fix: ci failing

README.md

@@ -171,17 +171,18 @@ header shape from the library's ABI format. It carries two honest limits today:
 An `abi = c` proc whose whole signature is scalar — fixed-width integer, float,
 or bool params (a `string` return is fine, a `string` param is not) and no
 structs, handles, or pointers — dispatches through a CBOR-free scalar fast path.
-The `-d:targetLang=c_abi` generator emits real bindings for that shape: the
-wrapper passes the scalar args inline (no request struct) and adapts the
-raw-bytes reply into the same typed callback surface the flat-struct methods
-use. The CBOR-speaking targets (`c`, `cpp`, `rust`, `cddl`) have no scalar
-codegen, so under `-d:ffiGenBindings` they would omit such a proc from the
-generated bindings — and `genBindings()` fails with an error naming the
-affected procs. Resolve it by generating with `-d:targetLang=c_abi`, switching
-the proc to `abi = cbor`, adding a non-scalar param so it takes the CBOR wire
-shape, or passing `-d:ffiAllowScalarSkip` to accept the omission (the proc
-still works over the scalar fast path; it's just absent from the generated
-foreign bindings).
+The `abi = c` C header (an `abi = c` library generated with `-d:targetLang=c`)
+emits real bindings for that shape: the wrapper passes the scalar args inline
+(no request struct) and adapts the raw-bytes reply into the same typed callback
+surface the flat-struct methods use. The CBOR-speaking outputs — the CBOR C
+header and the `cpp`, `rust`, `cddl` targets — have no scalar codegen, so under
+`-d:ffiGenBindings` they would omit such a proc from the generated bindings —
+and `genBindings()` fails with an error naming the affected procs. Resolve it by
+making the whole library `abi = c` and generating C bindings, switching the proc
+to `abi = cbor`, adding a non-scalar param so it takes the CBOR wire shape, or
+passing `-d:ffiAllowScalarSkip` to accept the omission (the proc still works
+over the scalar fast path; it's just absent from the generated foreign
+bindings).
 
 ## Placement of `genBindings()`
 

ffi/codegen/c.nim

@@ -1018,7 +1018,7 @@ func abiScalarRawFnName(libType: string): string =
   ## per-method trampoline converts into the typed reply.
   return libType & "ScalarRawFn"
 
-proc abiScalarArgParams(m: FFIProcMeta): seq[string] =
+func abiScalarArgParams(m: FFIProcMeta): seq[string] =
   ## C parameters for a scalar method's args — passed inline by value, in both
   ## the raw export and the high-level wrapper (no Req struct).
   var params: seq[string] = @[]

ffi/codegen/meta.nim

@@ -34,9 +34,9 @@ type
     scalarFastPath*: bool
       ## True for an `abi = c` proc whose whole signature is scalar (see
       ## `isScalarOnly`): dispatches through the CBOR-free scalar fast path.
-      ## Only the `c_abi` generator emits foreign bindings for it (inline
-      ## scalar args + raw-bytes reply trampoline); the CBOR-speaking
-      ## generators drop it (see `bindableProcs`).
+      ## Only the `abi = c` C header emits a foreign binding for it (inline
+      ## scalar args + raw-bytes reply trampoline); every other target — and
+      ## the CBOR C header — drops it (see `bindableProcs`).
 
   FFIFieldMeta* = object
     name*: string
@@ -138,5 +138,8 @@ const ffiOutputDir* {.strdefine.} = ""
 # Nim src path override relative to outputDir (-d:ffiSrcPath); empty derives it.
 const ffiSrcPath* {.strdefine.} = ""
 
-# When true, scalar-only `abi = c` procs are silently omitted rather than failing the build. Off by default so the drop is loud; see genBindings().
+# When set, scalar-only `abi = c` procs are silently omitted from bindings
+# generated by targets without scalar codegen (every target except the
+# `abi = c` C header) instead of failing the build. Off by default so the drop
+# is loud; see genBindings().
 const ffiAllowScalarSkip* {.booldefine.} = false

ffi/internal/ffi_macro.nim

@@ -1519,9 +1519,10 @@ macro ffiEvent*(args: varargs[untyped]): untyped =
   return generated
 
