Liron Malul Liron Malul - 1 month ago 15
C Question

Linker and complitation in C

I just read a paragraph about linker and complitation in C so i this is what I understood from it : compiler in c/c++ turns the file instead of .c/.cpp (except checking if the code is valid lets assume that the code is valid) to .o/.obj which inside of it the code is written in machine code(binary) and when you run the code it does linking and it takes the object file which was created from the original .c / .cpp and turns it into and executable file that the machine can read ?

can you plz tell me if that is truth ?

Answer

The truth but somewhat simplistic.

The compiler generates object code from source code - it compiles a single translation unit. The object code comprises of certainly machine code, but it is not directly executable since it contains unresolved symbols to library code and to code from other separately compiled translation units. Thes symbolic links are calls or references to code and data whose address is not yet resolved.

The linker brings together multiple object code modules from compiled translation units and from library code (such as the standard library, operating system API etc.), and resolves unresolved symbols(i.e. links everything together). In an OS hosted environment, the linker also adds information required by the OS to load the executable.

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