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riscv-gcc-1
Commit b1b3aec1 by Ian Lance Taylor
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compiler: Give an error if a variable is defined but not used. 

From-SVN: r183458
parent 8bae34da
Showing with 169 additions and 22 deletions
gcc/go/gofrontend/expressions.cc
......@@ -1472,6 +1472,7 @@ Unknown_expression::do_lower(Gogo*, Named_object*, Statement_inserter*, int)
real->message_name().c_str());
return Expression::make_error(location);
case Named_object::NAMED_OBJECT_VAR:
real->var_value()->set_is_used();
return Expression::make_var_reference(real, location);
case Named_object::NAMED_OBJECT_FUNC:
case Named_object::NAMED_OBJECT_FUNC_DECLARATION:
......
gcc/go/gofrontend/gogo.cc
......@@ -1036,6 +1036,23 @@ Gogo::add_named_object(Named_object* no)
this->current_bindings()->add_named_object(no);
}
// Mark all local variables used. This is used when some types of
// parse error occur.
void
Gogo::mark_locals_used()
{
for (Open_functions::iterator pf = this->functions_.begin();
pf != this->functions_.end();
++pf)
{
for (std::vector<Block*>::iterator pb = pf->blocks.begin();
pb != pf->blocks.end();
++pb)
(*pb)->bindings()->mark_locals_used();
}
}
// Record that we've seen an interface type.
void
......@@ -1731,6 +1748,15 @@ Check_types_traverse::variable(Named_object* named_object)
reason.c_str());
var->clear_init();
}
else if (!var->is_used()
&& !var->is_global()
&& !var->is_parameter()
&& !var->is_receiver()
&& !var->type()->is_error()
&& (init == NULL || !init->is_error_expression())
&& !Lex::is_invalid_identifier(named_object->name()))
error_at(var->location(), "%qs declared and not used",
named_object->message_name().c_str());
}
return TRAVERSE_CONTINUE;
}
......@@ -2973,6 +2999,7 @@ Function::closure_var()
Type* struct_type = Type::make_struct_type(sfl, loc);
Variable* var = new Variable(Type::make_pointer_type(struct_type),
NULL, false, true, false, loc);
var->set_is_used();
this->closure_var_ = Named_object::make_variable("closure", NULL, var);
// Note that the new variable is not in any binding contour.
}
......@@ -3693,7 +3720,7 @@ Variable::Variable(Type* type, Expression* init, bool is_global,
Location location)
: type_(type), init_(init), preinit_(NULL), location_(location),
backend_(NULL), is_global_(is_global), is_parameter_(is_parameter),
is_receiver_(is_receiver), is_varargs_parameter_(false),
is_receiver_(is_receiver), is_varargs_parameter_(false), is_used_(false),
is_address_taken_(false), is_non_escaping_address_taken_(false),
seen_(false), init_is_lowered_(false), type_from_init_tuple_(false),
type_from_range_index_(false), type_from_range_value_(false),
......@@ -4877,6 +4904,19 @@ Bindings::define_type(Named_object* no, Named_type* type)
this->named_objects_.push_back(no);
}
// Mark all local variables as used. This is used for some types of
// parse error.
void
Bindings::mark_locals_used()
{
for (std::vector<Named_object*>::iterator p = this->named_objects_.begin();
p != this->named_objects_.end();
++p)
if ((*p)->is_variable())
(*p)->var_value()->set_is_used();
}
// Traverse bindings.
int
......
gcc/go/gofrontend/gogo.h
......@@ -344,6 +344,11 @@ class Gogo
void
add_named_object(Named_object*);
// Mark all local variables in current bindings as used. This is
// used when there is a parse error to avoid useless errors.
void
mark_locals_used();
// Return a name to use for a thunk function. A thunk function is
// one we create during the compilation, for a go statement or a
// defer statement or a method expression.
......@@ -1232,6 +1237,16 @@ class Variable
this->is_varargs_parameter_ = true;
}
// Return whether the variable has been used.
bool
is_used() const
{ return this->is_used_; }
// Mark that the variable has been used.
void
set_is_used()
{ this->is_used_ = true; }
// Clear the initial value; used for error handling.
void
clear_init()
......@@ -1368,6 +1383,8 @@ class Variable
bool is_receiver_ : 1;
// Whether this is the varargs parameter of a function.
bool is_varargs_parameter_ : 1;
// Whether this variable is ever referenced.
bool is_used_ : 1;
// Whether something takes the address of this variable. For a
// local variable this implies that the variable has to be on the
// heap.
