linux-stable/tools/build/feature/test-libbpf-bpf_object__next_map.c

// SPDX-License-Identifier: GPL-2.0
#include <bpf/libbpf.h>

int main(void)
{
	bpf_object__next_map(NULL /* obj */, NULL /* prev */);
	return 0;
}
perf build: Stop using __weak bpf_object__next_map() to handle older libbpf versions By adding a feature test for bpf_object__next_map() and providing a fallback if it isn't present in older versions of libbpf. Committer testing: $ rpm -q libbpf-devel libbpf-devel-0.4.0-2.fc35.x86_64 $ make -C tools/perf LIBBPF_DYNAMIC=1 O=/tmp/build/perf install-bin $ cat /tmp/build/perf/feature/test-libbpf-bpf_object__next_map.make.output test-libbpf-bpf_object__next_map.c: In function ‘main’: test-libbpf-bpf_object__next_map.c:6:9: error: implicit declaration of function ‘bpf_object__next_map’; did you mean ‘bpf_object__next’? [-Werror=implicit-function-declaration] 6 \| bpf_object__next_map(NULL /* obj /, NULL / prev */); \| ^~~~~~~~~~~~~~~~~~~~ \| bpf_object__next cc1: all warnings being treated as errors $ $ objdump -dS /tmp/build/perf/perf \| grep '<bpf_object__next_map>:' -A20 00000000005b2e00 <bpf_object__next_map>: { 5b2e00: 55 push %rbp 5b2e01: 48 89 e5 mov %rsp,%rbp 5b2e04: 48 83 ec 10 sub $0x10,%rsp 5b2e08: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax 5b2e0f: 00 00 5b2e11: 48 89 45 f8 mov %rax,-0x8(%rbp) 5b2e15: 31 c0 xor %eax,%eax return bpf_map__next(prev, obj); 5b2e17: 48 8b 45 f8 mov -0x8(%rbp),%rax 5b2e1b: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 5b2e22: 00 00 5b2e24: 75 0f jne 5b2e35 <bpf_object__next_map+0x35> } 5b2e26: c9 leave 5b2e27: 49 89 f8 mov %rdi,%r8 5b2e2a: 48 89 f7 mov %rsi,%rdi return bpf_map__next(prev, obj); 5b2e2d: 4c 89 c6 mov %r8,%rsi 5b2e30: e9 cb b1 e5 ff jmp 40e000 <bpf_map__next@plt> $ Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ian Rogers <irogers@google.com> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 2022-05-24 11:13:17 +00:00			`// SPDX-License-Identifier: GPL-2.0`
			`#include <bpf/libbpf.h>`

			`int main(void)`
			`{`
			`bpf_object__next_map(NULL /* obj /, NULL / prev */);`
			`return 0;`
			`}`