I am writing some pass using LLVM. I recognize all CallInst in functions using
bool runOnFunction(Function &F) override {
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; BB++) {
for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE; BI++) {
if (isa<CallInst>(&(*BI))) {
CallInst *CI = dyn_cast<CallInst>(BI);
// TODO:
}
}
}
return true;
}
However, I want to check if the called function is defined by user because I want to focus on such Instruction. Could u get me some advice?
Related
I have found this piece of code showing how to call a blueprint function from C++:
UFUnction* Func = Obj->GetClass()->FindFunction(FName("FuncName"));
if(Func == nullptr){return;}
FStructOnScope FuncParam(Func);
UProperty* ReturnProp = nullptr;
for (TFieldIterator<UProperty> It(Func); It; ++It)
{
UProperty* Prop = *It;
if (Prop->HasAnyPropertyFlags(CPF_ReturnParm))
{
ReturnProp = Prop;
}
else
{
//FillParam here
}
}
Obj->ProcessEvent(Func, FuncParam.GetStructMemory());
But… I don’t know how to //Fillparam here.
How can I fill the FuncParam with the parameters that I need to pass?
I am storing js callbacks in vector:
std::vector<std::unique_ptr<Persistent<Function>>> callbacks;
Everything is working fine. The problem is that I do not want to store duplicated callbacks because I do not want to notify the same callback twice. I have to compare them somehow. Here is my full function but that does not work:
void ProcessCallback(const FunctionCallbackInfo<Value>& args)
{
std::string returnInfo;
Isolate* isolate = args.GetIsolate();
Local<Function> notifyFunction = Local<Function>::Cast(args[0]);
auto predicate = [&](const std::unique_ptr<Persistent<Function>>& c)
{
return c->Get(isolate)->StrictEquals(notifyFunction);
};
auto it = std::find_if(callbacks.begin(), callbacks.end(), predicate);
if (it == callbacks.end())
{
returnInfo = "Did not find callback. Adding..." + std::to_string(callbacks.size());
auto persistentCallback = std::make_unique<Persistent<Function>>(isolate, notifyFunction);
callbacks.emplace_back(std::move(persistentCallback));
}
else
{
returnInfo = "Callback already exist in a list.\n";
}
args.GetReturnValue().Set(String::NewFromUtf8(isolate, returnInfo.c_str()).ToLocalChecked());
}
In js:
function callback(msg) {
console.log(msg);
}
let addon = require('./build/Release/addon');
console.log(addon.on(callback));
console.log(addon.on(callback));
Is there something that I can rely on to uniquely identify function that is passed from js? Thanks.
It's not the first time I find myself in the following situation:
bool a = some_very_long_computation;
bool b = another_very_long_computation;
while (a && b) {
...
a = some_very_long_computation;
b = another_very_long_computation;
}
I don't want to compute everything in while condition, since computations are long and I want to give them appropriate names.
I don't want to create helper functions, because computation uses many local variables, and passing them all will make the code much less readable (and it will be some_huge_call).
It's unknown whether loop body will be executed at least once.
What is a good pattern in such situation? Currently I face it in C++, but I've encountered this in other languages as well. I can solve it by using additional variable isFirstPass, but it looks ugly (and, I guess, will cause some warnings):
bool a, b;
bool isFirstPass = true;
do {
if (!isFirstPass) {
...
} else {
isFirstPass = false;
}
a = some_very_long_computation;
b = another_very_long_computation;
} while (a && b);
The direct simplification of your code is:
while (
some_very_long_computation &&
another_very_long_computation
) {
...
}
If you want to keep the variables a and b:
bool a, b;
while (
(a = some_very_long_computation) &&
(b = another_very_long_computation)
) {
...
}
If you don't want to put the conditions into the while condition:
while (true) {
bool a = some_very_long_computation;
bool b = another_very_long_computation;
if (!(a && b)) {
break;
}
...
}
You could also create helper lambdas (which have access to local variables):
auto fa = [&]() { return some_very_long_computation; };
auto fb = [&]() { return another_very_long_computation; };
while (fa() && fb()) {
...
}
I'm having some trouble with the following method and I need some help trying to figure out what I am doing wrong.
I want to return a reference to a Value in a document. I am passing the Document from outside the function so that when I read a json file into it I don't "lose it".
const rapidjson::Value& CTestManager::GetOperations(rapidjson::Document& document)
{
const Value Null(kObjectType);
if (m_Tests.empty())
return Null;
if (m_current > m_Tests.size() - 1)
return Null;
Test& the_test = m_Tests[m_current];
CMyFile fp(the_test.file.c_str()); // non-Windows use "r"
if (!fp.is_open())
return Null;
u32 operations_count = 0;
CFileBuffer json(fp);
FileReadStream is(fp.native_handle(), json, json.size());
if (document.ParseInsitu<kParseCommentsFlag>(json).HasParseError())
{
(...)
}
else
{
if (!document.IsObject())
{
(...)
