# HG changeset patch
# User Rok Strnisa <rok.strnisa@xxxxxxxxxx>
# Date 1289323370 0
# Node ID 403764544b97988f2e3d5c1cd4608c34f61863b6
# Parent  dd7e1f8d25ff8d75000725cc053d007cb2c838e2
imported patch removing-warnings

diff --git a/ocaml/idl/dm_api.ml b/ocaml/idl/dm_api.ml
--- a/ocaml/idl/dm_api.ml
+++ b/ocaml/idl/dm_api.ml
@@ -193,8 +193,8 @@ let check api emergency_calls =
 
   (* Sanity check 7: message parameters must be in increasing order of in_product_since *)
   let are_in_vsn_order ps =
-    let rec getlast l =
-      match l with [x] -> x | x::xs -> getlast xs in
+    let rec getlast l = (* TODO: move to standard library *)
+      match l with [x] -> x | _::xs -> getlast xs | [] -> raise (Invalid_argument "getlast") in
     let release_lt x y = release_leq x y && x<>y in
     let in_since releases = (* been in since the lowest of releases *)
       let rec find_smallest sofar l =
diff --git a/ocaml/idl/ocaml_backend/event_helper.ml b/ocaml/idl/ocaml_backend/event_helper.ml
--- a/ocaml/idl/ocaml_backend/event_helper.ml
+++ b/ocaml/idl/ocaml_backend/event_helper.ml
@@ -72,4 +72,4 @@ open Pervasiveext
      | "message" ->          Message (Ref.of_string ev.Event_types.reference,API.From.message_t "" xmlrpc)
      | "secret" ->           Secret (Ref.of_string ev.Event_types.reference,API.From.secret_t "" xmlrpc)
      | "vmpp" ->             VMPP (Ref.of_string ev.Event_types.reference,API.From.vMPP_t "" xmlrpc)
-  
+     | _ -> failwith "unknown event type"
diff --git a/ocaml/idl/ocaml_backend/gen_db_actions.ml b/ocaml/idl/ocaml_backend/gen_db_actions.ml
--- a/ocaml/idl/ocaml_backend/gen_db_actions.ml
+++ b/ocaml/idl/ocaml_backend/gen_db_actions.ml
@@ -232,7 +232,7 @@ let db_action api : O.Module.t =
 
     let get_record_aux_fn_body ?(m="API.") (obj: obj) (all_fields: field list) =
       let fields = List.filter field_in_this_table all_fields in
-      let sql_fields = List.map (fun f -> Escaping.escape_id f.full_name) fields in
+      let _ (* sql_fields *) = List.map (fun f -> Escaping.escape_id f.full_name) fields in
 	
       let of_field = function
 	| { DT.ty = DT.Set(DT.Ref other); full_name = full_name; DT.field_ignore_foreign_key = false } ->
@@ -267,8 +267,8 @@ let db_action api : O.Module.t =
 	  ~body: [ get_record_aux_fn_body ~m:"" obj record_fields ] () in
       
     let get_records_where (obj: obj) name conversion_fn = 
-      let record_name = OU.ocaml_of_record_name obj.DT.name in
-      let ref_name = OU.alias_of_ty (Ref obj.DT.name) in
+      let _ (* record_name *) = OU.ocaml_of_record_name obj.DT.name in
+      let _ (* ref_name *) = OU.alias_of_ty (Ref obj.DT.name) in
 	O.Let.make
 	  ~name: name
 	  ~params: [ Gen_common.context_arg; expr_arg ]
@@ -297,7 +297,7 @@ let db_action api : O.Module.t =
       let converter = O.type_of_param arg in
       Printf.sprintf "let %s = %s.%s %s in" binding _dm_to_string converter binding in
 
-    let snapshot self = snapshot obj.DT.name self in
+    (* let snapshot self = snapshot obj.DT.name self in *)
 
