On Wed, 2022-06-01 at 14:50 -0400, David Malcolm wrote: > On Wed, 2022-06-01 at 23:22 +0530, Mir Immad wrote: > > HI everyone, > > > > I'm Immad Mir -- one of the GSoC students this year. I'll be working > > on > > adding static analysis support for POSIX file description APIs this > > summer. > > Welcome Immad - I'm looking forward to helping you on this project. > > For reference, I think you posted an initial prototype of this work > earlier this year here: > https://gcc.gnu.org/pipermail/gcc/2022-January/238192.html > https://gcc.gnu.org/pipermail/gcc/2022-February/238215.html > > > > > The plan is to let the static analyzer know about the FD APIs through > > the > > use of function attributes, although initially we might hardcode the > > logic > > to get started working. I'm looking for the suggestions on this from > > the > > people who have experience working with file-descriptors. > > We talked about this off-list; I think next steps could be: > > (1) get your initial prototype working again, hardcoding the names of > the functions for simplicity at first > > (2) find a list of system calls (e.g. those implemented on Linux), and > see which ones relate to file descriptors e.g. acquiring them, using > them, releasing them, and duplicating them. Look for patterns of usage > that could be expressed using function attributes. Probably ignore > "ioctl" for now. > > (3) probably talk to glibc's developers about this, since glibc > provides headers that wrap system calls, which would want to use the > attributes if we provide them > > (4) implement the attributes, so that the analyzer doesn't have > hardcoded function names, and can instead rely on function attributes. > GCC's attributes are implemented in gcc/c-family/c-attribs.cc; see the > big c_common_attribute_table array, which associates the string names > of the attrbutes with properties, including a handler callback. These > either set flags of a decl, or the attribute itself is appended to a > singly-linked list on that decl (for those things that don't directly > relate to fields of a decl). > > I believe Siddhesh Poyarekar has been looking at attributes from the > glibc side of things, so I'm CCing him in case he has input on this. > > I'm wondering if other people on this list have ideas for projects that > make heavy use of syscalls/file-descriptors that would benefit from > having this analyzer feature. Maybe systemd? > > Welcome again; hope this makes sense and is helpful > Dave
I've gone ahead and filed an RFE bug in our bugzilla to help track this work: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106003 Immad: you should probably assign that bug to yourself. Do you have an account yet for bugzilla? See: https://gcc.gnu.org/gitwrite.html#authenticated for info on how to get an account on sourceware.org/gcc.gnu.org I can be your sponsor. Once you have that, I think you automatically get a usern...@gcc.gnu.org account that you can use to login to the GCC bugzilla. Dave
