Raku NativeCall (LPTSTR) &lpMsgBuf? - raku

Raku/Perl6
Windows
In Raku's Native Call
https://docs.raku.org/language/nativecall
What do you use for C's (LPTSTR) &lpMsgBuf in the sub declaration? Is that a pointer to a pointer?
Many thanks,
-T
Edit: To remove any misunderstanding, I am not asking about how to write something in "C" or "C++". Raku is what Perl 6 is now called. And NativeCall is a Raku module (not C) that interfaces with System calls, such as Kernel32.dll.
My question is in Raku / Perl 6, how do I represent a (LPTSTR) &lpMsgBuf on the Raku sub declaration line.
If it helps, (LPTSTR) &lpMsgBuf is C++ syntax and is represented as LPTSTR in Kernel32.dll's call.

Figured it out. It is "CArray[byte] is rw"

Related

what is $(-*-command-variables-*-)) in gnu make

In my project makefile, there is a variable named "--command-variables--". I could guess its meaning from the context, but I want to know more about "--command-variables--". No result from google and GNU make manual.
Here is my test makefile,
all:
$(warning $(-*-command-variables-*-))
#$(warning $(.VARIABLES))
#$(foreach v, $(.VARIABLES), $(info $v===>$($v)))
When I type make test=Makefile, it prints out:
Makefile:2: test=Makefile
make: `all' is up to date.
I found this variables is in .VARIABLES variable, but I can not find it in GNU manual.
The version of make I used is GNU make 3.81.
Can anyone tell me where does this variables defined in or more about these variables? Thank you.
It's one internal variable defined in main.c (line 1344),
/* Define an unchangeable variable with a name that no POSIX.2
makefile could validly use for its own variable. */
(void) define_variable ("-*-command-variables-*-", 23,value, o_automatic, 0);

Accessing files using MPI

THIS WORKED (see comment in the code)
I am new to MPI and still learning it. I am actually trying to write a code in Fortran to read data from same set of files (already generated) on each processor at same time and perform different computations in different processors. For which I decided to use,
program...
use mpi
implicit none
.
.
.
call mpi_file_open(mpi_comm_world,filename_i,mpi_mode_rdonly,mpi_info_null,i,ierr)
to start with the program. Now, each processor calls a subroutine in which I am trying to use normal fortran command to open files, open(i,*)...(since I don't use mpi in subroutine).
First, I am not confident about this idea itself. Next, it gives this error,
_open(mpi_comm_world,filename_i,mpi_mode_rdonly,mpi_status_ignore,i,ierr) (1)
Error: There is no specific subroutine for the generic 'mpi_file_open'
at (1)
Please give your suggestions and comments.
The thing I am trying to do is very long because of subroutine, I would just include a prototype code, if this is solved, my problem will be solved. The code below gives the same error as said before. Please give your suggestions. Thanks.
program hello
use mpi
integer::ierr,num_procs,my_id,i,j,no
call MPI_INIT(ierr)
call MPI_COMM_RANK (MPI_COMM_WORLD,my_id,ierr)
call MPI_COMM_SIZE (MPI_COMM_WORLD,num_size,ierr)
open(4,file='hella') !CHANGING THIS LINE
do i=1,num_size
if(i-1 .eq. my_id)print*,"In",my_id
if(i-1 .eq. my_id)then
read(4,*)no
print*,no
endif
enddo
call mpi_finalize(ierr)
end program hello

Get script name in OCaml?

Does OCaml have a way to get the current file/module/script name? Something like:
C/C++'s argv[0]
Python's sys.argv[0]
Perl/Ruby's $0
Erlang's ?FILE
C#'s ProgramName.Environment.CommandLine
Factor's scriptname/script
Go's os.Args[0]
Haskell's System/getProgName
Java's System.getProperty("sun.java.command").split(" ")[0]
Node.js's __filename
etc.
I don't know anything about OCaml but some googling turned up
Sys.argv.(0)
See http://caml.inria.fr/pub/docs/manual-ocaml/manual003.html#toc12
I presume you are scripting in OCaml. Then Sys.argv.(0) is the easiest way to get the script name. Sys module also provides Sys.executable_name, but its semantics is slightly different:
let _ = prerr_endline Sys.executable_name; Array.iter prerr_endline Sys.argv;;
If I run the above line, putting the line in test.ml, by ocaml test.ml hello world, I have:
/usr/local/bin/ocaml - executable_name
test.ml - argv.(0)
hello - argv.(1)
world - argv.(2)
So OCaml toplevel does something fancy against argv for you.
In general, obtaining the current module name in OCaml is not easy, from several reasons:
ML modules are so flexible that they can be aliased, included into other modules, and applied to module functors.
OCaml does not embed the module name into its object file.
One probably possible workaround is to add a variable for the module name by yourself, like:
let ml_source_name = "foobar.ml"
This definition can be probably auto inserted by some pre-processing. However, I am not sure CamlP4 can have the file name of the currently processing source file.
If your main purpose is simple scripting, then of course this pre-processing is too complicated, I am afraid.
let _ =
let program = Sys.argv.(0) in
print_endline ("Program: " ^ program)
And posted to RosettaCode.
In OCaml >= 4.02.0, you can also use __FILE__ to get the filename of the current file, which is similar to Node's __filename and not the same as Sys.argv.(0).

