Re: simple code can't compiled, without clear compiler warning (not clear enough to me at least)

["A. Cervetti" <andrea.cervetti@gmail.com>]

wednesday 29 november 2017 16:17:03 UTC+1, Mehdi Saada wrote:

> $ gcc-6 -c tri_selection.ads 
> cannot generate code for file tri_selection.ads (package spec) 
> gnatmake: "tri_selection.ads" compilation error 
> 
> I thought specifications could be compiled separately ?

Yes, they can, but for syntax check only. They cannot generate code (like explained in the message).

try: gcc-6 -gnats -c tri_selection.ads
> 
> the body can't compiled either.

> gcc-6 -c tri_selection.adb 
> tri_selection.adb:7:35: expected type "Indice_type" defined at tri_selection.ads:3 
> tri_selection.adb:7:35: found type "Element_type" defined at tri_selection.ads:2 
> tri_selection.adb:8:27: expected type "Indice_type" defined at tri_selection.ads:3 
> tri_selection.adb:8:27: found type "Element_type" defined at tri_selection.ads:2 
> tri_selection.adb:8:35: expected type "Indice_type" defined at tri_selection.ads:3 
> tri_selection.adb:8:35: found type "Element_type" defined at tri_selection.ads:2 
> tri_selection.adb:9:27: expected type "Indice_type" defined at tri_selection.ads:3 
> tri_selection.adb:9:27: found type "Element_type" defined at tri_selection.ads:2 
> tri_selection.adb:9:35: expected type "Indice_type" defined at tri_selection.ads:3 
> tri_selection.adb:9:35: found type "Element_type" defined at tri_selection.ads:2 
> tri_selection.adb:19:33: expected type "Element_type" defined at tri_selection.ads:2 
> tri_selection.adb:19:33: found type "Indice_type" defined at tri_selection.ads:3 
> gnatmake: "tri_selection.adb" compilation error

I think that the message are enough self explicative.
You defined the parameters A and B as Element_Type:
> procedure Swap (T: in out Tableau_type; A, B : in out Element_type)

than you used them as indexes:
>          temp := T(A);
>          T(A) := T(B);

the indexes should be Indice_type.

also you called Swap with the actual parameter temp and Tableau_type'Last
that are Index_type.

redefine Swap as
procedure Swap (T: in out Tableau_type; A, B : in out indice_type)

Now there are other errors, but I'll leave to you the pleasure of discovery.

A.