modules/Parser.pm

   1 package Parser;
   2
   3 # ************************************************************
   4 # Description   : A basic parser that requires a parse_line override
   5 # Author        : Chad Elliott
   6 # Create Date   : 5/16/2002
   7 # ************************************************************
   8
   9 # ************************************************************
  10 # Pragmas
  11 # ************************************************************
  12
  13 use strict;
  14 use FileHandle;
  15
  16 use mpc_debug;
  17 use OutputMessage;
  18 use StringProcessor;
  19 use DirectoryManager;
  20
  21 use vars qw(@ISA);
  22 @ISA = qw(OutputMessage StringProcessor DirectoryManager);
  23
  24 # ************************************************************
  25 # Data Section
  26 # ************************************************************
  27
  28 my %filecache;
  29
  30 # ************************************************************
  31 # Subroutine Section
  32 # ************************************************************
  33
  34 sub new {
  35   my($class, $inc) = @_;
  36   my $self = $class->SUPER::new();
  37
  38   ## Set up the internal data members.
  39   $self->{'line_number'} = 0;
  40   $self->{'include'}     = $inc;
  41
  42   return $self;
  43 }
  44
  45
  46 sub strip_comments {
  47   my($self, $line) = @_;
  48
  49   $line =~ s/\/\/.*//;
  50   return $line;
  51 }
  52
  53
  54 sub strip_lt_whitespace {
  55   my($self, $line, $keep_leading_whitespace) = @_;
  56
  57   $line =~ s/^\s+// if !$keep_leading_whitespace;
  58   $line =~ s/\s+$//;
  59   return $line;
  60 }
  61
  62
  63 sub is_blank_line {
  64   my($self, $line) = @_;
  65   return m/^\s+$/;
  66 }
  67
  68
  69 sub strip_line {
  70   my($self, $line) = @_;
  71
  72   ## Keep track of our line number
  73   ++$self->{'line_number'};
  74
  75   $line = $self->strip_comments($line);
  76   $line = $self->strip_lt_whitespace($line);
  77
  78   return $line;
  79 }
  80
  81
  82 sub preprocess_line {
  83   #my $self = shift;
  84   #my $fh   = shift;
  85   #my $line = shift;
  86   return $_[0]->strip_line($_[2]);
  87 }
  88
  89
  90 sub read_file {
  91   my($self, $input, $cache) = @_;
  92   my $ih = new FileHandle();
  93   my $status = 1;
  94   my $errorString;
  95
  96   mpc_debug::chkpnt_pre_read_file($input, $cache);
  97   $self->{'line_number'} = 0;
  98   if (open($ih, $input)) {
  99     $self->debug("Open $input");
 100     if ($cache) {
 101       ## If we don't have an array for this file, then start one
 102       $filecache{$input} = [] if (!defined $filecache{$input});
 103
 104       while(<$ih>) {
 105         ## Preprocess the line
 106         my $line = $self->preprocess_line($ih, $_);
 107
 108         ## Push the line onto the array for this file
 109         push(@{$filecache{$input}}, $line);
 110
 111         ## Parse the line
 112         ($status, $errorString) = $self->parse_line($ih, $line);
 113
 114         ## Stop reading the file if we've encountered an error
 115         last if (!$status);
 116       }
 117     }
 118     else {
 119       ## We're not caching, so we just preprocess and parse in one call.
 120       while(<$ih>) {
 121         ($status, $errorString) = $self->parse_line(
 122                                     $ih, $self->preprocess_line($ih, $_));
 123
 124         ## Stop reading the file if we've encountered an error
 125         last if (!$status);
 126       }
 127     }
 128     $self->debug("Close $input");
 129     close($ih);
 130   }
 131   else {
 132     $errorString = "Unable to open \"$input\" for reading";
 133     $status = 0;
 134   }
 135   mpc_debug::chkpnt_post_read_file($input, $cache, $status, $errorString);
 136
 137   return $status, $errorString;
 138 }
 139
 140
 141 sub cached_file_read {
 142   my($self, $input) = @_;
 143   my $lines = $filecache{$input};
 144
 145   if (defined $lines) {
 146     my $status = 1;
 147     my $error;
 148     $self->{'line_number'} = 0;
 149     foreach my $line (@$lines) {
 150       ++$self->{'line_number'};
 151
 152       ## Since we're "reading" a cached file, we must pass undef as the
 153       ## file handle to parse_line().
 154       ($status, $error) = $self->parse_line(undef, $line);
 155
 156       ## Stop "reading" the file if we've encountered an error
 157       last if (!$status);
 158     }
 159     return $status, $error;
 160   }
 161
 162   ## We haven't cached this file yet, read it and cache it.
 163   return $self->read_file($input, 1);
 164 }
 165
 166
 167 sub get_line_number {
 168   return $_[0]->{'line_number'};
 169 }
 170
 171
 172 sub set_line_number {
 173   my($self, $number) = @_;
 174   $self->{'line_number'} = $number;
 175 }
 176
 177
 178 sub slash_to_backslash {
 179   ## This method is here solely for convenience.  It's used to make the
 180   ## calling code look cleaner.
 181   my($self, $file) = @_;
 182   $file =~ s/\//\\/g;
 183   return $file;
 184 }
 185
 186
 187 sub get_include_path {
 188   return $_[0]->{'include'};
 189 }
 190
 191
 192 sub search_include_path {
 193   my($self, $file) = @_;
 194
 195   foreach my $include ('.', @{$self->{'include'}}) {
 196     return "$include/$file" if (-r "$include/$file");
 197   }
 198
 199   return undef;
 200 }
 201
 202
 203 sub escape_regex_special {
 204   my($self, $name) = @_;
 205   $name =~ s/([\+\-\\\$\[\]\(\)\.])/\\$1/g;
 206   return $name;
 207 }
 208
 209
 210 # ************************************************************
 211 # Virtual Methods To Be Overridden
 212 # ************************************************************
 213
 214 sub parse_line {
 215   #my $self = shift;
 216   #my $ih   = shift;
 217   #my $line = shift;
 218 }
 219
 220
 221 1;