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1# Copyright 2017 Google Inc.
2#
3# Use of this source code is governed by a BSD-style license that can be
4# found in the LICENSE file.
5
6"""
7Visualize bitmaps in gdb.
8
9(gdb) source <path to this file>
10(gdb) sk_bitmap <symbol>
11
12This should pop up a window with the bitmap displayed.
13Right clicking should bring up a menu, allowing the
14bitmap to be saved to a file.
15"""
16
17import gdb
18from enum import Enum
19try:
20  from PIL import Image
21except ImportError:
22  import Image
23
24class ColorType(Enum):
25    unknown = 0
26    alpha_8 = 1
27    rgb_565 = 2
28    argb_4444 = 3
29    rgba_8888 = 4
30    rgbx_8888 = 5
31    bgra_8888 = 6
32    rgba_1010102 = 7
33    rgb_101010x = 8
34    gray_8 = 9
35    rgba_F16 = 10
36
37class AlphaType(Enum):
38    unknown = 0
39    opaque = 1
40    premul = 2
41    unpremul = 3
42
43class sk_bitmap(gdb.Command):
44  """Displays the content of an SkBitmap image."""
45
46  def __init__(self):
47      super(sk_bitmap, self).__init__('sk_bitmap',
48                                      gdb.COMMAND_SUPPORT,
49                                      gdb.COMPLETE_FILENAME)
50
51  def invoke(self, arg, from_tty):
52    frame = gdb.selected_frame()
53    val = frame.read_var(arg)
54    if str(val.type.strip_typedefs()) == 'SkBitmap':
55      pixmap = val['fPixmap']
56      pixels = pixmap['fPixels']
57      row_bytes = pixmap['fRowBytes']
58      info = pixmap['fInfo']
59      dimensions = info['fDimensions']
60      width = dimensions['fWidth']
61      height = dimensions['fHeight']
62      color_type = info['fColorType']
63      alpha_type = info['fAlphaType']
64
65      process = gdb.selected_inferior()
66      memory_data = process.read_memory(pixels, row_bytes * height)
67      size = (width, height)
68      image = None
69      # See Unpack.c for the values understood after the "raw" parameter.
70      if color_type == ColorType.bgra_8888.value:
71        if alpha_type == AlphaType.unpremul.value:
72          image = Image.frombytes("RGBA", size, memory_data,
73                                  "raw", "BGRA", row_bytes, 1)
74        elif alpha_type == AlphaType.premul.value:
75          # RGBA instead of RGBa, because Image.show() doesn't work with RGBa.
76          image = Image.frombytes("RGBA", size, memory_data,
77                                  "raw", "BGRa", row_bytes, 1)
78
79      if image:
80        # Fails on premultiplied alpha, it cannot convert to RGB.
81        image.show()
82      else:
83        print ("Need to add support for %s %s." % (
84               str(ColorType(int(color_type))),
85               str(AlphaType(int(alpha_type)))
86        ))
87
88sk_bitmap()
89