+(* Code to generator bindings for virt-inspector. Currently only
+ * implemented for OCaml code (for virt-p2v 2.0).
+ *)
+let rng_input = "inspector/virt-inspector.rng"
+
+(* Read the input file and parse it into internal structures. This is
+ * by no means a complete RELAX NG parser, but is just enough to be
+ * able to parse the specific input file.
+ *)
+type rng =
+ | Element of string * rng list (* <element name=name/> *)
+ | Attribute of string * rng list (* <attribute name=name/> *)
+ | Interleave of rng list (* <interleave/> *)
+ | ZeroOrMore of rng (* <zeroOrMore/> *)
+ | OneOrMore of rng (* <oneOrMore/> *)
+ | Optional of rng (* <optional/> *)
+ | Choice of string list (* <choice><value/>*</choice> *)
+ | Value of string (* <value>str</value> *)
+ | Text (* <text/> *)
+
+let rec string_of_rng = function
+ | Element (name, xs) ->
+ "Element (\"" ^ name ^ "\", (" ^ string_of_rng_list xs ^ "))"
+ | Attribute (name, xs) ->
+ "Attribute (\"" ^ name ^ "\", (" ^ string_of_rng_list xs ^ "))"
+ | Interleave xs -> "Interleave (" ^ string_of_rng_list xs ^ ")"
+ | ZeroOrMore rng -> "ZeroOrMore (" ^ string_of_rng rng ^ ")"
+ | OneOrMore rng -> "OneOrMore (" ^ string_of_rng rng ^ ")"
+ | Optional rng -> "Optional (" ^ string_of_rng rng ^ ")"
+ | Choice values -> "Choice [" ^ String.concat ", " values ^ "]"
+ | Value value -> "Value \"" ^ value ^ "\""
+ | Text -> "Text"
+
+and string_of_rng_list xs =
+ String.concat ", " (List.map string_of_rng xs)
+
+let rec parse_rng ?defines context = function
+ | [] -> []
+ | Xml.Element ("element", ["name", name], children) :: rest ->
+ Element (name, parse_rng ?defines context children)
+ :: parse_rng ?defines context rest
+ | Xml.Element ("attribute", ["name", name], children) :: rest ->
+ Attribute (name, parse_rng ?defines context children)
+ :: parse_rng ?defines context rest
+ | Xml.Element ("interleave", [], children) :: rest ->
+ Interleave (parse_rng ?defines context children)
+ :: parse_rng ?defines context rest
+ | Xml.Element ("zeroOrMore", [], [child]) :: rest ->
+ let rng = parse_rng ?defines context [child] in
+ (match rng with
+ | [child] -> ZeroOrMore child :: parse_rng ?defines context rest
+ | _ ->
+ failwithf "%s: <zeroOrMore> contains more than one child element"
+ context
+ )
+ | Xml.Element ("oneOrMore", [], [child]) :: rest ->
+ let rng = parse_rng ?defines context [child] in
+ (match rng with
+ | [child] -> OneOrMore child :: parse_rng ?defines context rest
+ | _ ->
+ failwithf "%s: <oneOrMore> contains more than one child element"
+ context
+ )
+ | Xml.Element ("optional", [], [child]) :: rest ->
+ let rng = parse_rng ?defines context [child] in
+ (match rng with
+ | [child] -> Optional child :: parse_rng ?defines context rest
+ | _ ->
+ failwithf "%s: <optional> contains more than one child element"
+ context
+ )
+ | Xml.Element ("choice", [], children) :: rest ->
+ let values = List.map (
+ function Xml.Element ("value", [], [Xml.PCData value]) -> value
+ | _ ->
+ failwithf "%s: can't handle anything except <value> in <choice>"
+ context
+ ) children in
+ Choice values
+ :: parse_rng ?defines context rest
+ | Xml.Element ("value", [], [Xml.PCData value]) :: rest ->
+ Value value :: parse_rng ?defines context rest
+ | Xml.Element ("text", [], []) :: rest ->
+ Text :: parse_rng ?defines context rest
+ | Xml.Element ("ref", ["name", name], []) :: rest ->
+ (* Look up the reference. Because of limitations in this parser,
+ * we can't handle arbitrarily nested <ref> yet. You can only
+ * use <ref> from inside <start>.