......@@ -2124,6 +2141,11 @@ class Bindings
void
remove_binding(Named_object*);
// Mark all variables as used. This is used for some types of parse
// error.
void
mark_locals_used();
// Traverse the tree. See the Traverse class.
int
traverse(Traverse*, bool is_global);
......
gcc/go/gofrontend/lex.cc
......@@ -866,6 +866,7 @@ Lex::gather_identifier()
this->lineoff_ = p - this->linebuf_;
const char* pnext = this->advance_one_utf8_char(p, &ci,
&issued_error);
bool is_invalid = false;
if (!Lex::is_unicode_letter(ci) && !Lex::is_unicode_digit(ci))
{
// There is no valid place for a non-ASCII character
......@@ -876,6 +877,7 @@ Lex::gather_identifier()
error_at(this->location(),
"invalid character 0x%x in identifier",
ci);
is_invalid = true;
}
if (is_first)
{
......@@ -887,6 +889,8 @@ Lex::gather_identifier()
buf.assign(pstart, p - pstart);
has_non_ascii_char = true;
}
if (is_invalid && !Lex::is_invalid_identifier(buf))
buf.append("$INVALID$");
p = pnext;
char ubuf[50];
// This assumes that all assemblers can handle an identifier
......@@ -2312,3 +2316,13 @@ Lex::is_exported_name(const std::string& name)
return Lex::is_unicode_uppercase(ci);
}
}
// Return whether the identifier NAME contains an invalid character.
// This is based on how we handle invalid characters in
// gather_identifier.
bool
Lex::is_invalid_identifier(const std::string& name)
{
return name.find("$INVALID$") != std::string::npos;
}
gcc/go/gofrontend/lex.h
......@@ -349,6 +349,13 @@ class Lex
static bool
is_exported_name(const std::string& name);
// Return whether the identifier NAME is invalid. When we see an
// invalid character we still build an identifier, but we use a
// magic string to indicate that the identifier is invalid. We then
// use this to avoid knockon errors.
static bool
is_invalid_identifier(const std::string& name);
// A helper function. Append V to STR. IS_CHARACTER is true if V
// is a Unicode character which should be converted into UTF-8,
// false if it is a byte value to be appended directly. The
......
gcc/go/gofrontend/parse.cc
......@@ -49,7 +49,8 @@ Parse::Parse(Lex* lex, Gogo* gogo)
break_stack_(NULL),
continue_stack_(NULL),
iota_(0),
enclosing_vars_()
enclosing_vars_(),
type_switch_vars_()
{
}
......@@ -539,6 +540,7 @@ Parse::field_decl(Struct_field_list* sfl)
else
{
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())
......@@ -554,6 +556,7 @@ Parse::field_decl(Struct_field_list* sfl)
if (!this->peek_token()->is_identifier())
{
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())
......@@ -1123,6 +1126,8 @@ Parse::block()
if (!token->is_eof() || !saw_errors())
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();
......@@ -1249,6 +1254,7 @@ Parse::method_spec(Typed_identifier_list* methods)
"name list not allowed in interface type");
else
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)
......@@ -1498,6 +1504,7 @@ Parse::type_spec(void*)
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();
......@@ -1558,6 +1565,7 @@ Parse::var_spec(void*)
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())
......@@ -1894,6 +1902,7 @@ Parse::init_var(const Typed_identifier& tid, Type* type, Expression* init,
// 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);
......@@ -2188,6 +2197,7 @@ Parse::receiver()
if (!token->is_identifier())
{
error_at(this->location(), "method has no receiver");
this->gogo_->mark_locals_used();
while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
token = this->advance_token();
if (!token->is_eof())
......@@ -2227,6 +2237,7 @@ Parse::receiver()
if (!token->is_identifier())
{
error_at(this->location(), "expected receiver name or type");
this->gogo_->mark_locals_used();
int c = token->is_op(OPERATOR_LPAREN) ? 1 : 0;
while (!token->is_eof())
{
