clang macro-redefined warnings in newer kernel versions #3366

Mic92 · 2021-04-20T12:52:19Z

When running on 5.10.29, I get the following warning:

╭─[~/git/vmsh]─[main]
╰─ % sudo profile -F 99 -f > folded
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:45:9: warning: '__HAVE_BUILTIN_BSWAP32__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP32__
        ^
<command line>:4:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP32__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:46:9: warning: '__HAVE_BUILTIN_BSWAP64__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP64__
        ^
<command line>:5:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP64__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:47:9: warning: '__HAVE_BUILTIN_BSWAP16__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP16__
        ^
<command line>:3:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP16__ 1
        ^
3 warnings generated.

This happens for all bcc related tools (we use bcc v0.19.0)

The text was updated successfully, but these errors were encountered:

hhoffstaette · 2021-04-27T19:50:26Z

This can be easily fixed by not warning about macro redefinitions. I've tried it here and it works fine.
I realize this might be contentious since usually macro redefinitions are not intended, but I don't see how this can be fixed in a portable manner.

Mic92 · 2021-04-28T12:09:22Z

Do you plan to propose this in a PR? It certainly improve the situation.

hhoffstaette · 2021-04-28T13:03:18Z

Do you plan to propose this in a PR? It certainly improve the situation.

Can do later today, sure.

Fixes: https://bugs.gentoo.org/783693 iovisor/bcc#3366

davemarchevsky · 2021-04-29T09:27:02Z

Looks like this may be the kernel change causing the warning. In bcc these cflags were first added in e3b3b4c, then moved to their current location in b83ccf3 .

I've been trying to figure out a way to fix this that's more precise than #3385 but as @hhoffstaette mentioned it's not looking straightforward. I think moving the -D defines to proper #defines, gated by a ifndef, in a virtual header included after virtual bpf.h, may work. Trying to validate this approach currently.

As reported in iovisor#3366, on newer kernels bcc complains about macro redefinition when compiling bpf programs: ``` include/linux/compiler-clang.h:46:9: warning: '__HAVE_BUILTIN_BSWAP64__' macro redefined [-Wmacro-redefined] \#define __HAVE_BUILTIN_BSWAP64__ ^ <command line>:5:9: note: previous definition is here \#define __HAVE_BUILTIN_BSWAP64__ 1 ``` Since these macros are passed in as `-D` cflags, they appear first before any \#define statements in code. Since an [upstream kernel patch](https://lore.kernel.org/linux-csky/20210226161151.2629097-1-arnd@kernel.org/) added these defines in a kernel header, we see the warning. This patch moves these definitions to a separate 'virtual' header that's included after virtual_bpf.h and adds an ifndef guard. As a result, newer kernels with the patch will not trigger the warning, while older kernels will not lose the definition. This should be safe based on my digging - some existing bcc programs use `__builtin_bswap` methods, but without checking HAVE_BUILTIN_BSWAP. Macros that may be conditionally defined based on HAVE_BUILTIN_BSWAP, like those in `bpf_endian.h`, aren't. If a similar macro or struct def in virtual_bpf.h - or any header it pulls in - changes depending on HAVE_BUILTIN_BSWAP this could cause problems on older kernels, but I don't believe that this is the case, or will be based on how infrequently the defines are checked.

As reported in #3366, on newer kernels bcc complains about macro redefinition when compiling bpf programs: ``` include/linux/compiler-clang.h:46:9: warning: '__HAVE_BUILTIN_BSWAP64__' macro redefined [-Wmacro-redefined] \#define __HAVE_BUILTIN_BSWAP64__ ^ <command line>:5:9: note: previous definition is here \#define __HAVE_BUILTIN_BSWAP64__ 1 ``` Since these macros are passed in as `-D` cflags, they appear first before any \#define statements in code. Since an [upstream kernel patch](https://lore.kernel.org/linux-csky/20210226161151.2629097-1-arnd@kernel.org/) added these defines in a kernel header, we see the warning. This patch moves these definitions to a separate 'virtual' header that's included after virtual_bpf.h and adds an ifndef guard. As a result, newer kernels with the patch will not trigger the warning, while older kernels will not lose the definition. This should be safe based on my digging - some existing bcc programs use `__builtin_bswap` methods, but without checking HAVE_BUILTIN_BSWAP. Macros that may be conditionally defined based on HAVE_BUILTIN_BSWAP, like those in `bpf_endian.h`, aren't. If a similar macro or struct def in virtual_bpf.h - or any header it pulls in - changes depending on HAVE_BUILTIN_BSWAP this could cause problems on older kernels, but I don't believe that this is the case, or will be based on how infrequently the defines are checked.

l1x · 2021-12-19T22:17:53Z

Is this the same thing?

