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diff --git a/gdb/common/vec.c b/gdb/common/vec.c
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+/* Vector API for GDB.
+ Copyright (C) 2004-2012 Free Software Foundation, Inc.
+ Contributed by Nathan Sidwell <nathan@codesourcery.com>
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#ifdef GDBSERVER
+#include "server.h"
+#else
+#include "defs.h"
+#endif
+
+#include "vec.h"
+
+struct vec_prefix
+{
+ unsigned num;
+ unsigned alloc;
+ void *vec[1];
+};
+
+/* Calculate the new ALLOC value, making sure that abs(RESERVE) slots
+ are free. If RESERVE < 0 grow exactly, otherwise grow
+ exponentially. */
+
+static inline unsigned
+calculate_allocation (const struct vec_prefix *pfx, int reserve)
+{
+ unsigned alloc = 0;
+ unsigned num = 0;
+
+ if (pfx)
+ {
+ alloc = pfx->alloc;
+ num = pfx->num;
+ }
+ else if (!reserve)
+ /* If there's no prefix, and we've not requested anything, then we
+ will create a NULL vector. */
+ return 0;
+
+ /* We must have run out of room. */
+ gdb_assert (alloc - num < (unsigned)(reserve < 0 ? -reserve : reserve));
+
+ if (reserve < 0)
+ /* Exact size. */
+ alloc = num + -reserve;
+ else
+ {
+ /* Exponential growth. */
+ if (!alloc)
+ alloc = 4;
+ else if (alloc < 16)
+ /* Double when small. */
+ alloc = alloc * 2;
+ else
+ /* Grow slower when large. */
+ alloc = (alloc * 3 / 2);
+
+ /* If this is still too small, set it to the right size. */
+ if (alloc < num + reserve)
+ alloc = num + reserve;
+ }
+ return alloc;
+}
+
+/* Ensure there are at least abs(RESERVE) free slots in VEC. If
+ RESERVE < 0 grow exactly, else grow exponentially. As a special
+ case, if VEC is NULL, and RESERVE is 0, no vector will be created. */
+
+void *
+vec_p_reserve (void *vec, int reserve)
+{
+ return vec_o_reserve (vec, reserve,
+ offsetof (struct vec_prefix, vec), sizeof (void *));
+}
+
+/* As vec_p_reserve, but for object vectors. The vector's trailing
+ array is at VEC_OFFSET offset and consists of ELT_SIZE sized
+ elements. */
+
+void *
+vec_o_reserve (void *vec, int reserve, size_t vec_offset, size_t elt_size)
+{
+ struct vec_prefix *pfx = vec;
+ unsigned alloc = calculate_allocation (pfx, reserve);
+
+ if (!alloc)
+ return NULL;
+
+ vec = xrealloc (vec, vec_offset + alloc * elt_size);
+ ((struct vec_prefix *)vec)->alloc = alloc;
+ if (!pfx)
+ ((struct vec_prefix *)vec)->num = 0;
+
+ return vec;
+}
+
+#if 0
+/* Example uses. */
+DEF_VEC_I (int);
+typedef struct X
+{
+ int i;
+} obj_t;
+typedef obj_t *ptr_t;
+
+DEF_VEC_P (ptr_t);
+DEF_VEC_O (obj_t);
+#endif