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 crate fn dump_closure_profile<'tcx>(tcx: TyCtxt<'tcx>, closure_instance: Instance<'tcx>) {
  11     let mut file = if let Ok(file) = OpenOptions::new()
  12         .create(true)
  13         .append(true)
  14         .open(&format!("closure_profile_{}.csv", std::process::id()))
  15     {
  16         file
  17     } else {
  18         eprintln!("Cound't open file for writing closure profile");
  19         return;
  20     };
  21
  22     let closure_def_id = closure_instance.def_id();
  23     let typeck_results = tcx.typeck(closure_def_id.expect_local());
  24
  25     if typeck_results.closure_size_eval.contains_key(&closure_def_id) {
  26         let param_env = ty::ParamEnv::reveal_all();
  27
  28         let ClosureSizeProfileData { before_feature_tys, after_feature_tys } =
  29             typeck_results.closure_size_eval[&closure_def_id];
  30
  31         let before_feature_tys = tcx.subst_and_normalize_erasing_regions(
  32             closure_instance.substs,
  33             param_env,
  34             before_feature_tys,
  35         );
  36         let after_feature_tys = tcx.subst_and_normalize_erasing_regions(
  37             closure_instance.substs,
  38             param_env,
  39             after_feature_tys,
  40         );
  41
  42         let new_size = tcx
  43             .layout_of(param_env.and(after_feature_tys))
  44             .map(|l| format!("{:?}", l.size.bytes()))
  45             .unwrap_or_else(|e| format!("Failed {:?}", e));
  46
  47         let old_size = tcx
  48             .layout_of(param_env.and(before_feature_tys))
  49             .map(|l| format!("{:?}", l.size.bytes()))
  50             .unwrap_or_else(|e| format!("Failed {:?}", e));
  51
  52         let closure_span = tcx.def_span(closure_def_id);
  53         let src_file = tcx.sess.source_map().span_to_filename(closure_span);
  54         let line_nos = tcx
  55             .sess
  56             .source_map()
  57             .span_to_lines(closure_span)
  58             .map(|l| format!("{:?} {:?}", l.lines.first(), l.lines.last()))
  59             .unwrap_or_else(|e| format!("{:?}", e));
  60
  61         if let Err(e) = writeln!(
  62             file,
  63             "{}, {}, {}, {:?}",
  64             old_size,
  65             new_size,
  66             src_file.prefer_local(),
  67             line_nos
  68         ) {
  69             eprintln!("Error writing to file {}", e)
  70         }
  71     }
  72 }