lldb/examples/summaries/cocoa/NSURL.py

"""
LLDB AppKit formatters

Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
See https://llvm.org/LICENSE.txt for license information.
SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
"""
# summary provider for NSURL
import lldb
import ctypes
import lldb.runtime.objc.objc_runtime
import lldb.formatters.metrics
import CFString
import lldb.formatters.Logger

statistics = lldb.formatters.metrics.Metrics()
statistics.add_metric('invalid_isa')
statistics.add_metric('invalid_pointer')
statistics.add_metric('unknown_class')
statistics.add_metric('code_notrun')

# despite the similary to synthetic children providers, these classes are not
# trying to provide anything but a summary for an NSURL, so they need not
# obey the interface specification for synthetic children providers


class NSURLKnown_SummaryProvider:

    def adjust_for_architecture(self):
        pass

    def __init__(self, valobj, params):
        logger = lldb.formatters.Logger.Logger()
        self.valobj = valobj
        self.sys_params = params
        if not(self.sys_params.types_cache.NSString):
            self.sys_params.types_cache.NSString = self.valobj.GetTarget(
            ).FindFirstType('NSString').GetPointerType()
        if not(self.sys_params.types_cache.NSURL):
            self.sys_params.types_cache.NSURL = self.valobj.GetTarget(
            ).FindFirstType('NSURL').GetPointerType()
        self.update()

    def update(self):
        logger = lldb.formatters.Logger.Logger()
        self.adjust_for_architecture()

    # one pointer is the ISA
    # then there is one more pointer and 8 bytes of plain data
    # (which are also present on a 32-bit system)
    # then there is a pointer to an NSString which is the url text
    # optionally, the next pointer is another NSURL which is the "base"
    # of this one when doing NSURLs composition (incidentally, NSURLs can
    # recurse the base+text mechanism to any desired depth)
    def offset_text(self):
        logger = lldb.formatters.Logger.Logger()
        return 24 if self.sys_params.is_64_bit else 16

    def offset_base(self):
        logger = lldb.formatters.Logger.Logger()
        return self.offset_text() + self.sys_params.pointer_size

    def url_text(self):
        logger = lldb.formatters.Logger.Logger()
        text = self.valobj.CreateChildAtOffset(
            "text", self.offset_text(), self.sys_params.types_cache.NSString)
        base = self.valobj.CreateChildAtOffset(
            "base", self.offset_base(), self.sys_params.types_cache.NSURL)
        my_string = CFString.CFString_SummaryProvider(text, None)
        if len(my_string) > 0 and base.GetValueAsUnsigned(0) != 0:
            # remove final " from myself
            my_string = my_string[0:len(my_string) - 1]
            my_string = my_string + ' -- '
            my_base_string = NSURL_SummaryProvider(base, None)
            if len(my_base_string) > 2:
                # remove @" marker from base URL string
                my_base_string = my_base_string[2:]
            my_string = my_string + my_base_string
        return my_string


class NSURLUnknown_SummaryProvider:

    def adjust_for_architecture(self):
        pass

    def __init__(self, valobj, params):
        logger = lldb.formatters.Logger.Logger()
        self.valobj = valobj
        self.sys_params = params
        self.update()

    def update(self):
        logger = lldb.formatters.Logger.Logger()
        self.adjust_for_architecture()

    def url_text(self):
        logger = lldb.formatters.Logger.Logger()
        stream = lldb.SBStream()
        self.valobj.GetExpressionPath(stream)
        url_text_vo = self.valobj.CreateValueFromExpression(
            "url", "(NSString*)[" + stream.GetData() + " description]")
        if url_text_vo.IsValid():
            return CFString.CFString_SummaryProvider(url_text_vo, None)
        return '<variable is not NSURL>'


def GetSummary_Impl(valobj):
    logger = lldb.formatters.Logger.Logger()
    global statistics
    class_data, wrapper = lldb.runtime.objc.objc_runtime.Utilities.prepare_class_detection(
        valobj, statistics)
    if wrapper:
        return wrapper

    name_string = class_data.class_name()
    logger >> "class name is: " + str(name_string)

    if name_string == 'NSURL':
        wrapper = NSURLKnown_SummaryProvider(valobj, class_data.sys_params)
        statistics.metric_hit('code_notrun', valobj)
    else:
        wrapper = NSURLUnknown_SummaryProvider(valobj, class_data.sys_params)
        statistics.metric_hit(
            'unknown_class',
            valobj.GetName() +
            " seen as " +
            name_string)
    return wrapper


def NSURL_SummaryProvider(valobj, dict):
    logger = lldb.formatters.Logger.Logger()
    provider = GetSummary_Impl(valobj)
    if provider is not None:
        if isinstance(
                provider,
                lldb.runtime.objc.objc_runtime.SpecialSituation_Description):
            return provider.message()
        try:
            summary = provider.url_text()
        except:
            summary = None
        logger >> "got summary " + str(summary)
        if summary is None or summary == '':
            summary = '<variable is not NSURL>'
        return summary
    return 'Summary Unavailable'


def __lldb_init_module(debugger, dict):
    debugger.HandleCommand(
        "type summary add -F NSURL.NSURL_SummaryProvider NSURL CFURLRef")