react-native/ReactCommon/jschelpers/JSCHelpers.cpp

215 lines
7.1 KiB
C++

// Copyright 2004-present Facebook. All Rights Reserved.
#include "JSCHelpers.h"
#ifdef WITH_FBSYSTRACE
#include <fbsystrace.h>
#endif
#include <glog/logging.h>
#include "JavaScriptCore.h"
#include "Value.h"
namespace facebook {
namespace react {
namespace {
JSValueRef functionCaller(
JSContextRef ctx,
JSObjectRef function,
JSObjectRef thisObject,
size_t argumentCount,
const JSValueRef arguments[],
JSValueRef* exception) {
const bool isCustomJSC = isCustomJSCPtr(ctx);
auto* f = static_cast<JSFunction*>(JSC_JSObjectGetPrivate(isCustomJSC, function));
return (*f)(ctx, thisObject, argumentCount, arguments);
}
JSClassRef createFuncClass(JSContextRef ctx) {
JSClassDefinition definition = kJSClassDefinitionEmpty;
definition.attributes |= kJSClassAttributeNoAutomaticPrototype;
// Need to duplicate the two different finalizer blocks, since there's no way
// for it to capture this static information.
if (isCustomJSCPtr(ctx)) {
definition.finalize = [](JSObjectRef object) {
auto* function = static_cast<JSFunction*>(JSC_JSObjectGetPrivate(true, object));
delete function;
};
} else {
definition.finalize = [](JSObjectRef object) {
auto* function = static_cast<JSFunction*>(JSC_JSObjectGetPrivate(false, object));
delete function;
};
}
definition.callAsFunction = exceptionWrapMethod<&functionCaller>();
return JSC_JSClassCreate(ctx, &definition);
}
JSObjectRef makeFunction(
JSContextRef ctx,
JSStringRef name,
JSFunction function) {
static JSClassRef kClassDef = NULL, kCustomJSCClassDef = NULL;
JSClassRef *classRef = isCustomJSCPtr(ctx) ? &kCustomJSCClassDef : &kClassDef;
if (!*classRef) {
*classRef = createFuncClass(ctx);
}
// dealloc in kClassDef.finalize
JSFunction *functionPtr = new JSFunction(std::move(function));
auto functionObject = Object(ctx, JSC_JSObjectMake(ctx, *classRef, functionPtr));
functionObject.setProperty("name", Value(ctx, name));
return functionObject;
}
}
JSObjectRef makeFunction(
JSContextRef ctx,
const char* name,
JSFunction function) {
return makeFunction(ctx, String(ctx, name), std::move(function));
}
void installGlobalFunction(
JSGlobalContextRef ctx,
const char* name,
JSFunction function) {
auto jsName = String(ctx, name);
auto functionObj = makeFunction(ctx, jsName, std::move(function));
Object::getGlobalObject(ctx).setProperty(jsName, Value(ctx, functionObj));
}
JSObjectRef makeFunction(
JSGlobalContextRef ctx,
const char* name,
JSObjectCallAsFunctionCallback callback) {
auto jsName = String(ctx, name);
return JSC_JSObjectMakeFunctionWithCallback(ctx, jsName, callback);
}
void installGlobalFunction(
JSGlobalContextRef ctx,
const char* name,
JSObjectCallAsFunctionCallback callback) {
String jsName(ctx, name);
JSObjectRef functionObj = JSC_JSObjectMakeFunctionWithCallback(
ctx, jsName, callback);
Object::getGlobalObject(ctx).setProperty(jsName, Value(ctx, functionObj));
}
void installGlobalProxy(
JSGlobalContextRef ctx,
const char* name,
JSObjectGetPropertyCallback callback) {
JSClassDefinition proxyClassDefintion = kJSClassDefinitionEmpty;
proxyClassDefintion.attributes |= kJSClassAttributeNoAutomaticPrototype;
proxyClassDefintion.getProperty = callback;
const bool isCustomJSC = isCustomJSCPtr(ctx);
JSClassRef proxyClass = JSC_JSClassCreate(isCustomJSC, &proxyClassDefintion);
JSObjectRef proxyObj = JSC_JSObjectMake(ctx, proxyClass, nullptr);
JSC_JSClassRelease(isCustomJSC, proxyClass);
