X-Git-Url: http://git.etherboot.org/people/indolent/gpxe.git/.git/blobdiff_plain/d94cb571434ab1339a7906893826f744327cb826..c3290aae5406e334830009cf5ce8d64d551e0f58:/src/util/symcheck.pl

diff --git a/src/util/symcheck.pl b/src/util/symcheck.pl
index 5fb3c954..6e46ae46 100755
--- a/src/util/symcheck.pl
+++ b/src/util/symcheck.pl
@@ -3,47 +3,141 @@
 use strict;
 use warnings;
 
-my $symbols = {};
+use constant WARNING_SIZE => 512;
 
-# Scan output of "nm -o -g bin/blib.a" and build up symbol cross-ref table
+my $symtab = {};
+
+# Scan output of "objdump -w -t bin/blib.a" and build up symbol table
 #
+my $object;
 while ( <> ) {
   chomp;
-  ( my $object, my $type, my $symbol ) = /^.*?:(.*?\.o):.*?\s(\S)\s(.*)$/;
-  my $category = $type eq 'U' ? "requires" : "provides";
-  $symbols->{$symbol}->{$category}->{$object} = 1;
+  if ( /^In archive/ ) {
+    # Do nothing
+  } elsif ( /^$/ ) {
+    # Do nothing
+  } elsif ( /^(\S+\.o):\s+file format/ ) {
+    $object = $1;
+  } elsif ( /^SYMBOL TABLE:/ ) {
+    # Do nothing
+  } elsif ( /^([0-9a-fA-F]+)\s(l|g|\s)......\s(\S+)\s+([0-9a-fA-F]+)\s+(\S+)$/ ) {
+    my $value = $1;
+    my $scope = $2;
+    my $section = $3;
+    my $size = $4;
+    my $symbol = $5;
+    $symtab->{$object}->{$symbol} = {
+      global	=> ( $scope ne "l" ),
+      section	=> ( $section eq "*UND*" ? undef : $section ),
+      value	=> ( $value ? hex ( $value ) : 0 ),
+      size	=> ( $size ? hex ( $size ) : 0 ),
+    };
+  } else {
+    die "Unrecognized line \"$_\"";
+  }
 }
 
 # Add symbols that we know will be generated or required by the linker
 #
-while ( ( my $symbol, my $info ) = each %$symbols ) {
-  $info->{requires}->{LINKER} = 1 if $symbol =~ /^obj_/;
+foreach my $object ( keys %$symtab ) {
+  my $obj_symbol = "obj_$object";
+  $obj_symbol =~ s/\.o$//;
+  $obj_symbol =~ s/\W/_/g;
+  $symtab->{LINKER}->{$obj_symbol} = {
+    global	=> 1,
+    section	=> undef,
+    value	=> 0,
+    size	=> 0,
+  };
+}
+foreach my $link_sym qw ( __prefix _prefix _prefix_load_offset
+			  _prefix_size _prefix_progbits_size _prefix_size_pgh
+			  __text16 _text16 _text16_load_offset
+			  _text16_size _text16_progbits_size _text16_size_pgh
+			  __data16 _data16 _data16_load_offset
+			  _data16_size _data16_progbits_size _data16_size_pgh
+			  __text _text __data _data _textdata_load_offset
+			  _textdata_size _textdata_progbits_size
+			  __rodata __bss _end
+			  _payload_offset _max_align
+			  _load_size _load_size_pgh _load_size_sect
+			  pci_vendor_id pci_device_id ) {
+  $symtab->{LINKER}->{$link_sym} = {
+    global	=> 1,
+    section	=> '*ABS*',
+    value	=> 0,
+    size	=> 0,
+  };
+}
+
+# Build up requires, provides and shares symbol tables for global
+# symbols
+#
+my $globals = {};
+while ( ( my $object, my $symbols ) = each %$symtab ) {
+  while ( ( my $symbol, my $info ) = each %$symbols ) {
+    if ( $info->{global} ) {
+      my $category;
+      if ( ! defined $info->{section} ) {
+	$category = "requires";
+      } elsif ( $info->{section} eq "*COM*" ) {
+	$category = "shares";
+      } else {
+	$category = "provides";
+      }
+      $globals->{$symbol}->{$category}->{$object} = $info->{section};
+    }
+  }
 }
-$symbols->{$_}->{provides}->{LINKER} = 1
-    foreach qw ( _prefix _eprefix _decompress _edecompress _text
-		 _etext _data _edata _bss _ebss _end device_drivers
-		 device_drivers_end bus_drivers bus_drivers_end
-		 type_drivers type_drivers_end console_drivers
-		 console_drivers_end post_reloc_fns post_reloc_fns_end
-		 init_fns init_fns_end );
 
