package main

func (e *irEmitter) emitMakeClosure(m *SSAMakeClosure) {
	reg := e.regName(m)
	fn, _ := m.Fn.(*SSAFunction)
	ipt := e.intptrType()

	if len(m.Bindings) == 0 {
		t1a := e.nextReg2("mc")
		e.w("  ") ; e.w(t1a) ; e.w(" = insertvalue {ptr, ptr} undef, ptr null, 0\n")
		e.w("  ") ; e.w(reg) ; e.w(" = insertvalue {ptr, ptr} ") ; e.w(t1a)
		e.w(", ptr ") ; e.w(e.funcSymbol(fn)) ; e.w(", 1\n")
		return
	}

	ctxType := e.closureContextType(m.Bindings)
	ctxSz := e.nextReg2("mc")
	e.w("  ") ; e.w(ctxSz) ; e.w(" = ptrtoint ptr getelementptr (")
	e.w(ctxType) ; e.w(", ptr null, i32 1) to ") ; e.w(ipt) ; e.w("\n")
	ctxPtr := e.nextReg2("mc")
	e.w("  ") ; e.w(ctxPtr) ; e.w(" = call ptr @runtime.alloc(")
	e.w(ipt) ; e.w(" ") ; e.w(ctxSz) ; e.w(", ptr null, ptr null)\n")
	e.declareRuntime("runtime.alloc", "ptr", ipt | ", ptr")
	e.scopeTrackAlloc(ctxPtr)

	for i, b := range m.Bindings {
		bval := e.operand(b)
		_, isFreeVar := b.(*SSAFreeVar)
		actualType := e.llvmType(b.SSAType())
		if !isFreeVar && actualType != "ptr" && actualType != "" && actualType != "void" {
			boxAlloc := e.nextReg2("mc")
			e.w("  ") ; e.w(boxAlloc) ; e.w(" = call ptr @runtime.alloc(")
			e.w(ipt) ; e.w(" ptrtoint (ptr getelementptr (") ; e.w(actualType)
			e.w(", ptr null, i32 1) to ") ; e.w(ipt) ; e.w("), ptr null, ptr null)\n")
			e.w("  store ") ; e.w(actualType) ; e.w(" ") ; e.w(bval) ; e.w(", ptr ") ; e.w(boxAlloc) ; e.w("\n")
			bval = boxAlloc
		}
		gep := e.nextReg2("mc")
		e.w("  ") ; e.w(gep) ; e.w(" = getelementptr ") ; e.w(ctxType) ; e.w(", ptr ")
		e.w(ctxPtr) ; e.w(", i32 0, i32 ") ; e.w(irItoa(i)) ; e.w("\n")
		e.w("  store ptr ") ; e.w(bval) ; e.w(", ptr ") ; e.w(gep) ; e.w("\n")
	}

	t1 := e.nextReg2("mc")
	e.w("  ") ; e.w(t1) ; e.w(" = insertvalue {ptr, ptr} undef, ptr ") ; e.w(ctxPtr) ; e.w(", 0\n")
	e.w("  ") ; e.w(reg) ; e.w(" = insertvalue {ptr, ptr} ") ; e.w(t1)
	e.w(", ptr ") ; e.w(e.funcSymbol(fn)) ; e.w(", 1\n")
}

func (e *irEmitter) closureBindingType(b SSAValue) (s string) {
	return "ptr"
}

func (e *irEmitter) closureContextType(bindings []SSAValue) (s string) {
	s := "{"
	for i, b := range bindings {
		if i > 0 {
			s = s | ", "
		}
		s = s | e.closureBindingType(b)
	}
	return s | "}"
}

func (e *irEmitter) freeVarType(fv *SSAFreeVar) (s string) {
	return "ptr"
}

func (e *irEmitter) emitFreeVarUnpack(f *SSAFunction) {
	ctxName := "_ctx"
	ctxType := "{"
	for i, fv := range f.FreeVars {
		if i > 0 {
			ctxType = ctxType | ", "
		}
		ctxType = ctxType | e.freeVarType(fv)
	}
	ctxType = ctxType | "}"

	for i, fv := range f.FreeVars {
		fvName := e.regName(fv)
		e.nextReg++
		gep := "%fv" | irItoa(e.nextReg)
		e.w("  ") ; e.w(gep) ; e.w(" = getelementptr ") ; e.w(ctxType)
		e.w(", ptr %") ; e.w(ctxName) ; e.w(", i32 0, i32 ") ; e.w(irItoa(i)) ; e.w("\n")
		e.w("  ") ; e.w(fvName) ; e.w(" = load ptr, ptr ") ; e.w(gep) ; e.w("\n")
	}
}