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>

.gitignore

@@ -12,6 +12,7 @@
 /trace/generated-events.h
 /trace/generated-events.c
 /trace/generated-helpers.h
+/trace/generated-helpers.c
 /trace/generated-ust-provider.h
 /trace/generated-ust.c
 /libcacard/trace/generated-tracers.c

Makefile

@@ -58,6 +58,7 @@ endif
 GENERATED_SOURCES += trace/generated-tracers.c
 
 GENERATED_HEADERS += trace/generated-helpers.h
+GENERATED_SOURCES += trace/generated-helpers.c
 
 ifeq ($(findstring ust,$(TRACE_BACKENDS)),ust)
 GENERATED_HEADERS += trace/generated-ust-provider.h

Makefile.objs

@@ -1,7 +1,7 @@
 #######################################################################
 # Common libraries for tools and emulators
 stub-obj-y = stubs/
-util-obj-y = util/ qobject/ qapi/ trace/
+util-obj-y = util/ qobject/ qapi/
 
 #######################################################################
 # block-obj-y is code used by both qemu system emulation and qemu-img
@@ -106,6 +106,11 @@ common-obj-y += disas/
 version-obj-$(CONFIG_WIN32) += $(BUILD_DIR)/version.o
 version-lobj-$(CONFIG_WIN32) += $(BUILD_DIR)/version.lo
 
+######################################################################
+# tracing
+util-obj-y +=  trace/
+target-obj-y += trace/
+
 ######################################################################
 # guest agent
 

Makefile.target

@@ -159,15 +159,20 @@ endif # CONFIG_SOFTMMU
 dummy := $(call unnest-vars,,obj-y)
 all-obj-y := $(obj-y)
 
+target-obj-y :=
 block-obj-y :=
 common-obj-y :=
 include $(SRC_PATH)/Makefile.objs
+dummy := $(call unnest-vars,,target-obj-y)
+target-obj-y-save := $(target-obj-y)
 dummy := $(call unnest-vars,.., \
                block-obj-y \
                block-obj-m \
                common-obj-y \
                common-obj-m)
+target-obj-y := $(target-obj-y-save)
 all-obj-y += $(common-obj-y)
+all-obj-y += $(target-obj-y)
 all-obj-$(CONFIG_SOFTMMU) += $(block-obj-y)
 
 # build either PROG or PROGW

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),
+            )

trace/Makefile.objs

@@ -107,6 +107,18 @@ $(obj)/generated-helpers.h-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/conf
 		< $< > $@,"  GEN   $(patsubst %-timestamp,%,$@)")
 	@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
 
+$(obj)/generated-helpers.c: $(obj)/generated-helpers.c-timestamp
+$(obj)/generated-helpers.c-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak
+	$(call quiet-command,$(TRACETOOL) \
+		--format=tcg-helper-c \
+		--backend=$(TRACE_BACKENDS) \
+		< $< > $@,"  GEN   $(patsubst %-timestamp,%,$@)")
+	@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
+
+$(obj)/generated-helpers.o: $(obj)/generated-helpers.c
+
+target-obj-y += generated-helpers.o
+
 
 ######################################################################
 # Backend code