[2.6.4 clang/glibc-2.25.90] implicit declaration of function 'reallocarray' is invalid in C99 #241

elkrejzi · 2017-07-17T18:29:59Z

When built with clang-4.0.1, on system with glibc-2.25.90 (glibc 2.26 development snapshot, current git master), the following is noted during compilation

https://gist.github.com/elkrejzi/baad3a9c0035ef954cbb8e6ce2d635ba

At runtime, while compiling doxygen, flex will crash with the following backtrace

https://gist.github.com/elkrejzi/2f821eab0346ea1d1501dfd0f8c53195

elkrejzi · 2017-07-17T18:39:25Z

Glibc 2.26 will have reallocarray function:

https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=2e0bbbfbf95fc9e22692e93658a6fbdd2d4554da;hp=4f26ef1b67287d1f2c32865f7d79c13abda81915

elkrejzi · 2017-07-17T18:46:27Z

reallocarray is declared in malloc.h on glibc-based system. Simply adding "#include <malloc.h>" to src/flexdef.h fixes the problem for me.

Explorer09 · 2017-07-19T02:46:29Z

@elkrejzi reallocarray prototypes in FreeBSD and OpenBSD are defined in <stdlib.h> (see man pages 1 2 )
Glibc should follow and declare reallocarray prototype in <stdlib.h> as well. Since you're building against a development version of Glibc, there's nothing we could fix in flex's side.

elkrejzi · 2017-07-19T10:13:00Z

@Explorer09 It's unlikely glibc is going to change their behaviour. This is after all, a non-standard function.

elkrejzi · 2017-07-19T10:31:03Z

According to https://sourceware.org/bugzilla/show_bug.cgi?id=21789 you need to define _GNU_SOURCE on glibc systems to use this function via stdlib.h (well, as I said, it's a non-standard function).

Explorer09 · 2017-07-19T11:12:44Z

@elkrejzi I would say thank you for finding that out.
However regarding feature test macros, flex misses many of them, not just _GNU_SOURCE.
The current flex source can pop out many "implicit declaration" warnings when built with gcc -std=c99.
I think that's another issue different from this one.

elkrejzi · 2017-07-19T13:01:16Z

Well, clang defaults to c99 mode for some time now. Doesn't gcc as well?

westes · 2017-07-19T13:03:38Z

Yes, but that is a different issue than this one.

…

On Wednesday, 19 July 2017, 1:01 pm +0000, elkrejzi ***@***.***> wrote: Well, clang defaults to c99 mode for some time now. Doesn't gcc as well? -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: #241 (comment)

-- Will Estes westes575@gmail.com

Explorer09 · 2017-07-19T13:52:28Z

@elkrejzi I mean c99 mode without GNU extensions

This would define _GNU_SOURCE in config.h, enabling the reallocarray() prototype in glibc 2.26+. Fixes westes#241.

This would, e.g. define _GNU_SOURCE in config.h, enabling the reallocarray() prototype in glibc 2.26+ on Linux systems with that version of glibc. Fixes #241.

See westes/flex#241 The problem is fixed in master branch and the workaround could be removed in the next version update.

audio/grip: Linux build fix Revisions pulled up: - audio/grip/Makefile 1.5 - audio/grip/distinfo 1.3 - audio/grip/patches/patch-configure 1.3 --- Module Name: pkgsrc Committed By: triaxx Date: Sun Oct 22 07:55:24 UTC 2017 Modified Files: pkgsrc/audio/grip: Makefile distinfo Added Files: pkgsrc/audio/grip/patches: patch-configure Log Message: Add workaround for fixing build on Linux See westes/flex#241 The problem is fixed in master branch and the workaround could be removed in the next version update.

devel/flex: Linux build fix Revisions pulled up: - devel/flex/Makefile 1.61 --- Module Name: pkgsrc Committed By: triaxx Date: Fri Oct 20 06:22:24 UTC 2017 Modified Files: pkgsrc/devel/flex: Makefile Log Message: Add workaround for fixing build on Linux See westes/flex#241 The problem is fixed in master branch and the workaround could be removed in the next version update.

kevin-osborne · 2018-08-15T07:50:10Z

I just needed to build lede/openwrt on manjaro; fixed it by adding this patch to tools/flex/patches/:

https://github.com/westes/flex/commit/24fd0551333e7eded87b64dd36062da3df2f6380.patch