On 5/13/26 9:29 AM, Thomas Koenig wrote:
Hello world,
the patch below is regression-tested. OK for trunk?
Best regards
Thomas
PR fortran/125092 - checks for binding label argument mismatch.
This patch implements some checks on different interfaces to the same
C binding functions. It contains a few policy changes, and is somewhat
more permissive than the standard, but there are no constraint
violations (to my knowledge) that it misses.
Apart from checking for standards conformance, this should also
help proof code against (now or future) type-based aliasing mishaps.
Checks for global identifiers are performed on a case-insensitive
basis by default, and only sensitive when -pedantic is in force.
This makes sense if Fortran code wants to interface to "FOO" and
"foo". The restriction to case-insensitive labels comes from a time
when relevant systems had linkers which were case-insensitive, and
it is not possible to implement C (especially the C versions referenced
in the standard) with such a linker.
Return types of functions, ranks, number, type and rank of arguments
are checked. In non-pedantic mode, arguments which have the same
prototype on the C side are permitted, for example passing a scalar
or an array by reference, or arrays of different rank (both for pass
by reference and pass by descriptors). Assumed types are also
assumed to bee OK. This functionality was checked in a few test
cases, so it would make little sense to remove it.
C_PTR is *not* compatible with a random argument passed by reference.
For example, a TYPE(C_PTR), VALUE argument is not compatible
with an INTEGER argument (without VALUE); C_LOC has to be used.
The one-liner in decl.cc may fix some ENTRY problems, I didn't check.
gcc/fortran/ChangeLog:
* decl.cc (add_global_entry): Use string from the heap instead
of a pointer to stack-allocated memory.
* frontend-passes.cc (check_against_globals): If there is an error
already, return early.
* gfortran.h (gfc_symbol_rank): New prototype.
* interface.cc (symbol_rank): Rename to
(gfc_symbol_rank): this.
(gfc_check_dummy_characteristics): Use new function name.
(gfc_check_result_characteristics): Likewise.
(gfc_compare_interfaces): Likewise.
(compare_parameter): Likewise.
(get_sym_storage_size): Likewise.
(gfc_procedure_use): Likewise.
* resolve.cc (decays_to_pointer): New function.
(c_types_conform): New function.
(compare_c_binding_arglists): New function.
(gfc_verify_binding_labels): Check return types and rank
plus argument lists if there is a pre-exisiting global
symbol.
gcc/testsuite/ChangeLog:
* gfortran.dg/PR100906.f90: Add -Wno-pedantic to options.
* gfortran.dg/PR100911.f90: Likewise.
* gfortran.dg/PR100915.f90: Likewise.
* gfortran.dg/PR94327.f90: Likewise.
* gfortran.dg/PR94331.f90: Likewise.
* gfortran.dg/bind_c_procs_4.f90: Add error messages, remove
warning.
* gfortran.dg/binding_label_tests_25.f90: Add error messages.
* gfortran.dg/binding_label_tests_3.f03: Add error messages.
* gfortran.dg/binding_label_tests_34.f90: Add -Wno-pedantic to
options.
* gfortran.dg/c_char_tests_4.f90: Likewise.
* gfortran.dg/c_char_tests_5.f90: Likewise.
* gfortran.dg/binding_label_tests_36.f90: New test.
* gfortran.dg/binding_label_tests_37.f90: New test.
Looks good to go. I wondered about the TO DO in one of the comments. Are you
planning to do this later? Any thoughts about it?
Thanks for the work,
Jerry
