diff --git i/gdb/completer.c w/gdb/completer.c
index c6e1e28..85e6d88 100644
--- i/gdb/completer.c
+++ w/gdb/completer.c
@@ -426,7 +426,6 @@ complete_explicit_location (completion_tracker &tracker,
 			    const char *text, const char *word)
 {
   const char *p;
-  VEC (char_ptr) *matches = NULL;
 
   /* Find the beginning of the word.  This is necessary because
      we need to know if we are completing an option name or value.  We
@@ -1029,6 +1028,8 @@ completion_tracker::completion_tracker ()
 				      NULL, xcalloc, xfree);
 }
 
+/* See completer.h.  */
+
 completion_tracker::~completion_tracker ()
 {
   xfree (m_lowest_common_denominator);
@@ -1062,18 +1063,16 @@ completion_tracker::maybe_add_completion (gdb::unique_xmalloc_ptr<char> name)
   return true;
 }
 
+/* See completer.h.  */
+
 void
 completion_tracker::add_completion (gdb::unique_xmalloc_ptr<char> name)
 {
   if (!maybe_add_completion (std::move (name)))
-    throw_max_completions_reached_error ();
+    throw_error (MAX_COMPLETIONS_REACHED_ERROR, _("Max completions reached."));
 }
 
-void
-throw_max_completions_reached_error (void)
-{
-  throw_error (MAX_COMPLETIONS_REACHED_ERROR, _("Max completions reached."));
-}
+/* See completer.h.  */
 
 void
 completion_tracker::add_completions (completion_list &&list)
@@ -1337,7 +1336,7 @@ completion_tracker::recompute_lowest_common_denominator (const char *new_match)
     }
 }
 
-/* Build a new C string that is a copy or LCD with the whitespace of
+/* Build a new C string that is a copy of LCD with the whitespace of
    ORIG/ORIG_LEN preserved.
 
    Say the user is completing a symbol name, with spaces, like:
@@ -1348,7 +1347,7 @@ completion_tracker::recompute_lowest_common_denominator (const char *new_match)
 
      "foo(int)"
 
-   we want to end up with an inline line like:
+   we want to end up with an input line like:
 
      "foo ( int)"
       ^^^^^^^      => text from LCD [1], whitespace from ORIG preserved.
@@ -1402,6 +1401,8 @@ expand_preserving_ws (const char *orig, size_t orig_len,
   return xstrdup (res.c_str ());
 }
 
+/* See completer.h.  */
+
 completion_result
 completion_tracker::build_completion_result (const char *text,
 					     int start, int end)
@@ -1443,11 +1444,15 @@ completion_tracker::build_completion_result (const char *text,
     }
 }
 
+/* See completer.h  */
+
 completion_result::completion_result ()
   : match_list (NULL), number_matches (0),
     completion_suppress_append (false)
 {}
 
+/* See completer.h  */
+
 completion_result::completion_result (char **match_list_,
 				      size_t number_matches_,
 				      bool completion_suppress_append_)
@@ -1456,11 +1461,15 @@ completion_result::completion_result (char **match_list_,
     completion_suppress_append (completion_suppress_append_)
 {}
 
+/* See completer.h  */
+
 completion_result::~completion_result ()
 {
   reset_match_list ();
 }
 
+/* See completer.h  */
+
 completion_result::completion_result (completion_result &&rhs)
 {
   if (this == &rhs)
@@ -1473,6 +1482,8 @@ completion_result::completion_result (completion_result &&rhs)
   rhs.number_matches = 0;
 }
 
+/* See completer.h  */
+
 char **
 completion_result::release_match_list ()
 {
@@ -1489,6 +1500,8 @@ compare_cstrings (const char *str1, const char *str2)
   return strcmp (str1, str2) < 0;
 }
 
+/* See completer.h  */
+
 void
 completion_result::sort_match_list ()
 {
@@ -1502,6 +1515,8 @@ completion_result::sort_match_list ()
     }
 }
 
+/* See completer.h  */
+
 void
 completion_result::reset_match_list ()
 {
@@ -1515,9 +1530,9 @@ completion_result::reset_match_list ()
 }
 
 /* Helper for gdb_rl_attempted_completion_function, which does most of
-   the work.  This is called by readline to build the match list
-   array, and determining the lowest common denominator.  The real
-   matches list starts at match[1], while match[0] is the slot holding
+   the work.  This is called by readline to build the match list array
+   and to determine the lowest common denominator.  The real matches
+   list starts at match[1], while match[0] is the slot holding
    readline's idea of the lowest common denominator of all matches,
    which is what readline replaces the completion "word" with.
 
diff --git i/gdb/completer.h w/gdb/completer.h
index e554bff..4b3b188 100644
--- i/gdb/completer.h
+++ w/gdb/completer.h
@@ -274,9 +274,4 @@ extern const char *skip_quoted (const char *);
 
 extern int max_completions;
 
-
-/* Wrapper to throw MAX_COMPLETIONS_REACHED_ERROR.  */ 
-
-extern void throw_max_completions_reached_error (void);
-
 #endif /* defined (COMPLETER_H) */
diff --git i/gdb/symtab.c w/gdb/symtab.c
index b70a818..57fb355 100644
--- i/gdb/symtab.c
+++ w/gdb/symtab.c
@@ -5217,9 +5217,8 @@ default_collect_symbol_completion_matches (completion_tracker &tracker,
 							     code);
 }
 
-/* Return a vector of all symbols (regardless of class) which begin by
-   matching TEXT.  If the answer is no symbols, then the return value
-   is NULL.  */
+/* Collect all symbols (regardless of class) which begin by matching
+   TEXT.  */
 
 void
 collect_symbol_completion_matches (completion_tracker &tracker,
@@ -5230,7 +5229,7 @@ collect_symbol_completion_matches (completion_tracker &tracker,
 							  TYPE_CODE_UNDEF);
 }
 
-/* Like collect_symbol_completion_matches, but only return
+/* Like collect_symbol_completion_matches, but only collect
    STRUCT_DOMAIN symbols whose type code is CODE.  */
 
 void
@@ -5406,7 +5405,7 @@ maybe_add_partial_symtab_filename (const char *filename, const char *fullname,
     }
 }
 
-/* Return a vector of all source files whose names begin with matching
+/* Return a list of all source files whose names begin with matching
    TEXT.  The file names are looked up in the symbol tables of this
    program.  */
 
