lldb/examples/python/jump.py

   1 import lldb
   2 import re
   3
   4
   5 def parse_linespec(linespec, frame, result):
   6     """Handles a subset of GDB-style linespecs.  Specifically:
   7
   8     number           - A line in the current file
   9     +offset          - The line /offset/ lines after this line
  10     -offset          - The line /offset/ lines before this line
  11     filename:number  - Line /number/ in file /filename/
  12     function         - The start of /function/
  13     *address         - The pointer target of /address/, which must be a literal (but see `` in LLDB)
  14
  15     We explicitly do not handle filename:function because it is ambiguous in Objective-C.
  16
  17     This function returns a list of addresses."""
  18
  19     breakpoint = None
  20     target = frame.GetThread().GetProcess().GetTarget()
  21
  22     matched = False
  23
  24     if not matched:
  25         mo = re.match("^([0-9]+)$", linespec)
  26         if mo is not None:
  27             matched = True
  28             # print "Matched <linenum>"
  29             line_number = int(mo.group(1))
  30             line_entry = frame.GetLineEntry()
  31             if not line_entry.IsValid():
  32                 result.AppendMessage(
  33                     "Specified a line in the current file, but the current frame doesn't have line table information."
  34                 )
  35                 return
  36             breakpoint = target.BreakpointCreateByLocation(
  37                 line_entry.GetFileSpec(), line_number
  38             )
  39
  40     if not matched:
  41         mo = re.match("^\+([0-9]+)$", linespec)
  42         if mo is not None:
  43             matched = True
  44             # print "Matched +<count>"
  45             line_number = int(mo.group(1))
  46             line_entry = frame.GetLineEntry()
  47             if not line_entry.IsValid():
  48                 result.AppendMessage(
  49                     "Specified a line in the current file, but the current frame doesn't have line table information."
  50                 )
  51                 return
  52             breakpoint = target.BreakpointCreateByLocation(
  53                 line_entry.GetFileSpec(), (line_entry.GetLine() + line_number)
  54             )
  55
  56     if not matched:
  57         mo = re.match("^\-([0-9]+)$", linespec)
  58         if mo is not None:
  59             matched = True
  60             # print "Matched -<count>"
  61             line_number = int(mo.group(1))
  62             line_entry = frame.GetLineEntry()
  63             if not line_entry.IsValid():
  64                 result.AppendMessage(
  65                     "Specified a line in the current file, but the current frame doesn't have line table information."
  66                 )
  67                 return
  68             breakpoint = target.BreakpointCreateByLocation(
  69                 line_entry.GetFileSpec(), (line_entry.GetLine() - line_number)
  70             )
  71
  72     if not matched:
  73         mo = re.match("^(.*):([0-9]+)$", linespec)
  74         if mo is not None:
  75             matched = True
  76             # print "Matched <filename>:<linenum>"
  77             file_name = mo.group(1)
  78             line_number = int(mo.group(2))
  79             breakpoint = target.BreakpointCreateByLocation(file_name, line_number)
  80
  81     if not matched:
  82         mo = re.match("\*((0x)?([0-9a-f]+))$", linespec)
  83         if mo is not None:
  84             matched = True
  85             # print "Matched <address-expression>"
  86             address = int(mo.group(1), base=0)
  87             breakpoint = target.BreakpointCreateByAddress(address)
  88
  89     if not matched:
  90         # print "Trying <function-name>"
  91         breakpoint = target.BreakpointCreateByName(linespec)
  92
  93     num_locations = breakpoint.GetNumLocations()
  94
  95     if num_locations == 0:
  96         result.AppendMessage(
  97             "The line specification provided doesn't resolve to any addresses."
  98         )
  99
 100     addr_list = []
 101
 102     for location_index in range(num_locations):
 103         location = breakpoint.GetLocationAtIndex(location_index)
 104         addr_list.append(location.GetAddress())
 105
 106     target.BreakpointDelete(breakpoint.GetID())
 107
 108     return addr_list
 109
 110
 111 def usage_string():
 112     return """   Sets the program counter to a specific address.
 113
 114 Syntax: jump <linespec> [<location-id>]
 115
 116 Command Options Usage:
 117   jump <linenum>
 118   jump +<count>
 119   jump -<count>
 120   jump <filename>:<linenum>
 121   jump <function-name>
 122   jump *<address-expression>
 123
 124 <location-id> serves to disambiguate when multiple locations could be meant."""
 125
 126
 127 def jump(debugger, command, result, internal_dict):
 128     if command == "":
 129         result.AppendMessage(usage_string())
 130
 131     args = command.split()
 132
 133     if not debugger.IsValid():
 134         result.AppendMessage("Invalid debugger!")
 135         return
 136
 137     target = debugger.GetSelectedTarget()
 138     if not target.IsValid():
 139         result.AppendMessage("jump requires a valid target.")
 140         return
 141
 142     process = target.GetProcess()
 143     if not process.IsValid():
 144         result.AppendMessage("jump requires a valid process.")
 145         return
 146
 147     thread = process.GetSelectedThread()
 148     if not thread.IsValid():
 149         result.AppendMessage("jump requires a valid thread.")
 150         return
 151
 152     frame = thread.GetSelectedFrame()
 153     if not frame.IsValid():
 154         result.AppendMessage("jump requires a valid frame.")
 155         return
 156
 157     addresses = parse_linespec(args[0], frame, result)
 158
 159     stream = lldb.SBStream()
 160
 161     if len(addresses) == 0:
 162         return
 163
 164     desired_address = addresses[0]
 165
 166     if len(addresses) > 1:
 167         if len(args) == 2:
 168             desired_index = int(args[1])
 169             if (desired_index >= 0) and (desired_index < len(addresses)):
 170                 desired_address = addresses[desired_index]
 171             else:
 172                 result.AppendMessage(
 173                     "Desired index " + args[1] + " is not one of the options."
 174                 )
 175                 return
 176         else:
 177             index = 0
 178             result.AppendMessage("The specified location resolves to multiple targets.")
 179             for address in addresses:
 180                 stream.Clear()
 181                 address.GetDescription(stream)
 182                 result.AppendMessage(
 183                     "  Location ID " + str(index) + ": " + stream.GetData()
 184                 )
 185                 index = index + 1
 186             result.AppendMessage(
 187                 "Please type 'jump " + command + " <location-id>' to choose one."
 188             )
 189             return
 190
 191     frame.SetPC(desired_address.GetLoadAddress(target))
 192
 193
 194 def __lldb_init_module(debugger, internal_dict):
 195     # Module is being run inside the LLDB interpreter
 196     jump.__doc__ = usage_string()
 197     debugger.HandleCommand("command script add -o -f jump.jump jump")
 198     print(
 199         'The "jump" command has been installed, type "help jump" or "jump <ENTER>" for detailed help.'
 200     )