anonymous-functions, their closures, can now be sent over broker.
In order to send an anonymous function the receiver must have parsed
a definition of the functon, but it need not to have been evaluated.
See testing/btest/language/closure-sending.zeek for an example of how
this can be done.
This also sends their closures as well as the closures of regular
functions.
The default value of an ID is now truly the one used to initialize it,
unaltered by any subsequent redefs.
Redefs are now shown separately, along with the expression that
modifies the ID's value.
* origin/topic/timw/171-deprecation-warnings:
GH-171: support warning messages alongside deprecated attributes
Made a minor tweak to give a better error message when using
&deprecated= with something other than a string literal expression.
This allows anonymous functions in Zeek to capture their closures.
they do so by creating a copy of their enclosing frame and joining
that with their own frame.
There is no way to specify what specific items to capture from the
closure like C++, nor is there a nonlocal keyword like Python.
Attemptying to declare a local variable that has already been caught
by the closure will error nicely. At the worst this is an inconvenience
for people who are using lambdas which use the same variable names
as their closures.
As a result of functions copying their enclosing frames there is no
way for a function with a closure to reach back up and modify the
state of the frame that it was created in. This lets functions that
generate functions work as expected. The function can reach back and
modify its copy of the frame that it is captured in though.
Implementation wise this is done by creating two new subclasses in
Zeek. The first is a LambdaExpression which can be thought of as a
function generator. It gathers all of the ingredients for a function
at parse time, and then when evaluated creats a new version of that
function with the frame it is being evaluated in as a closure. The
second subclass is a ClosureFrame. This acts for most intents and
purposes like a regular Frame, but it routes lookups of values to its
closure as needed.
Two parts to this:
* Only allow vector slice assignment in statement contexts, not in
arbitrary assignment expressions. E.g. it's not clear what the
resulting value of `(v[1:2] = vector(1))` is for further expression
chaining. For reference, Python doesn't allow it either.
* Add a subclass of AssignExpr to specialize the behavior for index
slice assignments (because its behavior regarding expression
chaining is different per the previous point) and Unref the RHS
of things like `v[1:2] = vector(1)` after IndexExpr::Assign is
finished inserting it (since no one else takes ownership of it).
Instead of using an Expr subclass, IndexSliceAssignExpr, we could
use a proper Stmt, since that's the only context we currently use it
for, but if we did ever to decide on allowing its use in arbitrary
expression contexts, then I expect we'll need it this way anyway
(just with a different IndexSliceAssignExpr::Eval implementation).
* Minor style/format changes
* Fix a signed/unsigned comparison compiler warning
* Use a non-fatal error for non-integral slice indices so we can
report any further scripting errors instead of stopping the parse
right there
To be more exact: &encrypt, &mergeable, &rotate_interval, &rotate_size
Also removes no longer used redef-able constants:
log_rotate_interval, log_max_size, log_encryption_key
GH-243
* All "Broxygen" usages have been replaced in
code, documentation, filenames, etc.
* Sphinx roles/directives like ":bro:see" are now ":zeek:see"
* The "--broxygen" command-line option is now "--zeexygen"
When 'x' is an integral arithmetic expression, it's now coerced to
yield a signed integer before taking the absolute value of it to
prevent the common issue of unsigned integer overflow/wraparound for
values below zero.
Using a time or interval value/expression for 'x' now also yields a
time or interval, respective, from the |x| operation instead of
a double.
This makes
@if (conditions)
event a(...)
@else
event b(...)
@endif
work, which threw an error in the past. This is useful when event
definition change in newer Bro version and code wants to accept both
kinds of events.
* 'topic/vern/bit-ops' of https://github.com/bro/bro:
documentation clarification for "p1 | p2"
documentation for bitwise operators
document the '|' operator for patterns
test suite for bitwise operators brief NEWS blurb allow for "counter" operands (does anyone still use these?) for one (but not both) of the bitwise operands
bitwise operations for "count" types implemented
Starting branch for supporting bit operations on count's.
The configuration framework consists of three mostly distinct parts:
* option variables
* the config reader
* the script level framework
I will describe the three elements in the following.
Internally, this commit also performs a range of changes to the Input
manager; it marks a lot of functions as const and introduces a new
ValueToVal method (which could in theory replace the already existing
one - it is a bit more powerful).
This also changes SerialTypes to have a subtype for Values, just as
Fields already have it; I think it was mostly an oversight that this was
not introduced from the beginning. This should not necessitate any code
changes for people already using SerialTypes.
option variable
===============
The option keyword allows variables to be specified as run-tine options.
Such variables cannot be changed using normal assignments. Instead, they
can be changed using Option::set. It is possible to "subscribe" to
options and be notified when an option value changes.
Change handlers can also change values before they are applied; this
gives them the opportunity to reject changes. Priorities can be
specified if there are several handlers for one option.
Example script:
option testbool: bool = T;
function option_changed(ID: string, new_value: bool): bool
{
print fmt("Value of %s changed from %s to %s", ID, testbool, new_value);
return new_value;
}
event bro_init()
{
print "Old value", testbool;
Option::set_change_handler("testbool", option_changed);
Option::set("testbool", F);
print "New value", testbool;
}
config reader
=============
The config reader provides a way to read configuration files back into
Bro. Most importantly it automatically converts values to the correct
types. This is important because it is at least inconvenient (and
sometimes near impossible) to perform the necessary type conversions in
Bro scripts themselves. This is especially true for sets/vectors.
Configuration generally look like this:
[option name][tab/spaces][new variable value]
so, for example:
testaddr 2607:f8b0:4005:801::200e
testinterval 60
testtime 1507321987
test_set a b c d erdbeerschnitzel
The reader uses the option name to look up the type that variable has in
the Bro core and automatically converts the value to the correct type.
Example script use:
type Idx: record {
option_name: string;
};
type Val: record {
option_val: string;
};
global currconfig: table[string] of string = table();
event InputConfig::new_value(name: string, source: string, id: string, value: any)
{
print id, value;
}
event bro_init()
{
Input::add_table([$reader=Input::READER_CONFIG, $source="../configfile", $name="configuration", $idx=Idx, $val=Val, $destination=currconfig, $want_record=F]);
}
Script-level config framework
=============================
The script-level framework ties these two features together and makes
them a bit more convenient to use. Configuration files can simply be
specified by placing them into Config::config_files. The framework also
creates a config.log that shows all value changes that took place.
Usage example:
redef Config::config_files += {configfile};
export {
option testbool : bool = F;
}
The file is now monitored for changes; when a change occurs the
respective option values are automatically updated and the value change
is written to config.log.
Scheduling a local event variable resulted in a global lookup instead of
evaluating the local variable. To prevent misunderstandings, this will
trigger an error now.
While scripts are parsed, a warning is raised for each usage of an
identifier marked as &deprecated. This also works for BIFs.
Addresses BIT-924, BIT-757.
When an anonymoys function was defined inside an initialization
context, that context transfered over to the function body and could
lead to spurious error messages.
