From 92f87dca4987555fe8a87504dea68b37a29d62b9 Mon Sep 17 00:00:00 2001
From: Alexandre Bury <alexandre.bury@gmail.com>
Date: Fri, 13 Oct 2023 09:49:58 -0400
Subject: [PATCH] Add no_wasm_shim feature

---
 zstd-safe/zstd-sys/Cargo.toml | 5 +++--
 zstd-safe/zstd-sys/build.rs   | 7 ++++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/zstd-safe/zstd-sys/Cargo.toml b/zstd-safe/zstd-sys/Cargo.toml
index 60ea4c2d..56047453 100644
--- a/zstd-safe/zstd-sys/Cargo.toml
+++ b/zstd-safe/zstd-sys/Cargo.toml
@@ -69,12 +69,13 @@ debug = [] # Enable zstd debug logs
 experimental = [] # Expose experimental ZSTD API
 legacy = [] # Enable legacy ZSTD support (for versions < zstd-0.8)
 non-cargo = [] # Silence cargo-specific build flags
-pkg-config = []
+pkg-config = [] # Use pkg-config to build the zstd C library.
 std = [] # Deprecated: we never use types from std.
 zstdmt = [] # Enable multi-thread support (with pthread)
 thin = [] # Optimize binary by size
 no_asm = [] # Disable ASM files (only on amd64 for decompression)
-zdict_builder = []
+zdict_builder = [] # Enable dictionary building (dictionary _using_ is always supported).
+no_wasm_shim = [] # Disable wasm shims (in case your wasm toolchain includes a C stdlib).
 
 # These two are for cross-language LTO.
 # Will only work if `clang` is used to build the C library.
diff --git a/zstd-safe/zstd-sys/build.rs b/zstd-safe/zstd-sys/build.rs
index 65303b16..c7b52f51 100644
--- a/zstd-safe/zstd-sys/build.rs
+++ b/zstd-safe/zstd-sys/build.rs
@@ -133,9 +133,10 @@ fn compile_zstd() {
     // Note that Emscripten already provides its own C standard library so
     // wasm32-unknown-emscripten should not be included here.
     // See: https://github.com/gyscos/zstd-rs/pull/209
-    let need_wasm_shim = env::var("TARGET").map_or(false, |target| {
-        target == "wasm32-unknown-unknown" || target == "wasm32-wasi"
-    });
+    let need_wasm_shim = !cfg!(feature = "no_wasm_shim")
+        && env::var("TARGET").map_or(false, |target| {
+            target == "wasm32-unknown-unknown" || target == "wasm32-wasi"
+        });
 
     if need_wasm_shim {
         cargo_print(&"rerun-if-changed=wasm-shim/stdlib.h");