31715bd251
92/92 regression tests pass (+ffi-05-string-args).
Covers the four shapes that actually appear at the sx ↔ C boundary
today:
1. [:0]u8 string literal -> const char* (ffi_strlen, ffi_first_byte)
2. sx `string` value via .ptr (slice-decay branch in
coerceArg pulls the pointer)
3. [*]u8 raw buffer + length (ffi_sum_bytes, mutated via
ffi_write_byte and read back)
4. C-returned const char* (round-trips back as [*]u8)
The mutate-via-C path catches any pointer-aliasing regression — sx
allocates the fixed array `bytes : [4]u8`, passes `.ptr` to C which
writes index 1, and the sx side reads `bytes[1]` to confirm the
mutation took effect through the same memory.
50 lines
2.2 KiB
Plaintext
50 lines
2.2 KiB
Plaintext
// Phase 0 baseline (PLAN-FFI.md step 0.5): the three shapes that
|
|
// actually appear at the sx ↔ C boundary today:
|
|
//
|
|
// 1. Null-terminated `[:0]u8` — passed by `.ptr` to a `const char *`.
|
|
// 2. Raw byte buffer `[*]u8` — pointer + explicit length.
|
|
// 3. sx `string` value — coerceArg's "fat-pointer decay" branch
|
|
// pulls `.ptr` automatically for `*u8`/
|
|
// `[:0]u8` params (string is `{ptr, len}`).
|
|
// 4. Pointer return from C — round-trips back as `[*]u8` / `*u8`.
|
|
|
|
#import "modules/std.sx";
|
|
|
|
#import c {
|
|
#source "vendors/ffi_strings/ffi_strings.c";
|
|
};
|
|
|
|
ffi_strlen :: (s: [:0]u8) -> s32 #foreign;
|
|
ffi_first_byte :: (s: [:0]u8) -> s32 #foreign;
|
|
ffi_sum_bytes :: (buf: [*]u8, len: s32) -> s32 #foreign;
|
|
ffi_write_byte :: (buf: [*]u8, idx: s32, v: u8) -> void #foreign;
|
|
ffi_static_greeting :: () -> [*]u8 #foreign;
|
|
|
|
main :: () -> s32 {
|
|
// ── [:0]u8 null-terminated literal ─────────────────────────────
|
|
msg : [:0]u8 = "hello";
|
|
print("strlen(\"hello\") = {}\n", ffi_strlen(msg));
|
|
print("first_byte = {}\n", ffi_first_byte(msg));
|
|
|
|
// ── sx `string` → C `const char *` (slice-decay through coerceArg) ─
|
|
s : string = "sx string here";
|
|
print("strlen(sx string) = {}\n", ffi_strlen(xx s.ptr));
|
|
|
|
// ── [*]u8 raw buffer + length ──────────────────────────────────
|
|
bytes : [4]u8 = .[10, 20, 30, 40];
|
|
bp : [*]u8 = xx @bytes[0];
|
|
print("sum_bytes([10,20,30,40]) = {}\n", ffi_sum_bytes(bp, 4));
|
|
|
|
// ── Mutate buffer via C, read back from sx ─────────────────────
|
|
ffi_write_byte(bp, 1, 99);
|
|
print("bytes[1] after write = {}\n", bytes[1]);
|
|
|
|
// ── C returns a static string pointer; read it byte-by-byte ────
|
|
g := ffi_static_greeting();
|
|
n := ffi_strlen(xx g);
|
|
print("static greeting len = {}\n", n);
|
|
print("static greeting [0] = {}\n", g[0]);
|
|
|
|
0;
|
|
}
|