Build error with tinydir inlining

[reinerh]

On Ubuntu build servers the build fails with this error:

[ 32%] Building C object src/cdogs/CMakeFiles/cdogs.dir/campaigns.c.o
cd /<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/src/cdogs && /usr/bin/cc -DSTATIC -I/<<PKGBUILDDIR>>/src -I/<<PKGBUILDDIR>>/src/cdogs -I/<<PKGBUILDDIR>>/src/. -I/<<PKGBUILDDIR>>/src/proto/nanopb -I/<<PKGBUILDDIR>>/src/cdogs/.. -isystem /usr/include/SDL2 -g -O2 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -ffile-prefix-map=/<<PKGBUILDDIR>>=. -flto=auto -ffat-lto-objects -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -fdebug-prefix-map=/<<PKGBUILDDIR>>=/usr/src/cdogs-sdl-1.5.0+dfsg-1 -Wdate-time -D_FORTIFY_SOURCE=3 -I/usr/include/nanopb -g   -fsigned-char -Wall -W -Wstrict-prototypes -Wpointer-arith -Wcast-qual -g -freg-struct-return -std=gnu99 -Wshadow -Wimplicit-fallthrough=0 -Wno-error=format-overflow -Winline -Werror -MD -MT src/cdogs/CMakeFiles/cdogs.dir/campaigns.c.o -MF CMakeFiles/cdogs.dir/campaigns.c.o.d -o CMakeFiles/cdogs.dir/campaigns.c.o -c /<<PKGBUILDDIR>>/src/cdogs/campaigns.c
In file included from /<<PKGBUILDDIR>>/src/cdogs/campaigns.c:33:
In function ‘tinydir_open_sorted’,
    inlined from ‘LoadCampaignsFromFolder’ at /<<PKGBUILDDIR>>/src/cdogs/campaigns.c:248:6:
/<<PKGBUILDDIR>>/src/tinydir/tinydir.h:265:5: error: inlining failed in call to ‘tinydir_open’: --param max-inline-insns-single limit reached [-Werror=inline]
  265 | int tinydir_open(tinydir_dir *dir, const _tinydir_char_t *path)
      |     ^~~~~~~~~~~~
/<<PKGBUILDDIR>>/src/tinydir/tinydir.h:360:13: note: called from here
  360 |         if (tinydir_open(dir, path) == -1)
      |             ^~~~~~~~~~~~~~~~~~~~~~~
/<<PKGBUILDDIR>>/src/tinydir/tinydir.h:265:5: error: inlining failed in call to ‘tinydir_open’: --param max-inline-insns-single limit reached [-Werror=inline]
  265 | int tinydir_open(tinydir_dir *dir, const _tinydir_char_t *path)
      |     ^~~~~~~~~~~~
/<<PKGBUILDDIR>>/src/tinydir/tinydir.h:374:29: note: called from here
  374 |         if (n_files == 0 || tinydir_open(dir, path) == -1)
      |                             ^~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[3]: *** [src/cdogs/CMakeFiles/cdogs.dir/build.make:331: src/cdogs/CMakeFiles/cdogs.dir/campaigns.c.o] Error 1

In CMakeLists.txt -Werror and -Winline are set:

cdogs-sdl/CMakeLists.txt

Line 131 in 92490cc

add_definitions(-Winline -Werror)

tinydir_open is declared as:

_TINYDIR_FUNC
int tinydir_open(tinydir_dir *dir, const _tinydir_char_t *path);

where _TINYDIR_FUNC is:

# define _TINYDIR_FUNC static inline

I'm not sure why it fails on Ubuntu, but succeeds on Debian builds (and also on CI builds here on Github). (maybe related to --param max-inline-insns-single limit reached that could be different?)

Is there a reason why the build explicitely sets -Winline and upgrades these warnings to errors?

[cxong]

we enable most warnings and set as error in order to be more strict. Is this something that can be fixed upstream in tinydir? Are its functions too big to inline?

[reinerh]

I just compared the build flags between Debian and Ubuntu and found that the difference that causes the problem is -D_FORTIFY_SOURCE=. In Debian that is set to 2 and in Ubuntu to 3.
When I change it in the Debian build to 3, I get the same error.
I guess that with a better fortification the code is also getting a bit larger and it reaches the inlining instructions limit.
It probably should be addressed in tinydir upstream. For the cdogs-sdl package, I'll check if I can raise the limit.

[reinerh]

When I raise the inlining limit (-finline-limit=1000), the build continues but fails later with:

src/cdogs/utils.c: In function ‘RelPathFromCWD’:
src/cdogs/utils.c:152:17: error: ‘__builtin___strncat_chk’ output may be truncated copying 4095 bytes from a string of length 4095 [-Werror=stringop-truncation]
  152 |                 strncat(srcBuf, src, CDOGS_PATH_MAX - 1);
      |                 ^
src/cdogs/utils.c: In function ‘GetDataFilePath’:
src/cdogs/utils.c:152:17: error: ‘__builtin___strncat_chk’ output may be truncated copying 4095 bytes from a string of length 4095 [-Werror=stringop-truncation]

(this check also seems to come from -D_FORTIFY_SOURCE=3)

When I ignore that with -Wno-stringop-truncation the build succeeds.

[reinerh]

Nix is disabling fortifying with level 3:

https://github.com/NixOS/nixpkgs/blob/5863c27340ba4de8f83e7e3c023b9599c3cb3c80/pkgs/games/cdogs-sdl/default.nix#L53-L54

Gentoo, FreeBSD and OpenMandriva are patching out -Werror:
https://gitweb.gentoo.org/repo/gentoo.git/tree/games-arcade/cdogs-sdl/files/cdogs-sdl-1.1.1-cmake.patch
https://cgit.freebsd.org/ports/tree/games/cdogs-sdl/files/patch-CMakeLists.txt
https://github.com/OpenMandrivaAssociation/cdogs-sdl/blob/master/cdogs-sdl-disable-werror.patch

[cxong]

which version of ubuntu/gcc runs into this error?

• from build logs, it's ubuntu 20.04 gcc GNU 13.2.0

[reinerh]

Yes, 13.2.0, same on Debian unstable.

[reinerh]

After increasing the inline limit and ignoring stringop-truncation errors in the 2.0.0 Debian package, it also successfully built in Ubuntu and it made it just in time before the freeze for 24.04 LTS. 😄