Maven is said to employ a form of Convention over Configuration.
I don't want to draw any wrong comparisons but as far as I understand cmake can fill a similar roll for a C++ project as maven can for a Java project.
So, does cmake have some Conventions over Configuration, or is each project configured uniquely? (Wrt. file layout, test layout, build output, etc.)
After experiencing the elegance of Maven 3, I also looked for a convention over configuration C maven style system. ...
I also checked out CMAKE, after creating a skeleton a few things stood out.
CMAKE is sometimes declarative, sometimes procedural, and your always going to end up with an ugly mix. AKA, it's ANT for C without brackets.
CMAKE itself IS portable, alas your project will need platform specifics handled and you better know them in advance. CMAKE modules exist to supposedly help with this, unfortunately their re-usability appears more like the promise of Ansible roles... Theoretically possible, but in practice they end up as decent way for you to organize all that complexity required.
In other words, CMAKE is in no shape or form like Maven. It's more like a lower level ANT, that allows you to use the "Cross-platform" DSL to generate platform specific makefiles.
The one convention that we strongly encourage is to do "out of source" builds, where the build directory contains ALL build products, and is completely separate from the source tree, usually source and build are siblings:
projects
proj1-build-x86
proj1-build-x64
proj1-src
Two primary reasons we always recommend this strategy are (1) to keep the source tree clean of build products, so it is easy to tell what has changed since your last update from your version control system and (2) so that you may have multiple build trees for any given source tree and not worry about the build products and/or settings from one interfering with the other one.
I recently noticed a project I was working on had inadvertently generated some python files in the source tree. I only noticed it, though, when I tried to build both the x86 and x64 builds simultaneously in different build trees... and suddenly the generated python files had some lines duplicated and intermixed. Changed it to generate into the build tree, and all was well.
This is all just part of CMake good practice, though, and is not strongly enforced by anything other than the common sense and discipline of the smart people running these projects...
Related
My question is the following:
Is there a way to tell CMakeFiles where to generate it's makefiles, such as cmake_install.cmake, CMakeCache.txt etc.?
More specifically, is there a way to set some commands in the CMakeFiles that specifies where to output these generated files? I have tried to search around the web to find some answers, and most people say there's no explicit way of doing this, while others say I might be able to, using custom commands. Sadly, I'm not very strong in cmake, so I couldn't figure this out.
I'm currently using the CLion IDE and there you can specifically set the output path through the settings, but for flexibility reasons I would like as much as possible to be done through the CMakeFiles such that compiling from different computers isn't that big of a hassle.
I would also like to avoid explicitly adding additional command line arguments etc.
I hope someone might have an answer for me, thanks in advance!
You can't (easily) do this and you shouldn't try to do it.
The build tree is CMake's territory. It allows you some tiny amount of customization there (for instance you can specify where the final build artifacts will be placed through the *_OUTPUT_DIRECTORY target properties), but it does not give you any direct control over where intermediate files, like object files or internal make scripts used for bookkeeping are being placed.
This is a feature. You have no idea how all the build systems supported by CMake work internally. Maybe you can move that internal file to a different location in your build process, which is based on Unix Makefiles. But maybe that will also horribly break my build process, which is using Visual Studio. The bottom line is: You shouldn't have to care about this. CMake should take care of it, and by taking some freedom away from you, it ensures that it can actually do that job on all supported build toolchains.
But this might still be an unsatisfactory answer to you. You're the developer, shouldn't you be in full control of the results produced by your build? Of course you should, which is why CMake again grants you full control over what goes into the install tree. That is, whatever ends up in the install directory when you call make install (or whatever is the equivalent of installing in your build toolchain) is again under your control.
So you do control everything that matters: The source tree, the install tree, and that tiny portion of the build tree where the final build artifacts go. The rest of the build tree is off-limits for you and for good reasons.
For past 4 years, I have been programming with Eclipse (for Java), and Visual Studio Express (for C#). The IDEs mentioned always seemed to provide every facility a programmer might ask for (related to programming, of course).
Lately I have been hearing about something called "build tools". I heard they're used almost in all kind of real world development. What are they exactly? What problems are they designed to solve? How come I never needed them in past four years? Are they kind of command-line stripped down IDEs?
What are build tools?
Build tools are programs that automate the creation of executable
applications from source code (e.g., .apk for an Android app). Building
incorporates compiling,linking and packaging the code into a usable or
executable form.
Basically build automation is the act of scripting or automating a
wide variety of tasks that software developers do in their day-to-day
activities like:
Downloading dependencies.
