ares__iface_ip_flags_t cannot have the value 0.

[dzalyalov88]

0 is not a possible value for ares__iface_ip_flags_t, but in several places, it takes this value:

1. return 0; (ares__iface_ips.c:257)
2. ares__iface_ip_flags_t addrflag = 0; (ares__iface_ips.c:355)
3. ares__iface_ip_flags_t addrflag = 0; (ares__iface_ips.c:450)

[bradh352]

Is this actually emitting some warning somewhere ? This is valid in C to use an enum as a flags value, however C++ doesn't allow this. Are you trying to compile c-ares as C++ code?

[dzalyalov88]

yes, this warning caused a compilation issue:
"error: integer constant not in range of enumerated type 'ares__iface_ip_flags_t' [-Werror,-Wassign-enum]"

[dzalyalov88]

Before the last changes, c-ares was C++ compatible. And I hope it will be the same in the future.

[bradh352]

I'm not sure I understand why you'd compile C code with a C++ compiler, can you provide the reason why this is desirable? Is this some limitation of some embedded environment? Or are you just compiling with a warning flag to force this behavior?

[bradh352]

Looking at it -Wassign-enum only talks about integer constants, so if we define a NONE value of 0 for the flags, the issue would go away, it doesn't look like it warns on combining enum values as flags according to the docs. If that's the case and you're not actually using a C++ compiler to compile C code, then that would fix it rather than using a different type.

[bradh352]

Just tested it, it does warn when you combine 2 enum values as flags:

[74/92] Building C object src/lib/CMakeFiles/c-ares.dir/ares_strsplit.c.o
/Users/bhouse/svn/c-ares/src/lib/ares_strsplit.c:97:34: warning: integer constant not in range of enumerated type 'ares__buf_split_t' [-Wassign-enum]
    ARES_BUF_SPLIT_NO_DUPLICATES | ARES_BUF_SPLIT_CASE_INSENSITIVE, &llist);

[dzalyalov88]

I have checked our code.
We are using the clang compiler with the parameters -Wassign-enum and -Werror

[bradh352]

Can this warning flag be excluded, or at least be excluded from -Werror in your project? That's a non-standard flag.