Re: C++: is there a good way to check for a valid no-op conversion?
On 10/17/18, Martin Sebor wrote: > On 10/16/2018 02:06 PM, David Malcolm wrote: >> I've been extending -fopt-info to cover inlining, and I added a %S >> format code to dump_printf which accepts a symtab_node *. >> >> Unfortunately, -Wformat doesn't like the fact that I'm passing in a >> subclass pointer (cgraph_node *), e.g.: >> >> ipa-inline.c: In function ‘unsigned int early_inliner(function*)’: >> ipa-inline.c:2769:21: error: format ‘%S’ expects argument of type >> ‘symtab_node*’, >> but argument 3 has type ‘cgraph_node*’ [-Werror=format=] >> 2769 |"Flattening %S\n", node); >> |~^ >> | | | >> | | cgraph_node* >> | symtab_node* >> >> I could fix this by changing my format converter so that explicitly >> takes a cgraph_node *, but I wondered if it would be better to instead >> teach -Wformat to accept non-virtual subclass pointers, so that %S can >> handle symtab_node * and its two subclasses. > > It would have helped in the gcall* vs gimple* case as well. It > would be nice to teach -Wformat about these conversions in general. > (on a somewhat related note, other than pedantic conformance, I > don't think there is value in -Wformat complaining about %p with > non-void* object pointer arguments either). That sounds like something worth splitting out once there's a separate -Wformat-pedantic flag as per bug 67479: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67479 > > Martin > >> >> Does this sound sane, and is there a conversion function I can call for >> this case? cp_convert_to_pointer seemed the closest match. >> >> Thanks >> Dave >> >
Re: C++: is there a good way to check for a valid no-op conversion?
On 10/16/2018 02:06 PM, David Malcolm wrote: I've been extending -fopt-info to cover inlining, and I added a %S format code to dump_printf which accepts a symtab_node *. Unfortunately, -Wformat doesn't like the fact that I'm passing in a subclass pointer (cgraph_node *), e.g.: ipa-inline.c: In function ‘unsigned int early_inliner(function*)’: ipa-inline.c:2769:21: error: format ‘%S’ expects argument of type ‘symtab_node*’, but argument 3 has type ‘cgraph_node*’ [-Werror=format=] 2769 |"Flattening %S\n", node); |~^ | | | | | cgraph_node* | symtab_node* I could fix this by changing my format converter so that explicitly takes a cgraph_node *, but I wondered if it would be better to instead teach -Wformat to accept non-virtual subclass pointers, so that %S can handle symtab_node * and its two subclasses. It would have helped in the gcall* vs gimple* case as well. It would be nice to teach -Wformat about these conversions in general. (on a somewhat related note, other than pedantic conformance, I don't think there is value in -Wformat complaining about %p with non-void* object pointer arguments either). Martin Does this sound sane, and is there a conversion function I can call for this case? cp_convert_to_pointer seemed the closest match. Thanks Dave
C++: is there a good way to check for a valid no-op conversion?
I've been extending -fopt-info to cover inlining, and I added a %S format code to dump_printf which accepts a symtab_node *. Unfortunately, -Wformat doesn't like the fact that I'm passing in a subclass pointer (cgraph_node *), e.g.: ipa-inline.c: In function ‘unsigned int early_inliner(function*)’: ipa-inline.c:2769:21: error: format ‘%S’ expects argument of type ‘symtab_node*’, but argument 3 has type ‘cgraph_node*’ [-Werror=format=] 2769 |"Flattening %S\n", node); |~^ | | | | | cgraph_node* | symtab_node* I could fix this by changing my format converter so that explicitly takes a cgraph_node *, but I wondered if it would be better to instead teach -Wformat to accept non-virtual subclass pointers, so that %S can handle symtab_node * and its two subclasses. Does this sound sane, and is there a conversion function I can call for this case? cp_convert_to_pointer seemed the closest match. Thanks Dave
