On 08/21/2018 09:57 AM, Martin Sebor wrote: > On 08/21/2018 02:59 AM, Richard Biener wrote: >> On Tue, 21 Aug 2018, Bernd Edlinger wrote: >> >>> gcc -S -O2 -Wall -Wformat-overflow -ftrack-macro-expansion=0 >>> -fshort-wchar builtin-sprintf-warn-20.c >>> builtin-sprintf-warn-20.c: In function 'test': >>> builtin-sprintf-warn-20.c:19:39: warning: hex escape sequence out of >>> range >>> 19 | ? (char*)L"\x4142\x4344" : (char*)L"\x41424344\x45464748"; >>> | ^~~~~~~~~~~~~~~~~~~~~~~ >>> >>> Hmm, this test might create some noise on short-wchar targets. >>> >>> I would prefer a warning here, about the wrong type of the parameter. >>> The buffer overflow is only a secondary thing. >>> >>> For constant objects like those, the GIMPLE type is still guaranteed >>> to be reliable, >>> right? >> >> TREE_TYPE of tcc_declaration and tcc_constant trees should more-or-less >> (minus qualifications not affecting semantics) be those set by >> frontends. > > A warning for these cases should be relatively straightforward > to add to the sprintf pass. It would require c_strlen() to return > the type of the string argument to the caller. That way sprintf's > format_string() function could compare the string type to the > expected type of the directive. Umm, why would c_strlen need to return that? We should be able to get to it directly from the argument?!? What am I missing here?
jeff
