Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 254 insertions, 0 deletions

diff --git a/REORG.TODO/dlfcn/dlerror.c b/REORG.TODO/dlfcn/dlerror.c
new file mode 100644
index 0000000000..c0ead7dcb6
--- /dev/null
+++ b/REORG.TODO/dlfcn/dlerror.c
@@ -0,0 +1,254 @@
+/* Return error detail for failing <dlfcn.h> functions.
+   Copyright (C) 1995-2017 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 <dlfcn.h>
+#include <libintl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <libc-lock.h>
+#include <ldsodefs.h>
+
+#if !defined SHARED && IS_IN (libdl)
+
+char *
+dlerror (void)
+{
+  return __dlerror ();
+}
+
+#else
+
+/* Type for storing results of dynamic loading actions.  */
+struct dl_action_result
+  {
+    int errcode;
+    int returned;
+    bool malloced;
+    const char *objname;
+    const char *errstring;
+  };
+static struct dl_action_result last_result;
+static struct dl_action_result *static_buf;
+
+/* This is the key for the thread specific memory.  */
+static __libc_key_t key;
+__libc_once_define (static, once);
+
+/* Destructor for the thread-specific data.  */
+static void init (void);
+static void free_key_mem (void *mem);
+
+
+char *
+__dlerror (void)
+{
+  char *buf = NULL;
+  struct dl_action_result *result;
+
+# ifdef SHARED
+  if (__glibc_unlikely (_dlfcn_hook != NULL))
+    return _dlfcn_hook->dlerror ();
+# endif
+
+  /* If we have not yet initialized the buffer do it now.  */
+  __libc_once (once, init);
+
+  /* Get error string.  */
+  result = (struct dl_action_result *) __libc_getspecific (key);
+  if (result == NULL)
+    result = &last_result;
+
+  /* Test whether we already returned the string.  */
+  if (result->returned != 0)
+    {
+      /* We can now free the string.  */
+      if (result->errstring != NULL)
+	{
+	  if (strcmp (result->errstring, "out of memory") != 0)
+	    free ((char *) result->errstring);
+	  result->errstring = NULL;
+	}
+    }
+  else if (result->errstring != NULL)
+    {
+      buf = (char *) result->errstring;
+      int n;
+      if (result->errcode == 0)
+	n = __asprintf (&buf, "%s%s%s",
+			result->objname,
+			result->objname[0] == '\0' ? "" : ": ",
+			_(result->errstring));
+      else
+	n = __asprintf (&buf, "%s%s%s: %s",
+			result->objname,
+			result->objname[0] == '\0' ? "" : ": ",
+			_(result->errstring),
+			strerror (result->errcode));
+      if (n != -1)
+	{
+	  /* We don't need the error string anymore.  */
+	  if (strcmp (result->errstring, "out of memory") != 0)
+	    free ((char *) result->errstring);
+	  result->errstring = buf;
+	}
+
+      /* Mark the error as returned.  */
+      result->returned = 1;
+    }
+
+  return buf;
+}
+# ifdef SHARED
+strong_alias (__dlerror, dlerror)
+# endif
+
+int
+internal_function
+_dlerror_run (void (*operate) (void *), void *args)
+{
+  struct dl_action_result *result;
+
+  /* If we have not yet initialized the buffer do it now.  */
+  __libc_once (once, init);
+
+  /* Get error string and number.  */
+  if (static_buf != NULL)
+    result = static_buf;
+  else
+    {
+      /* We don't use the static buffer and so we have a key.  Use it
+	 to get the thread-specific buffer.  */
+      result = __libc_getspecific (key);
+      if (result == NULL)
+	{
+	  result = (struct dl_action_result *) calloc (1, sizeof (*result));
+	  if (result == NULL)
+	    /* We are out of memory.  Since this is no really critical
+	       situation we carry on by using the global variable.
+	       This might lead to conflicts between the threads but
+	       they soon all will have memory problems.  */
+	    result = &last_result;
+	  else
+	    /* Set the tsd.  */
+	    __libc_setspecific (key, result);
+	}
+    }
+
+  if (result->errstring != NULL)
+    {
+      /* Free the error string from the last failed command.  This can
+	 happen if `dlerror' was not run after an error was found.  */
+      if (result->malloced)
+	free ((char *) result->errstring);
+      result->errstring = NULL;
+    }
+
+  result->errcode = _dl_catch_error (&result->objname, &result->errstring,
+				     &result->malloced, operate, args);
+
+  /* If no error we mark that no error string is available.  */
+  result->returned = result->errstring == NULL;
+
+  return result->errstring != NULL;
+}
+
+
+/* Initialize buffers for results.  */
+static void
+init (void)
+{
+  if (__libc_key_create (&key, free_key_mem))
+    /* Creating the key failed.  This means something really went
+       wrong.  In any case use a static buffer which is better than
+       nothing.  */
+    static_buf = &last_result;
+}
+
+
+static void
+check_free (struct dl_action_result *rec)
+{
+  if (rec->errstring != NULL
+      && strcmp (rec->errstring, "out of memory") != 0)
+    {
+      /* We can free the string only if the allocation happened in the
+	 C library used by the dynamic linker.  This means, it is
+	 always the C library in the base namespace.  When we're statically
+         linked, the dynamic linker is part of the program and so always
+	 uses the same C library we use here.  */
+#ifdef SHARED
+      struct link_map *map = NULL;
+      Dl_info info;
+      if (_dl_addr (check_free, &info, &map, NULL) != 0 && map->l_ns == 0)
+#endif
+	free ((char *) rec->errstring);
+    }
+}
+
+
+static void
+__attribute__ ((destructor))
+fini (void)
+{
+  check_free (&last_result);
+}
+
+
+/* Free the thread specific data, this is done if a thread terminates.  */
+static void
+free_key_mem (void *mem)
+{
+  check_free ((struct dl_action_result *) mem);
+
+  free (mem);
+  __libc_setspecific (key, NULL);
+}
+
+# ifdef SHARED
+
+struct dlfcn_hook *_dlfcn_hook __attribute__((nocommon));
+libdl_hidden_data_def (_dlfcn_hook)
+
+# else
+
+static struct dlfcn_hook _dlfcn_hooks =
+  {
+    .dlopen = __dlopen,
+    .dlclose = __dlclose,
+    .dlsym = __dlsym,
+    .dlvsym = __dlvsym,
+    .dlerror = __dlerror,
+    .dladdr = __dladdr,
+    .dladdr1 = __dladdr1,
+    .dlinfo = __dlinfo,
+    .dlmopen = __dlmopen
+  };
+
+void
+__libc_register_dlfcn_hook (struct link_map *map)
+{
+  struct dlfcn_hook **hook;
+
+  hook = (struct dlfcn_hook **) __libc_dlsym_private (map, "_dlfcn_hook");
+  if (hook != NULL)
+    *hook = &_dlfcn_hooks;
+}
+# endif
+#endif