[Bug c/91046] New: missing warning about empty translation unit

[vincent-gcc at vinc17 dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91046

            Bug ID: 91046
           Summary: missing warning about empty translation unit
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vincent-gcc at vinc17 dot net
  Target Milestone: ---

The C standard forbids empty translation units, and if the program is compiled
successfully (as what GCC does by default), the behavior of this program is
undefined (currently, even with GCC, as the behavior is not specified by its
manual). Thus GCC should issue a warning, even without -pedantic.

Alternatively, GCC could explicitly define the behavior as an extension (if
this is currently the case) and document it in its manual, in which case the
warning could be issued only with -pedantic as now. It should be sufficient to
say that empty translation units are allowed, since the text of the C standard
would not need additional specifications to make the behavior unambiguous.