Archipelago » qemu

#!/usr/bin/env python

# -*- coding: utf-8 -*-

"""

DTrace/SystemTAP backend.

"""

__author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"

__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"

__license__    = "GPL version 2 or (at your option) any later version"

__maintainer__ = "Stefan Hajnoczi"

__email__      = "stefanha@linux.vnet.ibm.com"

from tracetool import out

PROBEPREFIX = None

def _probeprefix():

    if PROBEPREFIX is None:

        raise ValueError("you must set PROBEPREFIX")

    return PROBEPREFIX

BINARY = None

def _binary():

    if BINARY is None:

        raise ValueError("you must set BINARY")

    return BINARY

def c(events):

    pass

def h(events):

    out('#include "trace/generated-tracers-dtrace.h"',

        '')

    for e in events:

        out('static inline void trace_%(name)s(%(args)s) {',

            '    QEMU_%(uppername)s(%(argnames)s);',

            '}',

            name = e.name,

            args = e.args,

            uppername = e.name.upper(),

            argnames = ", ".join(e.args.names()),

            )

def d(events):

    out('provider qemu {')

    for e in events:

        args = str(e.args)

        # DTrace provider syntax expects foo() for empty

        # params, not foo(void)

        if args == 'void':

            args = ''

        # Define prototype for probe arguments

        out('',

            'probe %(name)s(%(args)s);',

            name = e.name,

            args = args,

            )

    out('',

        '};')

# Technically 'self' is not used by systemtap yet, but

# they recommended we keep it in the reserved list anyway

RESERVED_WORDS = (

    'break', 'catch', 'continue', 'delete', 'else', 'for',

    'foreach', 'function', 'global', 'if', 'in', 'limit',

    'long', 'next', 'probe', 'return', 'self', 'string',

    'try', 'while'

    )

def stap(events):

    for e in events:

        # Define prototype for probe arguments

        out('probe %(probeprefix)s.%(name)s = process("%(binary)s").mark("%(name)s")',

            '{',

            probeprefix = _probeprefix(),

            name = e.name,

            binary = _binary(),

            )

        i = 1

        if len(e.args) > 0:

            for name in e.args.names():

                # Append underscore to reserved keywords

                if name in RESERVED_WORDS:

                    name += '_'

                out('  %s = $arg%d;' % (name, i))

                i += 1

        out('}')

    out()