mirror of
https://github.com/logos-messaging/nim-ffi.git
synced 2026-06-20 16:29:31 +00:00
3240ac0080
5a: record {.ffiHost.} procs in a compile-time registry (FFIHostMeta /
ffiHostRegistry), populated by the macro, so generators can see host fns.
5b: the Go generator emits an idiomatic wrapper over the host C ABI:
- a single //export cgo trampoline backs every host fn; a cgo.Handle in
userData selects the Go closure;
- the closure runs on a fresh GOROUTINE so the FFI thread is never blocked
(the non-blocking contract), then answers via <lib>_host_complete by token;
- a per-host `Set<Name>(func(string) (string, error))` method registers it.
Validated end to end with `go run` (examples/host_demo): Go UseToken -> Nim
{.ffi.} handler -> await fetchToken {.ffiHost.} -> Go trampoline -> goroutine
runs the closure -> host_complete -> future resolves on the loop thread ->
"token[TOK-session]" back in Go. Timer's Go output is unchanged (no host fns);
its regenerated .h just gains the always-exported host ABI decls.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
72 lines
2.5 KiB
Nim
72 lines
2.5 KiB
Nim
## Compile-time metadata types for FFI binding generation.
|
|
## Populated by the {.ffiCtor.} and {.ffi.} macros and consumed by codegen.
|
|
|
|
type
|
|
FFIParamMeta* = object
|
|
name*: string # Nim param name, e.g. "req"
|
|
typeName*: string # Nim type name, e.g. "EchoRequest"
|
|
isPtr*: bool # true if the type is `ptr T`
|
|
|
|
FFIKind* {.pure.} = enum
|
|
FFI
|
|
CTOR
|
|
DTOR
|
|
|
|
FFIProcMeta* = object
|
|
procName*: string # e.g. "timer_echo"
|
|
libName*: string # library name, e.g. "timer"
|
|
kind*: FFIKind
|
|
libTypeName*: string # e.g. "Timer"
|
|
extraParams*: seq[FFIParamMeta] # all params except the lib param
|
|
returnTypeName*: string # e.g. "EchoResponse", "string", "pointer"
|
|
returnIsPtr*: bool # true if return type is ptr T
|
|
|
|
FFIFieldMeta* = object
|
|
name*: string # e.g. "delayMs"
|
|
typeName*: string # e.g. "int"
|
|
|
|
FFITypeMeta* = object
|
|
name*: string
|
|
fields*: seq[FFIFieldMeta]
|
|
|
|
FFIEventMeta* = object
|
|
## Library-initiated event declared with `{.ffiEvent: "wire_name".}`.
|
|
## `wireName` is the literal string the foreign side dispatches on
|
|
## (it appears in the CBOR `eventType` field, verbatim — no case
|
|
## conversion). `payloadTypeName` is the Nim type of the single
|
|
## payload parameter.
|
|
wireName*: string
|
|
nimProcName*: string
|
|
libName*: string
|
|
payloadTypeName*: string
|
|
|
|
FFIHostMeta* = object
|
|
## Host-provided function declared with `{.ffiHost.}` — the host implements
|
|
## it and a `{.ffi.}` handler awaits it. `wireName` is the snake_case name
|
|
## the host registers under. First slice: one `string` arg, `string` return;
|
|
## `argName`/`argTypeName`/`returnTypeName` carry the shape so generators can
|
|
## emit a typed wrapper.
|
|
wireName*: string
|
|
nimProcName*: string
|
|
libName*: string
|
|
argName*: string
|
|
argTypeName*: string
|
|
returnTypeName*: string
|
|
|
|
# Compile-time registries populated by the macros
|
|
var ffiProcRegistry* {.compileTime.}: seq[FFIProcMeta]
|
|
var ffiTypeRegistry* {.compileTime.}: seq[FFITypeMeta]
|
|
var ffiEventRegistry* {.compileTime.}: seq[FFIEventMeta]
|
|
var ffiHostRegistry* {.compileTime.}: seq[FFIHostMeta]
|
|
var currentLibName* {.compileTime.}: string
|
|
|
|
# Target language for binding generation; override with -d:targetLang=cpp
|
|
const targetLang* {.strdefine.} = "rust"
|
|
|
|
# Output directory for generated bindings; set with -d:ffiOutputDir=path/to/dir
|
|
const ffiOutputDir* {.strdefine.} = ""
|
|
|
|
# Nim source path (relative to outputDir) embedded in generated build files;
|
|
# set with -d:ffiSrcPath=../relative/path.nim
|
|
const ffiSrcPath* {.strdefine.} = ""
|