From 9a926e5d6c100d169b936a66120b7107c016ae5b Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Wed, 25 May 2022 16:24:07 +1000
Subject: [PATCH] Fix metadata stats.
This commit:
- Counts some things that weren't being counted previously, and adds
an assertion that ensure everything is counted.
- Reorders things so the `eprintln`s order matches the code order.
- Adds percentages, and makes clear that the zero bytes count is orthogonal to
the other measurements.
Example of the new output:
```
55463779 metadata bytes, of which 18054531 bytes (32.6%) are zero
preamble: 30 bytes ( 0.0%)
dep: 0 bytes ( 0.0%)
lib feature: 17458 bytes ( 0.0%)
lang item: 337 bytes ( 0.0%)
diagnostic item: 1788 bytes ( 0.0%)
native lib: 0 bytes ( 0.0%)
foreign modules: 5113 bytes ( 0.0%)
def-path table: 720180 bytes ( 1.3%)
traits: 359 bytes ( 0.0%)
impls: 64624 bytes ( 0.1%)
incoherent_impls: 130 bytes ( 0.0%)
mir: 16137354 bytes (29.1%)
item: 23773099 bytes (42.9%)
interpret_alloc_index: 599 bytes ( 0.0%)
proc-macro-data: 0 bytes ( 0.0%)
tables: 10081135 bytes (18.2%)
debugger visualizers: 0 bytes ( 0.0%)
exported symbols: 5666 bytes ( 0.0%)
hygiene: 1539390 bytes ( 2.8%)
def-path hashes: 2752564 bytes ( 5.0%)
source_map: 363540 bytes ( 0.7%)
final: 413 bytes ( 0.0%)
```
---
compiler/rustc_metadata/src/rmeta/encoder.rs | 92 +++++++++++++++-----
1 file changed, 69 insertions(+), 23 deletions(-)
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index e66d226a441..8534188d18a 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -539,9 +539,11 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
fn encode_crate_root(&mut self) -> Lazy<CrateRoot<'tcx>> {
let tcx = self.tcx;
- let mut i = self.position();
+ let mut i = 0;
+ let preamble_bytes = self.position() - i;
// Encode the crate deps
+ i = self.position();
let crate_deps = self.encode_crate_deps();
let dylib_dependency_formats = self.encode_dylib_dependency_formats();
let dep_bytes = self.position() - i;
@@ -567,7 +569,9 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
let native_libraries = self.encode_native_libraries();
let native_lib_bytes = self.position() - i;
+ i = self.position();
let foreign_modules = self.encode_foreign_modules();
+ let foreign_modules_bytes = self.position() - i;
// Encode DefPathTable
i = self.position();
@@ -587,6 +591,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
i = self.position();
let incoherent_impls = self.encode_incoherent_impls();
let incoherent_impls_bytes = self.position() - i;
+
// Encode MIR.
