nim-ffi/ffi.nimble
Ivan FB 725a7b6551
feat(codegen): native (non-CBOR) C++ generator — core
A native C++ binding generator (`cpp_native.nim`), the C++ counterpart of the C
and Go native paths and companion to the CBOR `cpp.nim`. It emits
`<lib>_native.hpp`: an idiomatic C++ struct + `toC`/`fromC` per `{.ffi.}` type,
and a `<Lib>Node` class whose methods marshal typed args into / read typed
struct returns out of the native ABI (`<name>` entry points + flat C structs in
`<lib>.h`) — zero serialization. Wired into genBindings under
`targetLang=cpp` + `-d:ffiMode=native`; emits the native C header alongside so
the binding is self-contained. Task: `genbindings_cpp_native`.

First cut covers scalar/string/bool/nested-struct fields (create/version/echo);
seq/Option params are `// SKIPPED`, and native typed events are next. Filename
is `_native.hpp` for now to coexist with the CBOR `.hpp` (rename is a follow-up).

Verified end-to-end: the generated example builds and round-trips a typed
EchoResponse (`make run`).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-05-31 18:39:19 +02:00

238 lines
9.5 KiB
Nim

# ffi.nimble
version = "0.2.0"
author = "Institute of Free Technology"
description = "FFI framework with custom header generation"
license = "MIT or Apache License 2.0"
packageName = "ffi"
requires "nim >= 2.2.4"
requires "chronos"
requires "chronicles"
requires "taskpools"
requires "cbor_serialization"
const nimFlagsOrc = "--mm:orc -d:chronicles_log_level=WARN"
const nimFlagsRefc = "--mm:refc -d:chronicles_log_level=WARN"
import std/[algorithm, os, strutils]
proc discoverUnitTests(): seq[string] =
# `listFiles` returns both .nim sources and any compiled binaries left in
# the dir from prior local runs — filter to .nim so we don't run a test
# twice (and don't try to `nim c -r` a stale binary).
var names: seq[string] = @[]
for path in listFiles(thisDir() / "tests/unit"):
if path.endsWith(".nim"):
let name = path.extractFilename.changeFileExt("")
if name.startsWith("test_"):
names.add(name)
names.sort()
return names
let unitTests = discoverUnitTests()
proc runOrQuit(cmd: string) =
# Workaround for newer nimble (shipping with Nim 2.2.10+) printing the
# OSError from a failed `exec` but exiting 0, which causes CI to report
# green on actual build/test failures. Echo the command first so the log
# makes clear which step failed.
try:
exec cmd
except OSError as e:
echo "command failed: ", cmd
echo "error: ", e.msg
quit(QuitFailure)
proc sanFlags(san: string): string =
# Each --passC / --passL adds one literal flag to the C compiler / linker
# invocation — avoids any quoting ambiguity that arises from putting
# space-separated flags inside a single --passC argument.
#
# `asan-ubsan` enables LeakSanitizer too: ASan includes LSan, so leaks are
# reported when ASAN_OPTIONS=detect_leaks=1 (set by the sanitizer CI job).
case san
of "none", "":
""
of "asan-ubsan":
" --passC:-fsanitize=address,undefined" &
" --passC:-fno-sanitize-recover=all" &
" --passC:-fno-omit-frame-pointer" &
" --passC:-g" &
" --passL:-fsanitize=address,undefined"
of "tsan":
" --passC:-fsanitize=thread" &
" --passC:-fno-omit-frame-pointer" &
" --passC:-g" &
" --passC:-O1" &
" --passL:-fsanitize=thread"
else:
raise newException(ValueError, "unknown NIM_FFI_SAN: " & san)
task buildffi, "Compile the library":
exec "nim c " & nimFlagsOrc & " --app:lib --noMain ffi.nim"
task test, "Run all tests under --mm:orc and --mm:refc":
for flags in [nimFlagsOrc, nimFlagsRefc]:
for t in unitTests:
exec "nim c -r " & flags & " tests/unit/" & t & ".nim"
task test_alloc, "Run alloc unit tests under --mm:orc and --mm:refc":
exec "nim c -r " & nimFlagsOrc & " tests/unit/test_alloc.nim"
exec "nim c -r " & nimFlagsRefc & " tests/unit/test_alloc.nim"
task test_ffi, "Run FFI context integration tests under --mm:orc and --mm:refc":
exec "nim c -r " & nimFlagsOrc & " tests/unit/test_ffi_context.nim"
exec "nim c -r " & nimFlagsRefc & " tests/unit/test_ffi_context.nim"
task test_serial, "Run CBOR codec unit tests":
exec "nim c -r " & nimFlagsOrc & " tests/unit/test_serial.nim"
exec "nim c -r " & nimFlagsRefc & " tests/unit/test_serial.nim"
task test_cpp_e2e, "Build and run the C++ end-to-end tests for the timer example":
