1 files changed, 70 insertions, 0 deletions
diff --git a/01-system-clock/genmake.pl b/01-system-clock/genmake.pl
new file mode 100755
index 0000000..341db3d
--- /dev/null
+++ b/01-system-clock/genmake.pl
@@ -0,0 +1,70 @@
+#!/usr/bin/perl
+
+# This script is designed to introspect C files and generate a makefile to use.
+
+sub header_deps {
+  my $file = @_[0];
+  my @headers;
+
+  if (open(my $fh, '<:encoding(UTF-8)', $file)) {
+    print STDERR "\x1b[35m[Trace] - Reading file $file\x1b[00m\n";
+    push(@headers, $file);
+
+    while (<$fh>) {
+      /#include\s+"(.*)"\s*$/ && push(@headers, header_deps("include/$1"));
+    }
+  }
+
+  return @headers;
+}
+
+my @files = glob('src/*.c');
+my @obj_files;
+
+open(my $fh, '<:encoding(UTF-8)', "Makefile.preamble")
+    or die "Missing Makefile.preamble";
+
+while (<$fh>) {
+  print "$_";
+}
+
+# Emit a rule that will rerun genmake if the c files do not match.
+my $idempotency_cmd =
+    "ls src/*.c include/*.h| sha1sum | awk '{print \$1}'";
+
+my $idempotency_cmd_make =
+    "ls src/*.c include/*.h | sha1sum | awk '{print \$\$1}'";
+
+print "IDEMPOTENCY_HASH=" . `$idempotency_cmd` . "\n";
+
+my $arch_obs_dir = "_\$(PREFIX)_obs";
+print "CHEAT_PRE_MAKE := \$(shell mkdir -p $arch_obs_dir)\n";
+
+foreach $file (@files) {
+  my $c_file = $file;
+  (my $file_no_ext = $file) =~ s/src\/(.*)\.c$/\1/g;
+
+  my $obj_file = "$arch_obs_dir/${file_no_ext}.o";
+  my $s_file = "${file_no_ext}.s";
+
+  push(@obj_files, $obj_file);
+  my @deps = header_deps($c_file);
+
+  my $deps_as_join = join(" ", @deps);
+
+  # Emit the rule to make the object file.
+  print "$obj_file: $deps_as_join\n\t";
+  print '$(CC) -c ' . $c_file . ' -o ' . $obj_file . ' $(CFLAGS)' . "\n\n";
+
+  # Emit the rule to make the assembly file.
+  print "$s_file: $deps_as_join\n\t";
+  print '$(CC) -S ' . $c_file . ' -o ' . $s_file . ' $(CFLAGS)' . "\n\n";
+}
+
+my $obj_files_deps = join(' ', @obj_files);
+print "FORCE:\n\t\n\n";
+print "$arch_obs_dir/main.elf: FORCE $obj_files_deps linker/linker_script.ld\n\t";
+print "([ \"\$\$($idempotency_cmd_make)\" != \"\$(IDEMPOTENCY_HASH)\" ] "
+        . "&& ./genmake.pl > Makefile && make main.elf ) "
+        . "|| "
+        . "\$(LD) -o $arch_obs_dir/main.elf \$(LD_FLAGS) $obj_files_deps\n\n";