Re: [Caml-list] filename and line number.

[Till Varoquaux <till@pps.jussieu.fr>]

On Tue, Aug 2, 2011 at 8:45 AM, Gabriel Scherer
<gabriel.scherer@gmail.com> wrote:
> There is a "macro" syntax extension that is distributed with Camlp4,
> and can do basic cpp-like stuff, including __FILE__ and a __LOCATION__
> macros.
>
> For example, the following content, named test.ml:
>
>  let test =
>    __LOCATION__
>
> When processed through 'camlp4o pa_macro.cmo', will result in:
>
>  let test = Loc.of_tuple ("test.ml", 2, 13, 17, 2, 13, 29, false)
>
> (To compile:  ocamlc -pp 'camlp4o pa_macro.cmo' ...)
>
> The "Loc.of_tuple" call is a reference to a function implemented in
> Camlp4 Loc module; if you make you project depend (at runtime, not
> camlp4-time) on Camlp4 loc-handling libraries, you'll get functions to
> manipulate the location and its information. You can also define your
> own Loc module in test.ml:
>
>  module Loc = struct
>    let of_tuple
>      ((file_name, start_line, start_bol, start_off, stop_line,
> stop_bol, stop_off, is_ghost) as loc) =
>        loc
>  end
>
>  let test =
>    __LOCATION__
>
> The source code (and some documentation in the head comment) for the
> "macro" camlp4 extension is in
> camlp4/Camlp4Parsers/Camlp4MacroParser.ml in the ocaml source tree.
>
> The meaning of the weird tuple arguments can be found in the Camlp4
> documentation. I have a not exactly up-to-date (I guess ocaml 3.11)
> version of the documentation on my website, see:
>  http://bluestorm.info/camlp4//camlp4-doc/Sig.Loc.html

Having camlp4's ocamldoc is pretty nice. How did you generate those?
Is there a makefile target?

Till
>
> Finally, Martin Jambon also has its own "cppo" tools mimicking cpp,
> which I suppose doesn't rely on camlp4, and has __FILE__ and __LINE__
> macros which may be in a more directly exploitable format. I have
> never tried it though. See:
>  http://martin.jambon.free.fr/cppo.html
>
> On Tue, Aug 2, 2011 at 2:20 PM, Anders Fugmann <anders@fugmann.net> wrote:
>> Hi,
>>
>> Do there exist a way to get filename and linenumber of the calling function
>> - Or at least the of the current filename and line number?
>>
>> I guess this would involve a syntax camlp4 syntax extension, but I'm not a
>> camlp4 wizard and google did not come up with any suggestions.
>>
>> Regards
>> Anders Fugmann
>>
>>
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>
>
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