https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122578
Bug ID: 122578
Summary: [PDT] untyped associate name , unrecognized component
declaration, unresolved generic binding
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: ---
At 98 lines, this bountiful bug harvest is longer than usual because I can't
tell whether the 3 errors are distinct or a cascade. My versions of ifx,
nagfor, and LLVM flang all compile this code without an error or warning
message. I hope the larger context is helpful.
$ cat neural_network_m.f90
module tensor_map_m
use iso_c_binding, only : c_int
implicit none
type tensor_t(k)
integer, kind :: k = kind(1.)
real(k), allocatable :: values_(:)
contains
generic :: values => default_real_values
procedure default_real_values
end type
interface
module function default_real_values(self) result(tensor_values)
implicit none
class(tensor_t) self
real, allocatable :: tensor_values(:)
end function
end interface
type tensor_map_t(k)
integer, kind :: k = kind(1.)
real(k), dimension(:), allocatable :: intercept_, slope_
contains
generic :: map_to_training_range => default_real_map_to_training_range
procedure :: default_real_map_to_training_range
generic :: map_from_training_range => default_real_map_from_training_range
procedure :: default_real_map_from_training_range
end type
interface
elemental module function default_real_map_to_training_range(self, tensor)
result(normalized_tensor)
implicit none
class(tensor_map_t), intent(in) :: self
type(tensor_t), intent(in) :: tensor
type(tensor_t) normalized_tensor
end function
elemental module function default_real_map_from_training_range(self,
tensor) result(unnormalized_tensor)
implicit none
class(tensor_map_t), intent(in) :: self
type(tensor_t), intent(in) :: tensor
type(tensor_t) unnormalized_tensor
end function
end interface
type activation_t
integer(c_int) :: selection_
contains
generic :: evaluate => default_real_evaluate
procedure default_real_evaluate
end type
interface
elemental module function default_real_evaluate(self, x) result(y)
implicit none
class(activation_t), intent(in) :: self
real, intent(in) :: x
real y
end function
end interface
type neural_network_t(k)
integer, kind :: k = kind(1.)
type(tensor_map_t(k)) input_map_, output_map_
real(k), allocatable :: weights_(:,:,:), biases_(:,:)
integer, allocatable :: nodes_(:)
type(activation_t) :: activation_
contains
generic :: infer => default_real_infer
procedure default_real_infer
end type
integer, parameter :: input_layer = 0
contains
elemental function default_real_infer(self, inputs) result(outputs)
class(neural_network_t), intent(in) :: self
type(tensor_t), intent(in) :: inputs
type(tensor_t) outputs
real, allocatable :: a(:,:)
integer l
associate(w => self%weights_, b => self%biases_, n => self%nodes_,
output_layer => ubound(self%nodes_,1))
allocate(a(maxval(n), input_layer:output_layer))
associate(normalized_inputs =>
self%input_map_%map_to_training_range(inputs))
a(1:n(input_layer),input_layer) = normalized_inputs%values()
end associate
feed_forward: &
do l = input_layer+1, output_layer
associate(z => matmul(w(1:n(l),1:n(l-1),l), a(1:n(l-1),l-1)) +
b(1:n(l),l))
a(1:n(l),l) = self%activation_%evaluate(z)
end associate
end do feed_forward
associate(normalized_outputs => tensor_t(a(1:n(output_layer),
output_layer)))
outputs = self%output_map_%map_from_training_range(normalized_outputs)
end associate
end associate
end function
end module
$ gfortran -c neural_network_m.f90
neural_network_m.f90:85:61:
85 | a(1:n(input_layer),input_layer) = normalized_inputs%values()
| 1
Error: Symbol ‘normalized_inputs’ at (1) has no IMPLICIT type
neural_network_m.f90:7:38:
7 | real(k), allocatable :: values_(:)
| 1
Error: Cannot convert REAL(0) to REAL(4) at (1)
neural_network_m.f90:94:18:
94 | outputs =
self%output_map_%map_from_training_range(normalized_outputs)
| 1
Error: Found no matching specific binding for the call to the GENERIC
‘map_from_training_range’ at (1)
$ gfortran --version
GNU Fortran (GCC) 16.0.0 20251105 (experimental)
