I have a program which performs a useful task. Now I want to produce the plain-text source code when the compiled executable runs, in addition to performing the original task. This is not a quine, but is probably related.
This capability would be useful in general, but my specific program is written in Fortran 90 and uses Mako Templates. When compiled it has access to the original source code files, but I want to be able to ensure that the source exists when a user runs the executable.
Is this possible to accomplish?
Here is an example of a simple Fortran 90 which does a simple task.
program exampl
implicit none
write(*,*) 'this is my useful output'
end program exampl
Can this program be modified such that it performs the same task (outputs a string when compiled) and outputs a Fortran 90 text file containing the source?
Thanks in advance
It's been so long since I have touched Fortran (and I've never dealt with Fortran 90) that I'm not certain but I see a basic approach that should work so long as the language supports string literals in the code.
Include your entire program inside itself in a block of literals. Obviously you can't include the literals within this, instead you need some sort of token that tells your program to include the block of literals.
Obviously this means you have two copies of the source, one inside the other. As this is ugly I wouldn't do it that way, but rather store your source with the include_me token in it and run it through a program that builds the nested files before you compile it. Note that this program will share a decent amount of code with the routine that recreates the code from the block of literals. If you're going to go this route I would also make the program spit out the source for this program so whoever is trying to modify the files doesn't need to deal with the two copies.
My original program (see question) is edited: add an include statement
Call this file "exampl.f90"
program exampl
implicit none
write(*,*) "this is my useful output"
open(unit=2,file="exampl_out.f90")
include "exampl_source.f90"
close(2)
end program exampl
Then another program (written in Python in this case) reads that source
import os
f=open('exampl.f90') # read in exampl.f90
g=open('exampl_source.f90','w') # and replace each line with write(*,*) 'line'
for line in f:
#print 'write(2,*) \''+line.rstrip()+'\'\n',
g.write('write(2,*) \''+line.rstrip()+'\'\n')
f.close
g.close
# then complie exampl.f90 (which includes exampl_source.f90)
os.system('gfortran exampl.f90')
os.system('/bin/rm exampl_source.f90')
Running this python script produces an executable. When the executable is run, it performs the original task AND prints the source code.
Related
What options do Bazel provide for creating new or extending existing targets that call C/C++-code checkers such as
qac
cppcheck
iwyu
?
Do I need to use a genrule or is there some other target rule for that?
Is https://bazel.build/versions/master/docs/be/extra-actions.html my only viable choice here?
In security critical software industries, such as aviation and automotive, it's very common to use the results of these calls to collect so called "metric reports".
In these cases, calls to such linters must have outputs that are further processed by the build actions of these metric report collectors. In such cases, I cannot find a useful way of reusing Bazel's "extra-actions". Ideas any one?
I've written something which uses extra actions to generate a compile_commands.json file used by clang-tidy and other tools, and I'd like to do the same kind of thing for iwyu when I get around to it. I haven't used those other tools, but I assume they fit the same pattern too.
The basic idea is to run an extra action which generates some output for each file (aka C/C++ compilation command), and then find all the output files afterwards (outside of Bazel) and aggregate them. A reasonably complete example is here for reference. Basically, the action listener (written in Python) decodes the extra action proto and extracts the source files, compiler options, etc:
action = extra_actions_base_pb2.ExtraActionInfo()
with open(argv[1], 'rb') as f:
action.MergeFromString(f.read())
cpp_compile_info = action.Extensions[extra_actions_base_pb2.CppCompileInfo.cpp_compile_info]
compiler = cpp_compile_info.tool
options = ' '.join(cpp_compile_info.compiler_option)
source = cpp_compile_info.source_file
output = cpp_compile_info.output_file
print('%s %s -c %s -o %s' % (compiler, options, source, output))
If you give the extra action an output template, then it can write that output to a file. If you give the output files distinctive names, you can find them all in the output tree and merge them together however you want.
A more sophisticated option is to use bazel query --output=proto and write code to calculate the extra action output filenames of the targets you're interested in from there. That requires writing more code, but you don't have problems with old output files in the output tree that are accidentally included when aggregating.
