1 files changed, 120 insertions, 0 deletions
diff --git a/core/sys/darwin/Foundation/NSBlock.odin b/core/sys/darwin/Foundation/NSBlock.odin
new file mode 100644
index 000000000..b9d94bfee
--- /dev/null
+++ b/core/sys/darwin/Foundation/NSBlock.odin
@@ -0,0 +1,120 @@
+package objc_Foundation
+
+import "base:intrinsics"
+import "base:builtin"
+import "core:mem"
+
+@(objc_class="NSBlock")
+Block :: struct {using _: Object}
+
+@(objc_type=Block, objc_name="createGlobal", objc_is_class_method=true)
+Block_createGlobal :: proc (user_data: rawptr, user_proc: proc "c" (user_data: rawptr), allocator := context.allocator) -> (^Block, mem.Allocator_Error) #optional_allocator_error {
+	return Block_createInternal(true, user_data, user_proc, allocator)
+}
+@(objc_type=Block, objc_name="createLocal", objc_is_class_method=true)
+Block_createLocal :: proc (user_data: rawptr, user_proc: proc "c" (user_data: rawptr)) -> ^Block {
+	b, _ := Block_createInternal(false, user_data, user_proc, {})
+	return b
+}
+@(objc_type=Block, objc_name="createGlobalWithParam", objc_is_class_method=true)
+Block_createGlobalWithParam :: proc (user_data: rawptr, user_proc: proc "c" (user_data: rawptr, t: $T), allocator := context.allocator) -> (^Block, mem.Allocator_Error) #optional_allocator_error {
+	return Block_createInternalWithParam(true, user_data, user_proc, allocator)
+}
+@(objc_type=Block, objc_name="createLocalWithParam", objc_is_class_method=true)
+Block_createLocalWithParam :: proc (user_data: rawptr, user_proc: proc "c" (user_data: rawptr, t: $T)) -> ^Block {
+	b, _ := Block_createInternalWithParam(false, user_data, user_proc, {})
+	return b
+}
+
+@(private)
+Internal_Block_Literal_Base :: struct {
+	isa:        ^intrinsics.objc_class,
+	flags:      u32,
+	reserved:   u32,
+	invoke:     rawptr, // contains a pointer to a proc "c" (^Internal_Block_Literal, ...)
+	descriptor: ^Block_Descriptor,
+}
+
+@(private)
+Internal_Block_Literal :: struct {
+	using base: Internal_Block_Literal_Base,
+	// Imported Variables
+	user_proc:  rawptr, // contains a pointer to a proc "c" (user_data: rawptr, ...)
+	user_data:  rawptr,
+}
+
+@(private)
+Block_Descriptor :: struct {
+	reserved:       uint,
+	size:           uint,
+	copy_helper:    proc "c" (dst, src: rawptr),
+	dispose_helper: proc "c" (src: rawptr),
+	signature:      cstring,
+}
+
+@(private)
+global_block_descriptor := Block_Descriptor{
+	reserved = 0,
+	size     = size_of(Internal_Block_Literal),
+}
+
+foreign import libSystem "system:System.framework"
+foreign libSystem {
+	_NSConcreteGlobalBlock: intrinsics.objc_class
+	_NSConcreteStackBlock: intrinsics.objc_class
+}
+
+@(private="file")
+internal_block_literal_make :: proc (is_global: bool, user_data: rawptr, user_proc: rawptr, invoke: rawptr, allocator: mem.Allocator) ->  (b: ^Block, err: mem.Allocator_Error) {
+	_init :: proc(bl: ^Internal_Block_Literal, is_global: bool, user_data: rawptr, user_proc: rawptr, invoke: rawptr) {
+		// Set to true on blocks that have captures (and thus are not true
+		// global blocks) but are known not to escape for various other
+		// reasons. For backward compatibility with old runtimes, whenever
+		// BLOCK_IS_NOESCAPE is set, BLOCK_IS_GLOBAL is set too. Copying a
+		// non-escaping block returns the original block and releasing such a
+		// block is a no-op, which is exactly how global blocks are handled.
+		BLOCK_IS_NOESCAPE      :: (1 << 23)|BLOCK_IS_GLOBAL
+
+		BLOCK_HAS_COPY_DISPOSE :: 1 << 25
+		BLOCK_HAS_CTOR         :: 1 << 26 // helpers have C++ code
+		BLOCK_IS_GLOBAL        :: 1 << 28
+		BLOCK_HAS_STRET        :: 1 << 29 // IFF BLOCK_HAS_SIGNATURE
+		BLOCK_HAS_SIGNATURE    :: 1 << 30
+
+		bl.isa = is_global ? &_NSConcreteGlobalBlock : &_NSConcreteStackBlock
+		bl.flags = BLOCK_IS_GLOBAL if is_global else 0
+		bl.invoke = invoke
+		bl.descriptor = &global_block_descriptor
+		bl.user_proc = auto_cast user_proc
+		bl.user_data = user_data
+	}
+	if is_global {
+		bl := builtin.new (Internal_Block_Literal, allocator) or_return
+		_init(bl, true, user_data, user_proc, invoke)
+		return auto_cast bl, .None
+	} else {
+		// malloc blocks are created by calling 'copy' on a stack block
+		bl: Internal_Block_Literal
+		_init(&bl, false, user_data, user_proc, invoke)
+		return auto_cast copy(cast(^Copying(Block))(&bl)), .None
+	}
+}
+
+@(private="file")
+Block_createInternal :: proc (is_global: bool, user_data: rawptr, user_proc: proc "c" (user_data: rawptr), allocator: mem.Allocator) -> (b: ^Block, err: mem.Allocator_Error) {
+	invoke :: proc "c" (bl: ^Internal_Block_Literal) {
+		user_proc := (proc "c" (rawptr))(bl.user_proc)
+		user_proc(bl.user_data)
+	}
+	return internal_block_literal_make(is_global, user_data, auto_cast user_proc, auto_cast invoke, allocator)
+}
+
+@(private="file")
+Block_createInternalWithParam :: proc (is_global: bool, user_data: rawptr, user_proc: proc "c" (user_data: rawptr, t: $T), allocator: mem.Allocator) -> (b: ^Block, err: mem.Allocator_Error) {
+	invoke :: proc "c" (bl: ^Internal_Block_Literal, t: T) {
+		user_proc := (proc "c" (rawptr, T))(bl.user_proc)
+		user_proc(bl.user_data, t)
+	}
+	return internal_block_literal_make(is_global, user_data, auto_cast user_proc, auto_cast invoke, allocator)
+}
+