     let body = match tag with
       | FromField(Setter, fld) ->
diff --git a/ocaml/idl/ocaml_backend/gen_rbac.ml b/ocaml/idl/ocaml_backend/gen_rbac.ml
--- a/ocaml/idl/ocaml_backend/gen_rbac.ml
+++ b/ocaml/idl/ocaml_backend/gen_rbac.ml
@@ -313,10 +313,10 @@ let gen_permissions_of_static_roles high
 	let api_roles_permissions = 
 		(get_roles_permissions_of_objs ([],all_objs)) (*api*)
 	in
-	let http_roles_permissions = 
+	let _ (* http_roles_permissions *) =
 		(gen_roles_of_permissions get_http_permissions_roles) (*http*)
 	in
-	let extra_roles_permisions = (* extra, not associated to api or http calls *)
+	let _ (* extra_roles_permisions *) = (* extra, not associated to api or http calls *)
 		(gen_roles_of_permissions get_extra_permissions_roles)
 	in
 	let roles_permissions = (*api+http+extra*)
diff --git a/ocaml/idl/ocaml_backend/gen_server.ml b/ocaml/idl/ocaml_backend/gen_server.ml
--- a/ocaml/idl/ocaml_backend/gen_server.ml
+++ b/ocaml/idl/ocaml_backend/gen_server.ml
@@ -79,12 +79,12 @@ let operation (obj: obj) (x: message) =
   let msg_without_default_values = {x with DT.msg_params=msg_params_without_default_values} in
   
   let all_args = Client.args_of_message obj x in
-  let args_with_default_values = Client.args_of_message obj msg_with_default_values in
+  let _ (* args_with_default_values *) = Client.args_of_message obj msg_with_default_values in
   let args_without_default_values = Client.args_of_message obj msg_without_default_values in
   
   (* Constructors use a <struct> on the wire *)
   let is_ctor = x.msg_tag = FromObject(Make) && Client.use_structure_in_ctor in    
-  let task = DT.Ref Datamodel._task in
+  let _ (* task *) = DT.Ref Datamodel._task in
     
   (* Result marshaller converts the result to a string for the Task table *)
   let result_marshaller = match x.msg_custom_marshaller, x.msg_result with
@@ -209,7 +209,7 @@ let operation (obj: obj) (x: message) =
 		let ret = match x.msg_result with Some(ty, _) -> Some ty | _ -> None in
 		let type_xml = XMLRPC.TypeToXML.marshal ret in
 		let module_prefix = if (Gen_empty_custom.operation_requires_side_effect x) then _custom else _db_defaults in
-		let cls = OU.ocaml_of_obj_name obj.DT.name in
+		let _ (* cls *) = OU.ocaml_of_obj_name obj.DT.name in
 		let common_let_decs =
 			[
 				"let marshaller = "^result_marshaller^" in";
diff --git a/ocaml/perftest/createVM.ml b/ocaml/perftest/createVM.ml
--- a/ocaml/perftest/createVM.ml
+++ b/ocaml/perftest/createVM.ml
@@ -38,7 +38,7 @@ let make_iscsi session_id pool network =
     let template = List.hd (Client.VM.get_by_name_label rpc session_id iscsi_vm_template) in
     let newvm = Client.VM.clone rpc session_id template "ISCSI target server" in
     Client.VM.provision rpc session_id newvm;
-    let isovbd = Client.VBD.create rpc session_id newvm iscsi_iso "0" true `RO `CD false false [] "" [] in
+    let _ (* isovbd *) = Client.VBD.create rpc session_id newvm iscsi_iso "0" true `RO `CD false false [] "" [] in
     let realpool = List.hd (Client.Pool.get_all rpc session_id) in
     let defaultsr = Client.Pool.get_default_SR rpc session_id realpool in
 
@@ -46,7 +46,7 @@ let make_iscsi session_id pool network =
       let storage_vdi_label = Printf.sprintf "SCSI VDI %d" i in
       let storage_vdi = Client.VDI.create rpc session_id storage_vdi_label "" defaultsr sr_disk_size `user false false [oc_key,pool.key] [] [] [] in
       let userdevice = Printf.sprintf "%d" (i+1) in
-      Client.VBD.create rpc session_id newvm storage_vdi userdevice false `RW `Disk false false [] "" []
+      ignore(Client.VBD.create rpc session_id newvm storage_vdi userdevice false `RW `Disk false false [] "" [])
     done;
 
     Client.VM.set_PV_bootloader rpc session_id newvm "pygrub";
diff --git a/ocaml/util/stats.ml b/ocaml/util/stats.ml
--- a/ocaml/util/stats.ml
+++ b/ocaml/util/stats.ml
@@ -72,9 +72,9 @@ let string_of (p: Normal_population.t) =
 let sample (name: string) (x: float) = 
   (* Use the lognormal distribution: *)
   let x' = log x in
-  let p = Mutex.execute timings_m
+  let _ (* p *) = Mutex.execute timings_m
     (fun () ->
-       let p = 
+       let p =
 	 if Hashtbl.mem timings name 
 	 then Hashtbl.find timings name 
 	 else Normal_population.empty in
diff --git a/ocaml/xapi/dbsync_slave.ml b/ocaml/xapi/dbsync_slave.ml
--- a/ocaml/xapi/dbsync_slave.ml
+++ b/ocaml/xapi/dbsync_slave.ml
@@ -154,8 +154,8 @@ let update_vms ~xal ~__context =
     List.filter (fun (_, vm_r) -> not (Db.is_valid_ref vm_r.API.vM_resident_on)) all_scheduled_to_be_resident_on_vms in
   let all_vms_assigned_to_me = Listext.List.setify (all_resident_on_vms @ really_my_scheduled_to_be_resident_on_vms) in
 
