trace: introduce a formal group name for trace events

The declarations in the generated-tracers.h file are
assuming there's only ever going to be one instance
of this header, as they are not namespaced. When we
have one header per event group, if a single source
file needs to include multiple sets of trace events,
the symbols will all clash.

This change thus introduces a '--group NAME' arg to the
'tracetool' program. This will cause all the symbols in
the generated header files to be given a unique namespace.

If no group is given, the group name 'common' is used,
which is suitable for the current usage where there is
only one global trace-events file used for code generation.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 1475588159-30598-21-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

scripts/tracetool.py

@@ -15,6 +15,8 @@
 
 import sys
 import getopt
+import os.path
+import re
 
 from tracetool import error_write, out
 import tracetool.backend
@@ -60,6 +62,15 @@ def error_opt(msg = None):
     else:
         sys.exit(1)
 
+def make_group_name(filename):
+    dirname = os.path.realpath(os.path.dirname(filename))
+    basedir = os.path.join(os.path.dirname(__file__), os.pardir)
+    basedir = os.path.realpath(os.path.abspath(basedir))
+    dirname = dirname[len(basedir) + 1:]
+
+    if dirname == "":
+        return "common"
+    return re.sub(r"/|-", "_", dirname)
 
 def main(args):
     global _SCRIPT
@@ -134,8 +145,10 @@ def main(args):
     with open(args[0], "r") as fh:
         events = tracetool.read_events(fh)
 
+    group = make_group_name(args[0])
+
     try:
-        tracetool.generate(events, arg_format, arg_backends,
+        tracetool.generate(events, group, arg_format, arg_backends,
                            binary=binary, probe_prefix=probe_prefix)
     except tracetool.TracetoolError as e:
         error_opt(str(e))

scripts/tracetool/__init__.py

@@ -364,7 +364,7 @@ def try_import(mod_name, attr_name=None, attr_default=None):
         return False, None
 
 
-def generate(events, format, backends,
+def generate(events, group, format, backends,
              binary=None, probe_prefix=None):
     """Generate the output for the given (format, backends) pair.
 
@@ -372,6 +372,8 @@ def generate(events, format, backends,
     ----------
     events : list
         list of Event objects to generate for
+    group: str
+        Name of the tracing group
     format : str
         Output format name.
     backends : list
@@ -401,4 +403,4 @@ def generate(events, format, backends,
     tracetool.backend.dtrace.BINARY = binary
     tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
 
-    tracetool.format.generate(events, format, backend)
+    tracetool.format.generate(events, format, backend, group)

scripts/tracetool/backend/__init__.py

@@ -113,11 +113,11 @@ def _run_function(self, name, *args, **kwargs):
             if func is not None:
                 func(*args, **kwargs)
 
-    def generate_begin(self, events):
-        self._run_function("generate_%s_begin", events)
+    def generate_begin(self, events, group):
+        self._run_function("generate_%s_begin", events, group)
 
-    def generate(self, event):
-        self._run_function("generate_%s", event)
+    def generate(self, event, group):
+        self._run_function("generate_%s", event, group)
 
-    def generate_end(self, events):
-        self._run_function("generate_%s_end", events)
+    def generate_end(self, events, group):
+        self._run_function("generate_%s_end", events, group)

scripts/tracetool/backend/dtrace.py

@@ -35,12 +35,12 @@ def binary():
     return BINARY
 
 
-def generate_h_begin(events):
+def generate_h_begin(events, group):
     out('#include "trace/generated-tracers-dtrace.h"',
         '')
 
 
-def generate_h(event):
+def generate_h(event, group):
     out('        QEMU_%(uppername)s(%(argnames)s);',
         uppername=event.name.upper(),
         argnames=", ".join(event.args.names()))

scripts/tracetool/backend/ftrace.py

@@ -19,12 +19,12 @@
 PUBLIC = True
 
 
-def generate_h_begin(events):
+def generate_h_begin(events, group):
     out('#include "trace/ftrace.h"',
         '')
 
 
-def generate_h(event):
+def generate_h(event, group):
     argnames = ", ".join(event.args.names())
     if len(event.args) > 0:
         argnames = ", " + argnames

scripts/tracetool/backend/log.py

@@ -19,12 +19,12 @@
 PUBLIC = True
 
 
-def generate_h_begin(events):
+def generate_h_begin(events, group):
     out('#include "qemu/log.h"',
         '')
 
