https://gcc.gnu.org/g:8923099994f1fe3e808b9f498353c144f1ae0591
commit r15-6925-g8923099994f1fe3e808b9f498353c144f1ae0591
Author: Harald Anlauf <anl...@gmx.de>
Date: Wed Jan 15 19:42:52 2025 +0100
Fortran: reject NULL as source-expr in ALLOCATE with SOURCE= or MOLD=
[PR71884]
PR fortran/71884
gcc/fortran/ChangeLog:
* resolve.cc (resolve_allocate_expr): Reject intrinsic NULL as
source-expr.
gcc/testsuite/ChangeLog:
* gfortran.dg/pr71884.f90: New test.
Diff:
---
gcc/fortran/resolve.cc | 12 ++++++++++++
gcc/testsuite/gfortran.dg/pr71884.f90 | 16 ++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 3e74a2e50883..124f4ac4edcd 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -9433,6 +9433,18 @@ resolve_allocate_expr (gfc_expr *e, gfc_code *code, bool
*array_alloc_wo_spec)
/* Some checks for the SOURCE tag. */
if (code->expr3)
{
+ /* Check F03:C632: "The source-expr shall be a scalar or have the same
+ rank as allocate-object". This would require the MOLD argument to
+ NULL() as source-expr for subsequent checking. However, even the
+ resulting disassociated pointer or unallocated array has no shape that
+ could be used for SOURCE= or MOLD=. */
+ if (code->expr3->expr_type == EXPR_NULL)
+ {
+ gfc_error ("The intrinsic NULL cannot be used as source-expr at %L",
+ &code->expr3->where);
+ goto failure;
+ }
+
/* Check F03:C631. */
if (!gfc_type_compatible (&e->ts, &code->expr3->ts))
{
diff --git a/gcc/testsuite/gfortran.dg/pr71884.f90
b/gcc/testsuite/gfortran.dg/pr71884.f90
new file mode 100644
index 000000000000..015a10290a15
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr71884.f90
@@ -0,0 +1,16 @@
+! { dg-do compile }
+! PR fortran/71884 - reject NULL as source-expr in ALLOCATE with SOURCE= or
MOLD=
+!
+! Contributed by G.Steinmetz
+
+program p
+ real, allocatable :: a
+ real, pointer :: b
+ class(*), allocatable :: x
+ class(*), pointer :: y
+
+ allocate (x, source=null()) ! { dg-error "NULL cannot be used as
source-expr" }
+ allocate (y, source=null(b)) ! { dg-error "NULL cannot be used as
source-expr" }
+ allocate (x, mold=null(b)) ! { dg-error "NULL cannot be used as
source-expr" }
+ allocate (y, mold=null()) ! { dg-error "NULL cannot be used as
source-expr" }
+end
