From @moritz

Rakudo 8207372ae394ca87667e974a2be2cd547def1f9c
on parrot r37565 (amd64 linux)

grammar Math {
  token TOP { ^ <value> $ {*} }
  token value { \d+ {*} }
}
class Actions {
  method value($/) { say 'in value()'; make 1..$/};
  method TOP($/) { say 'in TOP()'; make 1 + $/<value>};
}

my $x := Math.parse('234', :action(Actions.new));

say $x ?? 'matched' !! 'no match';

# Output​:
in value()
in TOP()
Segmentation fault

in gdb​:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f869d59c6f0 (LWP 10687)]
0x00007f869cd7bcac in Parrot_pcc_invoke_from_sig_object (interp=Cannot
access memory at address 0x7fffa4dc5828
)
  at src/call/pcc.c​:2917
2917 {
(gdb) bt
#​0 0x00007f869cd7bcac in Parrot_pcc_invoke_from_sig_object
(interp=Cannot acces
s memory at address 0x7fffa4dc5828
)
  at src/call/pcc.c​:2917
#​1 0x00007f869cd80102 in Parrot_pcc_invoke_sub_from_c_args
(interp=0x23ec010,
  sub_obj=0x25b4490, sig=0x7f869d0645b2 "P->I") at src/call/pcc.c​:2629
#​2 0x00007f869cf72e3e in Parrot_Object_get_integer (interp=0x23ec010,
  pmc=0x7f86986105d0) at ./src/pmc/object.pmc​:415
#​3 0x00007f869cd7973b in convert_arg_from_pmc (interp=0x23ec010,
  st=0x7fffa4dc9bf0) at src/call/pcc.c​:1113
#​4 0x00007f869cd7d475 in Parrot_convert_arg (interp=0x23ec010,
  st=0x7fffa4dc9bf0) at src/call/pcc.c​:1828
#​5 0x00007f869cd7e2c0 in Parrot_process_args (interp=0x23ec010,
  st=0x7fffa4dc9bf0, param_or_result=PARROT_PASS_RESULTS)
  at src/call/pcc.c​:1694
#​6 0x00007f869cd7e87b in parrot_pass_args (interp=0x23ec010,
  src_ctx=0x2db0750, dest_ctx=0x308e8d0, src_indexes=0x7f8698b6de48,
  dest_indexes=0x7f8698b6e218, param_or_result=PARROT_PASS_RESULTS)
  at src/call/pcc.c​:1884
#​7 0x00007f869cd1f0f4 in Parrot_set_returns_pc (cur_opcode=0x7f8698b6de48,
  interp=0x23ec010) at src/ops/core.ops​:656
#​8 0x00007f869cdd5ad5 in runops_slow_core (interp=0x23ec010,
  pc=0x7f8698b6de48) at src/runops_cores.c​:461
#​9 0x00007f869cd83765 in runops_int (interp=0x23ec010, offset=527)
  at src/interpreter.c​:980
#​10 0x00007f869cd8426a in runops (interp=0x23ec010, offs=527)
  at src/call/ops.c​:107
#​11 0x00007f869cd7c05e in Parrot_pcc_invoke_from_sig_object
(interp=0x23ec010,
  sub_obj=0x7f8698fcf3a0, sig_obj=0x7f8698f87280) at src/call/pcc.c​:2994
#​12 0x00007f869cd80102 in Parrot_pcc_invoke_sub_from_c_args
(interp=0x23ec010,
  sub_obj=0x7f8698fcf3a0, sig=0x7f869d0645b2 "P->I") at
src/call/pcc.c​:2629
#​13 0x00007f869cf72e3e in Parrot_Object_get_integer (interp=0x23ec010,
  pmc=0x7f869861bbb0) at ./src/pmc/object.pmc​:415
#​14 0x00007f869a3ba82d in Parrot_ObjectRef_get_integer (interp=0x23ec010,
  pmc=0x7f8698f88120) at ./objectref.pmc​:74
#​15 0x00007f869cec417a in Parrot_Integer_multi_cmp_DEFAULT
(interp=0x23ec010,
  pmc=0x7f8698f881b0, value=0x7f8698f88120) at ./src/pmc/integer.pmc​:1209
#​16 0x00007f869cda01a6 in pcf_I_JPP (interp=0x23ec010, self=0x24cbf90)
  at src/nci.c​:695
#​17 0x00007f869ceba617 in Parrot_NCI_invoke (interp=0x23ec010,
pmc=0x24cbf90,
  next=0x0) at ./src/pmc/nci.pmc​:330
#​18 0x00007f869cd7bf8a in Parrot_pcc_invoke_from_sig_object
(interp=0x23ec010,
  sub_obj=0x24cbf90, sig_obj=0x7f8698f87610) at src/call/pcc.c​:2980
#​19 0x00007f869cd91670 in Parrot_mmd_multi_dispatch_from_c_args (
  interp=0x23ec010, name=0x7f869d01161f "cmp", sig=0x7f869d0112e9 "PP->I")
  at src/multidispatch.c​:340
#​20 0x00007f869ce847b6 in Parrot_default_cmp (interp=0x23ec010,
  pmc=0x7f8698f881b0, value=0x7f8698f88120) at ./src/pmc/default.pmc​:2439
#​21 0x00007f869cf75d0e in Parrot_Object_cmp (interp=0x23ec010,
  pmc=0x7f8698f88270, value=0x7f8698f88120) at ./src/pmc/object.c​:1290
#​22 0x00007f869ccf1023 in Parrot_isle_i_p_p (cur_opcode=0x7f869d3ece38,
  interp=0x23ec010) at src/ops/cmp.ops​:793
#​23 0x00007f869cdd5ad5 in runops_slow_core (interp=0x23ec010,
  pc=0x7f869d3ece38) at src/runops_cores.c​:461
#​24 0x00007f869cd83765 in runops_int (interp=0x23ec010, offset=8394)
  at src/interpreter.c​:980
#​25 0x00007f869cd8426a in runops (interp=0x23ec010, offs=8394)
  at src/call/ops.c​:107
#​26 0x00007f869cd84646 in runops_args (interp=0x23ec010, sub=0x25b5390,
  obj=0x7f8698f883f0, meth_unused=0x23fadd0, sig=0x7f869d0644a7 "I",
  ap=0x7fffa4dd27a0) at src/call/ops.c​:254
#​27 0x00007f869cd8500d in Parrot_run_meth_fromc_args_reti
(interp=0x23ec010,
  sub=0x25b5390, obj=0x7f8698f883f0, meth=0x23fadd0,
sig=0x7f869d0644a7 "I")
  at src/call/ops.c​:492
#​28 0x00007f869cf72feb in Parrot_Object_get_bool (interp=0x23ec010,
  pmc=0x7f8698f883f0) at ./src/pmc/object.c​:2305
#​29 0x00007f869cce7be3 in Parrot_unless_p_ic (cur_opcode=0x7f869d3ebdf0,
  interp=0x23ec010) at src/ops/core.ops​:433
#​30 0x00007f869cdd5ad5 in runops_slow_core (interp=0x23ec010,
  pc=0x7f869d3ebdf0) at src/runops_cores.c​:461
#​31 0x00007f869cd83765 in runops_int (interp=0x23ec010, offset=8661)
...

Looks like an infinite loop, the backtrace goes on quite long...

Moritz

From @moritz

Works now, just needs tests.

@moritz - Status changed from 'new' to 'open'

From @moritz

Tested in t/spec/S05-grammar/action-stubs.t

@moritz - Status changed from 'open' to 'resolved'