1 files changed, 79 insertions, 0 deletions
diff --git a/base/runtime/default_temporary_allocator.odin b/base/runtime/default_temporary_allocator.odin
new file mode 100644
index 000000000..c90f0388d
--- /dev/null
+++ b/base/runtime/default_temporary_allocator.odin
@@ -0,0 +1,79 @@
+package runtime
+
+DEFAULT_TEMP_ALLOCATOR_BACKING_SIZE: int : #config(DEFAULT_TEMP_ALLOCATOR_BACKING_SIZE, 4 * Megabyte)
+NO_DEFAULT_TEMP_ALLOCATOR: bool : ODIN_OS == .Freestanding || ODIN_OS == .JS || ODIN_DEFAULT_TO_NIL_ALLOCATOR
+
+when NO_DEFAULT_TEMP_ALLOCATOR {
+	Default_Temp_Allocator :: struct {}
+	
+	default_temp_allocator_init :: proc(s: ^Default_Temp_Allocator, size: int, backing_allocator := context.allocator) {}
+	
+	default_temp_allocator_destroy :: proc(s: ^Default_Temp_Allocator) {}
+	
+	default_temp_allocator_proc :: nil_allocator_proc
+
+	@(require_results)
+	default_temp_allocator_temp_begin :: proc(loc := #caller_location) -> (temp: Arena_Temp) {
+		return
+	}
+
+	default_temp_allocator_temp_end :: proc(temp: Arena_Temp, loc := #caller_location) {
+	}
+} else {
+	Default_Temp_Allocator :: struct {
+		arena: Arena,
+	}
+	
+	default_temp_allocator_init :: proc(s: ^Default_Temp_Allocator, size: int, backing_allocator := context.allocator) {
+		_ = arena_init(&s.arena, uint(size), backing_allocator)
+	}
+
+	default_temp_allocator_destroy :: proc(s: ^Default_Temp_Allocator) {
+		if s != nil {
+			arena_destroy(&s.arena)
+			s^ = {}
+		}
+	}
+
+	default_temp_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode,
+	                                    size, alignment: int,
+	                                    old_memory: rawptr, old_size: int, loc := #caller_location) -> (data: []byte, err: Allocator_Error) {
+
+		s := (^Default_Temp_Allocator)(allocator_data)
+		return arena_allocator_proc(&s.arena, mode, size, alignment, old_memory, old_size, loc)
+	}
+
+	@(require_results)
+	default_temp_allocator_temp_begin :: proc(loc := #caller_location) -> (temp: Arena_Temp) {
+		if context.temp_allocator.data == &global_default_temp_allocator_data {
+			temp = arena_temp_begin(&global_default_temp_allocator_data.arena, loc)
+		}
+		return
+	}
+
+	default_temp_allocator_temp_end :: proc(temp: Arena_Temp, loc := #caller_location) {
+		arena_temp_end(temp, loc)
+	}
+
+	@(fini, private)
+	_destroy_temp_allocator_fini :: proc() {
+		default_temp_allocator_destroy(&global_default_temp_allocator_data)
+	}
+}
+
+@(deferred_out=default_temp_allocator_temp_end)
+DEFAULT_TEMP_ALLOCATOR_TEMP_GUARD :: #force_inline proc(ignore := false, loc := #caller_location) -> (Arena_Temp, Source_Code_Location) {
+	if ignore {
+		return {}, loc
+	} else {
+		return default_temp_allocator_temp_begin(loc), loc
+	}
+}
+
+
+default_temp_allocator :: proc(allocator: ^Default_Temp_Allocator) -> Allocator {
+	return Allocator{
+		procedure = default_temp_allocator_proc,
+		data      = allocator,
+	}
+}