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Avoid endless loop on array with recursive length.

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From-SVN: r168223
This commit is contained in:
Ian Lance Taylor 2010-12-24 01:26:14 +00:00
parent 3746f0c781
commit ab9d6dcfbe
1 changed files with 52 additions and 6 deletions
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58
gcc/go/gofrontend/expressions.cc
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@ -6463,6 +6463,9 @@ class Builtin_call_expression : public Call_expression
Gogo* gogo_;
// The builtin function being called.
Builtin_function_code code_;
// Used to stop endless loops when the length of an array uses len
// or cap of the array itself.
mutable bool seen_;
};
Builtin_call_expression::Builtin_call_expression(Gogo* gogo,
@ -6471,7 +6474,7 @@ Builtin_call_expression::Builtin_call_expression(Gogo* gogo,
bool is_varargs,
source_location location)
: Call_expression(fn, args, is_varargs, location),
gogo_(gogo), code_(BUILTIN_INVALID)
gogo_(gogo), code_(BUILTIN_INVALID), seen_(false)
{
Func_expression* fnexp = this->fn()->func_expression();
gcc_assert(fnexp != NULL);
@ -6781,6 +6784,9 @@ Builtin_call_expression::do_is_constant() const
case BUILTIN_LEN:
case BUILTIN_CAP:
{
if (this->seen_)
return false;
Expression* arg = this->one_arg();
if (arg == NULL)
return false;
@ -6793,10 +6799,15 @@ Builtin_call_expression::do_is_constant() const
if (arg_type->array_type() != NULL
&& arg_type->array_type()->length() != NULL)
return arg_type->array_type()->length()->is_constant();
return true;
if (this->code_ == BUILTIN_LEN && arg_type->is_string_type())
return arg->is_constant();
{
this->seen_ = true;
bool ret = arg->is_constant();
this->seen_ = false;
return ret;
}
}
break;
@ -6868,8 +6879,13 @@ Builtin_call_expression::do_integer_constant_value(bool iota_is_constant,
if (arg_type->array_type() != NULL
&& arg_type->array_type()->length() != NULL)
{
if (this->seen_)
return false;
Expression* e = arg_type->array_type()->length();
if (e->integer_constant_value(iota_is_constant, val, ptype))
this->seen_ = true;
bool r = e->integer_constant_value(iota_is_constant, val, ptype);
this->seen_ = false;
if (r)
{
*ptype = Type::lookup_integer_type("int");
return true;
@ -7484,7 +7500,18 @@ Builtin_call_expression::do_get_tree(Translate_context* context)
gcc_assert(args != NULL && args->size() == 1);
Expression* arg = *args->begin();
Type* arg_type = arg->type();
if (this->seen_)
{
gcc_assert(saw_errors());
return error_mark_node;
}
this->seen_ = true;
tree arg_tree = arg->get_tree(context);
this->seen_ = false;
if (arg_tree == error_mark_node)
return error_mark_node;
@ -7503,7 +7530,16 @@ Builtin_call_expression::do_get_tree(Translate_context* context)
if (arg_type->is_string_type())
val_tree = String_type::length_tree(gogo, arg_tree);
else if (arg_type->array_type() != NULL)
val_tree = arg_type->array_type()->length_tree(gogo, arg_tree);
{
if (this->seen_)
{
gcc_assert(saw_errors());
return error_mark_node;
}
this->seen_ = true;
val_tree = arg_type->array_type()->length_tree(gogo, arg_tree);
this->seen_ = false;
}
else if (arg_type->map_type() != NULL)
{
static tree map_len_fndecl;
@ -7532,7 +7568,17 @@ Builtin_call_expression::do_get_tree(Translate_context* context)
else
{
if (arg_type->array_type() != NULL)
val_tree = arg_type->array_type()->capacity_tree(gogo, arg_tree);
{
if (this->seen_)
{
gcc_assert(saw_errors());
return error_mark_node;
}
this->seen_ = true;
val_tree = arg_type->array_type()->capacity_tree(gogo,
arg_tree);
this->seen_ = false;
}
else if (arg_type->channel_type() != NULL)
{
static tree chan_cap_fndecl;