Add GDB pretty-printers

.gdbinit

@@ -0,0 +1,2 @@
+# Register pretty-printers
+source utils/gdb/seer_pretty_printers.py

utils/gdb/seer_pretty_printers.py

@@ -0,0 +1,78 @@
+import gdb.printing
+
+class Square(object):
+    """
+    Wrapper around GDB's representation of a 'seer::board::square::Square' in
+    memory.
+    """
+
+    FILES = list(map(lambda n: chr(ord('A') + n), range(8)))
+    RANKS = list(map(lambda n: str(n + 1), range(8)))
+
+    def __init__(self, val):
+        self._val = val
+
+    def __str__(self):
+        return self.FILES[self.file] + self.RANKS[self.rank]
+
+    @property
+    def rank(self):
+        return int(self._val) % 8
+
+    @property
+    def file(self):
+        return int(self._val) // 8
+
+class Bitboard(object):
+    """
+    Wrapper around GDB's representation of a 'seer::board::bitboard::Bitboard'
+    in memory.
+    """
+
+    def __init__(self, val):
+        self._val = val
+
+    def __str__(self):
+        return "[" + ", ".join(map(str, self.squares)) + "]"
+
+    @property
+    def squares(self):
+        n = int(self._val["__0"])
+        while n:
+            b = n & (~n+1)
+            yield Square(b.bit_length() - 1)
+            n ^= b
+
+class SquarePrinter(object):
+    "Print a seer::board::square::Square"
+
+    def __init__(self, val):
+        self._val = Square(val)
+
+    def to_string(self):
+        return str(self._val)
+
+    def display_hint(self):
+        return 'string'
+
+class BitboardPrinter(object):
+    "Print a seer::board::bitboard::Bitboard"
+
+    def __init__(self, val):
+        self._val = Bitboard(val)
+
+    def to_string(self):
+        return "Bitboard{" + str(self._val)[1:-1] + "}"
+
+    def display_hint(self):
+        return 'string'
+
+def build_pretty_printer():
+    pp = gdb.printing.RegexpCollectionPrettyPrinter('seer')
+
+    pp.add_printer('BigNum', '^seer::board::square::Square$', SquarePrinter)
+    pp.add_printer('BigNum', '^seer::board::bitboard::Bitboard$', BitboardPrinter)
+
+    return pp
+
+gdb.printing.register_pretty_printer(gdb.current_objfile(), build_pretty_printer(), True)