Import readline 7.0 (patch 5)

This imports readline 7.0 (up to patch 5) while preserving all
gdb-local changes.

This was done by checking out the readline git repository, making a
branch based on the gdb baseline revision, applying the gdb changes to
that branch, and then merging from readline 7.

readline/ChangeLog.gdb
2019-08-12  Tom Tromey  <tom@tromey.com>

	* Imported readline 7.0 patch 5.

1 files changed, 112 insertions, 45 deletions

diff --git a/readline/signals.c b/readline/signals.c
index f119691..927f532 100644
--- a/readline/signals.c
+++ b/readline/signals.c
@@ -1,6 +1,6 @@
 /* signals.c -- signal handling support for readline. */
 
-/* Copyright (C) 1987-2009 Free Software Foundation, Inc.
+/* Copyright (C) 1987-2016 Free Software Foundation, Inc.
 
    This file is part of the GNU Readline Library (Readline), a library
    for reading lines of text with interactive input and history editing.      
@@ -80,6 +80,7 @@ typedef struct { SigHandler *sa_handler; int sa_mask, sa_flags; } sighandler_cxt
 
 static SigHandler *rl_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *));
 static void rl_maybe_set_sighandler PARAMS((int, SigHandler *, sighandler_cxt *));
+static void rl_maybe_restore_sighandler PARAMS((int, sighandler_cxt *));
 
 static RETSIGTYPE rl_signal_handler PARAMS((int));
 static RETSIGTYPE _rl_handle_signal PARAMS((int));
@@ -87,7 +88,7 @@ static RETSIGTYPE _rl_handle_signal PARAMS((int));
 /* Exported variables for use by applications. */
 
 /* If non-zero, readline will install its own signal handlers for
-   SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP, SIGTTIN, and SIGTTOU. */
+   SIGINT, SIGTERM, SIGHUP, SIGQUIT, SIGALRM, SIGTSTP, SIGTTIN, and SIGTTOU. */
 int rl_catch_signals = 1;
 
 /* If non-zero, readline will install a signal handler for SIGWINCH. */
@@ -118,7 +119,7 @@ static int sigwinch_set_flag;
 /*								    */
 /* **************************************************************** */
 
-static sighandler_cxt old_int, old_term, old_alrm, old_quit;
+static sighandler_cxt old_int, old_term, old_hup, old_alrm, old_quit;
 #if defined (SIGTSTP)
 static sighandler_cxt old_tstp, old_ttou, old_ttin;
 #endif
@@ -126,6 +127,9 @@ static sighandler_cxt old_tstp, old_ttou, old_ttin;
 static sighandler_cxt old_winch;
 #endif
 
+_rl_sigcleanup_func_t *_rl_sigcleanup;
+void *_rl_sigcleanarg;
+
 /* Readline signal handler functions. */
 
 /* Called from RL_CHECK_SIGNALS() macro */
@@ -135,7 +139,21 @@ _rl_signal_handler (sig)
 {
   _rl_caught_signal = 0;	/* XXX */
 
-  _rl_handle_signal (sig);
+#if defined (SIGWINCH)
+  if (sig == SIGWINCH)
+    {
+      rl_resize_terminal ();
+      /* XXX - experimental for now */
+      /* Call a signal hook because though we called the original signal handler
+	 in rl_sigwinch_handler below, we will not resend the signal to
+	 ourselves. */
+      if (rl_signal_event_hook)
+	(*rl_signal_event_hook) ();
+    }
+  else
+#endif
+    _rl_handle_signal (sig);
+
   SIGHANDLER_RETURN;
 }
 
@@ -143,7 +161,7 @@ static RETSIGTYPE
 rl_signal_handler (sig)
      int sig;
 {
-  if (_rl_interrupt_immediately || RL_ISSTATE(RL_STATE_CALLBACK))
+  if (_rl_interrupt_immediately)
     {
       _rl_interrupt_immediately = 0;
       _rl_handle_signal (sig);
@@ -181,19 +199,45 @@ _rl_handle_signal (sig)
     rl_set_sighandler (sig, SIG_IGN, &dummy_cxt);
 #endif /* !HAVE_BSD_SIGNALS && !HAVE_POSIX_SIGNALS */
 
+  /* If there's a sig cleanup function registered, call it and `deregister'
+     the cleanup function to avoid multiple calls */
+  if (_rl_sigcleanup)
+    {
+      (*_rl_sigcleanup) (sig, _rl_sigcleanarg);
+      _rl_sigcleanup = 0;
+      _rl_sigcleanarg = 0;
+    }
+    
   switch (sig)
     {
     case SIGINT:
       _rl_reset_completion_state ();
       rl_free_line_state ();
+#if defined (READLINE_CALLBACKS)
+      rl_callback_sigcleanup ();
+#endif
+
       /* FALLTHROUGH */
 
