Re: MinGW-w64 gnatlink "undefined reference"

[Simon Wright <simon@pushface.org>]

mjamesb <mjamesb> writes:

> x86_64-w64-mingw32-gnatlink helloworld.ali
> /usr/lib/gcc/x86_64-w64-mingw32/4.5.2/adalib/libgnat.a(s-exctab.o): In function `system__exception_table__internal_exception':
> /home/user/mingw64/mingw64-x86_64-gcc-4.5.2-1/build/gcc/ada/rts/s-exctab.adb:154: undefined reference to `__gnat_eh_personality_sj'

What this is saying is that the RTS (run time system) s-exctab.o
(System.Exception_Table) contains a reference which isn't satisfied.

This is nothing to do with your code, it's that Ada.Text_IO calls in
vast chunks of the RTS including exception handling.

To see what's happening at link time, you'd need to ask for verbose
linker output:

- for verbose output from gnatlink (which calls up the linker):
$ gnatmake helloworld.adb -largs -v

- for verbose output from the linker itself:
$ gnatmake helloworld.adb -largs -Wl,-v 


'__gnat_eh_personality_sj' is to do with the way the RTS handles
 exceptions. Reading between the lines in
 http://gcc.gnu.org/onlinedocs/gcc-4.5.0/gnat_ugn_unw/Exception-Handling-Control.html
 your problem will be related to the setjmp/longjmp method, and you
 could try 'gnatmake helloworld.adb --RTS=zcx', but in any
 case there's no excuse for the default RTS to be incomplete. I think
 you need to take this up with whoever built your compiler.