cgo: add support for nested structs and unions

cgo/libclang.go

@@ -667,7 +667,13 @@ func tinygo_clang_struct_visitor(c, parent C.GoCXCursor, client_data C.CXClientD
 	bitfieldNum := passed.bitfieldNum
 	bitfieldList := passed.bitfieldList
 	pos := p.getCursorPosition(c)
-	if cursorKind := C.tinygo_clang_getCursorKind(c); cursorKind != C.CXCursor_FieldDecl {
+	switch cursorKind := C.tinygo_clang_getCursorKind(c); cursorKind {
+	case C.CXCursor_FieldDecl:
+		// Expected. This is a regular field.
+	case C.CXCursor_StructDecl, C.CXCursor_UnionDecl:
+		// Ignore. The next field will be the struct/union itself.
+		return C.CXChildVisit_Continue
+	default:
 		cursorKindSpelling := getString(C.clang_getCursorKindSpelling(cursorKind))
 		p.addError(pos, fmt.Sprintf("expected FieldDecl in struct or union, not %s", cursorKindSpelling))
 		return C.CXChildVisit_Continue

cgo/testdata/types.go

@@ -44,7 +44,23 @@ typedef union union2d {
 } union2d_t;
 typedef union {
 	unsigned char arr[10];
-} unionarrary_t;
+} unionarray_t;
+
+// Nested structs and unions.
+typedef struct {
+	point2d_t begin;
+	point2d_t end;
+	int       tag;
+	union {
+		point2d_t area;
+		point3d_t solid;
+	} coord;
+} struct_nested_t;
+typedef union {
+	point3d_t    point;
+	unionarray_t array;
+	union3_t     thing;
+} union_nested_t;
 
 // Enums. These define constant numbers. All these constants must be given the
 // correct number.
@@ -108,7 +124,11 @@ var (
 	_ C.union1_t
 	_ C.union3_t
 	_ C.union2d_t
-	_ C.unionarrary_t
+	_ C.unionarray_t
+
+	// Nested structs and unions.
+	_ C.struct_nested_t
+	_ C.union_nested_t
 
 	// Enums (anonymous and named).
 	_ C.option_t

cgo/testdata/types.out.go

@@ -34,7 +34,7 @@ type C.uint uint32
 type C.ulong uint32
 type C.ulonglong uint64
 type C.ushort uint16
-type C.bitfield_t = C.struct_2
+type C.bitfield_t = C.struct_4
 type C.myIntArray = [10]C.int
 type C.myint = C.int
 type C.option2_t = C.uint
@@ -44,6 +44,13 @@ type C.point2d_t = struct {
 	y C.int
 }
 type C.point3d_t = C.struct_point3d
+type C.struct_nested_t = struct {
+	begin C.point2d_t
+	end   C.point2d_t
+	tag   C.int
+
+	coord C.union_2
+}
 type C.types_t = struct {
 	f   float32
 	d   float64
@@ -52,22 +59,23 @@ type C.types_t = struct {
 type C.union1_t = struct{ i C.int }
 type C.union2d_t = C.union_union2d
 type C.union3_t = C.union_1
-type C.unionarrary_t = struct{ arr [10]C.uchar }
+type C.union_nested_t = C.union_3
+type C.unionarray_t = struct{ arr [10]C.uchar }
 
-func (s *C.struct_2) bitfield_a() C.uchar          { return s.__bitfield_1 & 0x1f }
-func (s *C.struct_2) set_bitfield_a(value C.uchar) { s.__bitfield_1 = s.__bitfield_1&^0x1f | value&0x1f<<0 }
-func (s *C.struct_2) bitfield_b() C.uchar {
+func (s *C.struct_4) bitfield_a() C.uchar          { return s.__bitfield_1 & 0x1f }
+func (s *C.struct_4) set_bitfield_a(value C.uchar) { s.__bitfield_1 = s.__bitfield_1&^0x1f | value&0x1f<<0 }
+func (s *C.struct_4) bitfield_b() C.uchar {
 	return s.__bitfield_1 >> 5 & 0x1
 }
-func (s *C.struct_2) set_bitfield_b(value C.uchar) { s.__bitfield_1 = s.__bitfield_1&^0x20 | value&0x1<<5 }
-func (s *C.struct_2) bitfield_c() C.uchar {
+func (s *C.struct_4) set_bitfield_b(value C.uchar) { s.__bitfield_1 = s.__bitfield_1&^0x20 | value&0x1<<5 }
+func (s *C.struct_4) bitfield_c() C.uchar {
 	return s.__bitfield_1 >> 6
 }
-func (s *C.struct_2) set_bitfield_c(value C.uchar,
+func (s *C.struct_4) set_bitfield_c(value C.uchar,
 
 ) { s.__bitfield_1 = s.__bitfield_1&0x3f | value<<6 }
 
-type C.struct_2 struct {
+type C.struct_4 struct {
 	start        C.uchar
 	__bitfield_1 C.uchar
 
@@ -92,6 +100,17 @@ func (union *C.union_1) unionfield_s() *C.short { return (*C.short)(unsafe.Point
 
 type C.union_1 struct{ $union uint64 }
 
+func (union *C.union_2) unionfield_area() *C.point2d_t  { return (*C.point2d_t)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_2) unionfield_solid() *C.point3d_t { return (*C.point3d_t)(unsafe.Pointer(&union.$union)) }
+
+type C.union_2 struct{ $union [3]uint32 }
+
+func (union *C.union_3) unionfield_point() *C.point3d_t    { return (*C.point3d_t)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_3) unionfield_array() *C.unionarray_t { return (*C.unionarray_t)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_3) unionfield_thing() *C.union3_t     { return (*C.union3_t)(unsafe.Pointer(&union.$union)) }
+
+type C.union_3 struct{ $union [2]uint64 }
+
 func (union *C.union_union2d) unionfield_i() *C.int      { return (*C.int)(unsafe.Pointer(&union.$union)) }
 func (union *C.union_union2d) unionfield_d() *[2]float64 { return (*[2]float64)(unsafe.Pointer(&union.$union)) }
 

testdata/cgo/main.go

@@ -80,6 +80,11 @@ func main() {
 	var _ C.point2d_t = C.point2d_t{x: 3, y: 5}
 	var _ C.point3d_t = C.point3d_t{x: 3, y: 5, z: 7}
 
+	// nested structs/unions
+	var _ C.tagged_union_t
+	var _ C.nested_struct_t
+	var _ C.nested_union_t
+
 	// recursive types, test using a linked list
 	list := &C.list_t{n: 3, next: &C.struct_list_t{n: 6, next: &C.list_t{n: 7, next: nil}}}
 	for list != nil {

testdata/cgo/main.h

@@ -43,6 +43,31 @@ typedef struct {
 	int z;
 } point3d_t;
 
+typedef struct {
+	int tag;
+	union {
+		int a;
+		int b;
+	} u;
+} tagged_union_t;
+
+typedef struct {
+	int x;
+	struct {
+		char red;
+		char green;
+		char blue;
+	} color;
+} nested_struct_t;
+
+typedef union {
+	int x;
+	struct {
+		char a;
+		char b;
+	};
+} nested_union_t;
+
 // linked list
 typedef struct list_t {
 	int           n;