* main.c, utils.c: Add comments about immediate_quit.

diff --git a/gdb/utils.c b/gdb/utils.c
index 099a72e944a694c826ae08b60cc3abb52aca4101..14a5c79d895aa5914f244790a762cb515c4a1a22 100644 (file)
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -29,7 +29,11 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 #include "signals.h"
 #include "gdbcmd.h"
 
 #include "signals.h"
 #include "gdbcmd.h"

+#include "serial.h"
+#if 0
+/* No longer needed, I suspect.  */

 #include "terminal.h"
 #include "terminal.h"

+#endif

 #include "bfd.h"
 #include "target.h"
 #include "demangle.h"
 #include "bfd.h"
 #include "target.h"
 #include "demangle.h"


@@ -70,8 +74,16 @@ static struct cleanup *cleanup_chain;
 
 int quit_flag;
 
 
 int quit_flag;
 

-/* Nonzero means quit immediately if Control-C is typed now,
-   rather than waiting until QUIT is executed.  */
+/* Nonzero means quit immediately if Control-C is typed now, rather
+   than waiting until QUIT is executed.  Be careful in setting this;
+   code which executes with immediate_quit set has to be very careful
+   about being able to deal with being interrupted at any time.  It is
+   almost always better to use QUIT; the only exception I can think of
+   is being able to quit out of a system call (using EINTR loses if
+   the SIGINT happens between the previous QUIT and the system call).
+   To immediately quit in the case in which a SIGINT happens between
+   the previous QUIT and setting immediate_quit (desirable anytime we
+   expect to block), call QUIT after setting immediate_quit.  */

 
 int immediate_quit;
 
 
 int immediate_quit;
 


@@ -258,7 +270,7 @@ error (va_alist)
   vfprintf_filtered (stderr, string, args);
   fprintf_filtered (stderr, "\n");
   va_end (args);
   vfprintf_filtered (stderr, string, args);
   fprintf_filtered (stderr, "\n");
   va_end (args);

-  return_to_top_level ();
+  return_to_top_level (RETURN_ERROR);

 }
 
 /* Print an error message and exit reporting failure.
 }
 
 /* Print an error message and exit reporting failure.


@@ -401,22 +413,28 @@ print_sys_errmsg (string, errcode)
 void
 quit ()
 {
 void
 quit ()
 {

+  serial_t stdout_serial = serial_fdopen (1);
+

   target_terminal_ours ();
   wrap_here ((char *)0);               /* Force out any pending output */
   target_terminal_ours ();
   wrap_here ((char *)0);               /* Force out any pending output */

-#if !defined(__GO32__)
-#ifdef HAVE_TERMIO
-  ioctl (fileno (stdout), TCFLSH, 1);
-#else /* not HAVE_TERMIO */
-  ioctl (fileno (stdout), TIOCFLUSH, 0);
-#endif /* not HAVE_TERMIO */
-#ifdef TIOCGPGRP
-  error ("Quit");
-#else
-  error ("Quit (expect signal %d when inferior is resumed)", SIGINT);
-#endif /* TIOCGPGRP */
-#else
-  error ("Quit");
-#endif
+
+  SERIAL_FLUSH_OUTPUT (stdout_serial);
+
+  SERIAL_UN_FDOPEN (stdout_serial);
+
+  /* Don't use *_filtered; we don't want to prompt the user to continue.  */
+  if (error_pre_print)
+    fprintf (stderr, error_pre_print);
+
+  if (job_control
+      /* If there is no terminal switching for this target, then we can't
+        possibly get screwed by the lack of job control.  */
+      || current_target->to_terminal_ours == NULL)
+    fprintf (stderr, "Quit\n");
+  else
+    fprintf (stderr,
+            "Quit (expect signal SIGINT when the program is resumed)\n");
+  return_to_top_level (RETURN_QUIT);

 }
 
 
 }
 
 


@@ -899,17 +917,22 @@ static unsigned int lines_printed, chars_printed;
    spit it out and forget about the wrap_here().  If we see another
    wrap_here(), we spit it out and remember the newer one.  If we see
    the end of the line, we spit out a newline, the indent, and then
    spit it out and forget about the wrap_here().  If we see another
    wrap_here(), we spit it out and remember the newer one.  If we see
    the end of the line, we spit out a newline, the indent, and then

-   the buffered output.
+   the buffered output.  */
+
+/* Malloc'd buffer with chars_per_line+2 bytes.  Contains characters which
+   are waiting to be output (they have already been counted in chars_printed).
+   When wrap_buffer[0] is null, the buffer is empty.  */
+static char *wrap_buffer;
+
+/* Pointer in wrap_buffer to the next character to fill.  */
+static char *wrap_pointer;

 
 

