Files
sx/src/ir/host_ffi.zig
agra dc51c4b5bf refactor(ffi-linkage): Phase 9.3-src — purge 'foreign' from src/ comments + a user-facing diagnostic
Reword every 'foreign' comment to the extern/runtime-class vocabulary matching the
renamed identifiers (foreign call→extern call, foreign class→runtime class, foreign
path→runtime path, the #foreign-literal comment mentions → extern, etc.). Also fixes
two USER-FACING issues: the 'expected … #foreign … after type annotation' parse error
no longer advertises the removed keyword, and the Android 'no #jni_main' help
diagnostic now shows '#jni_class(…) extern' instead of the rejected '#foreign
#jni_class'. Removed the now-dead prefix-#foreign-vs-postfix conflict branch in
parseRuntimeClassDecl (the caller rejects #foreign before it runs).

src/ now contains 'foreign' ONLY in the hash_foreign token machinery + its 4
rejection messages — the deprecation mechanism (kept per the 9.0 recommendation; the
message MUST name #foreign to guide migration). Snapshot-neutral; suite green
(646 corpus / 444 unit, 0 failed).
2026-06-15 09:35:00 +03:00

156 lines
10 KiB
Zig

//! Host FFI dispatch for the IR interpreter.
//!
//! When the interpreter encounters a call to an extern function during `#run`
//! (or post-link interpretation), it has no body to walk. This module
//! `dlsym`s the symbol from the host's already-loaded dylibs (libc, libSystem,
//! kernel32, whatever the OS provides) and calls it via an arity-switched
//! cdecl function pointer.
//!
//! Limits:
//! * Up to 8 cdecl-passed arguments. Beyond that, return error.
//! * All arguments are marshalled to / from `usize`. Pointer-sized integers,
//! pointers, null-terminated strings, and booleans are supported; floats,
//! aggregates passed by value, and varargs are not.
//! * Return value can be void, integer (i64), pointer (usize), or boolean.
const std = @import("std");
const RTLD_DEFAULT: ?*anyopaque = @ptrFromInt(@as(usize, @bitCast(@as(isize, -2))));
extern "c" fn dlsym(handle: ?*anyopaque, name: [*:0]const u8) ?*anyopaque;
/// Look up an extern symbol in the host's loaded image. Returns null if not
/// found.
pub fn lookupSymbol(allocator: std.mem.Allocator, name: []const u8) !?*anyopaque {
const name_z = try allocator.allocSentinel(u8, name.len, 0);
defer allocator.free(name_z);
@memcpy(name_z[0..name.len], name);
return dlsym(RTLD_DEFAULT, name_z.ptr);
}
/// Call a cdecl symbol that returns `i64`. Args are pre-marshalled to `usize`.
pub fn callIntRet(symbol: *anyopaque, args: []const usize) !i64 {
return switch (args.len) {
0 => @as(*const fn () callconv(.c) i64, @ptrCast(@alignCast(symbol)))(),
1 => @as(*const fn (usize) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0]),
2 => @as(*const fn (usize, usize) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, usize, usize) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, usize, usize, usize) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
5 => @as(*const fn (usize, usize, usize, usize, usize) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4]),
6 => @as(*const fn (usize, usize, usize, usize, usize, usize) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5]),
7 => @as(*const fn (usize, usize, usize, usize, usize, usize, usize) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5], args[6]),
8 => @as(*const fn (usize, usize, usize, usize, usize, usize, usize, usize) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7]),
else => return error.TooManyArgs,
};
}
/// Call a cdecl symbol that returns a pointer (or any pointer-sized value).
pub fn callPtrRet(symbol: *anyopaque, args: []const usize) !usize {
return switch (args.len) {
0 => @as(*const fn () callconv(.c) usize, @ptrCast(@alignCast(symbol)))(),
1 => @as(*const fn (usize) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0]),
2 => @as(*const fn (usize, usize) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, usize, usize) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, usize, usize, usize) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
5 => @as(*const fn (usize, usize, usize, usize, usize) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4]),
6 => @as(*const fn (usize, usize, usize, usize, usize, usize) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5]),
7 => @as(*const fn (usize, usize, usize, usize, usize, usize, usize) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5], args[6]),
8 => @as(*const fn (usize, usize, usize, usize, usize, usize, usize, usize) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7]),