-  let all_vbds = Db.VBD.get_records_where ~__context ~expr:Db_filter_types.True in
-  let all_vifs = Db.VIF.get_records_where ~__context ~expr:Db_filter_types.True in
+  let _ (* all_vbds *) = Db.VBD.get_records_where ~__context ~expr:Db_filter_types.True in
+  let _ (* all_vifs *) = Db.VIF.get_records_where ~__context ~expr:Db_filter_types.True in
 
   let power_states_where_domain_exists = [ `Running; `Paused ] in
   let my_running_vms_according_to_db =
@@ -296,8 +296,8 @@ let update_vms ~xal ~__context =
     debug "killing umanaged domain: %s" (uuid_from_dinfo dinfo);
     Domain.destroy ~xc ~xs dinfo.Xc.domid (* bye-bye... *) in
 
-  let all_vm_refs = List.map fst all_vms_assigned_to_me in
-  let have_record_for dinfo = try let vmref,_ = vmrefrec_of_dinfo dinfo in true with _ -> false in
+  let _ (* all_vm_refs *) = List.map fst all_vms_assigned_to_me in
+  let have_record_for dinfo = try let _ (* vmref *), _ = vmrefrec_of_dinfo dinfo in true with _ -> false in
 
   let all_my_managed_domains = List.filter have_record_for all_my_domains in
   let my_active_managed_domains = List.filter have_record_for my_active_domains in
diff --git a/ocaml/xapi/events.ml b/ocaml/xapi/events.ml
--- a/ocaml/xapi/events.ml
+++ b/ocaml/xapi/events.ml
@@ -279,7 +279,7 @@ module Resync = struct
 
     with_xs
       (fun xs ->
-	 let protocol = Helpers.device_protocol_of_string (Db.VM.get_domarch ~__context ~self:vm) in
+	 let _ (* protocol *) = Helpers.device_protocol_of_string (Db.VM.get_domarch ~__context ~self:vm) in
 	 (* This is what the DB thinks: *)
 	 let is_attached = Db.VIF.get_currently_attached ~__context ~self:vif in
 	 let device = Xen_helpers.device_of_vif ~__context ~self:vif in
@@ -497,7 +497,7 @@ let callback_devices ctx domid dev_event
 		       then Hashtbl.replace Monitor.uncooperative_domains domid ()
 		       else Hashtbl.remove Monitor.uncooperative_domains domid
 		    )
-	      | x -> debug "no handler for this event"
+	      (*unused case, consider removing: | x -> debug "no handler for this event"*)
 		  
 	    with Vm_corresponding_to_domid_not_in_db domid ->
 	      error "device_event could not be processed because VM record not in database"
diff --git a/ocaml/xapi/message_forwarding.ml b/ocaml/xapi/message_forwarding.ml
--- a/ocaml/xapi/message_forwarding.ml
+++ b/ocaml/xapi/message_forwarding.ml
@@ -17,6 +17,7 @@
  
 open Threadext
 open Pervasiveext
+open Listext
 open Stringext
 open Server_helpers
 open Client
@@ -72,14 +73,14 @@ module Early_wakeup = struct
     finally
       (fun () -> 
 	 let start = Unix.gettimeofday () in
-	 let waited_full_length = Delay.wait d time in
-	 let time_sleeping = Unix.gettimeofday () -. start in
+	 let _ (* waited_full_length *) = Delay.wait d time in
+	 let _ (* time_sleeping *) = Unix.gettimeofday () -. start in
 	 (* debug "Early_wakeup %s key = (%s, %s) after %.2f (speedup %.2f seconds)" 
 	   (if waited_full_length then "slept" else "woken") a b time_sleeping (time -. time_sleeping)
      *)() )
       (fun () -> Mutex.execute table_m (fun () -> Hashtbl.remove table key))
       
