[PATCH 09/18] Implement completion limiting for interpreter_completer.

[Keith Seitz <keiths at redhat dot com>]

This is another simple patch which converts interpreter_completer
to use maybe_add_completion and adds some tests to make sure
that everything is working properly.

gdb/ChangeLog

	* interps.c (interpreter_completer): Use maybe_add_completion.

gdb/testsuite/ChangeLog

	* gdb.base/completion.exp: Test completion limiting on
	interpreter name with "interpreter-exec".
---
 gdb/interps.c                         |   19 ++++++++++++++++++-
 gdb/testsuite/gdb.base/completion.exp |   16 ++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/gdb/interps.c b/gdb/interps.c
index ac1b512..085cac5 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -451,6 +451,7 @@ interpreter_completer (struct completer_data *cdata,
       if (strncmp (interp->name, text, textlen) == 0)
 	{
 	  char *match;
+	  enum maybe_add_completion_enum add_status;
 
 	  match = (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 	  if (word == text)
@@ -467,7 +468,23 @@ interpreter_completer (struct completer_data *cdata,
 	      match[text - word] = '\0';
 	      strcat (match, interp->name);
 	    }
-	  VEC_safe_push (char_ptr, matches, match);
+
+	  add_status = maybe_add_completion (cdata, match);
+	  switch (add_status)
+	    {
+	    case MAYBE_ADD_COMPLETION_OK:
+	      VEC_safe_push (char_ptr, matches, match);
+	      break;
+	    case MAYBE_ADD_COMPLETION_OK_MAX_REACHED:
+	      VEC_safe_push (char_ptr, matches, match);
+	      return matches;
+	    case MAYBE_ADD_COMPLETION_MAX_REACHED:
+	      xfree (match);
+	      return matches;
+	    case MAYBE_ADD_COMPLETION_DUPLICATE:
+	      xfree (match);
+	      break;
+	    }
 	}
     }
 
diff --git a/gdb/testsuite/gdb.base/completion.exp b/gdb/testsuite/gdb.base/completion.exp
index 90cdb36..d07ca86 100644
--- a/gdb/testsuite/gdb.base/completion.exp
+++ b/gdb/testsuite/gdb.base/completion.exp
@@ -1021,3 +1021,19 @@ if {$num_signals > $max_completions} {
     append msg "limiting in signal_handler ($num_signals)"
     untested $msg
 }
+
+# Test interpreter_completer.  There are only four completions
+# available for this, so temporarily set max-completions to 3.
+with_test_prefix "interpreter_completer" {
+    set old_max $max_completions
+    set max_completions 3
+    gdb_test_no_output "set max-completions $max_completions"
+}
+
+test_completion_limit "interpreter-exec m" \
+    "interpreter-exec mi\[1-3\]?" $max_completions
+
+with_test_prefix "interpreter_completer reset" {
+    set max_completions $old_max
+    gdb_test_no_output "set max-completions $max_completions"
+}