[Bug modula2/108404] New: M2RTS_Halt fails with a segv (it should emit a diagnostic and exit).

["iains at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108404

            Bug ID: 108404
           Summary: M2RTS_Halt fails with a segv (it should emit a
                    diagnostic and exit).
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: modula2
          Assignee: gaius at gcc dot gnu.org
          Reporter: iains at gcc dot gnu.org
  Target Milestone: ---

On Darwin several tests fail because there is an invalid stack size set (that
is a separate bug).

The fault should have been reported by M2RTS_Halt (it is detected correctly in
Rico.cc).

Setting a break point on the entry to M2RTS_Halt :

* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
    frame #0: 0x00000001000054f0 concurrentstore.x0`M2RTS_Halt at
M2RTS.mod:296:1
   293  
   294  PROCEDURE Halt (file: ARRAY OF CHAR; line: CARDINAL;
   295                  function: ARRAY OF CHAR; description: ARRAY OF CHAR) ;
-> 296  BEGIN
   297     ErrorMessage (description, file, line, function) ;
   298     HALT
   299  END Halt ;

examining the registers:

(lldb) reg read
General Purpose Registers:
       rax = 0x0000000000000016
       rbx = 0x0000600002c08118
       rcx = 0x0000000100014c00  "failed to set stack size attribute"
       rdx = 0x0000000100014bf2  "initThread"
       rdi = 0x0000000100014b00 
"/src-local/gcc-master/libgm2/libm2iso/RTco.cc"
       rsi = 0x0000000000000172

this is correct ABI - RDI - file, RSI = line number, RDX = function, RCX =
message.
(four integer/pointer arguments).

---- however if we continue from this point ...

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS
(code=2, address=0x3014e7178)
    frame #0: 0x000000010000554f concurrentstore.x0`M2RTS_Halt at
M2RTS.mod:296:1
   293  
   294  PROCEDURE Halt (file: ARRAY OF CHAR; line: CARDINAL;
   295                  function: ARRAY OF CHAR; description: ARRAY OF CHAR) ;
-> 296  BEGIN
   297     ErrorMessage (description, file, line, function) ;

I cannot (at present) debug this further since I do not have an installed
debugger that supports Module-2 (but it might  well repeat on Linux - the ABI
is basically the same).  In any case, it seems likely that the problem is in
the prologue or very early in the function since the break line is on BEGIN in
both cases.