Move gdb's xmalloc and friends to new file

When "common" becomes a library, linking will cause a symbol clash,
because "xmalloc" and some related symbols are defined in that
library, libiberty, and readline.

To work around this problem, this patch moves the clashing symbols to
a new file, which is then compiled separately for both gdb and
gdbserver.

gdb/ChangeLog
2019-06-11  Tom Tromey  <tom@tromey.com>

	* common/common-utils.c (xmalloc, xrealloc, xcalloc)
	(xmalloc_failed): Move to alloc.c.
	* alloc.c: New file.
	* Makefile.in (COMMON_SFILES): Add alloc.c.

gdb/gdbserver/ChangeLog
2019-06-11  Tom Tromey  <tom@tromey.com>

	* Makefile.in (SFILES): Add alloc.c.
	(OBS): Add alloc.o.
	(IPA_OBJS): Add alloc-ipa.o.
	(alloc-ipa.o): New target.
	(%.o: ../%.c): New pattern rule.

1 files changed, 111 insertions, 0 deletions

diff --git a/gdb/alloc.c b/gdb/alloc.c
new file mode 100644
index 00000000000..95488a72cf2
--- /dev/null
+++ b/gdb/alloc.c
@@ -0,0 +1,111 @@
+/* Shared allocation functions for GDB, the GNU debugger.
+
+   Copyright (C) 1986-2019 Free Software Foundation, Inc.
+
+   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/>.  */
+
+/* This file is unusual.
+
+   Because both libiberty and readline define xmalloc and friends, the
+   functions in this file can't appear in a library -- that will cause
+   link errors.
+
+   And, because we want to turn the common code into a library, this
+   file can't live there.
+
+   So, it lives in gdb and is built separately by gdb and gdbserver.
+   Please be aware of this when modifying it.
+
+   This also explains why this file includes common-defs.h and not
+   defs.h or server.h -- we'd prefer to avoid depending on the
+   GDBSERVER define when possible, and for this file it seemed
+   simple to do so.  */
+
+#include "common/common-defs.h"
+#include "libiberty.h"
+#include "common/errors.h"
+
+/* The xmalloc() (libiberty.h) family of memory management routines.
+
+   These are like the ISO-C malloc() family except that they implement
+   consistent semantics and guard against typical memory management
+   problems.  */
+
+/* NOTE: These are declared using PTR to ensure consistency with
+   "libiberty.h".  xfree() is GDB local.  */
+
+PTR                            /* ARI: PTR */
+xmalloc (size_t size)
+{
+  void *val;
+
+  /* See libiberty/xmalloc.c.  This function need's to match that's
+     semantics.  It never returns NULL.  */
+  if (size == 0)
+    size = 1;
+
+  val = malloc (size);         /* ARI: malloc */
+  if (val == NULL)
+    malloc_failure (size);
+
+  return val;
+}
+
+PTR                              /* ARI: PTR */
+xrealloc (PTR ptr, size_t size)          /* ARI: PTR */
+{
+  void *val;
+
+  /* See libiberty/xmalloc.c.  This function need's to match that's
+     semantics.  It never returns NULL.  */
+  if (size == 0)
+    size = 1;
+
+  if (ptr != NULL)
+    val = realloc (ptr, size);	/* ARI: realloc */
+  else
+    val = malloc (size);	        /* ARI: malloc */
+  if (val == NULL)
+    malloc_failure (size);
+
+  return val;
+}
+
+PTR                            /* ARI: PTR */
+xcalloc (size_t number, size_t size)
+{
+  void *mem;
+
+  /* See libiberty/xmalloc.c.  This function need's to match that's
+     semantics.  It never returns NULL.  */
+  if (number == 0 || size == 0)
+    {
+      number = 1;
+      size = 1;
+    }
+
+  mem = calloc (number, size);      /* ARI: xcalloc */
+  if (mem == NULL)
+    malloc_failure (number * size);
+
+  return mem;
+}
+
+void
+xmalloc_failed (size_t size)
+{
+  malloc_failure (size);
+}