Re: The .obj file, what is it?

2017-05-03 Thread Stanislav Blinov via Digitalmars-d-learn

On Wednesday, 3 May 2017 at 10:55:44 UTC, I Lindström wrote:
So, a question from a beginner. What is the .obj file that 
appears after the source is compiled into the executable? I 
can't find a good explanation on the Net for it. I take it the 
file has to accompany the executable for the program to 
function since the online explanations I've found say it 
contains instructions and is related to memory management? It's 
been bugging me from the start.


The source is not compiled into the executable. The source is 
compiled into a "object code", output into an "object file" - in 
this case, the .obj file. Afterwards, object files are linked by 
a linker (usually also taking other object files and/or 
libraries) to produce an executable or a library.
.obj files are not needed to be redistributed, they've served 
their purpose when the final target executable or library has 
been created. But it's useful to keep them in the development 
environment, as usually the build environment would not spend 
time recompiling the code when an up-to-date object files are 
present.


Re: The .obj file, what is it?

2017-05-03 Thread I Lindström via Digitalmars-d-learn

On Wednesday, 3 May 2017 at 11:09:33 UTC, Stanislav Blinov wrote:


The source is not compiled into the executable. The source is 
compiled into a "object code", output into an "object file" - 
in this case, the .obj file. Afterwards, object files are 
linked by a linker (usually also taking other object files 
and/or libraries) to produce an executable or a library.
.obj files are not needed to be redistributed, they've served 
their purpose when the final target executable or library has 
been created. But it's useful to keep them in the development 
environment, as usually the build environment would not spend 
time recompiling the code when an up-to-date object files are 
present.


O... Many thanks. This cleared it for me. What happens at 
compile time is all magic to me still, but learning as I go.




Re: The .obj file, what is it?

2017-05-03 Thread Adam D. Ruppe via Digitalmars-d-learn
Basically, .obj is a temporary file the compiler uses to store 
its half-finished work on the way to producing the exe.


Once you have the exe, the obj is no longer necessary, but 
keeping them around can sometimes speed up recompiles by reusing 
the left over work from last time. (Not so much in D though, this 
more applies to C.)