fortran: ICE equivalence with an element of an array PR94030

Deferred size arrays can not be used in equivalance statements.

gcc/fortran/ChangeLog:

	PR fortran/94030
	* resolve.c (resolve_equivalence): Correct formatting
	around the label "identical_types".  Instead of using
	gfc_resolve_array_spec use is_non_constants_shape_array
	to determine whether the array can be used in a in an
	equivalence statement.

gcc/testsuite/ChangeLog:

	PR fortran/94030
	* gfortran.dg/pr94030_1.f90
	* gfortran.dg/pr94030_2.f90

5 files changed, 63 insertions, 3 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 2539e51..1aa71d8 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,12 @@
+2020-04-02 Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/94030
+	* resolve.c (resolve_equivalence): Correct formatting
+	around the label "identical_types".  Instead of using
+	gfc_resolve_array_spec use is_non_constants_shape_array
+	to determine whether the array can be used in a in an
+	equivalence statement.
+
 2020-04-01  Mark Eggleston  <mark.eggleston@codethink.com>
 
 	PR fortran/94386
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index b6277d2..79b0d72 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -16873,7 +16873,8 @@ resolve_equivalence (gfc_equiv *eq)
 	  && !gfc_notify_std (GFC_STD_GNU, msg, sym->name, &e->where))
 		continue;
 
-  identical_types:
+identical_types:
+
       last_ts =&sym->ts;
       last_where = &e->where;
 
@@ -16881,8 +16882,7 @@ resolve_equivalence (gfc_equiv *eq)
 	continue;
 
       /* Shall not be an automatic array.  */
-      if (e->ref->type == REF_ARRAY
-	  && !gfc_resolve_array_spec (e->ref->u.ar.as, 1))
+      if (e->ref->type == REF_ARRAY && is_non_constant_shape_array (sym))
 	{
 	  gfc_error ("Array %qs at %L with non-constant bounds cannot be "
 		     "an EQUIVALENCE object", sym->name, &e->where);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ff021ac..2a686d2 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2020-04-02  Mark Eggleston  <mark.eggleston@codethink.com>
+	Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	PR fortran/94030
+	* gfortran.dg/pr94030_1.f90: New test.
+	* gfortran.dg/pr94030_2.f90: New test.
+
 2020-04-01  Iain Buclaw  <ibuclaw@gdcproject.org>
 
 	PR d/94315
diff --git a/gcc/testsuite/gfortran.dg/pr94030_1.f90 b/gcc/testsuite/gfortran.dg/pr94030_1.f90
new file mode 100644
index 0000000..e63d3cc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr94030_1.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+!
+
+subroutine f(n)
+  integer :: n
+  integer :: arr(n)
+  integer :: i
+  equivalence (i, arr(1))
+end
+
+! { dg-error "Array 'arr' at .1. with non-constant bounds cannot be an EQUIVALENCE object" " " { target *-*-* } 8 }
diff --git a/gcc/testsuite/gfortran.dg/pr94030_2.f90 b/gcc/testsuite/gfortran.dg/pr94030_2.f90
new file mode 100644
index 0000000..84bfdea
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr94030_2.f90
@@ -0,0 +1,33 @@
+! { dg-do compile }
+!
+! Provided by Steve Kargl.
+
+subroutine foo(n,m)
+  integer, intent(in) :: n, m
+  integer a(n)
+  real b(n)
+  equivalence(a,b)
+  if (m /= 2) then
+      a = 1
+      print *, a(1)
+  else
+      b = 42.
+      print *, b(1)
+   end if
+end subroutine 
+
+subroutine bar(m)
+  integer, intent(in) :: m
+  integer x(8)
+  real y(8)
+  equivalence(x,y)
+  if (m /= 2) then
+      x = 1
+      print *, x(1)
+  else
+      y = 42.
+      print *, y(1)
+   end if
+end subroutine 
+
+! { dg-error "Array '.' at .1. with non-constant bounds cannot be an EQUIVALENCE object" " " { target *-*-* } 9 }