package bap-std

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Tries on BIL.

Bil provides two prefix tries trees.

The default one is not normalized and will compare bil statements literally. This means that comparison is sensitive to variable names and immediate values. Depending on your context it may be find or not. For example, two SP variables may compare as different if one of them was obtained from different compilation (and met the other one through some persistent storage, e.g., file on hard disk). Moreover, BIL obtained from different lifters will have different names for the same registers. All this issues are addressed in normalized Trie.

type normalized_bil
val normalize : ?subst:(exp * exp) list -> stmt list -> normalized_bil

normalize ?subst bil normalize BIL. If subst is provided, then substitute each occurrence of the fst expression to the snd expression before the normalization. The effect of normalization is the following:

1. All immediate values are compared equal 2. All variables are compared nominally 3. BIL is simplified to reduce the syntactic differences (but the comparison is still syntactic, and (x + 2) will be compared differently to (2 + x).

module Normalized : Trie.S with type key = normalized_bil
include Trie.S with type key = stmt list
type 'a t

trie can store arbitrary data

val t_of_sexp : (Ppx_sexp_conv_lib.Sexp.t -> 'a) -> Ppx_sexp_conv_lib.Sexp.t -> 'a t
val sexp_of_t : ('a -> Ppx_sexp_conv_lib.Sexp.t) -> 'a t -> Ppx_sexp_conv_lib.Sexp.t
type key = stmt list

a key type that is used to lookup data

val create : unit -> 'a t

create () creates new empty trie

val add : 'a t -> key:key -> data:'a -> unit

add trie ~key ~data associates data with key. If trie already has some value associated with key, then the value will be overwritten (rebound)

val change : 'a t -> key -> ('a option -> 'a option) -> unit

change trie key f if trie has data associated with key then f will be called with Some data, otherwise it will be called with None. If f returns None then there will be no data associated with key, if f returns Some thing, then thing will be associated with key

val find : 'a t -> key -> 'a option

find trie key finds data associated with key

val walk : 'a t -> key -> init:'b -> f:('b -> 'a option -> 'b) -> 'b

walk trie key ~init ~f walks down the tree starting from the root and ending with the last token of the key. Function f is fold over values associated with all substrings of the key, starting from a zero substring.

val remove : 'a t -> key -> unit

remove trie key removes value bound with key if any.

val longest_match : 'a t -> key -> (int * 'a) option

longest_match trie key find a value associated with a longest substring of key. Returns a pair - a length of matched key and the value, associated with that key.

val length : 'a t -> int

length trie returns the number of values in trie

pp pp_val creates a printer for a given value printer pp_val. Example:

let int_trie = String.Trie.pp pp_int

will create a printer for a String.Trie that is populated by integers.

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