[Qemu-devel] [PATCH v2 4/4] trace-gen: auto-generate wrappers to call TCG trace helpers

[Lluís]

Auto-generates file "trace-gen.h" with instrumentable wrappers to generate calls
to TCG trace helpers.

Such wrappers are named 'trace_gen_##name', also reachable as
'trace_gen_##name##_backend' when instrumented.

Events with the "gen" property are also able to use TCG types on the trace event
declaration, which are gracefully handled when generating trace functions.

Only trace events with the 'gen' property are affected.

Signed-off-by: Lluís Vilanova <address@hidden>
---
 Makefile     |    8 +++-
 configure    |    5 ++
 trace-events |    3 +
 tracetool    |  131 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 145 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 4effdcc..6737b75 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 # Makefile for QEMU.
 
-GENERATED_HEADERS = config-host.h trace.h trace-helper.h trace-helper.c 
qemu-options.def
+GENERATED_HEADERS = config-host.h trace.h trace-helper.h trace-helper.c 
trace-gen.h qemu-options.def
 
 ifneq ($(wildcard config-host.mak),)
 # Put the all: rule here so that config-host.mak can contain dependencies.
@@ -132,6 +132,11 @@ trace-helper.c-timestamp: $(SRC_PATH)/trace-events 
config-host.mak
 
 trace-helper.o: trace-helper.c $(GENERATED_HEADERS)
 
+trace-gen.h: trace-gen.h-timestamp
+trace-gen.h-timestamp: $(SRC_PATH)/trace-events config-host.mak
+       $(call quiet-command,sh $(SRC_PATH)/tracetool $(TRACETOOL_EXTRA) --gen 
--$(TRACE_BACKEND) -h < $< > $@,"  GEN   trace-gen.h")
+       @cmp -s $@ trace-gen.h || cp $@ trace-gen.h
+
 simpletrace.o: simpletrace.c $(GENERATED_HEADERS)
 
 version.o: $(SRC_PATH)/version.rc config-host.mak
@@ -170,6 +175,7 @@ clean:
        rm -f qemu-img-cmds.h
        rm -f trace.c trace.h trace.c-timestamp trace.h-timestamp
        rm -f trace-helper.c trace-helper.h trace-helper.h-timestamp 
trace-helper.c-timestamp
+       rm -f trace-gen.h-timestamp trace-gen.c-timestamp
        $(MAKE) -C tests clean
        for d in $(ALL_SUBDIRS) libhw32 libhw64 libuser libdis libdis-user; do \
        if test -d $$d; then $(MAKE) -C $$d $@ || exit 1; fi; \
diff --git a/configure b/configure
index 40f94bf..622a9d4 100755
--- a/configure
+++ b/configure
@@ -766,6 +766,11 @@ for opt do
       echo "Error: directory '$instrument' does not contain a 
\"trace-instrument.h\" file"
       echo
       exit 1
+  elif test ! -f "$instrument/trace-gen-instrument.h"; then
+      echo
+      echo "Error: directory '$instrument' does not contain a 
\"trace-gen-instrument.h\" file"
+      echo
+      exit 1
   else
       instrument=`readlink -f $instrument`
   fi
diff --git a/trace-events b/trace-events
index 52e4128..334e19d 100644
--- a/trace-events
+++ b/trace-events
@@ -43,6 +43,9 @@
 #   Provide trace events suitable for using during TCG code generation.
 #   Generates TCG function helpers reachable through 'helper_trace_gen_##name'
 #   which proxy their calls onto 'trace_##name'.
+#   As an extra aid, functions named 'trace_gen_##name' are generated into
+#   "trace-gen.h", which can be reched through 'trace_gen_##name##_backend' 
when
+#   the event is instrumented.
 