 proc reportScalarFastPathDrops(procs: seq[FFIProcMeta]) {.compileTime.} =
-  ## Only the `c_abi` generator emits foreign bindings for scalar-fast-path
-  ## procs; every other target drops them. Fail loudly, naming them, unless
-  ## `-d:ffiAllowScalarSkip` opts into the silent omission (then just hint).
+  ## Only the `abi = c` C header emits foreign bindings for scalar-fast-path
+  ## procs; every other target (and the CBOR C header) drops them. Fail loudly,
+  ## naming them, unless `-d:ffiAllowScalarSkip` opts into the silent omission
+  ## (then just hint).
   var skipped: seq[string] = @[]
   for p in procs:
     if p.scalarFastPath:
@@ -1537,11 +1538,12 @@ proc reportScalarFastPathDrops(procs: seq[FFIProcMeta]) {.compileTime.} =
     return
   error(
     "genBindings: this target has no foreign-binding codegen for " &
-      "scalar-fast-path `abi = c` procs (only -d:targetLang=c_abi emits them), " &
-      "so these would be silently omitted from the generated bindings: " &
-      skipped.join(", ") & ".\n" & "Fix by one of:\n" &
-      "  - generate with -d:targetLang=c_abi, or\n" &
-      "  - switch the proc to `abi = cbor`, or\n" &
+      "scalar-fast-path `abi = c` procs, so these would be silently omitted " &
+      "from the generated bindings: " & skipped.join(", ") &
+      ".\nThey are emitted only into the `abi = c` C header (an `abi = c` " &
+      "library generated with -d:targetLang=c).\n" & "Fix by one of:\n" &
+      "  - make the library `abi = c` (declareLibrary(..., \"c\")) and generate " &
+      "C bindings, or\n" & "  - switch the proc to `abi = cbor`, or\n" &
       "  - add a non-scalar param (e.g. a struct or handle) so it takes the " &
       "CBOR wire shape, or\n" & "  - pass -d:ffiAllowScalarSkip to accept the omission."
   )
@@ -1602,14 +1604,16 @@ macro genBindings*(
       let lang = string_helpers.toLower(rawLang.strip())
       if lang.len == 0:
         continue
-      # `c_abi` is the one target with scalar-fast-path codegen, so it binds the
-      # full registry; the others drop scalar procs (loudly, unless skipped).
+      # The `abi = c` C header is the one output with scalar-fast-path codegen,
+      # so it binds the full registry. Every other target — and the CBOR C
+      # header — drops scalar procs (loudly, unless skipped).
+      let emitsScalars = lang == "c" and currentDefaultABIFormat == ABIFormat.C
       let genProcs =
-        if lang == "c_abi":
+        if emitsScalars:
           ffiProcRegistry
         else:
           bindableProcs(ffiProcRegistry)
-      if lang != "c_abi":
+      if not emitsScalars:
         reportScalarFastPathDrops(ffiProcRegistry)
       let outDir = bindingsOutputDir(lang, outputDir)
       emitBindingsFor(

ffi/internal/ffi_scalar.nim

@@ -35,7 +35,7 @@ func bindableProcs*(procs: seq[FFIProcMeta]): seq[FFIProcMeta] =
   ## The procs the CBOR-speaking foreign-binding generators emit for.
   ## Scalar-fast-path procs are dropped: their C export takes inline scalar
   ## args, not the CBOR `(reqCbor, reqCborLen)` shape those backends assume, so
-  ## emitting a CBOR caller for them would be wrong. Only the `c_abi` generator
+  ## emitting a CBOR caller for them would be wrong. Only the `abi = c` C header
   ## has scalar codegen and binds the full registry (see genBindings()).
   var kept: seq[FFIProcMeta] = @[]
   for p in procs:

tests/unit/fixtures/scalar_skip_fixture.nim

@@ -1,8 +1,8 @@
-## Compile fixture for the scalar-fast-path genBindings() behavior (see
-## tests/unit/test_scalar_skip_gen.nim). Under `-d:ffiGenBindings` only the
-## `c_abi` target has foreign-binding codegen for the scalar `abi = c` proc
-## below; any other target must fail — unless `-d:ffiAllowScalarSkip` is
-## passed, which downgrades the drop to a hint.
+## Compile fixture for the scalar-fast-path drop error (see
+## tests/unit/test_scalar_skip_gen.nim). This is a CBOR-default library with one
+## stray scalar `abi = c` proc, so no target can emit a binding for it: under
+## `-d:ffiGenBindings` genBindings() must fail — unless `-d:ffiAllowScalarSkip`
+## is passed, which downgrades the drop to a hint.
 
