Re: [RFA] Add new language: "unsupported"

[Daniel Berlin <dberlin at dberlin dot org>]

On Tuesday, May 6, 2003, at 09:42  PM, Joel Brobecker wrote:

> As promised to Elena, this is a followup on:
>
>     http://sources.redhat.com/ml/gdb-patches/2003-04/msg00209.html
>
> Basically, I added a new "unsupported" language which support is
> minimalistic (identical to what we do with the "asm" language).
> I didn't fancy "partial":
>
>         (gdb) show lang
>         Current language:  auto; currently partial
>
> I felt like it could confuse the user to think that "partial" is the
> name of a real language :-). But I'm not such a big fan of 
> "unsupported"
> either, so all suggestions are welcome.
>
> This new language will first be used by the dwarf2 reader, for objects
> which language is currently not supported. What it does, at the moment,
> is use the "unknown" language, which makes a lot of the GDB commands
> fall flat. Like so, when debugging an Ada program:
>
>     (gdb) list foo.adb:1
>     internal error - unimplemented function 
> unk_lang_create_fundamental_type called.
>     (gdb) quit
>
> With the attached patch, and also the little patch to dwarf2read.c
> (attached too, will be submitted later, after this one is agreed on),
> GDB behaves in a much more friendly way:
>
>     (gdb) list foo.adb:1
>     1       procedure Foo is
>     2          A : Integer := 1;
>     3       begin
>     4          A := A + 1;
>     5       end Foo;
>     (gdb) b foo.adb:4
>     Breakpoint 1 at 0x8049769: file foo.adb, line 4.
>     (gdb) run
>     Starting program: /lek.a/brobecke/ada_example/foo
>
>     Breakpoint 1, _ada_foo () at foo.adb:4
>     4          A := A + 1;
>     Current language:  auto; currently unsupported
>     (gdb) p a
>     $1 = 1



It should probably warn (I guess it has to be in the reader, since we 
have no hook for when you switch to a language, right?) when it is 
switching to the unsupported language.

Something like "Warning: The current language is unsupported by GDB. 
Name lookups and printouts may not look like what you expect as a 
result".

That way, nobody files bugs because the unsupported language does what 
C would do, when they expect what <insert other language here> would do.