d88bdd7242
Two genuine defects behind the 0128 filing (whose original repros were
both poisoned by binding getenv, which std already declares -> *u8):
1. Re-declaring a C symbol was silent first-wins: every call through
the later declaration was typed by the older signature. Foreign
registration now dedupes — equal signatures share one FuncId,
conflicting ones are diagnosed.
2. Foreign -> string / -> ?string returns read garbage: C returns one
char*, but the LLVM signature declared the fat {ptr,i64} (len =
register garbage), and ?string was mis-declared SRET (the hidden
out-pointer landed in the callee's first arg register). cstrRetKind
now classifies such returns, declares them as plain ptr (never
sret), and the call site synthesizes {ptr, strlen} via a
branch-guarded strlen (NULL -> {null,0} / optional null), wrapping
{string, i1} for ?string.
?[:0]u8 itself resolves fine (it is ?string); the spelling works in
return, param, local, and alias positions.
Regression: examples/1221 (plain + optional non-null + NULL paths) and
examples/1172 (conflict diagnostic); both FAIL pre-fix. The extern
dedupe collapses duplicate libc decls, so affected .ir snapshots were
regenerated. zig build test 426/426; run_examples 602/602;
distribution suite 21/21.
32 lines
1.2 KiB
Plaintext
32 lines
1.2 KiB
Plaintext
// Foreign `-> [:0]u8` / `-> ?[:0]u8` returns: C hands back ONE `char *`;
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// the fat sx string is synthesized at the call boundary ({ptr, strlen};
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// NULL maps to the optional's null / an empty string) — issue 0128.
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// Pre-fix, the call read the pointer register pair as {ptr, len} and the
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// length was garbage (bus error on print).
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#import "modules/std.sx";
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libc :: #library "c";
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err_text :: (code: i32) -> [:0]u8 #foreign libc "strerror";
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sig_text :: (sig: i32) -> ?[:0]u8 #foreign libc "strsignal";
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dlerror :: () -> ?[:0]u8 #foreign libc;
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main :: () -> i32 {
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// plain: strerror(0) = "Undefined error: 0" on macOS — assert shape,
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// not the exact text (locale/platform variance)
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t := err_text(2);
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if t.len < 5 { print("BUG: strerror too short ({})\n", t.len); return 1; }
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print("strerror(2) len ok\n");
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// optional, non-null branch
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o := sig_text(2);
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if o == null { print("BUG: strsignal null\n"); return 2; }
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if o!.len < 3 { print("BUG: strsignal too short\n"); return 3; }
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print("optional non-null ok\n");
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// optional, NULL branch: dlerror() with no pending error is NULL
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d := dlerror();
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if d != null { print("BUG: dlerror non-null\n"); return 4; }
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print("optional null ok\n");
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return 0;
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}
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