Revert "run inference in generated function (#76)"

CHANGELOG.md

@@ -1,5 +1,9 @@
 # News
 
+## v0.6.7 - 2024-01-02
+
+- Fix stack overflow errors by reverting the changes introduced in v0.6.6.
+
 ## v0.6.6 - 2023-10-08
 
 - Significantly improved performance on Julia 1.10 and newer by more precise inference of slot types.

Project.toml

@@ -5,7 +5,7 @@ license = "MIT"
 desc = "C# sharp style generators a.k.a. semi-coroutines for Julia."
 authors = ["Ben Lauwens <ben.lauwens@gmail.com>"]
 repo = "https://github.com/BenLauwens/ResumableFunctions.jl.git"
-version = "0.6.6"
+version = "0.6.7"
 
 [deps]
 MacroTools = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"

src/macro.jl

@@ -39,18 +39,15 @@ macro resumable(expr::Expr)
   func_def[:body] = postwalk(transform_arg_yieldfrom, func_def[:body])
   func_def[:body] = postwalk(transform_yieldfrom, func_def[:body])
   func_def[:body] = postwalk(x->transform_for(x, ui8), func_def[:body])
-  inferfn, slots = get_slots(copy(func_def), arg_dict, __module__)
+  slots = get_slots(copy(func_def), arg_dict, __module__)
   type_name = gensym(Symbol(func_def[:name], :_FSMI))
   constr_def = copy(func_def)
-  slot_T = [gensym(s) for s in keys(slots)]
-  slot_T_sub = [:($k <: $v) for (k, v) in zip(slot_T, values(slots))]
-  struct_name = :($type_name{$(func_def[:whereparams]...), $(slot_T_sub...)} <: ResumableFunctions.FiniteStateMachineIterator{$rtype})
-  constr_def[:whereparams] = (func_def[:whereparams]..., slot_T_sub...)
-  # if there are no where or slot type parameters, we need to use the bare type
-  if isempty(params) && isempty(slot_T)
+  if isempty(params)
+    struct_name = :($type_name <: ResumableFunctions.FiniteStateMachineIterator{$rtype})
     constr_def[:name] = :($type_name)
   else
-    constr_def[:name] = :($type_name{$(params...), $(slot_T...)})
+    struct_name = :($type_name{$(func_def[:whereparams]...)} <: ResumableFunctions.FiniteStateMachineIterator{$rtype})
+    constr_def[:name] = :($type_name{$(params...)})
   end
   constr_def[:args] = tuple()
   constr_def[:kwargs] = tuple()
@@ -60,44 +57,32 @@ macro resumable(expr::Expr)
     fsmi._state = 0x00
     fsmi
   end
-  # the bare/fallback version of the constructor supplies default slot type parameters
-  # we only need to define this if there there are actually slot defaults to be filled
-  if !isempty(slot_T)
-    bareconstr_def = copy(constr_def)
-    if isempty(params)
-      bareconstr_def[:name] = :($type_name)
-    else
-      bareconstr_def[:name] = :($type_name{$(params...)})
-    end
-    bareconstr_def[:whereparams] = func_def[:whereparams]
-    bareconstr_def[:body] = :($(bareconstr_def[:name]){$(values(slots)...)}())
-    bareconst_expr = combinedef(bareconstr_def) |> flatten
-  else
-    bareconst_expr = nothing
-  end
   constr_expr = combinedef(constr_def) |> flatten
   type_expr = :(
     mutable struct $struct_name
       _state :: UInt8
-      $((:($slotname :: $slottype) for (slotname, slottype) in zip(keys(slots), slot_T))...)
+      $((:($slotname :: $slottype) for (slotname, slottype) in slots)...)
       $(constr_expr)
-      $(bareconst_expr)
     end
   )
   @debug type_expr|>MacroTools.striplines
   call_def = copy(func_def)
-  call_def[:rtype] = nothing
   if isempty(params)
-    fsmi_name = type_name
+    call_def[:rtype] = nothing
+    call_def[:body] = quote
+      fsmi = $type_name()
+      $((arg !== Symbol("_") ? :(fsmi.$arg = $arg) : nothing for arg in args)...)
+      $((:(fsmi.$arg = $arg) for arg in kwargs)...)
+      fsmi
+    end
   else
-    fsmi_name = :($type_name{$(params...)})
-  end
-  fwd_args, fwd_kwargs = forward_args(call_def)
-  call_def[:body] = quote
-    fsmi = ResumableFunctions.typed_fsmi($fsmi_name, $inferfn, $(fwd_args...), $(fwd_kwargs...))
-    $((arg !== Symbol("_") ? :(fsmi.$arg = $arg) : nothing for arg in args)...)
-    $((:(fsmi.$arg = $arg) for arg in kwargs)...)
-    fsmi
+    call_def[:rtype] = nothing
+    call_def[:body] = quote
+      fsmi = $type_name{$(params...)}()
+      $((arg !== Symbol("_") ? :(fsmi.$arg = $arg) : nothing for arg in args)...)
+      $((:(fsmi.$arg = $arg) for arg in kwargs)...)
+      fsmi
+    end
   end
   call_expr = combinedef(call_def) |> flatten
   @debug call_expr|>MacroTools.striplines