......@@ -2258,6 +2269,7 @@ Parse::receiver()
error_at(this->location(), "method has multiple receivers");
else
error_at(this->location(), "expected %<)%>");
this->gogo_->mark_locals_used();
while (!token->is_eof() && !token->is_op(OPERATOR_RPAREN))
token = this->advance_token();
if (!token->is_eof())
......@@ -2365,6 +2377,7 @@ Parse::operand(bool may_be_sink)
}
case Named_object::NAMED_OBJECT_VAR:
case Named_object::NAMED_OBJECT_RESULT_VAR:
this->mark_var_used(named_object);
return Expression::make_var_reference(named_object, location);
case Named_object::NAMED_OBJECT_SINK:
if (may_be_sink)
......@@ -2477,6 +2490,8 @@ Parse::enclosing_var_reference(Named_object* in_function, Named_object* var,
{
go_assert(var->is_variable() || var->is_result_variable());
this->mark_var_used(var);
Named_object* this_function = this->gogo_->current_function();
Named_object* closure = this_function->func_value()->closure_var();
......@@ -2648,6 +2663,7 @@ Parse::composite_lit(Type* type, int depth, Location location)
{
error_at(this->location(), "expected %<,%> or %<}%>");
this->gogo_->mark_locals_used();
int depth = 0;
while (!token->is_eof()
&& (depth > 0 || !token->is_op(OPERATOR_RCURLY)))
......@@ -3019,6 +3035,7 @@ Parse::id_to_expression(const std::string& name, Location location)
return Expression::make_const_reference(named_object, location);
case Named_object::NAMED_OBJECT_VAR:
case Named_object::NAMED_OBJECT_RESULT_VAR:
this->mark_var_used(named_object);
return Expression::make_var_reference(named_object, location);
case Named_object::NAMED_OBJECT_SINK:
return Expression::make_sink(location);
......@@ -3534,6 +3551,7 @@ Parse::simple_stat(bool may_be_composite_lit, bool* return_exp,
{
if (!exp->is_error_expression())
error_at(token->location(), "non-name on left side of %<:=%>");
this->gogo_->mark_locals_used();
while (!token->is_op(OPERATOR_SEMICOLON)
&& !token->is_eof())
token = this->advance_token();
......@@ -4287,7 +4305,15 @@ Parse::type_case_clause(Named_object* switch_no, Type_case_clauses* clauses,
Variable* v = new Variable(type, init, false, false, false,
location);
v->set_is_type_switch_var();
this->gogo_->add_variable(switch_no->name(), v);
Named_object* no = this->gogo_->add_variable(switch_no->name(), v);
// We don't want to issue an error if the compiler
// introduced special variable is not used. Instead we want
// to issue an error if the variable defined by the switch
// is not used. That is handled via type_switch_vars_ and
// Parse::mark_var_used.
v->set_is_used();
this->type_switch_vars_[no] = switch_no;
}
this->statement_list();
statements = this->gogo_->finish_block(this->location());
......@@ -4343,6 +4369,7 @@ Parse::type_switch_case(std::vector<Type*>* types, bool* is_default)
types->push_back(t);
else
{
this->gogo_->mark_locals_used();
token = this->peek_token();
while (!token->is_op(OPERATOR_COLON)
&& !token->is_op(OPERATOR_COMMA)
......@@ -5209,6 +5236,7 @@ Parse::program()
else
{
error_at(this->location(), "expected declaration");
this->gogo_->mark_locals_used();
do
this->advance_token();
while (!this->peek_token()->is_eof()
......@@ -5267,6 +5295,7 @@ Parse::increment_iota()
bool
Parse::skip_past_error(Operator op)
{
this->gogo_->mark_locals_used();
const Token* token = this->peek_token();
while (!token->is_op(op))
{
......@@ -5294,3 +5323,22 @@ Parse::verify_not_sink(Expression* expr)
}
return expr;
}
// Mark a variable as used.
void
Parse::mark_var_used(Named_object* no)
{
if (no->is_variable())
{
no->var_value()->set_is_used();
// When a type switch uses := to define a variable, then for
// each case with a single type we introduce a new variable with
// the appropriate type. When we do, if the newly introduced
// variable is used, then the type switch variable is used.
