q/src/core/EvaluateDot.go

83 lines
1.8 KiB
Go

package core
import (
"fmt"
"math"
"git.urbach.dev/cli/q/src/asm"
"git.urbach.dev/cli/q/src/errors"
"git.urbach.dev/cli/q/src/eval"
"git.urbach.dev/cli/q/src/expression"
"git.urbach.dev/cli/q/src/types"
)
// EvaluateDot evaluates an access with the dot operator.
func (f *Function) EvaluateDot(expr *expression.Expression) (eval.Value, error) {
left := expr.Children[0]
right := expr.Children[1]
leftText := left.Token.Text(f.File.Bytes)
rightText := right.Token.Text(f.File.Bytes)
variable := f.VariableByName(leftText)
if variable != nil {
f.UseVariable(variable)
pointer := variable.Value.Typ.(*types.Pointer)
structure := pointer.To.(*types.Struct)
field := structure.FieldByName(rightText)
if field == nil {
return nil, errors.New(&errors.UnknownStructField{StructName: structure.Name(), FieldName: rightText}, f.File, right.Token.Position)
}
value := &eval.Memory{
Typ: field.Type,
Memory: asm.Memory{
Base: variable.Value.Register,
Offset: int8(field.Offset),
OffsetRegister: math.MaxUint8,
Length: byte(field.Type.Size()),
},
}
return value, nil
}
constant, isConst := f.All.Constants[f.Package+"."+leftText+"."+rightText]
if isConst {
number, err := ToNumber(constant.Token, constant.File)
if err != nil {
return nil, err
}
value := &eval.Number{
Typ: types.AnyInt,
Number: number,
}
return value, nil
}
if leftText != "main" {
imp, exists := f.File.Imports[leftText]
if exists {
imp.Used = true
} else {
_, exists := f.All.Extern[leftText]
if !exists {
return nil, errors.New(&errors.UnknownPackage{Name: leftText}, f.File, left.Token.Position)
}
}
}
value := &eval.Label{
Typ: types.AnyPointer,
Label: fmt.Sprintf("%s.%s", leftText, rightText),
}
return value, nil
}