# Regenerate the C++ bindings so the suite always runs against fresh codegen.
runOrQuit "nimble genbindings_cpp"
runOrQuit "nimble genbindings_cpp_echo"
runOrQuit "cmake -S tests/e2e/cpp -B tests/e2e/cpp/build"
runOrQuit "cmake --build tests/e2e/cpp/build"
runOrQuit "ctest --test-dir tests/e2e/cpp/build --output-on-failure"
task test_sanitized, "Run all unit tests under a sanitizer (NIM_FFI_SAN) and mm (NIM_FFI_MM)":
let san = getEnv("NIM_FFI_SAN", "none")
let mm = getEnv("NIM_FFI_MM", "")
let extra = sanFlags(san)
let modes =
if mm == "orc": @[nimFlagsOrc]
elif mm == "refc": @[nimFlagsRefc]
else: @[nimFlagsOrc, nimFlagsRefc]
if san == "tsan":
let suppPath = thisDir() & "/tsan.supp"
let existing = getEnv("TSAN_OPTIONS")
if existing == "":
putEnv("TSAN_OPTIONS", "suppressions=" & suppPath)
elif "suppressions=" notin existing:
putEnv("TSAN_OPTIONS", existing & ":suppressions=" & suppPath)
for flags in modes:
for t in unitTests:
exec "nim c -r " & flags & extra & " tests/unit/" & t & ".nim"
task test_cpp_e2e_sanitized, "Build and run the C++ e2e tests with a sanitizer (NIM_FFI_SAN) and mm (NIM_FFI_MM)":
let mm = getEnv("NIM_FFI_MM", "orc")
let san = getEnv("NIM_FFI_SAN", "none")
runOrQuit "nimble genbindings_cpp"
runOrQuit "nimble genbindings_cpp_echo"
runOrQuit "cmake -S tests/e2e/cpp -B tests/e2e/cpp/build" &
" -DNIM_FFI_MM=" & mm &
" -DNIM_FFI_SANITIZER=" & san
runOrQuit "cmake --build tests/e2e/cpp/build -j"
runOrQuit "ctest --test-dir tests/e2e/cpp/build --output-on-failure"
task genbindings_example, "Generate Rust bindings for the timer example":
exec "nim c " & nimFlagsOrc & " --app:lib --noMain --nimMainPrefix:libmy_timer -d:ffiGenBindings -o:/dev/null examples/timer/timer.nim"
exec "nim c " & nimFlagsRefc & " --app:lib --noMain --nimMainPrefix:libmy_timer -d:ffiGenBindings -o:/dev/null examples/timer/timer.nim"
task genbindings_rust, "Generate Rust bindings for the timer example":
exec "nim c " & nimFlagsOrc &
" --app:lib --noMain --nimMainPrefix:libmy_timer" &
" -d:ffiGenBindings -d:targetLang=rust" &
" -d:ffiOutputDir=examples/timer/rust_bindings" &
" -d:ffiSrcPath=../timer.nim" &
" -o:/dev/null examples/timer/timer.nim"
exec "nim c " & nimFlagsRefc &
" --app:lib --noMain --nimMainPrefix:libmy_timer" &
" -d:ffiGenBindings -d:targetLang=rust" &
" -d:ffiOutputDir=examples/timer/rust_bindings" &
" -d:ffiSrcPath=../timer.nim" &
" -o:/dev/null examples/timer/timer.nim"
