Files
sx/examples/101-ffi-medium-struct.sx
agra 3855f2351e ffi: move test-companion .c/.h next to their .sx (drop vendors/ namespace)
vendors/ is a third-party namespace (stb_image, kb_text_shape, etc.);
test fixtures don't belong there. The .c/.h companion files for the
Phase-0 FFI baselines now sit alongside the .sx that drives them in
examples/, with matching basenames:

  examples/ffi-01-primitives.{sx,c,h}    <- was vendors/ffi_primitives/
  examples/ffi-02-small-struct.{sx,c,h}  <- was vendors/ffi_structs/
  examples/ffi-03-large-struct.{sx,c,h}  <- was vendors/ffi_large_struct/
  examples/ffi-04-fp-struct.{sx,c,h}     <- was vendors/ffi_fp_struct/
  examples/ffi-05-string-args.{sx,c,h}   <- was vendors/ffi_strings/
  examples/ffi-06-callback.{sx,c,h}      <- was vendors/ffi_callback/
  examples/101-ffi-medium-struct.{sx,c}  <- was vendors/ffi_medium_struct/

`#source` / `#include` paths in the .sx files become bare filenames
(no prefix) since imports.zig's base_dir resolution finds them
relative to the importing .sx file's directory.

`library/vendors/sx_ffi_resolve_test/` stays put — that one's the
whole point: regression coverage for the stdlib-search branch of
the resolution chain, so it must live where ONLY that branch can
find it.

94/94 regression tests pass.
2026-05-19 11:54:36 +03:00

34 lines
1.1 KiB
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// 16-byte integer-only struct passed by value through `#foreign`.
//
// emit_llvm.zig's `abiCoerceParamType` routes 9..16-byte non-HFA
// structs through `[2 x i64]` for register-pair passing on AAPCS64 /
// SysV AMD64. The call-site side loads the sx struct as `{ i64, i64 }`,
// so the verifier needs a memory-bitcast bridge in both directions
// (`abi.struct2arr` on the way in, `abi.arr2struct` on the way back).
//
// Different ABI path from 8-byte register-pair structs (coerce to
// i64), HFAs at the same total size (Vec4f stays a struct), and
// >16-byte aggregates (passed via pointer + byval).
//
// This file was originally filed as issue-0036 (LLVM verifier
// failure repro). Promoted to a focused feature example once the
// emit_llvm.zig coerceArg branches landed.
#import "modules/std.sx";
#import c {
#source "101-ffi-medium-struct.c";
};
Pair64 :: struct { a: s64; b: s64; }
ffi_pair64_swap :: (p: Pair64) -> Pair64 #foreign;
main :: () -> s32 {
p : Pair64 = .{ a = 1, b = 2 };
q := ffi_pair64_swap(p);
print("swap = ({}, {})\n", q.a, q.b);
print("ok = {}\n", q.a == 2 and q.b == 1);
0;
}