lldb/examples/python/jump.py

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