Cleanup code around JERRY_UNREACHABLEs (#2342)

`JERRY_UNREACHABLE`s often signal code structure that could be
improved: they can usually either be rewritten to `JERRY_ASSERT`s
or eliminated by restructuring loops, `if`s or `#if`s. Roughly,
the only valid occurences are in default cases of `switch`es. And
even they can often be merged into non-default cases.

Moreover, it is dangerous to write meaningful code after
`JERRY_UNREACHABLE` because it pretends as if there was a way to
recover from an impossible situation.

This patch rewrites/eliminates `JERRY_UNREACHABLE`s where possible
and removes misleading code from after them.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu
This commit is contained in:
Akos Kiss
2018-05-25 07:27:30 +02:00
committed by GitHub
parent acb3e71436
commit 4779451284
24 changed files with 168 additions and 256 deletions
+30 -46
View File
@@ -196,15 +196,12 @@ ecma_gc_mark_property (ecma_property_pair_t *property_pair_p, /**< property pair
}
break;
}
case ECMA_PROPERTY_TYPE_SPECIAL:
{
JERRY_ASSERT (property == ECMA_PROPERTY_TYPE_HASHMAP
|| property == ECMA_PROPERTY_TYPE_DELETED);
break;
}
default:
{
JERRY_UNREACHABLE ();
JERRY_ASSERT (ECMA_PROPERTY_GET_TYPE (property) == ECMA_PROPERTY_TYPE_SPECIAL);
JERRY_ASSERT (property == ECMA_PROPERTY_TYPE_HASHMAP
|| property == ECMA_PROPERTY_TYPE_DELETED);
break;
}
}
@@ -290,14 +287,6 @@ ecma_gc_mark (ecma_object_t *object_p) /**< object to mark from */
switch (ext_object_p->u.pseudo_array.type)
{
case ECMA_PSEUDO_ARRAY_ARGUMENTS:
{
ecma_object_t *lex_env_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_object_t,
ext_object_p->u.pseudo_array.u2.lex_env_cp);
ecma_gc_set_object_visited (lex_env_p);
break;
}
#ifndef CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN
case ECMA_PSEUDO_ARRAY_TYPEDARRAY:
case ECMA_PSEUDO_ARRAY_TYPEDARRAY_WITH_INFO:
@@ -308,7 +297,12 @@ ecma_gc_mark (ecma_object_t *object_p) /**< object to mark from */
#endif /* !CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN */
default:
{
JERRY_UNREACHABLE ();
JERRY_ASSERT (ext_object_p->u.pseudo_array.type == ECMA_PSEUDO_ARRAY_ARGUMENTS);
ecma_object_t *lex_env_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_object_t,
ext_object_p->u.pseudo_array.u2.lex_env_cp);
ecma_gc_set_object_visited (lex_env_p);
break;
}
}
@@ -537,15 +531,6 @@ ecma_gc_free_object (ecma_object_t *object_p) /**< object to free */
switch (ext_object_p->u.class_prop.class_id)
{
/* The undefined id represents an uninitialized class. */
case LIT_MAGIC_STRING_UNDEFINED:
case LIT_MAGIC_STRING_ARGUMENTS_UL:
case LIT_MAGIC_STRING_BOOLEAN_UL:
case LIT_MAGIC_STRING_ERROR_UL:
{
break;
}
case LIT_MAGIC_STRING_STRING_UL:
case LIT_MAGIC_STRING_NUMBER_UL:
{
@@ -615,7 +600,11 @@ ecma_gc_free_object (ecma_object_t *object_p) /**< object to free */
#endif /* !CONFIG_DISABLE_ES2015_PROMISE_BUILTIN */
default:
{
JERRY_UNREACHABLE ();
/* The undefined id represents an uninitialized class. */
JERRY_ASSERT (ext_object_p->u.class_prop.class_id == LIT_MAGIC_STRING_UNDEFINED
|| ext_object_p->u.class_prop.class_id == LIT_MAGIC_STRING_ARGUMENTS_UL
|| ext_object_p->u.class_prop.class_id == LIT_MAGIC_STRING_BOOLEAN_UL
|| ext_object_p->u.class_prop.class_id == LIT_MAGIC_STRING_ERROR_UL);
break;
}
}
@@ -689,8 +678,22 @@ ecma_gc_free_object (ecma_object_t *object_p) /**< object to free */
switch (ext_object_p->u.pseudo_array.type)
{
case ECMA_PSEUDO_ARRAY_ARGUMENTS:
#ifndef CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN
case ECMA_PSEUDO_ARRAY_TYPEDARRAY:
{
ecma_dealloc_extended_object (object_p, sizeof (ecma_extended_object_t));
return;
}
case ECMA_PSEUDO_ARRAY_TYPEDARRAY_WITH_INFO:
{
ecma_dealloc_extended_object (object_p, sizeof (ecma_extended_typedarray_object_t));
return;
}
#endif /* !CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN */
default:
{
JERRY_ASSERT (ext_object_p->u.pseudo_array.type == ECMA_PSEUDO_ARRAY_ARGUMENTS);
ecma_length_t formal_params_number = ext_object_p->u.pseudo_array.u1.length;
ecma_value_t *arg_Literal_p = (ecma_value_t *) (ext_object_p + 1);
@@ -707,26 +710,7 @@ ecma_gc_free_object (ecma_object_t *object_p) /**< object to free */
ecma_dealloc_extended_object (object_p, sizeof (ecma_extended_object_t) + formal_params_size);
return;
}
#ifndef CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN
case ECMA_PSEUDO_ARRAY_TYPEDARRAY:
{
ecma_dealloc_extended_object (object_p, sizeof (ecma_extended_object_t));
return;
}
case ECMA_PSEUDO_ARRAY_TYPEDARRAY_WITH_INFO:
{
ecma_dealloc_extended_object (object_p, sizeof (ecma_extended_typedarray_object_t));
return;
}
#endif /* !CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN */
default:
{
JERRY_UNREACHABLE ();
break;
}
}
JERRY_UNREACHABLE ();
}
if (object_type == ECMA_OBJECT_TYPE_BOUND_FUNCTION)