Update Gnulib to the latest git version

[thirdparty/binutils-gdb.git] / gnulib / import / malloc / scratch_buffer_grow_preserve.c

diff --git a/gnulib/import/malloc/scratch_buffer_grow_preserve.c b/gnulib/import/malloc/scratch_buffer_grow_preserve.c
new file mode 100644 (file)
index 0000000..4da8fc1
--- /dev/null
+++ b/gnulib/import/malloc/scratch_buffer_grow_preserve.c
@@ -0,0 +1,67 @@
+/* Variable-sized buffer with on-stack default allocation.
+   Copyright (C) 2015-2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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.
+
+   The GNU C Library 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 the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _LIBC
+# include <libc-config.h>
+#endif
+
+#include <scratch_buffer.h>
+#include <errno.h>
+#include <string.h>
+
+bool
+__libc_scratch_buffer_grow_preserve (struct scratch_buffer *buffer)
+{
+  size_t new_length = 2 * buffer->length;
+  void *new_ptr;
+
+  if (buffer->data == buffer->__space.__c)
+    {
+      /* Move buffer to the heap.  No overflow is possible because
+        buffer->length describes a small buffer on the stack.  */
+      new_ptr = malloc (new_length);
+      if (new_ptr == NULL)
+       return false;
+      memcpy (new_ptr, buffer->__space.__c, buffer->length);
+    }
+  else
+    {
+      /* Buffer was already on the heap.  Check for overflow.  */
+      if (__glibc_likely (new_length >= buffer->length))
+       new_ptr = realloc (buffer->data, new_length);
+      else
+       {
+         __set_errno (ENOMEM);
+         new_ptr = NULL;
+       }
+
+      if (__glibc_unlikely (new_ptr == NULL))
+       {
+         /* Deallocate, but buffer must remain valid to free.  */
+         free (buffer->data);
+         scratch_buffer_init (buffer);
+         return false;
+       }
+    }
+
+  /* Install new heap-based buffer.  */
+  buffer->data = new_ptr;
+  buffer->length = new_length;
+  return true;
+}
+libc_hidden_def (__libc_scratch_buffer_grow_preserve)