scripts/tracetool/backend/dtrace.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 """
   5 DTrace/SystemTAP backend.
   6 """
   7
   8 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
   9 __copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
  10 __license__    = "GPL version 2 or (at your option) any later version"
  11
  12 __maintainer__ = "Stefan Hajnoczi"
  13 __email__      = "stefanha@linux.vnet.ibm.com"
  14
  15
  16 from tracetool import out
  17
  18
  19 PROBEPREFIX = None
  20
  21 def _probeprefix():
  22     if PROBEPREFIX is None:
  23         raise ValueError("you must set PROBEPREFIX")
  24     return PROBEPREFIX
  25
  26
  27 BINARY = None
  28
  29 def _binary():
  30     if BINARY is None:
  31         raise ValueError("you must set BINARY")
  32     return BINARY
  33
  34
  35 def c(events):
  36     pass
  37
  38
  39 def h(events):
  40     out('#include "trace-dtrace.h"',
  41         '')
  42
  43     for e in events:
  44         out('static inline void trace_%(name)s(%(args)s) {',
  45             '    QEMU_%(uppername)s(%(argnames)s);',
  46             '}',
  47             name = e.name,
  48             args = e.args,
  49             uppername = e.name.upper(),
  50             argnames = ", ".join(e.args.names()),
  51             )
  52
  53
  54 def d(events):
  55     out('provider qemu {')
  56
  57     for e in events:
  58         args = str(e.args)
  59
  60         # DTrace provider syntax expects foo() for empty
  61         # params, not foo(void)
  62         if args == 'void':
  63             args = ''
  64
  65         # Define prototype for probe arguments
  66         out('',
  67             'probe %(name)s(%(args)s);',
  68             name = e.name,
  69             args = args,
  70             )
  71
  72     out('',
  73         '};')
  74
  75
  76 # Technically 'self' is not used by systemtap yet, but
  77 # they recommended we keep it in the reserved list anyway
  78 RESERVED_WORDS = (
  79     'break', 'catch', 'continue', 'delete', 'else', 'for',
  80     'foreach', 'function', 'global', 'if', 'in', 'limit',
  81     'long', 'next', 'probe', 'return', 'self', 'string',
  82     'try', 'while'
  83     )
  84
  85 def stap(events):
  86     for e in events:
  87         # Define prototype for probe arguments
  88         out('probe %(probeprefix)s.%(name)s = process("%(binary)s").mark("%(name)s")',
  89             '{',
  90             probeprefix = _probeprefix(),
  91             name = e.name,
  92             binary = _binary(),
  93             )
  94
  95         i = 1
  96         if len(e.args) > 0:
  97             for name in e.args.names():
  98                 # Append underscore to reserved keywords
  99                 if name in RESERVED_WORDS:
 100                     name += '_'
 101                 out('  %s = $arg%d;' % (name, i))
 102                 i += 1
 103
 104         out('}')
 105
 106     out()