use gas-preprocessor for ios

imported from https://github.com/yuvi/gas-preprocessor

1 files changed, 526 insertions, 0 deletions

diff --git a/tools/gas-preprocessor.pl b/tools/gas-preprocessor.pl
new file mode 100644
index 0000000..082f71b
--- /dev/null
+++ b/tools/gas-preprocessor.pl
@@ -0,0 +1,526 @@
+#!/usr/bin/env perl
+# by David Conrad
+# This code is licensed under GPLv2 or later; go to gnu.org to read it
+#  (not that it much matters for an asm preprocessor)
+# usage: set your assembler to be something like "perl gas-preprocessor.pl gcc"
+use strict;
+
+# Apple's gas is ancient and doesn't support modern preprocessing features like
+# .rept and has ugly macro syntax, among other things. Thus, this script
+# implements the subset of the gas preprocessor used by x264 and ffmpeg
+# that isn't supported by Apple's gas.
+
+my @gcc_cmd = @ARGV;
+my @preprocess_c_cmd;
+
+my $fix_unreq = $^O eq "darwin";
+
+if ($gcc_cmd[0] eq "-fix-unreq") {
+    $fix_unreq = 1;
+    shift @gcc_cmd;
+} elsif ($gcc_cmd[0] eq "-no-fix-unreq") {
+    $fix_unreq = 0;
+    shift @gcc_cmd;
+}
+
+if (grep /\.c$/, @gcc_cmd) {
+    # C file (inline asm?) - compile
+    @preprocess_c_cmd = (@gcc_cmd, "-S");
+} elsif (grep /\.[sS]$/, @gcc_cmd) {
+    # asm file, just do C preprocessor
+    @preprocess_c_cmd = (@gcc_cmd, "-E");
+} else {
+    die "Unrecognized input filetype";
+}
+
+# if compiling, avoid creating an output file named '-.o'
+if ((grep /^-c$/, @gcc_cmd) && !(grep /^-o/, @gcc_cmd)) {
+    foreach my $i (@gcc_cmd) {
+        if ($i =~ /\.[csS]$/) {
+            my $outputfile = $i;
+            $outputfile =~ s/\.[csS]$/.o/;
+            push(@gcc_cmd, "-o");
+            push(@gcc_cmd, $outputfile);
+            last;
+        }
+    }
+}
+@gcc_cmd = map { /\.[csS]$/ ? qw(-x assembler -) : $_ } @gcc_cmd;
+@preprocess_c_cmd = map { /\.o$/ ? "-" : $_ } @preprocess_c_cmd;
+
+my $comm;
+
+# detect architecture from gcc binary name
+if      ($gcc_cmd[0] =~ /arm/) {
+    $comm = '@';
+} elsif ($gcc_cmd[0] =~ /powerpc|ppc/) {
+    $comm = '#';
+}
+
+# look for -arch flag
+foreach my $i (1 .. $#gcc_cmd-1) {
+    if ($gcc_cmd[$i] eq "-arch") {
+        if ($gcc_cmd[$i+1] =~ /arm/) {
+            $comm = '@';
+        } elsif ($gcc_cmd[$i+1] =~ /powerpc|ppc/) {
+            $comm = '#';
+        }
+    }
+}
+
+# assume we're not cross-compiling if no -arch or the binary doesn't have the arch name
+if (!$comm) {
+    my $native_arch = qx/arch/;
+    if ($native_arch =~ /arm/) {
+        $comm = '@';
+    } elsif ($native_arch =~ /powerpc|ppc/) {
+        $comm = '#';
+    }
+}
+
+if (!$comm) {
+    die "Unable to identify target architecture";
+}
+
+my %ppc_spr = (ctr    => 9,
+               vrsave => 256);
+
+open(ASMFILE, "-|", @preprocess_c_cmd) || die "Error running preprocessor";
+
+my $current_macro = '';
+my $macro_level = 0;
+my %macro_lines;
+my %macro_args;
+my %macro_args_default;
+my $macro_count = 0;
+my $altmacro = 0;
+
+my @pass1_lines;
+my @ifstack;
+
+my %symbols;
+
+# pass 1: parse .macro
+# note that the handling of arguments is probably overly permissive vs. gas
+# but it should be the same for valid cases
+while (<ASMFILE>) {
+    # remove all comments (to avoid interfering with evaluating directives)
+    s/(?<!\\)$comm.*//x;
+
+    # comment out unsupported directives
+    s/\.type/$comm.type/x;
+    s/\.func/$comm.func/x;
+    s/\.endfunc/$comm.endfunc/x;
+    s/\.ltorg/$comm.ltorg/x;
+    s/\.size/$comm.size/x;