Compiling source code into binary code.
Packaging that binary code.
Running tests.
Deployment to production systems.
Why do we use build tools or build automation?
In small projects, developers will often manually invoke the build
process. This is not practical for larger projects, where it is very
hard to keep track of what needs to be built, in what sequence and
what dependencies there are in the building process. Using an
automation tool allows the build process to be more consistent.
Various build tools available(Naming only few):
For java - Ant,Maven,Gradle.
For .NET framework - NAnt
c# - MsBuild.
For further reading you can refer following links:
1.Build automation
2.List of build automation software
Thanks.
Build tools are tools to manage and organize your builds, and are very important in environments where there are many projects, especially if they are inter-connected. They serve to make sure that where various people are working on various projects, they don't break anything. And to make sure that when you make your changes, they don't break anything either.
The reason you have not heard of them before is that you have not been working in a commercial environment before. There is a whole lot of stuff that you have probably not encountered that you will within a commercial environments, especially if you work in software houses.
As others have said, you have been using them, however, you have not had to consider them, because you have probably been working in a different way to the usual commercial way of working.
Build tools are usually run on the command line, either inside an IDE or completely separate from it.
The idea is to separate the work of compiling and packaging your code from creation, debugging, etc.
A build tool can be run on the command or inside an IDE, both triggered by you. They can also be used by continuous integration tools after checking your code out of a repository and onto a clean build machine.
make was an early command tool used in *nix environments for building C/C++.
As a Java developer, the most popular build tools are Ant and Maven. Both can be run in IDEs like IntelliJ or Eclipse or NetBeans. They can also be used by continuous integration tools like Cruise Control or Hudson.
Build tools are generally to transform source code into binaries - it organize source code, set compile flags, manage dependencies... some of them also integrate with running unit test, doing static analysis, a generating documentation.
Eclipse or Visual Studio are also build systems (but more of an IDE), and for visual studio it is the underlying msbuild to parse visual studio project files under the hood.
The origin of all build systems seems like the famous 'make'.
There are build systems for different languages:
C++: make, cmake, premake
Java: ant+ivy, maven, gradle
C#: msbuild
Usually, build systems either using a propriety domain specific language (make, cmake), or xml (ant, maven, msbuild) to specify a build. The current trend is using a real scripting language to write build script, like lua for premake, and groovy for gradle, the advantage of using a scripting is it is much more flexible, and also allows you the to come up with a set of standard APIs(as build DSL).
These are different types of processes by which you can get your builds done.
1. Continuous Integration build: In this mainly developers check-in their code and right after their check-in a build initiates for building of the recent changes so we should know whether the changes done by the developer has worked or not right after the check-in is done. This is preferred for smaller projects or components of the projects. In case where multiple teams are associated with the project or there are a large no. of developers working on the same project this scenario becomes difficult to handle as if there are 'n' no. of check-in’s and the build fails at certain points it becomes highly difficult to trace whether all the breakage has occurred because of one issue or with multiple issues so if the older issues are not addressed properly than it becomes very difficult to trace down the later defects that occurred after that change. The main benefit of these builds is that we get to know whether a particular check-in is successful or not.
2. Gated check-in builds: In this type of check in a build is initiated right after the check in is done keeping the changes in a shelve sets. In this case if the build succeeds than the shelve-set check-in gets committed otherwise it will not be committed to the Team Foundation Server. This gives a slightly better picture from the continuous integration build as only the successful check-in's are allowed to get committed.
3. Nightly builds: This is also referred as Scheduled builds. In this case we schedule the builds to run for a specific time in order to build the changes. All the previous uncommitted changes from the last build are built during this build process. This is practiced when we want to check in multiple times but do not want a build every time we check in our code so we can have a fixed time or period in which we can initiate the build for building of the checked-in code.
The more details about these builds can be found at the below location.
Gated-check in Builds
Continuous Integration Builds
Nightly Builds
Build Process is a Process of compiling your source code for any errors using some build tools and creating builds(which are executable versions of the project). We(mainly developers) do some modifications in the source code and check-in that code for the build process to happen. After the build process it gives two results :
1. Either build PASSES and you get an executable version of your project(Build is ready).
2. It fails and you get certain errors and build is not created.
There are different types of build process like :
1. Nightly Build
2. gated Build
3. Continuous integration build etc.
Build tools help and automates the process of creating builds.
*So in Short Build is a Version of Software in pre-release format used by the Developer or Development team to gain confidence for the final result of their Product by continuously monitoring their Product and solving any issues early during the development process.*
You have been using them - IDE is a build tool. For the command line you can use things like make.
