Re: [Libguestfs] [libnbd PATCH v4 03/25] generator: Support Extent64 arg in C code

See the earlier commit "Add Extent64 arg type" for rationale in supporting a new generator arg type. This patch adds the C bindings for use of Extent64: it exposes a new 'struct nbd_extent' in <libnbd.h>, as well as the code to generate the C bindings for passing an extent64_closure once a new API uses the type in an upcoming patch. Note that 'struct nbd_block_descriptor_64' in lib/nbd-protocol.h is exactly the same as what we want to use in C. But it is easier to stick a new public type in <libnbd.h> than to figure out how to expose just part of a header we only want to use internally, and leaves us free to alter nbd-protocol.h (which is shared with nbdkit) without affecting public API. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- v4: split out of larger patch [Laszlo] --- generator/API.mli | 2 +- generator/C.ml | 12 ++++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/generator/API.mli b/generator/API.mli index 80633018..96626c9b 100644 --- a/generator/API.mli +++ b/generator/API.mli @@ -52,7 +52,7 @@ and | BytesPersistOut of string * string | Closure of closure (** function pointer + void *opaque *) | Enum of string * enum (** enum/union type, int in C *) -| Extent64 of string (** extent descriptor *) +| Extent64 of string (** extent descriptor, struct nbd_extent in C *)

| Fd of string (** file descriptor *) | Flags of string * flags (** flags, uint32_t in C *) | Int of string (** small int *) diff --git a/generator/C.ml b/generator/C.ml index 606ba1e0..e5a2879b 100644 --- a/generator/C.ml +++ b/generator/C.ml @@ -308,6 +308,11 @@ and pr "%s, " n; if types then pr "size_t "; pr "%s" len + | CBArrayAndLen (Extent64 n, len) -> + if types then pr "nbd_extent *"; + pr "%s, " n; + if types then pr "size_t "; + pr "%s" len | CBArrayAndLen _ -> assert false | CBBytesIn (n, len) -> if types then pr "const void *"; @@ -488,6 +493,13 @@ let pr "extern int nbd_get_errno (void);\n"; pr "#define LIBNBD_HAVE_NBD_GET_ERRNO 1\n"; pr "\n"; + pr "/* This is used in the callback for nbd_block_status_64.\n"; + pr " */\n"; + pr "typedef struct {\n"; + pr " uint64_t length;\n"; + pr " uint64_t flags;\n"; + pr "} nbd_extent;\n"; + pr "\n"; print_closure_structs (); List.iter ( fun (name, { args; optargs; ret }) ->