https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123673
Bug ID: 123673
Summary: [PDT] seg fault on composite PDT function result
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: damian at archaeologic dot codes
Target Milestone: ---
$ cat reproducer.f90
module input_output_pair_m
implicit none
! Moving the contents of this module to the main program causes several
! compile-time errors that do not occur with the ifx compiler
type tensor_t(k)
integer, kind :: k = kind(1.)
real(k), allocatable :: values_(:)
end type
type input_output_pair_t(k)
integer, kind :: k = kind(1.)
type(tensor_t(k)) inputs_, expected_outputs_
end type
contains
! Moving just the function below to become an internal subprogram in the main
program
! causes similar compile-time errors to those mentioned above
type(input_output_pair_t) elemental function input_output_pair(inputs,
expected_outputs)
type(tensor_t), intent(in) :: inputs, expected_outputs
input_output_pair%inputs_ = inputs
input_output_pair%expected_outputs_ = expected_outputs
end function
end module
program trainable_network_test
use input_output_pair_m
implicit none
type bin_t
integer first_, last_
end type
! Removing the mini_batch_t's all instances of 'k' below causes
! the followingn compile-time error on the above 'use' statement:
! "Cannot convert TYPE(input_output_pair_t) to TYPE(Pdtinput_output_pair_t_4)
at (1)",
! where "1" is positiioned just after 'use'
type mini_batch_t(k)
integer, kind :: k = kind(1.)
type(input_output_pair_t(k)), allocatable :: input_output_pairs_(:)
end type
type(input_output_pair_t), allocatable :: input_output_pairs(:)
type(bin_t), allocatable :: bins(:)
type(mini_batch_t) mini_batch_1
integer, parameter :: num_pairs = 7 ! 7 is the mininum value that causes
segmentation fault
integer, parameter :: n_bins = 2 ! 2 is the mininum value that causes
segmentation fault
integer p, b
input_output_pairs = input_output_pair([(tensor_t([0.,0.]), p = 1,
num_pairs)], [(tensor_t([0.,0.]), p = 1, num_pairs)])
bins = [(bin(num_pairs, n_bins, b), b = 1, n_bins)]
! The final exectuable statement below causes a segmentation fault with
gfortran.
! Converting the assignment to an 'associate' statement also causes a seg
fault.
mini_batch_1 = mini_batch(input_output_pairs(bins(1)%first_:bins(1)%last_))
contains
type(bin_t) function bin(num_items, num_bins, bin_number)
integer num_items, num_bins, bin_number
associate(remainder => mod(num_items, num_bins), items_per_bin =>
num_items/num_bins)
if (bin_number <= remainder) then
bin%first_ = 1 + (bin_number-1)*(items_per_bin+1)
bin%last_ = bin_number*(items_per_bin+1)
else
bin%first_ = 1 + (remainder-1)*(items_per_bin+1) + 1 +
(bin_number-remainder)*items_per_bin
bin%last_ = remainder*(items_per_bin+1) +
(bin_number-remainder)*items_per_bin
end if
end associate
end function
type(mini_batch_t) function mini_batch(input_output_pairs)
type(input_output_pair_t) input_output_pairs(:)
mini_batch%input_output_pairs_ = input_output_pairs
end function
end program
$ gfortran reproducer.f90
$ ./a.out
free(): double free detected in tcache 2
Program received signal SIGABRT: Process abort signal.
Backtrace for this error:
#0 0x7f4e8898a51f in ???
at ./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
#1 0x7f4e889de9fc in __pthread_kill_implementation
at ./nptl/pthread_kill.c:44
#2 0x7f4e889de9fc in __pthread_kill_internal
at ./nptl/pthread_kill.c:78
#3 0x7f4e889de9fc in __GI___pthread_kill
at ./nptl/pthread_kill.c:89
#4 0x7f4e8898a475 in __GI_raise
at ../sysdeps/posix/raise.c:26
#5 0x7f4e889707f2 in __GI_abort
at ./stdlib/abort.c:79
#6 0x7f4e889d1676 in __libc_message
at ../sysdeps/posix/libc_fatal.c:156
#7 0x7f4e889e8cfb in malloc_printerr
at ./malloc/malloc.c:5664
#8 0x7f4e889eb0aa in _int_free
at ./malloc/malloc.c:4473
#9 0x7f4e889ed452 in __GI___libc_free
at ./malloc/malloc.c:3391
#10 0x404a4d in ???
#11 0x405016 in ???
#12 0x7f4e88971d8f in __libc_start_call_main
at ../sysdeps/nptl/libc_start_call_main.h:58
#13 0x7f4e88971e3f in __libc_start_main_impl
at ../csu/libc-start.c:392
#14 0x4010b4 in ???
#15 0xffffffffffffffff in ???
Aborted (core dumped)
$ gfortran --version
GNU Fortran (GCC) 16.0.1 20260116 (experimental)
