https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64861
Bug ID: 64861
Summary: Possible wrong code with BIND(C) and PRIVATE +
slightly bogus warning
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Keywords: diagnostic, wrong-code
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: burnus at gcc dot gnu.org
Blocks: 49111
This PR is partially identical to PR49111 / See also
https://groups.google.com/forum/#!topic/comp.lang.fortran/RedeUCqh12c ("Private
interfaces with iso_c_binding")
In modules, gfortran warns for module procedures - and for interface procedures
with BIND(C) attribute, which are marked as PRIVATE:
Warning: Symbol 'my_c_routine' at (1) is marked PRIVATE but has been given
the binding label 'my_c_routine'
This warning seems to be on by default (not checked) and is slightly bogus.
There are two meanings of PRIVATE: (a) avoid cluttering the name space when
USE-ing a module. (b) To hide a symbol from the rest of the world.
Fortran's meaning is (a), although some users think of (b) - seemingly also the
warning writer.
Additionally, there might be a wrong-code issue: gfortran marks PRIVATE module
procedures (and variables) which are not otherwise used as being only used in
that file - based on the knowledge that it cannot be used (without knowledge of
the name mangling of gfortran).
I think it currently misses the check for BIND(C). (BTW: A BIND(C) function
without a name (i.e. name="" or an internal procedure) can continue to be
marked as static.)
THUS:
* Check whether the TREE_PUBLIC handling is correctly done for BIND(C)+PRIVATE
(honoring additionally whether it has a binding name or not.)
The following items are the same/similar to PR49111
* Check whether the warning message makes really sense - and if so, improve the
wording and consider not to enable it by default.
* If continuing to warn: Consider not to warn at all for INTERFACE and only for
module procedures.
