From 1e26c9cac07052da54b58dffc1ce3eab5670ee5a Mon Sep 17 00:00:00 2001
From: Erica Marigold <hi@devcomp.xyz>
Date: Thu, 18 Jul 2024 22:04:27 +0530
Subject: [PATCH] fix: just pass C pointers in NewState & PushCClosureK

---
 internal/clua.c | 15 ++++++++-------
 internal/clua.h |  3 +--
 internal/lua.go | 29 +++++++++++++++++++----------
 main.go         |  8 ++++++--
 4 files changed, 34 insertions(+), 21 deletions(-)

diff --git a/internal/clua.c b/internal/clua.c
index 1ad986f..479f1a5 100644
--- a/internal/clua.c
+++ b/internal/clua.c
@@ -2,14 +2,15 @@
 #include <lua.h>
 #include <_cgo_export.h>
 
-void* clua_alloc(void* ud, void *ptr, size_t osize, size_t nsize)
-{
-	return (void*) go_allocf((GoUintptr) ud,(GoUintptr) ptr, osize, nsize);
-}
+// void* clua_alloc(void* ud, void *ptr, size_t osize, size_t nsize)
+// {
+// 	return (void*) go_allocf((GoUintptr) ud,(GoUintptr) ptr, osize, nsize);
+// }
 
-lua_State* clua_newstate(void* goallocf)
+
+lua_State* clua_newstate(void* f, void* ud)
 {
-	return lua_newstate(&clua_alloc, goallocf);
+	return lua_newstate((lua_Alloc)f, ud);
 }
 
 l_noret cluaL_errorL(lua_State* L, char* msg)
@@ -18,5 +19,5 @@ l_noret cluaL_errorL(lua_State* L, char* msg)
 }
 
 void clua_pushcclosurek(lua_State* L, void* f, char* debugname, int nup, void* cont) {
-	return lua_pushcclosurek(L, f, debugname, nup, cont);
+	return lua_pushcclosurek(L, (lua_CFunction)f, debugname, nup, (lua_Continuation)cont);
 }
\ No newline at end of file
diff --git a/internal/clua.h b/internal/clua.h
index 5693d3c..997dbda 100644
--- a/internal/clua.h
+++ b/internal/clua.h
@@ -1,7 +1,6 @@
 #include <stdlib.h>
 #include <lua.h>
 
-void* clua_alloc(void* ud, void *ptr, size_t osize, size_t nsize);
-lua_State* clua_newstate(void* goallocf);
+lua_State* clua_newstate(void* f, void* ud);
 l_noret cluaL_errorL(lua_State* L, char* msg);
 void clua_pushcclosurek(lua_State* L, void* f, char* debugname, int nup, void* cont);
\ No newline at end of file
diff --git a/internal/lua.go b/internal/lua.go
index 2c80c8d..5801fbf 100644
--- a/internal/lua.go
+++ b/internal/lua.go
@@ -22,14 +22,13 @@ type LuaContinuation func(L *LuaState, status int32) int32
 type LuaUDestructor = func(*C.void)
 type LuaDestructor = func(L *LuaState, _ unsafe.Pointer)
 
-// type LuaAlloc = func(ud, ptr *C.void, osize, nsize C.size_t) *C.void
-type LuaAlloc = func(ptr unsafe.Pointer, osize, nsize uint64) unsafe.Pointer
+type LuaAlloc = func(ud, ptr unsafe.Pointer, osize, nsize C.size_t) *C.void
 
-//export go_allocf
-func go_allocf(fp uintptr, ptr uintptr, osize uint64, nsize uint64) uintptr {
-	p := ((*((*LuaAlloc)(unsafe.Pointer(fp))))(unsafe.Pointer(ptr), osize, nsize))
-	return uintptr(p)
-}
+// TODO: Figure out when to C.malloc, and when to pass Go ptr
+// Answer: If C frees some memory, then it's to be C.malloc'd, else pass go ptr
+// Basically, some lua functions will manage memory themselves, and in that case
+// we give them a C pointer - else we manage it ourselves. Technically you can give
+// everything a C pointer, but you don't need to!
 
 //
 // ==================
@@ -37,8 +36,14 @@ func go_allocf(fp uintptr, ptr uintptr, osize uint64, nsize uint64) uintptr {
 // ==================
 //
 
-func NewState(ud unsafe.Pointer) *LuaState {
-	return C.clua_newstate(unsafe.Pointer(ud))
+func NewState(f LuaAlloc, ud unsafe.Pointer) *LuaState {
+	cf := C.malloc(C.size_t(unsafe.Sizeof(f)))
+	*(*LuaAlloc)(cf) = f
+
+	cud := C.malloc(C.size_t(unsafe.Sizeof(ud)))
+	cud = ud
+
+	return C.clua_newstate(cf, cud)
 }
 
 func LuaClose(L *LuaState) {
@@ -299,10 +304,14 @@ func PushCClosureK(L *LuaState, f LuaCFunction, debugname string, nup int32, con
 	if cont == nil {
 		ccont = C.NULL
 	} else {
+		ccont = C.malloc(C.size_t(unsafe.Sizeof(cont)))
 		ccont = unsafe.Pointer(&cont)
 	}
 
-	C.clua_pushcclosurek(L, unsafe.Pointer(&f), cdebugname, C.int(nup), ccont)
+	cf := C.malloc(C.size_t(unsafe.Sizeof(f)))
+	*(*LuaCFunction)(cf) = f
+
+	C.clua_pushcclosurek(L, cf, cdebugname, C.int(nup), ccont)
 }
 
 // TODO: Rest of it
diff --git a/main.go b/main.go
index f34d754..1204f31 100644
--- a/main.go
+++ b/main.go
@@ -4,10 +4,14 @@ import lualib "github.com/CompeyDev/lei/internal"
 
 func main() {
 	lua := lualib.LNewState()
+	println("Lua VM Address: ", lua)
+
 	lualib.PushCClosureK(lua, func(L *lualib.LuaState) int32 {
-		println("hi from closure? ")
+		println("hi from closure?")
 		return 0
 	}, "test", 0, nil)
 
-	println(lua)
+	if !lualib.IsCFunction(lua, 1) {
+		panic("CFunction was not correctly pushed onto stack")
+	}
 }