зеркало из https://github.com/mozilla/gecko-dev.git
153 строки
4.2 KiB
Python
153 строки
4.2 KiB
Python
# Copyright 2013 The Servo Project Developers. See the COPYRIGHT
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# file at the top-level directory of this distribution.
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#
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# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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# option. This file may not be copied, modified, or distributed
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# except according to those terms.
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"""
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A set of simple pretty printers for gdb to make debugging Servo a bit easier.
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To load these, you need to add something like the following to your .gdbinit file:
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python
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import sys
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sys.path.insert(0, '/home/<path to git checkout>/servo/src/etc')
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import servo_gdb
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servo_gdb.register_printers(None)
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end
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"""
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import gdb
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# Print Au in both raw value and CSS pixels
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class AuPrinter:
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def __init__(self, val):
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self.val = val
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def to_string(self):
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i32_type = gdb.lookup_type("i32")
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au = self.val.cast(i32_type)
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return "{0}px".format(au / 60.0)
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# Print a U8 bitfield as binary
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class BitFieldU8Printer:
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def __init__(self, val):
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self.val = val
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def to_string(self):
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u8_type = gdb.lookup_type("u8")
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value = self.val.cast(u8_type)
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return "[{0:#010b}]".format(int(value))
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# Print a struct with fields as children
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class ChildPrinter:
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def __init__(self, val):
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self.val = val
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def children(self):
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children = []
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for f in self.val.type.fields():
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children.append((f.name, self.val[f.name]))
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return children
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def to_string(self):
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return None
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# Allow a trusted node to be dereferenced in the debugger
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class TrustedNodeAddressPrinter:
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def __init__(self, val):
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self.val = val
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def children(self):
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node_type = gdb.lookup_type("struct script::dom::node::Node").pointer()
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value = self.val.cast(node_type)
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return [('Node', value)]
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def to_string(self):
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return self.val.address
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# Extract a node type ID from enum
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class NodeTypeIdPrinter:
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def __init__(self, val):
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self.val = val
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def to_string(self):
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u8_ptr_type = gdb.lookup_type("u8").pointer()
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enum_0 = self.val.address.cast(u8_ptr_type).dereference()
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enum_type = self.val.type.fields()[int(enum_0)].type
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return str(enum_type).lstrip('struct ')
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# Printer for std::Option<>
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class OptionPrinter:
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def __init__(self, val):
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self.val = val
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def is_some(self):
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# Get size of discriminator
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d_size = self.val.type.fields()[0].type.sizeof
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if d_size > 0 and d_size <= 8:
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# Read first byte to check if None or Some
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ptr = self.val.address.cast(gdb.lookup_type("unsigned char").pointer())
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discriminator = int(ptr.dereference())
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return discriminator != 0
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raise "unhandled discriminator size"
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def children(self):
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if self.is_some():
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option_type = self.val.type
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# Get total size and size of value
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ptr = self.val.address.cast(gdb.lookup_type("unsigned char").pointer())
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t_size = option_type.sizeof
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value_type = option_type.fields()[1].type.fields()[1].type
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v_size = value_type.sizeof
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data_ptr = (ptr + t_size - v_size).cast(value_type.pointer()).dereference()
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return [('Some', data_ptr)]
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return [('None', None)]
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def to_string(self):
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return None
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# Useful for debugging when type is unknown
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class TestPrinter:
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def __init__(self, val):
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self.val = val
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def to_string(self):
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return "[UNKNOWN - type = {0}]".format(str(self.val.type))
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type_map = [
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('struct Au', AuPrinter),
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('FlowFlags', BitFieldU8Printer),
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('IntrinsicWidths', ChildPrinter),
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('PlacementInfo', ChildPrinter),
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('TrustedNodeAddress', TrustedNodeAddressPrinter),
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('NodeTypeId', NodeTypeIdPrinter),
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('Option', OptionPrinter),
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]
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def lookup_servo_type(val):
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val_type = str(val.type)
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for (type_name, printer) in type_map:
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if val_type == type_name or val_type.endswith("::" + type_name):
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return printer(val)
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return None
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# return TestPrinter(val)
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def register_printers(obj):
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gdb.pretty_printers.append(lookup_servo_type)
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