Initial commit

devtools/gdb_pretty_printers.py

@@ -0,0 +1,192 @@
+"""
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+"""
+
+"""
+USAGE:
+inside gdb, use:
+> source devtools/gdb_pretty_printers.py
+"""
+
+class StringPrinter:
+    "Prints Common::String and Common::U32String"
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        return self.val["_str"].string()
+
+    def display_hint(self):
+        return "string"
+
+
+class ArrayPrinter:
+    "Prints Common::Array"
+
+    class _iterator:
+        def __init__(self, start, item_count):
+            self.current_item = start
+            self.item_count = item_count
+            self.current_item_count = 0
+            self.item_size = 8 * start.dereference().type.sizeof
+
+        def __iter__(self):
+            return self
+
+        def __next__(self):
+            if self.current_item_count == self.item_count:
+                raise StopIteration
+            value = self.current_item.dereference()
+            index = self.current_item_count
+            self.current_item_count += 1
+            self.current_item += 1
+            return f"[{index}]", value
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        size = self.val["_size"]
+        capacity = self.val["_capacity"]
+        return f"{self.val.type.name} of length {size}, capacity {capacity}"
+
+    def children(self):
+        return self._iterator(self.val["_storage"], self.val["_size"])
+
+    def display_hint(self):
+        return "array"
+
+class RBTreeIterator:
+    "Utility iterator for Common::RBTree"
+
+    def __init__(self, leftmost, item_count):
+        self.current_node = leftmost
+        self.item_count = item_count
+        self.current_item_count = 0
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.current_item_count == self.item_count:
+            raise StopIteration
+        value = self.current_node.dereference()["value"]
+        self.current_item_count += 1
+        if self.current_node.dereference()["right"]:
+            while self.current_node.dereference()["left"]:
+                self.current_node = self.current_node.dereference()["left"]
+        else:
+            parent = self.current_node.dereference()["parent"]
+            while parent and parent.dereference()["right"] == self.current_node.dereference()["right"]:
+                self.current_node = parent
+                parent = self.current_node.dereference()["parent"]
+        return value
+
+class RBTreeMapPrinter:
+    "Prints Common::StableMap and Common::MultiMap"
+
+    class _iterator:
+        def __init__(self, rb_tree):
+            self.iter = RBTreeIterator(rb_tree["_leftmost"], rb_tree["_size"])
+            self.count = 0
+
+        def __iter__(self):
+            return self
+
+        def __next__(self):
+            if self.count % 2 == 0:
+                value = next(self.iter)
+                self.current_pair = value
+                item = value["first"]
+            else:
+                item = self.current_pair["second"]
+            self.count += 1
+            return f"{self.count}", item
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        size = self.val["_items"]["_size"]
+        return f"{self.val.type.name} of length {size}"
+
+    def children(self):
+        return self._iterator(self.val["_items"])
+
+    def display_hint(self):
+        return "map"
+
+
+class ListPrinter:
+    "Prints Common::List"
+
+    class _iterator:
+        def __init__(self, anchor, typename):
+            self.anchor = anchor
+            self.current_node = anchor["_next"].dereference()
+            self.current_item_count = 0
+            self.node_type = gdb.lookup_type(f"{typename}::Node")
+
+        def __iter__(self):
+            return self
+
+        def __next__(self):
+            if self.current_node.address == self.anchor.address:
+                raise StopIteration
+            value = self.current_node.cast(self.node_type)["_data"]
+            index = self.current_item_count
+            self.current_item_count += 1
+            self.current_node = self.current_node["_next"].dereference()
+            return f"[{index}]", value
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        if self.val["_anchor"]["_next"] == self.val["_anchor"].address:
+            return f"empty {self.val.type.name}"
+        return self.val.type.name
+
+    def children(self):
+        return self._iterator(self.val["_anchor"], self.val.type.name)
+
+    def display_hint(self):
+        return "array"
+
+import gdb.printing
+
+def build_pretty_printer():
+    pp = gdb.printing.RegexpCollectionPrettyPrinter(
+        "Common")
+    pp.add_printer('String', '^Common::String$', StringPrinter)
+    pp.add_printer('U32String', '^Common::U32String$', StringPrinter)
+    pp.add_printer('Array', '^Common::Array<.*>$', ArrayPrinter)
+    pp.add_printer('StableMap', '^Common::StableMap<.*>$', RBTreeMapPrinter)
+    pp.add_printer('MultiMap', '^Common::MultiMap<.*>$', RBTreeMapPrinter)
+    pp.add_printer('List', '^Common::List<.*>$',  ListPrinter)
+    return pp
+
+gdb.printing.register_pretty_printer(
+    gdb.current_objfile(),
+    build_pretty_printer()
+)