func assign(b *builder, dest *ref, src *ref, op *lex8.Token) bool {
ndest := dest.Len()
nsrc := src.Len()
if ndest != nsrc {
b.Errorf(op.Pos, "cannot assign %s to %s",
nsrc, ndest,
)
return false
}
for i, destType := range dest.typ {
if !dest.ir[i].Addressable() {
b.Errorf(op.Pos, "assigning to non-addressable")
return false
}
srcType := src.typ[i]
if !types.CanAssign(destType, srcType) {
b.Errorf(op.Pos, "cannot assign %s to %s", src, dest)
return false
}
}
// perform the assignment
for i, dest := range dest.ir {
b.b.Assign(dest, src.ir[i])
}
return true
}
func buildCallExpr(b *builder, expr *ast.CallExpr) *ref {
f := b.buildExpr(expr.Func)
if f == nil {
return nil
}
pos := ast.ExprPos(expr.Func)
if !f.IsSingle() {
b.Errorf(pos, "expression list is not callable")
return nil
}
funcType, ok := f.Type().(*types.Func) // the func sig in the builder
if !ok {
// not a function
b.Errorf(pos, "function call on non-callable")
return nil
}
args := buildExprList(b, expr.Args)
if args == nil {
return nil
}
if args.Len() != len(funcType.Args) {
b.Errorf(ast.ExprPos(expr), "argument expects (%s), got (%s)",
fmt8.Join(funcType.Args, ","), fmt8.Join(args.typ, ","),
)
return nil
}
// type check on parameters
for i, argType := range args.typ {
expect := funcType.Args[i].T
if !types.CanAssign(expect, argType) {
pos := ast.ExprPos(expr.Args.Exprs[i])
b.Errorf(pos, "argument %d expects %s, got %s",
i+1, expect, argType,
)
}
}
ret := new(ref)
ret.typ = funcType.RetTypes
for _, t := range funcType.RetTypes {
ret.ir = append(ret.ir, b.f.NewTemp(t.Size(), types.IsByte(t)))
}
// call the func in IR
b.b.Call(ret.ir, f.IR(), funcType.Sig, args.ir...)
return ret
}
func buildReturnStmt(b *builder, stmt *ast.ReturnStmt) {
pos := stmt.Kw.Pos
if stmt.Exprs == nil {
println(b.fretNamed)
if b.fretRef == nil || b.fretNamed {
buildFuncExit(b)
} else {
b.Errorf(pos, "expects return %s", b.fretRef)
}
} else {
if b.fretRef == nil {
b.Errorf(pos, "function expects no return value")
return
}
ref := buildExprList(b, stmt.Exprs)
if ref == nil {
return
}
nret := b.fretRef.Len()
nsrc := ref.Len()
if nret != nsrc {
b.Errorf(pos, "expects (%s), returning (%s)", b.fretRef, ref)
return
}
for i, t := range b.fretRef.typ {
if !b.fretRef.ir[i].Addressable() {
panic("bug")
}
srcType := ref.typ[i]
if !types.CanAssign(t, srcType) {
b.Errorf(pos, "expect (%s), returning (%s)", b.fretRef, ref)
return
}
}
for i, dest := range b.fretRef.ir {
b.b.Assign(dest, ref.ir[i])
}
buildFuncExit(b)
}
}