tracetool: Add support for the 'dtrace' backend

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

scripts/tracetool/backend/dtrace.py

@@ -0,0 +1,97 @@
+#!/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-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('',
+        '};')
+
+
+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():
+                # 'limit' is a reserved keyword
+                if name == 'limit':
+                    name = '_limit'
+                out('  %s = $arg%d;' % (name.lstrip(), i))
+                i += 1
+
+        out('}')
+
+    out()