From 6b037bad590bd6c319af336b6d3017c33d6834ba Mon Sep 17 00:00:00 2001
From: Veikka Tuominen <git@vexu.eu>
Date: Sun, 15 Jan 2023 14:06:59 +0200
Subject: [PATCH] Sema: ignore dependency loops in typeinfo decls

This matches stage1 behavior.

Closes #14322
---
 src/Sema.zig                |  1 +
 test/behavior/type_info.zig | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/src/Sema.zig b/src/Sema.zig
index fcf25ab9bf..4e479d263a 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -16258,6 +16258,7 @@ fn typeInfoNamespaceDecls(
     for (decls) |decl_index| {
         const decl = sema.mod.declPtr(decl_index);
         if (decl.kind == .@"usingnamespace") {
+            if (decl.analysis == .in_progress) continue;
             try sema.mod.ensureDeclAnalyzed(decl_index);
             var buf: Value.ToTypeBuffer = undefined;
             const new_ns = decl.val.toType(&buf).getNamespace().?;
diff --git a/test/behavior/type_info.zig b/test/behavior/type_info.zig
index ef8c89bd23..419a2f231c 100644
--- a/test/behavior/type_info.zig
+++ b/test/behavior/type_info.zig
@@ -590,3 +590,16 @@ test "@typeInfo decls and usingnamespace" {
     try expectEqualStrings(decls[1].name, "y");
     try expectEqualStrings(decls[2].name, "z");
 }
+
+test "@typeInfo decls ignore dependency loops" {
+    const S = struct {
+        fn Def(comptime T: type) type {
+            std.debug.assert(@typeInfo(T).Struct.decls.len == 1);
+            return struct {
+                const foo = u32;
+            };
+        }
+        usingnamespace Def(@This());
+    };
+    _ = S.foo;
+}