CODEWITHSUNDEEP
c++unixerror-handlingmakefile
Jedi Wolf
Jedi Wolf

Reputation: 361

Stop all makefile actions when C++ hits error call in unix

I have a makefile that does multiple things, including calling a bash file and making a C++ file. In the bash file I have the code:

echo "${variable}: Error" 1>&2
exit 1

Which prints error text then exits the batch file and the makefile, stopping it. I want to do the same thing with the C++ code. I can throw an error and stop the C++ code at wherever the error was thrown, but I can't seem to figure out a way to make it stop the makefile as well. Is there a way to do this? Thanks for the help.

Edit: Mentioned in a comment below, but the makefile both compiles the code then runs it in the next section so it would be best to be able to break out of the makefile both on a compile error and a run error.

Upvotes: 2

Views: 209

Answers (2)

Magnus Hoff
Magnus Hoff

Reputation: 22089

To signify an error status during runtime of a C++-program, you can do the following:

Printing an error to the error stream is done with std::cerr:

std::cerr << "This will not do!\n";

Passing an error status that make will understand is done by returning a non-zero value from main:

int main() {
    // Your program
    if (error_condition) {
        std::cerr << "This will not do!\n";
        return 1;
    }
}

You can also terminate the program, optionally with an error status, from anywhere in the program using the exit function from #include <cstdlib>:

#include <cstdlib>

void not_main() {
    std::exit(1); // Non-zero value here indicates error status to make
}

int main() {
    not_main();
}

Upvotes: 2

Jonathon Reinhart
Jonathon Reinhart

Reputation: 137398

Since you're talking about Makefiles, I'm assuming that you want to stop the Makefile during the compilation of the C++ program (and not the execution of the resulting program).

If that's the case, use the #error preprocessor directive.

 #if !defined(FOO) && defined(BAR)
 #error "BAR requires FOO."
 #endif

Reference:

Upvotes: 3

Related Questions