From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yann E. MORIN Date: Mon, 25 Jan 2016 19:42:57 +0100 Subject: [Buildroot] [PATCH 05/21] icu: remove BR2_ARCH_HAS_ATOMICS dependency In-Reply-To: <1453676887-31236-6-git-send-email-thomas.petazzoni@free-electrons.com> References: <1453676887-31236-1-git-send-email-thomas.petazzoni@free-electrons.com> <1453676887-31236-6-git-send-email-thomas.petazzoni@free-electrons.com> Message-ID: <20160125184257.GF3386@free.fr> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Thomas, All, On 2016-01-25 00:07 +0100, Thomas Petazzoni spake thusly: > The BR2_ARCH_HAS_ATOMICS was added because on ARC, atomic instructions > may not be provided by the architecture and therefore the compiler > does not provide the __sync_*() built-ins. > > However, since then, icu was changed and is now able to use C++11 > atomics, or even no atomic operations at all. In fact, icu will: > > * If possible, it will use C++11 atomics, which internally rely on > the __atomic built-ins. These are available since gcc 4.7, and all > architectures provide it. On some architectures, you *must* link > with libatomic, on some other architectures, they are available > built-in, but in all cases, linking against libatomic does not > harm. Thanks to this, even ARC with no atomic support (which was > the original reason for adding the BR2_ARCH_HAS_ATOMICS) dependency > builds fine, provided -latomic is added to LIBS. > > * If C++11 atomics are not available, then it falls back to > __sync_*() built-ins, which allows compilers older than 4.7 to be > supported. > > * If really no atomic mechanism is available, then it falls back to a > basic implementation based on a mutex. > > Conclusion: > > - The BR2_ARCH_HAS_ATOMICS dependency is no longer needed. > > - We need to link with -latomic when gcc >= 4.7 is used. > > Note that reverse dependencies of icu are also changed accordingly. > > Signed-off-by: Thomas Petazzoni Reviewed-by: "Yann E. MORIN" Regards, Yann E. MORIN. > --- > package/beecrypt/Config.in | 2 -- > package/cppcms/Config.in | 1 - > package/icu/Config.in | 2 -- > package/icu/icu.mk | 8 ++++++++ > package/php/Config.ext | 2 -- > package/qt-webkit-kiosk/Config.in | 1 - > package/qt5/qt5base/Config.in | 1 - > package/qt5/qt5webkit/Config.in | 1 - > 8 files changed, 8 insertions(+), 10 deletions(-) > > diff --git a/package/beecrypt/Config.in b/package/beecrypt/Config.in > index fc93a77..069f3d5 100644 > --- a/package/beecrypt/Config.in > +++ b/package/beecrypt/Config.in > @@ -16,7 +16,6 @@ config BR2_PACKAGE_BEECRYPT_CPP > depends on BR2_INSTALL_LIBSTDCPP > depends on BR2_USE_WCHAR # icu > depends on !BR2_BINFMT_FLAT # icu > - depends on BR2_ARCH_HAS_ATOMICS # icu > depends on !BR2_STATIC_LIBS > select BR2_PACKAGE_ICU > help > @@ -24,7 +23,6 @@ config BR2_PACKAGE_BEECRYPT_CPP > > comment "C++ support needs a toolchain w/ C++, wchar, dynamic libraries" > depends on !BR2_BINFMT_FLAT > - depends on BR2_ARCH_HAS_ATOMICS > depends on !BR2_INSTALL_LIBSTDCPP || !BR2_USE_WCHAR \ > || BR2_STATIC_LIBS > > diff --git a/package/cppcms/Config.in b/package/cppcms/Config.in > index 85ba118..79f5474 100644 > --- a/package/cppcms/Config.in > +++ b/package/cppcms/Config.in > @@ -26,7 +26,6 @@ if BR2_PACKAGE_CPPCMS > config BR2_PACKAGE_CPPCMS_ICU > bool "enable icu support" > depends on !BR2_BINFMT_FLAT # icu > - depends on BR2_ARCH_HAS_ATOMICS # icu > select BR2_PACKAGE_ICU > help > Using ICU allows advanced localization features into CppCMS, > diff --git a/package/icu/Config.in b/package/icu/Config.in > index 4d47c32..d31c1fa 100644 > --- a/package/icu/Config.in > +++ b/package/icu/Config.in > @@ -7,7 +7,6 @@ config BR2_PACKAGE_ICU > # file, and it cannot easily be changed to generate FLAT > # format. > depends on !BR2_BINFMT_FLAT > - depends on BR2_ARCH_HAS_ATOMICS > help > International Components for Unicode. > > @@ -28,6 +27,5 @@ endif > > comment "icu needs a toolchain w/ C++, wchar, threads" > depends on !BR2_BINFMT_FLAT > - depends on BR2_ARCH_HAS_ATOMICS > depends on !BR2_INSTALL_LIBSTDCPP || !BR2_USE_WCHAR || \ > !BR2_TOOLCHAIN_HAS_THREADS > diff --git a/package/icu/icu.mk b/package/icu/icu.mk > index 5604504..7bc7f93 100644 > --- a/package/icu/icu.mk > +++ b/package/icu/icu.mk > @@ -17,6 +17,14 @@ ICU_CONF_OPTS = \ > --with-cross-build=$(HOST_ICU_DIR)/source \ > --disable-samples \ > --disable-tests > + > +# With gcc >= 4.7, icu prefers to use C++11 atomics, which rely on the > +# __atomic builtins. On certain architectures, this requires linking > +# with libatomic. > +ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_4_7),y) > +ICU_CONF_ENV += LIBS="-latomic" > +endif > + > HOST_ICU_CONF_OPTS = \ > --disable-samples \ > --disable-tests \ > diff --git a/package/php/Config.ext b/package/php/Config.ext > index c044e45..ee51030 100644 > --- a/package/php/Config.ext > +++ b/package/php/Config.ext > @@ -207,13 +207,11 @@ config BR2_PACKAGE_PHP_EXT_INTL > depends on BR2_USE_WCHAR > depends on !BR2_BINFMT_FLAT # icu > depends on BR2_TOOLCHAIN_HAS_THREADS # icu > - depends on BR2_ARCH_HAS_ATOMICS # icu > help > Internationalization support > > comment "intl support needs a toolchain w/ C++, wchar, threads" > depends on !BR2_BINFMT_FLAT > - depends on BR2_ARCH_HAS_ATOMICS > depends on !BR2_INSTALL_LIBSTDCPP || !BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS > > config BR2_PACKAGE_PHP_EXT_MBSTRING > diff --git a/package/qt-webkit-kiosk/Config.in b/package/qt-webkit-kiosk/Config.in > index 51383f0..32952d7 100644 > --- a/package/qt-webkit-kiosk/Config.in > +++ b/package/qt-webkit-kiosk/Config.in > @@ -8,7 +8,6 @@ config BR2_PACKAGE_QT_WEBKIT_KIOSK > select BR2_PACKAGE_QT5MULTIMEDIA > depends on !BR2_STATIC_LIBS # qt5webkit > depends on BR2_PACKAGE_QT5_JSCORE_AVAILABLE # qt5webkit > - depends on BR2_ARCH_HAS_ATOMICS # qt5webkit > depends on !BR2_BINFMT_FLAT # qt5webkit > help > Simple kiosk-mode browser powered by Qt5Webkit > diff --git a/package/qt5/qt5base/Config.in b/package/qt5/qt5base/Config.in > index 7cadcb2..64a7f65 100644 > --- a/package/qt5/qt5base/Config.in > +++ b/package/qt5/qt5base/Config.in > @@ -259,7 +259,6 @@ config BR2_PACKAGE_QT5BASE_DBUS > config BR2_PACKAGE_QT5BASE_ICU > bool "Enable ICU support" > select BR2_PACKAGE_ICU > - depends on BR2_ARCH_HAS_ATOMICS # icu > depends on !BR2_BINFMT_FLAT # icu > help > This option enables ICU support in Qt5. This is for example > diff --git a/package/qt5/qt5webkit/Config.in b/package/qt5/qt5webkit/Config.in > index eee82e8..96d97cc 100644 > --- a/package/qt5/qt5webkit/Config.in > +++ b/package/qt5/qt5webkit/Config.in > @@ -9,7 +9,6 @@ config BR2_PACKAGE_QT5WEBKIT > # This module does not support static linking > depends on !BR2_STATIC_LIBS > depends on BR2_PACKAGE_QT5_JSCORE_AVAILABLE > - depends on BR2_ARCH_HAS_ATOMICS # icu > depends on !BR2_BINFMT_FLAT # icu > help > Qt is a cross-platform application and UI framework for > -- > 2.6.4 > > _______________________________________________ > buildroot mailing list > buildroot at busybox.net > http://lists.busybox.net/mailman/listinfo/buildroot -- .-----------------.--------------------.------------------.--------------------. | Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: | | +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ | | +33 223 225 172 `------------.-------: X AGAINST | \e/ There is no | | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. | '------------------------------^-------^------------------^--------------------'