[Bug fortran/81758] [OOP] Broken vtab
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81758 --- Comment #6 from DIL --- It is not that I am not willing to, I just do not see an easy way to reduce the relevant code. For now, I have attached a debugger screenshot (jpg above) to show you the details of the problem. The segfault occurs when running the binary test_gfc.x produced by the Makefile, specifically in the GFC::graph test (gfc_graph.F90). In the bottom left corner of the .JPG file you will see the exact callstack at the point of crash. In the central window, you will see the line 742 of gfc_vector.F90, specifically: val_p => cep%get_value(errc) The pointer "cep" is class(gfc_cont_elem_t) defined in gfc_base.F90. Now if you look at the right window on the .JPG where I inspect the content of the "cep", you will see a completely messed up _vptr table, where the type-bound procedure bindings are associated with wrong procedures from a completely unrelated type "vector_t" from gfc_vector.F90. In particular, if you look at the "get_value" binding, that is, the procedure we are trying to call in line 742 above, you will see that it is wrongly associated with vector_t%vectorlowerbound, a totally unrelated type-bound procedure from a different type. That's exactly why the segfault occurs (please see the callstack). All other type-bound bindings of "cep" are wrong as well, except maybe few.
[Bug fortran/81758] [OOP] Broken vtab
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81758 --- Comment #7 from DIL --- P.S. I do not have GCC-8.0 installed anywhere.
[Bug fortran/81758] [OOP] Broken vtab
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81758 --- Comment #5 from DIL --- Created attachment 42373 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42373=edit Debugger screenshot
[Bug fortran/81758] [OOP] Broken vtab
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81758 --- Comment #4 from Dominique d'Humieres --- Do you have access to a recent revision of trunk (8.0)? If yes, do you still see the problem? I understand that you are not willing to reduce your code. If yes, I have managed to compile gfc_vector.F90, could you provide at least a driver showing the problem?
[Bug fortran/81758] [OOP] Broken vtab
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81758 Thomas Koenig changed: What|Removed |Added Blocks||81748 --- Comment #3 from Thomas Koenig --- Could be a dup of 81748. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81748 [Bug 81748] extensible types non-conforming behaviour
[Bug fortran/81758] [OOP] Broken vtab
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81758 --- Comment #2 from DIL --- No, at this point I do not, unfortunately. These OOP bugs tend to show up at higher levels, so it is not always clear how to reduce it to something small. I will try to reduce it to something smaller, but not sure how far. For example, the current problem shows up in the implementation of a vector container (gfc_vector.F90), but only when it is used to implement something more complex, specifically the graph container in this case (gfc_graph.F90). The latter uses three containers in its implementation: vector, list, and dictionary, so it depends on all of those.
[Bug fortran/81758] [OOP] Broken vtab
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81758 Thomas Koenig changed: What|Removed |Added Status|UNCONFIRMED |WAITING Last reconfirmed||2017-08-07 CC||tkoenig at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #1 from Thomas Koenig --- Do you have a reduced test case that does not require understanding your whole package?
