https://github.com/torvalds/linux
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Tip revision: 4d856f72c10ecb060868ed10ff1b1453943fc6c8 authored by Linus Torvalds on 15 September 2019, 21:19:32 UTC
Linux 5.3
Tip revision: 4d856f7
gcc-check-mprofile-kernel.sh
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0

set -e
set -o pipefail

# To debug, uncomment the following line
# set -x

# -mprofile-kernel is only supported on 64le, so this should not be invoked
# for other targets. Therefore we can pass in -m64 and -mlittle-endian
# explicitly, to take care of toolchains defaulting to other targets.

# Test whether the compile option -mprofile-kernel exists and generates
# profiling code (ie. a call to _mcount()).
echo "int func() { return 0; }" | \
    $* -m64 -mlittle-endian -S -x c -O2 -p -mprofile-kernel - -o - \
    2> /dev/null | grep -q "_mcount"

# Test whether the notrace attribute correctly suppresses calls to _mcount().

echo -e "#include <linux/compiler.h>\nnotrace int func() { return 0; }" | \
    $* -m64 -mlittle-endian -S -x c -O2 -p -mprofile-kernel - -o - \
    2> /dev/null | grep -q "_mcount" && \
    exit 1

exit 0
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