I forgot to handle len=<nonconst> correctly. This patch does the same as for non-BIND(C). In the latter case, the call is:
gfc_generate_function_code → gfc_trans_deferred_vars → gfc_trans_deferred_array and that function has if (sym->ts.type == BT_CHARACTER && !INTEGER_CST_P (sym->ts.u.cl->backend_decl)) { gfc_conv_string_length (sym->ts.u.cl, NULL, &init); gfc_trans_vla_type_sizes (sym, &init); } Expect a déjà vu if you read the attached patch ... Thanks to Dominique for testing with -flto and finding this issue and to Richard for helping me to understand what goes wrong. Committed as obvious as r12-4703. Tobias ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
commit a31a3d0421f0cf1f7eefacfec8cbf37e7f91600d Author: Tobias Burnus <tob...@codesourcery.com> Date: Tue Oct 26 10:53:53 2021 +0200 Fortran: Fix character(len=cst) dummies with bind(C) [PR102885] PR fortran/102885 gcc/fortran/ChangeLog: * trans-decl.c (gfc_conv_cfi_to_gfc): Properly handle nonconstant character lenghts. gcc/testsuite/ChangeLog: * gfortran.dg/lto/bind-c-char_0.f90: New test. --- gcc/fortran/trans-decl.c | 7 ++++ gcc/testsuite/gfortran.dg/lto/bind-c-char_0.f90 | 49 +++++++++++++++++++++++++ 2 files changed, 56 insertions(+) diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c index fe5511b5285..49ba9060eae 100644 --- a/gcc/fortran/trans-decl.c +++ b/gcc/fortran/trans-decl.c @@ -6837,6 +6837,13 @@ gfc_conv_cfi_to_gfc (stmtblock_t *init, stmtblock_t *finally, gfc_add_modify (&block, sym->ts.u.cl->backend_decl, tmp); } + if (sym->ts.type == BT_CHARACTER + && !INTEGER_CST_P (sym->ts.u.cl->backend_decl)) + { + gfc_conv_string_length (sym->ts.u.cl, NULL, init); + gfc_trans_vla_type_sizes (sym, init); + } + /* gfc->data = cfi->base_addr - or for scalars: gfc = cfi->base_addr. assumed-size/explicit-size arrays end up here for character(len=*) only. */ diff --git a/gcc/testsuite/gfortran.dg/lto/bind-c-char_0.f90 b/gcc/testsuite/gfortran.dg/lto/bind-c-char_0.f90 new file mode 100644 index 00000000000..48b495b1d29 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/lto/bind-c-char_0.f90 @@ -0,0 +1,49 @@ +! { dg-lto-do link } +! { dg-lto-options {{ -O0 -flto }} } +! +! PR fortran/102885 + +module m + use iso_c_binding, only: c_char + implicit none (type, external) + +contains + +! Assumed-shape array, nonallocatable/nonpointer + +subroutine ar3 (xn, n) bind(C) + integer :: n + character(len=n) :: xn(..) + if (size(xn) /= 6) stop + if (len(xn) /= 5) stop + select rank(xn) + rank(1) + xn = ['FDGhf', & + 'hdrhg', & + 'fDgFl', & + 'DFHs3', & + '4a54G', & + 'hSs6k'] + rank default + stop + end select +end + +end + +program main + use m + implicit none (type, external) + character(kind=c_char, len=5) :: str5a6(6) + + ! assumed rank - with array descriptor + + str5a6 = ['DDGhf', & + 'hdrh$', & + 'fDGSl', & + 'DFHs3', & + '43grG', & + 'hFG$k'] + call ar3 (str5a6, 5) + +end