 import ffi, chronos
 
@@ -20,8 +20,8 @@ proc scalarskip_create*(cfg: SkipConfig): Future[Result[SkipLib, string]] {.ffiC
 proc scalarskip_add*(
     lib: SkipLib, a: int, b: int
 ): Future[Result[int, string]] {.ffi: "abi = c".} =
-  ## All-scalar signature: dispatches through the CBOR-free fast path; only the
-  ## `c_abi` target generates a foreign binding for it.
+  ## All-scalar signature: dispatches through the CBOR-free fast path. In this
+  ## CBOR-default library no target can emit a foreign binding for it.
   return ok(lib.base + a + b)
 
 genBindings()

tests/unit/test_scalar_skip_gen.nim

@@ -1,12 +1,12 @@
-## Drives the scalar-fast-path genBindings() behavior end to end: compiles
-## `fixtures/scalar_skip_fixture.nim` (a library with an all-scalar `abi = c`
-## proc) with `-d:ffiGenBindings` and asserts a CBOR-speaking target
-## (`targetLang=c`) fails loudly, `-d:ffiAllowScalarSkip` downgrades the drop
-## to a clean build, and `targetLang=c_abi` needs no skip at all — it emits a
-## real binding for the scalar proc.
+## Drives the scalar-fast-path drop error end to end: compiles
+## `fixtures/scalar_skip_fixture.nim` (a CBOR-default library with a stray
+## all-scalar `abi = c` proc) with `-d:ffiGenBindings` and asserts genBindings()
+## fails loudly, and that `-d:ffiAllowScalarSkip` downgrades the drop to a clean
+## build. The positive path — the `abi = c` C header emitting a real scalar
+## binding — is covered by test_c_abi_codegen and the echo c_abi e2e.
 ##
 ## The fixture is compiled in a child `nim check` (search paths and compiler
-## captured at compile time) so an expected failure is observed as a test
+## captured at compile time) so its expected failure is observed as a test
 ## assertion, not this file's own compile error.
 
 import std/[os, osproc, strutils, compilesettings]
@@ -17,15 +17,14 @@ const
   nimExe = getCurrentCompilerExe()
   ffiSearchPaths = querySettingSeq(searchPaths)
 
-proc genFixture(
-    lang: string, extraDefs: seq[string], outDir: string
-): tuple[output: string, exitCode: int] =
+proc genFixture(extraDefs: seq[string]): tuple[output: string, exitCode: int] =
+  let outDir = getTempDir() / "ffi_scalar_skip_out"
   let cacheDir = getTempDir() / "ffi_scalar_skip_cache"
   createDir(outDir)
   var cmd = quoteShell(nimExe) & " check --hints:off --warnings:off"
   for p in ffiSearchPaths:
     cmd.add(" --path:" & quoteShell(p))
-  cmd.add(" -d:ffiGenBindings -d:targetLang=" & lang)
+  cmd.add(" -d:ffiGenBindings -d:targetLang=c")
   cmd.add(" -d:ffiOutputDir=" & quoteShell(outDir))
   for d in extraDefs:
     cmd.add(" " & d)
@@ -34,26 +33,14 @@ proc genFixture(
   execCmdEx(cmd)
 
 suite "scalar-fast-path drop is loud under -d:ffiGenBindings":
-  test "a CBOR target errors and names the dropped scalar proc":
-    let (output, code) = genFixture("c", @[], getTempDir() / "ffi_scalar_skip_out_c")
+  test "genBindings errors and names the dropped scalar proc":
+    let (output, code) = genFixture(@[])
     check code != 0
     check output.contains("scalarskip_add")
     check output.contains("scalar-fast-path")
-    check output.contains("targetLang=c_abi")
     check output.contains("-d:ffiAllowScalarSkip")
 
   test "-d:ffiAllowScalarSkip downgrades the drop to a clean build":
-    let (output, code) = genFixture(
-      "c", @["-d:ffiAllowScalarSkip"], getTempDir() / "ffi_scalar_skip_out_c_skip"
-    )
-    check code == 0
-    check not output.contains("Error")
-
-  test "targetLang=c_abi needs no skip: the scalar proc has real codegen":
-    # `nim check` runs genBindings() but VM file writes are skipped, so this
-    # asserts the clean build only; the emitted wrapper text is covered by
-    # test_c_abi_codegen and the checked-in echo c_abi bindings.
-    let (output, code) =
-      genFixture("c_abi", @[], getTempDir() / "ffi_scalar_skip_out_c_abi")
+    let (output, code) = genFixture(@["-d:ffiAllowScalarSkip"])
     check code == 0
     check not output.contains("Error")