 
-def generate_h(event):
+def generate_h(event, group):
     argnames = ", ".join(event.args.names())
     if len(event.args) > 0:
         argnames = ", " + argnames

scripts/tracetool/backend/simple.py

@@ -27,7 +27,7 @@ def is_string(arg):
         return False
 
 
-def generate_h_begin(events):
+def generate_h_begin(events, group):
     for event in events:
         out('void _simple_%(api)s(%(args)s);',
             api=event.api(),
@@ -35,13 +35,13 @@ def generate_h_begin(events):
     out('')
 
 
-def generate_h(event):
+def generate_h(event, group):
     out('        _simple_%(api)s(%(args)s);',
         api=event.api(),
         args=", ".join(event.args.names()))
 
 
-def generate_c_begin(events):
+def generate_c_begin(events, group):
     out('#include "qemu/osdep.h"',
         '#include "trace.h"',
         '#include "trace/control.h"',
@@ -49,7 +49,7 @@ def generate_c_begin(events):
         '')
 
 
-def generate_c(event):
+def generate_c(event, group):
     out('void _simple_%(api)s(%(args)s)',
         '{',
         '    TraceBufferRecord rec;',

scripts/tracetool/backend/syslog.py

@@ -19,12 +19,12 @@
 PUBLIC = True
 
 
-def generate_h_begin(events):
+def generate_h_begin(events, group):
     out('#include <syslog.h>',
         '')
 
 
-def generate_h(event):
+def generate_h(event, group):
     argnames = ", ".join(event.args.names())
     if len(event.args) > 0:
         argnames = ", " + argnames

scripts/tracetool/backend/ust.py

@@ -19,13 +19,13 @@
 PUBLIC = True
 
 
-def generate_h_begin(events):
+def generate_h_begin(events, group):
     out('#include <lttng/tracepoint.h>',
         '#include "trace/generated-ust-provider.h"',
         '')
 
 
-def generate_h(event):
+def generate_h(event, group):
     argnames = ", ".join(event.args.names())
     if len(event.args) > 0:
         argnames = ", " + argnames

scripts/tracetool/format/__init__.py

@@ -74,7 +74,7 @@ def exists(name):
     return tracetool.try_import("tracetool.format." + name)[1]
 
 
-def generate(events, format, backend):
+def generate(events, format, backend, group):
     if not exists(format):
         raise ValueError("unknown format: %s" % format)
     format = format.replace("-", "_")
@@ -82,4 +82,4 @@ def generate(events, format, backend):
                                 "generate")[1]
     if func is None:
         raise AttributeError("format has no 'generate': %s" % format)
-    func(events, backend)
+    func(events, backend, group)

scripts/tracetool/format/c.py

@@ -16,7 +16,7 @@
 from tracetool import out
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     active_events = [e for e in events
                      if "disable" not in e.properties]
 
@@ -47,7 +47,8 @@ def generate(events, backend):
             sstate = "TRACE_%s_ENABLED" % e.name.upper(),
             dstate = e.api(e.QEMU_DSTATE))
 
-    out('TraceEvent *trace_events[] = {')
+    out('TraceEvent *%(group)s_trace_events[] = {',
+        group = group.lower())
 
     for e in events:
         out('    &%(event)s,', event = e.api(e.QEMU_EVENT))
@@ -56,13 +57,14 @@ def generate(events, backend):
         '};',
         '')
 
-    out('static void trace_register_events(void)',
+    out('static void trace_%(group)s_register_events(void)',
         '{',
-        '    trace_event_register_group(trace_events);',
+        '    trace_event_register_group(%(group)s_trace_events);',
         '}',
-        'trace_init(trace_register_events)')
+        'trace_init(trace_%(group)s_register_events)',
+        group = group.lower())
 
