compiler/rustc_monomorphize/src/util.rs

   1 use rustc_middle::ty::{self, ClosureSizeProfileData, Instance, TyCtxt};
   2 use std::fs::OpenOptions;
   3 use std::io::prelude::*;
   4
   5 /// For a given closure, writes out the data for the profiling the impact of RFC 2229 on
   6 /// closure size into a CSV.
   7 ///
   8 /// During the same compile all closures dump the information in the same file
   9 /// "closure_profile_XXXXX.csv", which is created in the directory where the compiler is invoked.
  10 pub(crate) fn dump_closure_profile<'tcx>(tcx: TyCtxt<'tcx>, closure_instance: Instance<'tcx>) {
  11     let Ok(mut file) = OpenOptions::new()
  12         .create(true)
  13         .append(true)
  14         .open(&format!("closure_profile_{}.csv", std::process::id()))
  15     else {
  16         eprintln!("Couldn't open file for writing closure profile");
  17         return;
  18     };
  19
  20     let closure_def_id = closure_instance.def_id().expect_local();
  21     let typeck_results = tcx.typeck(closure_def_id);
  22
  23     if typeck_results.closure_size_eval.contains_key(&closure_def_id) {
  24         let param_env = ty::ParamEnv::reveal_all();
  25
  26         let ClosureSizeProfileData { before_feature_tys, after_feature_tys } =
  27             typeck_results.closure_size_eval[&closure_def_id];
  28
  29         let before_feature_tys = tcx.subst_and_normalize_erasing_regions(
  30             closure_instance.substs,
  31             param_env,
  32             before_feature_tys,
  33         );
  34         let after_feature_tys = tcx.subst_and_normalize_erasing_regions(
  35             closure_instance.substs,
  36             param_env,
  37             after_feature_tys,
  38         );
  39
  40         let new_size = tcx
  41             .layout_of(param_env.and(after_feature_tys))
  42             .map(|l| format!("{:?}", l.size.bytes()))
  43             .unwrap_or_else(|e| format!("Failed {:?}", e));
  44
  45         let old_size = tcx
  46             .layout_of(param_env.and(before_feature_tys))
  47             .map(|l| format!("{:?}", l.size.bytes()))
  48             .unwrap_or_else(|e| format!("Failed {:?}", e));
  49
  50         let closure_span = tcx.def_span(closure_def_id);
  51         let src_file = tcx.sess.source_map().span_to_filename(closure_span);
  52         let line_nos = tcx
  53             .sess
  54             .source_map()
  55             .span_to_lines(closure_span)
  56             .map(|l| format!("{:?} {:?}", l.lines.first(), l.lines.last()))
  57             .unwrap_or_else(|e| format!("{:?}", e));
  58
  59         if let Err(e) = writeln!(
  60             file,
  61             "{}, {}, {}, {:?}",
  62             old_size,
  63             new_size,
  64             src_file.prefer_local(),
  65             line_nos
  66         ) {
  67             eprintln!("Error writing to file {}", e)
  68         }
  69     }
  70 }