How to code a script to create a makefile - shell

i'm new year and I need some answer. I searched on the web to some answer but i didn't found anything usefull. What am i searching is for a shell programms that when you execute it, create a Makefile with the binary name in arguments like :
./automakefile.sh hello .
Will build you a Makefile with a binary name called hello.
I hope you guys will help me, i'm counting on you <3

There is, unfortunately, no such magic command. If there was, we wouldn't need Makefiles to start with because the magic would most likely have been incorporated in the compiler.
There are several reasons why there isn't a command like that.
Given a random binary file, you can't generally say what programming language it was written in.
You also can't tell what source file were used to compile the binary file from, or where in the file hierarchy they are located (not just where they were located when the binary file was compiled last time, maybe on another system).
You don't know the dependencies between the source code files. Makefiles are primarily useful for keeping track of these (and compiler flags etc.), so that changing one single source file in a big project does not trigger a recompilation of everything.
You don't know what compiler to use, or what flags to pass to it. This is another thing a Makefile contains.
There are build tools available for making the creation of Makefiles easier, and for making them portable between systems on different architectures (the Makefiles that is, not necessarily the programs, that's down to the programmer). One such set of tool is GNU's autotools, another is CMake, and I'm sure there are others as well, but those are the ones I use.
Now you're facing another but similar problem, and that is that you still need to learn the syntax of, and writ,e your Makefile.am and configure.ac files (for the GNU tools), or your CMakeLists.txt files (for CMake).

Related

How to export/package a group of files from Bazel

This feels too obvious to be unanswered, but if the answer is out there, I haven't found it. For context, I'm incorporating someone else's existing code into a Bazel build, so I'm really not looking for "just don't do it that way"-type answers.
The code produces man dozen related files: Libraries, compiled binaries (from C and C++, if that matters), python and shell scripts, etc. Those files expect to find each other in specific locations (e.g. shell scripts reference binaries by relative or absolute path), and I need to package up and install the whole lot.
Is there a way to do that in Bazel? To pick out a bunch of bazel-generated files (and, in this case, a bunch of input files that we pass through unmodified) and put them in a tarball, or a standard package format (e.g. .deb) or even just place them in the local file system in known locations?
The closest ideas I've seen involve basically doing it by hand (e.g. writing a shell script to go into Bazel's output directory and copy out the files of interest) but that seems easy to get wrong. There has to be a way to use the intelligence of the build system to bundle up a bunch of targets and data files, right?
Naturally, I find what's probably the answer shortly after posting the question: https://docs.bazel.build/versions/master/be/pkg.html. If anyone has further insight, though, I'm definitely happy to hear it!

including makefile while using cmake

need some help with using a 3rd party makefile when building my own project.
There isn't a way to what you want directly. CMake doesn't provide a facility to include files into its generated files. (ie: include a "3rdparty.mk" into a CMake generated Makefile.) Nor can you directly include a "generated-file-type" (ie: a Makefile) into a CMakeLists.txt. CMake's ExternalProject won't let you do that either.
What you need to do is somehow "parse" the makefile that has the information that you desire. There are a myriad of ways that you can do this. For example, you could write a shell-script wrapper that would grep your makefile for what you need then construct a CMake command line with the variables you want defined, and output it or call cmake for you. Depending on how comfortable you are with shell (or perl, python, etc.) you might feel this is the best option.
If you know these values will never (or very rarely change), you can hard code them in to your CMakeLists.txt (not recommended) or into a file you can include() (better).
You could also stay in CMake-land and use CMake's ExternalProject to help you. Using ExternalProject, you can:
Fetch your 3rd party libraries (download, copy, unzip, etc)
Patch the Makefiles of these libraries
Run make on those patched makefiles
Now, this patch that I mentioned is something that you'd have to write yourself, and keep with the source of your primary project. The content of this patch would be a new target for make that would write a file that you could include in your CMakeLists.txt via include(). You could start simply, and have this new make target (eg: make output_variables) write a list of set() commands to lib_A.cmake. After comfortable with that, you could move on to more complicated output; like writing a lib_A-config.cmake file that CMake's find_package() would understand.
Granted, the last option is probably the most complicated but it might make maintenance of your primary project easier, reducing pain in the future. You'll also gain a deeper understanding of CMake.

