https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91442
Bug ID: 91442 Summary: Wrong "may be used uninitialized" warning with allocation on assignment Product: gcc Version: 8.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: jellby at yahoo dot com Target Milestone: --- Simple test case: !======================= program test character(len=:), allocatable :: string string='Hello world!' write(6,*) string end program !======================= Compile with "-Wall": test.f90:3:0: string='' Warning: ‘.string’ may be used uninitialized in this function [-Wmaybe-uninitialized] Adding "-O1" removes the warning, though.