(** 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 occurrence of this node to a 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 phase traverses into functions, but first finds declarations in the
    entire outer scope of the function, since functions can use any function of
    variable that is defined within the same scope.

    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 vairable 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. *)

(** 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