[gcc r9-9162] PR fortran/78746 - invalid access after error recovery

[Harald Anlauf]

https://gcc.gnu.org/g:ef7d053ea33cc9abc7fc413213705a16478fefc4

commit r9-9162-gef7d053ea33cc9abc7fc413213705a16478fefc4
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Wed Jan 6 19:37:11 2021 +0100

    PR fortran/78746 - invalid access after error recovery
    
    The error recovery after an invalid reference to an undefined CLASS
    during a TYPE declaration lead to an invalid access.  Add a check.
    
    gcc/fortran/ChangeLog:
    
            * resolve.c (resolve_component): Add check for valid CLASS
            reference before trying to access CLASS data.
    
    (cherry picked from commit 8b6f1e8f97fe0d435d334075821149dbd85c8266)

Diff:
---
 gcc/fortran/resolve.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index aa27cb206a1..8ddef4f682b 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -13974,7 +13974,7 @@ resolve_component (gfc_component *c, gfc_symbol *sym)
   /* F2008, C448.  */
   if (c->ts.type == BT_CLASS)
     {
-      if (CLASS_DATA (c))
+      if (c->attr.class_ok && CLASS_DATA (c))
 	{
 	  attr = &(CLASS_DATA (c)->attr);