i = self.position();
self.encode_mir();
@@ -599,6 +604,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
let item_bytes = self.position() - i;
// Encode the allocation index
+ i = self.position();
let interpret_alloc_index = {
let mut interpret_alloc_index = Vec::new();
let mut n = 0;
@@ -621,6 +627,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
}
self.lazy(interpret_alloc_index)
};
+ let interpret_alloc_index_bytes = self.position() - i;
// Encode the proc macro data. This affects 'tables',
// so we need to do this before we encode the tables
@@ -665,9 +672,9 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
let source_map = self.encode_source_map();
let source_map_bytes = self.position() - i;
+ i = self.position();
let attrs = tcx.hir().krate_attrs();
let has_default_lib_allocator = tcx.sess.contains_name(&attrs, sym::default_lib_allocator);
-
let root = self.lazy(CrateRoot {
name: tcx.crate_name(LOCAL_CRATE),
extra_filename: tcx.sess.opts.cg.extra_filename.clone(),
@@ -710,9 +717,34 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
expn_hashes,
def_path_hash_map,
});
+ let final_bytes = self.position() - i;
let total_bytes = self.position();
+ let computed_total_bytes = preamble_bytes
+ + dep_bytes
+ + lib_feature_bytes
+ + lang_item_bytes
+ + diagnostic_item_bytes
+ + native_lib_bytes
+ + foreign_modules_bytes
+ + def_path_table_bytes
+ + traits_bytes
+ + impls_bytes
+ + incoherent_impls_bytes
+ + mir_bytes
+ + item_bytes
+ + interpret_alloc_index_bytes
+ + proc_macro_data_bytes
+ + tables_bytes
+ + debugger_visualizers_bytes
+ + exported_symbols_bytes
+ + hygiene_bytes
+ + def_path_hash_map_bytes
+ + source_map_bytes
+ + final_bytes;
+ assert_eq!(total_bytes, computed_total_bytes);
+
if tcx.sess.meta_stats() {
let mut zero_bytes = 0;
for e in self.opaque.data.iter() {
@@ -721,27 +753,41 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
}
}
- eprintln!("metadata stats:");
- eprintln!(" dep bytes: {}", dep_bytes);
- eprintln!(" lib feature bytes: {}", lib_feature_bytes);
- eprintln!(" lang item bytes: {}", lang_item_bytes);
- eprintln!(" diagnostic item bytes: {}", diagnostic_item_bytes);
- eprintln!(" native bytes: {}", native_lib_bytes);
- eprintln!(" debugger visualizers bytes: {}", debugger_visualizers_bytes);
- eprintln!(" source_map bytes: {}", source_map_bytes);
- eprintln!(" traits bytes: {}", traits_bytes);
- eprintln!(" impls bytes: {}", impls_bytes);
- eprintln!(" incoherent_impls bytes: {}", incoherent_impls_bytes);
- eprintln!(" exp. symbols bytes: {}", exported_symbols_bytes);
- eprintln!(" def-path table bytes: {}", def_path_table_bytes);
- eprintln!(" def-path hashes bytes: {}", def_path_hash_map_bytes);
- eprintln!(" proc-macro-data-bytes: {}", proc_macro_data_bytes);
- eprintln!(" mir bytes: {}", mir_bytes);
- eprintln!(" item bytes: {}", item_bytes);
- eprintln!(" table bytes: {}", tables_bytes);
- eprintln!(" hygiene bytes: {}", hygiene_bytes);
- eprintln!(" zero bytes: {}", zero_bytes);
- eprintln!(" total bytes: {}", total_bytes);
+ let perc = |bytes| (bytes * 100) as f64 / total_bytes as f64;
+ let p = |label, bytes| {
+ eprintln!("{:>21}: {:>8} bytes ({:4.1}%)", label, bytes, perc(bytes));
+ };
+
+ eprintln!("");
+ eprintln!(
+ "{} metadata bytes, of which {} bytes ({:.1}%) are zero",
+ total_bytes,
+ zero_bytes,
+ perc(zero_bytes)
+ );
+ p("preamble", preamble_bytes);
+ p("dep", dep_bytes);
+ p("lib feature", lib_feature_bytes);
+ p("lang item", lang_item_bytes);
+ p("diagnostic item", diagnostic_item_bytes);
+ p("native lib", native_lib_bytes);
+ p("foreign modules", foreign_modules_bytes);
+ p("def-path table", def_path_table_bytes);
+ p("traits", traits_bytes);
+ p("impls", impls_bytes);
+ p("incoherent_impls", incoherent_impls_bytes);
+ p("mir", mir_bytes);
+ p("item", item_bytes);
+ p("interpret_alloc_index", interpret_alloc_index_bytes);
+ p("proc-macro-data", proc_macro_data_bytes);
+ p("tables", tables_bytes);
+ p("debugger visualizers", debugger_visualizers_bytes);
+ p("exported symbols", exported_symbols_bytes);
+ p("hygiene", hygiene_bytes);
+ p("def-path hashes", def_path_hash_map_bytes);
+ p("source_map", source_map_bytes);
+ p("final", final_bytes);
+ eprintln!("");
}
root