive_assignment_statement : public Statement
{
public:
Tuple_receive_assignment_statement(Expression* val, Expression* success,
Tuple_receive_assignment_statement(Expression* val, Expression* closed,
Expression* channel,
source_location location)
: Statement(STATEMENT_TUPLE_RECEIVE_ASSIGNMENT, location),
val_(val), success_(success), channel_(channel)
val_(val), closed_(closed), channel_(channel)
{ }
protected:
@ -1161,7 +1163,7 @@ class Tuple_receive_assignment_statement : public Statement
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -1170,8 +1172,8 @@ class Tuple_receive_assignment_statement : public Statement
private:
// Lvalue which receives the value from the channel.
Expression* val_;
// Lvalue which receives whether the read succeeded or failed.
Expression* success_;
// Lvalue which receives whether the channel is closed.
Expression* closed_;
// The channel on which we receive the value.
Expression* channel_;
};
@ -1182,7 +1184,7 @@ int
Tuple_receive_assignment_statement::do_traverse(Traverse* traverse)
{
if (this->traverse_expression(traverse, &this->val_) == TRAVERSE_EXIT
|| this->traverse_expression(traverse, &this->success_) == TRAVERSE_EXIT)
|| this->traverse_expression(traverse, &this->closed_) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
return this->traverse_expression(traverse, &this->channel_);
}
@ -1190,7 +1192,8 @@ Tuple_receive_assignment_statement::do_traverse(Traverse* traverse)
// Lower to a function call.
Statement*
Tuple_receive_assignment_statement::do_lower(Gogo*, Block* enclosing)
Tuple_receive_assignment_statement::do_lower(Gogo*, Named_object*,
Block* enclosing)
{
source_location loc = this->location();
@ -1212,17 +1215,17 @@ Tuple_receive_assignment_statement::do_lower(Gogo*, Block* enclosing)
// evaluated in the right order.
Move_ordered_evals moe(b);
this->val_->traverse_subexpressions(&moe);
this->success_->traverse_subexpressions(&moe);
this->closed_->traverse_subexpressions(&moe);
// var val_temp ELEMENT_TYPE
Temporary_statement* val_temp =
Statement::make_temporary(channel_type->element_type(), NULL, loc);
b->add_statement(val_temp);
// var success_temp bool
Temporary_statement* success_temp =
// var closed_temp bool
Temporary_statement* closed_temp =
Statement::make_temporary(Type::lookup_bool_type(), NULL, loc);
b->add_statement(success_temp);
b->add_statement(closed_temp);
// func chanrecv2(c chan T, val *T) bool
source_location bloc = BUILTINS_LOCATION;
@ -1240,14 +1243,14 @@ Tuple_receive_assignment_statement::do_lower(Gogo*, Block* enclosing)
Named_object::make_function_declaration("chanrecv2", NULL, fntype, bloc);
chanrecv2->func_declaration_value()->set_asm_name("runtime.chanrecv2");
// success_temp = chanrecv2(channel, &val_temp)
// closed_temp = chanrecv2(channel, &val_temp)
Expression* func = Expression::make_func_reference(chanrecv2, NULL, loc);
Expression_list* params = new Expression_list();
params->push_back(this->channel_);
Expression* ref = Expression::make_temporary_reference(val_temp, loc);
params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc));
Expression* call = Expression::make_call(func, params, false, loc);