-   wrap_column is the column number on the screen where wrap_buffer begins.
-     When wrap_column is zero, wrapping is not in effect.
-   wrap_buffer is malloc'd with chars_per_line+2 bytes. 
-     When wrap_buffer[0] is null, the buffer is empty.
-   wrap_pointer points into it at the next character to fill.
-   wrap_indent is the string that should be used as indentation if the
-     wrap occurs.  */
+/* String to indent by if the wrap occurs.  Must not be NULL if wrap_column
+   is non-zero.  */
+static char *wrap_indent;

 
 

-static char *wrap_buffer, *wrap_pointer, *wrap_indent;
+/* Column number on the screen where wrap_buffer begins, or 0 if wrapping
+   is not in effect.  */

 static int wrap_column;
 
 /* ARGSUSED */
 static int wrap_column;
 
 /* ARGSUSED */


@@ -943,9 +966,24 @@ prompt_for_continue ()
   reinitialize_more_filter ();
 
   immediate_quit++;
   reinitialize_more_filter ();
 
   immediate_quit++;

-  ignore = gdb_readline ("---Type <return> to continue---");
+  /* On a real operating system, the user can quit with SIGINT.
+     But not on GO32.
+
+     'q' is provided on all systems so users don't have to change habits
+     from system to system, and because telling them what to do in
+     the prompt is more user-friendly than expecting them to think of
+     SIGINT.  */
+  ignore =
+    gdb_readline ("---Type <return> to continue, or q <return> to quit---");

   if (ignore)
   if (ignore)

-    free (ignore);
+    {
+      char *p = ignore;
+      while (*p == ' ' || *p == '\t')
+       ++p;
+      if (p[0] == 'q')
+       request_quit (SIGINT);
+      free (ignore);
+    }

   immediate_quit--;
 
   /* Now we have to do this again, so that GDB will know that it doesn't
   immediate_quit--;
 
   /* Now we have to do this again, so that GDB will know that it doesn't


@@ -966,7 +1004,7 @@ reinitialize_more_filter ()
 
 /* Indicate that if the next sequence of characters overflows the line,
    a newline should be inserted here rather than when it hits the end. 
 
 /* Indicate that if the next sequence of characters overflows the line,
    a newline should be inserted here rather than when it hits the end. 

-   If INDENT is nonzero, it is a string to be printed to indent the
+   If INDENT is non-null, it is a string to be printed to indent the

    wrapped part on the next line.  INDENT must remain accessible until
    the next call to wrap_here() or until a newline is printed through
    fputs_filtered().
    wrapped part on the next line.  INDENT must remain accessible until
    the next call to wrap_here() or until a newline is printed through
    fputs_filtered().


@@ -978,12 +1016,16 @@ reinitialize_more_filter ()
    we must not wrap words, but should still keep track of newlines
    that were explicitly printed.
 
    we must not wrap words, but should still keep track of newlines
    that were explicitly printed.
 

-   INDENT should not contain tabs, as that
-   will mess up the char count on the next line.  FIXME.  */
+   INDENT should not contain tabs, as that will mess up the char count
+   on the next line.  FIXME.
+
+   This routine is guaranteed to force out any output which has been
+   squirreled away in the wrap_buffer, so wrap_here ((char *)0) can be
+   used to force out output from the wrap_buffer.  */

 
 void
 wrap_here(indent)
 
 void
 wrap_here(indent)

-  char *indent;
+     char *indent;

 {
   if (wrap_buffer[0])
     {
 {
   if (wrap_buffer[0])
     {


@@ -999,13 +1041,17 @@ wrap_here(indent)
   else if (chars_printed >= chars_per_line)
     {
       puts_filtered ("\n");
   else if (chars_printed >= chars_per_line)
     {
       puts_filtered ("\n");

-      puts_filtered (indent);
+      if (indent != NULL)
+       puts_filtered (indent);

       wrap_column = 0;
     }
   else
     {
       wrap_column = chars_printed;
       wrap_column = 0;
     }
   else
     {
       wrap_column = chars_printed;

-      wrap_indent = indent;
+      if (indent == NULL)
+       wrap_indent = "";
+      else
+       wrap_indent = indent;

     }
 }
 
     }
 }
 


@@ -1106,8 +1152,7 @@ fputs_filtered (linebuffer, stream)
              /* Now output indentation and wrapped string */
              if (wrap_column)
                {
              /* Now output indentation and wrapped string */
              if (wrap_column)
                {

-                 if (wrap_indent)
-                   fputs (wrap_indent, stream);
+                 fputs (wrap_indent, stream);

                  *wrap_pointer = '\0';         /* Null-terminate saved stuff */
                  fputs (wrap_buffer, stream);  /* and eject it */
                  /* FIXME, this strlen is what prevents wrap_indent from
                  *wrap_pointer = '\0';         /* Null-terminate saved stuff */
                  fputs (wrap_buffer, stream);  /* and eject it */
                  /* FIXME, this strlen is what prevents wrap_indent from