Add 'Move' GDB pretty-printing

utils/gdb/seer_pretty_printers.py

@@ -114,6 +114,89 @@ class Piece(enum.IntEnum):
         return self.name.title()
 
 
+class Move(object):
+    """
+    Wrapper around GDB's representation of a 'seer::board::move::Move'
+    in memory.
+    """
+
+    # Should be kept in sync with the values in `move.rs`
+    PIECE_SHIFT = 0
+    PIECE_MASK = 0b111
+    START_SHIFT = 3
+    START_MASK = 0b11_1111
+    DESTINATION_SHIFT = 9
+    DESTINATION_MASK = 0b11_1111
+    CAPTURE_SHIFT = 15
+    CAPTURE_MASK = 0b111
+    PROMOTION_SHIFT = 18
+    PROMOTION_MASK = 0b111
+    EN_PASSANT_SHIFT = 21
+    EN_PASSANT_MASK = 0b1
+    DOUBLE_STEP_SHIFT = 22
+    DOUBLE_STEP_MASK = 0b1
+    CASTLING_SHIFT = 23
+    CASTLING_MASK = 0b1
+
+    def __init__(self, val):
+        self._val = val
+
+    @property
+    def piece(self):
+        return Piece(self._val >> self.PIECE_SHIFT & self.PIECE_MASK)
+
+    @property
+    def start(self):
+        return Square(self._val >> self.START_SHIFT & self.START_MASK)
+
+    @property
+    def destination(self):
+        return Square(self._val >> self.DESTINATION_SHIFT & self.DESTINATION_MASK)
+
+    @property
+    def capture(self):
+        index = self._val >> self.CAPTURE_SHIFT & self.CAPTURE_MASK
+        if index == 7:
+            return None
+        return Piece(index)
+
+    @property
+    def promotion(self):
+        index = self._val >> self.PROMOTION_SHIFT & self.PROMOTION_MASK
+        if index == 7:
+            return None
+        return Piece(index)
+
+    @property
+    def en_passant(self):
+        return bool(self._val >> self.EN_PASSANT_SHIFT & self.EN_PASSANT_MASK)
+
+    @property
+    def double_step(self):
+        return bool(self._val >> self.DOUBLE_STEP_SHIFT & self.DOUBLE_STEP_MASK)
+
+    @property
+    def castling(self):
+        return bool(self._val >> self.CASTLING_SHIFT & self.CASTLING_MASK)
+
+    def __str__(self):
+        KEYS = [
+            "piece",
+            "start",
+            "destination",
+            "capture",
+            "promotion",
+            "en_passant",
+            "double_step",
+            "castling",
+        ]
+        print_opt = lambda val: "(None)" if val is None else str(val)
+        indent = lambda s: "    " + s
+
+        values = [key + ": " + print_opt(getattr(self, key)) + ",\n" for key in KEYS]
+        return "Move{\n" + "".join(map(indent, values)) + "}"
+
+
 class SquarePrinter(object):
     "Print a seer::board::square::Square"
 
@@ -174,6 +257,16 @@ class PiecePrinter(object):
         return str(self._val)
 
 
+class MovePrinter(object):
+    "Print a seer::board::move::Move"
+
+    def __init__(self, val):
+        self._val = Move(int(val["__0"]))
+
+    def to_string(self):
+        return str(self._val)
+
+
 def build_pretty_printer():
     pp = gdb.printing.RegexpCollectionPrettyPrinter('seer')
 
@@ -183,6 +276,7 @@ def build_pretty_printer():
     pp.add_printer('File', '^seer::board::file::File$', FilePrinter)
     pp.add_printer('Rank', '^seer::board::rank::Rank$', RankPrinter)
     pp.add_printer('Piece', '^seer::board::piece::Piece$', ColorPrinter)
+    pp.add_printer('Move', '^seer::board::move::Move$', MovePrinter)
 
     return pp