src: rewrite systemtap probe generator in Python

As part of a goal to eliminate Perl from libvirt build tools,
rewrite the dtrace2systemtap.pl tool in Python.

This was a straight conversion, manually going line-by-line to
change the syntax from Perl to Python. Thus the overall structure
of the file and approach is the same.

The "--with-modules" flag was dropped because this functionality
is not implicitly always enabled.

Tested-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This commit is contained in:
Daniel P. Berrangé 2019-08-30 13:22:54 +01:00
parent d30a1ad044
commit 952c018efe
4 changed files with 147 additions and 137 deletions

View File

@ -50,6 +50,7 @@ EXTRA_DIST = \
scripts/check-aclperms.py \
scripts/check-symfile.py \
scripts/check-symsorting.py \
scripts/dtrace2systemtap.py \
scripts/header-ifdef.py \
scripts/minimize-po.py \
scripts/mock-noinline.py \

143
scripts/dtrace2systemtap.py Executable file
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@ -0,0 +1,143 @@
#!/usr/bin/env python
#
# Copyright (C) 2011-2019 Red Hat, Inc.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library. If not, see
# <http://www.gnu.org/licenses/>.
#
#
# Generate a set of systemtap probe definitions corresponding to
# DTrace probe markers in libvirt.so
#
# python dtrace2systemtap.py probes.d > libvirt_probes.stp
#
from __future__ import print_function
import re
import sys
file = None
filelist = []
files = {}
bindir = sys.argv[1]
sbindir = sys.argv[2]
libdir = sys.argv[3]
dtrace = sys.argv[4]
probe = None
args = None
# Read the DTraceprobes definition
with open(dtrace, "r") as fh:
lineno = 0
for line in fh:
lineno = lineno + 1
line = line.strip()
if line == "":
continue
if line.find("provider ") != -1 and line.find("{") != -1:
continue
if line.find("};") != -1:
continue
if line.startswith("#"):
m = re.search(r'''^\#\s*file:\s*(\S+)$''', line)
if m is not None:
file = m.group(1)
filelist.append(file)
files[file] = {"prefix": None, "probes": []}
continue
m = re.search(r'''^\#\s*prefix:\s*(\S+)$''', line)
if m is not None:
files[file]["prefix"] = m.group(1)
continue
m = re.search(r'''^\#\s*binary:\s*(\S+)$''', line)
if m is not None:
files[file]["binary"] = m.group(1)
continue
m = re.search(r'''^\#\s*module:\s*(\S+)$''', line)
if m is not None:
files[file]["module"] = m.group(1)
# ignore unknown comments
else:
m = re.search(r'''probe\s+([a-zA-Z0-9_]+)\((.*?)(\);)?$''', line)
if m is not None:
probe = m.group(1)
args = m.group(2)
if m.group(3) is not None:
files[file]["probes"].append([probe, args])
probe = None
args = None
elif probe is not None:
m = re.search(r'''^(.*?)(\);)?$''', line)
if m is not None:
args = args + m.group(1)
if m.group(2) is not None:
files[file]["probes"].append([probe, args])
probe = None
args = None
else:
raise Exception("unexpected data %s on line %d" %
(line, lineno))
else:
raise Exception("unexpected data %s on line %d" %
(line, lineno))
# Write out the SystemTap probes
for file in filelist:
prefix = files[file]["prefix"]
probes = files[file]["probes"]
print("# %s\n" % file)
for probe in probes:
name = probe[0]
args = probe[1]
pname = name.replace(prefix + "_", "libvirt." + prefix + ".")
binary = libdir + "/libvirt.so"
if "binary" in files[file]:
binary = sbindir + "/" + files[file]["binary"]
if "module" in files[file]:
binary = libdir + "/" + files[file]["module"]
print("probe %s = process(\"%s\").mark(\"%s\") {" %
(pname, binary, name))
argbits = args.split(",")
for idx in range(len(argbits)):
arg = argbits[idx]
isstr = False
if arg.find("char *") != -1:
isstr = True
m = re.search(r'''^.*\s\*?(\S+)$''', arg)
if m is not None:
arg = m.group(1)
else:
raise Exception("Malformed arg %s" % arg)
if isstr:
print(" %s = user_string($arg%d);" % (arg, idx + 1))
else:
print(" %s = $arg%d;" % (arg, idx + 1))
print("}\n")
print("")

