gcc编译gtk程序时的一个warning

程序：
callback_sendKeyword (GtkWidget *widget, GtkWidget *entry)
{
  gchar *entry_text;

  printf ("Confirm button pressed\n");

  entry_text = gtk_entry_get_text(GTK_ENTRY(entry));
  printf ("Entry contents: %s\n", entry_text);

}
编译时提示:
entry_text = gtk_entry_get_text(GTK_ENTRY(entry));此行
warning: fix for: assignment discards qualifiers from pointer target type
百思不得其解，查了查gtk_entry_get_text()接口定义如下：
gtk_entry_get_text ()

const gchar* gtk_entry_get_text (GtkEntry *entry);

Retrieves the contents of the entry widget. See also gtk_editable_get_chars().

entry : a GtkEntry
Returns : a pointer to the contents of the widget as a string. This string points to internally allocated storage in the widget and must not be freed, modified or stored.

将程序中
gchar *entry_text;
改为
const char *entry_text;
无此警告。