From 563b1a35ed1f1151505d4fe5f723827d1b3fd4bc Mon Sep 17 00:00:00 2001 From: =?utf8?q?Alex=20Benn=C3=A9e?= Date: Thu, 6 Mar 2025 16:16:31 +0000 Subject: [PATCH] meson.build: default to -gsplit-dwarf for debug info MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This option is supported by both gcc (since 4.7) and clang (since 7.0). Not only does this make the linkers job easier by reducing the amount of ELF it needs to parse it also reduces the total build size quite considerably. In my case a default build went from 5.8G to 3.9G (vs 1.9G for --disable-debug-info). The --disable-split-debug option allows distros to keep all the info together for ease of packaging. Signed-off-by: Alex Bennée Reviewed-by: Daniel P. Berrangé Link: https://lore.kernel.org/r/20250306161631.2477685-1-alex.bennee@linaro.org Signed-off-by: Paolo Bonzini --- meson.build | 6 ++++++ meson_options.txt | 2 ++ scripts/meson-buildoptions.sh | 2 ++ 3 files changed, 10 insertions(+) diff --git a/meson.build b/meson.build index 6da4eb317c2..4899d896de0 100644 --- a/meson.build +++ b/meson.build @@ -601,6 +601,10 @@ if get_option('tsan') qemu_ldflags = ['-fsanitize=thread'] + qemu_ldflags endif +if get_option('debug') and get_option('split_debug') + qemu_cflags += '-gsplit-dwarf' +endif + # Detect support for PT_GNU_RELRO + DT_BIND_NOW. # The combination is known as "full relro", because .got.plt is read-only too. qemu_ldflags += cc.get_supported_link_arguments('-Wl,-z,relro', '-Wl,-z,now') @@ -4583,6 +4587,8 @@ if have_rust summary_info += {'bindgen': bindgen.full_path()} summary_info += {'bindgen version': bindgen.version()} endif +# option_cflags is purely for the summary display, meson will pass +# -g/-O options directly option_cflags = (get_option('debug') ? ['-g'] : []) if get_option('optimization') != 'plain' option_cflags += ['-O' + get_option('optimization')] diff --git a/meson_options.txt b/meson_options.txt index 59d973bca00..3432123fee2 100644 --- a/meson_options.txt +++ b/meson_options.txt @@ -362,6 +362,8 @@ option('debug_mutex', type: 'boolean', value: false, description: 'mutex debugging support') option('debug_stack_usage', type: 'boolean', value: false, description: 'measure coroutine stack usage') +option('split_debug', type: 'boolean', value: true, + description: 'split debug info from object files') option('qom_cast_debug', type: 'boolean', value: true, description: 'cast debugging support') option('slirp_smbd', type : 'feature', value : 'auto', diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh index 3e8e00852b2..aca6e688302 100644 --- a/scripts/meson-buildoptions.sh +++ b/scripts/meson-buildoptions.sh @@ -504,6 +504,8 @@ _meson_option_parse() { --disable-strict-rust-lints) printf "%s" -Dstrict_rust_lints=false ;; --enable-strip) printf "%s" -Dstrip=true ;; --disable-strip) printf "%s" -Dstrip=false ;; + --enable-split-debug) printf "%s" -Dsplit_debug=true ;; + --disable-split-debug) printf "%s" -Dsplit_debug=false ;; --sysconfdir=*) quote_sh "-Dsysconfdir=$2" ;; --enable-tcg) printf "%s" -Dtcg=enabled ;; --disable-tcg) printf "%s" -Dtcg=disabled ;; -- 2.47.2