[binutils-gdb] arc gas: don't leak arc_opcode_hash memory

[binutils-gdb] arc gas: don't leak arc_opcode_hash memory

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=a51628a9d49bf7abb89b71032aa38d7f596be674

commit a51628a9d49bf7abb89b71032aa38d7f596be674
Author: Alan Modra <amodra@gmail.com>
Date:   Thu Jul 7 22:09:28 2022 +0930

    arc gas: don't leak arc_opcode_hash memory
    
    The arc opcode hash table has entries that have a realloc'd field.
    This doesn't lend itself to obstack allocation, so freeing must be
    done with a purpose built hashtab del_f.
    
            * config/tc-arc.c (arc_opcode_free): New function.
            (md_begin): Pass the above as del_f to htab_create_alloc.
            (arc_md_end): New function.
            * config/tc-arc.h (arc_md_end): Declare.
            (md_end): Define.

Diff:
---
 gas/config/tc-arc.c | 21 ++++++++++++++++++++-
 gas/config/tc-arc.h |  3 +++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/gas/config/tc-arc.c b/gas/config/tc-arc.c
index 6c5b1d68078..fd648b742b4 100644
--- a/gas/config/tc-arc.c
+++ b/gas/config/tc-arc.c
@@ -774,6 +774,15 @@ arc_insert_opcode (const struct arc_opcode *opcode)
   entry->count++;
 }
 
+static void
+arc_opcode_free (void *elt)
+{
+  string_tuple_t *tuple = (string_tuple_t *) elt;
+  struct arc_opcode_hash_entry *entry = (void *) tuple->value;
+  free (entry->opcode);
+  free (entry);
+  free (tuple);
+}
 
 /* Like md_number_to_chars but for middle-endian values.  The 4-byte limm
    value, is encoded as 'middle-endian' for a little-endian target.  This
@@ -2605,7 +2614,8 @@ md_begin (void)
   bfd_set_private_flags (stdoutput, selected_cpu.eflags);
 
   /* Set up a hash table for the instructions.  */
-  arc_opcode_hash = str_htab_create ();
+  arc_opcode_hash = htab_create_alloc (16, hash_string_tuple, eq_string_tuple,
+				       arc_opcode_free, xcalloc, free);
 
   /* Initialize the hash table with the insns.  */
   do
@@ -2710,6 +2720,15 @@ md_begin (void)
   declare_addrtype ("cxd", ARC_NPS400_ADDRTYPE_CXD);
 }
 
+void
+arc_md_end (void)
+{
+  htab_delete (arc_opcode_hash);
+  htab_delete (arc_reg_hash);
+  htab_delete (arc_aux_hash);
+  htab_delete (arc_addrtype_hash);
+}
+
 /* Write a value out to the object file, using the appropriate
    endianness.  */
 
diff --git a/gas/config/tc-arc.h b/gas/config/tc-arc.h
index 29b4582ae22..d7b989e7f19 100644
--- a/gas/config/tc-arc.h
+++ b/gas/config/tc-arc.h
@@ -268,4 +268,7 @@ struct arc_relax_type
   int nflg;
 };
 
+extern void arc_md_end (void);
+#define md_end arc_md_end
+
 #endif