Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging

Pull request

Compilation fixes and cleanups for QEMU 4.0.0.

# gpg: Signature made Mon 25 Mar 2019 15:58:28 GMT
# gpg:                using RSA key 9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request:
  trace-events: Fix attribution of trace points to source
  trace-events: Delete unused trace points
  scripts/cleanup-trace-events: Update for current practice
  trace-events: Shorten file names in comments
  trace-events: Consistently point to docs/devel/tracing.txt
  trace: avoid SystemTap dtrace(1) warnings on empty files
  trace: handle tracefs path truncation

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 19 insertions, 5 deletions

diff --git a/scripts/cleanup-trace-events.pl b/scripts/cleanup-trace-events.pl
index e93abc00da..d4f0e4cab5 100755
--- a/scripts/cleanup-trace-events.pl
+++ b/scripts/cleanup-trace-events.pl
@@ -13,6 +13,7 @@
 
 use warnings;
 use strict;
+use File::Basename;
 
 my $buf = '';
 my %seen = ();
@@ -23,12 +24,19 @@ sub out {
     %seen = ();
 }
 
-while (<>) {
-    if (/^(disable )?([a-z_0-9]+)\(/) {
-        open GREP, '-|', 'git', 'grep', '-lw', "trace_$2"
+$#ARGV == 0 or die "usage: $0 FILE";
+my $in = $ARGV[0];
+my $dir = dirname($in);
+open(IN, $in) or die "open $in: $!";
+chdir($dir) or die "chdir $dir: $!";
+
+while (<IN>) {
+    if (/^(disable |(tcg) |vcpu )*([a-z_0-9]+)\(/i) {
+        my $pat = "trace_$3";
+        $pat .= '_tcg' if (defined $2);
+        open GREP, '-|', 'git', 'grep', '-lw', '--max-depth', '1', $pat
             or die "run git grep: $!";
-        my $fname;
-        while ($fname = <GREP>) {
+        while (my $fname = <GREP>) {
             chomp $fname;
             next if $seen{$fname} || $fname eq 'trace-events';
             $seen{$fname} = 1;
@@ -49,3 +57,4 @@ while (<>) {
 }
 
 out;
+close(IN) or die "close $in: $!";
diff --git a/scripts/tracetool/format/d.py b/scripts/tracetool/format/d.py
index 78397c24d2..c7cb2a93a6 100644
--- a/scripts/tracetool/format/d.py
+++ b/scripts/tracetool/format/d.py
@@ -33,6 +33,11 @@ def generate(events, backend, group):
     events = [e for e in events
               if "disable" not in e.properties]
 
+    # SystemTap's dtrace(1) warns about empty "provider qemu {}" but is happy
+    # with an empty file.  Avoid the warning.
+    if not events:
+        return
+
     out('/* This file is autogenerated by tracetool, do not edit. */'
         '',
         'provider qemu {')