subtypes function not working as in 0.5

[thofma]

On 0.5:

julia> abstract C{T}

julia> type B{Int} <: C{Int} end

julia> subtypes(C)
1-element Array{Any,1}:
 B{Int}

On latest master:

julia> abstract C{T}

julia> type B{Int} <: C{Int} end

julia> subtypes(C)
ERROR: MethodError: no method matching subtypes(::Type{C})
Closest candidates are:
  subtypes(::Module, ::DataType) at reflection.jl:316
  subtypes(::DataType) at reflection.jl:333

julia> B{Int} <: C
true

julia> versioninfo()
Julia Version 0.6.0-dev.2130
Commit 00b1c77* (2017-01-17 05:46 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Nehalem)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.9.1 (ORCJIT, nehalem)

[mauro3]

Seems to be related to the parameter which makes typeof(AbstractArray)==UnionAll:

julia> subtypes(Integer)
4-element Array{DataType,1}:
 BigInt  
 Bool    
 Signed  
 Unsigned

julia> subtypes(AbstractArray)
ERROR: MethodError: no method matching subtypes(::Type{AbstractArray})
Closest candidates are:
  subtypes(::Module, ::DataType) at reflection.jl:316
  subtypes(::DataType) at reflection.jl:333

Other regressions/problems in reflection.jl are Base.datatype_name, datatype_module,

[mauro3]

I tried to fix this but could not figure out how to redefine:

datatype_name(t::DataType) = t.name.name

to work with UnionAll-abstract types. Anyway, here the test-case to save someone a few keystrokes:

# Issue #20086
@test subtypes(Integer) == Type[BigInt, Bool, Signed, Unsigned]
abstract A212323{T}
immutable B212323{T} <: A212323{T} end
@test subtypes(A212323) == Type[B212323]
@test subtypes(A212323{Int}) == Type[B212323{Int}]

[tkelman]

xref attempt at #20084

[ghost]

reopened #20084, but it is not very pretty, somebody should do it better.