Fix and enable object unloading in GHCi

Fixes #16525 by tracking dependencies between object file symbols and
marking symbol liveness during garbage collection

See Note [Object unloading] in CheckUnload.c for details.

1 files changed, 21 insertions, 6 deletions

diff --git a/rts/Hash.c b/rts/Hash.c
index 31a285aefa..6e1873ff29 100644
--- a/rts/Hash.c
+++ b/rts/Hash.c
@@ -492,6 +492,27 @@ mapHashTableKeys(HashTable *table, void *data, MapHashFnKeys fn)
     }
 }
 
+void
+iterHashTable(HashTable *table, void *data, IterHashFn fn)
+{
+    /* The last bucket with something in it is table->max + table->split - 1 */
+    long segment = (table->max + table->split - 1) / HSEGSIZE;
+    long index = (table->max + table->split - 1) % HSEGSIZE;
+
+    while (segment >= 0) {
+        while (index >= 0) {
+            for (HashList *hl = table->dir[segment][index]; hl != NULL; hl = hl->next) {
+                if (!fn(data, hl->key, hl->data)) {
+                    return;
+                }
+            }
+            index--;
+        }
+        segment--;
+        index = HSEGSIZE - 1;
+    }
+}
+
 /* -----------------------------------------------------------------------------
  * When we initialize a hash table, we set up the first segment as well,
  * initializing all of the first segment's hash buckets to NULL.
@@ -522,12 +543,6 @@ allocHashTable(void)
     return table;
 }
 
-void
-exitHashTable(void)
-{
-    /* nothing to do */
-}
-
 int keyCountHashTable (HashTable *table)
 {
     return table->kcount;