diff --git a/t/chainlint.pl b/t/chainlint.pl index 81ffbf28bf..cdf136896b 100755 --- a/t/chainlint.pl +++ b/t/chainlint.pl @@ -198,6 +198,249 @@ RESTART: return length($token) ? $token : undef; } +# ShellParser parses POSIX shell scripts (with minor extensions for Bash). It +# is a recursive descent parser very roughly modeled after section 2.10 "Shell +# Grammar" of POSIX chapter 2 "Shell Command Language". +package ShellParser; + +sub new { + my ($class, $s) = @_; + my $self = bless { + buff => [], + stop => [], + output => [] + } => $class; + $self->{lexer} = Lexer->new($self, $s); + return $self; +} + +sub next_token { + my $self = shift @_; + return pop(@{$self->{buff}}) if @{$self->{buff}}; + return $self->{lexer}->scan_token(); +} + +sub untoken { + my $self = shift @_; + push(@{$self->{buff}}, @_); +} + +sub peek { + my $self = shift @_; + my $token = $self->next_token(); + return undef unless defined($token); + $self->untoken($token); + return $token; +} + +sub stop_at { + my ($self, $token) = @_; + return 1 unless defined($token); + my $stop = ${$self->{stop}}[-1] if @{$self->{stop}}; + return defined($stop) && $token =~ $stop; +} + +sub expect { + my ($self, $expect) = @_; + my $token = $self->next_token(); + return $token if defined($token) && $token eq $expect; + push(@{$self->{output}}, "?!ERR?! expected '$expect' but found '" . (defined($token) ? $token : "") . "'\n"); + $self->untoken($token) if defined($token); + return (); +} + +sub optional_newlines { + my $self = shift @_; + my @tokens; + while (my $token = $self->peek()) { + last unless $token eq "\n"; + push(@tokens, $self->next_token()); + } + return @tokens; +} + +sub parse_group { + my $self = shift @_; + return ($self->parse(qr/^}$/), + $self->expect('}')); +} + +sub parse_subshell { + my $self = shift @_; + return ($self->parse(qr/^\)$/), + $self->expect(')')); +} + +sub parse_case_pattern { + my $self = shift @_; + my @tokens; + while (defined(my $token = $self->next_token())) { + push(@tokens, $token); + last if $token eq ')'; + } + return @tokens; +} + +sub parse_case { + my $self = shift @_; + my @tokens; + push(@tokens, + $self->next_token(), # subject + $self->optional_newlines(), + $self->expect('in'), + $self->optional_newlines()); + while (1) { + my $token = $self->peek(); + last unless defined($token) && $token ne 'esac'; + push(@tokens, + $self->parse_case_pattern(), + $self->optional_newlines(), + $self->parse(qr/^(?:;;|esac)$/)); # item body + $token = $self->peek(); + last unless defined($token) && $token ne 'esac'; + push(@tokens, + $self->expect(';;'), + $self->optional_newlines()); + } + push(@tokens, $self->expect('esac')); + return @tokens; +} + +sub parse_for { + my $self = shift @_; + my @tokens; + push(@tokens, + $self->next_token(), # variable + $self->optional_newlines()); + my $token = $self->peek(); + if (defined($token) && $token eq 'in') { + push(@tokens, + $self->expect('in'), + $self->optional_newlines()); + } + push(@tokens, + $self->parse(qr/^do$/), # items + $self->expect('do'), + $self->optional_newlines(), + $self->parse_loop_body(), + $self->expect('done')); + return @tokens; +} + +sub parse_if { + my $self = shift @_; + my @tokens; + while (1) { + push(@tokens, + $self->parse(qr/^then$/), # if/elif condition + $self->expect('then'), + $self->optional_newlines(), + $self->parse(qr/^(?:elif|else|fi)$/)); # if/elif body + my $token = $self->peek(); + last unless defined($token) && $token eq 'elif'; + push(@tokens, $self->expect('elif')); + } + my $token = $self->peek(); + if (defined($token) && $token eq 'else') { + push(@tokens, + $self->expect('else'), + $self->optional_newlines(), + $self->parse(qr/^fi$/)); # else body + } + push(@tokens, $self->expect('fi')); + return @tokens; +} + +sub parse_loop_body { + my $self = shift @_; + return $self->parse(qr/^done$/); +} + +sub parse_loop { + my $self = shift @_; + return ($self->parse(qr/^do$/), # condition + $self->expect('do'), + $self->optional_newlines(), + $self->parse_loop_body(), + $self->expect('done')); +} + +sub parse_func { + my $self = shift @_; + return ($self->expect('('), + $self->expect(')'), + $self->optional_newlines(), + $self->parse_cmd()); # body +} + +sub parse_bash_array_assignment { + my $self = shift @_; + my @tokens = $self->expect('('); + while (defined(my $token = $self->next_token())) { + push(@tokens, $token); + last if $token eq ')'; + } + return @tokens; +} + +my %compound = ( + '{' => \&parse_group, + '(' => \&parse_subshell, + 'case' => \&parse_case, + 'for' => \&parse_for, + 'if' => \&parse_if, + 'until' => \&parse_loop, + 'while' => \&parse_loop); + +sub parse_cmd { + my $self = shift @_; + my $cmd = $self->next_token(); + return () unless defined($cmd); + return $cmd if $cmd eq "\n"; + + my $token; + my @tokens = $cmd; + if ($cmd eq '!') { + push(@tokens, $self->parse_cmd()); + return @tokens; + } elsif (my $f = $compound{$cmd}) { + push(@tokens, $self->$f()); + } elsif (defined($token = $self->peek()) && $token eq '(') { + if ($cmd !~ /\w=$/) { + push(@tokens, $self->parse_func()); + return @tokens; + } + $tokens[-1] .= join(' ', $self->parse_bash_array_assignment()); + } + + while (defined(my $token = $self->next_token())) { + $self->untoken($token), last if $self->stop_at($token); + push(@tokens, $token); + last if $token =~ /^(?:[;&\n|]|&&|\|\|)$/; + } + push(@tokens, $self->next_token()) if $tokens[-1] ne "\n" && defined($token = $self->peek()) && $token eq "\n"; + return @tokens; +} + +sub accumulate { + my ($self, $tokens, $cmd) = @_; + push(@$tokens, @$cmd); +} + +sub parse { + my ($self, $stop) = @_; + push(@{$self->{stop}}, $stop); + goto DONE if $self->stop_at($self->peek()); + my @tokens; + while (my @cmd = $self->parse_cmd()) { + $self->accumulate(\@tokens, \@cmd); + last if $self->stop_at($self->peek()); + } +DONE: + pop(@{$self->{stop}}); + return @tokens; +} + package ScriptParser; sub new {