react-native/ReactCommon/cxxreact/JSCHelpers.cpp

144 lines
4.8 KiB
C++

// Copyright 2004-present Facebook. All Rights Reserved.
#include "JSCHelpers.h"
#include <JavaScriptCore/JSStringRef.h>
#include <folly/String.h>
#include <glog/logging.h>
#include "SystraceSection.h"
#include "Value.h"
namespace facebook {
namespace react {
void installGlobalFunction(
JSGlobalContextRef ctx,
const char* name,
JSObjectCallAsFunctionCallback callback) {
JSStringRef jsName = JSStringCreateWithUTF8CString(name);
JSObjectRef functionObj = JSObjectMakeFunctionWithCallback(
ctx, jsName, callback);
JSObjectRef globalObject = JSContextGetGlobalObject(ctx);
JSObjectSetProperty(ctx, globalObject, jsName, functionObj, 0, NULL);
JSStringRelease(jsName);
}
JSValueRef makeJSCException(
JSContextRef ctx,
const char* exception_text) {
JSStringRef message = JSStringCreateWithUTF8CString(exception_text);
JSValueRef exceptionString = JSValueMakeString(ctx, message);
JSStringRelease(message);
return JSValueToObject(ctx, exceptionString, NULL);
}
String jsStringFromBigString(const JSBigString& bigstr) {
if (bigstr.isAscii()) {
return String::createExpectingAscii(bigstr.c_str(), bigstr.size());
} else {
return String(bigstr.c_str());
}
}
JSValueRef evaluateScript(JSContextRef context, JSStringRef script, JSStringRef source) {
SystraceSection s("evaluateScript");
JSValueRef exn, result;
result = 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(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 makeJSError(JSContextRef ctx, const char *error) {
JSValueRef nestedException = nullptr;
JSValueRef args[] = { Value(ctx, String(error)) };
JSObjectRef errorObj = JSObjectMakeError(ctx, 1, args, &nestedException);
if (nestedException != nullptr) {
return std::move(args[0]);
}
return errorObj;
}
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 makeJSError(ctx, msg.str().c_str());
} catch (const char* ex) {
msg << "C++ Exception (thrown as a char*) in '" << exceptionLocation << "': " << ex;
return makeJSError(ctx, msg.str().c_str());
} catch (...) {
msg << "Unknown C++ Exception in '" << exceptionLocation << "'";
return makeJSError(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 makeJSError(ctx, "Failed to get function name while handling exception");
}
}
} }