View File

@ -527,7 +527,6 @@ if WITH_DTRACE_PROBES
libvirt_la_BUILT_LIBADD += libvirt_probes.lo
libvirt_la_DEPENDENCIES += libvirt_probes.lo libvirt_probes.o
nodist_libvirt_la_SOURCES = libvirt_probes.h
DTRACE2SYSTEMTAP_FLAGS = --with-modules
BUILT_SOURCES += libvirt_probes.h libvirt_probes.stp libvirt_functions.stp
@ -562,10 +561,10 @@ RPC_PROBE_FILES += $(srcdir)/rpc/virnetprotocol.x \
libvirt_functions.stp: $(RPC_PROBE_FILES) $(srcdir)/rpc/gensystemtap.pl
$(AM_V_GEN)$(PERL) -w $(srcdir)/rpc/gensystemtap.pl $(RPC_PROBE_FILES) > $@
%_probes.stp: %_probes.d $(srcdir)/dtrace2systemtap.pl \
%_probes.stp: %_probes.d $(top_srcdir)/scripts/dtrace2systemtap.py \
$(top_builddir)/config.status
$(AM_V_GEN)$(PERL) -w $(srcdir)/dtrace2systemtap.pl \
$(DTRACE2SYSTEMTAP_FLAGS) $(bindir) $(sbindir) $(libdir) $< > $@
$(AM_V_GEN)$(RUNUTF8) $(PYTHON) $(top_srcdir)/scripts/dtrace2systemtap.py \
$(bindir) $(sbindir) $(libdir) $< > $@
CLEANFILES += libvirt_probes.h libvirt_probes.o libvirt_probes.lo \
libvirt_functions.stp libvirt_probes.stp
@ -686,9 +685,6 @@ endif LIBVIRT_INIT_SCRIPT_SYSTEMD
endif WITH_LIBVIRTD
EXTRA_DIST += dtrace2systemtap.pl
if WITH_LIBVIRTD
libexec_PROGRAMS += libvirt_iohelper
libvirt_iohelper_SOURCES = $(UTIL_IO_HELPER_SOURCES)

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@ -1,130 +0,0 @@
#!/usr/bin/env perl
#
# Copyright (C) 2011-2012 Red Hat, Inc.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library. If not, see
# <http://www.gnu.org/licenses/>.
#
#
# Generate a set of systemtap probe definitions corresponding to
# DTrace probe markers in libvirt.so
#
# perl dtrace2systemtap.pl probes.d > libvirt_probes.stp
#
use strict;
use warnings;
my $file;
my @files;
my %files;
my $with_modules = 0;
if ($ARGV[0] eq "--with-modules") {
# set if we want to honor the "module" setting in the .d file
$with_modules = 1;
shift @ARGV;
}
my $bindir = shift @ARGV;
my $sbindir = shift @ARGV;
my $libdir = shift @ARGV;
my $probe;
my $args;
# Read the DTraceprobes definition
while (<>) {
next if m,^\s*$,;
next if /^\s*provider\s+\w+\s*{\s*$/;
next if /^\s*};\s*$/;
if (m,^\s*\#,) {
if (m,^\s*\#\s*file:\s*(\S+)\s*$,) {
$file = $1;
push @files, $file;
$files{$file} = { prefix => undef, probes => [] };
} elsif (m,^\s*\#\s*prefix:\s*(\S+)\s*$,) {
$files{$file}->{prefix} = $1;
} elsif (m,^\s*\#\s*binary:\s*(\S+)\s*$,) {
$files{$file}->{binary} = $1;
} elsif (m,^\s*\#\s*module:\s*(\S+)\s*$,) {
$files{$file}->{module} = $1;
} else {
# ignore unknown comments
}
} else {
if (m,\s*probe\s+([a-zA-Z0-9_]+)\((.*?)(\);)?$,) {
$probe = $1;
$args = $2;
if ($3) {
push @{$files{$file}->{probes}}, [$probe, $args];
$probe = $args = undef;
}
} elsif ($probe) {
if (m,^(.*?)(\);)?$,) {
$args .= $1;
if ($2) {
push @{$files{$file}->{probes}}, [$probe, $args];
$probe = $args = undef;
}
} else {
die "unexpected data $_ on line $.";
}
} else {
die "unexpected data $_ on line $.";
}
}
}
# Write out the SystemTap probes
foreach my $file (@files) {
my $prefix = $files{$file}->{prefix};
my @probes = @{$files{$file}->{probes}};
print "# $file\n\n";
foreach my $probe (@probes) {
my $name = $probe->[0];
my $args = $probe->[1];
my $pname = $name;
$pname =~ s/${prefix}_/libvirt.$prefix./;
my $binary = "$libdir/libvirt.so";
if (exists $files{$file}->{binary}) {
$binary = $sbindir . "/" . $files{$file}->{binary};
}
if ($with_modules && exists $files{$file}->{module}) {
$binary = $libdir . "/" . $files{$file}->{module};
}
print "probe $pname = process(\"$binary\").mark(\"$name\") {\n";
my @args = split /,/, $args;
for (my $i = 0 ; $i <= $#args ; $i++) {
my $arg = $args[$i];
my $isstr = $arg =~ /char\s+\*/;
$arg =~ s/^.*\s\*?(\S+)$/$1/;
if ($isstr) {
print " $arg = user_string(\$arg", $i + 1, ");\n";
} else {
print " $arg = \$arg", $i + 1, ";\n";
}
}
print "}\n\n";
}
print "\n";
}