I want to evaluate the performance of Rascal for a given rewrite system that I've written. I'm wondering if there's a good way of doing it?
Ideally, I'd generate some compiled Java classes from the system and then run them manually against my inputs. Is there an easy or recommended way to do it?
Cheers,
One way to do this is to use the functions in the library util::Benchmark. Typically, you could write something like
cpuType( (){ call_the_function_I_want_to_observe(); } ). This will execute your function and print the cpu time used.
Note that Rascal can be executed in two ways: interpreted and compiled which makes a big difference when measuring performance. We are working hard at the moment to fully integrate the compiler in the Eclipse IDE, but a stand alone version is available as well. This can be called as java -Xss8m -jar rascal-0.8.4-SNAPSHOT.jar --compiledREPL followed by at least values for directories for sources (--src), and binaries (--bin). Here rascal-0.8.4-SNAPSHOT.jar (but most likely named differently) is downloaded from the https://update.rascal-mpl.org/console/rascal-shell-unstable.jar.
If you need more information, don't hesitate to ask for more details: this part of our tool chain is unfortunately still undocumented.
Related
I have downloaded the sources, then... I don't know what I'm supposed to do.
I think that we have to compile these, but I'm not really familiar with java.
Do you have a complete example for use it ?
The java2dart tool was written for Google's own use, to help convert many of the tools from Java into Dart. Is was not intended to support conversion of all Java apps; just what was required to get things like the IDE tools (Analyzer, etc.) into Dart.
As such, there's not a huge amount of info on what it can/can't do or the best way to use it. It is written in Java, and there doesn't appear to be a pre-built binary; so it would almost certainly involve compiling the Java yourself. Unfortunately I have almost zero experience with Java (or fortunately, depending on your point of view :))
You can find a little info on this in the Dart Google Group here:
https://groups.google.com/a/dartlang.org/d/msg/misc/4mSK-M7dm2U/ARbTh6emb-sJ
I wonder whether anyone has tried running java2dart on java2dart to get a nice Dart version? :) Or even then running it through dart2js to get a JavaScript version! ;)
In this article it says: "The Dart VM reads and executes source code, which means there is no compile step between edit and run.". Does that mean that you can exchange source-code on the fly in a running Dart system like in Erlang? Maybe the compiler is removed from the runtime system and then this is no longer possible. So that's why I'm asking.
Dart is run "natively" only in Dartium, which is a flavour of Chrome with DartVM. When you develop an application you still need to compile it it to JavaScript. This way you get fast development lifecycle and in the end you can compile code to JS. Because it's compiled code there is lots more room for compiler to run optimisations on the code. So from my perspective, the compiler is still there and I don't think you would be able to replace code at runtime.
You can send around source code and run it, but it would need to be in a separate isolate. Isolates do have some relationship to Erlang concepts.
The Dart VM doesn't support hot swapping (Called live edit in V8). However, based on mailing list discussions, it sounds like this is something that the authors do want to support in the future.
However, as the others have mentioned, it is possible to dynamically load code into another isolate.
George "Mirage" Bakhtadze, the author of Cast II engine, has wrote about an include-based technique which can be used to create generic containers and algorithms. The source is avaiable from the repo at Github. For me, his include-based technique is very interesting and useful, because it can be used for older Delphi and it is compatible between Delphi and Free Pascal (and non-Windows OS ready).
It would be more useful for me if the _GenVector written in "gen_coll_vector.inc" has Sorted & Duplicates properties and related behaviors (behaving the same way as in TStringList).
However, it is less obvious for me to insert the code when there are many include directives (I wonder how George managed this in the first place). Therefore, I wonder whether it is possible to obtain a sample file with all include files explicitly included ? It might be more straightforward for me to start from there.
I mean that there is certain built-in pre-processor that works before the actual compiling and whether there is a way to keep these intermediate files ?
Delphi does not use a pre-processor. It is (and always has been, since Turbo Pascal days) a single-pass compiler. There is no intermediate step. When you {$I} to include files, they are inserted in place in memory during the compilation process. Therefore, there is no "intermediate file" that can be kept.
tldr; at bottom.
Ok, so once again an interesting problem and I'm looking for a fun and interesting solution.
My current project involves being very modular, meaning the program functionality will be easily changed based on different modules and the program would adapt.
So I started out with the typical route, which is using DLL plugins. Now this is just way to normal, I want to think outside the box a bit.
The modules included in my program are long running campaigns that may take weeks to finish, and there will be many running at a time. So stability is a big issue, so I thought about what Google Chrome does. Processes, not DLLs or threads.
So I have a framework going and I need a way to get some information about each module (which are now EXEs). Now for my DLL framework I was exporting a "Register" function that would fill in some information.
