trace: [tcg] Define TCG tracing helper routines

Generates file "trace/generated-helpers.c" with TCG helper definitions to trace
events in guest code at execution time.

The helpers ('helper_trace_${event}_exec_proxy') cast the TCG-compatible native
argument types to their original types (as defined in "trace-events") and call
the tracing routine ('trace_${event}_exec').

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

scripts/tracetool/format/tcg_helper_c.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Generate trace/generated-helpers.c.
+"""
+
+__author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, 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
+from tracetool.transform import *
+
+
+def generate(events, backend):
+    events = [e for e in events
+              if "disable" not in e.properties]
+
+    out('/* This file is autogenerated by tracetool, do not edit. */',
+        '',
+        '#include "qemu-common.h"',
+        '#include "trace.h"',
+        '#include "exec/helper-proto.h"',
+        '',
+        )
+
+    for e in events:
+        if "tcg-exec" not in e.properties:
+            continue
+
+        # tracetool.generate always transforms types to host
+        e_args = e.original.args
+
+        values = ["(%s)%s" % (t, n)
+                  for t, n in e.args.transform(TCG_2_TCG_HELPER_DEF)]
+
+        out('void %(name_tcg)s(%(args)s)',
+            '{',
+            '    %(name)s(%(values)s);',
+            '}',
+            name_tcg="helper_%s_proxy" % e.api(),
+            name=e.api(),
+            args=e_args.transform(HOST_2_TCG_COMPAT, TCG_2_TCG_HELPER_DEF),
+            values=", ".join(values),
+            )