Re: GDB pretty printers for iterators

[Tom Tromey <tromey at redhat dot com>]

>>>>> "Jonathan" == Jonathan Wakely <jwakely.gcc@gmail.com> writes:

Tom> We could easily add a new gdb parameter to let you choose whether these
Tom> printers are activated. ÂSomething like "set print libstdcxx-iterators off"
Tom> (or whatever name you like).

Jonathan> FWIW I think that's an excellent idea.

I had written the patch, then I forgot about this until last night.

I intend to check this in, barring objections or comments.  It adds a
new option, "set print dereference-iterators", defaulting to enabled.

Tom

2010-03-25  Tom Tromey  <tromey@redhat.com>

	* python/libstdcxx/v6/printers.py (PrintIterators): New class.
	Instantiate it.
	(lookup_function): Check iterator_printers_dict.
	(build_libstdcxx_dictionary): Put iterators into
	iterator_printers_dict.
	(iterator_printers_dict): Initialize.

Index: python/libstdcxx/v6/printers.py
===================================================================
--- python/libstdcxx/v6/printers.py	(revision 157496)
+++ python/libstdcxx/v6/printers.py	(working copy)
@@ -639,6 +639,22 @@
     def display_hint (self):
         return 'map'
 
+# Let the user disable iterator printers.
+class PrintIterators (gdb.Parameter):
+    """When enabled, printing an iterator will automatically dereference it.
+When disabled, an iterator must be explicitly dereferenced using `*'."""
+
+    show_doc = "Show whether libstdc++ iterators are automatically dereferenced when printing."
+
+    set_doc = "Set whether libstdc++ iterators are automatically dereferenced when printing."
+
+    def __init__ (self, name):
+        super (PrintIterators, self).__init__ (name, gdb.COMMAND_DATA,
+                                               gdb.PARAM_BOOLEAN)
+        self.value = True
+
+iterator_param = PrintIterators ("print dereference-iterators")
+
 def register_libstdcxx_printers (obj):
     "Register libstdc++ pretty-printers with objfile Obj."
 
@@ -672,6 +688,11 @@
         if function.search (typename):
             return pretty_printers_dict[function] (val)
         
+    if iterator_param.value:
+        for function in iterator_printers_dict:
+            if function.search (typename):
+                return iterator_printers_dict[function] (val)
+
     # Cannot find a pretty printer.  Return None.
     return None
 
@@ -740,24 +761,25 @@
     if True:
         # These shouldn't be necessary, if GDB "print *i" worked.
         # But it often doesn't, so here they are.
-        pretty_printers_dict[re.compile('^std::_List_iterator<.*>$')] = lambda val: StdListIteratorPrinter("std::_List_iterator",val)
-        pretty_printers_dict[re.compile('^std::_List_const_iterator<.*>$')] = lambda val: StdListIteratorPrinter("std::_List_const_iterator",val)
-        pretty_printers_dict[re.compile('^std::_Rb_tree_iterator<.*>$')] = lambda val: StdRbtreeIteratorPrinter(val)
-        pretty_printers_dict[re.compile('^std::_Rb_tree_const_iterator<.*>$')] = lambda val: StdRbtreeIteratorPrinter(val)
-        pretty_printers_dict[re.compile('^std::_Deque_iterator<.*>$')] = lambda val: StdDequeIteratorPrinter(val)
-        pretty_printers_dict[re.compile('^std::_Deque_const_iterator<.*>$')] = lambda val: StdDequeIteratorPrinter(val)
-        pretty_printers_dict[re.compile('^__gnu_cxx::__normal_iterator<.*>$')] = lambda val: StdVectorIteratorPrinter(val)
-        pretty_printers_dict[re.compile('^__gnu_cxx::_Slist_iterator<.*>$')] = lambda val: StdSlistIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^std::_List_iterator<.*>$')] = lambda val: StdListIteratorPrinter("std::_List_iterator",val)
+        iterator_printers_dict[re.compile('^std::_List_const_iterator<.*>$')] = lambda val: StdListIteratorPrinter("std::_List_const_iterator",val)
+        iterator_printers_dict[re.compile('^std::_Rb_tree_iterator<.*>$')] = lambda val: StdRbtreeIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^std::_Rb_tree_const_iterator<.*>$')] = lambda val: StdRbtreeIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^std::_Deque_iterator<.*>$')] = lambda val: StdDequeIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^std::_Deque_const_iterator<.*>$')] = lambda val: StdDequeIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^__gnu_cxx::__normal_iterator<.*>$')] = lambda val: StdVectorIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^__gnu_cxx::_Slist_iterator<.*>$')] = lambda val: StdSlistIteratorPrinter(val)
 
         # Debug (compiled with -D_GLIBCXX_DEBUG) printer registrations.
         # The Rb_tree debug iterator when unwrapped from the encapsulating __gnu_debug::_Safe_iterator
         # does not have the __norm namespace. Just use the existing printer registration for that.
-        pretty_printers_dict[re.compile('^__gnu_debug::_Safe_iterator<.*>$')] = lambda val: StdDebugIteratorPrinter(val)
-        pretty_printers_dict[re.compile('^std::__norm::_List_iterator<.*>$')] = lambda val: StdListIteratorPrinter ("std::__norm::_List_iterator",val)
-        pretty_printers_dict[re.compile('^std::__norm::_List_const_iterator<.*>$')] = lambda val: StdListIteratorPrinter ("std::__norm::_List_const_iterator",val)
-        pretty_printers_dict[re.compile('^std::__norm::_Deque_const_iterator<.*>$')] = lambda val: StdDequeIteratorPrinter(val)
-        pretty_printers_dict[re.compile('^std::__norm::_Deque_iterator<.*>$')] = lambda val: StdDequeIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^__gnu_debug::_Safe_iterator<.*>$')] = lambda val: StdDebugIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^std::__norm::_List_iterator<.*>$')] = lambda val: StdListIteratorPrinter ("std::__norm::_List_iterator",val)
+        iterator_printers_dict[re.compile('^std::__norm::_List_const_iterator<.*>$')] = lambda val: StdListIteratorPrinter ("std::__norm::_List_const_iterator",val)
+        iterator_printers_dict[re.compile('^std::__norm::_Deque_const_iterator<.*>$')] = lambda val: StdDequeIteratorPrinter(val)
+        iterator_printers_dict[re.compile('^std::__norm::_Deque_iterator<.*>$')] = lambda val: StdDequeIteratorPrinter(val)
 
 pretty_printers_dict = {}
+iterator_printers_dict = {}
 
 build_libstdcxx_dictionary ()