On Fri, Jan 10, 2025 at 05:19:34PM +0000, Paul Richard Thomas wrote:
>
> As of today, Gerhard Steinmetz has no fewer than 33 regressions to his name
> out of a total of 54 for fortran and libgfortran. It's time that some of
> these bugs are swatted, I think :-)
>
This patch fixes PR71844. As the error message indicates,
the source-expr in 'allocate(x, source=null())' cannot
be null().
diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index dab0c3af601..538917fe56a 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -8965,6 +8965,13 @@ resolve_allocate_expr (gfc_expr *e, gfc_code *code, bool
*array_alloc_wo_spec)
gfc_component *c;
bool t;
+ /* source-expr in either SOURCE= or MODE= cannot be NULL(). */
+ if (code->expr3 && code->expr3->expr_type == EXPR_NULL)
+ {
+ gfc_error ("Source-expr at %L cannot be NULL()", &code->expr3->where);
+ goto failure;
+ }
+
/* Mark the utmost array component as being in allocate to allow DIMEN_STAR
checking of coarrays. */
for (ref = e->ref; ref; ref = ref->next)
diff --git a/gcc/testsuite/gfortran.dg/pr71844.f90
b/gcc/testsuite/gfortran.dg/pr71844.f90
new file mode 100644
index 00000000000..af990f32fbb
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr71844.f90
@@ -0,0 +1,10 @@
+!
+! { dg-do compile }
+!
+program p
+ class(*), allocatable :: x, y
+ character(:), allocatable :: z
+ allocate (x, source=null()) ! { dg-error "cannot be NULL" }
+ allocate (y, mold=null()) ! { dg-error "cannot be NULL" }
+ allocate (character(*) :: z) ! { dg-error "Incompatible allocate-object" }
+end
--
Steve
