deepakvashist / cpp-learning

C++ learning

Object Files

When you compile a project with g++, g++ actually performs a several distinct tasks:

1. The preprocessor runs and executes any statement beginning with a hash symbol: #, such as #include statements. This ensures all code is in the correct location and ready to compile.
2. Each file in the source code is compiled into an "object file" (a .o file). Object files are platform-specific machine code that will be used to create an executable.
3. The object files are "linked" together to make a single executable. In the examples you have seen so far, this executable is a.out, but you can specify whatever name you want.

It is possible to have g++ perform each of the steps separately by using the -c flag. For example:

g++ -c main.cpp

will produce a main.o file, and that file can be converted to an executable with:

g++ main.o

References

• #include guard
• Build systems
• CMake