Change input_handler to take a unique_xmalloc_ptr

This changes ui::input_handler to take a unique_xmalloc_ptr.  This
clarifies the ownership transfer of input_handler's argument.

gdb/ChangeLog
2018-12-30  Tom Tromey  <tom@tromey.com>

	* event-top.h (command_line_handler): Update.
	* top.c (class gdb_readline_wrapper_cleanup) <m_handler_orig>:
	Update.
	(gdb_readline_wrapper_line): Update.
	* top.h (struct ui) <input_handler>: Take a unique_xmalloc_ptr.
	(handle_line_of_input): Update.
	* event-top.c: Update.
	(gdb_readline_no_editing_callback): Update.
	(command_line_handler): Take a unique_xmalloc_ptr.
	(handle_line_of_input): Take a const char *.
	(command_line_append_input_line): Take a const char *.

6 files changed, 32 insertions, 19 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 5ed91a84fc3..7be4360e623 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,17 @@
+2018-12-30  Tom Tromey  <tom@tromey.com>
+
+	* event-top.h (command_line_handler): Update.
+	* top.c (class gdb_readline_wrapper_cleanup) <m_handler_orig>:
+	Update.
+	(gdb_readline_wrapper_line): Update.
+	* top.h (struct ui) <input_handler>: Take a unique_xmalloc_ptr.
+	(handle_line_of_input): Update.
+	* event-top.c: Update.
+	(gdb_readline_no_editing_callback): Update.
+	(command_line_handler): Take a unique_xmalloc_ptr.
+	(handle_line_of_input): Take a const char *.
+	(command_line_append_input_line): Take a const char *.
+
 2018-12-28  Tom Tromey  <tom@tromey.com>
 
 	* source-cache.c (get_language_name): Conditionally compile.
diff --git a/gdb/event-top.c b/gdb/event-top.c
index 5852089f09c..7eef55bb8d9 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -210,7 +210,7 @@ gdb_rl_callback_handler (char *rl) noexcept
 
   TRY
     {
-      ui->input_handler (rl);
+      ui->input_handler (gdb::unique_xmalloc_ptr<char> (rl));
     }
   CATCH (ex, RETURN_MASK_ALL)
     {
@@ -591,10 +591,10 @@ command_handler (const char *command)
    emulations, to CMD_LINE_BUFFER.  Returns the command line if we
    have a whole command line ready to be processed by the command
    interpreter or NULL if the command line isn't complete yet (input
-   line ends in a backslash).  Takes ownership of RL.  */
+   line ends in a backslash).  */
 
 static char *
-command_line_append_input_line (struct buffer *cmd_line_buffer, char *rl)
+command_line_append_input_line (struct buffer *cmd_line_buffer, const char *rl)
 {
   char *cmd;
   size_t len;
@@ -615,9 +615,6 @@ command_line_append_input_line (struct buffer *cmd_line_buffer, char *rl)
       cmd = cmd_line_buffer->buffer;
     }
 
-  /* Allocated in readline.  */
-  xfree (rl);
-
   return cmd;
 }
 
@@ -643,7 +640,8 @@ command_line_append_input_line (struct buffer *cmd_line_buffer, char *rl)
 
 char *
 handle_line_of_input (struct buffer *cmd_line_buffer,
-		      char *rl, int repeat, const char *annotation_suffix)
+		      const char *rl, int repeat,
+		      const char *annotation_suffix)
 {
   struct ui *ui = current_ui;
   int from_tty = ui->instream == ui->stdin_stream;
@@ -746,13 +744,13 @@ handle_line_of_input (struct buffer *cmd_line_buffer,
    function.  */
 
 void
-command_line_handler (char *rl)
+command_line_handler (gdb::unique_xmalloc_ptr<char> &&rl)
 {
   struct buffer *line_buffer = get_command_line_buffer ();
   struct ui *ui = current_ui;
   char *cmd;
 
