add address and undefined sanitizers to github action

[mo-xiaoming]

Besides being ugly, there are few things to note

1. Currently leak detection is disabled
2. Has to add something like -Og to debug flags, otherwise, get warning _FORTIFY_SOURCE requires compiling with optimization (-O). This is a long standing nix/gcc bug GCC has unwanted flags NixOS/nixpkgs#18995
3. Default added to path, otherwise, nix generates something like hobbesPackages/gcc-8/llvm-9//hobbes. Don't know how to get ride of //, so a Default added
4. Adding sanitizers make build slow, and Release build with sanitizer and debug symbols takes forever to build. So there is only one active(gcc8, llvm11?) version is checked by sanitizers

[mo-xiaoming]

It just proved its value, a null pointer reference was detected

/nix/store/rnh1x6pijwlmk14cy5jnyl5v51mc72wi-gcc-8.4.0/include/c++/8.4.0/bits/stl_iterator.h:797:17: runtime error: reference binding to null pointer of type 'const unsigned char'
    #0 0x952bef in __gnu_cxx::__normal_iterator<unsigned char const*, std::vector<unsigned char, std::allocator<unsigned char> > >::operator*() const /nix/store/rnh1x6pijwlmk14cy5jnyl5v51mc72wi-gcc-8.4.0/include/c++/8.4.0/bits/stl_iterator.h:797
    #1 0x952bef in void hobbes::fregion::writes<__gnu_cxx::__normal_iterator<unsigned char const*, std::vector<unsigned char, std::allocator<unsigned char> > > >(hobbes::fregion::imagefile*, __gnu_cxx::__normal_iterator<unsigned char const*, std::vector<unsigned char, std::allocator<unsigned char> > >, __gnu_cxx::__normal_iterator<unsigned char const*, std::vector<unsigned char, std::allocator<unsigned char> > >) ../include/hobbes/fregion.H:265
    #2 0x952bef in hobbes::fregion::write(hobbes::fregion::imagefile*, std::vector<unsigned char, std::allocator<unsigned char> > const&) ../include/hobbes/fregion.H:273
    #3 0x952bef in hobbes::fregion::addBinding(hobbes::fregion::imagefile*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::vector<unsigned char, std::allocator<unsigned char> > const&, unsigned long) ../include/hobbes/fregion.H:578
    #4 0x95a4f9 in hobbes::fregion::openFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool, unsigned short, unsigned short, unsigned long) ../include/hobbes/fregion.H:903
    #5 0x8e118f in hobbes::fregion::writer::writer(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ../include/hobbes/fregion.H:1945
    #6 0x8e118f in makeTestData(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ../test/Python.C:98
    #7 0x8e8c34 in test_Python_FRegion() ../test/Python.C:272
    #8 0x71650d in TestCoord::runTestGroups(Args const&) ../test/Main.C:64
    #9 0x7297f6 in main ../test/Main.C:143
    #10 0x7ffff6184dec in __libc_start_main (/nix/store/v8q6nxyppy1myi3rxni2080bv8s9jxiy-glibc-2.32-40/lib/libc.so.6+0x27dec)
    #11 0x4927d9 in _start (/build/source/build/hobbes-test+0x4927d9)

WIP

[smunix]

there's a debug flag to this nix expression, you should use that instead

[smunix]

Run sanitizers with clang only (not gcc)

[smunix]

• add new SAN specific package targets
• use Clang (not GCC) only for the SAN packages

[smunix]

Add new separate SAN specific packages withSans instead. Do not add params to the existing ones

[mo-xiaoming]

There are few changed in the last two commits

1. Previous crash was caused by accessing the first element of an empty vector

   hobbes/include/hobbes/fregion.H

   Line 903 in 30574be

   addBinding(f, ".za", bytes(), f->empty_array);

2. test/Python.C failed on my ubuntu20.04

       Python (1 test)
     ---------------------------------------------------------
   Traceback (most recent call last):
     File "/tmp/hdb-unittest-1.py", line 14, in <module>
       f = fregion.FRegion(sys.argv[1])
     File "/home/ubuntu/hobbes-llvm11/scripts/fregion.py", line 1068, in __init__
       bind.reader = makeReader({}, bind.ty)
     File "/home/ubuntu/hobbes-llvm11/scripts/fregion.py", line 1030, in makeReader
       return TyCase(readerDisp).apply(ty)
     File "/home/ubuntu/hobbes-llvm11/scripts/fregion.py", line 247, in apply
       return self.dtors["prim"](ty)
     File "/home/ubuntu/hobbes-llvm11/scripts/fregion.py", line 1019, in <lambda>
       "prim":    lambda p:  makePrimReader(renv, p),
     File "/home/ubuntu/hobbes-llvm11/scripts/fregion.py", line 958, in makePrimReader
       raise Exception("I don't know how to decode the primitive type: " + p.name)
   Exception: I don't know how to decode the primitive type: b'bool'
       FRegion FAIL (317.155ms)
   

   include(FindPythonInterp) finds python3 on my system, but fregion.py only can handle python2 strings (bytes by default), and python3 uses unicode as default, so we can see b'bool' doesn't match 'bool'

   Migrating this script to be python3 compatible is just too much work, so I just simply force it to search python2.7

3. enableDebugging doesn't seem to change CMAKE_BUILD_TYPE, it still use Release, which doesn't set proper flags

   diff --git a/nix/overlays.nix b/nix/overlays.nix
   index 14b1944..55f7636 100644
   --- a/nix/overlays.nix
   +++ b/nix/overlays.nix
   @@ -79,7 +79,6 @@ let
          inherit version src meta doCheck doTarget;
   
          dontStrip = true;
   -      cmakeBuildType="Debug";
          cmakeFlags = [
            "-DUSE_ASAN_AND_UBSAN:BOOL=ON"
          ];
   @@ -119,7 +118,7 @@ in {
          (llvmVersion: {
            name = "clang-" + toString llvmVersion + "-ASanAndUBSan";
            value = recurseIntoAttrs ({
   -          hobbes = dbg (callPackage withCLANGAsanAndUBSan { inherit llvmVersion; });
   +          hobbes = enableDebugging (callPackage withCLANGAsanAndUBSan { inherit llvmVersion; });
            });
          }) llvmVersions));
    }

Now CI failed on an function pointer conversion which I've seen at least a month ago, then I've not been able to reproduce it since then...

WIP

[smunix]

nice catch!

[smunix]

this is great, @mo-xiaoming