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.py

@@ -44,6 +44,11 @@ Options:
     --help                   This help message.
     --list-backends          Print list of available backends.
     --check-backend          Check if the given backend is valid.
+    --binary <path>          Full path to QEMU binary.
+    --target-type <type>     QEMU emulator target type ('system' or 'user').
+    --target-arch <arch>     QEMU emulator target arch.
+    --probe-prefix <prefix>  Prefix for dtrace probe names
+                             (default: qemu-<target-type>-<target-arch>).\
 """ % {
             "script" : _SCRIPT,
             "backends" : backend_descr,
@@ -71,6 +76,10 @@ def main(args):
     check_backend = False
     arg_backend = ""
     arg_format = ""
+    binary = None
+    target_type = None
+    target_arch = None
+    probe_prefix = None
     for opt, arg in opts:
         if opt == "--help":
             error_opt()
@@ -87,6 +96,15 @@ def main(args):
         elif opt == "--check-backend":
             check_backend = True
 
+        elif opt == "--binary":
+            binary = arg
+        elif opt == '--target-type':
+            target_type = arg
+        elif opt == '--target-arch':
+            target_arch = arg
+        elif opt == '--probe-prefix':
+            probe_prefix = arg
+
         else:
             error_opt("unhandled option: %s" % opt)
 
@@ -99,8 +117,20 @@ def main(args):
         else:
             sys.exit(1)
 
+    if arg_format == "stap":
+        if binary is None:
+            error_opt("--binary is required for SystemTAP tapset generator")
+        if probe_prefix is None and target_type is None:
+            error_opt("--target-type is required for SystemTAP tapset generator")
+        if probe_prefix is None and target_arch is None:
+            error_opt("--target-arch is required for SystemTAP tapset generator")
+
+        if probe_prefix is None:
+            probe_prefix = ".".join([ "qemu", target_type, target_arch ])
+
     try:
-        tracetool.generate(sys.stdin, arg_format, arg_backend)
+        tracetool.generate(sys.stdin, arg_format, arg_backend,
+                           binary = binary, probe_prefix = probe_prefix)
     except tracetool.TracetoolError as e:
         error_opt(str(e))
 

scripts/tracetool/__init__.py

@@ -212,7 +212,8 @@ def try_import(mod_name, attr_name = None, attr_default = None):
         return False, None
 
 
-def generate(fevents, format, backend):
+def generate(fevents, format, backend,
+             binary = None, probe_prefix = None):
     """Generate the output for the given (format, backend) pair.
 
     Parameters
@@ -223,6 +224,10 @@ def generate(fevents, format, backend):
         Output format name.
     backend : str
         Output backend name.
+    binary : str or None
+        See tracetool.backend.dtrace.BINARY.
+    probe_prefix : str or None
+        See tracetool.backend.dtrace.PROBEPREFIX.
     """
     # fix strange python error (UnboundLocalError tracetool)
     import tracetool
@@ -245,6 +250,10 @@ def generate(fevents, format, backend):
         raise TracetoolError("backend '%s' not compatible with format '%s'" %
                              (backend, format))
 
+    import tracetool.backend.dtrace
+    tracetool.backend.dtrace.BINARY = binary
+    tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
+
     events = _read_events(fevents)
 
     if backend == "nop":

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()

scripts/tracetool/format/d.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Generate .d file (DTrace only).
+"""
+
+__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
+
+
+def begin(events):
+    out('/* This file is autogenerated by tracetool, do not edit. */')

scripts/tracetool/format/stap.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Generate .stp file (DTrace with SystemTAP only).
+"""
+
+__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
+
+
+def begin(events):
+    out('/* This file is autogenerated by tracetool, do not edit. */')