From 414b180d42315dc77c02170f1eee8db58c9fe052 Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Fri, 24 May 2024 17:00:22 +0900 Subject: [PATCH] meson: Pass objects and dependencies to declare_dependency() We used to request declare_dependency() to link_whole static libraries. If a static library is a thin archive, GNU ld keeps all object files referenced by the archive open, and sometimes exceeds the open file limit. Another problem with link_whole is that suboptimal handling of nested dependencies. link_whole by itself does not propagate dependencies. In particular, gnutls, a dependency of crypto, is not propagated to its users, and we currently workaround the issue by declaring gnutls as a dependency for each crypto user. On the other hand, if you write something like libfoo = static_library('foo', 'foo.c', dependencies: gnutls) foo = declare_dependency(link_whole: libfoo) libbar = static_library('bar', 'bar.c', dependencies: foo) bar = declare_dependency(link_whole: libbar, dependencies: foo) executable('prog', sources: files('prog.c'), dependencies: [foo, bar]) hoping to propagate the gnutls dependency into bar.c, you'll see a linking failure for "prog", because the foo.c.o object file is included in libbar.a and therefore it is linked twice into "prog": once from libfoo.a and once from libbar.a. Here Meson does not see the duplication, it just asks the linker to link all of libfoo.a and libbar.a into "prog". Instead of using link_whole, extract objects included in static libraries and pass them to declare_dependency(); and then the dependencies can be added as well so that they are propagated, because object files on the linker command line are always deduplicated. This requires Meson 1.1.0 or later. Signed-off-by: Akihiko Odaki Message-ID: <20240524-objects-v1-1-07cbbe96166b@daynix.com> Signed-off-by: Paolo Bonzini --- docs/devel/build-system.rst | 3 ++- gdbstub/meson.build | 4 ++-- meson.build | 44 +++++++++++++++++++--------------- pythondeps.toml | 2 +- tcg/meson.build | 6 +++-- tests/qtest/libqos/meson.build | 2 +- 6 files changed, 35 insertions(+), 26 deletions(-) diff --git a/docs/devel/build-system.rst b/docs/devel/build-system.rst index f4fd76117d..39a1934c63 100644 --- a/docs/devel/build-system.rst +++ b/docs/devel/build-system.rst @@ -238,7 +238,8 @@ Subsystem sourcesets: name_suffix: 'fa', build_by_default: false) - chardev = declare_dependency(link_whole: libchardev) + chardev = declare_dependency(objects: libchardev.extract_all_objects(recursive: false), + dependencies: chardev_ss.dependencies()) As of Meson 0.55.1, the special ``.fa`` suffix should be used for everything that is used with ``link_whole``, to ensure that the link flags are placed diff --git a/gdbstub/meson.build b/gdbstub/meson.build index da5721d845..c56b54eae7 100644 --- a/gdbstub/meson.build +++ b/gdbstub/meson.build @@ -28,9 +28,9 @@ libgdb_system = static_library('gdb_system', name_suffix: 'fa', build_by_default: false) -gdb_user = declare_dependency(link_whole: libgdb_user) +gdb_user = declare_dependency(objects: libgdb_user.extract_all_objects(recursive: false)) user_ss.add(gdb_user) -gdb_system = declare_dependency(link_whole: libgdb_system) +gdb_system = declare_dependency(objects: libgdb_system.extract_all_objects(recursive: false)) system_ss.add(gdb_system) common_ss.add(files('syscalls.c')) diff --git a/meson.build b/meson.build index df9a64302f..0c314ae570 100644 --- a/meson.build +++ b/meson.build @@ -1,4 +1,4 @@ -project('qemu', ['c'], meson_version: '>=0.63.0', +project('qemu', ['c'], meson_version: '>=1.1.0', default_options: ['warning_level=1', 'c_std=gnu11', 'cpp_std=gnu++11', 'b_colorout=auto', 'b_staticpic=false', 'stdsplit=false', 'optimization=2', 'b_pie=true'], version: files('VERSION')) @@ -3461,7 +3461,7 @@ endif if enable_modules libmodulecommon = static_library('module-common', files('module-common.c') + genh, pic: true, c_args: '-DBUILD_DSO') - modulecommon = declare_dependency(link_whole: libmodulecommon, compile_args: '-DBUILD_DSO') + modulecommon = declare_dependency(objects: libmodulecommon.extract_all_objects(recursive: false), compile_args: '-DBUILD_DSO') endif qom_ss = qom_ss.apply({}) @@ -3469,14 +3469,15 @@ libqom = static_library('qom', qom_ss.sources() + genh, dependencies: [qom_ss.dependencies()], name_suffix: 'fa', build_by_default: false) -qom = declare_dependency(link_whole: libqom) +qom = declare_dependency(objects: libqom.extract_all_objects(recursive: false), + dependencies: qom_ss.dependencies()) event_loop_base = files('event-loop-base.c') event_loop_base = static_library('event-loop-base', sources: event_loop_base + genh, name_suffix: 'fa', build_by_default: false) -event_loop_base = declare_dependency(link_whole: event_loop_base, +event_loop_base = declare_dependency(objects: event_loop_base.extract_all_objects(recursive: false), dependencies: [qom]) stub_ss = stub_ss.apply({}) @@ -3621,7 +3622,8 @@ foreach d, list : modules endif emulator_modules += shared_module(sl.name(), name_prefix: '', - link_whole: sl, + objects: sl.extract_all_objects(recursive: false), + dependencies: module_ss.dependencies(), install: true, install_dir: qemu_moddir) if module_ss.sources() != [] @@ -3669,7 +3671,8 @@ foreach d, list : target_modules system_mods += sl emulator_modules += shared_module(sl.name(), name_prefix: '', - link_whole: sl, + objects: sl.extract_all_objects(recursive: false), + dependencies: target_module_ss.dependencies(), install: true, install_dir: qemu_moddir) # FIXME: Should use sl.extract_all_objects(recursive: true) too. @@ -3728,8 +3731,8 @@ libauthz = static_library('authz', authz_ss.sources() + genh, name_suffix: 'fa', build_by_default: false) -authz = declare_dependency(link_whole: libauthz, - dependencies: qom) +authz = declare_dependency(objects: libauthz.extract_all_objects(recursive: false), + dependencies: [authz_ss.dependencies(), qom]) crypto_ss = crypto_ss.apply({}) libcrypto = static_library('crypto', crypto_ss.sources() + genh, @@ -3737,8 +3740,8 @@ libcrypto = static_library('crypto', crypto_ss.sources() + genh, name_suffix: 'fa', build_by_default: false) -crypto = declare_dependency(link_whole: libcrypto, - dependencies: [authz, qom]) +crypto = declare_dependency(objects: libcrypto.extract_all_objects(recursive: false), + dependencies: [crypto_ss.dependencies(), authz, qom]) io_ss = io_ss.apply({}) libio = static_library('io', io_ss.sources() + genh, @@ -3747,12 +3750,13 @@ libio = static_library('io', io_ss.sources() + genh, name_suffix: 'fa', build_by_default: false) -io = declare_dependency(link_whole: libio, dependencies: [crypto, qom]) +io = declare_dependency(objects: libio.extract_all_objects(recursive: false), + dependencies: [io_ss.dependencies(), crypto, qom]) libmigration = static_library('migration', sources: migration_files + genh, name_suffix: 'fa', build_by_default: false) -migration = declare_dependency(link_with: libmigration, +migration = declare_dependency(objects: libmigration.extract_all_objects(recursive: false), dependencies: [qom, io]) system_ss.add(migration) @@ -3762,8 +3766,8 @@ libblock = static_library('block', block_ss.sources() + genh, name_suffix: 'fa', build_by_default: false) -block = declare_dependency(link_whole: [libblock], - dependencies: [crypto, io]) +block = declare_dependency(objects: libblock.extract_all_objects(recursive: false), + dependencies: [block_ss.dependencies(), crypto, io]) blockdev_ss = blockdev_ss.apply({}) libblockdev = static_library('blockdev', blockdev_ss.sources() + genh, @@ -3771,8 +3775,8 @@ libblockdev = static_library('blockdev', blockdev_ss.sources() + genh, name_suffix: 'fa', build_by_default: false) -blockdev = declare_dependency(link_whole: [libblockdev], - dependencies: [block, event_loop_base]) +blockdev = declare_dependency(objects: libblockdev.extract_all_objects(recursive: false), + dependencies: [blockdev_ss.dependencies(), block, event_loop_base]) qmp_ss = qmp_ss.apply({}) libqmp = static_library('qmp', qmp_ss.sources() + genh, @@ -3780,20 +3784,22 @@ libqmp = static_library('qmp', qmp_ss.sources() + genh, name_suffix: 'fa', build_by_default: false) -qmp = declare_dependency(link_whole: [libqmp]) +qmp = declare_dependency(objects: libqmp.extract_all_objects(recursive: false), + dependencies: qmp_ss.dependencies()) libchardev = static_library('chardev', chardev_ss.sources() + genh, name_suffix: 'fa', dependencies: chardev_ss.dependencies(), build_by_default: false) -chardev = declare_dependency(link_whole: libchardev) +chardev = declare_dependency(objects: libchardev.extract_all_objects(recursive: false), + dependencies: chardev_ss.dependencies()) hwcore_ss = hwcore_ss.apply({}) libhwcore = static_library('hwcore', sources: hwcore_ss.sources() + genh, name_suffix: 'fa', build_by_default: false) -hwcore = declare_dependency(link_whole: libhwcore) +hwcore = declare_dependency(objects: libhwcore.extract_all_objects(recursive: false)) common_ss.add(hwcore) ########### diff --git a/pythondeps.toml b/pythondeps.toml index 9c16602d30..6aba0c9daa 100644 --- a/pythondeps.toml +++ b/pythondeps.toml @@ -19,7 +19,7 @@ [meson] # The install key should match the version in python/wheels/ -meson = { accepted = ">=0.63.0", installed = "1.2.3", canary = "meson" } +meson = { accepted = ">=1.1.0", installed = "1.2.3", canary = "meson" } [docs] # Please keep the installed versions in sync with docs/requirements.txt diff --git a/tcg/meson.build b/tcg/meson.build index ffbe754d8b..165e773abb 100644 --- a/tcg/meson.build +++ b/tcg/meson.build @@ -36,7 +36,8 @@ libtcg_user = static_library('tcg_user', c_args: '-DCONFIG_USER_ONLY', build_by_default: false) -tcg_user = declare_dependency(link_with: libtcg_user) +tcg_user = declare_dependency(objects: libtcg_user.extract_all_objects(recursive: false), + dependencies: tcg_ss.dependencies()) user_ss.add(tcg_user) libtcg_system = static_library('tcg_system', @@ -46,5 +47,6 @@ libtcg_system = static_library('tcg_system', c_args: '-DCONFIG_SOFTMMU', build_by_default: false) -tcg_system = declare_dependency(link_with: libtcg_system) +tcg_system = declare_dependency(objects: libtcg_system.extract_all_objects(recursive: false), + dependencies: tcg_ss.dependencies()) system_ss.add(tcg_system) diff --git a/tests/qtest/libqos/meson.build b/tests/qtest/libqos/meson.build index 558eb4c24b..05fe57a4b9 100644 --- a/tests/qtest/libqos/meson.build +++ b/tests/qtest/libqos/meson.build @@ -72,4 +72,4 @@ libqos = static_library('qos', libqos_srcs + genh, name_suffix: 'fa', build_by_default: false) -qos = declare_dependency(link_whole: libqos) +qos = declare_dependency(objects: libqos.extract_all_objects(recursive: false))