Why does Emacs's source tar archive contain *.elc files?

Why does Emacs's source tar archive contain *.elc files?

[Maksim Kislyakov]

Good day,

  I was playing around compiling Emacs from sources. At some point, I 
have found out that '*.tar' files with Emacs sources contain '*.elc' files.

As far as I understand, 'elc' is byte-compiled version of 'el' file.

- Why does the tar archive contain compiled sources? That seems strange. 
Source code archive (which you use to compile program) contains compiled 
code.

- Also, what will happen if I apply some patch before compiling Emacs? 
'el' file's modification time will be newer that corresponding 'elc' 
file's modification time.

Re: Why does Emacs's source tar archive contain *.elc files?

[Eli Zaretskii]

> Date: Wed, 17 Jul 2024 15:45:48 +0300
> From: Maksim Kislyakov <mail@kmaksim.dev>
> 
>   I was playing around compiling Emacs from sources. At some point, I 
> have found out that '*.tar' files with Emacs sources contain '*.elc' files.
> 
> As far as I understand, 'elc' is byte-compiled version of 'el' file.

Yes.

> - Why does the tar archive contain compiled sources? That seems strange. 
> Source code archive (which you use to compile program) contains compiled 
> code.

For the same reason the tarball includes other generated files: Info
manuals, the configure script, the few generated *.el files, the
configure script, etc.: it makes the build faster and requires fewer
development tools to be installed on the user's machine.

The actual line between the files that are provided in the release
tarballs and those which don't is NOT whether they are "compiled" in
some sense, but rather whether they are architecture-dependent or not.
The results of compiling *.c files are architecture-dependent, and
likewise the *.eln files produced by native compilation of Lisp code.
So we don't include those architecture-dependent files in the source
tarballs.

> - Also, what will happen if I apply some patch before compiling Emacs? 
> 'el' file's modification time will be newer that corresponding 'elc' 
> file's modification time.

If you modify some of the *.el files, then the "make" command will
recompile them and produce updated *.elc files.  Similarly with the
*texi source files of the Info manuals, and other generated files
which come with the tarball.

Re: Why does Emacs's source tar archive contain *.elc files?

[Maksim Kislyakov]

Thank you for your answer!

On 17.07.2024 16:16, Eli Zaretskii wrote:
>> Date: Wed, 17 Jul 2024 15:45:48 +0300
>> From: Maksim Kislyakov <mail@kmaksim.dev>
>>
>>    I was playing around compiling Emacs from sources. At some point, I
>> have found out that '*.tar' files with Emacs sources contain '*.elc' files.
>>
>> As far as I understand, 'elc' is byte-compiled version of 'el' file.
> Yes.
>
>> - Why does the tar archive contain compiled sources? That seems strange.
>> Source code archive (which you use to compile program) contains compiled
>> code.
> For the same reason the tarball includes other generated files: Info
> manuals, the configure script, the few generated *.el files, the
> configure script, etc.: it makes the build faster and requires fewer
> development tools to be installed on the user's machine.
>
> The actual line between the files that are provided in the release
> tarballs and those which don't is NOT whether they are "compiled" in
> some sense, but rather whether they are architecture-dependent or not.
> The results of compiling *.c files are architecture-dependent, and
> likewise the *.eln files produced by native compilation of Lisp code.
> So we don't include those architecture-dependent files in the source
> tarballs.
>
>> - Also, what will happen if I apply some patch before compiling Emacs?
>> 'el' file's modification time will be newer that corresponding 'elc'
>> file's modification time.
> If you modify some of the *.el files, then the "make" command will
> recompile them and produce updated *.elc files.  Similarly with the
> *texi source files of the Info manuals, and other generated files
> which come with the tarball.