# `mode` selects the ABI to emit: "native", "cbor", or "both" (-d:ffiMode).
proc genC(mode: string) =
for flags in [nimFlagsOrc, nimFlagsRefc]:
exec "nim c " & flags & " --app:lib --noMain --nimMainPrefix:libmy_timer" &
" -d:ffiGenBindings -d:targetLang=c -d:ffiMode=" & mode &
" -d:ffiOutputDir=examples/timer/c_bindings -d:ffiSrcPath=../timer.nim" &
" -o:/dev/null examples/timer/timer.nim"
task genbindings_c, "Generate C bindings (native + CBOR) for the timer example":
genC("both")
task genbindings_c_native, "Generate only the native C bindings (<lib>.h)":
genC("native")
task genbindings_c_cbor, "Generate only the CBOR C bindings (<lib>_cbor.h)":
genC("cbor")
task genbindings_go, "Generate Go (cgo) bindings for the timer example":
exec "nim c " & nimFlagsOrc &
" --app:lib --noMain --nimMainPrefix:libmy_timer" &
" -d:ffiGenBindings -d:targetLang=go" &
" -d:ffiOutputDir=examples/timer/go_bindings" &
" -d:ffiSrcPath=../timer.nim" &
" -o:/dev/null examples/timer/timer.nim"
# The codegen emits compilable but not column-aligned Go; gofmt finalizes it
# (cgo struct-field alignment etc.). Skipped silently if gofmt isn't present.
if findExe("gofmt").len > 0:
exec "gofmt -w examples/timer/go_bindings/my_timer.go"
task genbindings_cddl, "Generate CDDL schema for the timer example":
exec "nim c " & nimFlagsOrc &
" --app:lib --noMain --nimMainPrefix:libtimer" &
" -d:ffiGenBindings -d:targetLang=cddl" &
" -d:ffiOutputDir=examples/timer/cddl_bindings" &
" -d:ffiSrcPath=../timer.nim" &
" -o:/dev/null examples/timer/timer.nim"
task genbindings_cpp, "Generate C++ bindings for the timer example":
exec "nim c " & nimFlagsOrc &
" --app:lib --noMain --nimMainPrefix:libmy_timer" &
" -d:ffiGenBindings -d:targetLang=cpp" &
" -d:ffiOutputDir=examples/timer/cpp_bindings" &
" -d:ffiSrcPath=../timer.nim" &
" -o:/dev/null examples/timer/timer.nim"
exec "nim c " & nimFlagsRefc &
" --app:lib --noMain --nimMainPrefix:libmy_timer" &
" -d:ffiGenBindings -d:targetLang=cpp" &
" -d:ffiOutputDir=examples/timer/cpp_bindings" &
" -d:ffiSrcPath=../timer.nim" &
" -o:/dev/null examples/timer/timer.nim"
task genbindings_cpp_native, "Generate native (non-CBOR) C++ bindings for the timer example":
exec "nim c " & nimFlagsOrc &
" --app:lib --noMain --nimMainPrefix:libmy_timer" &
" -d:ffiGenBindings -d:targetLang=cpp -d:ffiMode=native" &
" -d:ffiOutputDir=examples/timer/cpp_native_bindings" &
" -d:ffiSrcPath=../timer.nim" &
" -o:/dev/null examples/timer/timer.nim"
task genbindings_cpp_echo, "Generate C++ bindings for the echo example":
exec "nim c " & nimFlagsOrc &
" --app:lib --noMain --nimMainPrefix:libecho" &
" -d:ffiGenBindings -d:targetLang=cpp" &
" -d:ffiOutputDir=examples/echo/cpp_bindings" &
" -d:ffiSrcPath=../echo.nim" &
" -o:/dev/null examples/echo/echo.nim"
exec "nim c " & nimFlagsRefc &
" --app:lib --noMain --nimMainPrefix:libecho" &
" -d:ffiGenBindings -d:targetLang=cpp" &
" -d:ffiOutputDir=examples/echo/cpp_bindings" &
" -d:ffiSrcPath=../echo.nim" &
" -o:/dev/null examples/echo/echo.nim"
task check_bindings_rust, "Verify checked-in Rust bindings match Nim source":
exec "nimble genbindings_rust"
exec "git diff --exit-code --" &
" examples/timer/rust_bindings/Cargo.toml" &
" examples/timer/rust_bindings/build.rs" &
" examples/timer/rust_bindings/src"
task check_bindings_cpp, "Verify checked-in C++ bindings match Nim source":
exec "nimble genbindings_cpp"
exec "git diff --exit-code --" &
" examples/timer/cpp_bindings/my_timer.hpp" &
" examples/timer/cpp_bindings/CMakeLists.txt"
task check_bindings, "Verify all checked-in example bindings match Nim source":
exec "nimble check_bindings_rust"
exec "nimble check_bindings_cpp"