- 
                Notifications
    You must be signed in to change notification settings 
- Fork 13.9k
          mir: add used_generic_parameters_needs_subst
          #74717
        
          New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
          
     Merged
      
      
            bors
  merged 1 commit into
  rust-lang:master
from
davidtwco:issue-74636-polymorphized-closures-inherited-params
  
      
      
   
  Aug 1, 2020 
      
    
                
     Merged
            
            
  
    mir: add used_generic_parameters_needs_subst
  
  #74717
              
                    bors
  merged 1 commit into
  rust-lang:master
from
davidtwco:issue-74636-polymorphized-closures-inherited-params
  
      
      
   
  Aug 1, 2020 
              
            Conversation
  
    
      This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
      Learn more about bidirectional Unicode characters
    
  
  
    
    | r? @oli-obk I got a crash course in polymorphization magic in https://rust-lang.zulipchat.com/#narrow/stream/216091-t-compiler.2Fwg-polymorphization/topic/tokio.20regression.20%28.2374614%29/near/205594913 | 
This commit adds a `ensure_monomorphic_enough` utility function which checks whether a type needs substitution, but only for parameters that the `unused_generic_params` query considers used. `ensure_monomorphic_enough` is then used throughout interpret where `needs_subst` checks previously existed (in particular, for some pointer casts and for reflection intrinsics more precise). Signed-off-by: David Wood <[email protected]>
4d1d988    to
    59e621c      
    Compare
  
    | cc @rust-lang/wg-const-eval @bors r+ | 
| 📌 Commit 59e621c has been approved by  | 
              
                    lcnr
  
              
              reviewed
              
                  
                    Jul 31, 2020 
                  
              
              
            
            
| ☀️ Test successful - checks-actions, checks-azure | 
    
  bors 
      added a commit
        to rust-lang-ci/rust
      that referenced
      this pull request
    
      Aug 5, 2020 
    
    
      
  
    
      
    
  
…optimisations, r=lcnr polymorphization: various improvements This PR includes a handful of polymorphisation-related changes: - @Mark-Simulacrum's suggestions [from this comment](rust-lang#74633 (comment)): - Use a `FiniteBitSet<u32>` over a `FiniteBitSet<u64>` as most functions won't have 64 generic parameters. - Don't encode polymorphisation results in metadata when every parameter is used (in this case, just invoking polymorphisation will probably be quicker). - @lcnr's suggestion [from this comment](rust-lang#74717 (comment)). - Add an debug assertion in `ensure_monomorphic_enough` to make sure that polymorphisation did what we expect. r? @lcnr
  
    Sign up for free
    to join this conversation on GitHub.
    Already have an account?
    Sign in to comment
  
      Labels
      
    merged-by-bors
  This PR was explicitly merged by bors. 
  
    S-waiting-on-bors
  Status: Waiting on bors to run and complete tests. Bors will change the label on completion. 
  Add this suggestion to a batch that can be applied as a single commit.
  This suggestion is invalid because no changes were made to the code.
  Suggestions cannot be applied while the pull request is closed.
  Suggestions cannot be applied while viewing a subset of changes.
  Only one suggestion per line can be applied in a batch.
  Add this suggestion to a batch that can be applied as a single commit.
  Applying suggestions on deleted lines is not supported.
  You must change the existing code in this line in order to create a valid suggestion.
  Outdated suggestions cannot be applied.
  This suggestion has been applied or marked resolved.
  Suggestions cannot be applied from pending reviews.
  Suggestions cannot be applied on multi-line comments.
  Suggestions cannot be applied while the pull request is queued to merge.
  Suggestion cannot be applied right now. Please check back later.
  
    
  
    
Fixes #74636.
This PR adds a
used_generic_parameters_needs_substhelper function which checks whether a type needs substitution, but only for parameters that theunused_generic_paramsquery considers used. This is used in the MIR interpreter to make the check for some pointer casts and for reflection intrinsics more precise.I've opened this as a draft PR because this might not be the approach we want to fix this issue and we have to decide what to do about the reflection case.
r? @eddyb
cc @lcnr @wesleywiser