Object::getGlobalObject(ctx).setProperty(name, Value(ctx, proxyObj));
}
void removeGlobal(JSGlobalContextRef ctx, const char* name) {
Object::getGlobalObject(ctx).setProperty(name, Value::makeUndefined(ctx));
}
JSValueRef evaluateScript(JSContextRef context, JSStringRef script, JSStringRef source) {
#ifdef WITH_FBSYSTRACE
fbsystrace::FbSystraceSection s(TRACE_TAG_REACT_CXX_BRIDGE, "evaluateScript");
#endif
JSValueRef exn, result;
result = JSC_JSEvaluateScript(context, script, NULL, source, 0, &exn);
if (result == nullptr) {
formatAndThrowJSException(context, exn, source);
}
return result;
}
#if WITH_FBJSCEXTENSIONS
JSValueRef evaluateSourceCode(JSContextRef context, JSSourceCodeRef source, JSStringRef sourceURL) {
JSValueRef exn, result;
result = JSEvaluateSourceCode(context, source, NULL, &exn);
if (result == nullptr) {
formatAndThrowJSException(context, exn, sourceURL);
}
return result;
}
#endif
void formatAndThrowJSException(JSContextRef context, JSValueRef exn, JSStringRef source) {
Value exception = Value(context, exn);
std::string exceptionText = exception.toString().str();
// The null/empty-ness of source tells us if the JS came from a
// file/resource, or was a constructed statement. The location
// info will include that source, if any.
std::string locationInfo = source != nullptr ? String::ref(context, source).str() : "";
Object exObject = exception.asObject();
auto line = exObject.getProperty("line");
if (line != nullptr && line.isNumber()) {
if (locationInfo.empty() && line.asInteger() != 1) {
// If there is a non-trivial line number, but there was no
// location info, we include a placeholder, and the line
// number.
locationInfo = folly::to<std::string>("<unknown file>:", line.asInteger());
} else if (!locationInfo.empty()) {
// If there is location info, we always include the line
// number, regardless of its value.
locationInfo += folly::to<std::string>(":", line.asInteger());
}
}
if (!locationInfo.empty()) {
exceptionText += " (" + locationInfo + ")";
}
LOG(ERROR) << "Got JS Exception: " << exceptionText;
Value jsStack = exObject.getProperty("stack");
if (jsStack.isNull() || !jsStack.isString()) {
throwJSExecutionException("%s", exceptionText.c_str());
} else {
LOG(ERROR) << "Got JS Stack: " << jsStack.toString().str();
throwJSExecutionExceptionWithStack(
exceptionText.c_str(), jsStack.toString().str().c_str());
}
}
JSValueRef translatePendingCppExceptionToJSError(JSContextRef ctx, const char *exceptionLocation) {
std::ostringstream msg;
try {
throw;
} catch (const std::bad_alloc& ex) {
throw; // We probably shouldn't try to handle this in JS
} catch (const std::exception& ex) {
msg << "C++ Exception in '" << exceptionLocation << "': " << ex.what();
return Value::makeError(ctx, msg.str().c_str());
} catch (const char* ex) {
msg << "C++ Exception (thrown as a char*) in '" << exceptionLocation << "': " << ex;
return Value::makeError(ctx, msg.str().c_str());
} catch (...) {
msg << "Unknown C++ Exception in '" << exceptionLocation << "'";
return Value::makeError(ctx, msg.str().c_str());
}
}
JSValueRef translatePendingCppExceptionToJSError(JSContextRef ctx, JSObjectRef jsFunctionCause) {
try {
auto functionName = Object(ctx, jsFunctionCause).getProperty("name").toString().str();
return translatePendingCppExceptionToJSError(ctx, functionName.c_str());
} catch (...) {
return Value::makeError(ctx, "Failed to get function name while handling exception");
}
}
} }