On Thu, Apr 4, 2019 at 2:13 PM Martin Liška <mli...@suse.cz> wrote: > On 4/3/19 6:31 PM, Martin Jambor wrote: > > Hello Shubham, > > > > On Fri, Mar 29 2019, Shubham Narlawar wrote: > >> Hi, here is my proposal for the above idea. Please review and suggest > >> necessary changes. > >> > >> > https://docs.google.com/document/d/11MNhuuD7dbwAfSW6ZgFrAys9My1Lw1PuMVcAqeNGr7A/edit?usp=sharing > > > > I have had a quick look and the proposal seems very nice. > > > > How did you select the attributes you want to implement in csmith? It > > is for example a little strange that you decided to include "pure" but > > not "const." If you handle visibility, you might as well consider > > throwing in externally_visible too, I guess. As a stretch goal, the > > alias function attribute might be useful to exercise nasty paths in GCC > > IPA optimizations. > > > > I assume Andi Kleen has seen this proposal and if he is fine with it, so > > am I. > > > > Thanks, > > > > Martin > > > > Hi. > > Just for the record, Martin Jambor asked me to co-mentor during time period > when Andi will be on vacation (if I'm correct). >
I have included your name as co-mentor in my proposal. Is it fine? > I have couple of questions/ideas about the proposal: > > 1) I would not spend much time with nested functions, it's quite legacy > C extension > Once Andi Kleen suggested that nested functions has lot of potential for bugs. I will not only just add nested functions but I plan to do integration testing along with merging of previously implemented extensions in phase 3 of gsoc timeline > 2) for functions, I would basically include add potential attribute: > > https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#Common-Function-Attributes > > see: > gcc/c-family/c-attribs.c:242 > const struct attribute_spec c_common_attribute_table[] = > ... > > I assume potential attributes means attributes that will trigger different components of GCC. Can you point out such potential attributes such as alias. > > 3) similarly for variables: > > https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#Common-Variable-Attributes Few of variables attributes like packed, unused, section, aligned are already implemented in Csmith. > > 4) and similarly for types > > https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#Common-Type-Attribute > <https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#Common-Type-Attributes> 5) One big question about csmith I have. It's quite easy to come up with a > test-case which > causes an ICE. But it's more difficult to come up with a test-case that is > miscompiled > by a compiler. It's mainly due to an invalid behavior in the generated > test-case. > One can theoretically catch that with sanitizers (ASAN, UBSAN, ...). But > still, it's > not easy. Are you considering catching wrong-code issue? > I use option -fsanitize=undefined and valgrind to check undefined behaviour. Are there any other ways to check it rather than sanitizers? Thanks, Shubham > > Thanks, > Martin >
