diff options
Diffstat (limited to 'src/tools/check_bison_recursion.pl')
| -rwxr-xr-x | src/tools/check_bison_recursion.pl | 82 |
1 files changed, 49 insertions, 33 deletions
diff --git a/src/tools/check_bison_recursion.pl b/src/tools/check_bison_recursion.pl index f350b26992e..142a7839bd0 100755 --- a/src/tools/check_bison_recursion.pl +++ b/src/tools/check_bison_recursion.pl @@ -32,43 +32,59 @@ my $cur_nonterminal; # We parse the input and emit warnings on the fly. my $in_grammar = 0; -while (<>) { - my $rule_number; - my $rhs; +while (<>) +{ + my $rule_number; + my $rhs; - # We only care about the "Grammar" part of the input. - if (m/^Grammar$/) { - $in_grammar = 1; - } elsif (m/^Terminal/) { - $in_grammar = 0; - } elsif ($in_grammar) { - if (m/^\s*(\d+)\s+(\S+):\s+(.*)$/) { - # first rule for nonterminal - $rule_number = $1; - $cur_nonterminal = $2; - $rhs = $3; - } elsif (m/^\s*(\d+)\s+\|\s+(.*)$/) { - # additional rule for nonterminal - $rule_number = $1; - $rhs = $2; + # We only care about the "Grammar" part of the input. + if (m/^Grammar$/) + { + $in_grammar = 1; } - } + elsif (m/^Terminal/) + { + $in_grammar = 0; + } + elsif ($in_grammar) + { + if (m/^\s*(\d+)\s+(\S+):\s+(.*)$/) + { + + # first rule for nonterminal + $rule_number = $1; + $cur_nonterminal = $2; + $rhs = $3; + } + elsif (m/^\s*(\d+)\s+\|\s+(.*)$/) + { + + # additional rule for nonterminal + $rule_number = $1; + $rhs = $2; + } + } + + # Process rule if we found one + if (defined $rule_number) + { + + # deconstruct the RHS + $rhs =~ s|^/\* empty \*/$||; + my @rhs = split '\s', $rhs; + print "Rule $rule_number: $cur_nonterminal := @rhs\n" if $debug; - # Process rule if we found one - if (defined $rule_number) { - # deconstruct the RHS - $rhs =~ s|^/\* empty \*/$||; - my @rhs = split '\s', $rhs; - print "Rule $rule_number: $cur_nonterminal := @rhs\n" if $debug; - # We complain if the nonterminal appears as the last RHS element - # but not elsewhere, since "expr := expr + expr" is reasonable - my $lastrhs = pop @rhs; - if (defined $lastrhs && - $cur_nonterminal eq $lastrhs && - !grep { $cur_nonterminal eq $_ } @rhs) { - print "Right recursion in rule $rule_number: $cur_nonterminal := $rhs\n"; + # We complain if the nonterminal appears as the last RHS element + # but not elsewhere, since "expr := expr + expr" is reasonable + my $lastrhs = pop @rhs; + if ( defined $lastrhs + && $cur_nonterminal eq $lastrhs + && !grep { $cur_nonterminal eq $_ } @rhs) + { + print +"Right recursion in rule $rule_number: $cur_nonterminal := $rhs\n"; + } } - } } exit 0; |