In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:51:9: warning: '__HAVE_BUILTIN_BSWAP32__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP32__
        ^
<command line>:4:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP32__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:52:9: warning: '__HAVE_BUILTIN_BSWAP64__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP64__
        ^
<command line>:5:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP64__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:53:9: warning: '__HAVE_BUILTIN_BSWAP16__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP16__
        ^
<command line>:3:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP16__ 1

davemarchevsky · 2021-12-19T23:47:36Z

@l1x yeah, looks like the issue is back, or perhaps my earlier fix didn't work, will investigate

l1x · 2021-12-29T23:14:46Z

@l1x yeah, looks like the issue is back, or perhaps my earlier fix didn't work, will investigate

Let me know how can I help.

0xlax · 2022-02-20T14:20:40Z

Still getting a warning on it

In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from ./include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:41:9: warning: '__HAVE_BUILTIN_BSWAP32__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP32__
        ^
<command line>:4:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP32__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from ./include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:42:9: warning: '__HAVE_BUILTIN_BSWAP64__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP64__
        ^
<command line>:5:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP64__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from ./include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:43:9: warning: '__HAVE_BUILTIN_BSWAP16__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP16__
        ^
<command line>:3:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP16__ 1
        ^
3 warnings generated.

amir9339 · 2022-04-15T06:52:44Z

When running sudo opensnoop-bpfcc to test the package installation I got this message as well.
But, the program did run well after it.

In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:41:9: warning: '__HAVE_BUILTIN_BSWAP32__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP32__
        ^
<command line>:4:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP32__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:42:9: warning: '__HAVE_BUILTIN_BSWAP64__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP64__
        ^
<command line>:5:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP64__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:43:9: warning: '__HAVE_BUILTIN_BSWAP16__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP16__
        ^
<command line>:3:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP16__ 1
        ^
3 warnings generated.
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:41:9: warning: '__HAVE_BUILTIN_BSWAP32__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP32__
        ^
<command line>:4:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP32__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:42:9: warning: '__HAVE_BUILTIN_BSWAP64__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP64__
        ^
<command line>:5:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP64__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:80:
include/linux/compiler-clang.h:43:9: warning: '__HAVE_BUILTIN_BSWAP16__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP16__
        ^
<command line>:3:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP16__ 1
        ^
3 warnings generated.

chenhengqi · 2022-04-15T11:09:07Z

I think this problem is fixed by #3391 . Can you give it a try ? @amir9339

amir9339 · 2022-04-15T12:44:31Z

I think this problem is fixed by #3391 . Can you give it a try ? @amir9339

Thanks! Yep, I'll give it a try!

zhangxiang958 · 2022-09-22T08:09:40Z

on ubuntu:22.04, and docker/for-desktop-kernel:5.10.76-505289bcc85427a04d8d797e06cbca92eee291f4, still got this warning:
after run opensnoop-bpfcc

In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:51:9: warning: '__HAVE_BUILTIN_BSWAP32__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP32__
        ^
<command line>:4:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP32__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:52:9: warning: '__HAVE_BUILTIN_BSWAP64__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP64__
        ^
<command line>:5:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP64__ 1
        ^
In file included from <built-in>:2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:53:9: warning: '__HAVE_BUILTIN_BSWAP16__' macro redefined [-Wmacro-redefined]
#define __HAVE_BUILTIN_BSWAP16__
        ^
<command line>:3:9: note: previous definition is here
#define __HAVE_BUILTIN_BSWAP16__ 1
        ^
3 warnings generated.

chenhengqi · 2022-09-22T08:15:50Z

@zhangxiang958 Please build BCC from source.

ayoubeddafali · 2022-09-26T13:35:35Z

This might help someone somewhere, so here is how I solved it after a long struggle :

bpf = BPF(text=program, usdt_contexts=[usdt] if usdt else [], cflags=["-Wno-macro-redefined"])