ref = Expression::make_temporary_reference(success_temp, loc);
ref = Expression::make_temporary_reference(closed_temp, loc);
Statement* s = Statement::make_assignment(ref, call, loc);
b->add_statement(s);
@ -1256,9 +1259,9 @@ Tuple_receive_assignment_statement::do_lower(Gogo*, Block* enclosing)
s = Statement::make_assignment(this->val_, ref, loc);
b->add_statement(s);
// success = success_temp
ref = Expression::make_temporary_reference(success_temp, loc);
s = Statement::make_assignment(this->success_, ref, loc);
// closed = closed_temp
ref = Expression::make_temporary_reference(closed_temp, loc);
s = Statement::make_assignment(this->closed_, ref, loc);
b->add_statement(s);
return Statement::make_block_statement(b, loc);
@ -1267,11 +1270,11 @@ Tuple_receive_assignment_statement::do_lower(Gogo*, Block* enclosing)
// Make a nonblocking receive statement.
Statement*
Statement::make_tuple_receive_assignment(Expression* val, Expression* success,
Statement::make_tuple_receive_assignment(Expression* val, Expression* closed,
Expression* channel,
source_location location)
{
return new Tuple_receive_assignment_statement(val, success, channel,
return new Tuple_receive_assignment_statement(val, closed, channel,
location);
}
@ -1297,7 +1300,7 @@ class Tuple_type_guard_assignment_statement : public Statement
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -1338,7 +1341,8 @@ Tuple_type_guard_assignment_statement::do_traverse(Traverse* traverse)
// Lower to a function call.
Statement*
Tuple_type_guard_assignment_statement::do_lower(Gogo*, Block* enclosing)
Tuple_type_guard_assignment_statement::do_lower(Gogo*, Named_object*,
Block* enclosing)
{
source_location loc = this->location();
@ -1643,7 +1647,7 @@ class Inc_dec_statement : public Statement
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -1659,7 +1663,7 @@ class Inc_dec_statement : public Statement
// Lower to += or -=.
Statement*
Inc_dec_statement::do_lower(Gogo*, Block*)
Inc_dec_statement::do_lower(Gogo*, Named_object*, Block*)
{
source_location loc = this->location();
@ -2429,7 +2433,7 @@ Return_statement::do_traverse_assignments(Traverse_assignments* tassign)
// panic/recover work correctly.
Statement*
Return_statement::do_lower(Gogo*, Block* enclosing)
Return_statement::do_lower(Gogo*, Named_object*, Block* enclosing)
{
if (this->vals_ == NULL)
return this;
@ -3530,7 +3534,7 @@ Switch_statement::do_traverse(Traverse* traverse)
// of if statements.
Statement*
Switch_statement::do_lower(Gogo*, Block* enclosing)
Switch_statement::do_lower(Gogo*, Named_object*, Block* enclosing)
{
source_location loc = this->location();
@ -3871,7 +3875,7 @@ Type_switch_statement::do_traverse(Traverse* traverse)
// equality testing.
Statement*
Type_switch_statement::do_lower(Gogo*, Block* enclosing)
Type_switch_statement::do_lower(Gogo*, Named_object*, Block* enclosing)
{
const source_location loc = this->location();
@ -4079,6 +4083,11 @@ Select_clauses::Select_clause::traverse(Traverse* traverse)
if (Expression::traverse(&this->val_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
}
if (this->closed_ != NULL)
{
