scripts/reference_discarded.pl

   1 #!/usr/bin/perl -w
   2 #
   3 # reference_discarded.pl (C) Keith Owens 2001 <kaos@ocs.com.au>
   4 #
   5 # Released under GPL V2.
   6 #
   7 # List dangling references to vmlinux discarded sections.
   8
   9 use strict;
  10 die($0 . " takes no arguments\n") if($#ARGV >= 0);
  11
  12 my %object;
  13 my $object;
  14 my $line;
  15 my $ignore;
  16 my $errorcount;
  17
  18 $| = 1;
  19
  20 # printf("Finding objects, ");
  21 open(OBJDUMP_LIST, "find . -name '*.o' | xargs objdump -h |") || die "getting objdump list failed";
  22 while (defined($line = <OBJDUMP_LIST>)) {
  23         chomp($line);
  24         if ($line =~ /:\s+file format/) {
  25                 ($object = $line) =~ s/:.*//;
  26                 $object{$object}->{'module'} = 0;
  27                 $object{$object}->{'size'} = 0;
  28                 $object{$object}->{'off'} = 0;
  29         }
  30         if ($line =~ /^\s*\d+\s+\.modinfo\s+/) {
  31                 $object{$object}->{'module'} = 1;
  32         }
  33         if ($line =~ /^\s*\d+\s+\.comment\s+/) {
  34                 ($object{$object}->{'size'}, $object{$object}->{'off'}) = (split(' ', $line))[2,5];
  35         }
  36 }
  37 close(OBJDUMP_LIST);
  38 # printf("%d objects, ", scalar keys(%object));
  39 $ignore = 0;
  40 foreach $object (keys(%object)) {
  41         if ($object{$object}->{'module'}) {
  42                 ++$ignore;
  43                 delete($object{$object});
  44         }
  45 }
  46 # printf("ignoring %d module(s)\n", $ignore);
  47
  48 # Ignore conglomerate objects, they have been built from multiple objects and we
  49 # only care about the individual objects.  If an object has more than one GCC:
  50 # string in the comment section then it is conglomerate.  This does not filter
  51 # out conglomerates that consist of exactly one object, can't be helped.
  52
  53 # printf("Finding conglomerates, ");
  54 $ignore = 0;
  55 foreach $object (keys(%object)) {
  56         if (exists($object{$object}->{'off'})) {
  57                 my ($off, $size, $comment, $l);
  58                 $off = hex($object{$object}->{'off'});
  59                 $size = hex($object{$object}->{'size'});
  60                 open(OBJECT, "<$object") || die "cannot read $object";
  61                 seek(OBJECT, $off, 0) || die "seek to $off in $object failed";
  62                 $l = read(OBJECT, $comment, $size);
  63                 die "read $size bytes from $object .comment failed" if ($l != $size);
  64                 close(OBJECT);
  65                 if ($comment =~ /GCC\:.*GCC\:/m || $object =~ /built-in\.o/) {
  66                         ++$ignore;
  67                         delete($object{$object});
  68                 }
  69         }
  70 }
  71 # printf("ignoring %d conglomerate(s)\n", $ignore);
  72
  73 # printf("Scanning objects\n");
  74
  75 # Keith Ownes <kaos@sgi.com> commented:
  76 # For our future {in}sanity, add a comment that this is the ppc .opd
  77 # section, not the ia64 .opd section.
  78 # ia64 .opd should not point to discarded sections.
  79 $errorcount = 0;
  80 foreach $object (keys(%object)) {
  81         my $from;
  82         open(OBJDUMP, "objdump -r $object|") || die "cannot objdump -r $object";
  83         while (defined($line = <OBJDUMP>)) {
  84                 chomp($line);
  85                 if ($line =~ /RELOCATION RECORDS FOR /) {
  86                         ($from = $line) =~ s/.*\[([^]]*).*/$1/;
  87                 }
  88                 if (($line =~ /\.text\.exit$/ ||
  89                      $line =~ /\.exit\.text$/ ||
  90                      $line =~ /\.data\.exit$/ ||
  91                      $line =~ /\.exit\.data$/ ||
  92                      $line =~ /\.exitcall\.exit$/) &&
  93                     ($from !~ /\.text\.exit$/ &&
  94                      $from !~ /\.exit\.text$/ &&
  95                      $from !~ /\.data\.exit$/ &&
  96                      $from !~ /\.opd$/ &&
  97                      $from !~ /\.exit\.data$/ &&
  98                      $from !~ /\.altinstructions$/ &&
  99                      $from !~ /\.pdr$/ &&
 100                      $from !~ /\.debug_.*$/ &&
 101                      $from !~ /\.exitcall\.exit$/ &&
 102                      $from !~ /\.eh_frame$/ &&
 103                      $from !~ /\.stab$/)) {
 104                         printf("Error: %s %s refers to %s\n", $object, $from, $line);
 105                         $errorcount = $errorcount + 1;
 106                 }
 107         }
 108         close(OBJDUMP);
 109 }
 110 # printf("Done\n");
 111
 112 exit(0);