+ *)
+ (match defines with
+ | None ->
+ failwithf "%s: contains <ref>, but no refs are defined yet" context
+ | Some map ->
+ let rng = StringMap.find name map in
+ rng @ parse_rng ?defines context rest
+ )
+ | x :: _ ->
+ failwithf "%s: can't handle '%s' in schema" context (Xml.to_string x)
+
+let grammar =
+ let xml = Xml.parse_file rng_input in
+ match xml with
+ | Xml.Element ("grammar", _,
+ Xml.Element ("start", _, gram) :: defines) ->
+ (* The <define/> elements are referenced in the <start> section,
+ * so build a map of those first.
+ *)
+ let defines = List.fold_left (
+ fun map ->
+ function Xml.Element ("define", ["name", name], defn) ->
+ StringMap.add name defn map
+ | _ ->
+ failwithf "%s: expected <define name=name/>" rng_input
+ ) StringMap.empty defines in
+ let defines = StringMap.mapi parse_rng defines in
+
+ (* Parse the <start> clause, passing the defines. *)
+ parse_rng ~defines "<start>" gram
+ | _ ->
+ failwithf "%s: input is not <grammar><start/><define>*</grammar>"
+ rng_input
+
+let name_of_field = function
+ | Element (name, _) | Attribute (name, _)
+ | ZeroOrMore (Element (name, _))
+ | OneOrMore (Element (name, _))
+ | Optional (Element (name, _)) -> name
+ | Optional (Attribute (name, _)) -> name
+ | Text -> (* an unnamed field in an element *)
+ "data"
+ | rng ->
+ failwithf "name_of_field failed at: %s" (string_of_rng rng)
+
+(* At the moment this function only generates OCaml types. However we
+ * should parameterize it later so it can generate types/structs in a
+ * variety of languages.
+ *)
+let generate_types xs =
+ (* A simple type is one that can be printed out directly, eg.
+ * "string option". A complex type is one which has a name and has
+ * to be defined via another toplevel definition, eg. a struct.
+ *
+ * generate_type generates code for either simple or complex types.
+ * In the simple case, it returns the string ("string option"). In
+ * the complex case, it returns the name ("mountpoint"). In the
+ * complex case it has to print out the definition before returning,
+ * so it should only be called when we are at the beginning of a
+ * new line (BOL context).
+ *)
+ let rec generate_type = function
+ | Text -> (* string *)
+ "string", true
+ | Choice values -> (* [`val1|`val2|...] *)
+ "[" ^ String.concat "|" (List.map ((^)"`") values) ^ "]", true
+ | ZeroOrMore rng -> (* <rng> list *)
+ let t, is_simple = generate_type rng in
+ t ^ " list (* 0 or more *)", is_simple
+ | OneOrMore rng -> (* <rng> list *)
+ let t, is_simple = generate_type rng in
+ t ^ " list (* 1 or more *)", is_simple
+ (* virt-inspector hack: bool *)
+ | Optional (Attribute (name, [Value "1"])) ->
+ "bool", true
+ | Optional rng -> (* <rng> list *)
+ let t, is_simple = generate_type rng in
+ t ^ " option", is_simple
+ (* type name = { fields ... } *)
+ | Element (name, fields) when is_attrs_interleave fields ->
+ generate_type_struct name (get_attrs_interleave fields)
+ | Element (name, [field]) (* type name = field *)
+ | Attribute (name, [field]) ->
+ let t, is_simple = generate_type field in
+ if is_simple then (t, true)
+ else (
+ pr "type %s = %s\n" name t;
+ name, false
+ )
+ | Element (name, fields) -> (* type name = { fields ... } *)
+ generate_type_struct name fields
+ | rng ->
+ failwithf "generate_type failed at: %s" (string_of_rng rng)
+
+ and is_attrs_interleave = function
+ | [Interleave _] -> true
+ | Attribute _ :: fields -> is_attrs_interleave fields
+ | Optional (Attribute _) :: fields -> is_attrs_interleave fields
+ | _ -> false
+
+ and get_attrs_interleave = function
+ | [Interleave fields] -> fields
+ | ((Attribute _) as field) :: fields
+ | ((Optional (Attribute _)) as field) :: fields ->
+ field :: get_attrs_interleave fields
+ | _ -> assert false
+
+ and generate_types xs =
+ List.iter (fun x -> ignore (generate_type x)) xs
+
+ and generate_type_struct name fields =
+ (* Calculate the types of the fields first. We have to do this
+ * before printing anything so we are still in BOL context.
