name : gcc-check-fpatchable-function-entry.sh #!/bin/bash # SPDX-License-Identifier: GPL-2.0 set -e set -o pipefail # To debug, uncomment the following line # set -x # Output from -fpatchable-function-entry can only vary on ppc64 elfv2, so this # should not be invoked for other targets. Therefore we can pass in -m64 and # -mabi explicitly, to take care of toolchains defaulting to other targets. # Test whether the compile option -fpatchable-function-entry exists and # generates appropriate code echo "int func() { return 0; }" | \ $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2 - -o - 2> /dev/null | \ grep -q "__patchable_function_entries" # Test whether nops are generated after the local entry point echo "int x; int func() { return x; }" | \ $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2 - -o - 2> /dev/null | \ awk 'BEGIN { RS = ";" } /\.localentry.*nop.*\n[[:space:]]*nop/ { print $0 }' | \ grep -q "func:" exit 0