Re: completion for compilers (cc, gcc...) and -o

[Vincent Lefevre <vincent@xxxxxxxxxx>]

On 2020-04-30 18:14:59 +0000, Daniel Shahaf wrote:
> Vincent Lefevre wrote on Thu, 30 Apr 2020 10:51 +0200:
> > The -o option is currently handled by
> > 
> >   '-o:output file:_files -g "^*.(c|h|cc|C|cxx)(-.)"'
> > 
> > I wonder whether .i files (preprocessed files, e.g. for bug reports)
> > should be excluded too. One can choose such files for output with
> > "gcc -E", but:
> >   * in this case, one generally chooses to use the shorter ">" (or a
> >     pipe) rather than "-o" (gcc -E file.c > file.i);
> 
> I don't see how the existence of other ways to create .i files is
> a reason not to complete .i files after -o.

I've googled a bit, and most examples with -E and storage in a file
used the redirection. BTW, all examples used the -E first, so perhaps
accept .i files for -o only when -E is present.

Note that GCC describes .i files as source files (among other
extensions of source files).

> >   * using such files as a source may be more common.
> 
> Assuming so arguendo, how does that bear on what the completion function should do?
> 
> > Moreover, if I have a C source "myprogram.c", I generally want the
> > output file (program name) to be "myprogram", or if I need several
> > versions (e.g. because I test several options), I choose this as a
> > prefix, e.g. for "myprogram1", "myprogram2", "myprogram-ok", etc.
> > Now, when "myprogram.c" exists, but not any of the program files,
> > and I try to complete with
> > 
> >   cc -o my[TAB]
> > 
> > I'd like the "myprogram" to be taken into account.
> > 
> > Currently it seems that if there are no matches without the excluded
> > pattern, the completion is done on all files, that is, one gets
> > 
> >   cc -o myprogram.c
> > 
> > This does not make any sense since a .c file should normally not be
> > an output file. IMHO, instead of that, one should get the filename
> > without the filename extension:
> > 
> >   cc -o myprogram
> 
> Offering basenames seems rather like your own personal preference, not
> something that the completion system should assume everybody does.
> However, refraining from offering .c files when there are no non-.c
> files around is probably a good idea.

Actually, many people do this (for compiling individual source
files, otherwise for multi-source projects, a Makefile is used
in general). But it's true that the output file may not be one
that is the basename of a source file. I think of 2 possibilities
(perhaps this should be configurable by the user) for -o:

1. For the completion, consider all existing non-source items
   (files and directories) + the basename of each source file.

2. Consider all existing non-source items, and if there are no
   candidates for the completion, then consider the basename of
   each source file.

-- 
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)