(** Context analysis: find declarations of used variables and functions. *)

(** The desugared CiviC code contains [Var], [FunCall] and [Assign] nodes. These
    all use variables or functions identified by a [string] name. The context
    analysis phase links each variable occurrence to its declaration: a
    [VarDec], [Param], [Dim], [GlobalDe[cf]] or [FunDe[cf]].  Since the original
    nodes only have a [string] field to save the declaration, new node types
    have been added which replace the name with a declaration node: [VarUse],
    [FunUse], and [VarLet].

    The whole analysis is done in one traversal. When a declaration node is
    encountered, its name and declaration are added to the currect scope (a
    mutable hash table). When a variable of fuction use is encountered, the name
    and declaration are looked up in the current scope. The scope is duplicated
    when entering a function, and restored when exiting the function, so that
    functions that are not subroutines of each other, do not share inner variable
    definitions. Note that the traversal traverses into functions AFTER it has
    found all declarations in the outer scope of the function, since functions
    can use any function of variable that is defined within the same scope (also
    those defined after the function itself).
    *)

(** Traversal that replaces names with declarations. Exported for use in other
    phases. *)
val analyse_context : Types.node -> Types.node

(** Main phase function, called by {!Main}. Calls {!analyse_context}. *)
val phase : Main.phase_func