FWIW, Aspects are another possibility. However, I think extra actions work acceptably for this.
I've written an octave script, hello.m, which calls subfunc.m, and which takes a single input file, a command line argument, data.txt, which it loads with load(argv(){1}).
If I put all three files in the same directory, and call it like
./hello.m data.txt
then all is well.
But if I've got another data.txt in another directory, and I want to run my script on it, and I call
../helloscript/hello.m data.txt
this fails because hello.m can't find subfunc.m.
If I call
octave --path "../helloscript" ../helloscript/hello.m data.txt
then that seems to work fine.
The problem is that if I don't have a data.txt in the directory, then the script will pick up any data.txt that is lying around in ../helloscript.
This seems a bit fragile. Is there any way to tell octave, preferably in the script itself, to get subfunctions from the same directory as the script, but to get everything else relative to the current directory.
The best robust solution I can think of at the moment is to inline the subfunction in the script, which is a bit nasty.
Is there a good way to do this, or is it just a thorny problem that will cause occasional hard to find problems and can't be avoided?
Is this in fact just a general problem with scripting languages that I've just never noticed before? How does e.g. python deal with it?
It seems like there should be some sort of library-load-path that can be set without altering the data-load-path.
Adding all your subfunctions to your program file is not nasty at all. Why would you think so? It is perfectly normal to have function definitions in your script. The only language I know that does not do this is Matlab but that's just braindead.
The other alternative you have is to check that the input file argument, data.txt exists. Like so:
fpath = argv (){1};
[info, err, msg] = stat (fpath);
if (err)
error ("could not stat `%s' : %s", fpath, msg);
endif
## continue your script knowing the file exists
But really, I would recommend you to use both. Add your subfunctions in your main program, the only reason to have it on separate file is if you plan on sharing with other programs, and always check input arguments.
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
To run a CUDA C program we build the program and then run the binary file created from the command line as
/.prgm_bin_file
If for example the program needs some input files like for programs to image processing, I want to supply the data files or the input files at the time of compilation.
How can I do that. How the above command can be edited to give the required files.
Thanks in advance.
If your program opens data files to use for input, it's using some file I/O API to do so. For example, one possible method is to use fopen.
Just to use it as an example, if you are using fopen, it expects a filename (a character string) passed as the first parameter.
Many programs will take this filename from a the command line used to invoke the program. But there's nothing that would prevent you from hard-coding the filename:
fp=fopen("mydata", "r");
In that case, the program would always attempt to open the file mydata
But if your program is already designed to use the filename as a command line parameter, it's not clear that this is any more useful than just invoking your program that way:
./prgm_bin_file mydata
I hope the title clarifies what I want to ask because it is a bit tricky.
I have a SCONS SConscript for every subdir as follows (doing it in linux, if it matters):
src_dir
compiler
SConscript
yacc srcs
scripts
legacy_script
data
SConscript
data files for the yacc
I use a variant_dir without copy, for example:
SConscript('src_dir/compiler/SConscript', variant_dir = 'obj_dir', duplicate = 0)
The resulting obj_dir after building the yacc is:
obj_dir
compiler
compiler_compiler.exe
Now here is the deal.
I have another SConscript in the data dir that needs to do 2 things:
1. compile the data with the yacc compiled compiler
2. Take the output of the compiler and run it with the legacy_script I can't change
(the legacy_script, takes the output of the compiled data and build some h files for another software to depend on)
number 1 is acheived easily:
linux_env.Command('[output1, output2]', 'data/data_files','compiler_compiler.exe data_files output1 output2')
my problem is number 2: How do I make the script runner depend on outputs of another target
And just to clarify it, I need to make SCONS run (and only if compiler_output changes):
src_dir/script/legacy_script obj_dir/data/compiler_output obj_dir/some_dir/script_output
(the script is usage is: legacy_script input_file output_file)
I hope I made myself clear, feel free to ask some more questions...
I've had a similar problem recently when I needed to compile Cheetah Templates first, which were then used from another Builder to generate HTML files from different sources.
If you define the build output of the first builder as source for the second builder, SCons will run them in the correct order and only if intermediate files have changed.
Wolfgang