Add stackcollapse-bpftrace.pl

This tool collapses stacks from `bpftrace '{ @stack] = count(); }'`.

Fixes brendangregg#184

stackcollapse-bpftrace.pl

@@ -0,0 +1,66 @@
+#!/usr/bin/perl -w
+#
+# stackcollapse-bpftrace.pl	collapse bpftrace samples into single lines.
+#
+# USAGE ./stackcollapse-bpftrace.pl infile > outfile
+#
+# Example input:
+#
+# @[
+# _raw_spin_lock_bh+0
+# tcp_recvmsg+808
+# inet_recvmsg+81
+# sock_recvmsg+67
+# sock_read_iter+144
+# new_sync_read+228
+# __vfs_read+41
+# vfs_read+142
+# sys_read+85
+# do_syscall_64+115
+# entry_SYSCALL_64_after_hwframe+61
+# ]: 3
+#
+# Example output:
+#
+# entry_SYSCALL_64_after_hwframe+61;do_syscall_64+115;sys_read+85;vfs_read+142;__vfs_read+41;new_sync_read+228;sock_read_iter+144;sock_recvmsg+67;inet_recvmsg+81;tcp_recvmsg+808;_raw_spin_lock_bh+0 3
+#
+# Copyright 2018 Peter Sanford.  All rights reserved.
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+#
+#  (http://www.gnu.org/copyleft/gpl.html)
+#
+
+use strict;
+
+my @stack;
+my $in_stack = 0;
+
+foreach (<>) {
+  chomp;
+  if (!$in_stack) {
+    if (/^@\[/) {
+      $in_stack = 1;
+    }
+  } else {
+    if (m/^\]: (\d+)/) {
+      print join(';', reverse(@stack)) . " $1\n";
+      $in_stack = 0;
+      @stack = ();
+    } else {
+      push(@stack, $_);
+    }
+  }
+}