Make bytecode no_std compatible

Author: coolreader18

bytecode/Cargo.toml

@@ -7,13 +7,16 @@ edition = "2018"
 repository = "https://github.com/RustPython/RustPython"
 license = "MIT"
 
+[features]
+std = ["bstr/std", "itertools/use_std", "lz4_flex/std"]
+default = ["std"]
 
 [dependencies]
 bincode =  "1.1"
 bitflags = "1.1"
-lz4_flex = "0.7"
-num-bigint = { version = "0.3", features = ["serde"] }
-num-complex = { version = "0.3", features = ["serde"] }
+lz4_flex = { version = "0.7", default-features = false, features = ["safe-decode", "safe-encode"] }
+num-bigint = { version = "0.3", default-features = false, features = ["serde"] }
+num-complex = { version = "0.3", default-features = false, features = ["serde"] }
 serde = { version = "1.0", features = ["derive"] }
-itertools = "0.9"
-bstr = "0.2"
+itertools = { version = "0.9", default-features = false }
+bstr = { version = "0.2", default-features = false }

bytecode/src/lib.rs

@@ -3,15 +3,19 @@
 
 #![doc(html_logo_url = "https://raw.githubusercontent.com/RustPython/RustPython/master/logo.png")]
 #![doc(html_root_url = "https://docs.rs/rustpython-bytecode/")]
+#![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
+use alloc::collections::BTreeSet;
+use alloc::{borrow::ToOwned, boxed::Box, string::String, vec::Vec};
 use bitflags::bitflags;
 use bstr::ByteSlice;
+use core::fmt;
 use itertools::Itertools;
 use num_bigint::BigInt;
 use num_complex::Complex64;
 use serde::{Deserialize, Serialize};
-use std::collections::BTreeSet;
-use std::fmt;
 
 /// Sourcecode location.
 #[derive(Clone, Copy, Debug, Default, PartialEq, Serialize, Deserialize)]
@@ -722,6 +726,7 @@ impl fmt::Display for CodeDeserializeError {
         }
     }
 }
+#[cfg(feature = "std")]
 impl std::error::Error for CodeDeserializeError {}
 
 impl CodeObject<ConstantData> {