scripts/tracetool/backend/simple.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 """
   5 Simple built-in backend.
   6 """
   7
   8 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
   9 __copyright__  = "Copyright 2012-2014, 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 PUBLIC = True
  20
  21
  22 def is_string(arg):
  23     strtype = ('const char*', 'char*', 'const char *', 'char *')
  24     if arg.lstrip().startswith(strtype):
  25         return True
  26     else:
  27         return False
  28
  29
  30 def generate_h_begin(events):
  31     for event in events:
  32         out('void _simple_%(api)s(%(args)s);',
  33             api=event.api(),
  34             args=event.args)
  35     out('')
  36
  37
  38 def generate_h(event):
  39     out('    _simple_%(api)s(%(args)s);',
  40         api=event.api(),
  41         args=", ".join(event.args.names()))
  42
  43
  44 def generate_c_begin(events):
  45     out('#include "trace.h"',
  46         '#include "trace/control.h"',
  47         '#include "trace/simple.h"',
  48         '')
  49
  50
  51 def generate_c(event):
  52     out('void _simple_%(api)s(%(args)s)',
  53         '{',
  54         '    TraceBufferRecord rec;',
  55         api=event.api(),
  56         args=event.args)
  57     sizes = []
  58     for type_, name in event.args:
  59         if is_string(type_):
  60             out('    size_t arg%(name)s_len = %(name)s ? MIN(strlen(%(name)s), MAX_TRACE_STRLEN) : 0;',
  61                 name=name)
  62             strsizeinfo = "4 + arg%s_len" % name
  63             sizes.append(strsizeinfo)
  64         else:
  65             sizes.append("8")
  66     sizestr = " + ".join(sizes)
  67     if len(event.args) == 0:
  68         sizestr = '0'
  69
  70
  71     out('',
  72         '    if (!trace_event_get_state(%(event_id)s)) {',
  73         '        return;',
  74         '    }',
  75         '',
  76         '    if (trace_record_start(&rec, %(event_id)s, %(size_str)s)) {',
  77         '        return; /* Trace Buffer Full, Event Dropped ! */',
  78         '    }',
  79         event_id='TRACE_' + event.name.upper(),
  80         size_str=sizestr)
  81
  82     if len(event.args) > 0:
  83         for type_, name in event.args:
  84             # string
  85             if is_string(type_):
  86                 out('    trace_record_write_str(&rec, %(name)s, arg%(name)s_len);',
  87                     name=name)
  88             # pointer var (not string)
  89             elif type_.endswith('*'):
  90                 out('    trace_record_write_u64(&rec, (uintptr_t)(uint64_t *)%(name)s);',
  91                     name=name)
  92             # primitive data type
  93             else:
  94                 out('    trace_record_write_u64(&rec, (uint64_t)%(name)s);',
  95                    name=name)
  96
  97     out('    trace_record_finish(&rec);',
  98         '}',
  99         '')