+    s/\.fpu/$comm.fpu/x;
+    s/\.arch/$comm.arch/x;
+    s/\.object_arch/$comm.object_arch/x;
+
+    # the syntax for these is a little different
+    s/\.global/.globl/x;
+    # also catch .section .rodata since the equivalent to .const_data is .section __DATA,__const
+    s/(.*)\.rodata/.const_data/x;
+    s/\.int/.long/x;
+    s/\.float/.single/x;
+
+    # catch unknown section names that aren't mach-o style (with a comma)
+    if (/.section ([^,]*)$/) {
+        die ".section $1 unsupported; figure out the mach-o section name and add it";
+    }
+
+    parse_line($_);
+}
+
+sub eval_expr {
+    my $expr = $_[0];
+    $expr =~ s/([A-Za-z._][A-Za-z0-9._]*)/$symbols{$1}/g;
+    eval $expr;
+}
+
+sub handle_if {
+    my $line = $_[0];
+    # handle .if directives; apple's assembler doesn't support important non-basic ones
+    # evaluating them is also needed to handle recursive macros
+    if ($line =~ /\.if(n?)([a-z]*)\s+(.*)/) {
+        my $result = $1 eq "n";
+        my $type   = $2;
+        my $expr   = $3;
+
+        if ($type eq "b") {
+            $expr =~ s/\s//g;
+            $result ^= $expr eq "";
+        } elsif ($type eq "c") {
+            if ($expr =~ /(.*)\s*,\s*(.*)/) {
+                $result ^= $1 eq $2;
+            } else {
+                die "argument to .ifc not recognized";
+            }
+        } elsif ($type eq "") {
+            $result ^= eval_expr($expr) != 0;
+        } elsif ($type eq "eq") {
+            $result = eval_expr($expr) == 0;
+        } elsif ($type eq "lt") {
+            $result = eval_expr($expr) < 0;
+        } else {
+	    chomp($line);
+            die "unhandled .if varient. \"$line\"";
+        }
+        push (@ifstack, $result);
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+sub parse_line {
+    my $line = @_[0];
+
+    # evaluate .if blocks
+    if (scalar(@ifstack)) {
+        if (/\.endif/) {
+            pop(@ifstack);
+            return;
+        } elsif ($line =~ /\.elseif\s+(.*)/) {
+            if ($ifstack[-1] == 0) {
+                $ifstack[-1] = !!eval_expr($1);
+            } elsif ($ifstack[-1] > 0) {
+                $ifstack[-1] = -$ifstack[-1];
+            }
+            return;
+        } elsif (/\.else/) {
+            $ifstack[-1] = !$ifstack[-1];
+            return;
+        } elsif (handle_if($line)) {
+            return;
+        }
+
+        # discard lines in false .if blocks
+        foreach my $i (0 .. $#ifstack) {
+            if ($ifstack[$i] <= 0) {
+                return;
+            }
+        }
+    }
+
+    if (/\.macro/) {
+        $macro_level++;
+        if ($macro_level > 1 && !$current_macro) {
+            die "nested macros but we don't have master macro";
+        }
+    } elsif (/\.endm/) {
+        $macro_level--;
+        if ($macro_level < 0) {
+            die "unmatched .endm";
+        } elsif ($macro_level == 0) {
+            $current_macro = '';
+            return;
+        }
+    }
+
+    if ($macro_level > 1) {
+        push(@{$macro_lines{$current_macro}}, $line);
+    } elsif ($macro_level == 0) {
+        expand_macros($line);
+    } else {
+        if ($line =~ /\.macro\s+([\d\w\.]+)\s*(.*)/) {
+            $current_macro = $1;
+
+            # commas in the argument list are optional, so only use whitespace as the separator
+            my $arglist = $2;
+            $arglist =~ s/,/ /g;
+
+            my @args = split(/\s+/, $arglist);
+            foreach my $i (0 .. $#args) {