-    backend.generate_begin(active_events)
+    backend.generate_begin(active_events, group)
     for event in active_events:
-        backend.generate(event)
-    backend.generate_end(active_events)
+        backend.generate(event, group)
+    backend.generate_end(active_events, group)

scripts/tracetool/format/d.py

@@ -29,7 +29,7 @@
 )
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     events = [e for e in events
               if "disable" not in e.properties]
 

scripts/tracetool/format/h.py

@@ -16,11 +16,11 @@
 from tracetool import out
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
-        '#ifndef TRACE__GENERATED_TRACERS_H',
-        '#define TRACE__GENERATED_TRACERS_H',
+        '#ifndef TRACE_%s_GENERATED_TRACERS_H' % group.upper(),
+        '#define TRACE_%s_GENERATED_TRACERS_H' % group.upper(),
         '',
         '#include "qemu-common.h"',
         '#include "trace/control.h"',
@@ -46,7 +46,7 @@ def generate(events, backend):
                 enabled=enabled)
         out('#define TRACE_%s_ENABLED %d' % (e.name.upper(), enabled))
 
-    backend.generate_begin(events)
+    backend.generate_begin(events, group)
 
     for e in events:
         if "vcpu" in e.properties:
@@ -68,11 +68,11 @@ def generate(events, backend):
             cond=cond)
 
         if "disable" not in e.properties:
-            backend.generate(e)
+            backend.generate(e, group)
 
         out('    }',
             '}')
 
-    backend.generate_end(events)
+    backend.generate_end(events, group)
 
-    out('#endif /* TRACE__GENERATED_TRACERS_H */')
+    out('#endif /* TRACE_%s_GENERATED_TRACERS_H */' % group.upper())

scripts/tracetool/format/simpletrace_stap.py

@@ -19,7 +19,7 @@
 from tracetool.format.stap import stap_escape
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
         'global event_name_to_id_map',

scripts/tracetool/format/stap.py

@@ -34,7 +34,7 @@ def stap_escape(identifier):
     return identifier
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     events = [e for e in events
               if "disable" not in e.properties]
 

scripts/tracetool/format/tcg_h.py

@@ -27,12 +27,12 @@ def vcpu_transform_args(args):
     ])
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '/* You must include this file after the inclusion of helper.h */',
         '',
-        '#ifndef TRACE__GENERATED_TCG_TRACERS_H',
-        '#define TRACE__GENERATED_TCG_TRACERS_H',
+        '#ifndef TRACE_%s_GENERATED_TCG_TRACERS_H' % group.upper(),
+        '#define TRACE_%s_GENERATED_TCG_TRACERS_H' % group.upper(),
         '',
         '#include "trace.h"',
         '#include "exec/helper-proto.h"',
@@ -63,4 +63,4 @@ def generate(events, backend):
         out('}')
 
     out('',
-        '#endif /* TRACE__GENERATED_TCG_TRACERS_H */')
+        '#endif /* TRACE_%s_GENERATED_TCG_TRACERS_H */' % group.upper())

scripts/tracetool/format/tcg_helper_c.py

@@ -40,7 +40,7 @@ def vcpu_transform_args(args, mode):
             assert False
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     events = [e for e in events
               if "disable" not in e.properties]
 

scripts/tracetool/format/tcg_helper_h.py

@@ -18,7 +18,7 @@
 import tracetool.vcpu
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     events = [e for e in events
               if "disable" not in e.properties]
 

scripts/tracetool/format/tcg_helper_wrapper_h.py

@@ -18,7 +18,7 @@
 import tracetool.vcpu
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     events = [e for e in events
               if "disable" not in e.properties]
 

scripts/tracetool/format/ust_events_c.py

@@ -16,7 +16,7 @@
 from tracetool import out
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     events = [e for e in events
               if "disabled" not in e.properties]
 

scripts/tracetool/format/ust_events_h.py

@@ -16,7 +16,7 @@
 from tracetool import out
 
 
-def generate(events, backend):
+def generate(events, backend, group):
     events = [e for e in events
               if "disabled" not in e.properties]
 
@@ -28,8 +28,9 @@ def generate(events, backend):
         '#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',
+        '#if !defined (TRACE_%s_GENERATED_UST_H) || \\'  % group.upper(),
+        '     defined(TRACEPOINT_HEADER_MULTI_READ)',
+        '#define TRACE_%s_GENERATED_UST_H' % group.upper(),
         '',
         '#include "qemu-common.h"',
         '#include <lttng/tracepoint.h>',
@@ -94,7 +95,7 @@ def generate(events, backend):
                 '',
                 name=e.name)
 
-    out('#endif /* TRACE__GENERATED_UST_H */',
+    out('#endif /* TRACE_%s_GENERATED_UST_H */' % group.upper(),
         '',
         '/* This part must be outside ifdef protection */',
         '#include <lttng/tracepoint-event.h>')