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/backend/__init__.py

@@ -113,11 +113,11 @@ class Wrapper:
             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 @@ from tracetool import out
 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 @@ from tracetool import out
 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 @@ from tracetool import out
 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 @@ from tracetool import out
 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