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