if (Expression::traverse(&this->closed_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
}
}
if (this->statements_ != NULL)
{
@ -4093,7 +4102,8 @@ Select_clauses::Select_clause::traverse(Traverse* traverse)
// receive statements to the clauses.
void
Select_clauses::Select_clause::lower(Block* b)
Select_clauses::Select_clause::lower(Gogo* gogo, Named_object* function,
Block* b)
{
if (this->is_default_)
{
@ -4134,6 +4144,30 @@ Select_clauses::Select_clause::lower(Block* b)
send->set_for_select();
init->add_statement(send);
}
else if (this->closed_ != NULL && !this->closed_->is_sink_expression())
{
gcc_assert(this->var_ == NULL && this->closedvar_ == NULL);
if (this->val_ == NULL)
this->val_ = Expression::make_sink(loc);
Statement* s = Statement::make_tuple_receive_assignment(this->val_,
this->closed_,
ref, loc);
init->add_statement(s);
}
else if (this->closedvar_ != NULL)
{
gcc_assert(this->val_ == NULL);
Expression* val;
if (this->var_ == NULL)
val = Expression::make_sink(loc);
else
val = Expression::make_var_reference(this->var_, loc);
Expression* closed = Expression::make_var_reference(this->closedvar_,
loc);
Statement* s = Statement::make_tuple_receive_assignment(val, closed, ref,
loc);
init->add_statement(s);
}
else
{
Receive_expression* recv = Expression::make_receive(ref, loc);
@ -4151,11 +4185,13 @@ Select_clauses::Select_clause::lower(Block* b)
}
else
{
recv->discarding_value();
init->add_statement(Statement::make_statement(recv));
}
}
// Lower any statements we just created.
gogo->lower_block(function, init);
if (this->statements_ != NULL)
init->add_statement(Statement::make_block_statement(this->statements_,
loc));
@ -4222,12 +4258,12 @@ Select_clauses::traverse(Traverse* traverse)
// receive statements to the clauses.
void
Select_clauses::lower(Block* b)
Select_clauses::lower(Gogo* gogo, Named_object* function, Block* b)
{
for (Clauses::iterator p = this->clauses_.begin();
p != this->clauses_.end();
++p)
p->lower(b);
p->lower(gogo, function, b);
}
// Determine types.
@ -4464,12 +4500,13 @@ Select_statement::break_label()
// explicit statements in the clauses.
Statement*
Select_statement::do_lower(Gogo*, Block* enclosing)
Select_statement::do_lower(Gogo* gogo, Named_object* function,
Block* enclosing)
{
if (this->is_lowered_)
return this;
Block* b = new Block(enclosing, this->location());
this->clauses_->lower(b);
this->clauses_->lower(gogo, function, b);
this->is_lowered_ = true;
b->add_statement(this);
return Statement::make_block_statement(b, this->location());
@ -4521,7 +4558,7 @@ For_statement::do_traverse(Traverse* traverse)
// complex statements make it easier to handle garbage collection.
Statement*
For_statement::do_lower(Gogo*, Block* enclosing)
For_statement::do_lower(Gogo*, Named_object*, Block* enclosing)
{
Statement* s;
source_location loc = this->location();
@ -4652,7 +4689,7 @@ For_range_statement::do_traverse(Traverse* traverse)
// statements.
Statement*
For_range_statement::do_lower(Gogo* gogo, Block* enclosing)
For_range_statement::do_lower(Gogo* gogo, Named_object*, Block* enclosing)
{
Type* range_type = this->range_->type();
if (range_type->points_to() != NULL

