From eff2283dab963a21e14a71585003051d3ea9056c Mon Sep 17 00:00:00 2001
From: Winter <winter@winter.cafe>
Date: Mon, 30 Jan 2023 21:34:33 -0500
Subject: [PATCH] Hide `iconv` functions on Apple devices behind a feature flag

---
 Cargo.toml                  |  1 +
 README.md                   |  2 ++
 src/unix/bsd/apple/iconv.rs | 11 +++++++++++
 src/unix/bsd/apple/mod.rs   | 26 +++++++++++++-------------
 4 files changed, 27 insertions(+), 13 deletions(-)
 create mode 100644 src/unix/bsd/apple/iconv.rs

diff --git a/Cargo.toml b/Cargo.toml
index 15c2b9bf53b8d..52c2151379cb9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,6 +28,7 @@ align = []
 rustc-dep-of-std = ['align', 'rustc-std-workspace-core']
 extra_traits = []
 const-extern-fn = []
+iconv-apple = []
 # use_std is deprecated, use `std` instead
 use_std = [ 'std' ]
 
diff --git a/README.md b/README.md
index bc5ad18f6b1b8..4f87ce57779eb 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,8 @@ libc = "0.2"
   If you use Rust >= 1.62, this feature is implicitly enabled.
   Otherwise it requires a nightly rustc.
 
+* `iconv-apple`: Enables usage of `iconv_open`, `iconv`, and `iconv_close` on Apple devices.
+
 * **deprecated**: `use_std` is deprecated, and is equivalent to `std`.
 
 ## Rust version support
diff --git a/src/unix/bsd/apple/iconv.rs b/src/unix/bsd/apple/iconv.rs
new file mode 100644
index 0000000000000..5c9e39ec212ab
--- /dev/null
+++ b/src/unix/bsd/apple/iconv.rs
@@ -0,0 +1,11 @@
+extern "C" {
+    pub fn iconv_open(tocode: *const ::c_char, fromcode: *const ::c_char) -> iconv_t;
+    pub fn iconv(
+        cd: iconv_t,
+        inbuf: *mut *mut ::c_char,
+        inbytesleft: *mut ::size_t,
+        outbuf: *mut *mut ::c_char,
+        outbytesleft: *mut ::size_t,
+    ) -> ::size_t;
+    pub fn iconv_close(cd: iconv_t) -> ::c_int;
+}
diff --git a/src/unix/bsd/apple/mod.rs b/src/unix/bsd/apple/mod.rs
index 24a6d61033dd1..1d0f81a608ac6 100644
--- a/src/unix/bsd/apple/mod.rs
+++ b/src/unix/bsd/apple/mod.rs
@@ -5908,19 +5908,19 @@ cfg_if! {
 }
 
 // These require a dependency on `libiconv`, and including this when built as
-// part of `std` means every Rust program gets it. Ideally we would have a link
-// modifier to only include these if they are used, but we do not.
-#[cfg_attr(not(feature = "rustc-dep-of-std"), link(name = "iconv"))]
-extern "C" {
-    pub fn iconv_open(tocode: *const ::c_char, fromcode: *const ::c_char) -> iconv_t;
-    pub fn iconv(
-        cd: iconv_t,
-        inbuf: *mut *mut ::c_char,
-        inbytesleft: *mut ::size_t,
-        outbuf: *mut *mut ::c_char,
-        outbytesleft: *mut ::size_t,
-    ) -> ::size_t;
-    pub fn iconv_close(cd: iconv_t) -> ::c_int;
+// part of `std` means every Rust program gets it. Additionally, when not built
+// as part of `std`, merely using `libc` on an Apple target will pull in `libiconv`.
+//
+// Therefore, due to these functions very low usage numbers on the platform, we hide it
+// behind a feature flag.
+//
+// Ideally we would have a link modifier to only include these if they are used, but we do not.
+cfg_if! {
+    if #[cfg(feature = "iconv-apple")] {
+        #[link(name = "iconv")]
+        mod iconv;
+        pub use self::iconv::*;
+    }
 }
 
 cfg_if! {