gfortran, DLL, underscore

I want to access some subroutines from a third party DLL. The functions use STDCALL as the calling convention.
Running dumpbin /export foo.dll gives me something like:
...
7 6 00004B40 Foo#16
...
I compile my code using:
gfortran test.f90 -o test.exe -Wl,foo.dll
I get an error: undefined reference to '_foo_' (note the underscores).
I have tried adding the -mrtd compilation flag, as well as other flags I googled, all to no avail.
How can I tell fortran to not add the underscores?
edit: A bit of clarification is in order.
I have an existing DLL to which I do not have the source to.
This DLL is written in Visual Basic, if it helps.
I want to call this DLL from fortran.
When I write in test.f90: Foo(1.0d0) I get an undefined reference to '_foo_' linkage error
Did you try -fno-underscoring ?
I found a post by Tobias Burnus (a gfortran developer) at http://www.rhinocerus.net/forum/lang-fortran/604847-fortran-dll-call-excel-2.html (near the end) -- he recommends the use of compiler directives instead of -mrtd.
You need to combine the use of ISO_C_BINDING with compiler attributes. You should really read the Mixed-Language Programming section of the gfortran manual. It gives good advice that can be used with other compilers as well. In particular, in your case you need the stdcall attribute:
interface VisBasSubs
subroutine foo (DoubleArg) bind (C, name="Foo")
!GCC$ ATTRIBUTES stdcall :: foo
use iso_c_binding, only: c_double
real (kind=c_double), intent (inout) :: DoubleArg
end subroutine foo
end interface VisBasSubs
Notice the line with stdcall, it's what should make it work.
Just wanted to expand on M.S.B's -fno-underscoring answer: You may run into issues if using f2c & g77. From the gfortran documentation:
With -funderscoring in effect, GNU
Fortran appends one underscore to
external names with no underscores.
This is done to ensure compatibility
with code produced by many UNIX
Fortran compilers.
Caution: The default behavior of GNU
Fortran is incompatible with f2c and
g77, please use the -ff2c option if
you want object files compiled with
GNU Fortran to be compatible with
object code created with these tools.
Use of -fno-underscoring is not
recommended unless you are
experimenting with issues such as
integration of GNU Fortran into
existing system environments
(vis-à-vis existing libraries, tools,
and so on).
You might need to recompile the DLL with something like -fno-underscoring to remove the underscores from the DLL.
I've run into portability issues related to underscore prefix/suffix by certain Fortran compilers: Some compilers _prefix or suffix_ by default, while others don't! My solution has been preprocessor directives:
#ifdef LC_UNSC
#define GET_DIP_MOMENT get_dip_moment_
#elif LC_NOUNSC
#define GET_DIP_MOMENT get_dip_moment
#endif
...
call GET_DIP_MOMENT()
A different approach is to use the ISO C Binding of Fortran 2003, which is supported by gfortran >= 4.3. This will automatically use the underscoring conventions of C (i.e., probably none), rather those of the Fortran compiler. It will also give you control over the case (capitalization) of the subroutine names, if the Windows linker cares about that. Fortran is case insensitive, and so you can call Fortran subroutines by any case -- probably the linker is converting to lower case.
Including the following "interface" in the declarations of the Fortran routine that calls "Foo" describes Foo to be a C subroutine (void function) with a single argument of double type -- Fortran input/output, or a pointer in C. If Foo has other properties, the interface needs to be changed. The "bind" clause specifies the case-sensitive name to provide to the linker. If you call Foo from several Fortran routines, then it is best to put the interface into a module and "use" it from each Fortran routine.
This is intended for C -- maybe it will work for Visual Basic. The ISO C Binding gives a lot of control, so if this doesn't work, maybe some variation will.
interface VisBasSubs
subroutine foo (DoubleArg) bind (C, name="Foo")
use iso_c_binding, only: c_double
real (kind=c_double), intent (inout) :: DoubleArg
end subroutine foo
end interface VisBasSubs

Objective-C Code Obfuscation

Is there any way to obfuscate Objective-C Code ?
Thanks
The selectors are still plaintext - otool -o will dump out all your objects and the methods they define. You can also dump out all internal and external selectors accessed in the code with a one-liner that follows. Obfuscating method and parameter names at the source level would probably be easiest, though doing it at the object level will also obfuscate in a language-independent way at the expense of some linker table manipulation.
otool -s __TEXT __objc_methname yourapp.app/executable_file |expand -8 | cut -c17- | sed -n '3,$p' | perl -n -e 'print join("\n",split(/\x00/,scalar reverse (reverse unpack("(a4)*",pack("(H8)*",split(/\s/,$_))))))'|less
Objective c is a straight superset of C, therefore all normal C obfuscation techniques work. If you want to work with cocoa, however, you're going to have a bit of an obstacle because the method names are fairly self-documenting.
For your own methods, you just have to self-document the methods incorrectly. e.g.
-(void) doSomethingInnocent:(BOOL)animated withObject:passwords;
when you would normally have written:
-(void) sendObjectToMyServer:(BOOL)coverupAnimation;