Build folder and makefile - c++

The question comes from my puzzlement when compiling a makefile for Deep Learning framework Caffe on Ubuntu, but it relates, I believe, to a more general phenomenon of the nature of compiling a C++ makefile.
After "make all", the resulting files from the compilation were put in a hidden folder: .build_release, not in the respective folders where the cpp files are.
Then when I tried to run the following lines:
./data/mnist/get_mnist.sh
./examples/mnist/create_mnist.sh
I was getting an error that the system does not find the file:
./create_mnist.sh: 16: ./create_mnist.sh: build/examples/mnist/convert_mnist_data.bin: not found
But the file actually existed in the .build_release folder.
What happened and how to fix this problem?

The issue is not with make, you simply need to follow the instructions carefully. The BUILD_DIR is specified by Makefile.config. By default this folder is named build. Once you followed the compilation instructions:
cp Makefile.config.example Makefile.config
# Adjust Makefile.config (for example, if using Anaconda Python)
make all
make test
make runtest
Navigate to build:
cd build
./data/mnist/get_mnist.sh
./examples/mnist/create_mnist.sh

Related

Can someone expand what is meant by 'configure' and 'build' with CMake files

I am downloading this code from GitHub (subdivision-regression), and am getting stuck following the instructions:
To build doosabin_regression:
Run CMake with an out of source build.
Set COMMON_CPP_INCLUDE_DIR to the full path to rstebbing/common/cpp.
Set DOOSABIN_INCLUDE_DIR to the full path to rstebbing/subdivision/cpp/doosabin/include.
Set Ceres_DIR to the directory containing CeresConfig.cmake.
Set GFLAGS_INCLUDE_DIR, GFLAGS_LIBRARY and RAPID_JSON_INCLUDE_DIR. (Add -std=c++11 to CMAKE_CXX_FLAGS if compiling with gcc.)
Configure.
Build.
I have edited the CMakeLists.txt file to put the correct paths in. I then created a new directory called subdivision-regression-bin and ran:
cmake ../subdivision-regression/src
It completes this and displays:
-- Configuring done
-- Generating done
-- Build files have been written to: /home/hert5584/RStebbing/subdivision-regression-bin
However, when I try and run the example code, it cannot find the files listed in CMakeLists.txt (I know they are the right paths as otherwise CMake does not run).
I have tried running:
sudo make install
But get the following error:
make: *** No rule to make target 'install'. Stop.
Any ideas why this isn't working? Have the above steps Configured and Built the files?
The ordered CMake idiom to understand is:
The Configure step
The Generate step (This is often subsumed in the Configure step, and not mentioned explicitly, as in this case.)
The Build step (in which you actually compile/link your code into libraries/executables)
Take a look at this resource for information about the configure and generate stages.
You didn't appear to perform the steps to set CMake cache variables. For these you have to use CMake command line options (-D specifically). So run CMake as something like this instead to set all six variables:
cmake -DCOMMON_CPP_INCLUDE_DIR=/rstebbing/common/cp -DDOOSABIN_INCLUDE_DIR=...[More CMake Cache variables]... ../subdivision-regression/src
For building, try just running make without sudo or install:
make

Compile a single file under CMake project?

I'm developing a C++ project which is going to be enclosed on a bigger one.
I've seen that on the bigger project (is a Qt application and it's being generated from qmake) I am able to compile a single file from the linux command line, just entering the relative path to the specific file as an argument to make.
On the other hand, I'm using CMake for my own project. When I modify some code for a compilation unit and I have to modify its header file, I have to wait a long time to compile its dependencies and then its own source file. But there are some situations in which I would prefer to check whether the source code in the *.cc file is compilable without errors.
Is there a way to generate a Makefile from CMake the way qmake does this? Switching to qmake is not an option anymore.
You do not have to add extra custom targets to your CMake scripts, as the Makefiles generated by CMake already contain .o targets for each .cc file. E.g. if you have a source file called mySourceFile.cc, there will be a Makefile in your build directory that defines a target called <Some Path>/mySourceFile.cc.o. If you cd into your build directory, you can use grep or ack-grep to locate the Makefile that defines this target, then cd into that Makefile's directory and build it.
E.g. suppose the command ack-grep mySourceFile.cc.o prints something like:
foo/bar/Makefile
119:x/y/z/mySourceFile.o: x/y/z/mySourceFile.cc.o
123:x/y/z/mySourceFile.cc.o:
124: # recipe for building target
Then you can build mySourceFile.cc.o by doing:
cd foo/bar && make x/y/z/mySourceFile.cc.o
CMake doesn't have a generic built-in way of doing this (it's an open issue), but if you're using the Ninja generator, you can can use a special Ninja syntax for building just the direct outputs of a given source file. For example, to compile just foo.o you would use:
ninja /path/to/foo.cpp^
Not out-of-the box. CMake does not expose those "internal" makefile rules in the main makefile.
You can do this only if you consider what kind of file structure CMake uses internally. You can e.g. for compiling a single .obj files using CMake generated makefiles call
make -f CMakeFiles/myProg.dir/build.make CMakeFiles/myProg.dir/main.cc.obj
when you have something like
cmake_minimum_required(VERSION 3.1)
project(myProg CXX)
file(WRITE "main.cc" "int main()\n{\nreturn 0;\n}")
add_executable(myProg main.cc)
To build src/foo.cpp alone:
cmake --build . --target src/foo.cpp.o
No, CMake does not offer built-in support to compile single files.
You have to add a target for each object file, maybe by a function iterating over all files of a directory.
Others have suggested ways to find the target name (ending in .cpp.o) from the .cpp filename, but if you already know the name of a target that will trigger compilation of the .cpp file and you're using ninja this suggestion should be easier.
First build the target:
ninja TriggersCppCompilationLib
Assuming your file was changed or was not yet built, ninja will print the full target name. When you see the name come up, hit enter so it is not overwritten. Then simply copy the name from the terminal (e.g. using tmux copy mode).

