From 9bbfe9592511d6cb6c33ab06af370eaf69e9ab6c Mon Sep 17 00:00:00 2001
From: jiangzhengwenjz <jiangzhengwenjzw@qq.com>
Date: Fri, 27 Mar 2020 11:48:34 +0800
Subject: [PATCH] calcrom.pl from pret/pokefirered

---
 calcrom.pl                | 152 ++++++++++++++++++++++++++++++++++++++
 tools/preproc/charmap.cpp |   7 +-
 2 files changed, 158 insertions(+), 1 deletion(-)
 create mode 100644 calcrom.pl

diff --git a/calcrom.pl b/calcrom.pl
new file mode 100644
index 00000000..83051c67
--- /dev/null
+++ b/calcrom.pl
@@ -0,0 +1,152 @@
+#!/usr/bin/perl
+
+# Usage:
+#   calcrom.pl <mapfile> [--verbose]
+#
+#   mapfile: path to .map file output by LD
+#   verbose: set to get more detailed output
+
+use IPC::Cmd qw[ run ];
+use Getopt::Long;
+
+my $verbose = "";
+
+GetOptions("verbose" => \$verbose);
+(@ARGV == 1)
+    or die "ERROR: no map file specified.\n";
+open(my $file, $ARGV[0])
+    or die "ERROR: could not open file '$ARGV[0]'.\n";
+
+my $src = 0;
+my $asm = 0;
+my $srcdata = 0;
+my $data = 0;
+my @pairs = ();
+while (my $line = <$file>)
+{
+    if ($line =~ /^ \.(\w+)\s+0x[0-9a-f]+\s+(0x[0-9a-f]+) (\w+)\/(.+)\.o/)
+    {
+        my $section = $1;
+        my $size = hex($2);
+        my $dir = $3;
+        my $basename = $4;
+        if ($size & 3)
+        {
+            $size += 4 - ($size % 3);
+        }
+
+        if ($section =~ /text/)
+        {
+            if ($dir eq 'src')
+            {
+                $src += $size;
+            }
+            elsif ($dir eq 'asm')
+            {
+                if (!($basename =~ /(crt0|libagbsyscall|libgcnmultiboot|m4a_1)/))
+                {
+                    push @pairs, [$basename, $size];
+                }
+                $asm += $size;
+            }
+        }
+        elsif ($section =~ /rodata/)
+        {
+            if ($dir eq 'src')
+            {
+                $srcdata += $size;
+            }
+            elsif ($dir eq 'data')
+            {
+                $data += $size;
+            }
+        }
+    }
+}
+
+my @sorted = sort { $a->[1] <=> $b->[1] } @pairs;
+
+# Note that the grep filters out all branch labels. It also requires a minimum
+# line length of 5, to filter out a ton of generated symbols (like AcCn). No
+# settings to nm seem to remove these symbols. Finally, nm prints out a separate
+# entry for whenever a name appears in a file, not just where it's defined. uniq
+# removes all the duplicate entries.
+#
+#
+# You'd expect this to take a while, because of uniq. It runs in under a second,
+# though. Uniq is pretty fast!
+my $base_cmd = "nm zeldatmc.elf | awk '{print \$3}' | grep '^[^_].\\{4\\}' | uniq";
+
+# This looks for Unknown_, Unknown_, or sub_, followed by just numbers. Note that
+# it matches even if stuff precedes the unknown, like sUnknown/gUnknown.
+my $undoc_cmd = "grep '[Uu]nk_[0-9a-fA-F]*\\|sub_[0-9a-fA-F]*'";
+
+my $count_cmd = "wc -l";
+
+# It sucks that we have to run this three times, but I can't figure out how to get
+# stdin working for subcommands in perl while still having a timeout. It's decently
+# fast anyway.
+my $total_syms_as_string;
+(run (
+    command => "$base_cmd | $count_cmd",
+    buffer => \$total_syms_as_string,
+    timeout => 60
+))
+    or die "ERROR: Error while getting all symbols: $?";
+
+my $undocumented_as_string;
+(run (
+    command => "$base_cmd | $undoc_cmd | $count_cmd",
+    buffer => \$undocumented_as_string,
+    timeout => 60
+))
+    or die "ERROR: Error while filtering for undocumented symbols: $?";
+
+# Performing addition on a string converts it to a number. Any string that fails
+# to convert to a number becomes 0. So if our converted number is 0, but our string
+# is nonzero, then the conversion was an error.
+my $undocumented = $undocumented_as_string + 0;
+(($undocumented != 0) and ($undocumented_as_string ne "0"))
+    or die "ERROR: Cannot convert string to num: '$undocumented_as_string'";
+
+my $total_syms = $total_syms_as_string + 0;
+(($total_syms != 0) and ($total_syms_as_string ne "0"))
+    or die "ERROR: Cannot convert string to num: '$total_syms_as_string'";
+
+($total_syms != 0)
+    or die "ERROR: No symbols found.";
+
+my $total = $src + $asm;
+my $srcPct = sprintf("%.4f", 100 * $src / $total);
+my $asmPct = sprintf("%.4f", 100 * $asm / $total);
+
+my $documented = $total_syms - ($undocumented);
+my $docPct = sprintf("%.4f", 100 * $documented / $total_syms);
+my $undocPct = sprintf("%.4f", 100 * $undocumented / $total_syms);
+
+print "$total total bytes of code\n";
+print "$src bytes of code in src ($srcPct%)\n";
+print "$asm bytes of code in asm ($asmPct%)\n";
+print "\n";
+
+if ($verbose != 0)
+{
+    print "BREAKDOWN\n";
+    foreach my $item (@sorted)
+    {
+        print "    $item->[1] bytes in asm/$item->[0].s\n"
+    }
+    print "\n";
+}
+
+print "$total_syms total symbols\n";
+print "$documented symbols documented ($docPct%)\n";
+print "$undocumented symbols undocumented ($undocPct%)\n";
+
+print "\n";
+my $dataTotal = $srcdata + $data;
+my $srcDataPct = sprintf("%.4f", 100 * $srcdata / $dataTotal);
+my $dataPct = sprintf("%.4f", 100 * $data / $dataTotal);
+print "$dataTotal total bytes of data\n";
+print "$srcdata bytes of data in src ($srcDataPct%)\n";
+print "$data bytes of data in data ($dataPct%)\n";
diff --git a/tools/preproc/charmap.cpp b/tools/preproc/charmap.cpp
index e4a8999b..5625a852 100644
--- a/tools/preproc/charmap.cpp
+++ b/tools/preproc/charmap.cpp
@@ -67,7 +67,12 @@ private:
 
 CharmapReader::CharmapReader(std::string filename) : m_filename(filename)
 {
-    if (filename == "") { m_buffer = new char[1] {}; return; }
+    if (filename == "")
+    {
+        m_size = 0;
+        m_buffer = new char[1] {};
+        return;
+    }
 
     FILE *fp = std::fopen(filename.c_str(), "rb");