From 823d1e70876d79dfae9dde0496e7cf293995c44a Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Mon, 5 Dec 2022 17:20:06 -0700
Subject: [PATCH] add std.heap.wasm_allocator

---
 lib/std/heap.zig | 10 ++++++++++
 src/main.zig     |  5 +----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/lib/std/heap.zig b/lib/std/heap.zig
index ac77db7a79..ee6525659e 100644
--- a/lib/std/heap.zig
+++ b/lib/std/heap.zig
@@ -224,6 +224,16 @@ else
         .vtable = &PageAllocator.vtable,
     };
 
+/// This allocator is fast, small, and specific to WebAssembly. In the future,
+/// this will be the implementation automatically selected by
+/// `GeneralPurposeAllocator` when compiling in `ReleaseSmall` mode for wasm32
+/// and wasm64 architectures.
+/// Until then, it is available here to play with.
+pub const wasm_allocator = Allocator{
+    .ptr = undefined,
+    .vtable = &std.heap.WasmAllocator.vtable,
+};
+
 /// Verifies that the adjusted length will still map to the full length
 pub fn alignPageAllocLen(full_len: usize, len: usize) usize {
     const aligned_len = mem.alignAllocLen(full_len, len);
diff --git a/src/main.zig b/src/main.zig
index 1db5693e36..67b67fa923 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -155,10 +155,7 @@ pub fn main() anyerror!void {
     const use_gpa = (build_options.force_gpa or !builtin.link_libc) and builtin.os.tag != .wasi;
     const gpa = gpa: {
         if (builtin.os.tag == .wasi) {
-            break :gpa Allocator{
-                .ptr = undefined,
-                .vtable = &std.heap.WasmAllocator.vtable,
-            };
+            break :gpa std.heap.wasm_allocator;
         }
         if (use_gpa) {
             break :gpa general_purpose_allocator.allocator();