drop support of older nightlies

Minor version has been bumped to v0.4.0 so we can stop supporting them

This also drop the chrono dependency, which some people have been running into problems with.

closes #60

1 files changed, 0 insertions, 19 deletions

diff --git a/cortex-m-rt/build.rs b/cortex-m-rt/build.rs
index c1028c4..1d0160c 100644
--- a/cortex-m-rt/build.rs
+++ b/cortex-m-rt/build.rs
@@ -1,28 +1,9 @@
-extern crate chrono;
-extern crate rustc_version;
-
 use std::env;
 use std::fs::File;
 use std::io::Write;
 use std::path::PathBuf;
 
-use chrono::NaiveDate;
-
 fn main() {
-    let meta = rustc_version::version_meta().unwrap();
-    let commit_date = meta.commit_date.unwrap().parse::<NaiveDate>().unwrap();
-    if meta.channel == rustc_version::Channel::Dev
-        || commit_date > NaiveDate::from_ymd(2017, 12, 26)
-    {
-        println!("cargo:rustc-cfg=has_termination_lang")
-    }
-
-    // newest nightlies don't need 'extern crate compiler_builtins'
-    if commit_date < NaiveDate::from_ymd(2018, 04, 07)
-    {
-        println!("cargo:rustc-cfg=needs_cb")
-    }
-
     let target = env::var("TARGET").unwrap();
 
     has_fpu(&target);