Bug 870082 – media-radio/fldigi-4.1.23 fails to compile (MUSL): table.cxx:49:18: error: NULL was not declared in this scope

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Agostino Sarubbo 2022-09-14 10:25:19 UTC]

https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/

Issue: media-radio/fldigi-4.1.23 fails to compile (MUSL).
Discovered on: amd64 (internal ref: tinderbox_musl)

NOTE:
This machine uses MUSL libc

[Comment 1 Agostino Sarubbo 2022-09-14 10:25:21 UTC]

Created attachment 805087 [details]
build.log

build log and emerge --info

[Comment 2 Thomas Beierlein 2022-09-16 17:56:27 UTC]

Weird. A MUSL related bug has been solved already (#832231). The code afterwards build without problems under MUSL. Now it magically fails. 

At the moment I do not see what has changed in between. Needs to investigate some more.

[Comment 3 Sam James 2022-09-16 18:01:01 UTC]

This kind of one could easily be gcc 11 vs 12, but only appearing on musl. Just a missing include hopefully.

[Comment 4 Thomas Beierlein 2022-09-16 20:08:03 UTC]

(In reply to Sam James from comment #3)
> This kind of one could easily be gcc 11 vs 12, but only appearing on musl.

I will have to  check whats the difference between both. Some defaults may have changed.

> Just a missing include hopefully.

No, looks a little bit more complicated.

The log show a

#define nullptr NULL

from one of the source files, but an additional

#define NULL nullptr 

from included time.h

When commenting out the first (conditional) definition the code compiles.

Maybe it is related to the different handling of the NULL macro in glibc and musl.

[Comment 5 Thomas Beierlein 2022-09-16 20:19:27 UTC]

(In reply to Thomas Beierlein from comment #4)
> (In reply to Sam James from comment #3)
> > This kind of one could easily be gcc 11 vs 12, but only appearing on musl.
> 
> I will have to  check whats the difference between both. Some defaults may
> have changed.
> 
Hmm, looks not like GCC11 vs. GCC12 related. Fails to compile even under GCC-11.3.0

[Comment 6 Thomas Beierlein 2022-09-17 10:18:28 UTC]

Turns out, the problem is a change in definition of NULL in musl-1.2.3. See teh following commit: 

https://git.musl-libc.org/cgit/musl/commit?id=98e688a9da5e7b2925dda17a2d6820dddf1fb287

-#ifdef __cplusplus
+#if __cplusplus >= 201103L
+#define NULL nullptr
+#elif defined(__cplusplus)
 #define NULL 0L
 #else
 #define NULL ((void*)0)


As fldigi has a

#define nullptr NULL 

it results in a circular redefinition.

So but is not related to GCC12

[Comment 7 Larry the Git Cow 2022-09-17 12:12:15 UTC]

The bug has been closed via the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=2d149b09fb7c013457a0c866a3a6a4f9e72c3ee3

commit 2d149b09fb7c013457a0c866a3a6a4f9e72c3ee3
Author:     Thomas Beierlein <[e-mail]>
AuthorDate: 2022-09-17 12:11:20 +0000
Commit:     Thomas Beierlein <[e-mail]>
CommitDate: 2022-09-17 12:11:20 +0000

    media-radio/fldigi: Drop problematic definition of nullptr
    
    Closes: https://bugs.gentoo.org/870082
    Signed-off-by: Thomas Beierlein <[e-mail]>

 .../files/fldigi-drop-nullptr-definition.patch     | 23 ++++++++++++++++++++++
 media-radio/fldigi/fldigi-4.1.22.ebuild            |  3 ++-
 media-radio/fldigi/fldigi-4.1.23.ebuild            |  3 ++-
 3 files changed, 27 insertions(+), 2 deletions(-)