+ *)
+ let types = List.map fst (List.map generate_type fields) in
+
+ (* Special case of a struct containing just a string and another
+ * field. Turn it into an assoc list.
+ *)
+ match types with
+ | ["string"; other] ->
+ let fname1, fname2 =
+ match fields with
+ | [f1; f2] -> name_of_field f1, name_of_field f2
+ | _ -> assert false in
+ pr "type %s = string * %s (* %s -> %s *)\n" name other fname1 fname2;
+ name, false
+
+ | types ->
+ pr "type %s = {\n" name;
+ List.iter (
+ fun (field, ftype) ->
+ let fname = name_of_field field in
+ pr " %s_%s : %s;\n" name fname ftype
+ ) (List.combine fields types);
+ pr "}\n";
+ (* Return the name of this type, and
+ * false because it's not a simple type.
+ *)
+ name, false
+ in
+
+ generate_types xs
+
+let generate_parsers xs =
+ (* As for generate_type above, generate_parser makes a parser for
+ * some type, and returns the name of the parser it has generated.
+ * Because it (may) need to print something, it should always be
+ * called in BOL context.
+ *)
+ let rec generate_parser = function
+ | Text -> (* string *)
+ "string_child_or_empty"
+ | Choice values -> (* [`val1|`val2|...] *)
+ sprintf "(fun x -> match Xml.pcdata (first_child x) with %s | str -> failwith (\"unexpected field value: \" ^ str))"
+ (String.concat "|"
+ (List.map (fun v -> sprintf "%S -> `%s" v v) values))
+ | ZeroOrMore rng -> (* <rng> list *)
+ let pa = generate_parser rng in
+ sprintf "(fun x -> List.map %s (Xml.children x))" pa
+ | OneOrMore rng -> (* <rng> list *)
+ let pa = generate_parser rng in
+ sprintf "(fun x -> List.map %s (Xml.children x))" pa
+ (* virt-inspector hack: bool *)
+ | Optional (Attribute (name, [Value "1"])) ->
+ sprintf "(fun x -> try ignore (Xml.attrib x %S); true with Xml.No_attribute _ -> false)" name
+ | Optional rng -> (* <rng> list *)
+ let pa = generate_parser rng in
+ sprintf "(function None -> None | Some x -> Some (%s x))" pa
+ (* type name = { fields ... } *)
+ | Element (name, fields) when is_attrs_interleave fields ->
+ generate_parser_struct name (get_attrs_interleave fields)
+ | Element (name, [field]) -> (* type name = field *)
+ let pa = generate_parser field in
+ let parser_name = sprintf "parse_%s_%d" name (unique ()) in
+ pr "let %s =\n" parser_name;
+ pr " %s\n" pa;
+ pr "let parse_%s = %s\n" name parser_name;
+ parser_name
+ | Attribute (name, [field]) ->
+ let pa = generate_parser field in
+ let parser_name = sprintf "parse_%s_%d" name (unique ()) in
+ pr "let %s =\n" parser_name;
+ pr " %s\n" pa;
+ pr "let parse_%s = %s\n" name parser_name;
+ parser_name
+ | Element (name, fields) -> (* type name = { fields ... } *)
+ generate_parser_struct name ([], fields)
+ | rng ->
+ failwithf "generate_parser failed at: %s" (string_of_rng rng)
+
+ and is_attrs_interleave = function
+ | [Interleave _] -> true
+ | Attribute _ :: fields -> is_attrs_interleave fields
+ | Optional (Attribute _) :: fields -> is_attrs_interleave fields
+ | _ -> false
+
+ and get_attrs_interleave = function
+ | [Interleave fields] -> [], fields
+ | ((Attribute _) as field) :: fields
+ | ((Optional (Attribute _)) as field) :: fields ->
+ let attrs, interleaves = get_attrs_interleave fields in
+ (field :: attrs), interleaves
+ | _ -> assert false
+
+ and generate_parsers xs =
+ List.iter (fun x -> ignore (generate_parser x)) xs
+
+ and generate_parser_struct name (attrs, interleaves) =
+ (* Generate parsers for the fields first. We have to do this
+ * before printing anything so we are still in BOL context.
