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n-api: change napi_callback to return napi_value
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Change `napi_callback` to return `napi_value` directly instead of
requiring `napi_set_return_value`.

When we invoke the callback, we will check the return value and
call `SetReturnValue` ourselves. If the callback returns `NULL`,
we don't set the return value in v8 which would have the same
effect as previously if the callback didn't call
`napi_set_return_value`. Seems to be a more natural way
to handle return values from callbacks. As a consequence,
remove `napi_set_return_value`.

Add a `napi_value` to `napi_property_descriptor` to support string
values which couldn't be passed in the `utf8name` parameter or
symbols as property names. Class names, however, cannot be symbols
so this `napi_value` must be a string type in that case.

Remove all of the `napi_callback_info` helpers except for
`napi_get_cb_info` and make all the parameters to
`napi_get_cb_info` optional except for argc.

Update all the test collateral according to these changes.
Also add `test/addons-napi/common.h` to house some common macros
for wrapping N-API calls and error handling.

Backport-PR-URL: #19447
PR-URL: #12248
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
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@boingoing @MylesBorins
boingoing authored and MylesBorins committed Apr 16, 2018
1 parent a6af97f commit c127b71
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Showing 32 changed files with 939 additions and 1,590 deletions.
275 changes: 121 additions & 154 deletions src/node_api.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,70 @@ class napi_env__ {
napi_extended_error_info last_error;
};

#define RETURN_STATUS_IF_FALSE(env, condition, status) \
do { \
if (!(condition)) { \
return napi_set_last_error((env), (status)); \
} \
} while (0)

#define CHECK_ENV(env) \
if ((env) == nullptr) { \
node::FatalError(__func__, "environment(env) must not be null"); \
}

#define CHECK_ARG(env, arg) \
RETURN_STATUS_IF_FALSE((env), ((arg) != nullptr), napi_invalid_arg)

#define CHECK_MAYBE_EMPTY(env, maybe, status) \
RETURN_STATUS_IF_FALSE((env), !((maybe).IsEmpty()), (status))

#define CHECK_MAYBE_NOTHING(env, maybe, status) \
RETURN_STATUS_IF_FALSE((env), !((maybe).IsNothing()), (status))

// NAPI_PREAMBLE is not wrapped in do..while: try_catch must have function scope
#define NAPI_PREAMBLE(env) \
CHECK_ENV((env)); \
RETURN_STATUS_IF_FALSE((env), (env)->last_exception.IsEmpty(), \
napi_pending_exception); \
napi_clear_last_error((env)); \
v8impl::TryCatch try_catch((env))

#define CHECK_TO_TYPE(env, type, context, result, src, status) \
do { \
auto maybe = v8impl::V8LocalValueFromJsValue((src))->To##type((context)); \
CHECK_MAYBE_EMPTY((env), maybe, (status)); \
(result) = maybe.ToLocalChecked(); \
} while (0)

#define CHECK_TO_OBJECT(env, context, result, src) \
CHECK_TO_TYPE((env), Object, (context), (result), (src), napi_object_expected)

#define CHECK_TO_STRING(env, context, result, src) \
CHECK_TO_TYPE((env), String, (context), (result), (src), napi_string_expected)

#define CHECK_TO_NUMBER(env, context, result, src) \
CHECK_TO_TYPE((env), Number, (context), (result), (src), napi_number_expected)

#define CHECK_TO_BOOL(env, context, result, src) \
CHECK_TO_TYPE((env), Boolean, (context), (result), (src), \
napi_boolean_expected)

#define CHECK_NEW_FROM_UTF8_LEN(env, result, str, len) \
do { \
auto str_maybe = v8::String::NewFromUtf8( \
(env)->isolate, (str), v8::NewStringType::kInternalized, (len)); \
CHECK_MAYBE_EMPTY((env), str_maybe, napi_generic_failure); \
(result) = str_maybe.ToLocalChecked(); \
} while (0)

#define CHECK_NEW_FROM_UTF8(env, result, str) \
CHECK_NEW_FROM_UTF8_LEN((env), (result), (str), -1)

