Re: [PATCH] testsuite: analyzer: expect alignment warning with -fshort-enums

[Jeff Law <jeffreyalaw@gmail.com>]

On 11/19/23 00:36, Alexandre Oliva wrote:
> 
> On targets that have -fshort-enums enabled by default, the type casts
> in the pr108251 analyzer tests warn that the byte-aligned enums may
> not be sufficiently aligned to be a struct connection *.  The function
> can't know better, the warning is reasonable, the code doesn't
> expected enums to be shorter and less aligned than the struct.
> 
> Rather than use -fno-short-enums, I decided to embrace the warning on
> targets that have short_enums enabled by default.
> 
> However, C++ doesn't issue the warning, because even with
> -fshort-enums, enumeration types are not TYPE_PACKED, and the
> expression is not sufficiently simplified by the C++ front-end for
> check_and_warn_address_or_pointer_of_packed_member to identify the
> insufficiently aligned pointer.  So don't expect the warning there.
> 
> (I've got followup patches in testing to get the same warnings in C++)
> 
> Regstrapped on x86_64-linux-gnu, also tested on arm-eabi with default
> cpu on trunk, and with tms570 on gcc-13.  Ok to install?
> 
> 
> for  gcc/testsuite/ChangeLog
> 
> 	* c-c++-common/analyzer/null-deref-pr108251-smp_fetch_ssl_fc_has_early-O2.c:
> 	Expect "unaligned pointer value" warning on short_enums
> 	targets, but not in c++.
> 	* c-c++-common/analyzer/null-deref-pr108251-smp_fetch_ssl_fc_has_early.c:
> 	Likewise.
OK.  Hell of a filename for a single test :-)

jeff