require 'formula'

class Lua < Formula
  # 5.2 is not fully backwards compatible, and breaks e.g. luarocks.
  # It is available in Homebrew-versions for the time being.
  homepage 'http://www.lua.org/'
  url 'http://www.lua.org/ftp/lua-5.1.5.tar.gz'
  sha1 'b3882111ad02ecc6b972f8c1241647905cb2e3fc'

  fails_with :llvm do
    build 2326
    cause "Lua itself compiles with LLVM, but may fail when other software tries to link."
  end

  option :universal
  option 'completion', 'Enables advanced readline support'

  # Be sure to build a dylib, or else runtime modules will pull in another static copy of liblua = crashy
  # See: https://github.com/mxcl/homebrew/pull/5043
  def patches
    p = [DATA]
    # completion provided by advanced readline power patch from
    # http://lua-users.org/wiki/LuaPowerPatches
    if build.include? 'completion'
      p << 'http://luajit.org/patches/lua-5.1.4-advanced_readline.patch'
    end
    p
  end

  def install
    ENV.universal_binary if build.universal?

    # Use our CC/CFLAGS to compile.
    inreplace 'src/Makefile' do |s|
      s.remove_make_var! 'CC'
      s.change_make_var! 'CFLAGS', "#{ENV.cflags} $(MYCFLAGS)"
      s.change_make_var! 'MYLDFLAGS', ENV.ldflags
      s.sub! 'MYCFLAGS_VAL', "-fno-common -DLUA_USE_LINUX"
    end

    # Fix path in the config header
    inreplace 'src/luaconf.h', '/usr/local', HOMEBREW_PREFIX

    # Fix paths in the .pc
    inreplace 'etc/lua.pc' do |s|
      s.gsub! "prefix= /usr/local", "prefix=#{HOMEBREW_PREFIX}"
      s.gsub! "INSTALL_MAN= ${prefix}/man/man1", "INSTALL_MAN= ${prefix}/share/man/man1"
    end

    # this ensures that this symlinking for lua starts at lib/lua/5.1 and not
    # below that, thus making luarocks work
    (HOMEBREW_PREFIX/"lib/lua"/version.to_s.split('.')[0..1].join('.')).mkpath

    system "make", "macosx", "INSTALL_TOP=#{prefix}", "INSTALL_MAN=#{man1}"
    system "make", "install", "INSTALL_TOP=#{prefix}", "INSTALL_MAN=#{man1}"

    (lib+"pkgconfig").install 'etc/lua.pc'
  end
end

__END__
diff --git a/Makefile b/Makefile
index 209a132..9387b09 100644
--- a/Makefile
+++ b/Makefile
@@ -43,7 +43,7 @@ PLATS= aix ansi bsd freebsd generic linux macosx mingw posix solaris
 # What to install.
 TO_BIN= lua luac
 TO_INC= lua.h luaconf.h lualib.h lauxlib.h ../etc/lua.hpp
-TO_LIB= liblua.a
+TO_LIB= liblua.5.1.5.dylib
 TO_MAN= lua.1 luac.1
 
 # Lua version and release.
@@ -64,6 +64,8 @@ install: dummy
 	cd src && $(INSTALL_DATA) $(TO_INC) $(INSTALL_INC)
 	cd src && $(INSTALL_DATA) $(TO_LIB) $(INSTALL_LIB)
 	cd doc && $(INSTALL_DATA) $(TO_MAN) $(INSTALL_MAN)
+	ln -s -f liblua.5.1.5.dylib $(INSTALL_LIB)/liblua.5.1.dylib
+	ln -s -f liblua.5.1.dylib $(INSTALL_LIB)/liblua.dylib
 
 ranlib:
 	cd src && cd $(INSTALL_LIB) && $(RANLIB) $(TO_LIB)
diff --git a/src/Makefile b/src/Makefile
index e0d4c9f..4477d7b 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -22,7 +22,7 @@ MYLIBS=
 
 PLATS= aix ansi bsd freebsd generic linux macosx mingw posix solaris
 
-LUA_A=	liblua.a
+LUA_A=	liblua.5.1.5.dylib
 CORE_O=	lapi.o lcode.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o lmem.o \
 	lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o ltm.o  \
 	lundump.o lvm.o lzio.o
@@ -48,11 +48,13 @@ o:	$(ALL_O)
 a:	$(ALL_A)
 
 $(LUA_A): $(CORE_O) $(LIB_O)
-	$(AR) $@ $(CORE_O) $(LIB_O)	# DLL needs all object files
-	$(RANLIB) $@
+	$(CC) -dynamiclib -install_name HOMEBREW_PREFIX/lib/liblua.5.1.dylib \
+		-compatibility_version 5.1 -current_version 5.1.5 \
+		-o liblua.5.1.5.dylib $^
 
 $(LUA_T): $(LUA_O) $(LUA_A)
-	$(CC) -o $@ $(MYLDFLAGS) $(LUA_O) $(LUA_A) $(LIBS)
+	$(CC) -fno-common $(MYLDFLAGS) \
+		-o $@ $(LUA_O) $(LUA_A) -L. -llua.5.1.5 $(LIBS)
 
 $(LUAC_T): $(LUAC_O) $(LUA_A)
 	$(CC) -o $@ $(MYLDFLAGS) $(LUAC_O) $(LUA_A) $(LIBS)
@@ -99,7 +101,7 @@ linux:
 	$(MAKE) all MYCFLAGS=-DLUA_USE_LINUX MYLIBS="-Wl,-E -ldl -lreadline -lhistory -lncurses"
 
 macosx:
-	$(MAKE) all MYCFLAGS=-DLUA_USE_LINUX MYLIBS="-lreadline"
+	$(MAKE) all MYCFLAGS="MYCFLAGS_VAL" MYLIBS="-lreadline"
 # use this on Mac OS X 10.3-
 #	$(MAKE) all MYCFLAGS=-DLUA_USE_MACOSX