Remove support for emscripten targets on rustc older than 1.40

serde/build.rs

@@ -27,13 +27,6 @@ fn main() {
         println!("cargo:rustc-cfg=no_relaxed_trait_bounds");
     }
 
-    // Disabled on Emscripten targets before Rust 1.40 since
-    // Emscripten did not support 128-bit integers until Rust 1.40
-    // (https://github.com/rust-lang/rust/pull/65251)
-    if emscripten && minor < 40 {
-        println!("cargo:rustc-cfg=no_integer128");
-    }
-
     // Current minimum supported version of serde_derive crate is Rust 1.56.
     if minor < 56 {
         println!("cargo:rustc-cfg=no_serde_derive");

serde/src/de/mod.rs

@@ -118,7 +118,6 @@ use crate::lib::*;
 
 pub mod value;
 
-#[cfg(not(no_integer128))]
 mod format;
 mod ignored_any;
 mod impls;

serde/src/integer128.rs

@@ -1,82 +1,9 @@
-/// Conditional compilation depending on whether Serde is built with support for
-/// 128-bit integers.
-///
-/// Data formats that wish to support Rust compiler versions older than 1.26
-/// (or targets that lack 128-bit integers) may place the i128 / u128 methods
-/// of their Serializer and Deserializer behind this macro.
-///
-/// Data formats that require a minimum Rust compiler version of at least 1.26,
-/// or do not target platforms that lack 128-bit integers, do not need to
-/// bother with this macro and may assume support for 128-bit integers.
-///
-/// ```edition2021
-/// # use serde::__private::doc::Error;
-/// #
-/// # struct MySerializer;
-/// #
-/// use serde::{serde_if_integer128, Serializer};
-///
-/// impl Serializer for MySerializer {
-///     type Ok = ();
-///     type Error = Error;
-///
-///     fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> {
-///         /* ... */
-/// #         unimplemented!()
-///     }
-///
-///     /* ... */
-///
-///     serde_if_integer128! {
-///         fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> {
-///             /* ... */
-/// #             unimplemented!()
-///         }
-///
-///         fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> {
-///             /* ... */
-/// #             unimplemented!()
-///         }
-///     }
-/// #
-/// #     serde::__serialize_unimplemented! {
-/// #         bool i8 i16 i32 u8 u16 u32 u64 f32 f64 char str bytes none some
-/// #         unit unit_struct unit_variant newtype_struct newtype_variant seq
-/// #         tuple tuple_struct tuple_variant map struct struct_variant
-/// #     }
-/// }
-/// ```
-///
-/// When Serde is built with support for 128-bit integers, this macro expands
-/// transparently into just the input tokens.
-///
-/// ```edition2021
-/// macro_rules! serde_if_integer128 {
-///     ($($tt:tt)*) => {
-///         $($tt)*
-///     };
-/// }
-/// ```
-///
-/// When built without support for 128-bit integers, this macro expands to
-/// nothing.
-///
-/// ```edition2021
-/// macro_rules! serde_if_integer128 {
-///     ($($tt:tt)*) => {};
-/// }
-/// ```
-#[cfg(not(no_integer128))]
+// No longer used. Old versions of serde used this macro for supporting targets
+// that did not yet have 128-bit integer support.
 #[macro_export]
+#[doc(hidden)]
 macro_rules! serde_if_integer128 {
     ($($tt:tt)*) => {
         $($tt)*
     };
 }
-
-#[cfg(no_integer128)]
-#[macro_export]
-#[doc(hidden)]
-macro_rules! serde_if_integer128 {
-    ($($tt:tt)*) => {};
-}