 # qemu-malloc.c
 disable qemu_malloc(size_t size, void *ptr) "size %zu ptr %p"
diff --git a/tracetool b/tracetool
index 28d434a..415b318 100755
--- a/tracetool
+++ b/tracetool
@@ -623,6 +623,135 @@ void helper_trace_proxy_$name($args)
 EOF
 }
 
+### Gen - H
+traceto_h_gen()
+{
+     cat <<EOF
+#ifndef TRACE_GEN_H
+#define TRACE_GEN_H
+
+/* This file is autogenerated by tracetool, do not edit. */
+#include "trace.h"
+EOF
+
+    convert h $1 nil
+
+    if [ "$had_instrument" = "1" ]; then
+        echo '#include "trace-gen-instrument.h"'
+    fi
+    echo "#endif /* TRACE_GEN_H */"
+}
+
+line_h_gen_parse_pre()
+{
+    case "$3" in
+        "uint32_t") echo "TCGv_i32 __arg_$1 = tcg_const_i32($2);" ;;
+        "uint64_t") echo "TCGv_i64 __arg_$1 = tcg_const_i64($2);" ;;
+        "void *")   echo "TCGv_ptr __arg_$1 = tcg_const_ptr((int64_t)$2);" ;;
+    esac
+}
+
+line_h_gen_parse_args()
+{
+    case "$3" in
+        "uint64_t") echo "__arg_$1" ;;
+        "uint32_t") echo "__arg_$1" ;;
+        "void *")   echo "__arg_$1" ;;
+        *)          echo "$2"       ;;
+    esac
+}
+
+line_h_gen_parse_post()
+{
+    case "$3" in
+        "uint32_t") echo "tcg_temp_free_i32(__arg_$1);" ;;
+        "uint64_t") echo "tcg_temp_free_i64(__arg_$1);" ;;
+        "void *")   echo "tcg_temp_free_i64(__arg_$1);" ;;
+    esac
+}
+
+line_h_gen()
+{
+    local gen
+    gen=$(get_property "$1" "gen")
+    [ "$gen" = "1" ] || return
+
+    local name args
+    name=$(get_event_name "$1")
+    args=$(get_args "$1")
+
+    local gen_pre gen_post gen_args i
+    gen_pre=""
+    gen_post=""
+    gen_args=""
+
+    local argname
+    i=1
+    for argname in $(get_argnames "$1"); do
+        argname=${argname%,}
+        eval __argname_$i=$argname
+        i=$(($i + 1))
+    done
+
+    local argtypes argtype accum _pre _arg _post
+    argtypes=$(get_argtypes "$1")
+    i=1
+    accum=""
+    for argtype in $argtypes; do
+        accum="$accum ${argtype%,}"
+        if [ "$argtype" = "${argtype%,}" ]; then
+            continue
+        fi
+        argtype="${accum# }"
+        accum=""
+
+        eval argname=\$__argname_$i
+
+        _pre=$(line_h_gen_parse_pre $i $argname "$argtype")
+        gen_pre="$gen_pre
+$_pre"
+        _arg=$(line_h_gen_parse_arg $i $argname "$argtype")
+        gen_args="$gen_args$_arg"
+        _post=$(line_h_gen_parse_post $i $argname "$argtype")
+        gen_post="$gen_post
+$_post"
+
+        i=$(($i + 1))
+    done
+    argtype="${accum# }"
+    eval argname=\$__argname_$i
+
+    _pre=$(line_h_gen_parse_pre $i $argname "$argtype")
+    gen_pre="$gen_pre
+$_pre"
+    _arg=$(line_h_gen_parse_args $i $argname "$argtype")
+    gen_args="$gen_args, $_arg"
+    _post=$(line_h_gen_parse_post $i $argname "$argtype")
+    gen_post="$gen_post
+$_post"
+
+    gen_args="${gen_args#, }"
+
+    cat <<EOF
+static inline void trace_gen_${name}_backend($args)
+{
+$gen_pre
+    gen_helper_trace_proxy_$name($gen_args);
+$gen_post
+}
+EOF
+
+    # XXX: should still provide instrumentation if event is disabled?
+    local instrument
+    instrument=$(get_property "$1" "instrument")
+    if [ "$instrument" = "1" ]; then
+        had_instrument="1"
+        return
+    fi
+
+    echo "#define trace_gen_$name trace_gen_${name}_backend"
+}
+
 
################################################################################
 ### Generic code
 
@@ -684,7 +813,7 @@ EOF
 while [ $# -gt 0 ]; do
     case $1 in
         "--instrument") enable_instrument="1" ;;
-        "--regular"|"--helper") frontend="${1#--}" ;;
+        "--regular"|"--helper"|"--gen") frontend="${1#--}" ;;
         "--nop"|"--simple"|"--ust") backend="${1#--}" ;;
         "-h"|"-c") output="${1#-}" ;;
         "--check-backend") check=1 ;; # used by ./configure to test for backend