89
gcc/go/gofrontend/statements.h
View file

@ -162,7 +162,7 @@ class Statement
// Make an assignment from a nonblocking receive to a pair of
// variables.
static Statement*
make_tuple_receive_assignment(Expression* val, Expression* success,
make_tuple_receive_assignment(Expression* val, Expression* closed,
Expression* channel, source_location);
// Make an assignment from a type guard to a pair of variables.
@ -284,11 +284,11 @@ class Statement
// Lower a statement. This is called immediately after parsing to
// simplify statements for further processing. It returns the same
// Statement or a new one. BLOCK is the block containing this
// statement.
// Statement or a new one. FUNCTION is the function containing this
// statement. BLOCK is the block containing this statement.
Statement*
lower(Gogo* gogo, Block* block)
{ return this->do_lower(gogo, block); }
lower(Gogo* gogo, Named_object* function, Block* block)
{ return this->do_lower(gogo, function, block); }
// Set type information for unnamed constants.
void
@ -381,7 +381,7 @@ class Statement
// Implemented by the child class: lower this statement to a simpler
// one.
virtual Statement*
do_lower(Gogo*, Block*)
do_lower(Gogo*, Named_object*, Block*)
{ return this; }
// Implemented by child class: set type information for unnamed
@ -574,7 +574,7 @@ class Return_statement : public Statement
do_traverse_assignments(Traverse_assignments*);
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
void
do_determine_types();
@ -649,17 +649,22 @@ class Select_clauses
// Add a new clause. IS_SEND is true if this is a send clause,
// false for a receive clause. For a send clause CHANNEL is the
// channel and VAL is the value to send. For a receive clause
// CHANNEL is the channel and VAL is either NULL or a Var_expression
// for the variable to set; if VAL is NULL, VAR may be a variable
// which is initialized with the received value. IS_DEFAULT is true
// if this is the default clause. STATEMENTS is the list of
// statements to execute.
// CHANNEL is the channel, VAL is either NULL or a Var_expression
// for the variable to set, and CLOSED is either NULL or a
// Var_expression to set to whether the channel is closed. If VAL
// is NULL, VAR may be a variable to be initialized with the
// received value, and CLOSEDVAR ma be a variable to be initialized
// with whether the channel is closed. IS_DEFAULT is true if this
// is the default clause. STATEMENTS is the list of statements to
// execute.
void
add(bool is_send, Expression* channel, Expression* val, Named_object* var,
bool is_default, Block* statements, source_location location)
add(bool is_send, Expression* channel, Expression* val, Expression* closed,
Named_object* var, Named_object* closedvar, bool is_default,
Block* statements, source_location location)
{
this->clauses_.push_back(Select_clause(is_send, channel, val, var,
is_default, statements, location));
this->clauses_.push_back(Select_clause(is_send, channel, val, closed, var,
closedvar, is_default, statements,
location));
}
// Traverse the select clauses.
@ -668,7 +673,7 @@ class Select_clauses
// Lower statements.
void
lower(Block*);
lower(Gogo*, Named_object*, Block*);
// Determine types.
void
@ -689,16 +694,18 @@ class Select_clauses
{
public:
Select_clause()
: channel_(NULL), val_(NULL), var_(NULL), statements_(NULL),
is_send_(false), is_default_(false)
: channel_(NULL), val_(NULL), closed_(NULL), var_(NULL),
closedvar_(NULL), statements_(NULL), is_send_(false),
is_default_(false)
{ }
Select_clause(bool is_send, Expression* channel, Expression* val,
Named_object* var, bool is_default, Block* statements,
Expression* closed, Named_object* var,
Named_object* closedvar, bool is_default, Block* statements,
source_location location)
: channel_(channel), val_(val), var_(var), statements_(statements),
location_(location), is_send_(is_send), is_default_(is_default),
is_lowered_(false)
: channel_(channel), val_(val), closed_(closed), var_(var),
closedvar_(closedvar), statements_(statements), location_(location),
is_send_(is_send), is_default_(is_default), is_lowered_(false)
{ gcc_assert(is_default ? channel == NULL : channel != NULL); }
// Traverse the select clause.
@ -707,7 +714,7 @@ class Select_clauses
// Lower statements.
void
lower(Block*);
lower(Gogo*, Named_object*, Block*);
// Determine types.
void
@ -724,20 +731,6 @@ class Select_clauses
channel() const
{ return this->channel_; }
// Return the value. This will return NULL for the default
// clause, or for a receive clause for which no value was given.
Expression*
val() const
{ return this->val_; }
// Return the variable to set when a receive clause is also a
// variable definition (v := <- ch). This will return NULL for
// the default case, or for a send clause, or for a receive clause
// which does not define a variable.
Named_object*
var() const
{ return this->var_; }
// Return true for a send, false for a receive.
bool
is_send() const
@ -768,10 +761,16 @@ class Select_clauses
private:
// The channel.
Expression* channel_;
// The value to send or the variable to set.
// The value to send or the lvalue to receive into.
Expression* val_;
// The variable to initialize, for "case a := <- ch".
// The lvalue to set to whether the channel is closed on a
// receive.
Expression* closed_;
// The variable to initialize, for "case a := <-ch".
Named_object* var_;
// The variable to initialize to whether the channel is closed,
// for "case a, c := <-ch".
Named_object* closedvar_;
// The statements to execute.
Block* statements_;
// The location of this clause.
@ -821,7 +820,7 @@ class Select_statement : public Statement
{ return this->clauses_->traverse(traverse); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
void
do_determine_types()
@ -1008,7 +1007,7 @@ class For_statement : public Statement
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -1066,7 +1065,7 @@ class For_range_statement : public Statement
{ gcc_unreachable(); }
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -1290,7 +1289,7 @@ class Switch_statement : public Statement
do_traverse(Traverse*);
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)
@ -1436,7 +1435,7 @@ class Type_switch_statement : public Statement
do_traverse(Traverse*);
Statement*
do_lower(Gogo*, Block*);
do_lower(Gogo*, Named_object*, Block*);
tree
do_get_tree(Translate_context*)

