[Caml-list] Missing stack frames

[Caml-list] Missing stack frames

[Nicolas Cannasse]

Hi,

While debugging the haXe compiler (http://haxe.org, entirely written in 
OCaml) I got a Not_found exception in native mode. However using 
OCAMLRUNPARAM=b was only giving me the first 4-5 stack frames, making it 
impossible to debug.

I noticed that it was caused by an exception raised from a CMXA library 
that was not compiled with -g. That would not be a big issue since I 
don't want to debug the library itself but a lot of my software stack 
frames was also removed.

Is it a known issue ?

I'm using 3.11.0 MSVC on WinXP32 (since there is no 3.12 MSVC available 
yet).

In order to reproduce, you can :

a) download haXe SVN r3766 (binary on http://haxe.cmt.tc/, sources on 
http://haxe.googlecode.com/svn/trunk/

b) create the following file named "Test.hx" :

enum E { A; B; }
class Test {
   public function run() {
     switch(A) { case A: var id = 0; return; case B: var id = 0; }
   }
}

c) compile with "haxe Test.hx"

The full actual stack frame should be :

Fatal error: exception Not_found
Raised at file "pMap.ml", line 107, characters 21-30
Called from file "pMap.ml", line 150, characters 15-20
Called from file "pMap.ml", line 151, characters 21-29
Called from file "codegen.ml", line 686, characters 30-47
Called from file "list.ml", line 69, characters 12-15
Called from file "list.ml", line 69, characters 12-15
Called from file "codegen.ml", line 710, characters 3-27
Called from file "codegen.ml", line 746, characters 3-22
Called from file "codegen.ml", line 798, characters 1-24
Called from file "list.ml", line 74, characters 24-34
Called from file "codegen.ml", line 812, characters 23-66
Called from file "list.ml", line 69, characters 12-15
Called from file "codegen.ml", line 814, characters 3-46
Called from file "list.ml", line 69, characters 12-15
Called from file "main.ml", line 609, characters 2-34
Called from file "main.ml", line 726, characters 0-52

The stack frame we get if extLib (which contains pMap.ml) is not 
compiled with -g is :

Called from file "main.ml", line 609, characters 2-34
Called from file "main.ml", line 726, characters 0-52

Best Regards,
Nicolas

Re: [Caml-list] Missing stack frames

[ygrek]

On Thu, 07 Apr 2011 12:45:57 +0200
Nicolas Cannasse <ncannasse@motion-twin.com> wrote:

> I noticed that it was caused by an exception raised from a CMXA library 
> that was not compiled with -g. That would not be a big issue since I 
> don't want to debug the library itself but a lot of my software stack 
> frames was also removed.
> 
> Is it a known issue ?

I have reported similar issue at http://caml.inria.fr/mantis/view.php?id=5074
Trivia: noticed it when using extlib from debian which was (still is?) compiled without -g

-- 
 ygrek
 http://ygrek.org.ua