+                my @argpair = split(/=/, $args[$i]);
+                $macro_args{$current_macro}[$i] = $argpair[0];
+                $argpair[0] =~ s/:vararg$//;
+                $macro_args_default{$current_macro}{$argpair[0]} = $argpair[1];
+            }
+            # ensure %macro_lines has the macro name added as a key
+            $macro_lines{$current_macro} = [];
+
+        } elsif ($current_macro) {
+            push(@{$macro_lines{$current_macro}}, $line);
+        } else {
+            die "macro level without a macro name";
+        }
+    }
+}
+
+sub expand_macros {
+    my $line = @_[0];
+
+    # handle .if directives; apple's assembler doesn't support important non-basic ones
+    # evaluating them is also needed to handle recursive macros
+    if (handle_if($line)) {
+        return;
+    }
+
+    if (/\.purgem\s+([\d\w\.]+)/) {
+        delete $macro_lines{$1};
+        delete $macro_args{$1};
+        delete $macro_args_default{$1};
+        return;
+    }
+
+    if ($line =~ /\.altmacro/) {
+        $altmacro = 1;
+        return;
+    }
+
+    if ($line =~ /\.noaltmacro/) {
+        $altmacro = 0;
+        return;
+    }
+
+    $line =~ s/\%([^,]*)/eval_expr($1)/eg if $altmacro;
+
+    if ($line =~ /\.set\s+(.*),\s*(.*)/) {
+        $symbols{$1} = eval_expr($2);
+    }
+
+    if ($line =~ /(\S+:|)\s*([\w\d\.]+)\s*(.*)/ && exists $macro_lines{$2}) {
+        push(@pass1_lines, $1);
+        my $macro = $2;
+
+        # commas are optional here too, but are syntactically important because
+        # parameters can be blank
+        my @arglist = split(/,/, $3);
+        my @args;
+        my @args_seperator;
+
+        my $comma_sep_required = 0;
+        foreach (@arglist) {
+            # allow arithmetic/shift operators in macro arguments
+            $_ =~ s/\s*(\+|-|\*|\/|<<|>>)\s*/$1/g;
+
+            my @whitespace_split = split(/\s+/, $_);
+            if (!@whitespace_split) {
+                push(@args, '');
+                push(@args_seperator, '');
+            } else {
+                foreach (@whitespace_split) {
+                        #print ("arglist = \"$_\"\n");
+                    if (length($_)) {
+                        push(@args, $_);
+                        my $sep = $comma_sep_required ? "," : " ";
+                        push(@args_seperator, $sep);
+                        #print ("sep = \"$sep\", arg = \"$_\"\n");
+                        $comma_sep_required = 0;
+                    }
+                }
+            }
+
+            $comma_sep_required = 1;
+        }
+
+        my %replacements;
+        if ($macro_args_default{$macro}){
+            %replacements = %{$macro_args_default{$macro}};
+        }
+
+        # construct hashtable of text to replace
+        foreach my $i (0 .. $#args) {
+            my $argname = $macro_args{$macro}[$i];
+            my @macro_args = @{ $macro_args{$macro} };
+            if ($args[$i] =~ m/=/) {
+                # arg=val references the argument name
+                # XXX: I'm not sure what the expected behaviour if a lot of
+                # these are mixed with unnamed args
+                my @named_arg = split(/=/, $args[$i]);
+                $replacements{$named_arg[0]} = $named_arg[1];
+            } elsif ($i > $#{$macro_args{$macro}}) {
+                # more args given than the macro has named args
+                # XXX: is vararg allowed on arguments before the last?