#define GET_RETURN_STATUS(env) \
(!try_catch.HasCaught() ? napi_ok \
: napi_set_last_error((env), napi_pending_exception))

namespace v8impl {

// convert from n-api property attributes to v8::PropertyAttribute
Expand Down Expand Up @@ -129,6 +193,22 @@ v8::Local<v8::Value> V8LocalValueFromJsValue(napi_value v) {
return local;
}

static inline napi_status V8NameFromPropertyDescriptor(napi_env env,
const napi_property_descriptor* p,
v8::Local<v8::Name>* result) {
if (p->utf8name != nullptr) {
CHECK_NEW_FROM_UTF8(env, *result, p->utf8name);
} else {
v8::Local<v8::Value> property_value =
v8impl::V8LocalValueFromJsValue(p->name);

RETURN_STATUS_IF_FALSE(env, property_value->IsName(), napi_name_expected);
*result = property_value.As<v8::Name>();
}

return napi_ok;
}

// Adapter for napi_finalize callbacks.
class Finalizer {
protected:
Expand Down Expand Up @@ -363,13 +443,19 @@ class CallbackWrapperBase : public CallbackWrapper {
v8::Local<v8::External>::Cast(
_cbdata->GetInternalField(kInternalFieldIndex))->Value());
v8::Isolate* isolate = _cbinfo.GetIsolate();

napi_env env = static_cast<napi_env>(
v8::Local<v8::External>::Cast(
_cbdata->GetInternalField(kEnvIndex))->Value());

// Make sure any errors encountered last time we were in N-API are gone.
napi_clear_last_error(env);
cb(env, cbinfo_wrapper);

napi_value result = cb(env, cbinfo_wrapper);

if (result != nullptr) {
this->SetReturnValue(result);
}

if (!env->last_exception.IsEmpty()) {
isolate->ThrowException(
Expand Down Expand Up @@ -610,75 +696,12 @@ void napi_module_register(napi_module* mod) {
node::node_module_register(nm);
}

#define RETURN_STATUS_IF_FALSE(env, condition, status) \
do { \
if (!(condition)) { \
return napi_set_last_error((env), (status)); \
} \
} while (0)

#define CHECK_ENV(env) \
if ((env) == nullptr) { \
node::FatalError(__func__, "environment(env) must not be null"); \
}

#define CHECK_ARG(env, arg) \
RETURN_STATUS_IF_FALSE((env), ((arg) != nullptr), napi_invalid_arg)

#define CHECK_MAYBE_EMPTY(env, maybe, status) \
RETURN_STATUS_IF_FALSE((env), !((maybe).IsEmpty()), (status))

#define CHECK_MAYBE_NOTHING(env, maybe, status) \
RETURN_STATUS_IF_FALSE((env), !((maybe).IsNothing()), (status))

// NAPI_PREAMBLE is not wrapped in do..while: try_catch must have function scope
#define NAPI_PREAMBLE(env) \
CHECK_ENV((env)); \
RETURN_STATUS_IF_FALSE((env), (env)->last_exception.IsEmpty(), \
napi_pending_exception); \
napi_clear_last_error((env)); \
v8impl::TryCatch try_catch((env))

#define CHECK_TO_TYPE(env, type, context, result, src, status) \
do { \
auto maybe = v8impl::V8LocalValueFromJsValue((src))->To##type((context)); \
CHECK_MAYBE_EMPTY((env), maybe, (status)); \
(result) = maybe.ToLocalChecked(); \
} while (0)

#define CHECK_TO_OBJECT(env, context, result, src) \
CHECK_TO_TYPE((env), Object, (context), (result), (src), napi_object_expected)

#define CHECK_TO_STRING(env, context, result, src) \
CHECK_TO_TYPE((env), String, (context), (result), (src), napi_string_expected)

#define CHECK_TO_NUMBER(env, context, result, src) \
CHECK_TO_TYPE((env), Number, (context), (result), (src), napi_number_expected)

