A CIL Tutorial - Department of Computer Science - ETH Zürich

CHAPTER 12. COMMENTS 106
adjacent to the given source location. The indexes are into the the array returned as the second
element of the return value.
let commentsAdjacent (cca : comment array) (l : location)
: int list × comment array =
if l = locUnknown then [ ], cca else
let cca = prepareCommentArray cca l.file in
(cca | > array bin search comment compare (comment of cilloc l)), cca
The function commentsBetween returns a list of indexes into the array returned as the second
element of the return value. The indexes indicate the comments lying between source locations l1
and l2. If the exact location is not in the comments array, the binary search function returns the
two closest elements. Therefore commentsBetween returns the highest of the lower bounds, and the
smallest of the upper bounds, so that only the indexes for the comments between the two locations
are returned.
let commentsBetween (cca : comment array) (l1 : location) (l2 : location)
: int list × comment array
=
if l1 = locUnknown then commentsAdjacent cca l2 else
if l1.file ≠ l2.file then commentsAdjacent cca l2 else begin
let cca = prepareCommentArray cca l1.file in
let ll = array bin search comment compare (comment of cilloc l1) cca in
let hl = array bin search comment compare (comment of cilloc l2) cca in
let l, h =
match ll, hl with
| ([l] | [ ; l]), h :: → l, h
| → E.s(E.bug "bad result from array bin search")
in
(Array.init (h − l + 1) (fun i → i + l) | > Array.to list), cca
end
The function markComment searches a comment array for an exact source location, and marks the
third element of the tuple for that location as true, indicating in this example that the comment
has been printed by printComments.
let markComment (l : A.cabsloc) (cca : comment array) : unit =
Array.iteri (fun i (l', s, b) →
if compare l l' = 0 then cca.(i) ← (l', s,true)
) cca
The function printComments prints the comments from the array cca' indicated by the indexes in
il and marks the comments as having been printed in cca. The location l is used to indicate the
source location being inspected by an instance of the commentVisitorClass that triggered the call
to printComments.