Official release 4.14.0
Module type
Class type
Library ocamlcommon
Module Cmt_format

The layout of a cmt file is as follows: <cmt> := {<cmi>} <cmt magic> {cmt infos} {<source info>} where <cmi> is the cmi file format: <cmi> := <cmi magic> <cmi info>. More precisely, the optional <cmi> part must be present if and only if the file is:

  • a cmti, or
  • a cmt, for a ml file which has no corresponding mli (hence no corresponding cmti).

Thus, we provide a common reading function for cmi and cmt(i) files which returns an option for each of the three parts: cmi info, cmt info, source info.

type binary_annots =
| Packed of Types.signature * string list
| Implementation of Typedtree.structure
| Interface of Typedtree.signature
| Partial_implementation of binary_part array
| Partial_interface of binary_part array
and binary_part =
| Partial_structure of Typedtree.structure
| Partial_structure_item of Typedtree.structure_item
| Partial_expression of Typedtree.expression
| Partial_pattern : 'k Typedtree.pattern_category * 'k Typedtree.general_pattern -> binary_part
| Partial_class_expr of Typedtree.class_expr
| Partial_signature of Typedtree.signature
| Partial_signature_item of Typedtree.signature_item
| Partial_module_type of Typedtree.module_type
type cmt_infos = {
cmt_modname : Misc.modname;
cmt_annots : binary_annots;
cmt_value_dependencies : (Types.value_description * Types.value_description) list;
cmt_comments : (string * Location.t) list;
cmt_args : string array;
cmt_sourcefile : string option;
cmt_builddir : string;
cmt_loadpath : string list;
cmt_source_digest : string option;
cmt_initial_env : Env.t;
cmt_imports : Misc.crcs;
cmt_interface_digest : Digest.t option;
cmt_use_summaries : bool;
cmt_uid_to_loc : Location.t Shape.Uid.Tbl.t;
cmt_impl_shape : Shape.t option;
type error =
| Not_a_typedtree of string
exception Error of error
val read : string -> Cmi_format.cmi_infos option * cmt_infos option

read filename opens filename, and extract both the cmi_infos, if it exists, and the cmt_infos, if it exists. Thus, it can be used with .cmi, .cmt and .cmti files.

.cmti files always contain a cmi_infos at the beginning. .cmt files only contain a cmi_infos at the beginning if there is no associated .cmti file.

val read_cmt : string -> cmt_infos
val read_cmi : string -> Cmi_format.cmi_infos
val save_cmt : string -> string -> binary_annots -> string option -> Env.t -> Cmi_format.cmi_infos option -> Shape.t option -> unit

save_cmt filename modname binary_annots sourcefile initial_env cmi writes a cmt(i) file.

val read_magic_number : in_channel -> string
val clear : unit -> unit
val add_saved_type : binary_part -> unit
val get_saved_types : unit -> binary_part list
val set_saved_types : binary_part list -> unit
val record_value_dependency : Types.value_description -> Types.value_description -> unit