[PATCH 1/5] gdbsupport: Introduce obstack_newvec

[Ilya Leoshkevich <iii@linux.ibm.com>]

obstack_calloc() allocates multiple objects, but doesn't call their
constructors.  obstack_new() allocates a single object and calls its
constructor.  Introduce a new function that does both.
---
 gdbsupport/gdb_obstack.h | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/gdbsupport/gdb_obstack.h b/gdbsupport/gdb_obstack.h
index 5e870cb7981..201ed99216f 100644
--- a/gdbsupport/gdb_obstack.h
+++ b/gdbsupport/gdb_obstack.h
@@ -59,6 +59,32 @@ obstack_new (struct obstack *ob, Args&&... args)
   return object;
 }
 
+/* Allocate NUMBER objects on OB and call their default constructors.  Note
+   that obstack_free() won't call their destructors: this has to be done
+   manually.  */
+
+template <typename T>
+static inline T *
+obstack_newvec (obstack *ob, size_t number)
+{
+  T *objects = static_cast<T *> (obstack_alloc (ob, number * sizeof (T)));
+  for (size_t i = 0; i < number; i++)
+    {
+      try
+	{
+	  new (objects + i) T ();
+	}
+      catch (...)
+	{
+	  for (size_t j = 0; j < i; j++)
+	    (objects + j)->~T ();
+	  obstack_free (ob, objects);
+	  throw;
+	};
+    }
+  return objects;
+}
+
 /* Unless explicitly specified, GDB obstacks always use xmalloc() and
    xfree().  */
 /* Note: ezannoni 2004-02-09: One could also specify the allocation
-- 
2.35.3