[Qemu-devel] [PATCH v4 05/10] trace: [tcg] Declare TCG tracing helper routines

[Lluís Vilanova]

Generate header "trace/generated-helpers.h" with the necessary TCG helper
declarations for tracing events in guest code at execution time:

* gen_helper_trace_${event}_exec

  Routine to transform mixed native and TCG argument types to TCG types and call
  TCG helper 'gen_helper_trace_${event}_exec_proxy'.

* helper_trace_${event}_exec_proxy

  TCG helper to cast TCG-compatible argument types to native types and call
  tracing routine 'trace_${event}_exec'.

NOTE: 'gen_gelper_trace_${event}_exec_proxy' is generated by the TCG helper
      machinery.

Signed-off-by: Lluís Vilanova <address@hidden>
---
 .gitignore                               |    1 
 Makefile                                 |    2 +
 scripts/tracetool/__init__.py            |    1 
 scripts/tracetool/format/tcg_helper_h.py |   90 ++++++++++++++++++++++++++++++
 trace/Makefile.objs                      |   24 ++++++--
 5 files changed, 113 insertions(+), 5 deletions(-)
 create mode 100644 scripts/tracetool/format/tcg_helper_h.py

diff --git a/.gitignore b/.gitignore
index c658613..cc6f6c4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@
 /trace/generated-tracers.dtrace
 /trace/generated-events.h
 /trace/generated-events.c
+/trace/generated-helpers.h
 /trace/generated-ust-provider.h
 /trace/generated-ust.c
 /libcacard/trace/generated-tracers.c
diff --git a/Makefile b/Makefile
index 3c8f19c..e3ac3fd 100644
--- a/Makefile
+++ b/Makefile
@@ -57,6 +57,8 @@ GENERATED_HEADERS += trace/generated-tracers-dtrace.h
 endif
 GENERATED_SOURCES += trace/generated-tracers.c
 
+GENERATED_HEADERS += trace/generated-helpers.h
+
 ifeq ($(findstring ust,$(TRACE_BACKENDS)),ust)
 GENERATED_HEADERS += trace/generated-ust-provider.h
 GENERATED_SOURCES += trace/generated-ust.c
diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index de48c80..a51e0f2 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -227,6 +227,7 @@ class Event(object):
                                           fmt)
 
     QEMU_TRACE               = "trace_%(name)s"
+    QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
 
