Commits on Apr 4, 2016

1. mk: Hardcode the bootstrap key for each release …

   Starting with the 1.10.0 release we would like to bootstrap all compilers from
   the previous stable release. For example the 1.10.0 compiler should bootstrap
   from the literal 1.9.0 release artifacts. To do this, however, we need a way to
   enable unstable features temporarily in a stable compiler (as the released
   compiler is stable), but it turns out we already have a way to do that!
   
   At compile time the configure script selects a `CFG_BOOTSTRAP_KEY` variable
   value and then exports it into the makefiles. If the `RUSTC_BOOTSTRAP_KEY`
   environment variable is set to this value, then the compiler is allowed to
   "cheat" and use unstable features.
   
   This method of choosing the bootstrap key, however, is problematic for the
   intention of bootstrapping from the previous release. Each time a 1.9.0 compiler
   is created, a new bootstrap key will be selected. That means that the 1.10.0
   compiler will only compile from *our* literal release artifacts. Instead
   distributions would like to bootstrap from their own compilers, so instead we
   simply hardcode the bootstrap key for each release.
   
   This patch uses the same `CFG_FILENAME_EXTRA` value (a hash of the release
   string) as the bootstrap key. Consequently all 1.9.0 compilers, no matter where
   they are compiled, will have the same bootstrap key. Additionally we won't need
   to keep updating this as it'll be based on the release number anyway.
   
   Once the 1.9.0 beta has been created, we can update the 1.10.0 nightly sources
   (the `master` branch at that time) to bootstrap from that release using this
   hard-coded bootstrap key. We will likely just hardcode into the makefiles what
   the previous bootstrap key was and we'll change that whenever the stage0
   compiler is updated.

   

   alexcrichton committed Apr 4, 2016
   Configuration menu

   • View commit details
   • Copy full SHA for c822546
   • Browse repository at this point

   Copy the full SHA

   c822546 View commit details

   Browse the repository at this point in the history