Re: GNAT compiler versions and addr2line

["Alejandro R. Mosteo" <alejandro@mosteo.com>]

On 22/08/18 15:01, Phil wrote:
> Hi,
> 
> I'm having problems getting useful debugging data from some GNAT
> versions.  If I use the Debian FSF version (6.3.0), I get very little
> useful unless running inside gdb.  In particular, the trace addresses
> don't resolve to anything through addr2line.

I have seen the same up to current 7.3 FSF Ubuntu versions, and still 
haven't found a workaround :/

Alex.

> 
> Given this test program:
>      $ cat foo.adb
>      procedure Foo is
> 
>         procedure Able is
>         begin
> 	  raise Constraint_Error with "It broke";
>         end Able;
> 
>         procedure Baker is
>         begin
> 	  Able;
>         end Baker;
> 
>      begin
>         Baker;
>      end Foo;
> 
> Check the compiler version:
> 
>      $ gnatmake --version
>      GNATMAKE 6.3.0
>      […]
> 
> Build with debug info and binder argument -E:
> 
>      $ gnatmake -g foo -bargs -E
>      […]
> 
> Run and try to use addr2line to get more information:
>      $ ./foo
>      Execution terminated by unhandled exception
>      raised CONSTRAINT_ERROR : It broke
>      Call stack traceback locations:
>      0x55654f763530 0x55654f763566 0x55654f76354c 0x55654f7634e8 0x7f11a88292df 0x55654f763238 0xfffffffffffffffe
> 
>      $ addr2line -e foo -f 0x55654f763530 0x55654f763566 0x55654f76354c 0x55654f7634e8 0x7f11a88292df 0x55654f763238 0xfffffffffffffffe
>      ??
>      ??:0
>      […and repeats ??, ??:0…]
> 
> Now, gdb using “catch exception” and “bt” will show some debugging:
>      (gdb) bt
>      #0  <__gnat_debug_raise_exception> (e=0x5555557560c0 <constraint_error>,
> 	message=...) at s-excdeb.adb:40
>      #1  0x00007ffff797603e in ada.exceptions.complete_occurrence (
> 	x=x@entry=0x555555757050) at a-except.adb:925
>      #2  0x00007ffff797604d in ada.exceptions.complete_and_propagate_occurrence (
> 	x=x@entry=0x555555757050) at a-except.adb:936
>      #3  0x00007ffff79760a0 in <__gnat_raise_exception> (
> 	e=0x5555557560c0 <constraint_error>, message=...) at a-except.adb:978
>      #4  0x0000555555555532 in foo.able () at foo.adb:5
>      #5  0x0000555555555568 in foo.baker () at foo.adb:10
>      #6  0x000055555555554e in foo () at foo.adb:14
> So the debugging data is accessible (somehow).
> 
> The same problem occurs with version 7.3.0 (from Debian unstable).  It
> works if I use the current AdaCore community version instead:
> 
>      $ gnatmake --version
>      GNATMAKE Community 2018 (20180524-73)
>      $ ./foo
> 
>      Execution of ./foo terminated by unhandled exception
>      raised CONSTRAINT_ERROR : It broke
>      Call stack traceback locations:
>      0x4024e4 0x402519 0x402500 0x402473 0x7fb92acb72df 0x4020b8 0xfffffffffffffffe
>      $ addr2line -e foo -f 0x4024e4 0x402519 0x402500 0x402473 0x7fb92acb72df 0x4020b8 0xfffffffffffffffe
>      foo__able
>      /tmp/ada/foo.adb:5
>      foo__baker
>      /tmp/ada/foo.adb:10
>      _ada_foo
>      /tmp/ada/foo.adb:14
>      main
>      /tmp/ada/b~foo.adb:185
>      […]
> 
> 
> I started looking at this because of problems using GNAT.Traceback.Symbolic
> (the 6.3.0 version has a stub version isn't useful).  Getting
> addr2line working would be very helpful.  I assume (hope!) it's a
> PBCAK issue — does anyone have a suggestion for getting addr2line
> working with the Debian/FSF versions? Am I missing something on the
> command line?
> 
> TIA,
> 
> Phil.
> 
> 
> 
>