Content
Variables in make can come from the environment in which make is run. Every environment variable that make sees when it starts up is transformed into a make variable with the same name and value. However, an explicit assignment in the makefile, or with a command argument, overrides the environment. Now I need to allow the user of my makefile to be able to pass arbitrary macro definitions from the “make.exe commandline” to “source code” right away, without having to change anything in the makefile. And be sure to use $(CFLAGS) in your compile command in the Makefile. As @jørgensen mentioned, putting the variable assignment after the make command will override the CFLAGS value already defined in the Makefile.
Simple assignment :=
Besides compiling source files you can use make to perform any task that can be described by shell commands. Another alternative is if you already installed MinGW and added the bin folder to the Path environment variable, you can use “mingw32-make” instead of “make”. There are plinko casino multiple rules-of-thumb, but I guess that setting to total amount to + 1 is the most common.
make: *** Error 1 error duplicate
On Linux machine most probably make will by GNU and to make user’s life isier make is soft linked to gmake. By using ‘gmake’ specifically you can use GNU make extensions without worrying about them being misinterpreted by some other make implementation. If you are familiar with programming in Linux, I highly recommend msys2. The purpose of “add path” is for convenience for your later use. From GNU Make error appendix, as you see this is not a Make error but an error coming from gcc.
Your Answer
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.
Paste the command in the Makefile directly to the command line and see what gcc says. Installation from GnuWin32 or via winget are good and easy options. This version lacks the very important option -O, which handles the output correctly when compiling multithreaded. You can use the -C flag to specify the path to your makefile. This way you can execute it from a different directory.The -f flag has a different use.
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.
Passing additional variables from command line to make
I know its a little late but other people with similar problem might get some help. By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy. But there is also the option of self compiling. And if you have to install make, which is used for compiling, this should be a valid option. If you’re using Windows 10, it is built into the Linux subsystem feature. Just launch a Bash prompt (press the Windows key, type bash and choose “Bash on Ubuntu on Windows”), cd to the directory you want to make, and type make.
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.
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.
