Module Runtime

module Runtime: sig .. end

This module provides runtime support for Bisect. Instrumented programs should hence be linked with this module.

At initialization, this module determines the output file for coverage information and creates this file. It also registers a function using Pervasives.at_exit to dump coverage information at program exit.

The default base name is "bisect" in the current directory, but another base name can be specified using the "BISECT_FILE" environment variable. The actual file name is the first non-existing "<base><n>.out" file where <base> is the base name and <n> a natural value padded with zeroes to 4 digits (i.e. "0001", "0002", and so on).

Another environment variable can be used to customize the behaviour of Bisect: "BISECT_SILENT". If this variable is set to "YES" or "ON" (ignoring case) then Bisect will not output any message (its default value is "OFF"). If not silent, Bisect will output a message on the standard error in two situations:

the file cannot be created at program initialization;
the data cannot be written at program termination.

Because of the initialization part of Bisect, one is advised to link this module as one of the first ones of the program. Indeed, when determining the output file for coverage data, the value of the current working directory may be used (if "BISECT_FILE" is not set, or if "BISECT_FILE" designates a relative path). As a consequence, the instrumented program should not modify the current directory before Bisect uses this value, or should modify it purposely.

val init : string -> unit

init file indicates that the file file is part of the application that has been instrumented.

val mark : string -> int -> unit

mark file point indicates that the point identified by the integer point in the file file has been visited. Its associated counter is thus incremented, except if its value is already equal to max_int.