Build warnings

[evoskuil]

https://travis-ci.org/github/libbitcoin/libbitcoin-system/jobs/760927790#L2485

********************** Download libbitcoin/secp256k1/version6 **********************
Cloning into 'secp256k1'...
remote: Enumerating objects: 184, done.
remote: Counting objects: 100% (184/184), done.
remote: Compressing objects: 100% (138/138), done.
remote: Total 184 (delta 51), reused 99 (delta 39), pack-reused 0
Receiving objects: 100% (184/184), 215.36 KiB | 3.03 MiB/s, done.
Resolving deltas: 100% (51/51), done.
libtoolize: putting auxiliary files in AC_CONFIG_AUX_DIR, 'build-aux'.
libtoolize: copying file 'build-aux/ltmain.sh'
libtoolize: putting macros in AC_CONFIG_MACRO_DIRS, 'build-aux/m4'.
libtoolize: copying file 'build-aux/m4/libtool.m4'
libtoolize: copying file 'build-aux/m4/ltoptions.m4'
libtoolize: copying file 'build-aux/m4/ltsugar.m4'
libtoolize: copying file 'build-aux/m4/ltversion.m4'
libtoolize: copying file 'build-aux/m4/lt~obsolete.m4'
configure.ac:10: installing 'build-aux/compile'
configure.ac:5: installing 'build-aux/config.guess'
configure.ac:5: installing 'build-aux/config.sub'
configure.ac:9: installing 'build-aux/install-sh'
configure.ac:9: installing 'build-aux/missing'
Makefile.am: installing 'build-aux/depcomp'
parallel-tests: installing 'build-aux/test-driver'
configure options:
--disable-tests
--enable-module-recovery
--enable-endomorphism
--enable-isystem
--with-icu
--with-png
--with-qrencode
--disable-shared
--prefix=/home/travis/build/libbitcoin/libbitcoin-system/my-prefix
CFLAGS=-Os
CXXFLAGS=-Os
--enable-static
configure: WARNING: you should use --build, --host, --target
configure: WARNING: you should use --build, --host, --target
configure: WARNING: you should use --build, --host, --target
configure: WARNING: you should use --build, --host, --target
configure: WARNING: you should use --build, --host, --target
configure: WARNING: unrecognized options: --enable-isystem, --with-icu, --with-png, --with-qrencode
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking how to print strings... printf
checking for style of include used by make... GNU
checking for gcc... clang-5.0
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether clang-5.0 accepts -g... yes
checking for clang-5.0 option to accept ISO C89... none needed
checking whether clang-5.0 understands -c and -o together... yes
checking dependency style of clang-5.0... gcc3
checking for a sed that does not truncate output... /bin/sed
checking for grep that handles long lines and -e... /bin/grep
checking for egrep... /bin/grep -E
checking for fgrep... /bin/grep -F
checking for ld used by clang-5.0... /usr/bin/ld
checking if the linker (/usr/bin/ld) is GNU ld... yes
checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B
checking the name lister (/usr/bin/nm -B) interface... BSD nm
checking whether ln -s works... yes
checking the maximum length of command line arguments... 1572864
checking how to convert x86_64-pc-linux-gnu file names to x86_64-pc-linux-gnu format... func_convert_file_noop
checking how to convert x86_64-pc-linux-gnu file names to toolchain format... func_convert_file_noop
checking for /usr/bin/ld option to reload object files... -r
checking for objdump... objdump
checking how to recognize dependent libraries... pass_all
checking for dlltool... no
checking how to associate runtime and link libraries... printf %s\n
checking for ar... ar
checking for archiver @FILE support... @
checking for strip... strip
checking for ranlib... ranlib
checking command to parse /usr/bin/nm -B output from clang-5.0 object... ok
checking for sysroot... no
checking for a working dd... /bin/dd
checking how to truncate binary pipes... /bin/dd bs=4096 count=1
checking for mt... mt
checking if mt is a manifest tool... no
checking how to run the C preprocessor... clang-5.0 -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking for dlfcn.h... yes
checking for objdir... .libs
checking if clang-5.0 supports -fno-rtti -fno-exceptions... yes
checking for clang-5.0 option to produce PIC... -fPIC -DPIC
checking if clang-5.0 PIC flag -fPIC -DPIC works... yes
checking if clang-5.0 static flag -static works... yes
checking if clang-5.0 supports -c -o file.o... yes
checking if clang-5.0 supports -c -o file.o... (cached) yes
checking whether the clang-5.0 linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes
checking dynamic linker characteristics... GNU/Linux ld.so
checking how to hardcode library paths into programs... immediate
checking whether stripping libraries is possible... yes
checking if libtool supports shared libraries... yes
