From ac0bb1eec55d8bda90cbc3114e91d3b0e9f12c8b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@jakstys.lt>
Date: Fri, 20 Feb 2026 07:22:20 +0000
Subject: [PATCH] verbose_air: enable emit_bin so exported functions produce
 AIR
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With emit_bin=false, the compiler never queued functions for analysis,
making the verbose_air_callback a no-op — all corpus files produced 0
AIR functions on both C and Zig sides, so Stage 3 comparison was
vacuous.

Set emit_bin=true so that `export fn` and `@export` trigger function
analysis. Disable 5 compiler_rt corpus files that now expose the
Zig-vs-C mismatch (they use @export but C sema doesn't port zirFunc
yet). Add 3 skipped export-fn test tiers in sema_test.zig as targets
for incremental zirFunc porting.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src/verbose_air.zig    |  2 +-
 stage0/sema_test.zig   | 18 ++++++++++++++++++
 stage0/stages_test.zig | 10 +++++-----
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/src/verbose_air.zig b/src/verbose_air.zig
index fd92f434fb..461064f0c4 100644
--- a/src/verbose_air.zig
+++ b/src/verbose_air.zig
@@ -168,7 +168,7 @@ fn zigCompileAirImpl(
         .output_mode = .Obj,
         .resolved_target = resolved_target,
         .have_zcu = true,
-        .emit_bin = false,
+        .emit_bin = true,
         .is_test = false,
     });
 
diff --git a/stage0/sema_test.zig b/stage0/sema_test.zig
index 90c9dd7677..2ddede5d9b 100644
--- a/stage0/sema_test.zig
+++ b/stage0/sema_test.zig
@@ -370,3 +370,21 @@ test "sema: Air raw C vs Zig comparison (empty)" {
 test "sema: Air raw C vs Zig comparison (const)" {
     try semaAirRawCheck("const x = 0;");
 }
+
+// Tier 1-3: export fn tests — initially skipped until C sema ports zirFunc.
+// Remove `return error.SkipZigTest;` as each tier is ported.
+
+test "sema air: empty void function" {
+    if (true) return error.SkipZigTest;
+    try semaAirRawCheck("export fn f() void {}");
+}
+
+test "sema air: return integer" {
+    if (true) return error.SkipZigTest;
+    try semaAirRawCheck("export fn f() u32 { return 42; }");
+}
+
+test "sema air: identity function" {
+    if (true) return error.SkipZigTest;
+    try semaAirRawCheck("export fn f(x: u32) u32 { return x; }");
+}
diff --git a/stage0/stages_test.zig b/stage0/stages_test.zig
index 2b6fd608b2..a92a0bc45e 100644
--- a/stage0/stages_test.zig
+++ b/stage0/stages_test.zig
@@ -97,11 +97,11 @@ const corpus_files = .{
     "../lib/std/crypto/codecs.zig", // 165
     "../lib/std/os/uefi/tables/table_header.zig", // 214
     "../lib/std/zig/llvm.zig", // 247
-    "../lib/compiler_rt/neghf2.zig", // 265
-    "../lib/compiler_rt/negxf2.zig", // 265
-    "../lib/compiler_rt/absvdi2.zig", // 311
-    "../lib/compiler_rt/absvsi2.zig", // 311
-    "../lib/compiler_rt/absvti2.zig", // 314
+    //"../lib/compiler_rt/neghf2.zig", // 265 -- disabled: @export produces Zig AIR, C sema not yet ported
+    //"../lib/compiler_rt/negxf2.zig", // 265 -- disabled: @export produces Zig AIR, C sema not yet ported
+    //"../lib/compiler_rt/absvdi2.zig", // 311 -- disabled: @export produces Zig AIR, C sema not yet ported
+    //"../lib/compiler_rt/absvsi2.zig", // 311 -- disabled: @export produces Zig AIR, C sema not yet ported
+    //"../lib/compiler_rt/absvti2.zig", // 314 -- disabled: @export produces Zig AIR, C sema not yet ported
     //"../lib/compiler_rt/addhf3.zig", // 319
     //"../lib/compiler_rt/addxf3.zig", // 323
     //"../lib/compiler_rt/mulhf3.zig", // 323