[PATCH 08/10] Use struct buffer in gdb_readline_callback_no_editing

[Pedro Alves <palves at redhat dot com>]

gdb/ChangeLog:
2016-02-18  Pedro Alves  <palves@redhat.com>

	* event-top.c: Include buffer.h.
	(gdb_readline_callback_no_editing): Use struct buffer instead of
	xrealloc.
---
 gdb/event-top.c | 39 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/gdb/event-top.c b/gdb/event-top.c
index ee44197..3447fc8 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -37,6 +37,7 @@
 #include "gdbcmd.h"		/* for dont_repeat() */
 #include "annotate.h"
 #include "maint.h"
+#include "buffer.h"
 
 /* readline include files.  */
 #include "readline/readline.h"
@@ -382,7 +383,7 @@ top_level_prompt (void)
   return xstrdup (prompt);
 }
 
-/* When there is an event ready on the stdin file desriptor, instead
+/* When there is an event ready on the stdin file descriptor, instead
    of calling readline directly throught the callback function, or
    instead of calling gdb_readline_callback_no_editing, give gdb a
    chance to detect errors and do something.  */
@@ -678,10 +679,11 @@ gdb_readline_callback_no_editing (gdb_client_data client_data)
 {
   int c;
   char *result;
-  int input_index = 0;
-  int result_size = 80;
+  struct buffer line_buffer;
   static int done_once = 0;
 
+  buffer_init (&line_buffer);
+
   /* Unbuffer the input stream, so that, later on, the calls to fgetc
      fetch only one char at the time from the stream.  The fgetc's will
      get up to the first newline, but there may be more chars in the
@@ -694,8 +696,6 @@ gdb_readline_callback_no_editing (gdb_client_data client_data)
       done_once = 1;
     }
 
-  result = (char *) xmalloc (result_size);
-
   /* We still need the while loop here, even though it would seem
      obvious to invoke gdb_readline_callback_no_editing at every
      character entered.  If not using the readline library, the
@@ -712,32 +712,31 @@ gdb_readline_callback_no_editing (gdb_client_data client_data)
 
       if (c == EOF)
 	{
-	  if (input_index > 0)
-	    /* The last line does not end with a newline.  Return it,
-	       and if we are called again fgetc will still return EOF
-	       and we'll return NULL then.  */
-	    break;
-	  xfree (result);
+	  if (line_buffer.used_size > 0)
+	    {
+	      /* The last line does not end with a newline.  Return it, and
+		 if we are called again fgetc will still return EOF and
+		 we'll return NULL then.  */
+	      break;
+	    }
+	  xfree (buffer_finish (&line_buffer));
 	  (*input_handler) (0);
 	  return;
 	}
 
       if (c == '\n')
 	{
-	  if (input_index > 0 && result[input_index - 1] == '\r')
-	    input_index--;
+	  if (line_buffer.used_size > 0
+	      && line_buffer.buffer[line_buffer.used_size - 1] == '\r')
+	    line_buffer.used_size--;
 	  break;
 	}
 
-      result[input_index++] = c;
-      while (input_index >= result_size)
-	{
-	  result_size *= 2;
-	  result = (char *) xrealloc (result, result_size);
-	}
+      buffer_grow_char (&line_buffer, c);
     }
 
-  result[input_index++] = '\0';
+  buffer_grow_char (&line_buffer, '\0');
+  result = buffer_finish (&line_buffer);
   (*input_handler) (result);
 }
 
-- 
1.9.3