#define CHECK_TO_BOOL(env, context, result, src) \
CHECK_TO_TYPE((env), Boolean, (context), (result), (src), \
napi_boolean_expected)

#define CHECK_NEW_FROM_UTF8_LEN(env, result, str, len) \
do { \
auto str_maybe = v8::String::NewFromUtf8( \
(env)->isolate, (str), v8::NewStringType::kInternalized, (len)); \
CHECK_MAYBE_EMPTY((env), str_maybe, napi_generic_failure); \
result = str_maybe.ToLocalChecked(); \
} while (0)

#define CHECK_NEW_FROM_UTF8(env, result, str) \
CHECK_NEW_FROM_UTF8_LEN((env), (result), (str), -1)

#define GET_RETURN_STATUS(env) \
(!try_catch.HasCaught() ? napi_ok \
: napi_set_last_error((env), napi_pending_exception))

// Warning: Keep in-sync with napi_status enum
const char* error_messages[] = {nullptr,
"Invalid pointer passed as argument",
"An object was expected",
"A string was expected",
"A string or symbol was expected",
"A function was expected",
"A number was expected",
"A boolean was expected",
Expand Down Expand Up @@ -795,8 +818,14 @@ napi_status napi_define_class(napi_env env,
continue;
}

v8::Local<v8::String> property_name;
CHECK_NEW_FROM_UTF8(env, property_name, p->utf8name);
v8::Local<v8::Name> property_name;
napi_status status =
v8impl::V8NameFromPropertyDescriptor(env, p, &property_name);

if (status != napi_ok) {
return napi_set_last_error(env, status);
}

v8::PropertyAttribute attributes =
v8impl::V8PropertyAttributesFromDescriptor(p);

Expand Down Expand Up @@ -824,7 +853,6 @@ napi_status napi_define_class(napi_env env,
v8impl::FunctionCallbackWrapper::Invoke,
cbdata,
v8::Signature::New(isolate, tpl));
t->SetClassName(property_name);

tpl->PrototypeTemplate()->Set(property_name, t, attributes);
} else {
Expand Down Expand Up @@ -857,18 +885,6 @@ napi_status napi_define_class(napi_env env,
return GET_RETURN_STATUS(env);
}

napi_status napi_set_return_value(napi_env env,
napi_callback_info cbinfo,
napi_value value) {
NAPI_PREAMBLE(env);

v8impl::CallbackWrapper* info =
reinterpret_cast<v8impl::CallbackWrapper*>(cbinfo);

info->SetReturnValue(value);
return GET_RETURN_STATUS(env);
}

napi_status napi_get_property_names(napi_env env,
napi_value object,
napi_value* result) {
Expand Down Expand Up @@ -1104,11 +1120,16 @@ napi_status napi_define_properties(napi_env env,
for (size_t i = 0; i < property_count; i++) {
const napi_property_descriptor* p = &properties[i];

v8::Local<v8::Name> name;
CHECK_NEW_FROM_UTF8(env, name, p->utf8name);
v8::Local<v8::Name> property_name;
napi_status status =
v8impl::V8NameFromPropertyDescriptor(env, p, &property_name);

if (status != napi_ok) {
return napi_set_last_error(env, status);
}

v8::PropertyAttribute attributes =
v8impl::V8PropertyAttributesFromDescriptor(p);
v8impl::V8PropertyAttributesFromDescriptor(p);

if (p->getter != nullptr || p->setter != nullptr) {
v8::Local<v8::Object> cbdata = v8impl::CreateAccessorCallbackData(
Expand All @@ -1119,7 +1140,7 @@ napi_status napi_define_properties(napi_env env,

auto set_maybe = obj->SetAccessor(
context,
name,
property_name,
p->getter ? v8impl::GetterCallbackWrapper::Invoke : nullptr,
p->setter ? v8impl::SetterCallbackWrapper::Invoke : nullptr,
cbdata,
Expand All @@ -1138,8 +1159,8 @@ napi_status napi_define_properties(napi_env env,
v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New(
isolate, v8impl::FunctionCallbackWrapper::Invoke, cbdata);

