[Buildroot] [PATCH 05/21] icu: remove BR2_ARCH_HAS_ATOMICS dependency
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Sun Jan 24 23:07:51 UTC 2016
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 <thomas.petazzoni at free-electrons.com>
---
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
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