Type_switch_vars::iterator p = this->type_switch_vars_.find(no);
if (p != this->type_switch_vars_.end())
p->second->var_value()->set_is_used();
}
}
gcc/go/gofrontend/parse.h
......@@ -155,6 +155,11 @@ class Parse
// break or continue statement with no label.
typedef std::vector<std::pair<Statement*, Label*> > Bc_stack;
// Map from type switch variables to the variables they mask, so
// that a use of the type switch variable can become a use of the
// real variable.
typedef Unordered_map(Named_object*, Named_object*) Type_switch_vars;
// Parser nonterminals.
void identifier_list(Typed_identifier_list*);
Expression_list* expression_list(Expression*, bool may_be_sink);
......@@ -288,6 +293,10 @@ class Parse
Statement*
find_bc_statement(const Bc_stack*, const std::string&) const;
// Mark a variable as used.
void
mark_var_used(Named_object*);
// The lexer output we are parsing.
Lex* lex_;
// The current token.
......@@ -307,6 +316,8 @@ class Parse
// References from the local function to variables defined in
// enclosing functions.
Enclosing_vars enclosing_vars_;
// Map from type switch variables to real variables.
Type_switch_vars type_switch_vars_;
};
......
gcc/testsuite/go.test/test/blank1.go
......@@ -9,4 +9,5 @@ package _ // ERROR "invalid package name _"
func main() {
_() // ERROR "cannot use _ as value"
x := _+1 // ERROR "cannot use _ as value"
_ = x
}
gcc/testsuite/go.test/test/fixedbugs/bug014.go
......@@ -11,4 +11,5 @@ func main() {
var c01 uint8 = '\07'; // ERROR "oct|char"
var cx0 uint8 = '\x0'; // ERROR "hex|char"
var cx1 uint8 = '\x'; // ERROR "hex|char"
_, _, _, _ = c00, c01, cx0, cx1
}
gcc/testsuite/go.test/test/fixedbugs/bug108.go
......@@ -7,4 +7,5 @@
package main
func f() {
v := 1 << 1025; // ERROR "overflow|stupid shift"
_ = v
}
gcc/testsuite/go.test/test/fixedbugs/bug141.go
......@@ -20,7 +20,7 @@ type Getter interface {
func f1(p Empty) {
switch x := p.(type) {
default: println("failed to match interface"); os.Exit(1);
default: println("failed to match interface", x); os.Exit(1);
case Getter: break;
}
......
gcc/testsuite/go.test/test/fixedbugs/bug175.go
......@@ -10,5 +10,5 @@ func f() (int, bool) { return 0, true }
func main() {
x, y := f(), 2; // ERROR "multi"
_, _ = x, y
}
gcc/testsuite/go.test/test/fixedbugs/bug200.go
......@@ -12,7 +12,7 @@ func main() {
// and worse, compiled the wrong code
// for one of them.
var x interface{};
switch v := x.(type) {
switch x.(type) {
case func(int):
case func(f int): // ERROR "duplicate"
}
......
gcc/testsuite/go.test/test/fixedbugs/bug213.go
......@@ -7,7 +7,7 @@
package main
func main() {
var v interface{} = 0;
switch x := v.(type) {
switch v.(type) {
case int:
fallthrough; // ERROR "fallthrough"
default:
......
gcc/testsuite/go.test/test/fixedbugs/bug248.dir/bug2.go
......@@ -80,7 +80,7 @@ func main() {
case 2:
i = 3.14
}
switch k := i.(type) {
switch i.(type) {
case p0.T:
if j != 0 {
println("type switch p0.T")
......
