#!/usr/bin/perl -w

# A script to get around some shortcomings in elf2e32, namely:

# - Returning 0 even when there are errors.

# - Excluding symbols from the dso file even when they are present in the ELF file.

# - Including symbols in the the dso file even when they are not present in the ELF file.

# - Overwriting the old dso file even when there are no changes (increases build time).

use File::Copy;

my @args = ();

my @definput;

my @defoutput;

my @dso;

my @tmpdso;

foreach (@ARGV) {

    if (/^--definput/o) {

        @definput = split('=', $_);

    } elsif (/^--defoutput/o) {

        @defoutput = split('=', $_);

    } elsif (/^--dso/o) {

        @dso = split('=', $_);

    } elsif (/^--tmpdso/o) {

        @tmpdso = split('=', $_);

        $tmpdso[0] = "--dso";

    } else {

        push(@args, $_);

    }

}

@definput = () if (!@definput || ! -e $definput[1]);

if (@dso && !@tmpdso || !@dso && @tmpdso) {

    print("--dso and --tmpdso must be used together.\n");

    exit 1;

}

my $buildingLibrary = (@defoutput && @dso) ? 1 : 0;

my $fixupFile = "";

my $runCount = 0;

my $returnCode = 0;

while (1) {

    if (++$runCount > 2) {

        print("Internal error in $0, link succeeded, but exports may be wrong.\n");

        last;

    }

    my $elf2e32Pipe;

    my $elf2e32Cmd = "elf2e32 @args"

         . " " . join("=", @definput)

         . " " . join("=", @defoutput)

         . " " . join("=", @tmpdso);

    open($elf2e32Pipe, "$elf2e32Cmd 2>&1 |") or die ("Could not run elf2e32");

    my %fixupSymbols;

    my $foundBrokenSymbols = 0;

    my $errors = 0;

    while (<$elf2e32Pipe>) {

        print;

        if (/Error:/io) {

            $errors = 1;

        } elsif (/symbol ([a-z0-9_]+) absent in the DEF file, but present in the ELF file/io) {

            $fixupSymbols{$1} = 1;

            $foundBrokenSymbols = 1;

        } elsif (/[0-9]+ Frozen Export\(s\) missing from the ELF file/io) {

            $foundBrokenSymbols = 1;

        }

    }

    close($elf2e32Pipe);

    if ($errors) {

        $returnCode = 1;

        last;

    }

    if ($buildingLibrary) {

        my $tmpDefFile;

        my $defFile;

        open($defFile, "< $defoutput[1]") or die("Could not open $defoutput[1]");

        open($tmpDefFile, "> $defoutput[1].tmp") or die("Could not open $defoutput[1].tmp");

        $fixupFile = "$defoutput[1].tmp";

        while (<$defFile>) {

            s/\r//;

            s/\n//;

            next if (/; NEW:/);

            if (/([a-z0-9_]+) @/i) {

                if (exists($fixupSymbols{$1})) {

                    s/ ABSENT//;

                } elsif (s/; MISSING://) {

                    s/$/ ABSENT/;

                }

            }

            print($tmpDefFile "$_\n");

        }

        close($defFile);

        close($tmpDefFile);

        $definput[1] = "$defoutput[1].tmp";

        if (!$foundBrokenSymbols || $errors) {

            last;

        }

        print("Rerunning elf2e32 due to DEF file / ELF file mismatch\n");

    } else {

        last;

    }

};

if ($fixupFile) {

    unlink($defoutput[1]);

    move($fixupFile, $defoutput[1]);

}

exit $returnCode if ($returnCode != 0);

if ($buildingLibrary) {

    my $differenceFound = 0;

    if (-e $dso[1]) {

        my $dsoFile;

        my $tmpdsoFile;

        my $dsoBuf;

        my $tmpdsoBuf;

        open($dsoFile, "< $dso[1]") or die("Could not open $dso[1]");

        open($tmpdsoFile, "< $tmpdso[1]") or die("Could not open $tmpdso[1]");

        binmode($dsoFile);

        binmode($tmpdsoFile);

        while(read($dsoFile, $dsoBuf, 4096) && read($tmpdsoFile, $tmpdsoBuf, 4096)) {

            if ($dsoBuf ne $tmpdsoBuf) {

                $differenceFound = 1;

            }

        }

        close($tmpdsoFile);

        close($dsoFile);

    } else {

        $differenceFound = 1;

    }

    if ($differenceFound) {

        copy($tmpdso[1], $dso[1]);

    }

}