https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108906
--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Tobias Burnus <bur...@gcc.gnu.org>: https://gcc.gnu.org/g:d3e427f684b0cd7cedbe7b93a06f455e562c5901 commit r13-6341-gd3e427f684b0cd7cedbe7b93a06f455e562c5901 Author: Tobias Burnus <tob...@codesourcery.com> Date: Sat Feb 25 11:55:08 2023 +0100 Fortran: Skip bound conv in gfc_conv_gfc_desc_to_cfi_desc with intent(out) ptr [PR108621] When the dummy argument of the bind(C) proc is 'pointer, intent(out)', the conversion of the GFC to the CFI bounds can be skipped: it is not needed and avoids issues with noninit memory. Note that the 'cfi->base_addr = gfc->addr' assignment is kept as the C code of a user might assume that a nullified pointer arrives as NULL (or even a specific value). For instance, gfortran.dg/c-interop/section-{1,2}.f90 assumes the value NULL. Note 2: The PR is about a may-be-uninitialized warning with intent(out). In the PR's testcase, the pointer was nullified and should not have produced that warning. That is a diagnostic issue, now tracked as PR middle-end/108906 as the issue in principle still exists (e.g. with 'intent(inout)'). [But no longer for intent(out).] Note 3: With undefined pointers and no 'intent', accessing uninit memory is unavoidable on the caller side as the compiler cannot know what the C function does (but this usage determines whether the pointer is permitted be undefined or whether the bounds must be gfc-to-cfi converted). gcc/fortran/ChangeLog: PR fortran/108621 * trans-expr.cc (gfc_conv_gfc_desc_to_cfi_desc): Skip setting of bounds of CFI desc for 'pointer,intent(out)'. gcc/testsuite/ChangeLog: PR fortran/108621 * gfortran.dg/c-interop/fc-descriptor-pr108621.f90: New test.
