From a3da3eea8f3bf0c9e26a84e9c280662d95c6bda2 Mon Sep 17 00:00:00 2001
From: Ryan King <code@ryank.ing>
Date: Wed, 17 Jun 2026 22:36:19 +0200
Subject: [PATCH] wasm: add externref and funcref address spaces (#35813)
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closes https://codeberg.org/ziglang/zig/issues/31190

Reviewed-on: https://codeberg.org/ziglang/zig/pulls/35813
Reviewed-by: Alex Rønne Petersen <alex@alexrp.com>
---
 lib/std/Target.zig           | 1 +
 lib/std/lang.zig             | 4 ++++
 src/codegen/llvm.zig         | 4 ++--
 src/codegen/spirv/Module.zig | 2 ++
 4 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/std/Target.zig b/lib/std/Target.zig
index 3d4886e47d0e7d5ffa4b4ed0b53e0f12d2668a20..98eb5a8b46361335173e924a4d03727d295b0674 100644
--- a/lib/std/Target.zig
+++ b/lib/std/Target.zig
@@ -2347,6 +2347,7 @@ pub fn supportsAddressSpace(
             (is_spirv and (context == null or context == .constant or context == .pointer)),
         .param => is_nvptx,
         .input, .output, .uniform, .push_constant, .storage_buffer, .physical_storage_buffer => is_spirv,
+        .externref, .funcref => target.cpu.has(.wasm, .reference_types),
     };
 }
 
diff --git a/lib/std/lang.zig b/lib/std/lang.zig
index 7f04a24804bc5cafb02fc6d83c8fd7d3fedaeac8..c108d7050d003465ec080d76335ac25e3ded3446 100644
--- a/lib/std/lang.zig
+++ b/lib/std/lang.zig
@@ -567,6 +567,10 @@ pub const AddressSpace = enum(u5) {
 
     /// This address space only addresses the "lookup" ram
     lut,
+
+    // Web Assembly
+    externref,
+    funcref,
 };
 
 /// This data structure is used by the Zig language code generation and
diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index 0b5f8490ce10f90397847f8fd3c520c3632c285b..f687382dada59d488106487c1e32b0540d0086f3 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -4674,8 +4674,8 @@ fn llvmAddrSpaceInfo(target: *const std.Target) []const AddrSpaceInfo {
         .wasm32, .wasm64 => &.{
             .{ .zig = .generic, .llvm = Builder.AddrSpace.wasm.default, .force_in_data_layout = true },
             .{ .zig = null, .llvm = Builder.AddrSpace.wasm.variable, .non_integral = true },
-            .{ .zig = null, .llvm = Builder.AddrSpace.wasm.externref, .non_integral = true, .size = 8, .abi = 8 },
-            .{ .zig = null, .llvm = Builder.AddrSpace.wasm.funcref, .non_integral = true, .size = 8, .abi = 8 },
+            .{ .zig = .externref, .llvm = Builder.AddrSpace.wasm.externref, .non_integral = true, .size = 8, .abi = 8 },
+            .{ .zig = .funcref, .llvm = Builder.AddrSpace.wasm.funcref, .non_integral = true, .size = 8, .abi = 8 },
         },
         .m68k => &.{
             .{ .zig = .generic, .llvm = .default, .abi = 16, .pref = 32 },
diff --git a/src/codegen/spirv/Module.zig b/src/codegen/spirv/Module.zig
index 52e8588cafac531df34583644a9b0f74ba391a58..a4e30f2ec9d75321c419e7ed0fc391955a67dced 100644
--- a/src/codegen/spirv/Module.zig
+++ b/src/codegen/spirv/Module.zig
@@ -1059,6 +1059,8 @@ pub fn storageClass(module: *Module, as: std.lang.AddressSpace) spec.StorageClas
         .cog,
         .lut,
         .hub,
+        .externref,
+        .funcref,
         => unreachable,
     };
 }
-- 
2.54.0