Use new and delete for psymtabs

This changes psymtabs to be allocated with new and destroyed with
delete.  As a consequence, the psymtab free-list is also removed.

The motivation for this is to let symbol readers subclass
partial_symtab.

gdb/ChangeLog
2020-01-26  Tom Tromey  <tom@tromey.com>

	* mdebugread.c (parse_partial_symbols): Use discard_psymtab.
	* psymtab.h (class psymtab_storage) <free_psymtabs>: Remove.
	* psymtab.c (psymtab_storage): Delete psymtabs.
	(psymtab_storage::allocate_psymtab): Use new.
	(psymtab_storage::discard_psymtab): Use delete.
	* psympriv.h (struct partial_symtab): Add constructor and
	initializers.

Change-Id: I4e78ac538fc0ea52b57489c1afb8f935a30941ef

1 files changed, 9 insertions, 16 deletions

diff --git a/gdb/psymtab.c b/gdb/psymtab.c
index 18580f5..5f42867 100644
--- a/gdb/psymtab.c
+++ b/gdb/psymtab.c
@@ -64,6 +64,13 @@ psymtab_storage::psymtab_storage ()
 
 psymtab_storage::~psymtab_storage ()
 {
+  partial_symtab *iter = psymtabs;
+  while (iter != nullptr)
+    {
+      partial_symtab *next = iter->next;
+      delete iter;
+      iter = next;
+    }
 }
 
 /* See psymtab.h.  */
@@ -71,17 +78,7 @@ psymtab_storage::~psymtab_storage ()
 struct partial_symtab *
 psymtab_storage::allocate_psymtab ()
 {
-  struct partial_symtab *psymtab;
-
-  if (free_psymtabs != nullptr)
-    {
-      psymtab = free_psymtabs;
-      free_psymtabs = psymtab->next;
-    }
-  else
-    psymtab = XOBNEW (obstack (), struct partial_symtab);
-
-  memset (psymtab, 0, sizeof (struct partial_symtab));
+  struct partial_symtab *psymtab = new struct partial_symtab;
 
   psymtab->next = psymtabs;
   psymtabs = psymtab;
@@ -1705,11 +1702,7 @@ psymtab_storage::discard_psymtab (struct partial_symtab *pst)
   while ((*prev_pst) != pst)
     prev_pst = &((*prev_pst)->next);
   (*prev_pst) = pst->next;
-
-  /* Next, put it on a free list for recycling.  */
-
-  pst->next = free_psymtabs;
-  free_psymtabs = pst;
+  delete pst;
 }