So I thought to myself, hey EXEs can export functions, let's see if that actually works...It doesn't. I did some research into how Windows handles theses things and I don't feel like hacking the PE headers on the fly (but it's the out of the box kind of thinking I'm going for).
I'm planning on using named pipes and CLI parameters to transfer data between the main program and the module exe's. I could use that in a register fashion, but I want to here other peoples thoughts.
tldr: I'm using EXE's instead of DLL's for plugins. Looking for a way to easily export one time information like a exported "Register" function would on a DLL. Thoughts?
You might still consider having the modules written as DLLs with defined entrypoints (e.g., the Register function). Then you write the executable that loads the specified DLL. Your main application would fire off the driver executable and give it a name of a plugin DLL.
That way it is still easy to define and export the set of APIs that must be provided yet still run it as a separate process. The one executable that you write can load the specified DLL and then handle the necessary IPC with the main app.
You could define a protocol via the stdin/stdout, named pipes, sockets, etc.
I have successfully used 'plain' COM for several projects, and objects inheriting from TAutoObject. The bonusses here are IDL; the interopability with .Net, VBA and other non-Delphi things; and the fact that implementors still can choose wether to supply a DLL, an exe, an NT-service, and optionally run hosted over the network (COM+/DCOM). There may be several considerations you should handle about multi-threading and locking, but I found all that I needed to know online.
You can, of course, not use symbols exported by a (running) exe since it is running in another boundary. But, you can load an exe as an image (as you would do with a library) using LoadLibrary(Ex) and then, use the functions exported by the exe. I have tested (just for fun) when debugging PeStudio. See the snapshot below of chrome.exe loaded in the process space of PeStudio.exe using LoadLibrary.
I have been asked to update a program written in 1987 in Delphi (I guess). I have no documentation about this program only a few side notes the programmer took that don't make too much sense to make.
The cd show this files:
Size | Filename
19956 VP.DTA
142300 VP.LEX
404 VP.NDX
126502 VP.RCS
131016 VP.SCR
150067 VP.XEL
101791 vp.exe
Is anyone of this files a database? If so can I access it's data?
I tried several code decompilers but they show a message saying it was not a Win32 compatible application.
The program run in MS-DOS.
Is it possible to obtain the source code? Can I use this code in any way to build a new application?
Update01: I can run the program in MS-DOS. The program conjugate verbs and shows an example sentence where the verb can be used. The GUI is a little bit confusing and there is no help menu so I can't see all the capabilities of the program.
Update02: In conversation with the owner of the program we found another solution. He ask me if it was possible to have the program in a server and the clients could login in with a user and a password and execute the program in a terminal. I have an account in my university server, which I can access throughout ssh and compile and execute c programs in it. The server is in linux so I couldn't try the program in it. If I set up a windows server, can I have multiple people accessing and executing the program in a terminal? The program is an exe. Doesn't this raise some security issues?
Delphi is from mid nineties, so that probably means Delphi's ancestor Turbo Pascal, not Delphi.
Some extensions sound familiar, as shortened versions of words:
ndx = index
dta = data
scr = screen (?)
lex = lexicon (list of words or deduped strings in general) (?)
Screen was sometimes used for e.g. helpscreens, a medieval form of helpfiles, they are typicall ansi screens that can be loaded directly into screen memory
There is a fair chance that this is something handcrafted, specially if that date of 1987 and the general assumption "pascal" is true, and not generated by some known database package at all.
Reverseengineering the fileformat might be a more worthwhile way than trying to reverseengineering the app.
A good start would to be to take a the unix "file" command to see if it can recognize the file types. (the file command searches for signatures inside files, and there are windows ports. I use Cygwin's)
A devel experienced in such matters can also see a lot from a hexdump (specially the first parts of a file)
Is it possible to obtain the source code?
Probably not, you may want to look at something like IDA Pro which can disassemble applications to C using something like Hex-Rays.
Do you know what the application is supposed to be?
If it's ms-dos, you're probably better off just drawing up new requirements and doing new development.
Look for DeDe to reverse engineering a delphi compiled program. But as far as i know, delphi is a real compiler. So there is no way to de-compiled it. If you are able to read assembler code then you can try de-compile it. Clipper and Foxpro (dos version) are another stories cause they not real compiler.
This is definitely not Delphi. It might be one of the database centric languages like Clipper 1. .SCR probably means "screen" and defines I/O masks. .NDX is a table index and .DTA means "data".
If it is clipper, you might actually be lucky, because as far as I remember these programs were P code, so it could be possible to decompile it.
It looks like CLipper (NDX and SCR). If you have a DBF file then it's Clipper for sure. But some people renamed the DBF to something like DAT. If it is Clipper, I believe there was a decompile named Valkyrie.