-  let broadcast ((a, b) as key) = 
+  let broadcast (a, b) (* ((a, b) as key) *) =
     (*debug "Early_wakeup broadcast key = (%s, %s)" a b;*)
     Mutex.execute table_m 
       (fun () -> 
@@ -900,7 +901,7 @@ module Forward = functor(Local: Custom_a
 
     let clone ~__context ~vm ~new_name =
       info "VM.clone: VM = '%s'; new_name = '%s'" (vm_uuid ~__context vm) new_name;
-      let task_id = Ref.string_of (Context.get_task_id __context) in
+      let _ (* task_id *) = Ref.string_of (Context.get_task_id __context) in
       let local_fn = Local.VM.clone ~vm ~new_name in
       (* We mark the VM as cloning. We don't mark the disks; the implementation of the clone
 	 uses the API to clone and lock the individual VDIs. We don't give any atomicity
@@ -919,7 +920,7 @@ module Forward = functor(Local: Custom_a
 (* almost a copy of the clone function *)
     let snapshot ~__context ~vm ~new_name =
       info "VM.snapshot: VM = '%s'; new_name = '%s'" (vm_uuid ~__context vm) new_name;
-      let task_id = Ref.string_of (Context.get_task_id __context) in
+      let _ (* task_id *) = Ref.string_of (Context.get_task_id __context) in
       let local_fn = Local.VM.snapshot ~vm ~new_name in
         (* We mark the VM as snapshoting. We don't mark the disks; the implementation of the snapshot uses the API   *)
         (* to snapshot and lock the individual VDIs. We don't give any atomicity guarantees here but we do prevent   *)
@@ -931,7 +932,7 @@ module Forward = functor(Local: Custom_a
 
     let snapshot_with_quiesce ~__context ~vm ~new_name =
       info "VM.snapshot_with_quiesce: VM = '%s'; new_name = '%s'" (vm_uuid ~__context vm) new_name;
-      let task_id = Ref.string_of (Context.get_task_id __context) in
+      let _ (* task_id *) = Ref.string_of (Context.get_task_id __context) in
       let local_fn = Local.VM.snapshot_with_quiesce ~vm ~new_name in
         (* We mark the VM as snapshoting. We don't mark the disks; the implementation of the snapshot uses the API   *)
         (* to snapshot and lock the individual VDIs. We don't give any atomicity guarantees here but we do prevent   *)
@@ -959,7 +960,7 @@ module Forward = functor(Local: Custom_a
 
