package build

import (
	"git.akyoto.dev/cli/q/src/build/config"
	"git.akyoto.dev/cli/q/src/build/expression"
)

// CompileFunctionCall executes a function call.
// All call registers must hold the correct parameter values before the function invocation.
// Registers that are in use must be saved if they are modified by the function.
// After the function call, they must be restored in reverse order.
func (f *Function) CompileFunctionCall(expr *expression.Expression) error {
	funcName := expr.Children[0].Token.Text()

	if funcName == "syscall" {
		return f.CompileSyscall(expr)
	}

	function := f.functions[funcName]

	if function != f {
		function.Wait()
	}

	parameters := expr.Children[1:]
	registers := f.cpu.Call[:len(parameters)]

	err := f.ExpressionsToRegisters(parameters, registers)

	if config.Verbose {
		f.Logf("call: %s", funcName)
	}

	f.assembler.Call(funcName)
	f.sideEffects += function.sideEffects
	return err
}

// CompileSyscall executes a syscall.
func (f *Function) CompileSyscall(expr *expression.Expression) error {
	parameters := expr.Children[1:]
	registers := f.cpu.Syscall[:len(parameters)]
	err := f.ExpressionsToRegisters(parameters, registers)
	f.assembler.Syscall()
	f.sideEffects++
	return err
}