Playing with the PR92284 test case revealed two issues related to
gfc_desc_to_cfi_desc:
* Access of uninitialized memory – copying the array bounds (in
libgfortran) does not make sense for unallocted allocatables and
nullified pointers. Hence, check for "<descr>.data == NULL".
* There is a memory leak. I misunderstood the dump when fixing PR91863
(rev.277502).
https://gcc.gnu.org/ml/gcc-patches/2019-10/msg01651.html
Regarding the latter: If one passed gfc_desc_to_cfi_desc a pointer var,
pointing to NULL, as CFI (Bind(C) array descriptor) argument,
libgfortran allocates the memory for the descriptor – which at some
point has to be freed.
Contrary to the original version, one can free that memory
unconditionally. (Not only because "free" handles NULL pointers but –
unless "malloc" failed – we know that ptr has been malloced.) I also
tried to make the comments a bit clearer.
Build and regtested.
OK for trunk and GCC 9 (the latter is also affected)?
Tobias
PR: Related pending patch:
https://gcc.gnu.org/ml/gcc-patches/2019-10/msg02148.html
Also missing: At the end of a bind(C) procedure written in Fortran,
allocatable/pointers array arguments need get updated: the "data" and
the bounds part of the array descriptor might have changed while running
the procedure body. Cf. this PR and PR 92189
gcc/fortran/
PR fortran/92284.
* trans-expr.c (gfc_conv_gfc_desc_to_cfi_desc): Free CFI descriptor
at the end; partial revised revert of Rev. 277502.
libgfortran/
PR fortran/92284.
* runtime/ISO_Fortran_binding.c (gfc_desc_to_cfi_desc):
gcc/testsuite/
PR fortran/92284.
* gfortran.dg/bind-c-intent-out.f90: Update expected dump;
extend comment.
* gfortran.dg/bind_c_array_params_3.f90: New.
* gfortran.dg/bind_c_array_params_3_aux.c: New.
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index 7eba1bbd082..f800faaa4e5 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -5303,13 +5303,13 @@ gfc_conv_gfc_desc_to_cfi_desc (gfc_se *parmse, gfc_expr *e, gfc_symbol *fsym)
/* Now pass the gfc_descriptor by reference. */
parmse->expr = gfc_build_addr_expr (NULL_TREE, parmse->expr);
- /* Variables to point to the gfc and CFI descriptors. */
+ /* Variables to point to the gfc and CFI descriptors; cfi = NULL implies
+ that the CFI descriptor is allocated by the gfor_fndecl_gfc_to_cfi call. */
gfc_desc_ptr = parmse->expr;
cfi_desc_ptr = gfc_create_var (pvoid_type_node, "cfi");
- gfc_add_modify (&parmse->pre, cfi_desc_ptr,
- build_int_cst (pvoid_type_node, 0));
+ gfc_add_modify (&parmse->pre, cfi_desc_ptr, null_pointer_node);
- /* Allocate the CFI descriptor and fill the fields. */
+ /* Allocate the CFI descriptor itself and fill the fields. */
tmp = gfc_build_addr_expr (NULL_TREE, cfi_desc_ptr);
tmp = build_call_expr_loc (input_location,
gfor_fndecl_gfc_to_cfi, 2, tmp, gfc_desc_ptr);
@@ -5324,6 +5324,10 @@ gfc_conv_gfc_desc_to_cfi_desc (gfc_se *parmse, gfc_expr *e, gfc_symbol *fsym)
/* The CFI descriptor is passed to the bind_C procedure. */
parmse->expr = cfi_desc_ptr;
+ /* Free the CFI descriptor. */
+ tmp = gfc_call_free (cfi_desc_ptr);
+ gfc_prepend_expr_to_block (&parmse->post, tmp);
+
/* Transfer values back to gfc descriptor. */
tmp = gfc_build_addr_expr (NULL_TREE, parmse->expr);
tmp = build_call_expr_loc (input_location,
diff --git a/gcc/testsuite/gfortran.dg/bind-c-intent-out.f90 b/gcc/testsuite/gfortran.dg/bind-c-intent-out.f90
index 493e546d45d..39822c0753a 100644
--- a/gcc/testsuite/gfortran.dg/bind-c-intent-out.f90
+++ b/gcc/testsuite/gfortran.dg/bind-c-intent-out.f90
@@ -35,7 +35,8 @@ end program p
! the intent(out) implies freeing in the callee (!), hence the "free"
! It is the only 'free' as 'a' is part of the main program and, hence, implicitly has the SAVE attribute.
! The 'cfi = 0' appears before the call due to the deallocate and when preparing the C descriptor
+! As cfi (i.e. the descriptor itself) is allocated in libgomp, it has to be freed after the call.
-! { dg-final { scan-tree-dump-times "__builtin_free" 1 "original" } }
-! { dg-final { scan-tree-dump-times "__builtin_free \\(cfi\\.\[0-9\]+\\);" 1 "original" } }
+! { dg-final { scan-tree-dump-times "__builtin_free" 2 "original" } }
+! { dg-final { scan-tree-dump-times "__builtin_free \\(cfi\\.\[0-9\]+\\);" 2 "original" } }
! { dg-final { scan-tree-dump-times "cfi\\.\[0-9\]+ = 0B;" 2 "original" } }
diff --git a/gcc/testsuite/gfortran.dg/bind_c_array_params_3.f90 b/gcc/testsuite/gfortran.dg/bind_c_array_params_3.f90
new file mode 100644
index 00000000000..d5bad7d03f2
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bind_c_array_params_3.f90
@@ -0,0 +1,39 @@
+! { dg-do run }
+! { dg-additional-sources bind_c_array_params_3_aux.c }
+!
