Patchwork [v2] New trace-event backend: stderr

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Submitter Fabien Chouteau
Date Jan. 26, 2011, 11:34 a.m.
Message ID <69207a7f790d1dca508166272a1fe2de4e4ea975.1296040658.git.chouteau@adacore.com>
Download mbox | patch
Permalink /patch/80501/
State New
Headers show

Comments

Fabien Chouteau - Jan. 26, 2011, 11:34 a.m.
This backend sends trace events to standard error output during the emulation.

Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
---
 configure         |    2 +-
 docs/tracing.txt  |    5 +++++
 scripts/tracetool |   53 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 58 insertions(+), 2 deletions(-)
Stefan Hajnoczi - Jan. 26, 2011, 12:34 p.m.
On Wed, Jan 26, 2011 at 11:34 AM, Fabien Chouteau <chouteau@adacore.com> wrote:
> +linetoh_stderr()
> +{
> +    local name args argnamess argc fmt

s/argnamess/argnames/

Stefan
Peter Maydell - Jan. 26, 2011, 12:56 p.m.
On 26 January 2011 11:34, Fabien Chouteau <chouteau@adacore.com> wrote:
> -echo "  --enable-trace-backend=B Trace backend nop simple ust dtrace"
> +echo "  --enable-trace-backend=B Trace backend nop simple stderr ust dtrace"

This is a bit cryptic, especially since there's no punctuation.
Maybe it would be better to have something like the audio
driver options:
echo "  --enable-trace-backend=B Set trace backend:"
echo "                           Available backends: $trace_possible_backends"

(and set trace_possible_backends earlier, perhaps even
automatically by running tracetool?)

-- PMM
Fabien Chouteau - Jan. 26, 2011, 1:05 p.m.
On 01/26/2011 01:34 PM, Stefan Hajnoczi wrote:
> On Wed, Jan 26, 2011 at 11:34 AM, Fabien Chouteau<chouteau@adacore.com>  wrote:
>> +linetoh_stderr()
>> +{
>> +    local name args argnamess argc fmt
>
> s/argnamess/argnames/

Fixed.

Thanks,
Fabien Chouteau - Jan. 26, 2011, 1:23 p.m.
On 01/26/2011 01:56 PM, Peter Maydell wrote:
> On 26 January 2011 11:34, Fabien Chouteau<chouteau@adacore.com>  wrote:
>> -echo "  --enable-trace-backend=B Trace backend nop simple ust dtrace"
>> +echo "  --enable-trace-backend=B Trace backend nop simple stderr ust dtrace"
>
> This is a bit cryptic, especially since there's no punctuation.
> Maybe it would be better to have something like the audio
> driver options:
> echo "  --enable-trace-backend=B Set trace backend:"
> echo "                           Available backends: $trace_possible_backends"
>
> (and set trace_possible_backends earlier, perhaps even
> automatically by running tracetool?)
>
> -- PMM

I will add this in the next version of the patch.

Patch

diff --git a/configure b/configure
index 210670c..560274e 100755
--- a/configure
+++ b/configure
@@ -907,7 +907,7 @@  echo "  --enable-docs            enable documentation build"
 echo "  --disable-docs           disable documentation build"
 echo "  --disable-vhost-net      disable vhost-net acceleration support"
 echo "  --enable-vhost-net       enable vhost-net acceleration support"
-echo "  --enable-trace-backend=B Trace backend nop simple ust dtrace"
+echo "  --enable-trace-backend=B Trace backend nop simple stderr ust dtrace"
 echo "  --with-trace-file=NAME   Full PATH,NAME of file to store traces"
 echo "                           Default:trace-<pid>"
 echo "  --disable-spice          disable spice"
diff --git a/docs/tracing.txt b/docs/tracing.txt
index 963c504..21183f9 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -133,6 +133,11 @@  source tree.  It may not be as powerful as platform-specific or third-party
 trace backends but it is portable.  This is the recommended trace backend
 unless you have specific needs for more advanced backends.
 
+=== Stderr ===
+
+The "stderr" backend sends trace events directly to standard error output
+during emulation.
+
 ==== Monitor commands ====
 
 * info trace
diff --git a/scripts/tracetool b/scripts/tracetool
index fce491c..a686fe2 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -19,6 +19,7 @@  Generate tracing code for a file on stdin.
 Backends:
   --nop     Tracing disabled
   --simple  Simple built-in backend
+  --stderr  Stderr built-in backend
   --ust     LTTng User Space Tracing backend
   --dtrace  DTrace/SystemTAP backend
 
@@ -236,6 +237,56 @@  linetoc_end_simple()
 EOF
 }
 
+#STDERR
+linetoh_begin_stderr()
+{
+    cat <<EOF
+#include <stdio.h>
+EOF
+}
+
+linetoh_stderr()
+{
+    local name args argnamess argc fmt
+    name=$(get_name "$1")
+    args=$(get_args "$1")
+    argnames=$(get_argnames "$1" ",")
+    argc=$(get_argc "$1")
+    fmt=$(get_fmt "$1")
+
+    if [ "$argc" -gt 0 ]; then
+        argnames=", $argnames"
+    fi
+
+    cat <<EOF
+static inline void trace_$name($args)
+{
+    fprintf(stderr, "$name $fmt\n" $argnames);
+}
+EOF
+}
+
+linetoh_end_stderr()
+{
+return
+}
+
+linetoc_begin_stderr()
+{
+return
+}
+
+linetoc_stderr()
+{
+return
+}
+
+linetoc_end_stderr()
+{
+return
+}
+#END OF STDERR
+
 # Clean up after UST headers which pollute the namespace
 ust_clean_namespace() {
     cat <<EOF
@@ -546,7 +597,7 @@  targetarch=
 until [ -z "$1" ]
 do
   case "$1" in
-    "--nop" | "--simple" | "--ust" | "--dtrace") backend="${1#--}" ;;
+    "--nop" | "--simple" | "--stderr" | "--ust" | "--dtrace") backend="${1#--}" ;;
 
     "--binary") shift ; binary="$1" ;;
     "--target-arch") shift ; targetarch="$1" ;;