warning cleanup: GNU C++ initializer warnings.

This is the eight and final round of an effort to enable
GCC's -Wextra option. The C++ compiler, with -Wextra,
doesn't like C's universal struct initializer { 0 },
individually complaining about all the remaining members
not being initialized. What works in C++ is the { }
initializer. Conditional definition to the rescue.

* lib.h (all_zero_init): New macro which expands to
{ } under C++, and { 0 } under C.

* lib.c (make_time_impl, epoch_tm, time_string_meth,
time_parse_meth): Use all_zero_init.

* parser.c (prime_parser): Likewise.

* socket.c (sock_mark_connected): Likewise.

* sysif.c (fcntl_wrap): Likewise.

* termios.c (encode_speeds, decode_speeds): Likewise.

* configure (diag_flags): Add -Wextra.

1 files changed, 1 insertions, 1 deletions

diff --git a/configure b/configure
index 250cb772..a2000b51 100755
--- a/configure
+++ b/configure
@@ -134,7 +134,7 @@ yacc_is_newer_bison=
 nm='$(cross)$(tool_prefix)nm'
 opt_flags='-O2 -fno-stack-protector'
 lang_flags='-ansi -D_XOPEN_SOURCE=700 -D_POSIX_C_SOURCE=200112 -D_GNU_SOURCE'
-diag_flags='-Wall -Werror=implicit-function-declaration -Werror=missing-prototypes -Werror=strict-prototypes'
+diag_flags='-Wall -Wextra -Werror=implicit-function-declaration -Werror=missing-prototypes -Werror=strict-prototypes'
 debug_flags=-g
 debug_only_flags=-DTXR_DEBUG
 debug_also=