similar to: [libnbd PATCH] generator: Let nbd_aio_get_direction return unsigned

For now, there is no change to the generated code (although the man pages are slightly improved), but this will make it easier for later patches to improve OCaml and Golang bindings so that set/get pairs are typed symmetrically. --- generator/API.ml | 16 ++++++++++------ generator/API.mli | 2 ++ generator/C.ml | 20 ++++++++++++-------- generator/GoLang.ml | 13 ++++++++++++-

If we accept that callbacks will never handle the full range of parameters then we can simplify the generator quite a bit by using a special type for closure args vs normal method args. This removes many asserts and quite a bit of unreachable code (eg. Python code for handling ArrayAndLen in normal methods that was never used). The output of the generator after this commit should be identical.

This is just a basic ugly support, not meant to be pushed (at least for now). There is quite a lot missing, but there is an example which shows that it really works. And valgrind reports that all allocations were freed. The way the code is generated is also not nice, I wish there was more code actually written in some files and not generated by the generator (as much hard-coded static strings as

Previously errors caused a RuntimeException to be raised. This commit defines a custom exception (nbd.Error) which has two parameters, the required error string, and the optional errno (which may be 0 if unavailable). For example: $ ./run nbdsh -c 'h.pread(0, 0)' Traceback (most recent call last): File "/usr/lib64/python3.7/runpy.py", line 193, in _run_module_as_main

Previously errors caused a RuntimeException to be raised. This commit defines a custom exception (nbd.Error) which has two parameters, the required error string, and the optional errno (which may be 0 if unavailable). For example: $ ./run nbdsh -c 'h.pread(0, 0)' Traceback (most recent call last): File "/usr/lib64/python3.7/runpy.py", line 193, in _run_module_as_main

In libguestfs generator we have the concept of optargs which is different from plain arguments. These are mapped to optional arguments in languages that support them such as Python. This commit adds a new concept of optargs. At the moment it is simply limited to handling the optional (in some bindings) flags parameter which is used to handle the NBD_CMD_FLAG_* flags. If present, the old Flags

Inspection of the generated code showed several places where we did not release references on all error paths. In particular, switching things to always jump to an out: label, even when the underlying C function cannot fail, makes it easier to clean up when the user passes wrong types to a function call. One of the easiest triggers without this patch was this one-liner: $ nbdsh -c

In a future commit we want to add (non-optional) Flags arg. As a step to doing this, generalize OFlags so it's not tied to just NBD_CMD_FLAG_*. This does not change the C API. It does introduce a small change to the OCaml API -- putting related flags into a submodule, basically renaming them. Note we don't provide guarantees for non-C APIs. --- generator/generator

In preparation for closure lifetimes, split up the Closure so it no longer describes a list of closures, but a single callback. This changes the API because functions which take 2 or more closures now pass a separate user_data for each one. --- docs/libnbd.pod | 3 +- examples/strict-structured-reads.c | 2 +- generator/generator | 760

[RFC because generated OCaml code needs the same treatment, but I ran out of time to play with that. At least 'make -C python check' passes, although coverage is not complete yet, as there is no python/t/5XX-pread-structured-callback.py...] [Also RFC because I'm not sure if the use of a record type for 'callback' is the best approach or most idiomatic OCaml - but hey, it

On Sat, Sep 05, 2020 at 08:40:58PM -0500, Eric Blake wrote: > diff --git a/generator/API.mli b/generator/API.mli > index 712e837..e45b5c0 100644 > --- a/generator/API.mli > +++ b/generator/API.mli > @@ -78,6 +78,8 @@ and ret = > | RString (** return a newly allocated string, > caller frees, NULL for error *) > | RUInt

--- generator/GoLang.ml | 336 +++++++++++++++++- .../libnbd/libnbd_200_connect_command_test.go | 35 ++ 2 files changed, 367 insertions(+), 4 deletions(-) diff --git a/generator/GoLang.ml b/generator/GoLang.ml index 1b8f20b..e5fb97c 100644 --- a/generator/GoLang.ml +++ b/generator/GoLang.ml @@ -23,6 +23,304 @@ open Printf open API open Utils +let go_name_of_arg =

On 9/7/20 9:13 AM, Richard W.M. Jones wrote: >> +++ b/generator/C.ml >> @@ -66,15 +66,15 @@ let errcode_of_ret = >> function >> | RBool | RErr | RFd | RInt | RInt64 | RCookie -> Some "-1" >> | RStaticString | RString -> Some "NULL" >> - | RUInt -> None (* errors not possible *) >> + | RUInt | REnum (_) | RFlags

On Mon, Sep 07, 2020 at 09:38:15AM -0500, Eric Blake wrote: > On 9/7/20 9:13 AM, Richard W.M. Jones wrote: > > >>+++ b/generator/C.ml > >>@@ -66,15 +66,15 @@ let errcode_of_ret = > >> function > >> | RBool | RErr | RFd | RInt | RInt64 | RCookie -> Some "-1" > >> | RStaticString | RString -> Some "NULL" >

An optional Closure parameter, but otherwise works the same way as Closure. --- generator/generator | 57 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 46 insertions(+), 11 deletions(-) diff --git a/generator/generator b/generator/generator index 8cf95b6..8f15786 100755 --- a/generator/generator +++ b/generator/generator @@ -867,6 +867,7 @@ and arg = | UInt32 of string

We were previously generating one instance of the Python closure wrapper per (function * Closure arg). However these wrappers didn't actually differ across functions. We can therefore save a lot of code by only generating one wrapper per closure globally. This reduces the amount of generated code by nearly 25%. Before and after: $ wc -l python/methods.c 3275 python/methods.c $ wc -l

An optional Closure parameter, but otherwise works the same way as Closure. --- generator/generator | 54 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 44 insertions(+), 10 deletions(-) diff --git a/generator/generator b/generator/generator index 01da1c3..3add9a4 100755 --- a/generator/generator +++ b/generator/generator @@ -867,6 +867,7 @@ and arg = | UInt32 of string

A Closure is a list of (usually one, but can be more) closures. In C there is also a singe ‘void *user_data’ parameter which is passed by the caller into the function and through as the first parameter of each callback invocation. By grouping the previously separate Opaque and Callback* parameters together we can avoid the awkward situation where we have to scan through the argument list to try

On 8/13/19 10:12 AM, Richard W.M. Jones wrote: > An optional Closure parameter, but otherwise works the same way as > Closure. > --- > generator/generator | 57 ++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 46 insertions(+), 11 deletions(-) > > @@ -4394,6 +4399,16 @@ let print_python_binding name { args; optargs; ret; may_set_error } = > ) args; >

h.nbd_connect_command was leaking a python object per parameter, and also leaks memory on failure. In fact, it was possible to segfault on something as trivial as: nbdsh -c 'h.connect_command(["true",1])' h.nbd_pread was leaking a read buffer on every single synchronous read. My previous patch to address closure callbacks had a bug in h.nbd_pread_structured and similar: if the