[PATCHv2 5/6] jump label: detect %c support for ARM
From: Rabin Vincent <hidden>
Date: 2012-01-28 13:37:22
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Some versions of ARM GCC which do support asm goto, have problems handling the the %c specifier. Since we need the %c to support jump labels on ARM, detect that too in the asm goto detection script to avoid build errors with these versions. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 Cc: Jason Baron <redacted> Cc: linux-kernel at vger.kernel.org Signed-off-by: Rabin Vincent <redacted> --- scripts/gcc-goto.sh | 18 +++++++++++++++++- 1 files changed, 17 insertions(+), 1 deletions(-)
diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh
index 98cffcb..9b744de 100644
--- a/scripts/gcc-goto.sh
+++ b/scripts/gcc-goto.sh@@ -2,4 +2,20 @@ # Test for gcc 'asm goto' support # Copyright (C) 2010, Jason Baron <jbaron@redhat.com> -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +int main(void) +{ +#ifdef __arm__ + /* + * Not related to asm goto, but used by jump label + * and broken on some ARM GCC versions (see GCC Bug 48637). + */ + static struct { int dummy; int state; } tp; + asm ("@ %c0" :: "i" (&tp.state)); +#endif + +entry: + asm goto ("" :::: entry); + return 0; +} +END
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1.7.8.3