trace: [tracetool] Minimize the amount of per-backend code

Backends now only contain the essential backend-specific code, and most of the work is moved to frontend code.

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

scripts/tracetool/backend/dtrace.py

@@ -21,7 +21,7 @@ PUBLIC = True
 
 PROBEPREFIX = None
 
-def _probeprefix():
+def probeprefix():
     if PROBEPREFIX is None:
         raise ValueError("you must set PROBEPREFIX")
     return PROBEPREFIX
@@ -29,81 +29,18 @@ def _probeprefix():
 
 BINARY = None
 
-def _binary():
+def binary():
     if BINARY is None:
         raise ValueError("you must set BINARY")
     return BINARY
 
 
-def c(events):
-    pass
-
-
-def h(events):
+def generate_h_begin(events):
     out('#include "trace/generated-tracers-dtrace.h"',
         '')
 
-    for e in events:
-        out('static inline void %(api)s(%(args)s) {',
-            '    QEMU_%(uppername)s(%(argnames)s);',
-            '}',
-            api = e.api(),
-            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('',
-        '};')
-
-
-# Technically 'self' is not used by systemtap yet, but
-# they recommended we keep it in the reserved list anyway
-RESERVED_WORDS = (
-    'break', 'catch', 'continue', 'delete', 'else', 'for',
-    'foreach', 'function', 'global', 'if', 'in', 'limit',
-    'long', 'next', 'probe', 'return', 'self', 'string',
-    'try', 'while'
-    )
-
-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():
-                # Append underscore to reserved keywords
-                if name in RESERVED_WORDS:
-                    name += '_'
-                out('  %s = $arg%d;' % (name, i))
-                i += 1
-
-        out('}')
-
-    out()
+def generate_h(event):
+    out('    QEMU_%(uppername)s(%(argnames)s);',
+        uppername=event.name.upper(),
+        argnames=", ".join(event.args.names()))