union: support embedded field

cl/codebuild.go

@@ -42,35 +42,58 @@ func newUnionBuilder() *unionBuilder {
  return &unionBuilder{}
 }
 
+func unionEmbeddedField(ctx *blockCtx, fields []*gox.UnionField, t *types.Named, off int) []*gox.UnionField {
+ o := t.Underlying().(*types.Struct)
+ for i, n := 0, o.NumFields(); i < n; i++ {
+ fld := o.Field(i)
+ fldType := fld.Type()
+ if fld.Embedded() {
+ fields = unionEmbeddedField(ctx, fields, fldType.(*types.Named), off)
+ } else {
+ fields = append(fields, &gox.UnionField{
+ Name: fld.Name(),
+ Off: off,
+ Type: fldType,
+ })
+ }
+ off += ctx.sizeof(fldType)
+ }
+ return fields
+}
+
 func (p *unionBuilder) Type(ctx *blockCtx, t *types.Named) *types.Struct {
  var fldLargest *gox.UnionField
- var lenLargest int
- for _, fld := range p.fields {
+ var fields = p.fields
+ var lenLargest, n = 0, len(fields)
+ for i := 0; i < n; i++ {
+ fld := fields[i]
  if len := ctx.sizeof(fld.Type); len > lenLargest {
  fldLargest, lenLargest = fld, len
  }
+ if fld.Name == "" { // embedded
+ fields = unionEmbeddedField(ctx, fields, fld.Type.(*types.Named), 0)
+ }
  }
  flds := make([]*types.Var, 0, 1)
  if fldLargest != nil {
  pkg := ctx.pkg
- pkg.SetVFields(t, gox.NewUnionFields(p.fields))
+ pkg.SetVFields(t, gox.NewUnionFields(fields))
  fld := types.NewField(fldLargest.Pos, pkg.Types, fldLargest.Name, fldLargest.Type, false)
  flds = append(flds, fld)
  }
  return types.NewStruct(flds, nil)
 }
 
 func (p *unionBuilder) Field(ctx *blockCtx, pos token.Pos, typ types.Type, name string, embedded bool) {
+ if embedded {
+ name = ""
+ }
  fld := &gox.UnionField{
  Name: name,
- Off: 0, // TODO
  Type: typ,
  Pos: pos,
  }
  p.fields = append(p.fields, fld)
- if name == "" {
- log.Fatalln("unionBuilder.Field TODO: embedded")
- }
 }
 
 // -----------------------------------------------------------------------------

cl/type_and_var.go

@@ -114,6 +114,7 @@ func toUnionType(ctx *blockCtx, t *types.Named, unio *ast.Node, ns string) types
  }
  break
  }
+ case ast.IndirectFieldDecl:
  default:
  log.Fatalln("toUnionType: unknown field kind =", decl.Kind)
  }

testdata/union/union.c

@@ -1,11 +1,17 @@
 #include <stdio.h>
 
 typedef union {
- long a;
+ int a;
  unsigned short b;
  struct bar {
  unsigned short low, high;
  } c;
+ struct {
+ unsigned short low;
+ struct {
+ unsigned short high;
+ };
+ };
 } foo;
 
 int main() {
@@ -16,5 +22,16 @@ int main() {
  printf(
  "foo.a = %d, foo.b = %d, foo.c.low = %d, foo.c.high = %d\n",
  foo.a, foo.b, foo.c.low, foo.c.high);
+ printf(
+ "foo.low = %d, foo.high = %d\n",
+ foo.low, foo.high);
+ foo.low = 5;
+ foo.high = 6;
+ printf(
+ "foo.a = %d, foo.b = %d, foo.c.low = %d, foo.c.high = %d\n",
+ foo.a, foo.b, foo.c.low, foo.c.high);
+ printf(
+ "foo.low = %d, foo.high = %d\n",
+ foo.low, foo.high);
  return 0;
 }