Backport host gcc 15/16 build fixes (m4, gmp, gcc) to 2025.02-op-build#40
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runlevel5 wants to merge 3 commits into
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Backport host gcc 15/16 build fixes (m4, gmp, gcc) to 2025.02-op-build#40runlevel5 wants to merge 3 commits into
runlevel5 wants to merge 3 commits into
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When using host gcc 15, host-gmp fails at configure time with
error message:
configure: error: could not find a working compiler, see config.log for details
The error is due to the macro GMP_PROG_CC_WORKS in the file
acinclude.m4 containing C-code declaring functions without declaring
its parameters. This construct is now an error in C23, which is the
new default in gcc 15. See:
https://gcc.gnu.org/gcc-15/porting_to.html#c23
This commit fixes the issue by adding a package patch from
upstream changesets, not yet published in a release.
Even if gcc 15 is not yet included in Buildroot, this commit also
sets _AUTORECONF = YES for the target package in order to have this
package already fixed.
Fixes:
https://autobuild.buildroot.org/results/623634fa7bbeceeb6d90b15ce0abb1b9b4b24045/
Tested-by: Brigham Campbell <me@brighamcampbell.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit 31569bc)
When compiling host-m4 1.4.19 with host gcc >= 15 (default on Fedora 42+
/ Ubuntu 25.10+), the build fails because gcc 15 changed its default C
standard from gnu17 to gnu23, which the gnulib copy bundled in m4 1.4.19
does not detect properly:
gl_oset.h:275:40: error: expected identifier or '(' before 'int'
Force the previous default -std=gnu17 for the host-m4 build.
This is a backport of upstream commit 7a07a9d ("package/m4: fix build
failure with host-gcc 15"), applied unconditionally because the 2025.02
branch does not have the BR2_HOST_GCC_AT_LEAST_15 symbol used upstream;
-std=gnu17 is a no-op on gcc < 15 (the option exists since gcc 8).
Signed-off-by: Trung Le <8@tle.id.au>
Building gcc 13.3.0 with a host gcc 16 fails because gcc 16 defaults to a
newer C++ standard in which u8"" literals are char8_t, which libcody and
the gcc build system do not handle:
libcody/buffer.cc:348:39: error: no matching function for call to
'S2C(const char8_t [2])'
Backport the two upstream patches that fix this (from buildroot commit
10ccbe079c "package/gcc: fix gcc-13 build with host gcc 16", which carries
them in package/gcc/13.4.0/): a libcody fix to build under C++11..C++26,
and an include-order fix in gcc/system.h. Numbered 0006/0007 to sit after
the existing 13.3.0 patch series.
Signed-off-by: Trung Le <8@tle.id.au>
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Building op-build natively on a modern host (e.g. Fedora 44 / gcc 16, or Ubuntu 26.04 / gcc 15.2) fails in the host-tool / cross-toolchain layer, because gcc ≥ 15 defaults to
-std=gnu23(C23) and gcc 16 defaults to a newer C++ standard. These fixes already exist in upstream buildroot but are not in the2025.02LTS branch this fork is based on.This backports the three needed fixes so the toolchain builds under gcc 16:
package/gmpacinclude.m4(GMP_PROG_CC_WORKS) for C23 — otherwise configure reports "could not find a working compiler". Cherry-pick of upstream31569bcc1b.package/m4-std=gnu17for host-m4 (bundled gnulib breaks under gnu23). Backport of7a07a9d155, applied unconditionally since 2025.02 lacksBR2_HOST_GCC_AT_LEAST_15.package/gccchar8_t/ include-order fixes for building gcc with host gcc 16. The two patches from upstream10ccbe079c(carried in13.4.0/), added to13.3.0/.Testing
With these three commits on
2025.02-op-build, a native blackbird build on a Fedora 44 host (gcc 16, binutils 2.46) gets the full host/cross toolchain to build (host-m4 → gmp/mpfr/mpc → host-gcc-initial 13.3.0), where it previously failed at host-m4. Build then proceeds into target userspace.Alternative considered: bumping m4 to 1.4.20 (upstream
d9aabc1af3) instead of the workaround — kept the minimal-std=gnu17form to match the stable-backport intent.