swig: replace hand-written accessor wrappers with auto-generated #defines#3304
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igaw merged 1 commit intolinux-nvme:masterfrom Apr 22, 2026
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…ines SWIG generates accessor names as libnvme_STRUCT_MEMBER_get/set() but libnvme exports them as libnvme_STRUCT_get/set_MEMBER(). Previously nvme.i bridged this gap with ~35 hand-written C wrapper functions (~130 lines of boilerplate) that had to be updated manually whenever new accessors were added to the library. Add generate-swig-accessors.py, a post-processing script that reads the accessor header files produced by generate-accessors.py (accessors.h and accessors-fabrics.h, covering both common and fabrics structs) and emits nvme-swig-accessors.i containing one #define per accessor: #define libnvme_ctrl_name_get libnvme_ctrl_get_name Parsing the .h files (not the .ld version scripts) ensures the output is always in sync even before the .ld section labels are manually bumped. Object-like macros are used rather than function-like macros since the call arguments follow naturally after macro expansion. Add a new update-swig-accessors run_target in meson.build and extend the update-accessors alias to include it. Replace the hand-written wrapper blocks in nvme.i with %include "nvme-swig-accessors.i". The four bridges that cannot be auto-generated (virtual member names or !accessors:none annotations) are kept as #defines in a single block next to the %include. Signed-off-by: Martin Belanger <[email protected]> Assisted-by: Claude Sonnet 4.6 <[email protected]>
igaw
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Apr 22, 2026
| #define libnvme_subsystem_host_get libnvme_subsystem_get_host | ||
| #define libnvme_ctrl_state_get libnvme_ctrl_get_state | ||
| #define libnvme_ctrl_subsystem_get libnvme_ctrl_get_subsystem | ||
| #define libnvme_ctrl_address_get libnvme_ctrl_get_traddr |
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I am trying to figure out if the traddr vs address name is going to bite us.
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From what I can tell just looking at struct libnvme_ctrl (private.h, line 264), address and traddr are not the same thing. Or are they?
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address got renamed to traddr to match with the kernel argument names. I suppose we should remove address from the Python binding.
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Thanks! |
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swig: auto-generate #define bridges for accessors
SWIG uses a naming convention (
libnvme_STRUCT_MEMBER_get/set) that differs from the libnvme C API convention (libnvme_STRUCT_get/set_MEMBER). Until now this mismatch was papered over by ~35 hand-written C wrapper functions insidenvme.i— one thin shim per accessor that did nothing but call the real function.This commit replaces all those shims with automatically generated C preprocessor
#defineobject-like macros. Because the macros have no parameter list, the arguments flow through naturally, so no wrapper function body is needed at all.What changed
New script:
libnvme/tools/generator/generate-swig-accessors.pyPost-processing step that reads
accessors.handaccessors-fabrics.h(already kept up to date bygenerate-accessors.py) and emitslibnvme/libnvme/nvme-swig-accessors.i. It uses a non-greedy regex to split each accessor name at the first_get_/_set_occurrence so that multi-word member names (e.g.dhchap_host_key) and long struct prefixes (e.g.libnvmf_discovery_args) are handled correctly. Output is only rewritten when the content changes, avoiding spurious mtime updates.Updated:
libnvme/tools/generator/meson.buildupdate-swig-accessorsrun-target that invokes the new script.update-accessorsalias so thatmeson compile -C <build-dir> update-accessorsregenerates all three artefact sets in one shot.New generated file:
libnvme/libnvme/nvme-swig-accessors.iContains one
#defineper accessor for every struct annotated inprivate.handprivate-fabrics.h, grouped by struct and with the third column vertically aligned within each group for readability.Updated:
libnvme/libnvme/nvme.iAdded
%include "nvme-swig-accessors.i"(alongside the existing%include "exception.i") so SWIG picks up all the bridges automatically.Removed all four hand-written wrapper
%{ %}blocks (host, subsystem, ctrl, ns) — 168 lines deleted.Kept four
#definebridges that cannot be auto-generated (virtual Python property names or!accessors:noneannotations), consolidated into the main%{ %}preamble with a comment explaining why each one exists:Result
New accessors added to libnvme (via
private.hannotations) now automatically appear in the Python bindings after runningmeson compile -C <build-dir> update-accessors— zero manual maintenance ofnvme.irequired.