From 7d0b6956c0935807f0e5862c45da857e8e065c6b Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 15 Mar 2022 13:29:54 -0700
Subject: [PATCH] stage2: resolve type fully when resolving inferred allocs

We must resolve the type fully so that pointer children (i.e. slices)
are resolved. Additionally, we must resolve even if we can know the
value at comptime because the `alloc_inferred` ZIR always produces a
constant in the AIR.

Fixes #11181
---
 src/Sema.zig                 |  7 ++++++-
 test/behavior.zig            |  1 +
 test/behavior/bugs/11181.zig | 31 +++++++++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 test/behavior/bugs/11181.zig

diff --git a/src/Sema.zig b/src/Sema.zig
index 8fc6b19e46..8c81f96edf 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -2672,11 +2672,16 @@ fn zirResolveInferredAlloc(sema: *Sema, block: *Block, inst: Zir.Inst.Index) Com
                 // ZIR handles it later, so we can just use the ty ref here.
                 air_datas[ptr_inst].ty_pl.ty = air_datas[bitcast_inst].ty_op.ty;
 
+                // Unless the block is comptime, `alloc_inferred` always produces
+                // a runtime constant. The final inferred type needs to be
+                // fully resolved so it can be lowered in codegen.
+                try sema.resolveTypeFully(block, ty_src, final_elem_ty);
+
                 return;
             }
 
             try sema.requireRuntimeBlock(block, src);
-            try sema.resolveTypeLayout(block, ty_src, final_elem_ty);
+            try sema.resolveTypeFully(block, ty_src, final_elem_ty);
 
             // Change it to a normal alloc.
             sema.air_instructions.set(ptr_inst, .{
diff --git a/test/behavior.zig b/test/behavior.zig
index 9e0cb50558..edc9953e59 100644
--- a/test/behavior.zig
+++ b/test/behavior.zig
@@ -66,6 +66,7 @@ test {
     _ = @import("behavior/bugs/11046.zig");
     _ = @import("behavior/bugs/11139.zig");
     _ = @import("behavior/bugs/11165.zig");
+    _ = @import("behavior/bugs/11181.zig");
     _ = @import("behavior/call.zig");
     _ = @import("behavior/cast.zig");
     _ = @import("behavior/comptime_memory.zig");
diff --git a/test/behavior/bugs/11181.zig b/test/behavior/bugs/11181.zig
new file mode 100644
index 0000000000..f7baed5774
--- /dev/null
+++ b/test/behavior/bugs/11181.zig
@@ -0,0 +1,31 @@
+const builtin = @import("builtin");
+
+test "const inferred array of slices" {
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+
+    const T = struct { v: bool };
+
+    const decls = [_][]const T{
+        &[_]T{
+            .{ .v = false },
+        },
+    };
+    _ = decls;
+}
+
+test "var inferred array of slices" {
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+
+    const T = struct { v: bool };
+
+    var decls = [_][]const T{
+        &[_]T{
+            .{ .v = false },
+        },
+    };
+    _ = decls;
+}