From: Harald Anlauf <anlauf@gmx.de>
Date: Wed, 10 Nov 2021 19:30:27 +0000 (+0100)
Subject: Fortran: avoid NULL pointer dereferences
X-Git-Tag: releases/gcc-10.4.0~599
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=651d84ae6cb4299ea91c701ff8d9a7c67e076570;p=thirdparty%2Fgcc.git

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 --git a/gcc/fortran/check.c b/gcc/fortran/check.c
index 5ecfea077a15..f37016bced54 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 48a109c14812..0e5c383f9bda 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;