Make itself does not compile the source files. The Makefile (input for make) contains a set of targets. Each target has a set of dependencies (on other targets) and rules how to build the target. Make reads the Makefile(s) and manages all targets, dependencies, and build rules.
Examples of built-in implicit rules that use CPPFLAGS
In the former Makefile, a is not evaluated until it’s used elsewhere in the Makefile, while in the latter a is evaluated immediately even though it’s not used. This is an old question but this example helps me understand the difference whenever I forget. On Windows 10 or Windows 11, you can run the command winget install ezwinports.make in the command line or PowerShell to quickly install it, restart the command line or PowerShell. An outdated alternative was MinGW, but the project seems to be abandoned, so it’s better to go for one of the previous choices. Find centralized, trusted content and collaborate around the technologies you use most.
Simple assignment :=
If it’s from Linux, you might need to use a real Linux or WSL. If make can run parallel builds, it will launch up to 6 simultaneous compilation process (e.g. 6 calls to gcc). The -j option is only use to speed up application build, it determines how many jobs make can spawn for the build.
Since a thread that does disk operations is technically almost idle from CPU point of view, add one to the total number of cores. As you say the -j flag tells make that it is allowed to spawn the provided amount of ‘threads’. Ideally each thread is executed on its own core/CPU, so your multi-core/CPU environment is used to its fullest. Can I pass variables to a GNU Makefile as command line arguments? In other words, I want to pass some arguments which will eventually become variables in the Makefile. So in order to attack the problem, the error message from gcc is required.
The idea behind this is that all cores have their own thread and there is one additional managing thread that handles the targets and which is next to be built. If you set the allowed number of threads too high, it is plinko casino not possible to schedule each thread on its own core. Additional scheduling (context) switches are required to let all threads execute. This additional resource usage obviously result in lower performance.
You can either set -j or even higher -j so that compilation can happen in parallel. All relative paths in the makefile will be relative to your current directory and not the directory of the makefile. I’m following the instructions of someone whose repository I cloned to my machine. I want to use the make command as part of setting up the code environment, but I’m using Windows. Connect and share knowledge within a single location that is structured and easy to search.
An alternative is installing make via Chocolatey (as pointed out by Vasantha Ganesh K). However, number of cores+a few is typically a good approximation. The only way to know for sure is experimentation. It may behoove you to read some of the comments before taking action. The usual “opposite” of gmake is BSD make, which will tend to be make on BSD systems, unsurprisingly. If you want to see what BSD make is like, on Debian derivatives it’s available as apt-get install pmake.
With that flag you can execute a makefile with a name other than makefile. Because you do want to override your Makefile’s CFLAGS, and not just the environment (which has a lower priority with regard to Makefile variables). You can also create a symbolic link from “make” to “mingw32-make”, or copying and changing the name of the file. I would not recommend the options before; they will work until you do changes on the MinGW installation. Note that you might not be able to select your environment.
Then in your makefile you can refer to $(foo). Note that this won’t propagate to sub-makes automatically. To add or update packages, just run the setup again and select the desired package versions. In my case there was a static variable which was not initialized. I don’t know the logic behind it but worked for me.