-# Check for multiply defined, never-defined and unused symbols
+# Check for multiply defined, never-defined and unused global symbols
 #
 my $problems = {};
-while ( ( my $symbol, my $info ) = each %$symbols ) {
+while ( ( my $symbol, my $info ) = each %$globals ) {
   my @provides = keys %{$info->{provides}};
   my @requires = keys %{$info->{requires}};
+  my @shares = keys %{$info->{shares}};
 
-  if ( @provides == 0 ) {
-    # No object provides this symbol
+  if ( ( @requires > 0 ) && ( @provides == 0 ) && ( @shares == 0 ) ) {
+    # No object provides this symbol, but some objects require it.
     $problems->{$_}->{nonexistent}->{$symbol} = 1 foreach @requires;
-  } elsif ( @provides > 1 ) {
-    # Symbol defined in multiple objects
+  }
+
+  if ( ( @requires == 0 ) && ( @provides > 0 ) ) {
+    # No object requires this symbol, but some objects provide it.
+    foreach my $provide ( @provides ) {
+      if ( $provide eq "LINKER" ) {
+	# Linker-provided symbols are exempt from this check.
+      } elsif ( $info->{provides}->{$provide} =~ /^\.tbl\./ ) {
+	# Linker tables are exempt from this check.
+      } else {
+	$problems->{$provide}->{unused}->{$symbol} = 1;
+      }
+    }
+  }
+
+  if ( ( @shares > 0 ) && ( @provides > 0 ) ) {
+    # A shared symbol is being initialised by an object
+    $problems->{$_}->{shared}->{$symbol} = 1 foreach @provides;
+  }
+
+  if ( @provides > 1 ) {
+    # A non-shared symbol is defined in multiple objects
     $problems->{$_}->{multiples}->{$symbol} = 1 foreach @provides;
   }
-  if ( @requires == 0 ) {
-    # Symbol not required
-    $problems->{$_}->{unused}->{$symbol} = 1 foreach @provides;
+}
+
+# Check for excessively large local symbols.  Text and rodata symbols
+# are exempt from this check
+#
+while ( ( my $object, my $symbols ) = each %$symtab ) {
+  while ( ( my $symbol, my $info ) = each %$symbols ) {
+    if ( ( ! $info->{global} ) &&
+	 ( ( defined $info->{section} ) &&
+	   ! ( $info->{section} =~ /^(\.text|\.rodata)/ ) ) &&
+	 ( $info->{size} >= WARNING_SIZE ) ) {
+      $problems->{$object}->{large}->{$symbol} = 1;
+    }
   }
 }
 
@@ -55,18 +149,23 @@ foreach my $object ( sort keys %$problems ) {
   my @nonexistent = sort keys %{$problems->{$object}->{nonexistent}};
   my @multiples = sort keys %{$problems->{$object}->{multiples}};
   my @unused = sort keys %{$problems->{$object}->{unused}};
+  my @shared = sort keys %{$problems->{$object}->{shared}};
+  my @large = sort keys %{$problems->{$object}->{large}};
 
   print "WARN $object provides unused symbol $_\n" foreach @unused;
   $warnings += @unused;
+  print "WARN $object has large static symbol $_\n" foreach @large;
+  $warnings += @large;
   print "ERR  $object requires non-existent symbol $_\n" foreach @nonexistent;
   $errors += @nonexistent;
   foreach my $symbol ( @multiples ) {
     my @other_objects = sort grep { $_ ne $object }
-		        keys %{$symbols->{$symbol}->{provides}};
+		        keys %{$globals->{$symbol}->{provides}};
     print "ERR  $object provides symbol $symbol"
 	." (also provided by @other_objects)\n";
   }
   $errors += @multiples;
+  print "ERR  $object misuses shared symbol $_\n" foreach @shared;
 }
 
 print "$errors error(s), $warnings warning(s)\n";