How is dynasm supposed to be setup? - c++

I'm trying to use dynasm. I've found several tutorials online for it, but they all require using weird lines of code such as |.arch x64 that my compiler (MSVC) rejects. There are mentions of an offline Lua parser and .dasc files but none of these tutorials mention how any of this should be setup.
How is dynasm supposed to be setup in a project?

DynASM allows you to write down assembly much easier by mixing C code and ASM code. DynASM files must be preprocessed. The output of compiling a DynASM file (.dasc) is a C file (.c) which you can later integrate in your project.
To preprocess a DynASM file you should use the dynasm program which comes with LuaJIT source code (dynasm/dynasm.lua). The "weird" lines you mentioned are the ASM code that it's processed by DynASM. The asm code is stored as byte values into an array called actions in the resulting C program.
There's a great turorial on DynASM by Josh Haberman: Hello, JIT World: The Joy of Simple JITs. The tutorial includes example code. The code is available as a GitHub repository. Fetch it and start playing with it (note: currently master branch doesn't build, I just sent a pull-request to fix it).
Another good intros to DynASM are:
The Unofficial DynASM documentation (includes tutorials, instruction reference, etc).
DynASM Luapower (DynASM from .lua files).

Related

How can I get the C++ source code of a package on CRAN?

I am interested in the source code of the package https://rdrr.io/cran/fclust/, particularly the functions RI.F and ARI.F, but could only find the R implementations
https://rdrr.io/cran/fclust/src/R/RI.F.R
https://rdrr.io/cran/fclust/src/R/ARI.F.R
which are just link to the C++ code. Where is the source code of the C++ parts of a package usually available? Where in this case?
I am not sure if the package is Open Source to be honest and I am not sure if there is a place where the source code is "usually available".
I explain how to do it for fclust, but instead of just providing a link, I show the path to get there in such a way that it should be reproducible for many other packages at CRAN.
When you go to https://rdrr.io/cran/fclust/ then you see the table entry "Package repository" and behind it a link called "View on CRAN". When you go there and look underneath "Downloads:" you will see a link behind "Package source:". The source code is in the ".tar.gz".
Next, you have to look into the R-code and will see that the function partition_comp is called. You can also see it listed in https://rdrr.io/cran/fclust/f/ as src/partition_comp.cpp. So go into the ".tar.gz"-file and look for that file. It will contain the C++ source code.

how do I create files on sciTE for c++?

I am newly learning c++. I am using the Linux ubuntu operating system and a sciTE text editor.
Do you know how to create a file on scite that I will be able to compile and then create an archive on terminal? also how do I create a 'make file. cpp'. Any help will be greatly appreciated.
Thanks! :)
Do you know how to create a file on scite that I will be able to compile and then create an archive on terminal?
You can use any text editor to write C++ source code. There is nothing very editor-specific about it. The file itself should be assigned a name that your compiler will recognize as designating a C++ source file. Compilers generally look at the filename extension for that purpose, and ".cpp" is a very common pattern recognized as indicating C++ source. It looks like that's what you're intended to use, so when you save the file just be sure to give it a name that ends in .cpp.
In order to successfully compile, you of course need to write valid C++ source code in the file, and in order to compile it to a program (I assume that's what you meant by "archive") it must contain a valid main() function.
how do I create a 'make file. cpp'.
I think you've gotten your instructions confused. Perhaps the instruction is just meant to convey what I already said about giving your source file a name ending in ".cpp". Alternatively, you may have been asked to create a makefile, which is input to the build tool "make", that could be used to build the program instead of running the compiler directly. You may ask specific questions about make here, but we are not in the business of writing full tutorials. The first thing you should do if you need instructions about make would be to consult your course materials and lecture notes, and / or ask your instructor.
On the third hand, make doesn't even need a makefile in some simple cases. It may be that you are instructed to build the program without a makefile. If you have named the source "prog.cpp" and it contains valid C++ source for a complete program, then you should be able to build that program via the command "make prog". In that case, the resulting program will be named "prog".