     let copy ~__context ~vm ~new_name ~sr =
       info "VM.copy: VM = '%s'; new_name = '%s'; SR = '%s'" (vm_uuid ~__context vm) new_name (sr_uuid ~__context sr);
-      let task_id = Ref.string_of (Context.get_task_id __context) in
+      let _ (* task_id *) = Ref.string_of (Context.get_task_id __context) in
       let local_fn = Local.VM.copy ~vm ~new_name ~sr in
       (* We mark the VM as cloning. We don't mark the disks; the implementation of the clone
 	 uses the API to clone and lock the individual VDIs. We don't give any atomicity
@@ -1080,7 +1081,7 @@ module Forward = functor(Local: Custom_a
 			    (fun session_id rpc -> Client.VM.start rpc session_id vm start_paused force)))));
       update_vbd_operations ~__context ~vm;      
       update_vif_operations ~__context ~vm;
-      let uuid = Db.VM.get_uuid ~__context ~self:vm in
+      let _ (* uuid *) = Db.VM.get_uuid ~__context ~self:vm in
       let message_body = 
 	Printf.sprintf "VM '%s' started on host: %s (uuid: %s)" 
 	  (Db.VM.get_name_label ~__context ~self:vm)
@@ -1177,8 +1178,7 @@ module Forward = functor(Local: Custom_a
 			else
 			  Some (Db.VBD.get_VDI ~__context ~self:vbd))
 		     (Db.VM.get_VBDs ~__context ~self:vm) in
-		 let all_vm_vdis = List.filter (fun x -> match x with (Some _) -> true | _ -> false) all_vm_vdis in
-		 let all_vm_vdis = List.map (fun x -> match x with (Some y)->y) all_vm_vdis in
+		 let all_vm_vdis = List.unbox_list all_vm_vdis in
 		 let all_vm_srs = List.map (fun vdi -> Db.VDI.get_SR ~self:vdi ~__context) all_vm_vdis in
 		 let suitable_host = Xapi_vm_helpers.choose_host ~__context ~vm:vm
 		   ~choose_fn:(Xapi_vm_helpers.assert_can_see_specified_SRs ~__context ~reqd_srs:all_vm_srs) () in
@@ -1293,7 +1293,7 @@ module Forward = functor(Local: Custom_a
     (* same forwarding logic as clone *)
     let csvm ~__context ~vm =
       info "VM.csvm: VM = '%s'" (vm_uuid ~__context vm);
-      let task_id = Ref.string_of (Context.get_task_id __context) in
+      let _ (* task_id *) = Ref.string_of (Context.get_task_id __context) in
       let local_fn = Local.VM.csvm ~vm in
       (* We mark the VM as cloning. We don't mark the disks; the implementation of the clone
 	 uses the API to clone and lock the individual VDIs. We don't give any atomicity
@@ -2924,7 +2924,7 @@ end
     let generate_config ~__context ~host ~vdi =
       info "VDI.generate_config: VDI = '%s'; host = '%s'" (vdi_uuid ~__context vdi) (host_uuid ~__context host);
       let local_fn = Local.VDI.generate_config ~host ~vdi in
-      let sR = Db.VDI.get_SR ~__context ~self:vdi in
+      let _ (* sR *) = Db.VDI.get_SR ~__context ~self:vdi in
       with_sr_andor_vdi ~__context ~vdi:(vdi, `generate_config) ~doc:"VDI.generate_config"
 	(fun () ->
 	   do_op_on ~local_fn ~__context ~host 
diff --git a/ocaml/xapi/sparse_dd.ml b/ocaml/xapi/sparse_dd.ml
--- a/ocaml/xapi/sparse_dd.ml
+++ b/ocaml/xapi/sparse_dd.ml
@@ -20,7 +20,7 @@ exception ShortWrite of int (* offset *)
 (* Consider a tunable quantum of non-zero'ness such that if we encounter
    a non-zero, we know we're going to incur the penalty of a seek/write
    and we may as well write a sizeable chunk at a time. *)
-let roundup x = 
+let roundup x =
 	let quantum = 16384 in
 	((x + quantum + quantum - 1) / quantum) * quantum
 
@@ -113,13 +113,13 @@ end
 module File_reader = struct
 	type t = Unix.file_descr
 	let op stream stream_offset { buf = buf; offset = offset; len = len } = 
-		Unix.LargeFile.lseek stream stream_offset Unix.SEEK_SET; 
-		Unixext.really_read stream buf offset len 
+		ignore(Unix.LargeFile.lseek stream stream_offset Unix.SEEK_SET);
+		Unixext.really_read stream buf offset len
 end
 module File_writer = struct
 	type t = Unix.file_descr
 	let op stream stream_offset { buf = buf; offset = offset; len = len } = 
-		let newoff = Unix.LargeFile.lseek stream stream_offset Unix.SEEK_SET in
+		let _ (* newoff *) = Unix.LargeFile.lseek stream stream_offset Unix.SEEK_SET in
 		(* Printf.printf "Unix.write buf len %d; offset %d; len %d\n" (String.length buf) offset len; *)
 		let n = Unix.write stream buf offset len in
 		if n < len
@@ -246,9 +246,9 @@ let file_dd ?(progress_cb = (fun _ -> ()
 	end else begin
 		let ofd = Unix.openfile dst [ Unix.O_WRONLY; Unix.O_CREAT ] 0o600 in
 	 	(* Make sure the output file has the right size *)
-		Unix.LargeFile.lseek ofd (size -* 1L) Unix.SEEK_SET;
-		Unix.write ofd "\000" 0 1;
-		Unix.LargeFile.lseek ofd 0L Unix.SEEK_SET;
+		ignore(Unix.LargeFile.lseek ofd (size -* 1L) Unix.SEEK_SET);
+		ignore(Unix.write ofd "\000" 0 1);
+		ignore(Unix.LargeFile.lseek ofd 0L Unix.SEEK_SET);
 		Printf.printf "Copying\n";
 		File_copy.copy progress_cb bat prezeroed ifd ofd blocksize size
 	end 
diff --git a/ocaml/xapi/xapi.ml b/ocaml/xapi/xapi.ml
--- a/ocaml/xapi/xapi.ml
+++ b/ocaml/xapi/xapi.ml
@@ -719,7 +719,7 @@ let server_init() =
       let service_name = Db.Host.get_external_auth_service_name ~__context ~self:host in
       let last_error = ref None in
       (* watchdog to indicate that on_xapi_initialize wasn't successful after 2 min initializing *)
-      Thread.create (fun ()-> Thread.delay (2.0 *. 60.0); (* wait 2min before testing for success *)
+      ignore(Thread.create (fun ()-> Thread.delay (2.0 *. 60.0); (* wait 2min before testing for success *)
         if not !Xapi_globs.event_hook_auth_on_xapi_initialize_succeeded then
         begin (* no success after 2 min *)
           let obj_uuid = Helpers.get_localhost_uuid () in
@@ -738,7 +738,7 @@ let server_init() =
             );
           ));
         end
-      ) ();
+      ) ());
       (* persistent loop trying to initialize the external authentication service *)
       (* obs: this loop will also end after a host.disable_external_auth call *)
       while (not !Xapi_globs.event_hook_auth_on_xapi_initialize_succeeded) do
diff --git a/ocaml/xapi/xapi_host.ml b/ocaml/xapi/xapi_host.ml
--- a/ocaml/xapi/xapi_host.ml
+++ b/ocaml/xapi/xapi_host.ml
@@ -111,11 +111,11 @@ let assert_bacon_mode ~__context ~host =
 	let vms = Db.VM.get_refs_where ~__context ~expr:(And(Eq (Field "resident_on", Literal (Ref.string_of host)),
 									Eq (Field "power_state", Literal "Running"))) in
 	(* We always expect a control domain to be resident on a host *)
-	match List.filter (fun vm -> not (Db.VM.get_is_control_domain ~__context ~self:vm)) vms with
+	(match List.filter (fun vm -> not (Db.VM.get_is_control_domain ~__context ~self:vm)) vms with
 	| [] -> ()
 	| guest_vms -> 
 		let vm_data = [selfref; "vm"; Ref.string_of (List.hd guest_vms)] in
-		raise (Api_errors.Server_error (Api_errors.host_in_use, vm_data))
+		raise (Api_errors.Server_error (Api_errors.host_in_use, vm_data)));
 	debug "Bacon test: VMs OK - %d running VMs" (List.length vms);
 	let controldomain = List.find (fun vm -> Db.VM.get_resident_on ~__context ~self:vm = host &&
 			Db.VM.get_is_control_domain ~__context ~self:vm) (Db.VM.get_all ~__context) in  
@@ -619,12 +619,12 @@ let license_apply ~__context ~host ~cont
 