+                $argname = $macro_args{$macro}[-1];
+                if ($argname =~ s/:vararg$//) {
+                    #print "macro = $macro, args[$i] = $args[$i], args_seperator=@args_seperator, argname = $argname, arglist[$i] = $arglist[$i], arglist = @arglist, args=@args, macro_args=@macro_args\n";
+                    #$replacements{$argname} .= ", $args[$i]";
+                    $replacements{$argname} .= "$args_seperator[$i] $args[$i]";
+                } else {
+                    die "Too many arguments to macro $macro";
+                }
+            } else {
+                $argname =~ s/:vararg$//;
+                $replacements{$argname} = $args[$i];
+            }
+        }
+
+        my $count = $macro_count++;
+
+        # apply replacements as regex
+        foreach (@{$macro_lines{$macro}}) {
+            my $macro_line = $_;
+            # do replacements by longest first, this avoids wrong replacement
+            # when argument names are subsets of each other
+            foreach (reverse sort {length $a <=> length $b} keys %replacements) {
+                $macro_line =~ s/\\$_/$replacements{$_}/g;
+            }
+            $macro_line =~ s/\\\@/$count/g;
+            $macro_line =~ s/\\\(\)//g;     # remove \()
+            parse_line($macro_line);
+        }
+    } else {
+        push(@pass1_lines, $line);
+    }
+}
+
+close(ASMFILE) or exit 1;
+open(ASMFILE, "|-", @gcc_cmd) or die "Error running assembler";
+#open(ASMFILE, ">/tmp/a.S") or die "Error running assembler";
+
+my @sections;
+my $num_repts;
+my $rept_lines;
+
+my %literal_labels;     # for ldr <reg>, =<expr>
+my $literal_num = 0;
+
+my $thumb = 0;
+
+my %thumb_labels;
+my %call_targets;
+
+my $in_irp = 0;
+my @irp_args;
+my $irp_param;
+
+# pass 2: parse .rept and .if variants
+# NOTE: since we don't implement a proper parser, using .rept with a
+# variable assigned from .set is not supported
+foreach my $line (@pass1_lines) {
+    # handle .previous (only with regard to .section not .subsection)
+    if ($line =~ /\.(section|text|const_data)/) {
+        push(@sections, $line);
+    } elsif ($line =~ /\.previous/) {
+        if (!$sections[-2]) {
+            die ".previous without a previous section";
+        }
+        $line = $sections[-2];
+        push(@sections, $line);
+    }
+
+    $thumb = 1 if $line =~ /\.code\s+16|\.thumb/;
+    $thumb = 0 if $line =~ /\.code\s+32|\.arm/;
+
+    # handle ldr <reg>, =<expr>
+    if ($line =~ /(.*)\s*ldr([\w\s\d]+)\s*,\s*=(.*)/) {
+        my $label = $literal_labels{$3};
+        if (!$label) {
+            $label = "Literal_$literal_num";
+            $literal_num++;
+            $literal_labels{$3} = $label;
+        }
+        $line = "$1 ldr$2, $label\n";
+    } elsif ($line =~ /\.ltorg/) {
+        $line .= ".align 2\n";
+        foreach my $literal (keys %literal_labels) {
+            $line .= "$literal_labels{$literal}:\n .word $literal\n";
+        }
+        %literal_labels = ();
+    }
+
+    # thumb add with large immediate needs explicit add.w