People use command line tools for things like a nightly build - so in the morning with a hangover the programmer has realised that the code that he has been fiddling with with the latest builds of the libraries does not work!
"...it is very hard to keep track of what needs to be built" - Build tools does not help with that all. You need to know what you want to build. (Quoted from Ritesh Gun's answer)
"I heard they're used almost in all kind of real-world development" - For some reason, software developers like to work in large companies. They seem to have more unclear work directives for every individual working there.
"How come I never needed them in past four years". Probably because you are a skilled programmer.
Pseudo, meta. I think build tools do not provide any really real benefit at all. It is just there to add a sense of security arising from bad company practices, lack of direction - bad software architectural leadership leading to bad actual knowledge of the project. You should never have to use build tools(for testing) in your project. To do random testing with a lack of knowledge of the software project does not give any sort of help at all.
You should never ever add something to a project without knowing it's purpose, and how it will work with the other components. Components can be functional separate, but not work together. (This is the responsibility of the software architect I assume).
What if 4-5 components are added into the project. You add a 6th component. Together with the first added component, it might screw up everything. No automatic would help to detect that.
There is no shortcut other than to think think think.
Then there is the auto download from repositories. Why would you ever want to do that? You need to know what you download, what you add to the project. How do you detect changes in versions of the repositories? You need to know. You can't "auto" anything.
What if we were to test bicycles and baby transports blindfolded with a stick and just randomly hit around with it. That seems to be the idea of build tool testing.
I'm sorry there are no shortcut
https://en.wikipedia.org/wiki/Scientific_method
and
https://en.wikipedia.org/wiki/Analysis
There are already some questions about dependency managers here, but it seems to me that they are mostly about build systems, while I am looking for something targeted purely at making dependency tracking and resolution simpler (and I'm not necessarily interested in learning a new build system).
So, typically we have a project and some common code with another project. This common code is organized as a library, so when I want to get the latest code version for a project, I should also go get all the libraries from the source control. To do this, I need a list of dependencies. Then, to build the project I can reuse this list too.
I've looked at Maven and Ivy, but I'm not sure if they would be appropriate for C++, as they look quite heavily java-targeted (even though there might be plugins for C++, I haven't found people recommending them).
I see it as a GUI tool producing some standardized dependency list which can then be parsed by different scripts etc. It would be nice if it could integrate with source control (tag, get a tagged version with dependencies etc), but that's optional.
Would you have any suggestions? Maybe I'm just missing something, and usually it's done some other way with no need for such a tool? Thanks.
You can use Maven in relationship with C++ in two ways. First you can use it for dependency management of components between each other. Second you can use Maven-nar-plugin for creating shared libraries and unit tests in relationship with boost library (my experience). In the end you can create RPM's (maven-rpm-plugin) out of it to have adequate installation medium. Furthermore i have created the installation for CI environment via Maven (RPM's for Hudson, Nexus installation in RPM's).
I'm not sure if you would see an version control system (VCS) as build tool but Mercurial and Git support sub-repositories. In your case a sub-repository would be your dependencies:
Join multiple subrepos into one and preserve history in Mercurial
Multiple git repo in one project
Use your VCS to archive the build results -- needed anyway for maintenance -- and refer to the libs and header files in your build environment.
If you are looking for a reference take a look at https://android.googlesource.com/platform/manifest.
we work under Linux/Eclipse/C++ using Eclipse's "native" C++ projects (.cproject). the system comprises from several C++ projects all kept under svn version control, using integrated subclipse plugin.
we want to have a script that would checkout, compile and package the system, without us needing to drive this process manually from eclipse, as we do now.
I see that there are generated makefile and support files (sources.mk, subdir.mk etc.), scattered around, which are not under version control (probably the subclipse plugin is "clever" enough to exclude them). I guess I can put them under svn and use in the script we need.
however, this feels shaky. have anybody tried it? Are there any issues to expect? Are there recommended ways to achieve what we need?
N.B. I don't believe that an idea of adopting another build system will be accepted nicely, unless it's SUPER-smooth. We are a small company of 4 developers running full-steam ahead, and any additional overhead or learning curve will not appreciated :)
thanks a lot in advance!
I would not recommend putting things that are generated in an external tool into version control. My favorite phrase for this tactic is "version the recipe, not the cake". Instead, you should use a third party tool like your script to manipulate Eclipse appropriately to generate these files from your sources, and then compile them. This avoids the risk of having one of these automatically generated files be out of sync with your root sources.