 let create ~__context ~uuid ~name_label ~name_description ~hostname ~address ~external_auth_type ~external_auth_service_name ~external_auth_configuration ~license_params ~edition ~license_server =
 
-  let existing_host = try Some (Db.Host.get_by_uuid __context uuid) with _ -> None in
+  let _ (* existing_host *) = try Some (Db.Host.get_by_uuid __context uuid) with _ -> None in
   let make_new_metrics_object ref =
     Db.Host_metrics.create ~__context ~ref
       ~uuid:(Uuid.to_string (Uuid.make_uuid ())) ~live:false
       ~memory_total:0L ~memory_free:0L ~last_updated:Date.never ~other_config:[] in
-  let xapi_verstring = get_xapi_verstring() in
+  let _ (* xapi_verstring *) = get_xapi_verstring() in
   let name_description = "Default install of XenServer"
   and host = Ref.make () in
   
@@ -1161,7 +1161,7 @@ let disable_external_auth_common ?during
 			(Ext_auth.d()).on_disable config;
 			None (* OK, on_disable succeeded *)
 		with 
-		| Auth_signature.Auth_service_error (errtag,msg) as e ->
+		| Auth_signature.Auth_service_error (errtag,msg) (* as e *) ->
 			begin
 				debug "Failed while calling on_disable event of external authentication plugin in host %s: %s" host_name_label msg;
 				Some (Api_errors.Server_error(Api_errors.auth_disable_failed^(Auth_signature.suffix_of_tag errtag), [msg]))
diff --git a/ocaml/xapi/xapi_pool.ml b/ocaml/xapi/xapi_pool.ml
--- a/ocaml/xapi/xapi_pool.ml
+++ b/ocaml/xapi/xapi_pool.ml
@@ -295,7 +295,7 @@ let rec create_or_get_host_on_master __c
 			(* Copy the suspend image SR *)
 			let my_suspend_image_sr = Db.Host.get_crash_dump_sr ~__context ~self:host_ref in
 			let my_suspend_image_sr_rec = Db.SR.get_record ~__context ~self:my_suspend_image_sr in
-			let syspend_image_sr = create_or_get_sr_on_master __context rpc session_id (my_suspend_image_sr, my_suspend_image_sr_rec) in
+			let _ (* syspend_image_sr *) = create_or_get_sr_on_master __context rpc session_id (my_suspend_image_sr, my_suspend_image_sr_rec) in
 			no_exn (fun () -> Client.Host.set_crash_dump_sr ~rpc ~session_id ~self:ref ~value:my_suspend_image_sr) ();
 
