xref: /llvm-project/lldb/examples/summaries/cocoa/NSData.py (revision 2238dcc39358353cac21df75c3c3286ab20b8f53)
1"""
2LLDB AppKit formatters
3
4Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5See https://llvm.org/LICENSE.txt for license information.
6SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7"""
8# example summary provider for NSData
9# the real summary is now C++ code built into LLDB
10import lldb
11import ctypes
12import lldb.runtime.objc.objc_runtime
13import lldb.formatters.metrics
14import lldb.formatters.Logger
15
16statistics = lldb.formatters.metrics.Metrics()
17statistics.add_metric("invalid_isa")
18statistics.add_metric("invalid_pointer")
19statistics.add_metric("unknown_class")
20statistics.add_metric("code_notrun")
21
22# despite the similary to synthetic children providers, these classes are not
23# trying to provide anything but the length for an NSData, so they need not
24# obey the interface specification for synthetic children providers
25
26
27class NSConcreteData_SummaryProvider:
28    def adjust_for_architecture(self):
29        pass
30
31    def __init__(self, valobj, params):
32        logger = lldb.formatters.Logger.Logger()
33        logger >> "NSConcreteData_SummaryProvider __init__"
34        self.valobj = valobj
35        self.sys_params = params
36        if not (self.sys_params.types_cache.NSUInteger):
37            if self.sys_params.is_64_bit:
38                self.sys_params.types_cache.NSUInteger = (
39                    self.valobj.GetType().GetBasicType(lldb.eBasicTypeUnsignedLong)
40                )
41            else:
42                self.sys_params.types_cache.NSUInteger = (
43                    self.valobj.GetType().GetBasicType(lldb.eBasicTypeUnsignedInt)
44                )
45        self.update()
46
47    def update(self):
48        self.adjust_for_architecture()
49
50    # one pointer is the ISA
51    # then there are 32 bit worth of flags and other data
52    # however, on 64bit systems these are padded to be a full
53    # machine word long, which means we actually have two pointers
54    # worth of data to skip
55    def offset(self):
56        return 2 * self.sys_params.pointer_size
57
58    def length(self):
59        logger = lldb.formatters.Logger.Logger()
60        logger >> "NSConcreteData_SummaryProvider length"
61        size = self.valobj.CreateChildAtOffset(
62            "count", self.offset(), self.sys_params.types_cache.NSUInteger
63        )
64        logger >> str(size)
65        logger >> str(size.GetValueAsUnsigned(0))
66        return size.GetValueAsUnsigned(0)
67
68
69class NSDataUnknown_SummaryProvider:
70    def adjust_for_architecture(self):
71        pass
72
73    def __init__(self, valobj, params):
74        logger = lldb.formatters.Logger.Logger()
75        logger >> "NSDataUnknown_SummaryProvider __init__"
76        self.valobj = valobj
77        self.sys_params = params
78        self.update()
79
80    def update(self):
81        self.adjust_for_architecture()
82
83    def length(self):
84        logger = lldb.formatters.Logger.Logger()
85        logger >> "NSDataUnknown_SummaryProvider length"
86        stream = lldb.SBStream()
87        self.valobj.GetExpressionPath(stream)
88        logger >> stream.GetData()
89        num_children_vo = self.valobj.CreateValueFromExpression(
90            "count", "(int)[" + stream.GetData() + " length]"
91        )
92        logger >> "still in after expression: " + str(num_children_vo)
93        if num_children_vo.IsValid():
94            logger >> "wow - expr output is valid: " + str(
95                num_children_vo.GetValueAsUnsigned()
96            )
97            return num_children_vo.GetValueAsUnsigned(0)
98        logger >> "invalid expr output - too bad"
99        return "<variable is not NSData>"
100
101
102def GetSummary_Impl(valobj):
103    global statistics
104    logger = lldb.formatters.Logger.Logger()
105    logger >> "NSData GetSummary_Impl"
106    (
107        class_data,
108        wrapper,
109    ) = lldb.runtime.objc.objc_runtime.Utilities.prepare_class_detection(
110        valobj, statistics
111    )
112    if wrapper:
113        logger >> "got a wrapper summary - using it"
114        return wrapper
115
116    name_string = class_data.class_name()
117    logger >> "class name: " + name_string
118    if (
119        name_string == "NSConcreteData"
120        or name_string == "NSConcreteMutableData"
121        or name_string == "__NSCFData"
122    ):
123        wrapper = NSConcreteData_SummaryProvider(valobj, class_data.sys_params)
124        statistics.metric_hit("code_notrun", valobj)
125    else:
126        wrapper = NSDataUnknown_SummaryProvider(valobj, class_data.sys_params)
127        statistics.metric_hit(
128            "unknown_class", valobj.GetName() + " seen as " + name_string
129        )
130    return wrapper
131
132
133def NSData_SummaryProvider(valobj, dict):
134    logger = lldb.formatters.Logger.Logger()
135    logger >> "NSData_SummaryProvider"
136    provider = GetSummary_Impl(valobj)
137    logger >> "found a summary provider, it is: " + str(provider)
138    if provider is not None:
139        try:
140            summary = provider.length()
141        except:
142            summary = None
143        logger >> "got a summary: it is " + str(summary)
144        if summary is None:
145            summary = "<variable is not NSData>"
146        elif isinstance(summary, str):
147            pass
148        else:
149            if summary == 1:
150                summary = "1 byte"
151            else:
152                summary = str(summary) + " bytes"
153        return summary
154    return "Summary Unavailable"
155
156
157def NSData_SummaryProvider2(valobj, dict):
158    logger = lldb.formatters.Logger.Logger()
159    logger >> "NSData_SummaryProvider2"
160    provider = GetSummary_Impl(valobj)
161    logger >> "found a summary provider, it is: " + str(provider)
162    if provider is not None:
163        if isinstance(
164            provider, lldb.runtime.objc.objc_runtime.SpecialSituation_Description
165        ):
166            return provider.message()
167        try:
168            summary = provider.length()
169        except:
170            summary = None
171        logger >> "got a summary: it is " + str(summary)
172        if summary is None:
173            summary = "<variable is not CFData>"
174        elif isinstance(summary, str):
175            pass
176        else:
177            if summary == 1:
178                summary = '@"1 byte"'
179            else:
180                summary = '@"' + str(summary) + ' bytes"'
181        return summary
182    return "Summary Unavailable"
183
184
185def __lldb_init_module(debugger, dict):
186    debugger.HandleCommand("type summary add -F NSData.NSData_SummaryProvider NSData")
187    debugger.HandleCommand(
188        "type summary add -F NSData.NSData_SummaryProvider2 CFDataRef CFMutableDataRef"
189    )
190