kvmtrace_format: read /usr/share/kvm/formats by default

This will help distributions to package kvmtrace and kvmtrace_format, making
kvmtrace_format work out-of-the-box.

The directory is defined at the beginning of the script to make it easier for
distributions to customize the path at install-time, depending on packaging
parameters.

There are no install rules to install kvmtrace and kvmtrace_format, but it
would be interesting to add such rules later. They could replace the PREFIX
definition with the prefix set by ./configure.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/kvm/user/kvmtrace_format b/kvm/user/kvmtrace_format
index 10eb1fe1f..6556475f7 100755
--- a/kvm/user/kvmtrace_format
+++ b/kvm/user/kvmtrace_format
@@ -6,6 +6,11 @@
 
 import re, sys, string, signal, struct, os, getopt, operator
 
+PREFIX = '/usr'
+DATADIR = os.path.join(PREFIX, 'share')
+KVMDIR = os.path.join(DATADIR, 'kvm')
+FORMATS_FILE = os.path.join(KVMDIR, 'formats')
+
 def usage():
     print >> sys.stderr, \
           "Usage: " + sys.argv[0] + """ defs-file
@@ -362,9 +367,6 @@ def get_special(instr):
 
 summary = False
 
-if len(sys.argv) < 2:
-    usage()
-
 try:
     opts, arg = getopt.getopt(sys.argv[1:], "sc:" )
     for opt in opts:
@@ -379,7 +381,10 @@ signal.signal(signal.SIGINT,  sighand)
 
 interrupted = 0
 
-defs = read_defs(arg[0])
+if len(arg) > 0:
+    defs = read_defs(arg[0])
+else:
+    defs = read_defs(FORMATS_FILE)
 
 # structure of trace record (as output by kvmtrace):
 # HDR(I) {TSC(Q)} D1(I) D2(I) D3(I) D4(I) D5(I)