On Tue, Nov 5, 2013 at 1:08 AM, Eric Blake <eblake@xxxxxxxxxx> wrote: > On 11/04/2013 03:49 AM, Ryota Ozaki wrote: >> This patch shuts up the following warning of clang: >> >> virsh.c:2761:22: error: assigning to 'char *' from 'const char [6]' discards qualifiers >> [-Werror,-Wincompatible-pointer-types-discards-qualifiers] >> rl_readline_name = "virsh"; >> ^ ~~~~~~~ > > Huh? <readline/readline.h> lists: > > /* The name of the calling program. You should initialize this to > whatever was in argv[0]. It is used when parsing conditionals. */ > extern const char *rl_readline_name; > > at least for readline-devel-6.2 on Fedora 19. Why is clang failing to > see that the assignment is to something already marked const? Is it a > bug in your readline header? Grrr. It seems that this is Mac OS X specific problem :-/ /usr/include/readline/readline.h of Mac OS X is still: extern char *rl_readline_name; The readline.h seems to be checked out from an old NetBSD and not updated for a long time. BTW recent *BSD seem to have migrated to the above const char * version. > >> >> Tested on Mac OS X 10.8.5 (clang-500.2.75) and >> Fedora 19 (gcc 4.8.1). >> >> Signed-off-by: Ryota Ozaki <ozaki.ryota@xxxxxxxxx> >> --- >> tools/virsh.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/virsh.c b/tools/virsh.c >> index 241c5b8..f45ee0a 100644 >> --- a/tools/virsh.c >> +++ b/tools/virsh.c >> @@ -2758,7 +2758,7 @@ vshReadlineInit(vshControl *ctl) >> const char *histsize_str; >> >> /* Allow conditional parsing of the ~/.inputrc file. */ >> - rl_readline_name = "virsh"; >> + rl_readline_name = (char *) "virsh"; > > On the surface, this seems okay, but I'd rather know WHY we need it, and > also add a comment that casting away const is due to whatever the root > cause is. So we need to write a comment about the Mac OS X's flaw. I'll send a revised patch later. Thanks, ozaki-r > > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org > -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list