q/src/build/core/CompileCall.go

40 lines
1.2 KiB
Go

package core
import (
"git.akyoto.dev/cli/q/src/build/cpu"
"git.akyoto.dev/cli/q/src/build/expression"
)
// CompileCall 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) CompileCall(expr *expression.Expression) error {
_, err := f.EvaluateCall(expr)
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
}
// ExpressionsToRegisters moves multiple expressions into the specified registers.
func (f *Function) ExpressionsToRegisters(expressions []*expression.Expression, registers []cpu.Register) error {
for i := len(registers) - 1; i >= 0; i-- {
f.SaveRegister(registers[i])
err := f.EvaluateTo(expressions[i], registers[i])
if err != nil {
return err
}
}
return nil
}