gcc/testsuite/go.test/test/fixedbugs/bug309.go
......@@ -15,5 +15,7 @@ func foo(t interface{}, c chan int) {
case <-c:
// bug was: internal compiler error: var without type, init: v
}
default:
_ = v
}
}
gcc/testsuite/go.test/test/fixedbugs/bug363.go
......@@ -17,5 +17,5 @@ func main() {
println(b)
var c int64 = (1<<i) + 4.0 // ok - it's all int64
println(b)
println(c)
}
gcc/testsuite/go.test/test/func4.go
......@@ -11,4 +11,5 @@ var notmain func()
func main() {
var x = &main // ERROR "address of|invalid"
main = notmain // ERROR "assign to|invalid"
_ = x
}
gcc/testsuite/go.test/test/indirect1.go
......@@ -65,4 +65,5 @@ func f() {
cap(b2)+ // ERROR "illegal|invalid|must be"
cap(b3)+
cap(b4) // ERROR "illegal|invalid|must be"
_ = x
}
libgo/go/io/ioutil/ioutil_test.go
......@@ -71,13 +71,13 @@ func TestReadDir(t *testing.T) {
t.Fatalf("ReadDir %s: error expected, none found", dirname)
}
/* Does not work in gccgo testing environment.
dirname = ".."
list, err := ReadDir(dirname)
if err != nil {
t.Fatalf("ReadDir %s: %v", dirname, err)
}
/* Does not work in gccgo testing environment.
foundFile := false
foundSubDir := false
for _, dir := range list {
......@@ -94,5 +94,5 @@ func TestReadDir(t *testing.T) {
if !foundSubDir {
t.Fatalf("ReadDir %s: ioutil directory not found", dirname)
}
*/
*/
}
libgo/go/reflect/type.go
......@@ -243,7 +243,7 @@ type commonType struct {
align int8
fieldAlign uint8
size uintptr
hash uint32
hash uint32
hashfn func(unsafe.Pointer, uintptr)
equalfn func(unsafe.Pointer, unsafe.Pointer, uintptr)
string *string
......@@ -464,7 +464,7 @@ func (t *uncommonType) Method(i int) (m Method) {
m.Type = mt.toType()
x := new(unsafe.Pointer)
*x = p.tfn
m.Func = Value{mt, unsafe.Pointer(x), fl|flagIndir}
m.Func = Value{mt, unsafe.Pointer(x), fl | flagIndir}
m.Index = i
return
}
......@@ -999,10 +999,8 @@ func (ct *commonType) ptrTo() *commonType {
return &p.commonType
}
rt := (*runtime.Type)(unsafe.Pointer(ct))
rp := new(runtime.PtrType)
// initialize p using *byte's ptrType as a prototype.
// have to do assignment as ptrType, not runtime.PtrType,
// in order to write to unexported fields.
......
libgo/go/reflect/value.go
......@@ -215,8 +215,8 @@ type emptyInterface struct {
type nonEmptyInterface struct {
// see ../runtime/iface.c:/Itab
itab *struct {
typ *runtime.Type // dynamic concrete type
fun [100000]unsafe.Pointer // method table
typ *runtime.Type // dynamic concrete type
fun [100000]unsafe.Pointer // method table
}
word iword
}
......@@ -448,7 +448,6 @@ func (v Value) call(method string, in []Value) []Value {
nin++
}
params := make([]unsafe.Pointer, nin)
delta := 0
off := 0
if v.flag&flagMethod != 0 {
// Hard-wired first argument.
......@@ -517,7 +516,7 @@ func isMethod(t *commonType) bool {
params++
} else if c == ')' {
parens--
} else if parens == 0 && c == ' ' && s[i + 1] != '(' && !sawRet {
} else if parens == 0 && c == ' ' && s[i+1] != '(' && !sawRet {
params++
sawRet = true
}
......@@ -1627,7 +1626,7 @@ func MakeChan(typ Type, buffer int) Value {
panic("reflect.MakeChan: unidirectional channel type")
}
ch := makechan(typ.runtimeType(), uint32(buffer))
return Value{typ.common(), unsafe.Pointer(ch), flagIndir | (flag(Chan)<<flagKindShift)}
return Value{typ.common(), unsafe.Pointer(ch), flagIndir | (flag(Chan) << flagKindShift)}
}
// MakeMap creates a new map of the specified type.
......@@ -1636,7 +1635,7 @@ func MakeMap(typ Type) Value {
panic("reflect.MakeMap of non-map type")
}
m := makemap(typ.runtimeType())
return Value{typ.common(), unsafe.Pointer(m), flagIndir | (flag(Map)<<flagKindShift)}
return Value{typ.common(), unsafe.Pointer(m), flagIndir | (flag(Map) << flagKindShift)}
}
// Indirect returns the value that v points to.
......
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