Make, install, executing a program

I have been a CS student for a while and it seems like I (or many of my friends) never understood what's happening behind the scene when it terms to make, install etc.
Correct me but is make a way to compile a set of files?
what is it mean by "installing a program to a computer" like on windows because when I am coding in different languages such as java or perl, we dont install what we wrote. we would compile (if not, interpret language) and just run it. So, why are programs such as Skype needs to be "installed"?
Can anyone clarify this? I feel like this is something i need to know as a programmer.
Make is a build system
Make is a build system which is simply a way to script the steps needed to compile a program. Make specifically can be used with anything, but is usually used to compile C or C++ programs. It simplifies and creates a standard way for programmers to script the preparation of their program, so that it can be built and installed with ease
Why a build system
You see, if your program is a simple one source file program, then using make might be an overkill, as compiling the simplest c program is as simple as
gcc simpleprogram.c -o simpleprogram.out
However, as the size of the software grows, the complexity of it grows, and the complexity of how it needs to be built grows. For example, you may want to determine which version of each library is installed in the computer which you are compiling in, you may want to run some tests after compiling your program to determine it is working correctly, or you may want to automatically download some dependencies your program has.
Most software built need a mixture of these tasks eventually. So, instead of reinventing the wheel, they use a build system which allow scripting this. If you are familiar with Java (which you mentioned) a build system comparable to make, but used in the java world is Apache Ant.
Why install
Well, lets assume that you used the "make" command but not "make install". The "make" command is usually used to just to prepare the program for compilation, and the compile it. However, once your program is compiled, all you have is an executable in the directory in which you compiled the program in. The program, its documentation, and it's configuration files haven't been put in the appropriate directories needed for all users to use it. That's what "make install" is for. Make install takes all the files associated with the program you just compiled, and puts said files in the appropriate directories, so that it becomes available to everyone, and so that each component is in the expected directory according to your operating system.
make is a bit of software that reduces the amount of code that needs to be compiled - it compares modification times of the source code with the target. If the code has changed a compile is done to construct the target otherwise you can skip that step.
Installing software is placing the executables/configuration files into the right places - perhaps constructing some files along the way. E.g. usernames in your skype example

How to Debug Following Fortran Program

I am trying to compile the following software so that I can step through and debug it. I am only a novice programmer and I am trying to understand how this whole makefile business works with Fortran. I know that there is a ton of literature on makefiles but I just need to insert a simple debug flag and I think if someone provided me with the answer to this question that would be the best way for me to learn.
So the program I am trying to compile, TINKER, is actually made up of several packages, located at http://dasher.wustl.edu/tinkerwiki/index.php/Main_Page. I would like to compile and debug JUST ONE specific executable, "analyze". I contacted the developer and received the following reply but I am still stuck...
Since TINKER has lots of small source code files, what we do is
compile each of the small files to an object file using the "-c" flag.
Then we put all of these object code files (ie, the ".o" files) into
an object library. Finally, we link each of the TINKER top level
programs, such as "analyze", against the object library. There is a
Makefile supplied with TINKER that does this. We also supply
individual scripts called "compile.make", "library.make" and
"link.make" for various CPU/compiler combinations that can be run in
order to perform the steps I describe above. To build a "debuggable"
executable, you just need to include the appropriate debug flags
(usually "-g") as part of the compile and link stages.
I am currently running OSX 10.6.8. If someone could show me which folders I cd into, what commands I enter that would be so great!
Thanks!
My follow up question (once I can figure out how to answer the above via command line will concern how to import the same procedure but using the Photran IDE - http://wiki.eclipse.org/PTP/photran/documentation/photran5#Starting_a_Project_with_a_Hand-Written_Makefile)
The directions are at http://dasher.wustl.edu/tinkerwiki/index.php/Main_Page#Installing_TINKER_on_your_Computer
Maybe out of date? g77 is obsolete -- it would be better to use gfortran.
The key steps: "The first step in building TINKER using the script files is to run the appropriate compile.make script for your operating system and compiler version. Next you must use a library.make script to create an archive of object code modules. Finally, run a link.make script to produce the complete set of TINKER executables. The executables can be renamed and moved to wherever you like by editing and running the ‘‘rename’’ script."
So cd to the directory for the Mac -- based on "we also provide machine-specific directories with three separate shell scripts to compile the source, build an object library, and link binary executables." Then run the command scripts. Probably ./compile.make. Look around for the directories ... you can probably figure it out from the names. Or search for the file "compile.make".
Or find someone local to you who knows more about programming.

How can I include Bash in the cross-compilation of NetBSD using build.sh?

I'm looking for the best practice for including GNU Bash in the cross-compilation of NetBSD using the build.sh script. Right now, my plan is to include it in usr/src/gnu/dist and then create the relevant Makefiles in usr/src/gnu/usr.bin but I was wondering if there was an easier/better way to do this?
The new way is to place files under src/external//. For bash, it's src/external/gpl3/bash. (This directory is called ${EXTTOPDIR.bash} hereafter.)
The original source is expanded into ${EXTTOPDIR}/dist as is. Other files and directories are made at ${EXTTOPDIR}. Start with copying src/external/gpl2/xcvs for example. (BSD) makefiles that are placed (out of the original source) are called "reach-over"; meaning that build procedures are kept without disturbing the original source. This helps to ease maintaining of the original source. (And no, all of these are not documented at all, unfortunately.)
If you need to hook the build as "tools", you'll need something more to care. The procedure is also not documented. Just learn from the source.
If you work on the official NetBSD tree, you have something more to learn about CVS; use vendor branch, etc.
HTH,
Masao

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