#!/usr/bin/perl -w
# -----------------------------------------------------------------------------

my $cc = $ENV{'REAL_CC'} || 'cc';
my $check = $ENV{'CHECK'} || 'check';

my $m64 = 0;
my $has_specs = 0;
my $do_check = 0;
my $do_compile = 1;
my $verbose = 0;

foreach (@ARGV) {
    # Look for a .c file.  We don't want to run the checker on .o or .so files
    # in the link run.  (This simplistic check knows nothing about options
    # with arguments, but it seems to do the job.)
    $do_check = 1 if /^[^-].*\.c$/;

    # Ditto for stdin.
    $do_check = 1 if $_ eq '-';

    $m64 = 1 if /^-m64$/;

    if (/^-specs=(.*)$/) {
	$check .= &add_specs ($1);
	$has_specs = 1;
	next;
    }

    if ($_ eq '-no-compile') {
	$do_compile = 0;
	next;
    }

    # If someone adds "-E", don't pre-process twice.
    $do_compile = 0 if $_ eq '-E';

    $verbose = 1 if $_ eq '-v';

    my $this_arg = ' ' . &quote_arg ($_);
    $cc .= $this_arg unless &check_only_option ($_);
    $check .= $this_arg;
}

if ($do_check) {
    if (!$has_specs) {
	$check .= &add_specs ('host_arch_specs');
	$check .= &add_specs ('host_os_specs');
    }
    print "$check\n" if $verbose;
#    exit 1;
    system ($check);
}

if ($do_compile) {
    print "$cc\n" if $verbose;
    exec ($cc);
}

exit 0;

# -----------------------------------------------------------------------------
# Check if an option is for "check" only.

sub check_only_option {
    my ($arg) = @_;
    return 1 if $arg =~ /^-W(no-?)?(default-bitfield-sig|bitwise|typesign)$/;
    return 0;
}

# -----------------------------------------------------------------------------
# Simple arg-quoting function.  Just adds backslashes when needed.

sub quote_arg {
    my ($arg) = @_;
    return "''" if $arg eq '';
    return join ('',
		 map {
		     m|^[-a-zA-Z0-9._/,=]+$| ? $_ : "\\" . $_;
		 } (split (//, $arg)));
}

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

sub integer_types {
    my ($char,@dummy) = @_;

    my %pow2m1 =
	(8 => '127',
	 16 => '32767',
	 32 => '2147483647',
	 64 => '9223372036854775807',
	 );
    my @types = (['SCHAR',''], ['SHRT',''], ['INT',''], ['LONG','L'], ['LONG_LONG','LL']);

    my $result = " -D__CHAR_BIT__=$char";
    while (@types) {
	my $bits = shift @_;
	my ($name,$suffix) = @{ shift @types };
	die "$0: wierd number of bits." unless exists $pow2m1{$bits};
	$result .= " -D__${name}_MAX__=" . $pow2m1{$bits} . $suffix;
    }
    return $result;
}

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

sub float_types {
    my ($has_inf,$has_qnan,$dec_dig,@bitsizes) = @_;
    my $result = " -D__FLT_RADIX__=2";
    $result .= " -D__FINITE_MATH_ONLY__=" . ($has_inf || $has_qnan ? '0' : '1');
    $result .= " -D__DECIMAL_DIG__=$dec_dig";

    my %constants =
	(24 =>
	 {
	     'MIN' => '1.17549435e-38',
	     'MAX' => '3.40282347e+38',
	     'EPSILON' => '1.19209290e-7',
	     'DENORM_MIN' => '1.40129846e-45',
	 },
	 53 =>
	 {
	     'MIN' => '2.2250738585072014e-308',
	     'MAX' => '1.7976931348623157e+308',
	     'EPSILON' => '2.2204460492503131e-16',
	     'DENORM_MIN' => '4.9406564584124654e-324',
	 },
	 64 =>
	 {
	     'MIN' => '3.36210314311209350626e-4932',
	     'MAX' => '1.18973149535723176502e+4932',
	     'EPSILON' => '1.08420217248550443401e-19',
	     'DENORM_MIN' => '3.64519953188247460253e-4951',
	 },
	 113 =>
	 {
	     'MIN' => '3.36210314311209350626267781732175260e-4932',
	     'MAX' => '1.18973149535723176508575932662800702e+4932',
	     'EPSILON' => '1.92592994438723585305597794258492732e-34',
	     'DENORM_MIN' => '6.47517511943802511092443895822764655e-4966',
	 },
	 );	     

