From 235f74a8c9caf8d3b550d8cec164cf7f9d1444f6 Mon Sep 17 00:00:00 2001
From: agra <alex@swipelab.co>
Date: Sun, 14 Jun 2026 13:33:50 +0300
Subject: [PATCH] test(ffi-linkage): xfail example for extern data global
 (Phase 1.2c)
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Add examples/1225-ffi-extern-global.sx — '__stdinp : *void extern;'
references libSystem's stdin pointer via the bare 'extern' modifier on
a typed var decl (the extern-named counterpart of the #foreign global
in examples/1205). Hand-authored snapshot expects the success output.

RED: 1225 is the sole corpus failure (636 ran, 1 failed) — parse error,
'extern' after a type annotation is not yet accepted in the var-decl
path. Phase 1.2d parses it and lowers the extern global.

xfail commit per the cadence rule.
---
 current/CHECKPOINT-EXTERN-EXPORT.md             |  3 +++
 examples/1225-ffi-extern-global.sx              | 15 +++++++++++++++
 examples/expected/1225-ffi-extern-global.exit   |  1 +
 examples/expected/1225-ffi-extern-global.stderr |  1 +
 examples/expected/1225-ffi-extern-global.stdout |  1 +
 5 files changed, 21 insertions(+)
 create mode 100644 examples/1225-ffi-extern-global.sx
 create mode 100644 examples/expected/1225-ffi-extern-global.exit
 create mode 100644 examples/expected/1225-ffi-extern-global.stderr
 create mode 100644 examples/expected/1225-ffi-extern-global.stdout

diff --git a/current/CHECKPOINT-EXTERN-EXPORT.md b/current/CHECKPOINT-EXTERN-EXPORT.md
index 99f5b5e..b0442a2 100644
--- a/current/CHECKPOINT-EXTERN-EXPORT.md
+++ b/current/CHECKPOINT-EXTERN-EXPORT.md
@@ -80,6 +80,9 @@ historical carve-out — keep `issues/*.md` provenance, gate the live tree only.
   extern_name → declare under C name, map sx→C) and extends the dedupe guard to
   extern. 1224 green (`c_abs`→`abs`); 1223 unregressed. Suite green (635/443).
   `green` commit. extern_lib parsed+stored (lib linking stays the `#library` axis).
+- (1.2c) Added `examples/1225-ffi-extern-global.sx` (`__stdinp : *void extern;`,
+  mirrors `#foreign` global 1205) + success snapshot. RED (636 ran, 1 failed — parse
+  error: var-decl `extern` not accepted). `xfail`; 1.2d greens it.
 
 ## Known issues
 - **Workflow hazard (1.2):** an editor format-on-save (or `zig fmt`) clobbered the
diff --git a/examples/1225-ffi-extern-global.sx b/examples/1225-ffi-extern-global.sx
new file mode 100644
index 0000000..7612c0c
--- /dev/null
+++ b/examples/1225-ffi-extern-global.sx
@@ -0,0 +1,15 @@
+// extern data global (FFI-linkage stream, Phase 1.2): reference a symbol
+// defined elsewhere (here libSystem's __stdinp) via the bare `extern`
+// linkage modifier on a typed var decl — the extern-named counterpart of
+// `<name> : <type> #foreign;` (see examples/1205). The optional
+// `extern [LIB] ["csym"]` tail mirrors the fn form; bare here (the sx name
+// IS the C symbol, resolved against the default-linked libSystem).
+#import "modules/std.sx";
+
+__stdinp : *void extern;
+
+main :: () -> i32 {
+    addr_bits : u64 = xx @__stdinp;
+    print("stdin extern global non-null: {}\n", addr_bits != 0);
+    0
+}
diff --git a/examples/expected/1225-ffi-extern-global.exit b/examples/expected/1225-ffi-extern-global.exit
new file mode 100644
index 0000000..573541a
--- /dev/null
+++ b/examples/expected/1225-ffi-extern-global.exit
@@ -0,0 +1 @@
+0
diff --git a/examples/expected/1225-ffi-extern-global.stderr b/examples/expected/1225-ffi-extern-global.stderr
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/examples/expected/1225-ffi-extern-global.stderr
@@ -0,0 +1 @@
+
diff --git a/examples/expected/1225-ffi-extern-global.stdout b/examples/expected/1225-ffi-extern-global.stdout
new file mode 100644
index 0000000..bd1a7bc
--- /dev/null
+++ b/examples/expected/1225-ffi-extern-global.stdout
@@ -0,0 +1 @@
+stdin extern global non-null: true