Add gnulib modules to replace missing libc functionality

This enables us to build a fully featured elfutils package on systems
with reduced C libraries, such as windows. All the modules are built
into libgnu.a, which is then linked into all binaries if
--enable-gnulib is given on the configure line.

Change-Id: I743fd22172bc85d9f10dcc3dad8eb921f462b554
Reviewed-by: Christian Kandeler <[email protected]>

1 files changed, 56 insertions, 0 deletions

diff --git a/libgnu/malloc.c b/libgnu/malloc.c
new file mode 100644
index 00000000..eeaf12ba
--- /dev/null
+++ b/libgnu/malloc.c
@@ -0,0 +1,56 @@
+/* malloc() function that is glibc compatible.
+
+   Copyright (C) 1997-1998, 2006-2007, 2009-2017 Free Software Foundation, Inc.
+
+   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, 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/>.  */
+
+/* written by Jim Meyering and Bruno Haible */
+
+#define _GL_USE_STDLIB_ALLOC 1
+#include <config.h>
+/* Only the AC_FUNC_MALLOC macro defines 'malloc' already in config.h.  */
+#ifdef malloc
+# define NEED_MALLOC_GNU 1
+# undef malloc
+/* Whereas the gnulib module 'malloc-gnu' defines HAVE_MALLOC_GNU.  */
+#elif GNULIB_MALLOC_GNU && !HAVE_MALLOC_GNU
+# define NEED_MALLOC_GNU 1
+#endif
+
+#include <stdlib.h>
+
+#include <errno.h>
+
+/* Allocate an N-byte block of memory from the heap.
+   If N is zero, allocate a 1-byte block.  */
+
+void *
+rpl_malloc (size_t n)
+{
+  void *result;
+
+#if NEED_MALLOC_GNU
+  if (n == 0)
+    n = 1;
+#endif
+
+  result = malloc (n);
+
+#if !HAVE_MALLOC_POSIX
+  if (result == NULL)
+    errno = ENOMEM;
+#endif
+
+  return result;
+}