    my @types = (['FLT','F'], ['DBL',''], ['LDBL','L']);
    while (@types) {
	my ($mant_bits,$exp_bits) = @{ shift @bitsizes };
	my ($name,$suffix) = @{ shift @types };

	my $h = $constants{$mant_bits};
	die "$0: wierd number of mantissa bits." unless $h;

	my $mant_dig = int (($mant_bits - 1) * log (2) / log (10));
	my $max_exp = 1 << ($exp_bits - 1);
	my $min_exp = 3 - $max_exp;
	my $max_10_exp = int ($max_exp * log (2) / log (10));
	my $min_10_exp = -int (-$min_exp * log (2) / log (10));

	$result .= " -D__${name}_MANT_DIG__=$mant_bits";
	$result .= " -D__${name}_DIG__=$mant_dig";
	$result .= " -D__${name}_MIN_EXP__='($min_exp)'";
	$result .= " -D__${name}_MAX_EXP__=$max_exp";
	$result .= " -D__${name}_MIN_10_EXP__='($min_10_exp)'";
	$result .= " -D__${name}_MAX_10_EXP__=$max_10_exp";
	$result .= " -D__${name}_HAS_INFINITY__=" . ($has_inf ? '1' : '0');
	$result .= " -D__${name}_HAS_QUIET_NAN__=" . ($has_qnan ? '1' : '0');;

	foreach my $inf (sort keys %$h) {
	    $result .= " -D__${name}_${inf}__=" . $h->{$inf} . $suffix;
	}
    }
    return $result;
}

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

sub define_size_t {
    my ($text) = @_;
    # We have to undef in order to override check's internal definition.
    return ' -U__SIZE_TYPE__ ' . &quote_arg ("-D__SIZE_TYPE__=$text");
}

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

sub add_specs {
    my ($spec) = @_;
    if ($spec eq 'sunos') {
	return &add_specs ('unix') .
	    ' -D__sun__=1 -D__sun=1 -Dsun=1' .
	    ' -D__svr4__=1 -DSVR4=1' .
	    ' -D__STDC__=0' .
	    ' -D_REENTRANT' .
	    ' -D_SOLARIS_THREADS' .
	    ' -DNULL="((void *)0)"';
    } elsif ($spec eq 'linux') {
	return &add_specs ('unix') .
	    ' -D__linux__=1 -D__linux=1 -Dlinux=linux' .
	    ' -D__STDC__=1';
    } elsif ($spec eq 'unix') {
	return ' -Dunix=1 -D__unix=1 -D__unix__=1';
    } elsif ($spec eq 'i86') {
	return (' -Di386=1 -D__i386=1 -D__i386__=1' .
		&integer_types (8, 16, 32, $m64 ? 64 : 32, 64) .
		&float_types (1, 1, 21, [24,8], [53,11], [64,15]) .
		&define_size_t ($m64 ? "long unsigned int" : "unsigned int"));
    } elsif ($spec eq 'sparc') {
	return (' -Dsparc=1 -D__sparc=1 -D__sparc__=1' .
		&integer_types (8, 16, 32, $m64 ? 64 : 32, 64) .
		&float_types (1, 1, 33, [24,8], [53,11], [113,15]) .
		&define_size_t ($m64 ? "long unsigned int" : "unsigned int"));
    } elsif ($spec eq 'host_os_specs') {
	my $os = `uname -s`;
	chomp $os;
	return &add_specs (lc $os);
    } elsif ($spec eq 'host_arch_specs') {
	my $arch = `uname -m`;
	chomp $arch;
	if ($arch =~ /^(i.?86|athlon)$/i) {
	    return &add_specs ('i86');
	} elsif ($arch =~ /^(sun4u)$/i) {
	    return &add_specs ('sparc');
	}
    } else {
	die "$0: invalid specs: $spec\n";
    }
}

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