From 6b4ece5af75554a1709b88a9aa7fb5f48112f970 Mon Sep 17 00:00:00 2001 From: Hongxu Jia Date: Tue, 5 Mar 2013 10:50:15 +0800 Subject: [PATCH] sanity.bbclass:check if necessary to add march to BUILD_CFLAGS 1, There are a set of GCC built-in functions for atomic memory access. The definition given in the Intel documentation allows only for the use of the types int, long, long long as well as their unsigned counterparts. GCC will allow any integral scalar or pointer type that is 1, 2, 4, 8 or 16 bytes in length, suffix `_n' where n is the size of the data type.Such as: __sync_fetch_and_add_n __sync_fetch_and_sub_n __sync_fetch_and_or_n __sync_fetch_and_and_n __sync_fetch_and_xor_n __sync_fetch_and_nand_n The above builtins are intended to be compatible with those described in the Intel Itanium Processor-specific Application Binary Interface, section 7.4. 2, The glib-2.0-native and qemu-native invoke the above builtin function with suffix `_4', and glib-2.0-native uses __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 to test the existance. 3, Not all above builtin functions are supported by all target processors.Such as i386 does not support the functions with suffix `_4', but i486 or later support. 4, Prior to GCC 4.5, on the Intel's processor, the default arch is i386 unless GCC is built with the --with-arch switch. Since GCC 4.5 the default arch is implied by the target. 5, If your host GCC is older than 4.5 and it is built without the --with-arch switch, when you use the GCC to compile target, you should specify -march to tell GCC what the target's arch is, otherwise i386 is used as default. Above all, when use older GCC to compile glib-2.0-native or glib-2.0-native, and the GCC incorrectly uses i386 as default, the above builtin function with suffix `_4' is not referenced. We should have a check in sanity.bbclass to tell the user if necessary to add march to BUILD_CFLAGS in this situation. http://gcc.gnu.org/onlinedocs/gcc-4.7.2/gcc/_005f_005fsync-Builtins.html#_005f_005fsync-Builtins http://gcc.gnu.org/ml/gcc-help/2009-06/msg00037.html http://gcc.gnu.org/gcc-4.5/changes.html http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47460 http://llvm.org/bugs/show_bug.cgi?id=11174 http://download.intel.com/design/itanium/downloads/245370.pdf [YOCTO #3563] (From OE-Core rev: 38042ed8586b3abe427af33debc2402caeca52cb) Signed-off-by: Hongxu Jia Signed-off-by: Saul Wold Signed-off-by: Richard Purdie --- meta/classes/sanity.bbclass | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/meta/classes/sanity.bbclass b/meta/classes/sanity.bbclass index 06e95e3..8cdb06e 100644 --- a/meta/classes/sanity.bbclass +++ b/meta/classes/sanity.bbclass @@ -309,6 +309,31 @@ def check_sanity_validmachine(sanity_data): return messages +# Checks if necessary to add option march to host gcc +def check_gcc_march(sanity_data): + result = False + + # Check if -march not in BUILD_CFLAGS + if sanity_data.getVar("BUILD_CFLAGS",True).find("-march") < 0: + + # Construct a test file + f = file("gcc_test.c", "w") + f.write("int main (){ __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4; return 0;}\n") + f.close() + import commands + + # Check if GCC could work without march + status,result = commands.getstatusoutput("${BUILD_PREFIX}gcc gcc_test.c -o gcc_test") + if status != 0: + # Check if GCC could work with march + status,result = commands.getstatusoutput("${BUILD_PREFIX}gcc -march=native gcc_test.c -o gcc_test") + if status == 0: + result = True + + os.remove("gcc_test.c") + os.remove("gcc_test") + + return result def check_sanity(sanity_data): import subprocess @@ -416,6 +441,10 @@ def check_sanity(sanity_data): if not check_app_exists("qemu-arm", sanity_data): messages = messages + "qemu-native was in ASSUME_PROVIDED but the QEMU binaries (qemu-arm) can't be found in PATH" + if check_gcc_march(sanity_data): + messages = messages + "Your gcc version is older than 4.5, please add the following param to local.conf\n \ + BUILD_CFLAGS_append = \" -march=native\"\n" + paths = sanity_data.getVar('PATH', True).split(":") if "." in paths or "" in paths: messages = messages + "PATH contains '.' or '' (empty element), which will break the build, please remove this.\n" -- 2.7.4