Re: gnat compiler issues with a partial build

[jan.de.kruyf@gmail.com]

On Thursday, June 11, 2015 at 9:38:39 PM UTC+2, Simon Wright wrote:

> 
> > These checks are generated if you don't suppress them via -gnatp
> > regardless of the capabilities of the RTS.
> 
> Yes, but if you have pragma Restrictions (No_Exception_Propagation) and
> don't have an immediate handler the compiler will call
> Last_Chance_Handler directly instead of the __gnat_rcheck* subprograms.

right,
I did some digging over lunch.
The 'standard' gnat RTS builder, used elsewhere (which I probably copied from the ZFP package without checking) builds an RTS with '-gnatpg'. This, it appears, is what Adacore has taken as a standard way of doing things, if I understand the compiler source right.
And '-gnatp' indeed gets rid of the extra call-symbols. I cross-checked that by compiling one of the problem sources in various ways.

So Simon you were very right in saying that this is one of my alternatives.

However, I am not Adacore. I am just a casual programmer that builds a small RTS at odd times. moreover, I am not very precise. I need to test my doings extensively. This means to me that I must get all the help I can with finding my bugs. (You can never prove they are absent, only that they are present).

so then, I do not know how Adacore manages this, but it is a poor solution for me to just switch of runtime-checks for a first build of an RTS. (or in my case the files that eventually will constitute the RTS)

Ergo, I must put in dummies that trap those calls, and give some indication of what is happening. (Which is exactly what I did).

> Yes, but if you have pragma Restrictions (No_Exception_Propagation) and 
> don't have an immediate handler the compiler will call 
> Last_Chance_Handler directly instead of the __gnat_rcheck* subprograms. 

That is exactly the part that does not work. I have been through that now over and over with a nit comb.

In any case the whole issue is now documented in some way for whoever comes after us.

--

Besides I managed to get rid of the cruft in the building process of a partial compile for this kernel module that caused all this:

In the project file I now heave this:
---------------------------------------
package Builder is
      Global_Configuration_Pragmas := "gnat.adc";
      for Default_Switches ("ada") use
        ("-g", "-nostdlib",
         "--RTS=" & Project'project_dir);
      for Executable ("demo.adb") use "demo.x";
   end Builder;
---------------------------------------

the "-nostdlib" flag here causes the link process to forget about any regular libraries. In any other place (like in the linker package) did not work. Maybe I made a mistake then, I could not tell anymore.
The RTS points to nothing, because the lib is missing there.
The partial link file "demo.x" I use in the module building process downstream.

----------------------------------------
package Linker is
      for Default_Switches ("Ada") use ("-v", "-Xlinker","-r"); 
   end Linker;
----------------------------------------

the "-Xlinker","-r" passes '-r' to the linker program and causes a partial link.

Works like a dream now.

So thank you for your listening ear gentlemen. I highly appreciate it.
This type of interaction is for me often the only way to get out of a dark spot.

cheers,

j.