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fix: resolve DNS on macOS (ReadU64 dropped pointer bits above 4 GB) #21

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Merged
funlang merged 1 commit into from
Oct 19, 2026
Merged

fix: resolve DNS on macOS (ReadU64 dropped pointer bits above 4 GB) #21

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13 changes: 10 additions & 3 deletions fun/lib/lib-winsock-unx.fun
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Original file line number Diff line number Diff line change
Expand Up @@ -102,6 +102,7 @@ var _shutdown = LibC().getapi('shutdown', 'ii:i');
var _close = LibC().getapi('close', 'i:i');
var _poll = LibC().getapi('poll', 'iii:i');
var _memcpy = LibC().getapi('memcpy', 'ppn:p');
var _strtoull = LibC().getapi('strtoull', 'pii:l'); // pointer-width reads, see ReadU64
// errno accessor: glibc has __errno_location(), Darwin has __error().
var _errno_loc = LibC().getapi(DyLib('__errno_location', '__error'), ':p');
var _strerror = LibC().getapi('strerror', 'i:s');
Expand All @@ -125,10 +126,16 @@ fun ErrMsg()
end fun;

// read one pointer-width (8-byte) little-endian value at byte offset off.
// str2int only reads 4 bytes, so assemble the high half explicitly.
// Fun's arithmetic is 32-bit, so the halves cannot be combined as
// low + high * 2^32; reassemble the bytes as big-endian hex text instead and
// parse it with strtoull (the lib-proc-darwin _read64 recipe).
fun ReadU64(s, off)
var t = s.substr(off, 8);
result = t.toNum(ptr: 1) + t.substr(4).toNum(ptr: 1) * 4294967296;
var h = str2hex(s.substr(off, 8));
var big = h.substr(14,2) & h.substr(12,2) & h.substr(10,2) & h.substr(8,2)
& h.substr(6,2) & h.substr(4,2) & h.substr(2,2) & h.substr(0,2);
var tb = ' '.x(20);
('0x' & big).move(tb.toNum(-1));
result = _strtoull(tb.toNum(-1), 0, 16);
end fun;

//--------------------------------------------------------------
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