From 5eeeed1aa1d84145250d1b0f9561bee4d4e7cda7 Mon Sep 17 00:00:00 2001 From: jyn Date: Wed, 5 Apr 2023 08:57:54 -0400 Subject: [PATCH] Greatly decrease the size of `rustc_driver.so` when debuginfo is enabled - Only add -gz if it's supported - Don't include extra unnecessary debuginfo when only debuginfo-level=1 is set - Compress debuginfo sections to reduce the size of debuginfo on disk. before: 650 MB line tables only: 335 MB compressed only: 216 MB compressed and line tables: 186 MB no debuginfo at all: 130 MB I want to investigate why `-C line-tables-only` is still ~tripling the size of the binary, but this seems like a good improvement in the meantime. I've tested that both valgrind and perf can read the debuginfo: ``` (bash@dev-desktop-us-1.infra.rust-lang.org) ~/rust [08:31:08] ; valgrind $(rustup which rustc --toolchain rust_stage2) --version ==441671== Memcheck, a memory error detector ==441671== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==441671== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info ==441671== Command: /home/gh-jyn514/.local/lib/rustup/toolchains/rust_stage2/bin/rustc --version ==441671== rustc 1.70.0-dev ==441671== ==441671== HEAP SUMMARY: ==441671== in use at exit: 231,289 bytes in 1,874 blocks ==441671== total heap usage: 2,538 allocs, 664 frees, 486,368 bytes allocated ==441671== ==441671== LEAK SUMMARY: ==441671== definitely lost: 70,656 bytes in 1 blocks ==441671== indirectly lost: 0 bytes in 0 blocks ==441671== possibly lost: 0 bytes in 0 blocks ==441671== still reachable: 160,633 bytes in 1,873 blocks ==441671== suppressed: 0 bytes in 0 blocks ==441671== Rerun with --leak-check=full to see details of leaked memory ==441671== ==441671== For lists of detected and suppressed errors, rerun with: -s ==441671== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0) ; perf record $(rustup which rustc --toolchain rust_stage2) --version rustc 1.70.0-dev [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.005 MB perf.data (70 samples) ] ; perf report Samples: 70 of event 'cycles:u', Event count (approx.): 21356967 Overhead Command Shared Object Symbol 51.55% rustc ld-linux-aarch64.so.1 [.] _dl_lookup_symbol_x 18.70% rustc ld-linux-aarch64.so.1 [.] _dl_relocate_object 11.95% rustc ld-linux-aarch64.so.1 [.] do_lookup_x 5.55% rustc [unknown] [k] 0xffffa9ad41cfcfdc 2.68% rustc libc.so.6 [.] __GI___strlen_asimd 2.42% rustc librustc_driver-1a385c366c35e81a.so [.] llvm::StringMapImpl::LookupBucketFor 2.16% rustc librustc_driver-1a385c366c35e81a.so [.] _GLOBAL__sub_I_X86InstructionSelector.cpp 1.96% rustc libstd-990fe978dab76ef3.so [.] as core::clone::Clone>::clone 1.60% rustc librustc_driver-1a385c366c35e81a.so [.] llvm::cl::opt >::~opt 1.22% rustc ld-linux-aarch64.so.1 [.] strcmp 0.13% rustc ld-linux-aarch64.so.1 [.] stat64 0.05% rustc ld-linux-aarch64.so.1 [.] __minimal_calloc 0.02% rustc ld-linux-aarch64.so.1 [.] __GI___tunables_init 0.02% rustc ld-linux-aarch64.so.1 [.] _dl_start 0.00% rustc [unknown] [k] 0xffffa9ad41cfd844 0.00% rustc ld-linux-aarch64.so.1 [.] _start ``` --- src/bootstrap/builder.rs | 10 +++++++++- src/bootstrap/cc_detect.rs | 2 ++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs index 43c859b0063..9423f309cb1 100644 --- a/src/bootstrap/builder.rs +++ b/src/bootstrap/builder.rs @@ -1673,7 +1673,15 @@ impl<'a> Builder<'a> { self.config.rust_debuginfo_level_tools } }; - cargo.env(profile_var("DEBUG"), debuginfo_level.to_string()); + if debuginfo_level == 1 { + // Use less debuginfo than the default to save on disk space. + cargo.env(profile_var("DEBUG"), "line-tables-only"); + } else { + cargo.env(profile_var("DEBUG"), debuginfo_level.to_string()); + }; + if self.cc[&target].args().iter().any(|arg| arg == "-gz") { + rustflags.arg("-Clink-arg=-gz"); + } cargo.env( profile_var("DEBUG_ASSERTIONS"), if mode == Mode::Std { diff --git a/src/bootstrap/cc_detect.rs b/src/bootstrap/cc_detect.rs index 65c882fb801..db3b69d18c8 100644 --- a/src/bootstrap/cc_detect.rs +++ b/src/bootstrap/cc_detect.rs @@ -69,6 +69,8 @@ fn new_cc_build(build: &Build, target: TargetSelection) -> cc::Build { .opt_level(2) .warnings(false) .debug(false) + // Compress debuginfo + .flag_if_supported("-gz") .target(&target.triple) .host(&build.build.triple); match build.crt_static(target) {