gcc 9.0.0 build issues

[Petr Lautrbach <plautrba@redhat.com>]

gcc-9.0.0-0.3.fc30.x86_64 from Fedora Rawhide:

gcc version 9.0.0 20190119 (Red Hat 9.0.0-0.3) (GCC)

$ make DESTDIR=~/obj install install-pywrap
...

make[2]: Entering directory 
'/home/build/SELinuxProject-selinux/libsepol/src'
cc -O2 -Werror -Wall -Wextra -Wmissing-format-attribute 
-Wmissing-noreturn -Wpointer-arith -Wshadow -Wstrict-prototypes 
-Wundef -Wunused -Wwrite-strings -I. -I../include -D_GNU_SOURCE 
-I../cil/include -fPIC -c -o genbools.o genbools.c
In function ‘strtrim’,
    inlined from ‘process_boolean.constprop’ at genbools.c:52:2:
genbools.c:24:2: error: ‘strncpy’ output may be truncated copying 
8191 bytes from a string of length 8191 
[-Werror=stringop-truncation]
   24 |  strncpy(dest, ptr, size);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~

...

make[2]: Entering directory 
'/home/build/SELinuxProject-selinux/libsepol/src'
cc -O2 -Werror -Wall -Wextra -Wmissing-format-attribute 
-Wmissing-noreturn -Wpointer-arith -Wshadow -Wstrict-prototypes 
-Wundef -Wunused -Wwrite-strings -I. -I../include -D_GNU_SOURCE 
-I../cil/include -fPIC -DSHARED -c -o genbools.lo genbools.c
In function ‘strtrim’,
    inlined from ‘process_boolean.constprop’ at genbools.c:52:2:
genbools.c:24:2: error: ‘strncpy’ output may be truncated copying 
8191 bytes from a string of length 8191 
[-Werror=stringop-truncation]
   24 |  strncpy(dest, ptr, size);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~

...

make[2]: Entering directory 
'/home/build/SELinuxProject-selinux/libselinux/src'
cc -O2 -Werror -Wall -Wextra -Wmissing-format-attribute 
-Wmissing-noreturn -Wpointer-arith -Wshadow -Wstrict-prototypes 
-Wundef -Wunused -Wwrite-strings -I../include -D_GNU_SOURCE 
-DNO_ANDROID_BACKEND   -c -o booleans.o booleans.c
In function ‘strtrim’,
    inlined from ‘process_boolean’ at booleans.c:362:2:
booleans.c:335:2: error: ‘strncpy’ output may be truncated copying 
between 8188 and 8191 bytes from a string of length 8191 
[-Werror=stringop-truncation]
  335 |  strncpy(dest, ptr, size);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~

...



When libselinux is built separately, other CFLAGS is used:

$ cd libselinux

$ make DESTDIR=~/obj install install-pywrap
...

make[1]: Entering directory 
'/home/build/SELinuxProject-selinux/libselinux/src'

cc -O -Wall -W -Wundef -Wformat-y2k -Wformat-security -Winit-self 
-Wmissing-include-dirs -Wunused -Wunknown-pragmas 
-Wstrict-aliasing -Wshadow -Wpointer-arith -Wbad-function-cast 
-Wcast-align -Wwrite-strings -Waggregate-return 
-Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes 
-Wmissing-declarations -Wmissing-noreturn 
-Wmissing-format-attribute -Wredundant-decls -Wnested-externs 
-Winline -Winvalid-pch -Wvolatile-register-var 
-Wdisabled-optimization -Wbuiltin-macro-redefined -Wattributes 
-Wmultichar -Wdeprecated-declarations -Wdiv-by-zero 
-Wdouble-promotion -Wendif-labels -Wextra -Wformat-extra-args 
-Wformat-zero-length -Wformat=2 -Wmultichar -Woverflow 
-Wpointer-to-int-cast -Wpragmas -Wno-missing-field-initializers 
-Wno-sign-compare -Wno-format-nonliteral -Wframe-larger-than=32768 
-fstack-protector-all --param=ssp-buffer-size=4 -fexceptions 
-fasynchronous-unwind-tables -fdiagnostics-show-option 
-funit-at-a-time -Werror -Wno-aggregate-return 
-Wno-redundant-decls -fipa-pure-const -Wlogical-op 
-Wpacked-bitfield-compat -Wsync-nand -Wcoverage-mismatch -Wcpp 
-Wformat-contains-nul -Wnormalized=nfc -Wsuggest-attribute=const 
-Wsuggest-attribute=noreturn -Wsuggest-attribute=pure 
-Wtrampolines -Wjump-misses-init -Wno-suggest-attribute=pure 
-Wno-suggest-attribute=const -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 
-Wstrict-overflow=5 -I../include -D_GNU_SOURCE 
-DNO_ANDROID_BACKEND   -c -o booleans.o booleans.c
booleans.c: In function ‘security_get_boolean_names’:
booleans.c:39:5: error: assuming signed overflow does not occur 
when changing X +- C1 cmp C2 to X cmp C2 -+ C1 
[-Werror=strict-overflow]
   39 | int security_get_boolean_names(char ***names, int *len)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors