#! /usr/bin/env perl
##
## Copyright (C) by Argonne National Laboratory
##     See COPYRIGHT in top-level directory
##

# f77tof90 indir outdir [ Makefile-template [Make-Append] ]
# For each file in indir/*.[fF], create a corresponding file in outdir
# with .f90/.F90, and with any include "mpif.h" replaced with use mpi
# It also changes to the new comment style, because some compilers
# use the comment style to choose other features of the language
#
# We also allow the file name to be modified to help out Windows, since
# programs in a project need to have distinct names
#
use strict;
use warnings;

my ($indir, $outdir, $makeTemplate, $makeAppend) = @ARGV;
my $convertToFreeForm    = 1;
my $convertToNewComments = 1;
# Including a newline variable allows us to handle Unix and DOS source files
my $newline = "\n";

my %replaceInclude = (
    'iodisp' => 'integer (kind=MPI_OFFSET_KIND) disp',
    'ioaint' => 'integer (kind=MPI_ADDRESS_KIND) aint',
    'iooffset' => 'integer (kind=MPI_OFFSET_KIND) offset',
    'type1aint' => 'integer (kind=MPI_ADDRESS_KIND) aint', 
    'typeaints' => 'integer (kind=MPI_ADDRESS_KIND) aint, aintv(max_asizev)', 
    'attr1aints' => 'integer (kind=MPI_ADDRESS_KIND) extrastate, valin, valout, val',
    'attraints' => 'integer (kind=MPI_ADDRESS_KIND) extrastate, valin, valout, val',
    'addsize' => 'integer (kind=MPI_ADDRESS_KIND) asize',
    'add1size' => 'integer (kind=MPI_ADDRESS_KIND) asize',
);

my %excludePrograms = ();
my $debugReplace = 0;
my $reportSkipped = 1;

# --------------------------------------------------------------------------
# Check the input arguments
if ($indir eq "" || $outdir eq "") {
    print STDERR "Usage: f77tof90 indir outdir [ makefile-template ]\n";
    exit 1;
}
if ( ! -d $indir) {
    print STDERR "Input directory $indir does not exist\n";
    exit 1;
}
if (! -d $outdir) {
    print STDERR "Output directory $outdir does not exist\n";
    exit 1;
}
# --------------------------------------------------------------------------


# --------------------------------------------------------------------------
opendir( DIR, "$indir" );
my @filelist = ();
while (my $file = readdir(DIR)) {
    # Extract the extension
    if ($file =~ /^(.*)\.([^\.]*)$/) {
        my ($name, $ext) = ($1, $2);
	# Special handling for C files, if any
	if ($ext eq "c") {
	    my $name90 = $name;
            # don't transform "ctypesfromc" to "ctypesf90romc"
            if ($name ne "ctypesfromc") {
                $name90 =~ s/f/f90/g;
            }
	    &ConvertCFile( "$indir/$file", "$outdir/$name90.c.new" );
	    &ReplaceIfDifferent( "$outdir/$name90.c", 
				 "$outdir/$name90.c.new" );
	    next;
	}
	# Skip if the file isn't a Fortran source file
	if ($ext ne "f" && $ext ne "F") { next; }
	&ConvertToF90( "$indir/$file", "$outdir/${name}90.${ext}90.new" );
	&ReplaceIfDifferent( "$outdir/${name}90.${ext}90", 
			     "$outdir/${name}90.${ext}90.new" );
	$filelist[$#filelist+1] = $file;
    }
}
closedir( DIR );

# &CreateMakefile( "filelist", $outdir );
if (defined($makeTemplate) && $makeTemplate ne "" &&
    -s "$indir/$makeTemplate") {
    &ConvertMakefile( $indir, $outdir, $makeTemplate );
    if (defined($makeAppend) && -s "$outdir/$makeAppend") {
	# If there is a makeAppend in the output directory, then 
	# append that to the generated makefile
	&AppendFile( "$outdir/$makeAppend", "$outdir/$makeTemplate.new" );
    }
    &ReplaceIfDifferent( "$outdir/$makeTemplate", 
			 "$outdir/$makeTemplate.new" );

    # unconditionally update the stamp file to assist the maintainer rebuild
    # rules
    open(STAMP, '>', "$outdir/Makefile.am-stamp");
    print STAMP localtime()."\n";
    close(STAMP);
}
if (-s "$indir/testlist" || -s "$indir/testlist.in") {
    # We allow both testlist.in and testlist as source files;
    # testlist.in gets priority
    my $filename = "testlist";
    if (-s "$indir/testlist.in") {
	$filename = "testlist.in";
    }
    &ConvertTestlist( $indir, $outdir, $filename );
    
    if (-s "$outdir/testlist.ap") {
	&AppendFile( "$outdir/testlist.ap", "$outdir/$filename.new" );
    }
    &ReplaceIfDifferent( "$outdir/$filename", "$outdir/$filename.new" );
}

exit 0;

# -----------------------------------------------------------------------------

sub ConvertToF90 {
    my $infile = $_[0];
    my $outfile = $_[1];
    
    open (INF, "<$infile" ) || die "Could not open $infile\n";
    open (OUTF, ">$outfile" ) || die "Could not open $outfile\n";

    print OUTF "! This file created from $infile with f77tof90\n";
    my $lastline = "";
    my $firstline = 1;
    my $scope = ""; # program or subroutine
    while (<INF>) {
	if (/\r/) { $newline = "\r\n"; }
	# Remove any end-of-line characters
	s/[\r\n]*//g;
        if (/^\s*(program|subroutine)\s*(\w+)/i) {
            $scope = lc($1) . " " . lc($2);
        }
        # The implicit none must not come before the use mpi statement,
	# but in F77, it must come before the include mpif.h statement.
	# Rather than try and fix this, rely on the F77 versions to 
	# catch undeclared variables
        if (/IMPLICIT\s+NONE/i) {
            next;
        }
	if (/^(\s*)include\s+[\'\"]mpif\.h/) {
            my $sp = $1;
            if ($scope =~ /subroutine (mpi_\w+)/) {
                $_ = $sp . "use mpi, skip_$1 => $1";
            } else {
                $_ = $sp . "use mpi";
            }
	}
	# Allow the insertion of Fortran 90 only statements, such as
	# interface definitions
        if (/^CF90/) {
	    s/^CF90/    /;
	}
        # Remove lines used only for F77, such as external MPI function declarations
        if (/!\s*F77ONLY\s*$/i) {
            $_ = "";
        }
	# Since we use interface statements for the error handlers,
	# remove their external declaration
	if (/^\s+external myerrhanfunc/) {
	    s/^\s/!/;
	}
	if ($convertToNewComments) {
	    s/^C/!/;
	    s/^c/!/;
	}	
	# Update the special includes that are used to provide 
	# address or offset sized types with ones the use the
	# Fortran90 KIND style
	if (/^(\s*)include\s+[\'\"]([\/\.\w]+)\.h[\"\']/) {
	    my $leading     = $1;
	    my $includename = $2;
	    if (defined($replaceInclude{$includename})) {
		$_ = $leading . $replaceInclude{$includename} . "\n";
	    }
	}

	# We need to handle the special case of the program
	# name in spawn commands
	if (/(.*)\"([\.\/\w]*spawn[^\"]*)\"(.*)/) {
	    my $before = $1;
	    my $name = $2;
	    my $after = $3;
	    $_ = $before . "\"" . $name . "90" . "\"" . $after;
	}

	# We could also detect continuations in column six and 
	# convert to free-form input by holding one line back.
	if ($convertToFreeForm) {
	    if (/^     \S(.*)/) {
		my $leftover = $1;
		# This line contains a continuation marker
		# Add a continuation marker to the previous line if
		# it doesn't already have one
		if (! ($lastline =~ /\&\s*$/) ) {
	  	    $lastline .= " &";	   
		}
		$_ = "      \&$leftover";
	    }
	}
	print OUTF "$lastline$newline" if (! $firstline);
	$firstline = 0;
	$lastline = $_;
    }
    print OUTF "$lastline$newline";

    close (INF);
    close (OUTF);
}

#
# A very simple routine for creating a version of a C file that refers
# to F90 instead of F77.
sub ConvertCFile {
    my $infile = $_[0];
    my $outfile = $_[1];
    
    open (INF, "<$infile" ) || die "Could not open $infile\n";
    open (OUTF, ">$outfile" ) || die "Could not open $outfile\n";

    print OUTF "/* This file created from $infile with f77tof90 */\n";
    while (<INF>) {
	if (/\r/) { $newline = "\r\n"; }
	# Remove any end-of-line characters
	s/[\r\n]*//g;
	# replace F77 with F90, mostly for CPP tests, except for name
	# mapping
	if (! /F77_NAME/) {
	    s/F77/F90/g;
	}
	print OUTF "$_$newline";
    }

    close (INF);
    close (OUTF);
}

# Create a makefile from a template.  Replace @EXECS@ with the programs
# in the filelist.
# CreateMakefile( "filelist", $outdir )
sub CreateMakefile {
    my $filelist = $_[0];
    my $outdir   = $_[1];

    print STDERR "This function is not implemented\n";
    return 0;
}

#
# Take an existing makefile and perform the following transformations:
# .f -> .f90, .F -> .F90
# Others as necessary
# ConvertMakefile( indir, outdir, filename )
# By providing the filename, we can accept Makefile, Makefile.in, Makefile.ap,
# Makefile.sm, or even nonstandard names such as buildscript.
sub ConvertMakefile {
    my ($indir, $outdir, $filename) = @_;
    %excludePrograms = ();
    my $saw_maintainercleanfiles = 0;
    my $saw_extra_dist = 0;

