From ea1734773ba9913e32318aba963cdcb9f51128d4 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Sat, 17 Aug 2019 19:47:49 -0400
Subject: add compile error for async frames depending on themselves

---
 test/compile_errors.zig | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

(limited to 'test/compile_errors.zig')

diff --git a/test/compile_errors.zig b/test/compile_errors.zig
index 654171f553..cecb37620c 100644
--- a/test/compile_errors.zig
+++ b/test/compile_errors.zig
@@ -2,6 +2,42 @@ const tests = @import("tests.zig");
 const builtin = @import("builtin");
 
 pub fn addCases(cases: *tests.CompileErrorContext) void {
+    cases.add(
+        "indirect recursion of async functions detected",
+        \\var frame: ?anyframe = null;
+        \\
+        \\export fn a() void {
+        \\    _ = async rangeSum(10);
+        \\    while (frame) |f| resume f;
+        \\}
+        \\
+        \\fn rangeSum(x: i32) i32 {
+        \\    suspend {
+        \\        frame = @frame();
+        \\    }
+        \\    frame = null;
+        \\
+        \\    if (x == 0) return 0;
+        \\    var child = rangeSumIndirect(x - 1);
+        \\    return child + 1;
+        \\}
+        \\
+        \\fn rangeSumIndirect(x: i32) i32 {
+        \\    suspend {
+        \\        frame = @frame();
+        \\    }
+        \\    frame = null;
+        \\
+        \\    if (x == 0) return 0;
+        \\    var child = rangeSum(x - 1);
+        \\    return child + 1;
+        \\}
+    ,
+        "tmp.zig:8:1: error: '@Frame(rangeSum)' depends on itself",
+        "tmp.zig:15:33: note: when analyzing type '@Frame(rangeSumIndirect)' here",
+        "tmp.zig:26:25: note: when analyzing type '@Frame(rangeSum)' here",
+    );
+
     cases.add(
         "non-async function pointer eventually is inferred to become async",
         \\export fn a() void {
-- 
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