[gcc r10-10272] Fortran: avoid NULL pointer dereferences

[gcc r10-10272] Fortran: avoid NULL pointer dereferences

[Harald Anlauf]

https://gcc.gnu.org/g:651d84ae6cb4299ea91c701ff8d9a7c67e076570

commit r10-10272-g651d84ae6cb4299ea91c701ff8d9a7c67e076570
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Wed Nov 10 20:30:27 2021 +0100

    Fortran: avoid NULL pointer dereferences
    
    CLASS(), PARAMETER is not yet properly implemented in gfortran.  Using it
    in declarations could lead to subsequent NULL pointer dereferences during
    checking or simplification of expressions involving those CLASS variables.
    
    gcc/fortran/ChangeLog:
    
            PR fortran/103137
            PR fortran/103138
            * check.c (gfc_check_shape): Avoid NULL pointer dereference on
            missing ref.
            * simplify.c (gfc_simplify_cshift): Avoid NULL pointer dereference
            when shape not set.
            (gfc_simplify_transpose): Likewise.
    
    (cherry picked from commit abc2f01914d6c4703de26c402fb579a9a2d0dba4)

Diff:
---
 gcc/fortran/check.c    | 3 +++
 gcc/fortran/simplify.c | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/gcc/fortran/check.c b/gcc/fortran/check.c
index 5ecfea077a1..f37016bced5 100644
--- a/gcc/fortran/check.c
+++ b/gcc/fortran/check.c
@@ -5085,6 +5085,9 @@ gfc_check_shape (gfc_expr *source, gfc_expr *kind)
   if (source->rank == 0 || source->expr_type != EXPR_VARIABLE)
     return true;
 
+  if (source->ref == NULL)
+    return false;
+
   ar = gfc_find_array_ref (source);
 
   if (ar->as && ar->as->type == AS_ASSUMED_SIZE && ar->type == AR_FULL)
diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index 48a109c1481..0e5c383f9bd 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -2077,6 +2077,9 @@ gfc_simplify_cshift (gfc_expr *array, gfc_expr *shift, gfc_expr *dim)
   else
     which = 0;
 
+  if (array->shape == NULL)
+    return NULL;
+
   gfc_array_size (array, &size);
   arraysize = mpz_get_ui (size);
   mpz_clear (size);
@@ -8076,6 +8079,9 @@ gfc_simplify_transpose (gfc_expr *matrix)
 
   gcc_assert (matrix->rank == 2);
 
+  if (matrix->shape == NULL)
+    return NULL;
+
   result = gfc_get_array_expr (matrix->ts.type, matrix->ts.kind,
 			       &matrix->where);
   result->rank = 2;