https://gcc.gnu.org/g:c9c7f3cf6e5c671509dd679f537c052b646169a4
commit r16-9177-gc9c7f3cf6e5c671509dd679f537c052b646169a4 Author: Harald Anlauf <[email protected]> Date: Thu Jun 25 22:55:47 2026 +0200 Fortran: -fc-prototypes, deferred shape and deferred length dummies [PR125902] Commit r17-1785 fixed the C prototypes emitted by -fc-prototypes for procedure interfaces with deferred shape and deferred length dummies, but did not consistently detect when "#include <ISO_Fortran_binding.h>" was needed. Use common helper function to handle this. PR fortran/125902 gcc/fortran/ChangeLog: * dump-parse-tree.cc (needs_CFI_cdesc): New helper function to determine when struct CFI_cdesc_t is used. (has_cfi_cdesc): Use it here... (get_c_type_name): ... and here. gcc/testsuite/ChangeLog: * gfortran.dg/c-prototypes_2.F90: New test. (cherry picked from commit fdffb66e398d4440116a7d7834aae11053973ffe) Diff: --- gcc/fortran/dump-parse-tree.cc | 21 ++++++++++++----- gcc/testsuite/gfortran.dg/c-prototypes_2.F90 | 35 ++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+), 6 deletions(-) diff --git a/gcc/fortran/dump-parse-tree.cc b/gcc/fortran/dump-parse-tree.cc index 4f494e20886f..92f99558d8c7 100644 --- a/gcc/fortran/dump-parse-tree.cc +++ b/gcc/fortran/dump-parse-tree.cc @@ -4129,6 +4129,19 @@ static void show_external_symbol (gfc_gsymbol *, void *); static void write_type (gfc_symbol *sym); static void write_funptr_fcn (gfc_symbol *); +/* Helper function determining if the characteristics of a formal argument of a + bind(C) procedure is such that its C prototype needs struct CFI_cdesc_t. */ + +static bool +needs_CFI_cdesc (gfc_typespec *ts, gfc_array_spec *as) +{ + return ((as && (as->type == AS_ASSUMED_RANK + || as->type == AS_ASSUMED_SHAPE + || as->type == AS_DEFERRED)) + || (ts->type == BT_CHARACTER + && (ts->deferred || ts->u.cl->length == NULL))); +} + /* Do we need to write out an #include <ISO_Fortran_binding.h> or not? */ static void @@ -4153,7 +4166,7 @@ has_cfi_cdesc (gfc_gsymbol *gsym, void *p) { gfc_symbol *s; s = f->sym; - if (s->as && (s->as->type == AS_ASSUMED_RANK || s->as->type == AS_ASSUMED_SHAPE)) + if (needs_CFI_cdesc (&s->ts, s->as)) { *data_p = true; return; @@ -4286,11 +4299,7 @@ get_c_type_name (gfc_typespec *ts, gfc_array_spec *as, const char **pre, *post = ""; *type_name = "<error>"; - if ((as && (as->type == AS_ASSUMED_RANK - || as->type == AS_ASSUMED_SHAPE - || as->type == AS_DEFERRED)) - || (ts->type == BT_CHARACTER - && (ts->deferred || ts->u.cl->length == NULL))) + if (needs_CFI_cdesc (ts, as)) { *asterisk = true; *post = ""; diff --git a/gcc/testsuite/gfortran.dg/c-prototypes_2.F90 b/gcc/testsuite/gfortran.dg/c-prototypes_2.F90 new file mode 100644 index 000000000000..8530956f956e --- /dev/null +++ b/gcc/testsuite/gfortran.dg/c-prototypes_2.F90 @@ -0,0 +1,35 @@ +! { dg-do compile } +! { dg-options "-fc-prototypes" } +! +! PR fortran/125902 +! +! Test -fc-prototypes for assumed length character dummy, header include + +subroutine sub (b) bind(C) + character(*) :: b +end subroutine sub + +#if 0 +!{ dg-begin-multiline-output "" } +#include <stddef.h> +#ifdef __cplusplus +#include <complex> +#define __GFORTRAN_FLOAT_COMPLEX std::complex<float> +#define __GFORTRAN_DOUBLE_COMPLEX std::complex<double> +#define __GFORTRAN_LONG_DOUBLE_COMPLEX std::complex<long double> +extern "C" { +#else +#define __GFORTRAN_FLOAT_COMPLEX float _Complex +#define __GFORTRAN_DOUBLE_COMPLEX double _Complex +#define __GFORTRAN_LONG_DOUBLE_COMPLEX long double _Complex +#endif + +#include <ISO_Fortran_binding.h> + +void sub (CFI_cdesc_t *b); + +#ifdef __cplusplus +} +#endif +!{ dg-end-multiline-output "" } +#endif