     def api(self, fmt=None):
         if fmt is None:
diff --git a/scripts/tracetool/format/tcg_helper_h.py 
b/scripts/tracetool/format/tcg_helper_h.py
new file mode 100644
index 0000000..ba74483
--- /dev/null
+++ b/scripts/tracetool/format/tcg_helper_h.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Generate trace/generated-helpers.h.
+"""
+
+__author__     = "Lluís Vilanova <address@hidden>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <address@hidden>"
+__license__    = "GPL version 2 or (at your option) any later version"
+
+__maintainer__ = "Stefan Hajnoczi"
+__email__      = "address@hidden"
+
+
+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. */',
+        '',
+        '#define tcg_temp_new_nop(v) (v)',
+        '#define tcg_temp_free_nop(v)',
+        '',
+        )
+
+    for e in events:
+        if "tcg-exec" not in e.properties:
+            continue
+
+        # tracetool.generate always transforms types to host
+        e_args = e.original.args
+
+        # TCG helper proxy declaration
+        fmt = "DEF_HELPER_FLAGS_%(argc)d(%(name)s, %(flags)svoid%(types)s)"
+        args = e_args.transform(HOST_2_TCG_COMPAT, HOST_2_TCG,
+                                TCG_2_TCG_HELPER_DECL)
+        types = ", ".join(args.types())
+        if types != "":
+            types = ", " + types
+
+        flags = "TCG_CALL_NO_RWG, "
+
+        out(fmt,
+            flags=flags,
+            argc=len(args),
+            name=e.api() + "_proxy",
+            types=types,
+            )
+
+        # mixed-type to TCG helper bridge
+        args_tcg_compat = e_args.transform(HOST_2_TCG_COMPAT)
+
+        code_new = [
+            "%(tcg_type)s __%(name)s = %(tcg_func)s(%(name)s);" %
+            {"tcg_type": transform_type(type_, HOST_2_TCG),
+             "tcg_func": transform_type(type_, HOST_2_TCG_TMP_NEW),
+             "name": name}
+            for (type_, name) in args_tcg_compat
+        ]
+
+        code_free = [
+            "%(tcg_func)s(__%(name)s);" %
+            {"tcg_func": transform_type(type_, HOST_2_TCG_TMP_FREE),
+             "name": name}
+            for (type_, name) in args_tcg_compat
+        ]
+
+        gen_name = "gen_helper_" + e.api()
+
+        out(
+            '#ifdef HELPER_GEN_TRACE_PROXY',
+            'static inline void %(name)s(%(args)s)',
+            '{',
+            '    %(code_new)s',
+            '    %(proxy_name)s(%(tmp_names)s);',
+            '    %(code_free)s',
+            '}',
+            '#endif',
+            name=gen_name,
+            args=e_args,
+            proxy_name=gen_name + "_proxy",
+            code_new="\n    ".join(code_new),
+            code_free="\n    ".join(code_free),
+            tmp_names=", ".join(["__%s" % name for _, name in e_args]),
+            )
diff --git a/trace/Makefile.objs b/trace/Makefile.objs
index d7a8696..0a2e6cd 100644
--- a/trace/Makefile.objs
+++ b/trace/Makefile.objs
@@ -49,6 +49,9 @@ util-obj-y += generated-events.o
 ######################################################################
 # Auto-generated tracing routines
 
+##################################################
+# Execution level
+
 $(obj)/generated-tracers.h: $(obj)/generated-tracers.h-timestamp
        @cmp -s $< $@ || cp $< $@
 $(obj)/generated-tracers.h-timestamp: $(SRC_PATH)/trace-events 
$(BUILD_DIR)/config-host.mak
@@ -57,8 +60,8 @@ $(obj)/generated-tracers.h-timestamp: 
$(SRC_PATH)/trace-events $(BUILD_DIR)/conf
                --backends=$(TRACE_BACKENDS) \
                < $< > $@,"  GEN   $(patsubst %-timestamp,%,$@)")
 
-######################################################################
-# Auto-generated tracing routines (non-DTrace)
+##############################
+# non-DTrace
 
 $(obj)/generated-tracers.c: $(obj)/generated-tracers.c-timestamp
        @cmp -s $< $@ || cp $< $@
@@ -70,9 +73,8 @@ $(obj)/generated-tracers.c-timestamp: 
$(SRC_PATH)/trace-events $(BUILD_DIR)/conf
 
 $(obj)/generated-tracers.o: $(obj)/generated-tracers.c 
$(obj)/generated-tracers.h
 
-
-######################################################################
-# Auto-generated DTrace code
+##############################
+# DTrace
 
 # Normal practice is to name DTrace probe file with a '.d' extension
 # but that gets picked up by QEMU's Makefile as an external dependency
@@ -94,6 +96,18 @@ $(obj)/generated-tracers-dtrace.o: 
$(obj)/generated-tracers-dtrace.dtrace
 util-obj-y += generated-tracers-dtrace.o
 endif
 
+##################################################
+# Translation level
+
+$(obj)/generated-helpers.h: $(obj)/generated-helpers.h-timestamp
+$(obj)/generated-helpers.h-timestamp: $(SRC_PATH)/trace-events 
$(BUILD_DIR)/config-host.mak
+       $(call quiet-command,$(TRACETOOL) \
+               --format=tcg-helper-h \
+               --backend=$(TRACE_BACKENDS) \
+               < $< > $@,"  GEN   $(patsubst %-timestamp,%,$@)")
+       @cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst 
%-timestamp,%,$@)
+
+
 ######################################################################
 # Backend code