-  cmd = handle_line_of_input (line_buffer, rl, 1, "prompt");
+  cmd = handle_line_of_input (line_buffer, rl.get (), 1, "prompt");
   if (cmd == (char *) EOF)
     {
       /* stdin closed.  The connection with the terminal is gone.
@@ -846,7 +844,7 @@ gdb_readline_no_editing_callback (gdb_client_data client_data)
 
   buffer_grow_char (&line_buffer, '\0');
   result = buffer_finish (&line_buffer);
-  ui->input_handler (result);
+  ui->input_handler (gdb::unique_xmalloc_ptr<char> (result));
 }
 
 
diff --git a/gdb/event-top.h b/gdb/event-top.h
index a77303e5c34..1164f690719 100644
--- a/gdb/event-top.h
+++ b/gdb/event-top.h
@@ -35,7 +35,7 @@ extern void gdb_disable_readline (void);
 extern void async_init_signals (void);
 extern void change_line_handler (int);
 
-extern void command_line_handler (char *rl);
+extern void command_line_handler (gdb::unique_xmalloc_ptr<char> &&rl);
 extern void command_handler (const char *command);
 
 #ifdef SIGTSTP
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index 9a317bc0ecd..fd446c20e69 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -43,7 +43,8 @@
    interpreter.  */
 
 static void mi_execute_command_wrapper (const char *cmd);
-static void mi_execute_command_input_handler (char *cmd);
+static void mi_execute_command_input_handler
+  (gdb::unique_xmalloc_ptr<char> &&cmd);
 
 /* These are hooks that we put in place while doing interpreter_exec
    so we can report interesting things that happened "behind the MI's
@@ -294,14 +295,14 @@ mi_on_sync_execution_done (void)
 /* mi_execute_command_wrapper wrapper suitable for INPUT_HANDLER.  */
 
 static void
-mi_execute_command_input_handler (char *cmd)
+mi_execute_command_input_handler (gdb::unique_xmalloc_ptr<char> &&cmd)
 {
   struct mi_interp *mi = as_mi_interp (top_level_interpreter ());
   struct ui *ui = current_ui;
 
   ui->prompt_state = PROMPT_NEEDED;
 
-  mi_execute_command_wrapper (cmd);
+  mi_execute_command_wrapper (cmd.get ());
 
   /* Print a prompt, indicating we're ready for further input, unless
      we just started a synchronous command.  In that case, we're about
diff --git a/gdb/top.c b/gdb/top.c
index 4bcb4e28fbc..8b3fc5ee9a0 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -900,10 +900,10 @@ gdb_in_secondary_prompt_p (struct ui *ui)
    text.  */
 
 static void
-gdb_readline_wrapper_line (char *line)
+gdb_readline_wrapper_line (gdb::unique_xmalloc_ptr<char> &&line)
 {
   gdb_assert (!gdb_readline_wrapper_done);
-  gdb_readline_wrapper_result = line;
+  gdb_readline_wrapper_result = line.release ();
   gdb_readline_wrapper_done = 1;
 
   /* Prevent operate-and-get-next from acting too early.  */
@@ -972,7 +972,7 @@ public:
 
 private:
 
-  void (*m_handler_orig) (char *);
+  void (*m_handler_orig) (gdb::unique_xmalloc_ptr<char> &&);
   int m_already_prompted_orig;
 
   /* Whether the target was async.  */
diff --git a/gdb/top.h b/gdb/top.h
index b34defa1f29..4d11f3443b0 100644
--- a/gdb/top.h
+++ b/gdb/top.h
@@ -81,7 +81,7 @@ struct ui
 
   /* The function to invoke when a complete line of input is ready for
      processing.  */
-  void (*input_handler) (char *);
+  void (*input_handler) (gdb::unique_xmalloc_ptr<char> &&);
 
   /* True if this UI is using the readline library for command
      editing; false if using GDB's own simple readline emulation, with
@@ -297,7 +297,7 @@ extern void show_history (const char *, int);
 extern void set_verbose (const char *, int, struct cmd_list_element *);
 
 extern char *handle_line_of_input (struct buffer *cmd_line_buffer,
-				   char *rl, int repeat,
+				   const char *rl, int repeat,
 				   const char *annotation_suffix);
 
 #endif