+! PR fortran/92284
+!
+! Contributed by José Rui Faustino de Sousa
+!
+program arr_p
+ use, intrinsic :: iso_c_binding, only: c_int
+ implicit none (type, external)
+
+ integer(kind=c_int), pointer :: arr(:)
+ integer :: i
+
+ nullify(arr)
+ call arr_set(arr)
+
+ if (.not.associated(arr)) stop 1
+ if (lbound(arr,dim=1) /= 1) stop 2
+ if (ubound(arr,dim=1) /= 9) stop 3
+ if (any (arr /= [(i, i=0,8)])) stop 4
+ deallocate(arr)
+
+contains
+
+ subroutine arr_set(this) !bind(c)
+ integer(kind=c_int), pointer, intent(out) :: this(:)
+
+ interface
+ subroutine arr_set_c(this) bind(c)
+ use, intrinsic :: iso_c_binding, only: c_int
+ implicit none
+ integer(kind=c_int), pointer, intent(out) :: this(:)
+ end subroutine arr_set_c
+ end interface
+
+ call arr_set_c(this)
+ end subroutine arr_set
+end program arr_p
diff --git a/gcc/testsuite/gfortran.dg/bind_c_array_params_3_aux.c b/gcc/testsuite/gfortran.dg/bind_c_array_params_3_aux.c
new file mode 100644
index 00000000000..6e13aa3b2ef
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bind_c_array_params_3_aux.c
@@ -0,0 +1,27 @@
+/* Used by bind_c_array_params_3.f90. */
+/* PR fortran/92284. */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+
+#include "ISO_Fortran_binding.h"
+
+void arr_set_c(CFI_cdesc_t*);
+
+void arr_set_c(CFI_cdesc_t *arr){
+ int i, stat, *auxp = NULL;
+ CFI_index_t lb[] = {1};
+ CFI_index_t ub[] = {9};
+
+ assert(arr);
+ assert(arr->rank==1);
+ assert(!arr->base_addr);
+ stat = CFI_allocate(arr, lb, ub, sizeof(int));
+ assert(stat==CFI_SUCCESS);
+ auxp = (int*)arr->base_addr;
+ assert(auxp);
+ for(i=0; i<ub[0]-lb[0]+1; i++) auxp[i]=i;
+ return;
+}
+
diff --git a/libgfortran/runtime/ISO_Fortran_binding.c b/libgfortran/runtime/ISO_Fortran_binding.c
index 695ef57ac32..c71d8e89453 100644
--- a/libgfortran/runtime/ISO_Fortran_binding.c
+++ b/libgfortran/runtime/ISO_Fortran_binding.c
@@ -119,24 +119,25 @@ gfc_desc_to_cfi_desc (CFI_cdesc_t **d_ptr, const gfc_array_void *s)
d->type = (CFI_type_t)(d->type
+ ((CFI_type_t)d->elem_len << CFI_type_kind_shift));
- /* Full pointer or allocatable arrays retain their lower_bounds. */
- for (n = 0; n < GFC_DESCRIPTOR_RANK (s); n++)
- {
- if (d->attribute != CFI_attribute_other)
- d->dim[n].lower_bound = (CFI_index_t)GFC_DESCRIPTOR_LBOUND(s, n);
- else
- d->dim[n].lower_bound = 0;
-
- /* Assumed size arrays have gfc ubound == 0 and CFI extent = -1. */
- if ((n == GFC_DESCRIPTOR_RANK (s) - 1)
- && GFC_DESCRIPTOR_LBOUND(s, n) == 1
- && GFC_DESCRIPTOR_UBOUND(s, n) == 0)
- d->dim[n].extent = -1;
- else
- d->dim[n].extent = (CFI_index_t)GFC_DESCRIPTOR_UBOUND(s, n)
- - (CFI_index_t)GFC_DESCRIPTOR_LBOUND(s, n) + 1;
- d->dim[n].sm = (CFI_index_t)(GFC_DESCRIPTOR_STRIDE(s, n) * s->span);
- }
+ if (d->base_addr)
+ /* Full pointer or allocatable arrays retain their lower_bounds. */
+ for (n = 0; n < GFC_DESCRIPTOR_RANK (s); n++)
+ {
+ if (d->attribute != CFI_attribute_other)
+ d->dim[n].lower_bound = (CFI_index_t)GFC_DESCRIPTOR_LBOUND(s, n);
+ else
+ d->dim[n].lower_bound = 0;
+
+ /* Assumed size arrays have gfc ubound == 0 and CFI extent = -1. */
+ if (n == GFC_DESCRIPTOR_RANK (s) - 1
+ && GFC_DESCRIPTOR_LBOUND(s, n) == 1
+ && GFC_DESCRIPTOR_UBOUND(s, n) == 0)
+ d->dim[n].extent = -1;
+ else
+ d->dim[n].extent = (CFI_index_t)GFC_DESCRIPTOR_UBOUND(s, n)
+ - (CFI_index_t)GFC_DESCRIPTOR_LBOUND(s, n) + 1;
+ d->dim[n].sm = (CFI_index_t)(GFC_DESCRIPTOR_STRIDE(s, n) * s->span);
+ }
if (*d_ptr == NULL)
*d_ptr = d;
