[Qemu-devel] [PATCH v5 2/5] Modified the tracetool framework for LTTng 2.x

[Mohamad Gebai]

* A new format is required to generate definitions for ust tracepoints.
  Files ust_events_h.py and ust_events_c.py define common macros, while
  new function ust_events_h in events.py does the actual definition of
  each tracepoint.
* ust.py generates the new interface for calling userspace tracepoints
  with LTTng 2.x, replacing trace_name(args) to tracepoint(name, args).
* As explained in ust_events_c.py, -Wredundant-decls gives a warning
  when compiling with gcc 4.7 or older. This is specific to lttng-ust so
  for now use a pragma clause to avoid getting a warning.

Signed-off-by: Mohamad Gebai <address@hidden>
Reviewed-by: Alex Bennée <address@hidden>
---
 scripts/tracetool/backend/events.py      | 44 +++++++++++++++++
 scripts/tracetool/backend/ust.py         | 82 +++++++-------------------------
 scripts/tracetool/format/ust_events_c.py | 30 ++++++++++++
 scripts/tracetool/format/ust_events_h.py | 57 ++++++++++++++++++++++
 4 files changed, 147 insertions(+), 66 deletions(-)
 create mode 100644 scripts/tracetool/format/ust_events_c.py
 create mode 100644 scripts/tracetool/format/ust_events_h.py

diff --git a/scripts/tracetool/backend/events.py 
b/scripts/tracetool/backend/events.py
index 5afce3e..1691c90 100644
--- a/scripts/tracetool/backend/events.py
+++ b/scripts/tracetool/backend/events.py
@@ -6,6 +6,8 @@ Generic event description.
 
 This is a dummy backend to establish appropriate frontend/backend compatibility
 checks.
+
+Generates tracepoint definitions for LTTng userspace tracing when using ust as 
a backend.
 """
 
 __author__     = "Lluís Vilanova <address@hidden>"
@@ -16,8 +18,50 @@ __maintainer__ = "Stefan Hajnoczi"
 __email__      = "address@hidden"
 
 
+from tracetool import out
+
 def events_h(events):
     pass
 
 def events_c(events):
     pass
+
+def ust_events_c(events):
+    pass
+
+def ust_events_h(events):
+    for e in events:
+        if len(e.args) > 0:
+            out('TRACEPOINT_EVENT(',
+                '   qemu,',
+                '   %(name)s,',
+                '   TP_ARGS(%(args)s),',
+                '   TP_FIELDS(',
+                name = e.name,
+                args = ", ".join(", ".join(i) for i in e.args),
+                )
+
+            for t,n in e.args:
+                if ('int' in t) or ('long' in t) or ('unsigned' in t) or 
('size_t' in t):
+                    out('       ctf_integer(' + t + ', ' + n + ', ' + n + ')')
+                elif ('double' in t) or ('float' in t):
+                    out('       ctf_float(' + t + ', ' + n + ', ' + n + ')')
+                elif ('char *' in t) or ('char*' in t):
+                    out('       ctf_string(' + n + ', ' + n + ')')
+                elif ('void *' in t) or ('void*' in t):
+                    out('       ctf_integer_hex(unsigned long, ' + n + ', ' + 
n + ')')
+
+            out('   )',
+                ')',
+                '')
+
+        else:
+            out('TRACEPOINT_EVENT(',
+                '   qemu,',
+                '   %(name)s,',
+                '   TP_ARGS(void),',
+                '   TP_FIELDS()',
+                ')',
+                '',
+                name = e.name,
+                )
diff --git a/scripts/tracetool/backend/ust.py b/scripts/tracetool/backend/ust.py
index ea36995..10c0875 100644
--- a/scripts/tracetool/backend/ust.py
+++ b/scripts/tracetool/backend/ust.py
@@ -18,76 +18,26 @@ from tracetool import out
 
 PUBLIC = True
 
-
 def c(events):
-    out('#include <ust/marker.h>',
-        '#undef mutex_lock',
-        '#undef mutex_unlock',
-        '#undef inline',
-        '#undef wmb',
-        '#include "trace.h"')
+    pass
+
 