How to visualize the code flow

I would like to visualize the code flow for a C++ project that I need to modify. The code compiles and runs fine.
Background:
Actually I am modifying an MRI sequence code. The framework is being called idea (SIEMENS). It somehow combines visual studio 2008 and cygwin to call customized command line inputs. Even the strucutre of makefile is different from usual makefile that I usually use for C++ project. (Disclaimer: I do not understand much about makefile and its customization nor do I know much about use of cygwin.)
1) I have access to dll and .so files
2) Also, path to include files are somehow abbreviated.
Abbreviated include statement:
#include "MrServers/MrMeasSrv/SeqIF/csequence.h"
Full include statement
#include "C:/MIDEA/N4_VD13A_LATEST_20120616/n4/pkg/MrServers/MrMeasSrv/SeqIF/csequence.h"
3) My project does not start with main(); but, it starts with init() and then it pass to prep(), check(), run(). Prep stage becomes particularly complicated.
4) The IDEA framework is designed in combination with cygwin for command line use only. So, I can not place break point.
Could someone suggest me how to visualize the code flow?

Using Sphinx-apidoc to generate documentation from C++ code

There have been a couple of threads on this topic in the past that claim Sphinx doesn't support this at all. I had my doubts but either it has been updated since or the documentation for it was quite well hidden, because here is a link on the website stating otherwise:
http://www.sphinx-doc.org/en/master/usage/restructuredtext/domains.html#cpp-domain
Anyway, I'm new to Sphinx but am trying to use it to (eventually) automate documentation using some text from some source C++ code. So far I haven't been able to get anywhere when using the sphinx-apidoc -o ... command. An almost blank document is created. I'm probably not using the right directives, since I don't know how - the supporting documentation hasn't been able to help me.
Can anyone provide some assistance with the basic steps needed to get it working? If it is not possible to auto-generate documentation from C++, what are the C++ domains for and how to use them?
On auto-generating C++ documentation:
After reading up on how to use sphinx at all, you should have a look into breathe:
Breathe provides a bridge between the Sphinx and Doxygen documentation
systems.
It is an easy way to include Doxygen information in a set of
documentation generated by Sphinx. The aim is to produce an autodoc
like support for people who enjoy using Sphinx but work with languages
other than Python. The system relies on the Doxygen’s xml output.
So additionally, you'll need to follow Doxygen commenting style and even setup an doxygen project. But I tried that and it works really well after the initial setup took place. Here is an excerpt of our CMakeLists.txt which might give you an idea on how sphinx and doxygen work together:
macro(add_sphinx_target TARGET_NAME BUILDER COMMENT_STR)
add_custom_target(${TARGET_NAME}
COMMAND sphinx-build -b ${BUILDER} . sphinx/build/${BUILDER}
WORKING_DIRECTORY docs
DEPENDS doxygen
COMMENT ${COMMENT_STR}
)
endmacro(add_sphinx_target)
add_custom_target(doxygen
COMMAND doxygen docs/doxygen.conf
COMMENT "Build doxygen xml files used by sphinx/breathe."
)
add_sphinx_target(docs-html
html
"Build html documentation"
)
So after initial setup, essentially it boils down to:
build doxygen documentation with doxygen path/to/config
cd into the directory where the sphinx configuration is.
build sphinx documentation with sphinx-build . path/to/output
On the c++ domain:
Sphinx is a „little bit“ more than a system to auto-generate documentation. I would suggest you have a look at the examples (and consider that the sphinx website itself is written in sphinx reST code). Especially click the Show Source link on many sphinx-generated pages.
So if you cannot generate documentation automatically for a project, you have to do it yourself. Basically sphinx is a reST to whatever (LaTeX, HTML, …) compiler. So you can write arbitrary text, but the advantage is that it has a lot of commands for documenting source code of different languages. Each language gets its own domain (prefix or namespace) to separate the namespaces of the different languages. So for example I can document a python function using:
.. py:function:: Timer.repeat([repeat=3[, number=1000000]])
Does something nasty with timers in repetition
(source)
I can do the same using the cpp domain:
.. cpp:function:: bool namespaced::theclass::method(int arg1, std::string arg2)
Describes a method with parameters and types.
(source)
So if you want to document your c++ project without doxygen+breathe but with sphinx, you'll have to write the restructured text files yourself. This also means that you split the documentation from your source code, which can be undesirable.
I hope that clears things up a bit. For further reading I strongly suggest that you have a good read on the sphinx tutorial and documentation until you understood what it actually does.

How to avoid symbols and source paths in iOS binary?

