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| author | Marc Vertes <mvertes@free.fr> | 2026-01-14 18:44:17 +0100 |
|---|---|---|
| committer | Marc Vertes <mvertes@free.fr> | 2026-01-14 18:44:17 +0100 |
| commit | 31e3793202402fda21905027c18ebfa5c8d8c832 (patch) | |
| tree | dbe52ae31fada099bc65fcd9c7d61f6266c6ba78 /vm/vm.go | |
| parent | de3baf0e06862f0420950f025b3328068f3b6df2 (diff) | |
fix: improve handling of indirections
Added 2 VM instructions, FnewE variant of Fnew with a dereference,
and FieldE, variant of Field with dereference.
It's now possible to pointers in structs and literal composites.
Diffstat (limited to 'vm/vm.go')
| -rw-r--r-- | vm/vm.go | 11 |
1 files changed, 11 insertions, 0 deletions
@@ -32,10 +32,12 @@ const ( Dup // addr -- value ; value = mem[addr] Fdup // addr -- value ; value = mem[addr] Fnew // -- x; x = new mem[$1] + FnewE // -- x; x = new mem[$1].Elem() Equal // n1 n2 -- cond ; cond = n1 == n2 EqualSet // n1 n2 -- n1 cond ; cond = n1 == n2 Exit // -- ; Field // s -- f ; f = s.FieldIndex($1, ...) + FieldE // s -- f ; f = s.FieldIndex($1, ...) FieldSet // s d -- s ; s.FieldIndex($1, ...) = d FieldFset // s i v -- s; s.FieldIndex(i) = v Greater // n1 n2 -- cond; cond = n1 > n2 @@ -173,6 +175,8 @@ func (m *Machine) Run() (err error) { mem = append(mem, mem[c.Arg[0]+fp-1]) case Fnew: mem = append(mem, NewValue(mem[c.Arg[0]].Type, c.Arg[1:]...)) + case FnewE: + mem = append(mem, NewValue(mem[c.Arg[0]].Type.Elem(), c.Arg[1:]...)) case Field: fv := mem[sp-1].FieldByIndex(c.Arg) if !fv.CanSet() { @@ -180,6 +184,13 @@ func (m *Machine) Run() (err error) { fv = reflect.NewAt(fv.Type(), unsafe.Pointer(fv.UnsafeAddr())).Elem() } mem[sp-1].Value = fv + case FieldE: + fv := mem[sp-1].Value.Elem().FieldByIndex(c.Arg) + if !fv.CanSet() { + // Normally private fields can not bet set via reflect. Override this limitation. + fv = reflect.NewAt(fv.Type(), unsafe.Pointer(fv.UnsafeAddr())).Elem() + } + mem[sp-1].Value = fv case FieldSet: fv := mem[sp-2].FieldByIndex(c.Arg) if !fv.CanSet() { |