 			ref in
@@ -820,7 +820,7 @@ let is_slave ~__context ~host =
   let is_slave = not (Pool_role.is_master ()) in
   info "Pool.is_slave call received (I'm a %s)" (if is_slave then "slave" else "master");
   debug "About to kick the database connection to make sure it's still working...";
-  Db.is_valid_ref (Ref.of_string "Pool.is_slave checking to see if the database connection is up");
+  ignore(Db.is_valid_ref (Ref.of_string "Pool.is_slave checking to see if the database connection is up"));
   is_slave
 
 let hello ~__context ~host_uuid ~host_address =
@@ -867,7 +867,7 @@ let hello ~__context ~host_uuid ~host_ad
 
 	(* Update the heartbeat timestamp for this host so we don't mark it as 
 	   offline in the next db_gc *)
-	Db_gc.tickle_heartbeat ~__context host_ref [];
+	ignore(Db_gc.tickle_heartbeat ~__context host_ref []);
 	`ok
       with e ->
 	debug "Caught exception: %s" (ExnHelper.string_of_exn e);
@@ -1278,7 +1278,7 @@ let disable_external_auth ~__context ~po
 				(* no failed host to add to the filtered list, just visit next host *)
 				(host,"","")
 			with 
-			| Api_errors.Server_error (err,[host_msg]) as e -> begin
+			| Api_errors.Server_error (err,[host_msg]) (* as e *) -> begin
 				let msg = (Printf.sprintf "%s: %s" 
 					(Db.Host.get_name_label ~__context ~self:host) host_msg) in
 				debug "Failed to disable the external authentication of pool in host %s" msg;
@@ -1449,7 +1449,7 @@ let disable_redo_log ~__context =
 
 let assert_is_valid_ip ip_addr =
  	if ip_addr <> "" then
-	try Unix.inet_addr_of_string ip_addr; ()
+	try ignore(Unix.inet_addr_of_string ip_addr)
 	with _ -> raise (Api_errors.Server_error (Api_errors.invalid_ip_address_specified, [ "address" ]))
 
 let set_vswitch_controller ~__context ~address =
@@ -1472,8 +1472,7 @@ let audit_log_append ~__context ~line =
 	(* this is necessary here because the slave doesn't have access to these names *)
 	let line = Rbac_audit.populate_audit_record_with_obj_names_of_refs line in
 	(* copy audit record from slave exactly as it is, without any new prefixes *)
-	Rbac_audit.append_line ~raw:true "%s" line;
-	()
+	ignore(Rbac_audit.append_line ~raw:true "%s" line)
 
 let test_archive_target ~__context ~self ~config =
   Xapi_plugins.call_plugin
diff --git a/ocaml/xapi/xapi_vm.ml b/ocaml/xapi/xapi_vm.ml
--- a/ocaml/xapi/xapi_vm.ml
+++ b/ocaml/xapi/xapi_vm.ml
@@ -159,8 +159,6 @@ let set_memory_limits ~__context ~self
 	if Db.VM.get_power_state ~__context ~self <> `Halted
 	then failwith "assertion_failed: set_memory_limits should only be \
 		called when the VM is Halted";
-	(* Support the redundant target field. *)
-	let target = dynamic_min in
 	(* Check that the new limits are in the correct order. *)
 	let constraints = {Vm_memory_constraints.
 		static_min  = static_min;
@@ -629,7 +627,7 @@ let hard_shutdown ~__context ~vm =
 		let args = { TwoPhase.__context=__context; vm=vm; api_call_name="VM.hard_shutdown"; clean=false } in
 		retry_on_conflict args (of_action action)
 	with
-		| Api_errors.Server_error(code, _) as e
+		| Api_errors.Server_error(code, _) (* as e *)
 				when code = Api_errors.vm_bad_power_state ->
 			(* ToDo: How do you test directly if the VM is already shut-down?
 			   I hope we are not masking bugs here.
diff --git a/ocaml/xenops/domain.ml b/ocaml/xenops/domain.ml
--- a/ocaml/xenops/domain.ml
+++ b/ocaml/xenops/domain.ml
@@ -392,7 +392,7 @@ let build_pre ~xc ~xs ~vcpus ~xen_max_mi
 		domid xen_max_mib shadow_mib required_host_free_mib;
 
