1 files changed, 123 insertions, 0 deletions
diff --git a/sysdeps/nacl/nacl-interfaces.c b/sysdeps/nacl/nacl-interfaces.c
new file mode 100644
index 0000000000..cb0dcd0bc8
--- /dev/null
+++ b/sysdeps/nacl/nacl-interfaces.c
@@ -0,0 +1,123 @@
+/* Using NaCl interface tables.
+   Copyright (C) 2015 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 Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <nacl-interfaces.h>
+#include <ldsodefs.h>
+
+
+/* These magic symbols are provided implicitly by the linker to
+   give us the bounds of the specially-named sections.  */
+
+extern const struct nacl_interface __start_nacl_mandatory_interface_names[]
+  attribute_hidden;
+extern const struct nacl_interface __stop_nacl_mandatory_interface_names[]
+  attribute_hidden;
+
+extern uintptr_t __start_nacl_mandatory_interface_tables[]
+  attribute_hidden;
+extern uintptr_t __stop_nacl_mandatory_interface_tables[]
+  attribute_hidden;
+
+/* We use weak references for the optional ones, since they
+   might not be included at all in any given statically-linked program.  */
+
+extern const struct nacl_interface __start_nacl_optional_interface_names[]
+  attribute_hidden __attribute__ ((weak));
+extern const struct nacl_interface __stop_nacl_optional_interface_names[]
+  attribute_hidden __attribute__ ((weak));
+
+extern uintptr_t __start_nacl_optional_interface_tables[]
+  attribute_hidden __attribute__ ((weak));
+extern uintptr_t __stop_nacl_optional_interface_tables[]
+  attribute_hidden __attribute__ ((weak));
+
+static uintptr_t *
+next_nacl_table (uintptr_t *t, const struct nacl_interface *i)
+{
+  return (void *) t + i->table_size;
+}
+
+static void __attribute__ ((noreturn))
+missing_mandatory_interface (const struct nacl_interface *i)
+{
+  static const char before[] =
+    "FATAL: NaCl IRT interface query failed for essential interface \"";
+  static const char after[] =
+    "\"\n";
+
+  if (__nacl_irt_fdio.write != NULL)
+    {
+      size_t wrote;
+      (*__nacl_irt_fdio.write) (2, before, sizeof before - 1, &wrote);
+      (*__nacl_irt_fdio.write) (2, i->name, i->namelen - 1, &wrote);
+      (*__nacl_irt_fdio.write) (2, after, sizeof after - 1, &wrote);
+    }
+
+  if (__nacl_irt_basic.exit != NULL)
+    (*__nacl_irt_basic.exit) (-1);
+
+  __builtin_trap ();
+}
+
+static void
+initialize_mandatory_interfaces (void)
+{
+  const struct nacl_interface *i = __start_nacl_mandatory_interface_names;
+  uintptr_t *t = __start_nacl_mandatory_interface_tables;
+  while (i < __stop_nacl_mandatory_interface_names)
+    {
+      if (__nacl_irt_query (i->name, t, i->table_size) != i->table_size)
+	missing_mandatory_interface (i);
+
+      t = next_nacl_table (t, i);
+      i = next_nacl_interface (i);
+    }
+}
+
+
+static int
+nacl_missing_optional_interface (void)
+{
+  return ENOSYS;
+}
+
+static void
+initialize_optional_interfaces (void)
+{
+  const struct nacl_interface *i = __start_nacl_optional_interface_names;
+  uintptr_t *t = __start_nacl_optional_interface_tables;
+  while (i < __stop_nacl_optional_interface_names)
+    {
+      size_t filled = __nacl_irt_query (i->name, t, i->table_size);
+      if (filled != i->table_size)
+	for (size_t slot = 0; slot < i->table_size / sizeof *t; ++slot)
+	  t[slot] = (uintptr_t) &nacl_missing_optional_interface;
+
+      t = next_nacl_table (t, i);
+      i = next_nacl_interface (i);
+    }
+}
+
+
+void attribute_hidden
+__nacl_initialize_interfaces (void)
+{
+  initialize_mandatory_interfaces ();
+  initialize_optional_interfaces ();
+}