[gcc r15-7775] Fortran: fix front-end memleak after failure during parsing of NULLIFY

[Harald Anlauf]

https://gcc.gnu.org/g:f7db0263f792466983f53652fb06268767b35305

commit r15-7775-gf7db0263f792466983f53652fb06268767b35305
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Sat Mar 1 15:42:57 2025 +0100

    Fortran: fix front-end memleak after failure during parsing of NULLIFY
    
    gcc/fortran/ChangeLog:
    
            * match.cc (gfc_match_nullify): Free matched expression when
            cleaning up.
            * primary.cc (match_variable): Initialize result to NULL.

Diff:
---
 gcc/fortran/match.cc   | 1 +
 gcc/fortran/primary.cc | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/gcc/fortran/match.cc b/gcc/fortran/match.cc
index c3c330520d6f..ec9e5873204a 100644
--- a/gcc/fortran/match.cc
+++ b/gcc/fortran/match.cc
@@ -5071,6 +5071,7 @@ cleanup:
   new_st.expr1 = NULL;
   gfc_free_expr (new_st.expr2);
   new_st.expr2 = NULL;
+  gfc_free_expr (p);
   return MATCH_ERROR;
 }
 
diff --git a/gcc/fortran/primary.cc b/gcc/fortran/primary.cc
index 8a38720422ec..161d4c269648 100644
--- a/gcc/fortran/primary.cc
+++ b/gcc/fortran/primary.cc
@@ -4298,6 +4298,8 @@ match_variable (gfc_expr **result, int equiv_flag, int host_flag)
   locus where, old_loc;
   match m;
 
+  *result = NULL;
+
   /* Since nothing has any business being an lvalue in a module
      specification block, an interface block or a contains section,
      we force the changed_symbols mechanism to work by setting