Squashed 'third_party/elfutils/' content from commit 555e15e

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libelf/elf_newscn.c b/libelf/elf_newscn.c
new file mode 100644
index 0000000..d15a642
--- /dev/null
+++ b/libelf/elf_newscn.c
@@ -0,0 +1,162 @@
+/* Append new section.
+   Copyright (C) 1998,1999,2000,2001,2002,2005,2009,2014,2015 Red Hat, Inc.
+   This file is part of elfutils.
+   Written by Ulrich Drepper <drepper@redhat.com>, 1998.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libelfP.h"
+
+
+Elf_Scn *
+elf_newscn (Elf *elf)
+{
+  Elf_Scn *result = NULL;
+  bool first = false;
+
+  if (elf == NULL)
+    return NULL;
+
+  /* We rely on the prefix of the `elf', `elf32', and `elf64' element
+     being the same.  */
+  assert (offsetof (Elf, state.elf.scns_last)
+	  == offsetof (Elf, state.elf32.scns_last));
+  assert (offsetof (Elf, state.elf.scns_last)
+	  == offsetof (Elf, state.elf64.scns_last));
+  assert (offsetof (Elf, state.elf32.scns)
+	  == offsetof (Elf, state.elf64.scns));
+
+  rwlock_wrlock (elf->lock);
+
+ again:
+  if (elf->state.elf.scns_last->cnt < elf->state.elf.scns_last->max)
+    {
+      result = &elf->state.elf.scns_last->data[elf->state.elf.scns_last->cnt];
+
+      if (++elf->state.elf.scns_last->cnt == 1
+	  && (elf->state.elf.scns_last
+	      == (elf->class == ELFCLASS32
+		  || (offsetof (Elf, state.elf32.scns)
+		      == offsetof (Elf, state.elf64.scns))
+		  ? &elf->state.elf32.scns : &elf->state.elf64.scns)))
+	/* This is zeroth section.  */
+	first = true;
+      else
+	{
+	  assert (elf->state.elf.scns_last->cnt > 1);
+	  result->index = result[-1].index + 1;
+	}
+    }
+  else
+    {
+      /* We must allocate a new element.  */
+      Elf_ScnList *newp = NULL;
+
+      assert (elf->state.elf.scnincr > 0);
+
+      if (
+#if SIZE_MAX <= 4294967295U
+	  likely (elf->state.elf.scnincr
+		  < SIZE_MAX / 2 / sizeof (Elf_Scn) - sizeof (Elf_ScnList))
+#else
+	  1
+#endif
+	  )
+      newp = (Elf_ScnList *) calloc (sizeof (Elf_ScnList)
+				     + ((elf->state.elf.scnincr *= 2)
+					* sizeof (Elf_Scn)), 1);
+      if (newp == NULL)
+	{
+	  __libelf_seterrno (ELF_E_NOMEM);
+	  goto out;
+	}
+
+      result = &newp->data[0];
+
+      /* One section used.  */
+      ++newp->cnt;
+
+      /* This is the number of sections we allocated.  */
+      newp->max = elf->state.elf.scnincr;
+
+      /* Remember the index for the first section in this block.  */
+      newp->data[0].index
+	= 1 + elf->state.elf.scns_last->data[elf->state.elf.scns_last->max - 1].index;
+
+      /* Enqueue the new list element.  */
+      elf->state.elf.scns_last = elf->state.elf.scns_last->next = newp;
+    }
+
+  /* Create a section header for this section.  */
+  if (elf->class == ELFCLASS32)
+    {
+      result->shdr.e32 = (Elf32_Shdr *) calloc (1, sizeof (Elf32_Shdr));
+      if (result->shdr.e32 == NULL)
+	{
+	  __libelf_seterrno (ELF_E_NOMEM);
+	  goto out;
+	}
+    }
+  else
+    {
+      result->shdr.e64 = (Elf64_Shdr *) calloc (1, sizeof (Elf64_Shdr));
+      if (result->shdr.e64 == NULL)
+	{
+	  __libelf_seterrno (ELF_E_NOMEM);
+	  goto out;
+	}
+    }
+
+  result->elf = elf;
+  result->shdr_flags = ELF_F_DIRTY | ELF_F_MALLOCED;
+  result->list = elf->state.elf.scns_last;
+
+  /* Initialize the data part.  */
+  result->data_read = 1;
+  if (unlikely (first))
+    {
+      /* For the first section we mark the data as already available.  */
+      //result->data_list_rear = &result->data_list;
+      first = false;
+      goto again;
+    }
+
+  result->flags |= ELF_F_DIRTY;
+
+ out:
+  rwlock_unlock (elf->lock);
+
+  return result;
+}