+def h(events):
+    out('#include <lttng/tracepoint.h>',
+        '#include "trace/generated-ust-provider.h"',
+        '')
     for e in events:
         argnames = ", ".join(e.args.names())
         if len(e.args) > 0:
-            argnames = ', ' + argnames
-
-            out('DEFINE_TRACE(ust_%(name)s);',
-                '',
-                'static void ust_%(name)s_probe(%(args)s)',
-                '{',
-                '    trace_mark(ust, %(name)s, %(fmt)s%(argnames)s);',
-                '}',
-                name = e.name,
-                args = e.args,
-                fmt = e.fmt,
-                argnames = argnames,
-                )
-
-        else:
-            out('DEFINE_TRACE(ust_%(name)s);',
-                '',
-                'static void ust_%(name)s_probe(%(args)s)',
-                '{',
-                '    trace_mark(ust, %(name)s, UST_MARKER_NOARGS);',
-                '}',
-                name = e.name,
-                args = e.args,
-                )
-
-    # register probes
-    out('',
-        'static void __attribute__((constructor)) trace_init(void)',
-        '{')
-
-    for e in events:
-        out('    register_trace_ust_%(name)s(ust_%(name)s_probe);',
+            argnames = ", " + argnames
+
+        out('static inline void trace_%(name)s(%(args)s)',
+            '{',
+            '    tracepoint(qemu, %(name)s%(tp_args)s);'
+            '',
+            '}',
+            '',
             name = e.name,
+            args = e.args,
+            tp_args = argnames,
             )
-
-    out('}')
-
-
-def h(events):
-    out('#include <ust/tracepoint.h>',
-        '#undef mutex_lock',
-        '#undef mutex_unlock',
-        '#undef inline',
-        '#undef wmb')
-
-    for e in events:
-        if len(e.args) > 0:
-            out('DECLARE_TRACE(ust_%(name)s, TP_PROTO(%(args)s), 
TP_ARGS(%(argnames)s));',
-                '#define trace_%(name)s trace_ust_%(name)s',
-                name = e.name,
-                args = e.args,
-                argnames = ", ".join(e.args.names()),
-                )
-
-        else:
-            out('_DECLARE_TRACEPOINT_NOARGS(ust_%(name)s);',
-                '#define trace_%(name)s trace_ust_%(name)s',
-                name = e.name,
-                )
-
-    out()
diff --git a/scripts/tracetool/format/ust_events_c.py 
b/scripts/tracetool/format/ust_events_c.py
new file mode 100644
index 0000000..71328f3
--- /dev/null
+++ b/scripts/tracetool/format/ust_events_c.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Generate .c for LTTng ust event description.
+"""
+
+__author__     = "Lluís Vilanova <address@hidden>"
+__copyright__  = "Copyright 2012, Lluís Vilanova <address@hidden>"
+__license__    = "GPL version 2 or (at your option) any later version"
+
+__maintainer__ = "Stefan Hajnoczi"
+__email__      = "address@hidden"
+
+
+from tracetool import out
+
+
+def begin(events):
+    out('/* This file is autogenerated by tracetool, do not edit. */',
+        '',
+        '#define TRACEPOINT_DEFINE',
+        '#define TRACEPOINT_CREATE_PROBES',
+        '',
+        '/* If gcc version 4.7 or older is used, LTTng ust gives a warning 
when compiling with',
+        '   -Wredundant-decls.',
+        ' */',
+        '#pragma GCC diagnostic ignored "-Wredundant-decls"',
+        '',
+        '#include "generated-ust-provider.h"')
diff --git a/scripts/tracetool/format/ust_events_h.py 
b/scripts/tracetool/format/ust_events_h.py
new file mode 100644
index 0000000..b8e3de1
--- /dev/null
+++ b/scripts/tracetool/format/ust_events_h.py
@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Generate .h for LTTng ust event description.
+"""
+
+__author__     = "Lluís Vilanova <address@hidden>"
+__copyright__  = "Copyright 2012, Lluís Vilanova <address@hidden>"
+__license__    = "GPL version 2 or (at your option) any later version"
+
+__maintainer__ = "Stefan Hajnoczi"
+__email__      = "address@hidden"
+
+
+from tracetool import out
+
+
+def begin(events):
+    out('/* This file is autogenerated by tracetool, do not edit. */',
+        '',
+        '#undef TRACEPOINT_PROVIDER',
+        '#define TRACEPOINT_PROVIDER qemu',
+        '',
+        '#undef TRACEPOINT_INCLUDE_FILE',
+        '#define TRACEPOINT_INCLUDE_FILE ./generated-ust-provider.h',
+        '',
+        '#if !defined (TRACE__GENERATED_UST_H) || 
defined(TRACEPOINT_HEADER_MULTI_READ)',
+        '#define TRACE__GENERATED_UST_H',
+        '',
+        '#include "qemu-common.h"',
+        '#include <lttng/tracepoint.h>',
+        '',
+        '/*',
+        ' * LTTng ust 2.0 does not allow you to use TP_ARGS(void) for 
tracepoints',
+        ' * requiring no arguments. We define these macros introduced in more 
recent'
+        ' * versions of LTTng ust as a workaround',
+        ' */',
+        '#ifndef _TP_EXPROTO1',
+        '#define _TP_EXPROTO1(a)               void',
+        '#endif',
+        '#ifndef _TP_EXDATA_PROTO1',
+        '#define _TP_EXDATA_PROTO1(a)          void *__tp_data',
+        '#endif',
+        '#ifndef _TP_EXDATA_VAR1',
+        '#define _TP_EXDATA_VAR1(a)            __tp_data',
+        '#endif',
+        '#ifndef _TP_EXVAR1',
+        '#define _TP_EXVAR1(a)',
+        '#endif',
+        '')
+
+def end(events):
+    out('#endif /* TRACE__GENERATED_UST_H */',
+        '',
+        '/* This part must be outside ifdef protection */',
+        '#include <lttng/tracepoint-event.h>')
-- 
1.8.4.rc3