os/os2: wasi target support

core/os/os2/env_wasi.odin

@@ -0,0 +1,186 @@
+#+private
+package os2
+
+import "base:runtime"
+
+import "core:strings"
+import "core:sync"
+import "core:sys/wasm/wasi"
+
+g_env: map[string]string
+g_env_buf: []byte
+g_env_mutex: sync.RW_Mutex
+g_env_error: Error
+g_env_built: bool
+
+build_env :: proc() -> (err: Error) {
+	if g_env_built || g_env_error != nil {
+		return g_env_error
+	}
+
+	sync.guard(&g_env_mutex)
+
+	if g_env_built || g_env_error != nil {
+		return g_env_error
+	}
+
+	defer if err != nil {
+		g_env_error = err
+	}
+
+	num_envs, size_of_envs, _err := wasi.environ_sizes_get()
+	if _err != nil {
+		return _get_platform_error(_err)
+	}
+
+	g_env = make(map[string]string, num_envs, file_allocator()) or_return
+	defer if err != nil { delete(g_env) }
+
+	g_env_buf = make([]byte, size_of_envs, file_allocator()) or_return
+	defer if err != nil { delete(g_env_buf, file_allocator()) }
+
+	TEMP_ALLOCATOR_GUARD()
+
+	envs := make([]cstring, num_envs, temp_allocator()) or_return
+
+	_err = wasi.environ_get(raw_data(envs), raw_data(g_env_buf))
+	if _err != nil {
+		return _get_platform_error(_err)
+	}
+
+	for env in envs {
+		key, _, value := strings.partition(string(env), "=")
+		g_env[key] = value
+	}
+
+	g_env_built = true
+	return
+}
+
+delete_string_if_not_original :: proc(str: string) {
+	start := uintptr(raw_data(g_env_buf))
+	end   := start + uintptr(len(g_env_buf))
+	ptr   := uintptr(raw_data(str))
+	if ptr < start || ptr > end {
+		delete(str, file_allocator())
+	}
+}
+
+@(require_results)
+_lookup_env :: proc(key: string, allocator: runtime.Allocator) -> (value: string, found: bool) {
+	if err := build_env(); err != nil {
+		return
+	}
+
+	sync.shared_guard(&g_env_mutex)
+
+	value = g_env[key] or_return
+	value, _ = clone_string(value, allocator)
+	return
+}
+
+@(require_results)
+_set_env :: proc(key, value: string) -> bool {
+	if err := build_env(); err != nil {
+		return false
+	}
+
+	sync.guard(&g_env_mutex)
+
+	key_ptr, value_ptr, just_inserted, err := map_entry(&g_env, key)
+	if err != nil {
+		return false
+	}
+
+	alloc_err: runtime.Allocator_Error
+
+	if just_inserted {
+		key_ptr^, alloc_err = clone_string(key, file_allocator())
+		if alloc_err != nil {
+			delete_key(&g_env, key)
+			return false
+		}
+
+		value_ptr^, alloc_err = clone_string(value, file_allocator())
+		if alloc_err != nil {
+			delete_key(&g_env, key)
+			delete(key_ptr^, file_allocator())
+			return false
+		}
+
+		return true
+	}
+
+	delete_string_if_not_original(value_ptr^)
+
+	value_ptr^, alloc_err = clone_string(value, file_allocator())
+	if alloc_err != nil {
+		delete_key(&g_env, key)
+		return false
+	}
+
+	return true
+}
+
+@(require_results)
+_unset_env :: proc(key: string) -> bool {
+	if err := build_env(); err != nil {
+		return false
+	}
+
+	sync.guard(&g_env_mutex)
+
+	dkey, dval := delete_key(&g_env, key)
+	delete_string_if_not_original(dkey)
+	delete_string_if_not_original(dval)
+	return true
+}
+
+_clear_env :: proc() {
+	sync.guard(&g_env_mutex)
+
+	for k, v in g_env {
+		delete_string_if_not_original(k)
+		delete_string_if_not_original(v)
+	}
+
+	delete(g_env_buf, file_allocator())
+	g_env_buf = {}
+
+	clear(&g_env)
+
+	g_env_built = true
+}
+
+@(require_results)
+_environ :: proc(allocator: runtime.Allocator) -> []string {
+	if err := build_env(); err != nil {
+		return nil
+	}
+
+	sync.shared_guard(&g_env_mutex)
+
+	envs, alloc_err := make([]string, len(g_env), allocator)
+	if alloc_err != nil {
+		return nil
+	}
+
+	defer if alloc_err != nil {
+		for env in envs {
+			delete(env, allocator)
+		}
+		delete(envs, allocator)
+	}
+
+	i: int
+	for k, v in g_env {
+		defer i += 1
+
+		envs[i], alloc_err = concatenate({k, "=", v}, allocator)
+		if alloc_err != nil {
+			return nil
+		}
+	}
+
+	return envs
+}