Segfault in souffleprof

[langston-barrett]

souffle --version
Souffle: 2.2-129-gfce85d9ec(32bit Domains)
Copyright (c) 2016-19 The Souffle Developers.
Copyright (c) 2013-16 Oracle and/or its affiliates.

GDB backtrace:

#0  souffle::profile::Reader::processFile (this=0xe4e088) at ../src/include/souffle/profile/Reader.h:343
#1  0x000000000024b6a9 in souffle::profile::Tui::updateDB (this=0x7ffcca36c9e8)
    at ../src/include/souffle/profile/Tui.h:1468
#2  0x00000000002495bf in souffle::profile::Tui::Tui (this=0x7ffcca36c9e8, filename=..., live=<optimized out>)
    at ../src/include/souffle/profile/Tui.h:95
#3  0x00000000002393fa in souffle::profile::Cli::parse (this=0x7ffcca36cbc8) at ../src/include/souffle/profile/Cli.h:89
#4  0x0000000000232d9f in main (argc=<optimized out>, argv=<optimized out>) at ../src/souffle_prof.cpp:23

prof.json.zip

[langston-barrett]

ASan gives a bit more detail:

AddressSanitizer:DEADLYSIGNAL
=================================================================
==2475==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000088 (pc 0x000000409c3b bp 0x7ffd98ebd550 sp 0x7ffd98ebd530 T0)
==2475==The signal is caused by a READ memory access.
==2475==Hint: address points to the zero page.
    #0 0x409c3b in souffle::profile::Relation::addReads(unsigned long) /mate/souffle/build/../src/include/souffle/profile/Relation.h:249:26
    #1 0x400a74 in souffle::profile::Reader::processFile() /mate/souffle/build/../src/include/souffle/profile/Reader.h:343:52
    #2 0x3d3cf7 in souffle::profile::Tui::updateDB() /mate/souffle/build/../src/include/souffle/profile/Tui.h:1468:17
    #3 0x3cfba2 in souffle::profile::Tui::Tui(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, bool, bool) /mate/souffle/build/../src/include/souffle/profile/Tui.h:95:9
    #4 0x38a3ca in souffle::profile::Cli::parse() /mate/souffle/build/../src/include/souffle/profile/Cli.h:89:13
    #5 0x374035 in main /mate/souffle/build/../src/souffle_prof.cpp:23:13
    #6 0x7f3856ecd0b2 in __libc_start_main /build/glibc-eX1tMB/glibc-2.31/csu/../csu/libc-start.c:308:16
    #7 0x2c96dd in _start (/mate/souffle/build-asan/src/souffleprof+0x2c96dd)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /mate/souffle/build/../src/include/souffle/profile/Relation.h:249:26 in souffle::profile::Relation::addReads(unsigned long)
==2475==ABORTING

[langston-barrett]

With this diff:

diff --git a/src/include/souffle/profile/Reader.h b/src/include/souffle/profile/Reader.h
index 1e93980c5..7df098035 100644
--- a/src/include/souffle/profile/Reader.h
+++ b/src/include/souffle/profile/Reader.h
@@ -329,6 +329,9 @@ public:
             for (const auto& rule : relation.second->getRuleMap()) {
                 for (const auto& atom : rule.second->getAtoms()) {
                     std::string relationName = extractRelationNameFromAtom(atom);
+                    std::cout << "NAME " << relationName << std::endl;
+                    std::cout << "ATOM " << atom.identifier << std::endl;
+                    std::cout << "REL " << relationMap[relationName] << std::endl;
                     relationMap[relationName]->addReads(atom.frequency);
                 }
             }
@@ -340,6 +343,9 @@ public:
                             relationName = relationName.substr(7);
                         }
                         assert(relationMap.count(relationName) > 0 || "Relation name for atom not found");
+                        std::cout << "NAME " << relationName << std::endl;
+                        std::cout << "ATOM " << atom.identifier << std::endl;
+                        std::cout << "REL " << relationMap[relationName] << std::endl;
                         relationMap[relationName]->addReads(atom.frequency);
                     }
                 }

I see:

NAME @new_unification.unify_repr_aux
ATOM @new_unification.unify_repr_aux
REL (nil)
Segmentation fault (core dumped)

There's some subsumption going on in my source program for unify_repr_aux, so I suspect this has something to do with that.

[b-scholz]

We have not tested the profile for subsumption.

[b-scholz]

Can you produce a small test-case?