    open( INF, "<$indir/$filename" ) || die "Cannot open $indir/$filename\n";
    open( OUTF, ">$outdir/$filename.new" ) || die "Cannot open $outdir/$filename.new\n";
    print OUTF "# This $filename generated automatically by f77tof90\n";
    print OUTF "# from $indir/$filename.  DO NOT EDIT\n"; 
    while (<INF>) {
        if (not m/^\s*#/ and m/MAINTAINERCLEANFILES/) {
            $saw_maintainercleanfiles = 1;
        }
        if (not m/^\s*#/ and m/EXTRA_DIST/) {
            $saw_extra_dist = 1;
        }

        # First, check for sources that are not present.  These
	# may be derived files (see f77/io for an example).  For now,
	# we'll skip these unless they are explicitly expected to not be present
        # (by the presence of a "nodist_" prefix.
	if (/^(nodist_)?(\w+)_SOURCES\s*=\s*(\w+\.f)/) {
            my $nodist     = $1;
	    my $sourcebase = $2;
	    my $sourcename = $3;
	    if (not $nodist and ! -s "$indir/$sourcename") {
		print "Skipping source file $indir/$sourcename because it is not present\n" if $reportSkipped;
		$excludePrograms{$sourcebase} = 1;
		next; 
	    }
	}

        # Headers like f77/spawn/type1aints.h are not used in the f90 tests.
        # They are instead replaced with appropriate "kind=" type declarations
        # in a different part of this script.  So we drop any lines that add
        # dependencies on a header.
        if (m/^\w+f\.\$\(OBJEXT\):.*\.h/) {
            my $chomped = $_;
            chomp $_;
            next;
        }

        # convert program names from foof.f to foof90.f90
        s/f_SOURCES/f90_SOURCES/g;
        s/f_DEPENDENCIES/f90_DEPENDENCIES/g;
	if (/f\.f/) {
	    s/f\.f/f90.f90/g;
	}
	else {
	    # Move files to f90
	    s/\.f/.f90/g;
	}
	s/mtestf\.o/mtestf90.o/;
	s/\.F/.F90/g;
	s/f77/f90/g;
	s/F77/FC/g;
	# Update any per-program LDADD values
        s/f_LDADD/f90_LDADD/g;
	#
	# Handle special cases:  
	# Force the c2f2c test to use the f90 compiler
	s/c2f2cf90_SOURCES.*/c2f2cf90_SOURCES = c2f2cf90.f90 c2f902c.c/;
	s/c2f2ciof90_SOURCES.*/c2f2ciof90_SOURCES = c2f2ciof90.f90 c2f902cio.c/;
#	s/c2f2ciof90_LDADD/c2f2cfio90_LDADD/g;
	s/c2f2cwinf90_SOURCES.*/c2f2cwinf90_SOURCES = c2f2cwinf90.f90 c2f902cwin.c/;
        s/c2fmult/c2f90mult/g;

	if (/EXTRA_PROGRAMS/) {
	    s/allocmemf/allocmemf90/;   # allocmemf test is special 
	}
	# Handle the special case of C programs (used for f2c/c2f testing)
	if (/^(\w+)_SOURCES(\s*=\s*)(\w+)\.c\s*$/) {
	    my $progname = $1;
	    my $spacing  = $2;
	    my $name     = $3;
            if ($name !~ m/ctypesfromc/) {
                $name =~ s/f(?!90)/f90/;
                $progname =~ s/f(?!90)/f90/;
                $_ = "$progname" . "_SOURCES" . $spacing . $name . ".c\n";
            }
	}

        # Catch any bare "Xf" tests listed in noinst_PROGRAMS or
        # EXTRA_PROGRAMS.  Check for "Xf.f" to avoid substituting any random
        # word that ends in "f".  We also cheat a bit and look into the
        # ioharness.defn in the indir directory for valid file names.
        if (not m/^\s*#/) {
            while (m/\b(\w+f)\b/g) {
                my $word = $1;
                next if $word eq "if" or $word eq "rf" or $word eq "endif"; # filter out some noise
                if (-e "$indir/${word}.f" or
                    0 == system(qq(grep 'TESTDEFN filename="${word}\\.f"' '$indir/ioharness.defn' >/dev/null 2>&1)))
                {
                    s/\b${word}\b/${word}90/g;
                }
                else
                {
                    print "Skipping word '${word}' because file $indir/${word}.f is not present\n" if $reportSkipped;
                }
            }
        }