Why is this happening with cmake

I am working on a c++ project and I am using cmake as the build system, so my workflow here is make changes to code. then,
rm -r build
mkdir build
cd build
cmake -G "Unix Makefiles" ..
make
Now I added glew as a dependency to the project, so whenever I try to run make I get an error saying SDL.h not found(this was working before).After sometime I decided to check CMakeCache.txt.opened it using vim then :wq that's all I did now if I run make, my project is building successfully, I am not sure why this is happening, Can anyone tell me why?
ps: added gif of this event, check it out to get a clear picture
(the code i am working on is linked as well, this exact issue is in this commit "dd4452b45c733e0612bc5f3c632e9d1a08be8072")
link to gif
link to code
variables in cmake are limited to the scope of the directory they are in plus their subdirectories.
This, calling find_module() in the gamelib subdirectory does not find that module for use in the main directory.
The preferred way to propagate include directory dependencies is to add them to the target (in the gamelib directory), like this:
target_include_directories(gamelib BEFORE PRIVATE
$<BUILD_INTERFACE:${SDL2_INCLUDE_DIR}>
$<BUILD_INTERFACE:${GLEW_INCLUDE_DIR}>
)
target_include_directories(gamelib SYSTEM BEFORE PUBLIC
$<BUILD_INTERFACE:${SDL2_INCLUDE_DIR}>
$<BUILD_INTERFACE:${GLEW_INCLUDE_DIR}>
)
then you don't need to even mention them in any executable that uses gamelib.

how to generate glut .so file in Linux

I would like to generate glut .so file in Ubuntu. I've downloaded the files, extracted them and opened the readme. This is the instructions for Linux
MAKEFILE GENERATION TO BUILD GLUT: <-- IMPORTANT!
Use "mkmkfiles.sgi" to put Makefiles using the SGI Makefile conventions
in place. Use "mkmkfiles.imake" to put Makefiles generated from
Imakefiles in place. Run one of these two commands in this directory,
then do a "make".
I don't really understand SGI Makefile. I know Makefile though. Could you please guide me for generating the dll. In the folder, these are the files
adainclude Imakefile mkmkfiles.imake README.fortran README.man
CHANGES include mkmkfiles.sgi README.glut2 README.mesa
FAQ.glut lib mkmkfiles.win README.glut3 README.mui
Glut.cf linux NOTICE README.ibm-shlib README.win
glutdefs Makefile Portability.txt README.inventor README.xinput
glutmake.bat Makefile.sgi progs README.irix6 test
glutwin32.mak Makefile.win README README.irix64bit
IAFA-PACKAGE man README.ada README.linux
I've tried running make but getting errors and there is no CMakeLists. Thank you.
When I run ./mkmkfiles.sgi or mkmkfiles.imake, I get this error
bash: ./mkmkfiles.sgi: /bin/csh: bad interpreter: No such file or directory
Technically you need first to instal tcsh. With that installed, running mkmkfiles.imake will work and generate the required Makefile so you can build on Linux. Here is an old post asking pretty much the same question: http://comments.gmane.org/gmane.linux.lfs.general/17539

Makefile: copy perl/python files from source directory into build directory

I have the following source directory structure
src:
dir1: c++ files, Makefile
dir2: perl/python scripts, Makefile
build:
bin:
binary-executables
bin-subdir: I want my perl/python files to be copied during the build process.
Also, When I do a make install, will the bin-subdir be copied into install/bin by default or I have to specify that as well?
Basically, when you run make X, you are telling Make to find target X in your Makefile. So if you have no install: target, nothing will happen. All of this really depends what is in your Makefiles. If you want to copy your perl/python files into the build directory, one way to do so is to write a Makefile target that runs a *sh command like mv dir2/*.pyc build; mv dir2/*.pl build, and require that target somewhere else in your Makefile. If you need a good Makefile tutorial, here's one that I started with.