-    case SIGTERM:
 #if defined (SIGTSTP)
     case SIGTSTP:
-    case SIGTTOU:
     case SIGTTIN:
+#  if defined (HAVE_POSIX_SIGNALS)
+      /* Block SIGTTOU so we can restore the terminal settings to something
+	 sane without stopping on SIGTTOU if we have been placed into the
+	 background.  Even trying to get the current terminal pgrp with
+	 tcgetpgrp() will generate SIGTTOU, so we don't bother.  Don't bother
+	 doing this if we've been stopped on SIGTTOU; it's aready too late. */
+      sigemptyset (&set);
+      sigaddset (&set, SIGTTOU);
+      sigprocmask (SIG_BLOCK, &set, (sigset_t *)NULL);
+#  endif
+    case SIGTTOU:
 #endif /* SIGTSTP */
+    case SIGTERM:
+#if defined (SIGHUP)
+    case SIGHUP:
+#endif
 #if defined (SIGALRM)
     case SIGALRM:
 #endif
@@ -204,6 +248,10 @@ _rl_handle_signal (sig)
       rl_cleanup_after_signal ();
 
 #if defined (HAVE_POSIX_SIGNALS)
+      /* Unblock SIGTTOU blocked above */
+      if (sig == SIGTTIN || sig == SIGTSTP)
+	sigprocmask (SIG_UNBLOCK, &set, (sigset_t *)NULL);
+
       sigemptyset (&set);
       sigprocmask (SIG_BLOCK, (sigset_t *)NULL, &set);
       sigdelset (&set, sig);
@@ -232,7 +280,7 @@ _rl_handle_signal (sig)
 #  endif /* HAVE_BSD_SIGNALS */
 #endif /* !HAVE_POSIX_SIGNALS */
 
-      rl_reset_after_signal ();
+      rl_reset_after_signal ();      
     }
 
   RL_UNSETSTATE(RL_STATE_SIGHANDLER);
@@ -257,7 +305,7 @@ rl_sigwinch_handler (sig)
 #endif
 
   RL_SETSTATE(RL_STATE_SIGHANDLER);
-  rl_resize_terminal ();
+  _rl_caught_signal = sig;
 
   /* If another sigwinch handler has been installed, call it. */
   oh = (SigHandler *)old_winch.sa_handler;
@@ -317,6 +365,8 @@ rl_set_sighandler (sig, handler, ohandler)
   return (ohandler->sa_handler);
 }
 
+/* Set disposition of SIG to HANDLER, returning old state in OHANDLER.  Don't
+   change disposition if OHANDLER indicates the signal was ignored. */
 static void
 rl_maybe_set_sighandler (sig, handler, ohandler)
      int sig;
@@ -327,11 +377,29 @@ rl_maybe_set_sighandler (sig, handler, ohandler)
   SigHandler *oh;
 
   sigemptyset (&dummy.sa_mask);
+  dummy.sa_flags = 0;
   oh = rl_set_sighandler (sig, handler, ohandler);
   if (oh == (SigHandler *)SIG_IGN)
     rl_sigaction (sig, ohandler, &dummy);
 }
 
+/* Set the disposition of SIG to HANDLER, if HANDLER->sa_handler indicates the
+   signal was not being ignored.  MUST only be called for signals whose
+   disposition was changed using rl_maybe_set_sighandler or for which the
+   SIG_IGN check was performed inline (e.g., SIGALRM below). */
+static void
+rl_maybe_restore_sighandler (sig, handler)
+     int sig;
+     sighandler_cxt *handler;
+{
+  sighandler_cxt dummy;
+
+  sigemptyset (&dummy.sa_mask);
+  dummy.sa_flags = 0;
+  if (handler->sa_handler != SIG_IGN)
+    rl_sigaction (sig, handler, &dummy);
+}
+
 int
 rl_set_signals ()
 {
@@ -349,6 +417,9 @@ rl_set_signals ()
 
       sigaddset (&bset, SIGINT);
       sigaddset (&bset, SIGTERM);
+#if defined (SIGHUP)
+      sigaddset (&bset, SIGHUP);
+#endif
 #if defined (SIGQUIT)
       sigaddset (&bset, SIGQUIT);
 #endif
@@ -377,6 +448,9 @@ rl_set_signals ()
 
       rl_maybe_set_sighandler (SIGINT, rl_signal_handler, &old_int);
       rl_maybe_set_sighandler (SIGTERM, rl_signal_handler, &old_term);
+#if defined (SIGHUP)
+      rl_maybe_set_sighandler (SIGHUP, rl_signal_handler, &old_hup);
+#endif
 #if defined (SIGQUIT)
       rl_maybe_set_sighandler (SIGQUIT, rl_signal_handler, &old_quit);
 #endif
@@ -434,25 +508,33 @@ rl_clear_signals ()
     {
       sigemptyset (&dummy.sa_mask);
 