+ *)
+ let fields = attrs @ interleaves in
+ let pas = List.map generate_parser fields in
+
+ (* Generate an intermediate tuple from all the fields first.
+ * If the type is just a string + another field, then we will
+ * return this directly, otherwise it is turned into a record.
+ *
+ * RELAX NG note: This code treats <interleave> and plain lists of
+ * fields the same. In other words, it doesn't bother enforcing
+ * any ordering of fields in the XML.
+ *)
+ pr "let parse_%s x =\n" name;
+ pr " let t = (\n ";
+ let comma = ref false in
+ List.iter (
+ fun x ->
+ if !comma then pr ",\n ";
+ comma := true;
+ match x with
+ | Optional (Attribute (fname, [field])), pa ->
+ pr "%s x" pa
+ | Optional (Element (fname, [field])), pa ->
+ pr "%s (optional_child %S x)" pa fname
+ | Attribute (fname, [Text]), _ ->
+ pr "attribute %S x" fname
+ | (ZeroOrMore _ | OneOrMore _), pa ->
+ pr "%s x" pa
+ | Text, pa ->
+ pr "%s x" pa
+ | (field, pa) ->
+ let fname = name_of_field field in
+ pr "%s (child %S x)" pa fname
+ ) (List.combine fields pas);
+ pr "\n ) in\n";
+
+ (match fields with
+ | [Element (_, [Text]) | Attribute (_, [Text]); _] ->
+ pr " t\n"
+
+ | _ ->
+ pr " (Obj.magic t : %s)\n" name
+(*
+ List.iter (
+ function
+ | (Optional (Attribute (fname, [field])), pa) ->
+ pr " %s_%s =\n" name fname;
+ pr " %s x;\n" pa
+ | (Optional (Element (fname, [field])), pa) ->
+ pr " %s_%s =\n" name fname;
+ pr " (let x = optional_child %S x in\n" fname;
+ pr " %s x);\n" pa
+ | (field, pa) ->
+ let fname = name_of_field field in
+ pr " %s_%s =\n" name fname;
+ pr " (let x = child %S x in\n" fname;
+ pr " %s x);\n" pa
+ ) (List.combine fields pas);
+ pr "}\n"
+*)
+ );
+ sprintf "parse_%s" name
+ in
+
+ generate_parsers xs
+
+(* Generate ocaml/guestfs_inspector.mli. *)
+let generate_ocaml_inspector_mli () =
+ generate_header ~extra_inputs:[rng_input] OCamlStyle LGPLv2plus;
+
+ pr "\
+(** This is an OCaml language binding to the external [virt-inspector]
+ program.
+
+ For more information, please read the man page [virt-inspector(1)].