}
else
{
auto tests = document.FindMember("td_tests");
if (tests != document.MemberEnd())
{
for (SizeType i = 0; i < tests->value.Size(); i++)
{
const Value& test = tests->value[i];
if (test["id"].GetInt() == the_test.id)
{
auto it = test.FindMember("operations");
if (it != test.MemberEnd())
{
//return it->value; is this legitimate?
return test["operations"];
}
return Null;
}
}
}
}
}
return Null;
}
Which I am calling like this:
Document document;
auto operations = TestManager().GetOperations(document);
When I inspect the value of test["operations"] inside the function I can see everything I would expect (debug code removed from the abode code).
When I inspect the returned value outside the function I can see that it's an array (which I expect). the member count int the array is correct as well, but when print it out, I only see garbage instead.
When I "print" the Value to a string inside the methods, I get what I expect (i.e. a well formated json), but when I do it outside all keys show up as "IIIIIIII" and values that aren't strings show up correctly.
rapidjson::StringBuffer strbuf2;
rapidjson::PrettyWriter<rapidjson::StringBuffer> writer2(strbuf2);
ops->Accept(writer2);
As this didn't work I decided to change the method to receive a Value as a parameter and do a deep copy into it like this
u32 CTestManager::GetOperationsEx(rapidjson::Document& document, rapidjson::Value& operations)
{
(...)
if (document.ParseInsitu<kParseCommentsFlag>(json).HasParseError())
{
(...)
}
else
{
if (!document.IsObject())
{
(...)
}
else
{
auto tests = document.FindMember("tests");
if (tests != document.MemberEnd())
{
for (SizeType i = 0; i < tests->value.Size(); i++)
{
const Value& test = tests->value[i];
if (test["id"].GetInt() == the_test.id)
{
const Value& opv = test["operations"];
Document::AllocatorType& allocator = document.GetAllocator();
operations.CopyFrom(opv, allocator); //would Swap work?
return operations.Size();
}
}
}
}
}
return 0;
}
Which I'm calling like this:
Document document;
Value operations(kObjectType);
u32 count = TestManager().GetOperationsEx(document, operations);
But... I get same thing!!!!
I know that it's going to be something silly but I can't put my hands on it!
Any ideas?
The problem in this case lies with the use of ParseInSitu. When any of the GetOperations exist the CFileBuffer loses scope and is cleaned up. Because the json is being parsed in-situ when the buffer to the file goes, so goes the data.
I'm using C# to call methods from an dll file to record video.
This is the Marshal methods file
http://pastebin.com/YrVvBfZ9
This is my CameraUtilities file
http://pastebin.com/0AZNtnhk
This is my camera file
http://pastebin.com/ZE3HD1zq
When I call StartRecord method (in camera file) to start Record video.
public void StartRecord()
{
if (this.ListCameras != null)
{
bool bRes = true;
try
{
int tmpError = -1;
m_tmpContext = new IntPtr();
m_handle = new GCHandle();
m_callBackChannels = new ulong[m_ListCameras.Length];
for (int i = 0; i < m_ListCameras.Length; i++)
{
m_callBackChannels[i] = 10;
cameraCurrentIndex = 0;
IntPtr channelHandle = T1800.T18_ChannelOpen(cameraCurrentIndex);
m_ListCameras[cameraCurrentIndex].ChannelHandle = channelHandle;
T1800.T18_CaptureIFrame(m_ListCameras[i].ChannelHandle);
m_ListCameras[i].BeginRecord();
if (AllowRecordVideo)
{
m_del = new T1800.STREAM_READ_CALLBACK(StreamReadCallBack);
m_tmpContext = m_ListCameras[i].ChannelHandle;
tmpError = T1800.T18_RegisterStreamReadCallback(m_del, ref m_tmpContext);
}
}
if (tmpError == -1) bRes = false;
}
catch (Exception ex)
{
Log.Logger.Error(ex);
bRes = false;
}
}
}
It throw an exception
- System.Runtime.InteropServices.MarshalDirectiveException: Invalid PInvoke calling convention.
Thiscall requires that the first parameter is present and can be enregistered.
at System.Runtime.InteropServices.Marshal.GetFunctionPointerForDelegateInternal(Delegate d)
at System.Runtime.InteropServices.Marshal.GetFunctionPointerForDelegate(Delegate d)
at TH.Parking.Wrapper.HBCamera.T1800.dll_T18_RegisterStreamReadCallback(STREAM_READ_CALLBACK STREAM_READ_CALLBACK, IntPtr& context)
at TH.Parking.Wrapper.HBCamera.CameraUtilities.StartRecord() in d:\TH.Parking\TH.Parking\Wrapper\HBCamera\CameraUtilities.cs:line 93
I can't find any reason for this error. Can somebody help me to fix this.
I think the callback you pass to create the STREAM_READ_CALLBACK object should be static. Otherwise, the thispointer is lost during the marshalling.
Instead of:
private int StreamReadCallBack(ulong channelHandle, IntPtr context)
{
...
}
try:
private static int StreamReadCallBack(ulong channelHandle, IntPtr context)
{
...
}
And you'll need to somehow put your instance of CameraUtility into the context parameter.