When I compile the release version of my iOS app (based on standard Apple supplied iOS app template), look into the resulting executable binary, I see all sorts of symbols and even local cpp source and header paths in there. I'm really stumped why this is (I haven't enabled RTTI*). Especially the source file paths make me feel uncomfortable sending this app across the globe (why should everyone be able to see the directory layout of my development machine?).
Here's are two (randomly picked, moderated) excerpts:
TS/../ACTORS/CActorCanvasCharPart.cpplastMeshcapVerticesOFF BOUNDSupload VERTICES: %d
20CActorCanvasCharPartgrassscrub/Volumes/Data/iOS_projects/code/MyAppName_proj/MyAppName/source/STATES/GAMES/2/CStateGame2_grass.cppbaseShadowmowerstartmowerloopmowermowerCharcutGrassChargrassStuffgrassParticles/Volumes/Data/iOS_projects/code/MyAppName_proj/MyAppName/source/STATES/GAMES/2/CStateGame2_grass.h17CStateGame2_grasssinwriteStroke/Volumes/Data/iOS_projects/code/MyAppName_proj/MyAppName/source/STATES/GAMES/2/CStateGame2_flowers.hflowerBedsandTrailclickstart3inplace2sandDrag/Volumes/Data/iOS_projects/code/MyAppName_proj/MyAppName/source/STATES/GAMES/2/CStateGame
And here are a lot of symbols for self-defined types and structs:
CAssetMgr="_vptr$CMgrBase"^^?"pMain"^{CMain}"inited"B"curveCount"S"curveSpecs"^{CCurveSpec}"gameSpecs"[23{CGameStateSpec="header"{SpecDiskHeader="type"i"version"S}"gameID"C"backgroundColor"{CRGBAcolorf="r"f"g"f"b"f"a"f}"clickPointColor"{CRGBAcolorf="r"f"g"f"b"f"a"f}"clickPointIconColor"{CRGBAcolorf="r"f"g"f"b"f"a"f}"hintColor"{CRGBAcolorf="r"f"g"f"b"f"a"f}}]"currentFont"^{CCharset}"userCharParts"^^{CCharPart}"words"{CDataSet<CName4,CCharArray>="_vptr$CObjectBase"^^?"pMain"^{CMain}"count"i"data"*"dataSize"l}"sets"{CDataSet<CName16,CCharArray>="_vptr$CObjectBase"^^?"pMain"^{CMain}"count"i"data"*"dataSize"l
Can this be avoided, how?
*UPDATE: I just found out that RTTI is on by default. So I cleaned the target, disabled RTTI (GCC_ENABLE_CPP_RTTI = NO) and recompiled. I still see a lot of symbols and source paths in the binary.
UPDATE 2: I checked a few other apps from the app store, and many of them also have their source file paths show up. Pretty scary, if you ask me:
Joined Up Lite
/Users/lloydy/Documents/Development/iPhone/ABC Joined Up/main.m
/Users/lloydy/Documents/Development/iPhone/ABC Joined Up/Classes/SettingsView.m
Crayon Physics
/Users/smproot/Desktop/unzip/CrayonPhysics/v104/Classes/crayon/src/ceng/gameutils/killspriteslowly/killspriteslowly.cpp
/Users/smproot/Desktop/unzip/CrayonPhysics/v104/Classes/crayon/src/ceng/tasks/task/sdl/mixer/ctaskaudiosdlmixer.cpp
Wall Times
/Users/fred/_WORK/ZDNDRP/WallTimes/main.m
/Users/fred/_WORK/ZDNDRP/WallTimes/Classes/SystemCategories.m
Jumbo Calculator
/Users/Christopher/Documents/Development/JumboCalculator 1.0.3/main.m
/Users/Christopher/Documents/Development/JumboCalculator 1.0.3/Classes/CalculatorFaceViewController.m
The file paths are most likely from assert macros which stringify __FILE__ as part of their failure message. iOS's implementation of assert(3) does this, as do the NSAssert macros.
You can remove asserts in release builds by defining NDEBUG (for the C asserts) and NS_BLOCK_ASSERTIONS (for NSAsserts).
In Xcode set Deployment Prostprocessing to Yes in order to trigger Xcode to call the strip command during build process. Then you don't see any source path via nm -a.
However, I still see the source paths of some m files via the strings command :/
What worked for me was setting Generate Debug Symbols to No for release builds. This is under the Apple LLVM 7.0 - Code Generation in Xcode 7.2.
Have ticked the strip debug symbols in the build settings? You can do this (or not) depending on the configuration (build/release). Also you can look into Objective-C Code Obfuscation (which is long winded). From what I gather, you cannot completely remove objective-c information as all method calls are done dynamically, so the library has to have information about your classes/method names in order to function. A useful tip here.
If you have c++ code then you can use the gcc strip utility, although I'm not sure how it like Objetive-C++, if it doesn't you could compile all you cpp into a lib, strip that and link against it in your iOS project.