# `mix mob.regen_driver_tab`
[🔗](https://github.com/genericjam/mob_dev/blob/main/lib/mix/tasks/mob.regen_driver_tab.ex#L1)

Regenerates the per-app static-NIF table source files in
`priv/generated/driver_tab_ios.zig` and `priv/generated/driver_tab_android.zig`.

These files are linked **before** `libbeam.a` so they override BEAM's empty
built-in `erts_static_nif_tab[]`. Without them, `load_nif/2` falls back to
`dlopen`, which is broken on iOS (App Store rejects bundled `.dylibs`) and
on Android (RTLD_LOCAL hides parent's `enif_*` symbols from children).

    mix mob.regen_driver_tab              # regenerate both platforms (default: Zig)
    mix mob.regen_driver_tab --format c   # emit driver_tab_*.c instead (hand-editable C)
    mix mob.regen_driver_tab --check      # verify on-disk matches manifest, exit non-zero on drift

## Format

Zig is the default as of Phase 6a iter 4 — it uses comptime gates
instead of `#ifdef` for guarded NIFs (e.g. iOS `sqlite3_nif`
device-only), and Zig's `export` keyword produces the same C-ABI
symbols libbeam.a expects. `--format c` is still supported for
anyone who wants a hand-editable C dispatch table. Both formats
produce equivalent behavior at link time.

C NIF authors are unaffected by the default: their `c_src/<name>.c`
files compile via the usual path, and the Zig dispatch table calls
their `<name>_nif_init()` function through standard C ABI (`extern
fn <name>_nif_init() callconv(.c)`).

## Where the NIF list comes from

`MobDev.StaticNifs.default_nifs/0` baked-in defaults are merged with any
`:static_nifs` set in `mob.exs`:

    config :mob_dev,
      static_nifs: [
        %{module: :my_native, archs: [:all]}
      ]

See `MobDev.StaticNifs` for the entry schema and arch values.

## Why a Mix task and not a build-time generator

The output is committed to the app's repo so reviewers can see what's in
the static-link surface. It also lets non-Mob build tools (e.g. xcodebuild
invoked outside `mix mob.deploy`) pick up the file as plain source. The
task is fast (deterministic file generation) so re-running it on every
`mix compile` is cheap.

## Drift detection

`mob.doctor` runs `--check` mode and reports any drift between the
manifest and the on-disk files. CI can do the same.

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*Consult [api-reference.md](api-reference.md) for complete listing*