Make psymtab_storage::free_psymtabs private

This adds a new psymtab allocation method to psymtab_storage and
changes the free_psymtabs member to be private.  While not strictly
necessary, this seems like a decent cleanup, and also makes it simpler
to move psymtabs off of obstacks entirely, should that prove
desirable.

gdb/ChangeLog
2019-01-10  Tom Tromey  <tom@tromey.com>

	* psymtab.h (psymtab_storage::allocate_psymtab): New method.
	<free_psymtabs>: Now private.
	* psymtab.c (psymtab_storage::allocate_psymtab): Implement.
	(allocate_psymtab): Use new method.

1 files changed, 10 insertions, 4 deletions

diff --git a/gdb/psymtab.h b/gdb/psymtab.h
index 57570e3..a21e88f 100644
--- a/gdb/psymtab.h
+++ b/gdb/psymtab.h
@@ -71,6 +71,12 @@ public:
     return OBSTACK_CALLOC (obstack (), number, struct partial_symtab *);
   }
 
+  /* Allocate a new psymtab on the psymtab obstack.  The new psymtab
+     will be linked in to the "psymtabs" list, but otherwise all other
+     fields will be zero.  */
+
+  struct partial_symtab *allocate_psymtab ();
+
 
   /* Each objfile points to a linked list of partial symtabs derived from
      this file, one partial symtab structure for each compilation unit
@@ -85,10 +91,6 @@ public:
 
   struct addrmap *psymtabs_addrmap = nullptr;
 
-  /* List of freed partial symtabs, available for re-use.  */
-
-  struct partial_symtab *free_psymtabs = nullptr;
-
   /* A byte cache where we can stash arbitrary "chunks" of bytes that
      will not change.  */
 
@@ -102,6 +104,10 @@ public:
 
 private:
 
+  /* List of freed partial symtabs, available for re-use.  */
+
+  struct partial_symtab *free_psymtabs = nullptr;
+
   /* The obstack where allocations are made.  */
 
   struct obstack *m_obstack;