[gcc r11-9419] Fortran: CASE selector expressions must be scalar

[gcc r11-9419] Fortran: CASE selector expressions must be scalar

[Harald Anlauf]

https://gcc.gnu.org/g:3c830e6d17b12aff2875b6e80e77774404f09153

commit r11-9419-g3c830e6d17b12aff2875b6e80e77774404f09153
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Mon Dec 20 22:01:05 2021 +0100

    Fortran: CASE selector expressions must be scalar
    
    gcc/fortran/ChangeLog:
    
            PR fortran/103776
            * match.c (match_case_selector): Reject expressions in CASE
            selector which are not scalar.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/103776
            * gfortran.dg/select_10.f90: New test.
    
    (cherry picked from commit 5474092c9afbd76cbd457facce3757d8d2fad07b)

Diff:
---
 gcc/fortran/match.c                     | 13 +++++++++++++
 gcc/testsuite/gfortran.dg/select_10.f90 | 25 +++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/gcc/fortran/match.c b/gcc/fortran/match.c
index 74d03d062b3..3e8a3d14e67 100644
--- a/gcc/fortran/match.c
+++ b/gcc/fortran/match.c
@@ -6105,6 +6105,19 @@ match_case_selector (gfc_case **cp)
 	}
     }
 
+  if (c->low && c->low->rank != 0)
+    {
+      gfc_error ("Expression in CASE selector at %L must be scalar",
+		 &c->low->where);
+      goto cleanup;
+    }
+  if (c->high && c->high->rank != 0)
+    {
+      gfc_error ("Expression in CASE selector at %L must be scalar",
+		 &c->high->where);
+      goto cleanup;
+    }
+
   *cp = c;
   return MATCH_YES;
 
diff --git a/gcc/testsuite/gfortran.dg/select_10.f90 b/gcc/testsuite/gfortran.dg/select_10.f90
new file mode 100644
index 00000000000..2d9b0170ce9
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/select_10.f90
@@ -0,0 +1,25 @@
+! { dg-do compile }
+! PR fortran/103776 - ICE in gfc_compare_string
+! Contributed by G.Steinmetz
+
+program p
+  integer :: n
+  select case (n)
+  case ([1])        ! { dg-error "must be scalar" }
+  end select
+  select case (n)
+  case (:[2])       ! { dg-error "must be scalar" }
+  end select
+  select case (n)
+  case (['1'])      ! { dg-error "must be scalar" }
+  end select
+  select case (n)
+  case (['1']:2)    ! { dg-error "must be scalar" }
+  end select
+  select case (n)
+  case(['1']:['2']) ! { dg-error "must be scalar" }
+  end select
+  select case (n)
+  case(1:['2'])     ! { dg-error "must be scalar" }
+  end select
+end