+    if ($thumb and $line =~ /add\s+.*#([^@]+)/) {
+        $line =~ s/add/add.w/ if eval_expr($1) > 255;
+    }
+
+    # mach-o local symbol names start with L (no dot)
+    $line =~ s/(?<!\w)\.(L\w+)/$1/g;
+
+    if ($thumb and $line =~ /^\s*(\w+)\s*:/) {
+        $thumb_labels{$1}++;
+    }
+
+    if ($line =~ /^\s*((\w+:)?blx?|\.globl)\s+(\w+)/) {
+        $call_targets{$3}++;
+    }
+
+    # @l -> lo16()  @ha -> ha16()
+    $line =~ s/,\s+([^,]+)\@l\b/, lo16($1)/g;
+    $line =~ s/,\s+([^,]+)\@ha\b/, ha16($1)/g;
+
+    # move to/from SPR
+    if ($line =~ /(\s+)(m[ft])([a-z]+)\s+(\w+)/ and exists $ppc_spr{$3}) {
+        if ($2 eq 'mt') {
+            $line = "$1${2}spr $ppc_spr{$3}, $4\n";
+        } else {
+            $line = "$1${2}spr $4, $ppc_spr{$3}\n";
+        }
+    }
+
+    # old gas versions store upper and lower case names on .req,
+    # but they remove only one on .unreq
+    if ($fix_unreq) {
+        if ($line =~ /\.unreq\s+(.*)/) {
+            $line = ".unreq " . lc($1) . "\n";
+            print ASMFILE ".unreq " . uc($1) . "\n";
+        }
+    }
+
+    if ($line =~ /\.rept\s+(.*)/) {
+        $num_repts = $1;
+        $rept_lines = "\n";
+
+        # handle the possibility of repeating another directive on the same line
+        # .endr on the same line is not valid, I don't know if a non-directive is
+        if ($num_repts =~ s/(\.\w+.*)//) {
+            $rept_lines .= "$1\n";
+        }
+        $num_repts = eval($num_repts);
+    } elsif ($line =~ /\.irp\s+([\d\w\.]+)\s*(.*)/) {
+        $in_irp = 1;
+        $num_repts = 1;
+        $rept_lines = "\n";
+        $irp_param = $1;
+
+        # only use whitespace as the separator
+        my $irp_arglist = $2;
+        $irp_arglist =~ s/,/ /g;
+        $irp_arglist =~ s/^\s+//;
+        @irp_args = split(/\s+/, $irp_arglist);
+    } elsif ($line =~ /\.irpc\s+([\d\w\.]+)\s*(.*)/) {
+        $in_irp = 1;
+        $num_repts = 1;
+        $rept_lines = "\n";
+        $irp_param = $1;
+
+        my $irp_arglist = $2;
+        $irp_arglist =~ s/,/ /g;
+        $irp_arglist =~ s/^\s+//;
+        @irp_args = split(//, $irp_arglist);
+    } elsif ($line =~ /\.endr/) {
+        if ($in_irp != 0) {
+            foreach my $i (@irp_args) {
+                my $line = $rept_lines;
+                $line =~ s/\\$irp_param/$i/g;
+                $line =~ s/\\\(\)//g;     # remove \()
+                print ASMFILE $line;
+            }
+        } else {
+            for (1 .. $num_repts) {
+                print ASMFILE $rept_lines;
+            }
+        }
+        $rept_lines = '';
+        $in_irp = 0;
+        @irp_args = '';
+    } elsif ($rept_lines) {
+        $rept_lines .= $line;
+    } else {
+        print ASMFILE $line;
+    }
+}
+
+print ASMFILE ".text\n";
+print ASMFILE ".align 2\n";
+foreach my $literal (keys %literal_labels) {
+    print ASMFILE "$literal_labels{$literal}:\n .word $literal\n";
+}
+
+map print(ASMFILE ".thumb_func $_\n"),
+    grep exists $thumb_labels{$_}, keys %call_targets;
+
+close(ASMFILE) or exit 1;
+#exit 1