        # f90 makefiles should use the corresponding common automake fragment
        s/Makefile_f77.mtest/Makefile_f90.mtest/g;

	# Eventually need some way to update directory paths (particularly
	# relative ones) and add F90 compile rules when not present.
	print OUTF $_;
    }

    my $mcf_plus = '';
    if ($saw_maintainercleanfiles) {
        $mcf_plus = '+';
    }
    my $ed_plus = '';
    if ($saw_extra_dist) {
        $ed_plus = '+';
    }

    my $testlist_ap = '';
    if (-f "${outdir}/testlist.ap") {
        $testlist_ap = 'testlist.ap';
    }
    my $makefile_ap = '';
    if (-f "${outdir}/Makefile.ap") {
        $makefile_ap = 'Makefile.ap';
    }

    # append a rule to help remake the f90 Makefile.am if the f77 Makefile.am is
    # updated
    print OUTF <<EOT;

if MAINTAINER_MODE

# f77tof90 only replaces output files if the contents differ, so we must use a
# separate timestamp file in order avoid constantly trying to remake the f90
# copy of the Makefile when the f77 copy is updated in a way that does not
# change its contents
\$(srcdir)/Makefile.am: \$(srcdir)/Makefile.am-stamp

\$(srcdir)/Makefile.am-stamp: \$(top_srcdir)/${indir}/Makefile.am \$(top_srcdir)/maint/f77tof90
\t( cd \$(top_srcdir) && ./maint/f77tof90 ${indir} ${outdir} Makefile.am Makefile.ap )

MAINTAINERCLEANFILES ${mcf_plus}= Makefile.am-stamp
EXTRA_DIST ${ed_plus}= Makefile.am-stamp ${testlist_ap} ${makefile_ap}

endif MAINTAINER_MODE

EOT

    close( INF );
    close( OUTF );
    # The check on a file change is handled in the routine that calls this
    # because we may append to this file first.
}

# Append infile to the end of inout file
#( infile, inoutfile )
sub AppendFile { 
    my $infile = $_[0];
    my $outfile = $_[1];
    
    open( INA, "<$infile" ) || die "Cannot open $infile\n";
    open( OUTA, ">>$outfile" ) || die "Cannot open $outfile\n";
    while (<INA>) {
        print OUTA $_;
    }
    close(INA);
    close(OUTA);
}

#
# Replace old file with new file only if new file is different
# Otherwise, remove new filename 
sub ReplaceIfDifferent {
    my ($oldfilename,$newfilename) = @_;
    my $rc = 1;
    if (-s $oldfilename) { 
	$rc = system "cmp -s $newfilename $oldfilename";
	$rc >>= 8;   # Shift right to get exit status
    }
    if ($rc != 0) {
	print STDERR "Replacing $oldfilename\n";
	if ($debugReplace && -s $oldfilename) {
	    print STDERR "Differences are:";
	    system "diff $newfilename $oldfilename";
	}
	# The files differ.  Replace the old file 
	# with the new one
	if (-s $oldfilename) {
	    unlink $oldfilename;
	}
	rename $newfilename, $oldfilename || 
	    die "Could not replace $oldfilename";
    }
    else {
	unlink $newfilename;
    }
}

# Change the names of the tests.  Remove any that were skipped from the 
# Makefile.  Check for a  testlist.in before testlist
sub ConvertTestlist {
    my ($indir, $outdir, $filename) = @_;

    open( INF, "<$indir/$filename" ) || die "Cannot open $indir/$filename\n";
    open( OUTF, ">$outdir/$filename.new" ) || die "Cannot open $outdir/$filename.new\n";
    print OUTF "# This file generated by f77tof90\n";
    while (<INF>) {
	if (/^(\w+)\s/) {
	    my $sourcebase = $1;
	    if (defined($excludePrograms{$sourcebase})) { next; }
	}
	if (/^(\w+f)\s+(.*)/) {
	    $_ = $1 . "90 "  . $2 . "\n";
	}
	elsif (/^c2fmult(\w*)\s+(.*)/) {
	    # This is a special case for programs that are not Fortran
	    # programs but are part of the Fortran tests; principally, these
	    # are the tests of MPI handle conversion
	    # note the \w* instead of \w+; this allows us to match both
	    # c2fmult.c and c2fmultio.c
	    $_ = "c2f90mult$1 $2\n";
	}
	elsif (/^\@ALLOCMEMF\@/) {
	    # This is a special case for an optional feature (using
	    # Cray-style pointers for MPI_Alloc_mem).
	    $_ = "\@ALLOCMEMFC\@\n";
	}
	elsif (/^(\@\w+\@)(\s*\w+f)\s+(.*)/) {
	    # This handles the case where an autoconf variable in the
            # testlist.in file is used to optionally comment out a test
	    $_ = $1 . $2 . "90 "  . $3 . "\n";
	}
	print OUTF $_;
    }
    close INF;
    close OUTF;

}