timchenxiaoyu · 2022-11-26T13:06:20Z

@ayoubeddafali NameError: name 'usdt' is not defined

timchenxiaoyu · 2022-11-26T14:34:28Z

build BCC from source is ok

mYu4N · 2023-01-10T11:15:44Z

kernel version : 5.10.134-12.2
bcc-tools version : 0.19.0-5.0.2

In file included from :2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:51:9: warning: 'HAVE_BUILTIN_BSWAP32' macro redefined [-Wmacro-redefined]
#define HAVE_BUILTIN_BSWAP32
^
:4:9: note: previous definition is here
#define HAVE_BUILTIN_BSWAP32 1
^
In file included from :2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:52:9: warning: 'HAVE_BUILTIN_BSWAP64' macro redefined [-Wmacro-redefined]
#define HAVE_BUILTIN_BSWAP64
^
:5:9: note: previous definition is here
#define HAVE_BUILTIN_BSWAP64 1
^
In file included from :2:
In file included from /virtual/include/bcc/bpf.h:12:
In file included from include/linux/types.h:6:
In file included from include/uapi/linux/types.h:14:
In file included from include/uapi/linux/posix_types.h:5:
In file included from include/linux/stddef.h:5:
In file included from include/uapi/linux/stddef.h:2:
In file included from include/linux/compiler_types.h:69:
include/linux/compiler-clang.h:53:9: warning: 'HAVE_BUILTIN_BSWAP16' macro redefined [-Wmacro-redefined]
#define HAVE_BUILTIN_BSWAP16
^
:3:9: note: previous definition is here
#define HAVE_BUILTIN_BSWAP16 1
^
3 warnings generated.

In order to help others to find the repository, I suggest to include the github repository. I faced an issue with warnings when I tried to install the BCC and I could find the solution by installing the BCC through the source code(iovisor/bcc#3366) . I don't know if it could be useful to include this information here somewhere. Signed-off-by: edualb <39157101+edualb@users.noreply.github.com>

Brings in a newer version of bcc to help with iovisor/bcc#3366. Compiling from source isn't work I wanna do.

hhoffstaette mentioned this issue Apr 28, 2021

Disable -Wmacro-redefined to prevent compilation warnings when running tools #3385

Closed

hhoffstaette added a commit to hhoffstaette/portage that referenced this issue Apr 28, 2021

bcc: fix LLVM_MAX_SLOT for 12 & suppress macro redefinition warnings

9e0ac28

Fixes: https://bugs.gentoo.org/783693 iovisor/bcc#3366

davemarchevsky mentioned this issue Apr 30, 2021

Move HAVE_BUILTIN_BSWAP includes to separate header #3391

Merged

kazuho mentioned this issue Jun 11, 2021

[CI][h2olog] do not return until boot process is complete h2o/h2o#2752

Merged

alban mentioned this issue Jun 24, 2021

bcc tools print warnings about macro redefined inspektor-gadget/inspektor-gadget#182

Closed

chenhengqi closed this as completed Sep 22, 2022

edualb mentioned this issue Apr 2, 2023

Including BCC github repository lizrice/learning-ebpf#8

Merged

yuvipanda added a commit to cryptnono/cryptnono that referenced this issue Oct 31, 2023

image: Bump base image to Ubuntu 23.10

22d566e

Brings in a newer version of bcc to help with iovisor/bcc#3366. Compiling from source isn't work I wanna do.

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clang macro-redefined warnings in newer kernel versions #3366

clang macro-redefined warnings in newer kernel versions #3366

Mic92 commented Apr 20, 2021 •

edited

hhoffstaette commented Apr 27, 2021

Mic92 commented Apr 28, 2021

hhoffstaette commented Apr 28, 2021

davemarchevsky commented Apr 29, 2021

l1x commented Dec 19, 2021

davemarchevsky commented Dec 19, 2021

l1x commented Dec 29, 2021

0xlax commented Feb 20, 2022

amir9339 commented Apr 15, 2022

chenhengqi commented Apr 15, 2022

amir9339 commented Apr 15, 2022

zhangxiang958 commented Sep 22, 2022

chenhengqi commented Sep 22, 2022

ayoubeddafali commented Sep 26, 2022 •

edited

timchenxiaoyu commented Nov 26, 2022

timchenxiaoyu commented Nov 26, 2022

mYu4N commented Jan 10, 2023

clang macro-redefined warnings in newer kernel versions #3366

clang macro-redefined warnings in newer kernel versions #3366

Comments

Mic92 commented Apr 20, 2021 • edited

hhoffstaette commented Apr 27, 2021

Mic92 commented Apr 28, 2021

hhoffstaette commented Apr 28, 2021

davemarchevsky commented Apr 29, 2021

l1x commented Dec 19, 2021

davemarchevsky commented Dec 19, 2021

l1x commented Dec 29, 2021

0xlax commented Feb 20, 2022

amir9339 commented Apr 15, 2022

chenhengqi commented Apr 15, 2022

amir9339 commented Apr 15, 2022

zhangxiang958 commented Sep 22, 2022

chenhengqi commented Sep 22, 2022

ayoubeddafali commented Sep 26, 2022 • edited

timchenxiaoyu commented Nov 26, 2022

timchenxiaoyu commented Nov 26, 2022

mYu4N commented Jan 10, 2023

Mic92 commented Apr 20, 2021 •

edited

ayoubeddafali commented Sep 26, 2022 •

edited