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, 142 insertions, 0 deletions

diff --git a/REORG.TODO/stdlib/abort.c b/REORG.TODO/stdlib/abort.c
new file mode 100644
index 0000000000..19882f3e3d
--- /dev/null
+++ b/REORG.TODO/stdlib/abort.c
@@ -0,0 +1,142 @@
+/* Copyright (C) 1991-2017 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 <libc-lock.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sigsetops.h>
+
+/* Try to get a machine dependent instruction which will make the
+   program crash.  This is used in case everything else fails.  */
+#include <abort-instr.h>
+#ifndef ABORT_INSTRUCTION
+/* No such instruction is available.  */
+# define ABORT_INSTRUCTION
+#endif
+
+#include <libio/libioP.h>
+#define fflush(s) _IO_flush_all_lockp (0)
+
+/* Exported variable to locate abort message in core files etc.  */
+struct abort_msg_s *__abort_msg __attribute__ ((nocommon));
+libc_hidden_def (__abort_msg)
+
+/* We must avoid to run in circles.  Therefore we remember how far we
+   already got.  */
+static int stage;
+
+/* We should be prepared for multiple threads trying to run abort.  */
+__libc_lock_define_initialized_recursive (static, lock);
+
+
+/* Cause an abnormal program termination with core-dump.  */
+void
+abort (void)
+{
+  struct sigaction act;
+  sigset_t sigs;
+
+  /* First acquire the lock.  */
+  __libc_lock_lock_recursive (lock);
+
+  /* Now it's for sure we are alone.  But recursive calls are possible.  */
+
+  /* Unblock SIGABRT.  */
+  if (stage == 0)
+    {
+      ++stage;
+      __sigemptyset (&sigs);
+      __sigaddset (&sigs, SIGABRT);
+      __sigprocmask (SIG_UNBLOCK, &sigs, 0);
+    }
+
+  /* Flush all streams.  We cannot close them now because the user
+     might have registered a handler for SIGABRT.  */
+  if (stage == 1)
+    {
+      ++stage;
+      fflush (NULL);
+    }
+
+  /* Send signal which possibly calls a user handler.  */
+  if (stage == 2)
+    {
+      /* This stage is special: we must allow repeated calls of
+	 `abort' when a user defined handler for SIGABRT is installed.
+	 This is risky since the `raise' implementation might also
+	 fail but I don't see another possibility.  */
+      int save_stage = stage;
+
+      stage = 0;
+      __libc_lock_unlock_recursive (lock);
+
+      raise (SIGABRT);
+
+      __libc_lock_lock_recursive (lock);
+      stage = save_stage + 1;
+    }
+
+  /* There was a handler installed.  Now remove it.  */
+  if (stage == 3)
+    {
+      ++stage;
+      memset (&act, '\0', sizeof (struct sigaction));
+      act.sa_handler = SIG_DFL;
+      __sigfillset (&act.sa_mask);
+      act.sa_flags = 0;
+      __sigaction (SIGABRT, &act, NULL);
+    }
+
+  /* Now close the streams which also flushes the output the user
+     defined handler might has produced.  */
+  if (stage == 4)
+    {
+      ++stage;
+      __fcloseall ();
+    }
+
+  /* Try again.  */
+  if (stage == 5)
+    {
+      ++stage;
+      raise (SIGABRT);
+    }
+
+  /* Now try to abort using the system specific command.  */
+  if (stage == 6)
+    {
+      ++stage;
+      ABORT_INSTRUCTION;
+    }
+
+  /* If we can't signal ourselves and the abort instruction failed, exit.  */
+  if (stage == 7)
+    {
+      ++stage;
+      _exit (127);
+    }
+
+  /* If even this fails try to use the provided instruction to crash
+     or otherwise make sure we never return.  */
+  while (1)
+    /* Try for ever and ever.  */
+    ABORT_INSTRUCTION;
+}
+libc_hidden_def (abort)