https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86120
Bug ID: 86120 Summary: SIGSEGV without backtrace when using submodules Product: gcc Version: 7.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: simon.kluepfel at gmail dot com Target Milestone: --- Created attachment 44264 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44264&action=edit source code The attached code does not run as expected when compiling with -O3 using gfortran 6 and 7. For gfortran-6 a write statement to a file inside the routine "fixes" the segfault. Works for gfortran-8. Moving the submodule into the module, or not using the str_set routine avoids the segfault as well. compiled with: gfortran-XXX -O3 -std=f2008 -g -fbacktrace -fcheck=all string.f03 dt.f03 dt_sub.f03 main.f03 for XXX= gcc version 6.4.0 20180424 (Debian 6.4.0-17) gcc version 7.3.0 (Debian 7.3.0-21) gcc version 8.1.0 (Debian 8.1.0-5) output expected / v. 8: $ ./a.out 1 2 1 2 1 2 $ v. 7: $ ./a.out 1 2 1 2 Program received signal SIGSEGV: Segmentation fault - invalid memory reference. Backtrace for this error: #0 0x7f8c0df6e0fd in ??? #1 0x7f8c0df6d343 in ??? #2 0x7f8c0d3e2eff in ??? #3 0x0 in ??? Segmentation fault v. 6: $ ./a.out 1 2 Program received signal SIGSEGV: Segmentation fault - invalid memory reference. Backtrace for this error: #0 0x7f1cbf72dced in ??? #1 0x7f1cbf72cf4d in ??? #2 0x7f1cbeba1eff in ??? #3 0x0 in ??? Segmentation fault