[Clfs-support] CLFS Embedded has build error when build gcc on Ubuntu 19.04

[Andrew Bradford]

Hi,

On Mon, Oct 14, 2019 at 11:27 AM DELUGE <deluge at 52loli.vip> wrote:
> When I build gcc 6.2 following http://clfs.org/view/clfs-embedded/x86/cross-tools/gcc-static.html on Ubuntu 19.04 using gcc 8.3,
> The error below occurred. Can anyone tell me how can I resolve this problem? Thanks.
>
> make[1]: Nothing to be done for 'all'.
> make[1]: Leaving directory '/mnt/clfs/sources/gcc-build/fixincludes'
> make[1]: Entering directory '/mnt/clfs/sources/gcc-build/gcc'
> g++ -fno-PIE -c   -g -O2 -DIN_GCC  -DCROSS_DIRECTORY_STRUCTURE   -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings   -DHAVE_CONFIG_H -I. -I. -I../../gcc-6.2.0/gcc -I../../gcc-6.2.0/gcc/. -I../../gcc-6.2.0/gcc/../include -I../../gcc-6.2.0/gcc/../libcpp/include -I/mnt/clfs/sources/gcc-build/./gmp -I/mnt/clfs/sources/gcc-6.2.0/gmp -I/mnt/clfs/sources/gcc-build/../gcc-6.2.0/mpfr/src -I/mnt/clfs/sources/gcc-6.2.0/mpc/src  -I../../gcc-6.2.0/gcc/../libdecnumber -I../../gcc-6.2.0/gcc/../libdecnumber/dpd -I../libdecnumber -I../../gcc-6.2.0/gcc/../libbacktrace   -o ubsan.o -MT ubsan.o -MMD -MP -MF ./.deps/ubsan.TPo ../../gcc-6.2.0/gcc/ubsan.c
> ../../gcc-6.2.0/gcc/ubsan.c: In function 'bool ubsan_use_new_style_p(location_t)':
> ../../gcc-6.2.0/gcc/ubsan.c:1472:23: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
>        || xloc.file == '\0' || xloc.file[0] == '\xff'
>                        ^~~~
> make[1]: *** [Makefile:1085: ubsan.o] Error 1
> make[1]: Leaving directory '/mnt/clfs/sources/gcc-build/gcc'
> make: *** [Makefile:4121: all-gcc] Error 2

Newer versions of GCC have different default settings for what is
considered an error or a warning as compared to older versions of GCC.
I believe that GCC releases from version 7 onwards will hit this issue
when building GCC 6.3.

I believe that newer releases of GCC version 6 (like version 6.4 or
6.5) should fix this.  You could try using a newer version of GCC 6.
Or you can have a try at applying this patch from OpenEmbedded:
https://patchwork.openembedded.org/patch/138884/

Sorry, I don't have a better or more detailed answer for you right now.
Thanks,
Andrew