[Libguestfs] [PATCH] golang: make API idiomatic so that functions return (<val>, error)
Go API functions returned (<val>, *GuestfsError) that made
code like this fail to build:
n, err := os.Stdin.Read(buf)
if err != nil {
log.Fatal(err)
}
n, err = g.Pwrite_device(dev, buf[:n], off)
...
As err should be of error (interface) type as of the stdlib call,
and should be of *GuestfsError type as of the libguestfs call.
The concrete error value that libguestfs functions return can be
a *GuestfsError, but the function signature should have (<val>, error)
as return value.
---
generator/golang.ml | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/generator/golang.ml b/generator/golang.ml
index bd09ae9cf..e11967d57 100644
--- a/generator/golang.ml
+++ b/generator/golang.ml
@@ -114,6 +114,11 @@ func (e *GuestfsError) String() string {
}
}
+/* Implement the error interface */
+func (e *GuestfsError) Error() string {
+ return e.String()
+}
+
func get_error_from_handle (g *Guestfs, op string) *GuestfsError {
// NB: DO NOT try to free c_errmsg!
c_errmsg := C.guestfs_last_error (g.g)
@@ -322,24 +327,24 @@ func return_hashtable (argv **C.char) map[string]string {
(* Return type. *)
let noreturn =
match ret with
- | RErr -> pr " *GuestfsError"; ""
- | RInt _ -> pr " (int, *GuestfsError)"; "0, "
- | RInt64 _ -> pr " (int64, *GuestfsError)"; "0, "
- | RBool _ -> pr " (bool, *GuestfsError)"; "false, "
+ | RErr -> pr " error"; ""
+ | RInt _ -> pr " (int, error)"; "0, "
+ | RInt64 _ -> pr " (int64, error)"; "0, "
+ | RBool _ -> pr " (bool, error)"; "false, "
| RConstString _
- | RString _ -> pr " (string, *GuestfsError)"; "\"\",
"
- | RConstOptString _ -> pr " (*string, *GuestfsError)"; "nil,
"
- | RStringList _ -> pr " ([]string, *GuestfsError)"; "nil,
"
+ | RString _ -> pr " (string, error)"; "\"\", "
+ | RConstOptString _ -> pr " (*string, error)"; "nil, "
+ | RStringList _ -> pr " ([]string, error)"; "nil, "
| RStruct (_, sn) ->
let sn = camel_name_of_struct sn in
- pr " (*%s, *GuestfsError)" sn;
+ pr " (*%s, error)" sn;
sprintf "&%s{}, " sn
| RStructList (_, sn) ->
let sn = camel_name_of_struct sn in
- pr " (*[]%s, *GuestfsError)" sn;
+ pr " (*[]%s, error)" sn;
"nil, "
- | RHashtable _ -> pr " (map[string]string, *GuestfsError)";
"nil, "
- | RBufferOut _ -> pr " ([]byte, *GuestfsError)"; "nil, "
in
+ | RHashtable _ -> pr " (map[string]string, error)"; "nil,
"
+ | RBufferOut _ -> pr " ([]byte, error)"; "nil, " in
(* Body of the function. *)
pr " {\n";
--
2.25.1