Mirror/zeek
1
0
Fork 0
mirror of https://github.com/zeek/zeek.git synced 2025-10-13 20:18:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

enum type: don't allow mixing of explicit value and auto-increment.

Browse source 
Updated enum type. New description:

Enum's are supported in .bif and .bro scripts.
An enum in a bif will become available in the event engine and
the policy layer.

It is possible to assign an explicit value to an enum enumerator
element, or the enum type can automatically assign values. However,
the styles cannot be mixed. If automatic assignement is used, the first
element will have a value of 0, the next will have a value of 1, etc.

Enum type variables and identifiers can be formated using the "%s"
format specifier, in which case the symbolic name will be printed.
If the "%d" format specifier is used, the numerical value is
printed.

Example automatic assignment:
    type foo: enum {
        BAR_A,      # value will be 0
        BAR_B,      # value will be 1
        BAR_C,      # value will be 2
    };

Example with explicit assignment:
    type foobar: enum {
        BAR_X = 10,      # value will be 10
        BAR_Y = 23,      # value will be 23
        BAR_Z = 42,      # value will be 42
    };

Enumerator values can only by positive integer literals.
The literals can be specified in (0x....), but not in octal (bro policy
layer limitation). So, do not use 0123 as value in bifs!

Each enumerator value can only be used once per enum (C allows
to use the same value multiple times).

All these restrictions are enforced by the policy script layer and not
the bif compiler!

Enums can be redef'ed, i.e., extended. If the enum is automatic
increment assignment, then the value will continue to increment.
If the enum uses explicit assignment, then the redef need to use
explicit assignments as well.

Example 1::
    redef enum foo += {
        BAR_D,    # value will be 3
        BAR_E,    # value will be 4
        BAR_F,    # value will be 5
    };

Example 2::
    redef enum foobar += {
        BAR_W = 100,
    };
This commit is contained in:
Gregor Maier 2010-12-11 11:57:27 -08:00
parent 72454c230b
commit fdaeea0ea9
3 changed files with 52 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

10
src/parse.y
View file

@ -594,8 +594,8 @@ enum_body_elem:
assert(cur_enum_type);
if ($3->Type()->Tag() != TYPE_COUNT)
error("enumerator is not a count constant");
if ( cur_enum_type->AddName(current_module, $1, $3->InternalUnsigned(), is_export) < 0 )
error("identifier or enumerator value in enumerated type definition already exists");
else
cur_enum_type->AddName(current_module, $1, $3->InternalUnsigned(), is_export);
}
| TOK_ID '=' '-' TOK_CONSTANT
{
@ -609,8 +609,7 @@ enum_body_elem:
{
set_location(@1);
assert(cur_enum_type);
if ( cur_enum_type->AddName(current_module, $1, is_export) < 0 )
error("identifier or enumerator value in enumerated type definition already exists");
cur_enum_type->AddName(current_module, $1, is_export);
}
;
@ -716,9 +715,10 @@ type:
$$ = 0;
}
| TOK_ENUM '{' { parser_new_enum(); } enum_body '}'
| TOK_ENUM '{' { set_location(@1); parser_new_enum(); } enum_body '}'
{
set_location(@1, @5);
$4->UpdateLocationEndInfo(@5);
$$ = $4;
}