https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100972
Bug ID: 100972 Summary: Missing error with "implicit none (external)" Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: gs...@t-online.de Target Milestone: --- In the following example function g has no known interface and is not declared external. implicit none (external) does not catch it. Affects versions down to at least r5. $ cat z1.f90 program p implicit none (external) real, external :: f real :: a, b a = f() b = g() end $ gfortran-12-20210606 -c z1.f90 $ BTW, ifort/ifx 2021.2 gets it right with error #8889: Explicit declaration of the EXTERNAL attribute is required. [G]