else => return error.TooManyArgs,
};
}
/// Call a cdecl symbol with void return.
pub fn callVoidRet(symbol: *anyopaque, args: []const usize) !void {
switch (args.len) {
0 => @as(*const fn () callconv(.c) void, @ptrCast(@alignCast(symbol)))(),
1 => @as(*const fn (usize) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0]),
2 => @as(*const fn (usize, usize) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, usize, usize) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, usize, usize, usize) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
5 => @as(*const fn (usize, usize, usize, usize, usize) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4]),
6 => @as(*const fn (usize, usize, usize, usize, usize, usize) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5]),
7 => @as(*const fn (usize, usize, usize, usize, usize, usize, usize) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5], args[6]),
8 => @as(*const fn (usize, usize, usize, usize, usize, usize, usize, usize) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7]),
else => return error.TooManyArgs,
}
}
// ── Variadic cdecl dispatch ─────────────────────────────────────────
// For extern functions declared with `args: ..T` (C-variadic, e.g.
// libc `open(path, flags, ...)`). The trailing args must be passed
// through the C-variadic ABI — arm64 places them on the stack rather
// than in argument registers. Calling a variadic function as if it
// were fixed-arity puts the mode/etc. in the wrong register and the
// callee reads garbage.
//
// The dispatch is keyed by (fixed_count, total_args). `fixed_count`
// is the number of declared (non-variadic) params; trailing
// `total_args - fixed_count` slots are the variadic tail. The Zig
// function-pointer types use `...` so the compiler emits
// proper-variadic calls.
pub fn callIntRetVar(symbol: *anyopaque, fixed: usize, args: []const usize) !i64 {
if (args.len < fixed) return error.TooFewArgs;
// Special-case the shapes we actually use today; extend as
// needed. fixed_count > total is impossible.
return switch (fixed) {
2 => switch (args.len) {
2 => @as(*const fn (usize, usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
5 => @as(*const fn (usize, usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4]),
else => return error.TooManyArgs,
},
1 => switch (args.len) {
1 => @as(*const fn (usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0]),
2 => @as(*const fn (usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
5 => @as(*const fn (usize, ...) callconv(.c) i64, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3], args[4]),
else => return error.TooManyArgs,
},
else => return error.UnsupportedVariadicArity,
};
}
pub fn callPtrRetVar(symbol: *anyopaque, fixed: usize, args: []const usize) !usize {
if (args.len < fixed) return error.TooFewArgs;
return switch (fixed) {
2 => switch (args.len) {
2 => @as(*const fn (usize, usize, ...) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, usize, ...) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, usize, ...) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
else => return error.TooManyArgs,
},
1 => switch (args.len) {
1 => @as(*const fn (usize, ...) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0]),
2 => @as(*const fn (usize, ...) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, ...) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, ...) callconv(.c) usize, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
else => return error.TooManyArgs,
},
else => return error.UnsupportedVariadicArity,
};
}
pub fn callVoidRetVar(symbol: *anyopaque, fixed: usize, args: []const usize) !void {
if (args.len < fixed) return error.TooFewArgs;
switch (fixed) {
2 => switch (args.len) {
2 => @as(*const fn (usize, usize, ...) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, usize, ...) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, usize, ...) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
else => return error.TooManyArgs,
},
1 => switch (args.len) {
1 => @as(*const fn (usize, ...) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0]),
2 => @as(*const fn (usize, ...) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1]),
3 => @as(*const fn (usize, ...) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2]),
4 => @as(*const fn (usize, ...) callconv(.c) void, @ptrCast(@alignCast(symbol)))(args[0], args[1], args[2], args[3]),
else => return error.TooManyArgs,
},
else => return error.UnsupportedVariadicArity,
}
}