-      rl_sigaction (SIGINT, &old_int, &dummy);
-      rl_sigaction (SIGTERM, &old_term, &dummy);
+      /* Since rl_maybe_set_sighandler doesn't override a SIG_IGN handler,
+	 we should in theory not have to restore a handler where
+	 old_xxx.sa_handler == SIG_IGN.  That's what rl_maybe_restore_sighandler
+	 does.  Fewer system calls should reduce readline's per-line
+	 overhead */
+      rl_maybe_restore_sighandler (SIGINT, &old_int);
+      rl_maybe_restore_sighandler (SIGTERM, &old_term);
+#if defined (SIGHUP)
+      rl_maybe_restore_sighandler (SIGHUP, &old_hup);
+#endif
 #if defined (SIGQUIT)
-      rl_sigaction (SIGQUIT, &old_quit, &dummy);
+      rl_maybe_restore_sighandler (SIGQUIT, &old_quit);
 #endif
 #if defined (SIGALRM)
-      rl_sigaction (SIGALRM, &old_alrm, &dummy);
+      rl_maybe_restore_sighandler (SIGALRM, &old_alrm);
 #endif
 
 #if defined (SIGTSTP)
-      rl_sigaction (SIGTSTP, &old_tstp, &dummy);
+      rl_maybe_restore_sighandler (SIGTSTP, &old_tstp);
 #endif /* SIGTSTP */
 
 #if defined (SIGTTOU)
-      rl_sigaction (SIGTTOU, &old_ttou, &dummy);
+      rl_maybe_restore_sighandler (SIGTTOU, &old_ttou);
 #endif /* SIGTTOU */
 
 #if defined (SIGTTIN)
-      rl_sigaction (SIGTTIN, &old_ttin, &dummy);
+      rl_maybe_restore_sighandler (SIGTTIN, &old_ttin);
 #endif /* SIGTTIN */
 
       signals_set_flag = 0;
@@ -511,6 +593,11 @@ rl_free_line_state ()
   _rl_reset_argument ();
 }
 
+int
+rl_pending_signal ()
+{
+  return (_rl_caught_signal);
+}
 #endif  /* HANDLE_SIGNALS */
 
 /* **************************************************************** */
@@ -540,21 +627,6 @@ _rl_block_sigint ()
   if (sigint_blocked)
     return;
 
-#if defined (HAVE_POSIX_SIGNALS)
-  sigemptyset (&sigint_set);
-  sigemptyset (&sigint_oset);
-  sigaddset (&sigint_set, SIGINT);
-  sigprocmask (SIG_BLOCK, &sigint_set, &sigint_oset);
-#else /* !HAVE_POSIX_SIGNALS */
-#  if defined (HAVE_BSD_SIGNALS)
-  sigint_oldmask = sigblock (sigmask (SIGINT));
-#  else /* !HAVE_BSD_SIGNALS */
-#    if defined (HAVE_USG_SIGHOLD)
-  sighold (SIGINT);
-#    endif /* HAVE_USG_SIGHOLD */
-#  endif /* !HAVE_BSD_SIGNALS */
-#endif /* !HAVE_POSIX_SIGNALS */
-
   sigint_blocked = 1;
 }
 
@@ -565,22 +637,10 @@ _rl_release_sigint ()
   if (sigint_blocked == 0)
     return;
 
-#if defined (HAVE_POSIX_SIGNALS)
-  sigprocmask (SIG_SETMASK, &sigint_oset, (sigset_t *)NULL);
-#else
-#  if defined (HAVE_BSD_SIGNALS)
-  sigsetmask (sigint_oldmask);
-#  else /* !HAVE_BSD_SIGNALS */
-#    if defined (HAVE_USG_SIGHOLD)
-  sigrelse (SIGINT);
-#    endif /* HAVE_USG_SIGHOLD */
-#  endif /* !HAVE_BSD_SIGNALS */
-#endif /* !HAVE_POSIX_SIGNALS */
-
   sigint_blocked = 0;
+  RL_CHECK_SIGNALS ();
 }
 
-#ifdef SIGWINCH
 /* Cause SIGWINCH to not be delivered until the corresponding call to
    release_sigwinch(). */
 void
@@ -589,6 +649,8 @@ _rl_block_sigwinch ()
   if (sigwinch_blocked)
     return;
 
+#if defined (SIGWINCH)
+
 #if defined (HAVE_POSIX_SIGNALS)
   sigemptyset (&sigwinch_set);
   sigemptyset (&sigwinch_oset);
@@ -604,6 +666,8 @@ _rl_block_sigwinch ()
 #  endif /* !HAVE_BSD_SIGNALS */
 #endif /* !HAVE_POSIX_SIGNALS */
 
+#endif /* SIGWINCH */
+
   sigwinch_blocked = 1;
 }
 
@@ -614,6 +678,8 @@ _rl_release_sigwinch ()
   if (sigwinch_blocked == 0)
     return;
 
+#if defined (SIGWINCH)
+
 #if defined (HAVE_POSIX_SIGNALS)
   sigprocmask (SIG_SETMASK, &sigwinch_oset, (sigset_t *)NULL);
 #else
@@ -626,9 +692,10 @@ _rl_release_sigwinch ()
 #  endif /* !HAVE_BSD_SIGNALS */
 #endif /* !HAVE_POSIX_SIGNALS */
 
+#endif /* SIGWINCH */
+
   sigwinch_blocked = 0;
 }
-#endif /* SIGWINCH */
 
 /* **************************************************************** */
 /*								    */