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scripts: get_abi.pl: add a graph to speedup the undefined algorithm

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Searching for symlinks is an expensive operation with the current
logic, as it is at the order of O(n^3). In practice, running the
check spends 2-3 minutes to check all symbols.

Fix it by storing the directory tree into a graph, and using
a Breadth First Search (BFS) to find the links for each sysfs node.

With such improvement, it can now report issues with ~11 seconds
on my machine.

It comes with a price, though: there are more symbols reported
as undefined after this change. I suspect it is due to some
sysfs circular loops that are dropped by BFS. Despite such
increase, it seems that the reports are now more coherent.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/f5c1e7b14a27132821c08f0459ba9aea3ed69028.1631957565.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mauro Carvalho Chehab 2021-09-18 11:52:17 +02:00 committed by Greg Kroah-Hartman
parent 0b87a1b81b
commit ca8e055c22
1 changed files with 127 additions and 61 deletions
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188
scripts/get_abi.pl
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@ -546,6 +546,73 @@ sub dont_parse_special_attributes {
my %leaf;
my %aliases;
my @files;
my %root;
sub graph_add_file {
my $file = shift;
my $type = shift;
my $dir = $file;
$dir =~ s,^(.*/).*,$1,;
$file =~ s,.*/,,;
my $name;
my $file_ref = \%root;
foreach my $edge(split "/", $dir) {
$name .= "$edge/";
if (!defined ${$file_ref}{$edge}) {
${$file_ref}{$edge} = { };
}
$file_ref = \%{$$file_ref{$edge}};
${$file_ref}{"__name"} = [ $name ];
}
$name .= "$file";
${$file_ref}{$file} = {
"__name" => [ $name ]
};
return \%{$$file_ref{$file}};
}
sub graph_add_link {
my $file = shift;
my $link = shift;
# Traverse graph to find the reference
my $file_ref = \%root;
foreach my $edge(split "/", $file) {
$file_ref = \%{$$file_ref{$edge}} || die "Missing node!";
}
# do a BFS
my @queue;
my %seen;
my $base_name;
my $st;
push @queue, $file_ref;
$seen{$start}++;
while (@queue) {
my $v = shift @queue;
my @child = keys(%{$v});
foreach my $c(@child) {
next if $seen{$$v{$c}};
next if ($c eq "__name");
# Add new name
my $name = @{$$v{$c}{"__name"}}[0];
if ($name =~ s#^$file/#$link/#) {
push @{$$v{$c}{"__name"}}, $name;
}
# Add child to the queue and mark as seen
push @queue, $$v{$c};
$seen{$c}++;
}
}
}
my $escape_symbols = qr { ([\x01-\x08\x0e-\x1f\x21-\x29\x2b-\x2d\x3a-\x40\x7b-\xfe]) }x;
sub parse_existing_sysfs {
@ -568,19 +635,50 @@ sub parse_existing_sysfs {
return if (defined($data{$file}));
return if (defined($data{$abs_file}));
push @files, $abs_file;
push @files, graph_add_file($abs_file, "file");
}
sub get_leave($)
{
my $what = shift;
my $leave;
my $l = $what;
my $stop = 1;
$leave = $l;
$leave =~ s,/$,,;
$leave =~ s,.*/,,;
$leave =~ s/[\(\)]//g;
# $leave is used to improve search performance at
# check_undefined_symbols, as the algorithm there can seek
# for a small number of "what". It also allows giving a
# hint about a leave with the same name somewhere else.
# However, there are a few occurences where the leave is
# either a wildcard or a number. Just group such cases
# altogether.
if ($leave =~ m/^\.\*/ || $leave eq "" || $leave =~ /^\d+$/) {
$leave = "others";
}
return $leave;
}
sub check_undefined_symbols {
foreach my $file (sort @files) {
foreach my $file_ref (sort @files) {