14
libgo/runtime/chan.goc
View file

@ -12,28 +12,22 @@ typedef struct __go_channel chan;
/* Do a nonblocking channel receive. */
func chanrecv2(c *chan, val *byte) (pres bool) {
func chanrecv2(c *chan, val *byte) (received bool) {
if (c->element_size > 8) {
return __go_receive_nonblocking_big(c, val);
return __go_receive_big(c, val, 0);
} else {
struct __go_receive_nonblocking_small rs;
union {
char b[8];
uint64_t v;
} u;
rs = __go_receive_nonblocking_small (c);
if (!rs.__success) {
__builtin_memset(val, 0, c->element_size);
return 0;
}
u.v = rs.__val;
u.v = __go_receive_small_closed(c, 0, &received);
#ifndef WORDS_BIGENDIAN
__builtin_memcpy(val, u.b, c->element_size);
#else
__builtin_memcpy(val, u.b + 8 - c->element_size,
c->element_size);
#endif
return 1;
return received;
}
}

5
libgo/runtime/channel.h
View file

@ -112,6 +112,9 @@ extern int __go_receive_nonblocking_acquire (struct __go_channel *);
extern uint64_t __go_receive_small (struct __go_channel *, _Bool);
extern uint64_t __go_receive_small_closed (struct __go_channel *, _Bool,
_Bool *);
extern void __go_receive_release (struct __go_channel *);
struct __go_receive_nonblocking_small
@ -123,7 +126,7 @@ struct __go_receive_nonblocking_small
extern struct __go_receive_nonblocking_small
__go_receive_nonblocking_small (struct __go_channel *);
extern void __go_receive_big (struct __go_channel *, void *, _Bool);
extern _Bool __go_receive_big (struct __go_channel *, void *, _Bool);
extern _Bool __go_receive_nonblocking_big (struct __go_channel *, void *);

6
libgo/runtime/go-rec-big.c
View file

@ -9,7 +9,7 @@
#include "go-panic.h"
#include "channel.h"
void
_Bool
__go_receive_big (struct __go_channel *channel, void *val, _Bool for_select)
{
size_t alloc_size;
@ -24,11 +24,13 @@ __go_receive_big (struct __go_channel *channel, void *val, _Bool for_select)
if (!__go_receive_acquire (channel, for_select))
{
__builtin_memset (val, 0, channel->element_size);
return;
return 0;
}
offset = channel->next_fetch * alloc_size;
__builtin_memcpy (val, &channel->data[offset], channel->element_size);
__go_receive_release (channel);
return 1;
}

20
libgo/runtime/go-rec-small.c
View file

@ -263,7 +263,8 @@ __go_unlock_and_notify_selects (struct __go_channel *channel)
/* Receive something 64 bits or smaller on a channel. */
uint64_t
__go_receive_small (struct __go_channel *channel, _Bool for_select)
__go_receive_small_closed (struct __go_channel *channel, _Bool for_select,
_Bool *received)
{
uint64_t ret;
@ -273,11 +274,26 @@ __go_receive_small (struct __go_channel *channel, _Bool for_select)
__go_assert (channel->element_size <= sizeof (uint64_t));
if (!__go_receive_acquire (channel, for_select))
return 0;
{
if (received != NULL)
*received = 0;
return 0;
}
ret = channel->data[channel->next_fetch];
__go_receive_release (channel);
if (received != NULL)
*received = 1;
return ret;
}
/* Called by the compiler. */
uint64_t
__go_receive_small (struct __go_channel *channel, _Bool for_select)
{
return __go_receive_small_closed (channel, for_select, NULL);
}