Commits on Apr 13, 2018

1. core: Remove panics from some Layout methods …

   `Layout` is often used at the core of allocation APIs and is as a result pretty
   sensitive to codegen in various circumstances. I was profiling `-C opt-level=z`
   with a wasm project recently and noticed that the `unwrap()` wasn't removed
   inside of `Layout`, causing the program to be much larger than it otherwise
   would be. If inlining were more aggressive LLVM would have figured out that the
   panic could be eliminated, but in general the methods here can't panic in the
   first place!
   
   As a result this commit makes the following tweaks:
   
   * Removes `unwrap()` and replaces it with `unsafe` in `Layout::new` and
     `Layout::for_value`. For posterity though a debug assertion was left behind.
   * Removes an `unwrap()` in favor of `?` in the `repeat` method. The comment
     indicating that the function call couldn't panic wasn't quite right in that if
     `alloc_size` becomes too large and if `align` is high enough it could indeed
     cause a panic.
   
   This'll hopefully mean that panics never get introduced into code in the first
   place, ensuring that `opt-level=z` is closer to `opt-level=s` in this regard.

   

   alexcrichton committed Apr 13, 2018
   Configuration menu

   • View commit details
   • Copy full SHA for 68e555b
   • Browse repository at this point

   Copy the full SHA

   68e555b View commit details

   Browse the repository at this point in the history