 	(* CA-39743: Wait, if necessary, for the Xen scrubber to catch up. *)
-	Memory.wait_xen_free_mem ~xc (Memory.kib_of_mib required_host_free_mib);
+	ignore(Memory.wait_xen_free_mem ~xc (Memory.kib_of_mib required_host_free_mib));
 
 	let shadow_mib = Int64.to_int shadow_mib in
 
diff --git a/ocaml/xenops/squeeze.ml b/ocaml/xenops/squeeze.ml
--- a/ocaml/xenops/squeeze.ml
+++ b/ocaml/xenops/squeeze.ml
@@ -373,7 +373,7 @@ module Squeezer = struct
 		let max_target domain = domain.target_kib = domain.dynamic_max_kib in
 
 		let cant_allocate_any_more = all max_target active_domains in
-		let cant_free_any_more = all min_target active_domains in
+		let _ (* cant_free_any_more *) = all min_target active_domains in
 
 		(* Note the asymmetry between:
 		   1. increasing free memory: if we think we can't free enough then we give up
@@ -604,7 +604,7 @@ let is_host_memory_unbalanced ?fistpoint
   let debug_string, host = io.make_host () in
   let domains = List.map (fun d -> d.domid, d) host.domains in
 
-  let t = io.gettimeofday () in
+  let _ (* t *) = io.gettimeofday () in
   let _, _, _, result = Squeezer.one_iteration ?fistpoints false
     (is_balanced io) (Squeezer.make ()) host 
     io.target_host_free_mem_kib (io.gettimeofday ()) in
diff --git a/ocaml/xenops/squeeze_xen.ml b/ocaml/xenops/squeeze_xen.ml
--- a/ocaml/xenops/squeeze_xen.ml
+++ b/ocaml/xenops/squeeze_xen.ml
@@ -227,7 +227,7 @@ let update_cooperative_flags cnx =
 let make_host ~verbose ~xc ~xs =
 	(* Wait for any scrubbing so that we don't end up with no immediately usable pages --
 	   this might cause something else to fail (eg domain builder?) *)
-	while Memory.get_scrub_memory_kib ~xc <> 0L do Unix.select [] [] [] 0.25 done;
+	while Memory.get_scrub_memory_kib ~xc <> 0L do ignore(Unix.select [] [] [] 0.25) done;
 
 	(* Some VMs are considered by us (but not by xen) to have an "initial-reservation". For VMs which have never 
 	   run (eg which are still being built or restored) we take the difference between memory_actual_kib and the
diff --git a/ocaml/xenops/watch.ml b/ocaml/xenops/watch.ml
--- a/ocaml/xenops/watch.ml
+++ b/ocaml/xenops/watch.ml
@@ -42,7 +42,7 @@ let wait_for ~xs ?(timeout=60. *. 20.) (
   let result = ref None in
 
   let start_time = Unix.gettimeofday () in
-  let time_taken () = Unix.gettimeofday () -. start_time in
+  (* let time_taken () = Unix.gettimeofday () -. start_time in *)
 
   let callback (path, _) = 
     match x.evaluate ~xs with
diff --git a/ocaml/xenops/xal.ml b/ocaml/xenops/xal.ml
--- a/ocaml/xenops/xal.ml
+++ b/ocaml/xenops/xal.ml
@@ -65,7 +65,6 @@ let string_of_dev_state = function
 
 let string_of_dev_event ev =
 	let string_of_string_opt = function None -> "\"\"" | Some s -> s in
-	let string_of_b b = if b then "B" else "F" in
 	match ev with
 	| DevEject i ->
 		sprintf "device eject {%s}" i
@@ -573,10 +572,10 @@ let domain_device_event ctx w v =
 		match ev with
 		| Rtc _ | IntMessage _ | BackThread _ | BackEject -> assert false
 		| Backend state  ->
-			let oldstate = devstate.backstate in
+			let _ (* oldstate *) = devstate.backstate in
 			devstate.backstate <- state;
 		| Frontend state ->
-			let oldstate = devstate.frontstate in
+			let _ (* oldstate *) = devstate.frontstate in
 			devstate.frontstate <- state;
 		| BackShutdown ->
 			ctx.callback_devices ctx domid (DevShutdownDone (ty, devid))