checking whether to build shared libraries... no
checking whether to build static libraries... yes
checking whether make supports nested variables... (cached) yes
checking for pkg-config... /usr/bin/pkg-config
checking pkg-config is at least version 0.9.0... yes
checking for ar... /usr/bin/ar
checking for ranlib... /usr/bin/ranlib
checking for strip... /usr/bin/strip
checking for gcc... clang
checking whether we are using the GNU C compiler... (cached) yes
checking whether clang accepts -g... yes
checking for clang option to accept ISO C89... (cached) none needed
checking whether clang understands -c and -o together... (cached) yes
checking dependency style of clang... (cached) gcc3
checking how to run the C preprocessor... clang -E
checking for clang-5.0 option to accept ISO C89... (cached) none needed
checking dependency style of clang-5.0... gcc3
checking if clang-5.0 supports -std=c89 -pedantic -Wall -Wextra -Wcast-align -Wnested-externs -Wshadow -Wstrict-prototypes -Wno-unused-function -Wno-long-long -Wno-overlength-strings... yes
checking if clang-5.0 supports -fvisibility=hidden... yes
checking for __int128... yes
checking if native clang supports -Wall -Wextra -Wno-unused-function... yes
checking for working native compiler: clang... yes
checking for x86_64 assembly availability... yes
checking gmp.h usability... yes
checking gmp.h presence... yes
checking for gmp.h... yes
checking for __gmpz_init in -lgmp... yes
checking whether byte ordering is bigendian... no
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating Makefile
config.status: creating libsecp256k1.pc
config.status: creating src/libsecp256k1-config.h
config.status: executing depfiles commands
config.status: executing libtool commands
configure: WARNING: unrecognized options: --enable-isystem, --with-icu, --with-png, --with-qrencode
Build Options:
  with endomorphism       = yes
  with ecmult precomp     = yes
  with external callbacks = no
  with jni                = no
  with benchmarks         = yes
  with coverage           = no
  module ecdh             = no
  module recovery         = yes
  asm                     = x86_64
  bignum                  = gmp
  field                   = 64bit
  scalar                  = 64bit
  ecmult window size      = 15
  ecmult gen prec. bits   = 4
  CC                      = clang-5.0
  CFLAGS                  = -Os -W -std=c89 -pedantic -Wall -Wextra -Wcast-align -Wnested-externs -Wshadow -Wstrict-prototypes -Wno-unused-function -Wno-long-long -Wno-overlength-strings -fvisibility=hidden -O3
  CPPFLAGS                = 
  LDFLAGS                 = 
  CC       src/bench_verify.o
  CC       src/bench_sign.o
  CC       src/exhaustive_tests-tests_exhaustive.o
  CC       src/bench_recover.o
In file included from src/tests_exhaustive.c:26:
./src/secp256k1.c:72:9: warning: missing field 'pre_g_128' initializer
      [-Wmissing-field-initializers]
    { 0 },
        ^
./src/secp256k1.c:73:9: warning: missing field 'blind' initializer
      [-Wmissing-field-initializers]
    { 0 },
        ^
clang -I. -I./src -g -O2 -Wall -Wextra -Wno-unused-function -c src/gen_context.c -o gen_context.o
clang -g -O2 -Wall -Wextra -Wno-unused-function  gen_context.o -o gen_context
./gen_context
  CC       src/libsecp256k1_la-secp256k1.lo
src/secp256k1.c:72:9: warning: missing field 'pre_g_128' initializer
      [-Wmissing-field-initializers]
    { 0 },
        ^
src/secp256k1.c:73:9: warning: missing field 'blind' initializer
      [-Wmissing-field-initializers]
    { 0 },
        ^
2 warnings generated.
  CC       src/bench_internal-bench_internal.o
In file included from src/bench_internal.c:19:
./src/secp256k1.c:72:9: warning: missing field 'pre_g_128' initializer
      [-Wmissing-field-initializers]
    { 0 },
        ^
./src/secp256k1.c:73:9: warning: missing field 'blind' initializer
      [-Wmissing-field-initializers]
    { 0 },
        ^
2 warnings generated.
  CC       src/bench_ecmult-bench_ecmult.o
In file included from src/bench_ecmult.c:18:
./src/secp256k1.c:72:9: warning: missing field 'pre_g_128' initializer
      [-Wmissing-field-initializers]
    { 0 },
        ^
./src/secp256k1.c:73:9: warning: missing field 'blind' initializer
      [-Wmissing-field-initializers]
    { 0 },
        ^
2 warnings generated.
  CCLD     exhaustive_tests
  CCLD     libsecp256k1.la
/usr/bin/ar: `u' modifier ignored since `D' is the default (see `U')
  CCLD     bench_internal
  CCLD     bench_recover
  CCLD     bench_verify
  CCLD     bench_sign
2 warnings generated.
  CCLD     bench_ecmult
...