Is there the possibility to emit ASM when compiling something using Cranelift? By "ASM" I mean the assembler text-representation, in e.g. Intel-Syntax or similar
Now I was planing on implementing this myself using a dissasembler-library like Capstone or Iced, but then I found Context::set_disasm(bool) which apparently does exactly what I need. The problem is I'm unable to find where to extract this assembler-code from. There's no function like get_disasm as far as I looked.
If it's relevant, I'm building both a JIT and an AOT compiler and I want the dissasembler to work when using either.
Can one help me out?
Retrieve the disasm field of CompiledCode. It is in CompiledCodeBase, so it is not documented, unfortunately.
Related
I would like to use an old msvcr71.dll when compiling Nim.
Is there a way to do so? If yes, how?
This is explained in the manual, right here. As StackOverflow doesn't like link responses, a copy-paste:
proc imported_proc(): ReturnType
{.cdecl, dynlib: "msvcr71.dll", importc.}
This asumes there is a function in msvcf71.dll called imported_proc that you want to wrap in your Nim code without changing the name.
You can also tweak which libraries to load when compiling, as explained here:
$ nim c --dynlibOverride:msvcr71 --passL:msvcr71.dll program.nim
Didn't test any of the code, hope it helps. You can always try to find some code that does this kind of linking, for example https://github.com/khchen/wNim/blob/master/wNim/private/winimx.nim or maybe https://github.com/brentp/hts-nim/blob/master/src/hts/private/hts_concat.nim
I want to implement Control-Flow Integrity in Clang/llvm. (I know there is Forward-Edge CFI already implemented)
My problem is, that I have never implemented anything for a compiler (I am new to compiler based approaches) and therefore don't know where to start.
For my implementation I need first to get a list of all calls (internal => no library calls) and than change how functions are ended (for example: pop + jmp instead of ret).
Does anyone know where to start or even if this is possible using the plugin system (LibClang, Clang Plugins, LibTooling)?
Thanks in advance
here is a advanced one CCFI :
https://bitbucket.org/CCFI/
it based on this :
http://iot.stanford.edu/pubs/mashtizadeh-ccfi-ccs15.pdf
you can learn that how to add your code to each jmp,call,jmp,ret and so on...
I am trying to write source code in one language and have it converted to both native c++ and JS source. Ideally the converted source should be human readable and resemble the original source as best it can. I was hoping haxe could solve this problem for me. So I code in haxescript and have it convert it to its corresponding C++ and JS source. However the examples I'm finding of haxe seems to create the final application for you. So with C++ it will use msbuild (or whatever compiler it finds) and creates the final exe for you from generated C++ code. Does haxe also create the c++ and JS source code for you to view or is it all done internally to haxe and not accessible? If it is accessible then is it possible to remove the building side of haxe so it simply creates the source code and stops?
Thanks
When you generate CPP all the intermediate files are generated and kept wherever you decide to generate your output (the path given using -cpp pathToOutput). The fact that you get an executable is probably because you are using the -main switch. That implies an entry point to your application but that is not really required and you can just pass to the command line a bunch of types that you want to have built in your output.
For JS it is very similar, a single JS file is generated and it only has an entry point if you used -main.
Regarding the other topic, does your Haxe code resembles the generated code the answer is yes, but ... some of the types (like Enum and Abstract) only exist in Haxe so they will generate code that functionally works but it might look quite different. Also Haxe has an always-on optimizer/analyzer that might mungle your code in unexpected ways (the analyzer can be disabled). I still find that it is not that difficult to figure out the Haxe source from the generated code. JS has support for source mapping which is really useful for debugging. So in the end, Haxe doesn't do anything to obfuscate your generated code but also doesn't do much to try to preserve it too strictly.
I am facing a situation of which I have no idea. I am tried to test one method that I have implemented in C++ and I used swig to generate the wrapper. After compilation, when I tried to run the application, I got an error java.lang.UnsatisfiedLinkError.
It further states that
cannot load library:reloc_library[1311]:33
cannot locate '_Z13recognizeFacePKcS0_'
...
and suddenly throw exception.
I tried using adb shell to debug and found library in the right location (data/data/com/mesh/faceAuth/lib/libfaceAuth.so) but it gives the same error. I also read from this site, that it has to do with wrong STL implementation which I don't have any clue of. I will highly appreciate your candid suggestion.
Regards,
Mohammed.
Best guess with what information you have provided, The library you are trying to load needs some dependencies to be loaded before it.
For example:
System.loadLibrary("bullet");
System.loadLibrary("irrlicht");
System.loadLibrary("gamescript");
gamescript library needs other 2 library to be loaded before it. Otherwise, it gives me the same error you have mentioned. I can dig further on this issue if you can post some part of your .mk file for building the library here.
Your error has nothing to do with STL.
You probably reference a global function ::recognizeFace(char const*, char const*) in your code. Maybe, you have another function defined, for example recognizeFace(char*, char*).
I have a game which uses std::wstring as its basic string type in thousand of places as well as doing operations with wchar_t and its functions: wcsicmp() wcslen() vsprintf(), etc.
The problem is wstring is not supported in R5c (latest ndk at the time of this writting).
I can't change the code to use std::string because of internationalization and I would be breaking the game engine which is used by many games ...
Which options do I have?
1 - Replace string and wstring with my own string classes
This would give me better platform independency, but it is ridiculous to reimplement the wheel.
I've already started with a COW implementation of strings. I need it to be COW because I use them as keys in hash_maps.
This is of course lots of work and error prone ... but it seems it is something I can do.
2 - Try to fix the NDK recompiling the STLPort with my own implementations of the wide char string functions of the C standart library (wcslen, mbstowcs ... )
This would be the preferable way ... but I have no idea how to do it :(
How do I replace a function (lets say wcslen) in the libstdc++.a or libstlport_static.a? (not sure where they are :()
And as well I'm not sure which functions I need to reimplement, I know wcslen is not working so I guess they should be all ...
3 - Do you have any other idea?
I can't wait for an official fix for this and I will have to go with option #1 if I can't realize how to do #2.
I've read somewhere that if you target 2.3 you can use wstrings, but I ought to target Android 2.1.
PS: Forgot to say I need to use STL of course, but no RTTI and I can live without exceptions.
Thanks in advance!
Try out CrystaX's NDK. It has had stl support long before the official google one. The current version (r5), which is based off the of the official ndk r5, is still beta 3, but it does have wchar_t support.
http://www.crystax.net/android/ndk-r5.php
I'm suffering from the same problem as you, but my only other thought is to load the strings via the JNI (as jstring* in native land), then convert them to UTF characters as necessary. Take a look at the available JNI string functions here:
http://download.oracle.com/javase/1.5.0/docs/guide/jni/spec/functions.html#string_operations
Qt provides an excellent copy-on-write, international-friendly string implementation, QString, that is LGPLed.
You could, in theory extract it from the Qt source and use it in your own project. You will find the QString implementation in src/corelib/tools/qstring.h and .cpp in a Qt source download. You would also need the QChar, QByteArray, QAtomic, and QNamespace includes/classes (all under the corelib folder,) and you should define QT_NO_STL_WCHAR when compiling. (For this I would compile by hand or using my own script/Makefile.) Not simple, but once you get it up and running your life will be a lot simpler. It's better than reinventing the wheel, because it comes with loads of convenience functions and features.
Rather than stripping out just QString, you could also just use the QtCore module as a whole. See the android-lighthouse project for a Qt port to Android. (Also, it might be better to get your sources from there than from the above "vanilla" link, regardless of what you do.)