my @names = @{$$file_ref{"__name"}};
my $file = $names[0];
my $defined = 0;
my $exact = 0;
my $whats = "";
my $found_string;
my $leave = $file;
$leave =~ s,.*/,,;
my $leave = get_leave($file);
if (!defined($leaf{$leave})) {
$leave = "others";
}
my $what = $leaf{$leave};
my $path = $file;
$path =~ s,(.*/).*,$1,;
@ -590,41 +688,12 @@ sub check_undefined_symbols {
$found_string = 1;
}
if ($leave =~ /^\d+$/ || !defined($leaf{$leave})) {
$leave = "others";
}
print "--> $file\n" if ($found_string && $hint);
my $what = $leaf{$leave};
$whats .= " $what" if (!($whats =~ m/$what/));
foreach my $w (split / /, $what) {
if ($file =~ m#^$w$#) {
$exact = 1;
last;
}
}
# Check for aliases
#
# TODO: this algorithm is O(w * n²). It can be
# improved in the future in order to handle it
# faster, by changing parse_existing_sysfs to
# store the sysfs inside a tree, at the expense
# on making the code less readable and/or using some
# additional perl library.
foreach my $a (keys %aliases) {
my $new = $aliases{$a};
my $len = length($new);
if (substr($file, 0, $len) eq $new) {
my $newf = $a . substr($file, $len);
print " $newf\n" if ($found_string && $hint);
foreach my $w (split / /, $what) {
if ($newf =~ m#^$w$#) {
$exact = 1;
last;
}
foreach my $a (@names) {
print "--> $a\n" if ($found_string && $hint);
foreach my $w (split /\xac/, $what) {
if ($a =~ m#^$w$#) {
$exact = 1;
last;
}
}
}
@ -641,8 +710,13 @@ sub check_undefined_symbols {
# is not easily parseable.
next if ($file =~ m#/parameters/#);
if ($hint && $defined && $leave ne "others") {
print "$leave at $path might be one of:$whats\n" if (!$search_string || $found_string);
if ($hint && $defined && (!$search_string || $found_string)) {
$what =~ s/\xac/\n\t/g;
if ($leave ne "others") {
print " more likely regexes:\n\t$what\n";
} else {
print " tested regexes:\n\t$what\n";
}
next;
}
print "$file not found.\n" if (!$search_string || $found_string);
@ -656,8 +730,10 @@ sub undefined_symbols {
no_chdir => 1
}, $sysfs_prefix);
$leaf{"others"} = "";
foreach my $w (sort keys %data) {
foreach my $what (split /\xac /,$w) {
foreach my $what (split /\xac/,$w) {
next if (!($what =~ m/^$sysfs_prefix/));
# Convert what into regular expressions
@ -700,19 +776,7 @@ sub undefined_symbols {
# (this happens on a few IIO definitions)
$what =~ s,\s*\=.*$,,;
my $leave = $what;
$leave =~ s,.*/,,;
# $leave is used to improve search performance at
# check_undefined_symbols, as the algorithm there can seek
# for a small number of "what". It also allows giving a
# hint about a leave with the same name somewhere else.
# However, there are a few occurences where the leave is
# either a wildcard or a number. Just group such cases
# altogether.
if ($leave =~ m/^\.\*/ || $leave eq "" || $leave =~ /^\d+$/) {
$leave = "others" ;
}
my $leave = get_leave($what);
# Escape all other symbols
$what =~ s/$escape_symbols/\\$1/g;
@ -722,17 +786,14 @@ sub undefined_symbols {
$what =~ s/\xff/\\d+/g;
# Special case: IIO ABI which a parenthesis.
$what =~ s/sqrt(.*)/sqrt\(.*\)/;
$leave =~ s/[\(\)]//g;
my $added = 0;
foreach my $l (split /\|/, $leave) {
if (defined($leaf{$l})) {
next if ($leaf{$l} =~ m/$what/);
$leaf{$l} .= " " . $what;
next if ($leaf{$l} =~ m/\b$what\b/);
$leaf{$l} .= "\xac" . $what;
$added = 1;
} else {
$leaf{$l} = $what;
@ -745,6 +806,11 @@ sub undefined_symbols {
}
}
# Take links into account
foreach my $link (keys %aliases) {
my $abs_file = $aliases{$link};
graph_add_link($abs_file, $link);
}
check_undefined_symbols;
}