I'm not sure what your threshold for "super-smooth" is, but you might want to take a look at Maven2, which has a plugin for Eclipse projects to do just this.
I know that this is a big problem (I had exactly the same; in addition: maintaining a build-workspace in svn is a real pain!)
Problems I see:
You will get into problems as soon as somebody adds or changes project settings files but doesn't trigger a new build for all possible platforms! (makefiles aren't updated).
There is no overall make file so you can not easily use the build order of your projects that Eclipse had calculated
BTW: I wrote an Eclipse plugin that builds up a workspace from a given (textual) list of projects and then triggers the build. That's possible but also not an easy task.
Unfortunately I can't post the plugin somewhere because I wrote it for my former employer...
Does anyone have experience using makefiles for Visual Studio C++ builds (under VS 2005) as opposed to using the project/solution setup. For us, the way that the project/solutions work is not intuitive and leads to configuruation explosion when you are trying to tweak builds with specific compile time flags.
Under Unix, it's pretty easy to set up a makefile that has its default options overridden by user settings (or other configuration setting). But doing these types of things seems difficult in Visual Studio.
By way of example, we have a project that needs to get build for 3 different platforms. Each platform might have several configurations (for example debug, release, and several others). One of my goals on a newly formed project is to have a solution that can have all platform build living together, which makes building and testing code changes easier since you aren't having to open 3 different solutions just to test your code. But visual studio will require 3 * (number of base configurations) configurations. i.e. PC Debug, X360 Debug, PS3 Debug, etc.
It seems like a makefile solution is much better here. Wrapped with some basic batchfiles or scripts, it would be easy to keep the configuration explotion to a minimum and only maintain a small set of files for all of the different builds that we have to do.
However, I have no experience with makefiles under visual studio and would like to know if others have experiences or issues that they can share.
Thanks.
(post edited to mention that these are C++ builds)
I've found some benefits to makefiles with large projects, mainly related to unifying the location of the project settings. It's somewhat easier to manage the list of source files, include paths, preprocessor defines and so on, if they're all in a makefile or other build config file. With multiple configurations, adding an include path means you need to make sure you update every config manually through Visual Studio's fiddly project properties, which can get pretty tedious as a project grows in size.
Projects which use a lot of custom build tools can be easier to manage too, such as if you need to compile pixel / vertex shaders, or code in other languages without native VS support.
You'll still need to have various different project configurations however, since you'll need to differentiate the invocation of the build tool for each config (e.g. passing in different command line options to make).
Immediate downsides that spring to mind:
Slower builds: VS isn't particularly quick at invoking external tools, or even working out whether it needs to build a project in the first place.
Awkward inter-project dependencies: It's fiddly to set up so that a dependee causes the base project to build, and fiddlier to make sure that they get built in the right order. I've had some success getting SCons to do this, but it's always a challenge to get working well.
Loss of some useful IDE features: Edit & Continue being the main one!
In short, you'll spend less time managing your project configurations, but more time coaxing Visual Studio to work properly with it.
Visual studio is being built on top of the MSBuild configurations files. You can consider *proj and *sln files as makefiles. They allow you to fully customize build process.
While it's technically possible, it's not a very friendly solution within Visual Studio. It will be fighting you the entire time.
I recommend you take a look at NAnt. It's a very robust build system where you can do basically anything you need to.
Our NAnt script does this on every build:
Migrate the database to the latest version
Generate C# entities off of the database
Compile every project in our "master" solution
Run all unit tests
Run all integration tests
Additionally, our build server leverages this and adds 1 more task, which is generating Sandcastle documentation.
If you don't like XML, you might also take a look at Rake (ruby), Bake/BooBuildSystem (Boo), or Psake (PowerShell)
You can use nant to build the projects individually thus replacing the solution and have 1 coding solution and no build solutions.
1 thing to keep in mind, is that the solution and csproj files from vs 2005 and up are msbuild scripts. So if you get acquainted with msbuild you might be able to wield the existing files, to make vs easier, and to make your deployment easier.
We have a similar set up as the one you are describing. We support at least 3 different platforms, so the we found that using CMake to mange the different Visual Studio solutions. Set up can be a bit painful, but it pretty much boils down to reading the docs and a couple of tutorials. You should be able to do virtually everything you can do by going to the properties of the projects and the solution.
Not sure if you can have all three platforms builds living together in the same solution, but you can use CruiseControl to take care of your builds, and running your testing scripts as often as needed.