Write GDB pretty-printers for FCA containers, without fancy pointers

extra/boost_unordered_printers.py

@@ -0,0 +1,88 @@
+# Copyright 2024 Braden Ganetsky
+# Distributed under the Boost Software License, Version 1.0.
+# https://www.boost.org/LICENSE_1_0.txt
+
+import gdb.printing
+
+class BoostUnorderedFcaPrinter:
+    def __init__(self, val):
+        self.val = val
+        self.name = f"{self.val.type.strip_typedefs()}".split("<")[0]
+        self.name = self.name.replace("boost::unordered::", "boost::")
+        self.is_map = self.name.endswith("map")
+
+    def to_string(self):
+        size = self.val["table_"]["size_"]
+        return f"{self.name} with {size} elements"
+
+    def display_hint(self):
+        return "map"
+
+    def to_address(self, arg):
+        return arg # TODO: Add fancy pointer support
+
+    def next(self, arg, n):
+        return arg + n # TODO: Add fancy pointer support
+
+    def children(self):
+        def generator():
+            grouped_buckets = self.val["table_"]["buckets_"]
+
+            size = grouped_buckets["size_"]
+            buckets = grouped_buckets["buckets"]
+            bucket_index = 0
+            current_bucket = self.to_address(buckets)
+            node = self.to_address(current_bucket.dereference()["next"])
+
+            count = 0
+            while bucket_index != size:
+                current_bucket = self.next(self.to_address(buckets), bucket_index)
+                node = self.to_address(current_bucket.dereference()["next"])
+                while node != 0:
+                    value = node.dereference()["buf"]["t_"]
+                    if self.is_map:
+                        first = value["first"]
+                        second = value["second"]
+                        yield "", first
+                        yield "", second
+                    else:
+                        yield "", count
+                        yield "", value
+                    count += 1
+                    node = self.to_address(node.dereference()["next"])
+                bucket_index += 1
+        
+        return generator()
+
+class BoostUnorderedFcaIteratorPrinter:
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        if self.valid():
+            value = self.to_address(self.val["p"]).dereference()["buf"]["t_"]
+            return f"iterator = {{ {value} }}"
+        else:
+            return "iterator = { end iterator }"
+
+    def to_address(self, arg):
+        return arg # TODO: Add fancy pointer support
+
+    def valid(self):
+        return (self.to_address(self.val["p"]) != 0) and (self.to_address(self.val["itb"]["p"]) != 0)
+
+def boost_unordered_build_pretty_printer():
+    pp = gdb.printing.RegexpCollectionPrettyPrinter("boost_unordered")
+    add_template_printer = lambda name, printer: pp.add_printer(name, f"^{name}<.*>$", printer)
+
+    add_template_printer("boost::unordered::unordered_map", BoostUnorderedFcaPrinter)
+    add_template_printer("boost::unordered::unordered_multimap", BoostUnorderedFcaPrinter)
+    add_template_printer("boost::unordered::unordered_set", BoostUnorderedFcaPrinter)
+    add_template_printer("boost::unordered::unordered_multiset", BoostUnorderedFcaPrinter)
+
+    add_template_printer("boost::unordered::detail::iterator_detail::iterator", BoostUnorderedFcaIteratorPrinter)
+    add_template_printer("boost::unordered::detail::iterator_detail::c_iterator", BoostUnorderedFcaIteratorPrinter)
+
+    return pp
+
+gdb.printing.register_pretty_printer(gdb.current_objfile(), boost_unordered_build_pretty_printer())