From 98c1b2d599c8acc363dd41ca2ec983ed7f8597d6 Mon Sep 17 00:00:00 2001
From: jyelon <jyelon@gmail.com>
Date: Tue, 21 Feb 2023 15:28:45 -0500
Subject: [PATCH] Convert to a true DLL engine

---
 luprex/.gitignore               |  6 ++-
 luprex/Makefile                 | 67 ++++++++++++++++++++++++++-------
 luprex/cpp/core/luastack.hpp    |  2 -
 luprex/cpp/drv/driver-linux.cpp | 12 ++----
 4 files changed, 62 insertions(+), 25 deletions(-)

diff --git a/luprex/.gitignore b/luprex/.gitignore
index 872781f8..273f56b6 100644
--- a/luprex/.gitignore
+++ b/luprex/.gitignore
@@ -1,5 +1,8 @@
+a.out
 gprof.out
 gmon.out
+luprex
+
 *~
 \#*#
 .#*
@@ -7,8 +10,9 @@ gmon.out
 *.o
 *.dll
 *.exe
+*.so
 *.a
-main
+
 obj/**
 .vscode/**
 ext/eris-master/src/lua
diff --git a/luprex/Makefile b/luprex/Makefile
index c70b6214..85715670 100644
--- a/luprex/Makefile
+++ b/luprex/Makefile
@@ -1,23 +1,42 @@
+#######################################################################
+##
+## Auto detect Operating System
+##
+#######################################################################
 
 ifneq "" "$(findstring -linux-,$(MAKE_HOST))"
+
   OS=linux
-  EXE=main
-  LIBS=-L./ext/openssl-linux -lssl -lcrypto -ldl
+  EXE=luprex
+  DLL=luprex.so
+  LIBS=-L./ext/openssl-mingw -lssl -lcrypto -ldl
   LUAFLAGS=-DLUA_USE_APICHECK -DLUA_USE_POSIX
   OPT=-g -O0
+
 else ifneq "" "$(findstring cmd.exe,$(COMSPEC))"
+
   OS=mingw
-  EXE=main.exe
+  EXE=luprex.exe
+  DLL=luprex.dll
   LIBS=-L./ext/openssl-mingw -lssl -lcrypto -lws2_32 -lcrypt32 -lcryptui
   LUAFLAGS=-DLUA_USE_APICHECK -DLUA_COMPAT_ALL
   OPT=-g -O0
+
 else
+
   $(error Cannot figure out whether to build the linux or mingw version)
+
 endif
-
-
 $(info Building for $(OS)...)
 
+
+
+#######################################################################
+##
+## List of all OBJ files
+##
+#######################################################################
+
 OBJ_ERIS=\
 	obj/eris/lapi.o \
 	obj/eris/lcode.o \
@@ -91,25 +110,47 @@ OBJ_CORE=\
 OBJ_DRV=\
 	obj/drv/drvutil.o\
 	obj/drv/sslutil.o\
-	obj/drv/driver-$(OS).o
+	obj/drv/driver-$(OS).o\
 
 
 
-$(EXE): $(OBJ_ERIS) $(OBJ_CORE) $(OBJ_DRV)
-	g++ $(OPT) -std=c++17 -export-dynamic -Wall -o $@ $(OBJ_ERIS) $(OBJ_CORE) $(OBJ_DRV) $(LIBS)
+#######################################################################
+##
+## Make rules
+##
+#######################################################################
+
+GPP=g++ -Wall -fvisibility=hidden $(OPT) -std=c++17 -MMD
+
+all: $(EXE) $(DLL)
+
+$(EXE): $(OBJ_DRV)
+	$(GPP) -o $@ $(OBJ_DRV) -L./ext/openssl-linux -lssl -lcrypto -ldl
+
+$(DLL): $(OBJ_ERIS) $(OBJ_CORE)
+	$(GPP) -export-dynamic -Wl,--no-allow-shlib-undefined -Wl,-z,defs -shared -o $@ $^
 
 obj/eris/%.o: ext/eris-master/src/%.c
-	gcc $(OPT) -Wall -fvisibility=hidden $(LUAFLAGS) -c -MMD $< -o $@
+	$(GPP) -fPIC $(LUAFLAGS) -o $@ -c $<
 
 obj/core/%.o: cpp/core/%.cpp
-	g++ $(OPT) -Wall -fvisibility=hidden -std=c++17 -I./ext/eris-master/src -I./cpp/wrap -I./cpp/core -c -MMD $< -o $@
+	$(GPP) -fPIC -I./ext/eris-master/src -I./cpp/wrap -I./cpp/core -o $@ -c $<
 
 obj/drv/%.o: cpp/drv/%.cpp
-	g++ $(OPT) -Wall -fvisibility=hidden -std=c++17 -I./ext -I./src/drv -c -MMD $< -o $@
+	$(GPP) -I./ext -I./src/drv -o $@ -c $<
 
 clean:
-	rm -f main.exe main obj/core/*.* obj/drv/*.* obj/eris/*.*
+	rm -f luprex luprex.exe luprex.so luprex.dll obj/core/*.* obj/drv/*.* obj/eris/*.*
+
+
+
+#######################################################################
+##
+## Automatically generated Make Dependencies
+##
+#######################################################################
 
 -include $(OBJ_ERIS:%.o=%.d)
--include $(OBJ_ERIS:%.o=%.d)
+-include $(OBJ_CORE:%.o=%.d)
+-include $(OBJ_DRV:%.o=%.d)
 
diff --git a/luprex/cpp/core/luastack.hpp b/luprex/cpp/core/luastack.hpp
index 321d5c24..6600e14e 100644
--- a/luprex/cpp/core/luastack.hpp
+++ b/luprex/cpp/core/luastack.hpp
@@ -158,12 +158,10 @@
 #include "wrap-set.hpp"
 #include <cstring>
 
-extern "C" {
 #include "lua.h"
 #include "lauxlib.h"
 #include "lualib.h"
 #include "eris.h"
-}
 
 class LuaSlot : public eng::nevernew {
 protected:
diff --git a/luprex/cpp/drv/driver-linux.cpp b/luprex/cpp/drv/driver-linux.cpp
index 559e22bf..55663724 100644
--- a/luprex/cpp/drv/driver-linux.cpp
+++ b/luprex/cpp/drv/driver-linux.cpp
@@ -217,17 +217,11 @@ static int console_read(char *bytes, int nbytes) {
     return read(0, bytes, nbytes);
 }
 
-// Load the DLL if it's not already loaded. Stores
-// the handle in a global variable.
-static void load_engine_dll() {
-    // Not actually implemented yet.  Currently, the engine
-    // is linked right into the executable.
-}
-
 static void call_init_engine_wrapper(EngineWrapper *w) {
-    load_engine_dll();
     using InitFn = void (*)(EngineWrapper *);
-    InitFn initfn = (InitFn)dlsym(RTLD_DEFAULT, "init_engine_wrapper");
+    void *dll_handle = dlopen("./luprex.so", RTLD_NOW | RTLD_LOCAL);
+    assert(dll_handle != nullptr);
+    InitFn initfn = (InitFn)dlsym(dll_handle, "init_engine_wrapper");
     assert(initfn != nullptr);
     initfn(w);
 }