auto define_maybe =
obj->DefineOwnProperty(context, name, t->GetFunction(), attributes);
auto define_maybe = obj->DefineOwnProperty(
context, property_name, t->GetFunction(), attributes);

if (!define_maybe.FromMaybe(false)) {
return napi_set_last_error(env, napi_generic_failure);
Expand All @@ -1148,7 +1169,7 @@ napi_status napi_define_properties(napi_env env,
v8::Local<v8::Value> value = v8impl::V8LocalValueFromJsValue(p->value);

auto define_maybe =
obj->DefineOwnProperty(context, name, value, attributes);
obj->DefineOwnProperty(context, property_name, value, attributes);

if (!define_maybe.FromMaybe(false)) {
return napi_set_last_error(env, napi_invalid_arg);
Expand Down Expand Up @@ -1441,33 +1462,24 @@ napi_status napi_get_cb_info(
napi_value* this_arg, // [out] Receives the JS 'this' arg for the call
void** data) { // [out] Receives the data pointer for the callback.
CHECK_ENV(env);
CHECK_ARG(env, argc);
CHECK_ARG(env, argv);
CHECK_ARG(env, this_arg);
CHECK_ARG(env, data);

v8impl::CallbackWrapper* info =
reinterpret_cast<v8impl::CallbackWrapper*>(cbinfo);

info->Args(argv, std::min(*argc, info->ArgsLength()));
*argc = info->ArgsLength();
*this_arg = info->This();
*data = info->Data();

return napi_ok;
}

napi_status napi_get_cb_args_length(napi_env env,
napi_callback_info cbinfo,
size_t* result) {
// Omit NAPI_PREAMBLE and GET_RETURN_STATUS because no V8 APIs are called.
CHECK_ENV(env);
CHECK_ARG(env, result);

v8impl::CallbackWrapper* info =
reinterpret_cast<v8impl::CallbackWrapper*>(cbinfo);
if (argv != nullptr) {
CHECK_ARG(env, argc);
info->Args(argv, std::min(*argc, info->ArgsLength()));
}
if (argc != nullptr) {
*argc = info->ArgsLength();
}
if (this_arg != nullptr) {
*this_arg = info->This();
}
if (data != nullptr) {
*data = info->Data();
}

*result = info->ArgsLength();
return napi_ok;
}

Expand All @@ -1485,51 +1497,6 @@ napi_status napi_is_construct_call(napi_env env,
return napi_ok;
}

// copy encoded arguments into provided buffer or return direct pointer to
// encoded arguments array?
napi_status napi_get_cb_args(napi_env env,
napi_callback_info cbinfo,
napi_value* buf,
size_t bufsize) {
// Omit NAPI_PREAMBLE and GET_RETURN_STATUS because no V8 APIs are called.
CHECK_ENV(env);
CHECK_ARG(env, buf);

v8impl::CallbackWrapper* info =
reinterpret_cast<v8impl::CallbackWrapper*>(cbinfo);

info->Args(buf, bufsize);
return napi_ok;
}

napi_status napi_get_cb_this(napi_env env,
napi_callback_info cbinfo,
napi_value* result) {
// Omit NAPI_PREAMBLE and GET_RETURN_STATUS because no V8 APIs are called.
CHECK_ENV(env);
CHECK_ARG(env, result);

v8impl::CallbackWrapper* info =
reinterpret_cast<v8impl::CallbackWrapper*>(cbinfo);

*result = info->This();
return napi_ok;
}

napi_status napi_get_cb_data(napi_env env,
napi_callback_info cbinfo,
void** result) {
// Omit NAPI_PREAMBLE and GET_RETURN_STATUS because no V8 APIs are called.
CHECK_ENV(env);
CHECK_ARG(env, result);

v8impl::CallbackWrapper* info =
reinterpret_cast<v8impl::CallbackWrapper*>(cbinfo);

*result = info->Data();
return napi_ok;
}

napi_status napi_call_function(napi_env env,
napi_value recv,
napi_value func,
Expand Down
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