+*)
+
+";
+
+ generate_types grammar;
+ pr "(** The nested information returned from the {!inspect} function. *)\n";
+ pr "\n";
+
+ pr "\
+val inspect : ?connect:string -> ?xml:string -> string list -> operatingsystems
+(** To inspect a libvirt domain called [name], pass a singleton
+ list: [inspect [name]]. When using libvirt only, you may
+ optionally pass a libvirt URI using [inspect ~connect:uri ...].
+
+ To inspect a disk image or images, pass a list of the filenames
+ of the disk images: [inspect filenames]
+
+ This function inspects the given guest or disk images and
+ returns a list of operating system(s) found and a large amount
+ of information about them. In the vast majority of cases,
+ a virtual machine only contains a single operating system.
+
+ If the optional [~xml] parameter is given, then this function
+ skips running the external virt-inspector program and just
+ parses the given XML directly (which is expected to be XML
+ produced from a previous run of virt-inspector). The list of
+ names and connect URI are ignored in this case.
+
+ This function can throw a wide variety of exceptions, for example
+ if the external virt-inspector program cannot be found, or if
+ it doesn't generate valid XML.
+*)
+"
+
+(* Generate ocaml/guestfs_inspector.ml. *)
+let generate_ocaml_inspector_ml () =
+ generate_header ~extra_inputs:[rng_input] OCamlStyle LGPLv2plus;
+
+ pr "open Unix\n";
+ pr "\n";
+
+ generate_types grammar;
+ pr "\n";
+
+ pr "\
+(* Misc functions which are used by the parser code below. *)
+let first_child = function
+ | Xml.Element (_, _, c::_) -> c
+ | Xml.Element (name, _, []) ->
+ failwith (\"expected <\" ^ name ^ \"/> to have a child node\")
+ | Xml.PCData str ->
+ failwith (\"expected XML tag, but read PCDATA '\" ^ str ^ \"' instead\")
+
+let string_child_or_empty = function
+ | Xml.Element (_, _, [Xml.PCData s]) -> s
+ | Xml.Element (_, _, []) -> \"\"
+ | Xml.Element (x, _, _) ->
+ failwith (\"expected XML tag with a single PCDATA child, but got \" ^
+ x ^ \" instead\")
+ | Xml.PCData str ->
+ failwith (\"expected XML tag, but read PCDATA '\" ^ str ^ \"' instead\")
+
+let optional_child name xml =
+ let children = Xml.children xml in
+ try
+ Some (List.find (function
+ | Xml.Element (n, _, _) when n = name -> true
+ | _ -> false) children)
+ with
+ Not_found -> None
+
+let child name xml =
+ match optional_child name xml with
+ | Some c -> c
+ | None ->
+ failwith (\"mandatory field <\" ^ name ^ \"/> missing in XML output\")
+
+let attribute name xml =
+ try Xml.attrib xml name
+ with Xml.No_attribute _ ->
+ failwith (\"mandatory attribute \" ^ name ^ \" missing in XML output\")
+
+";
+
+ generate_parsers grammar;
+ pr "\n";
+
+ pr "\
+(* Run external virt-inspector, then use parser to parse the XML. *)
+let inspect ?connect ?xml names =
+ let xml =
+ match xml with
+ | None ->
+ if names = [] then invalid_arg \"inspect: no names given\";
+ let cmd = [ \"virt-inspector\"; \"--xml\" ] @
+ (match connect with None -> [] | Some uri -> [ \"--connect\"; uri ]) @
+ names in
+ let cmd = List.map Filename.quote cmd in
+ let cmd = String.concat \" \" cmd in
+ let chan = open_process_in cmd in
+ let xml = Xml.parse_in chan in
+ (match close_process_in chan with
+ | WEXITED 0 -> ()
+ | WEXITED _ -> failwith \"external virt-inspector command failed\"
+ | WSIGNALED i | WSTOPPED i ->
+ failwith (\"external virt-inspector command died or stopped on sig \" ^
+ string_of_int i)
+ );
+ xml
+ | Some doc ->
+ Xml.parse_string doc in
+ parse_operatingsystems xml
+"
+
git.annexia.org / libguestfs.git / blobdiff