src/transforms.jl

@@ -100,7 +100,7 @@ end
 """
 Function that replaces a variable `x` in an expression by `_fsmi.x` where `x` is a known slot.
 """
-function transform_slots(expr, symbols)
+function transform_slots(expr, symbols::Base.KeySet{Symbol, Dict{Symbol,Any}})
   expr isa Expr || return expr
   expr.head === :let && return transform_slots_let(expr, symbols)
   for i in 1:length(expr.args)
@@ -114,7 +114,7 @@ end
 """
 Function that handles `let` block
 """
-function transform_slots_let(expr::Expr, symbols)
+function transform_slots_let(expr::Expr, symbols::Base.KeySet{Symbol, Dict{Symbol,Any}})
   @capture(expr, let vars_; body_ end)
   locals = Set{Symbol}()
   (isa(vars, Expr) && vars.head==:(=))  || error("@resumable currently supports only single variable declarations in let blocks, i.e. only let blocks exactly of the form `let i=j; ...; end`. If you need multiple variables, please submit an issue on the issue tracker and consider contributing a patch.")
@@ -247,16 +247,14 @@ end
 """
 Function that replaces a `@yield ret` or `@yield` statement with
 ```julia
-  Base.inferencebarrier(ret)
+  return ret
 ```
-This version is used for inference only.
-It makes sure that `val = @yield ret` is inferred as `Any` rather than `typeof(ret)`.
 """
 function transform_yield(expr)
   _is_yield(expr) || return expr
   ret = length(expr.args) > 2 ? expr.args[3:end] : [nothing]
   quote
-    Base.inferencebarrier($(ret...))
+    $(ret...)
   end
 end
 

src/utils.jl

@@ -28,71 +28,42 @@ function get_args(func_def::Dict)
   arg_list, kwarg_list, arg_dict
 end
 
-"""
-Takes a function definition and returns the expressions needed to forward the arguments to an inner function.
-For example `function foo(a, ::Int, c...; x, y=1, z...)` will
-1. moodify the function to `gensym()` nameless arguments
-2. return `(:a, gensym(), :(c...)), (:x, :y, :(z...)))`
-"""
-function forward_args(func_def)
-  args = []
-  map!(func_def[:args], func_def[:args]) do arg
-    name, type, splat, default = splitarg(arg)
-    name = something(name, gensym())
-    if splat
-      push!(args, :($name...))
-    else
-      push!(args, name)
-    end
-    combinearg(name, type, splat, default)
-  end
-  kwargs = []
-  for arg in func_def[:kwargs]
-    name, type, splat, default = splitarg(arg)
-    if splat
-      push!(kwargs, :($name...))
-    else
-      push!(kwargs, name)
-    end
-  end
-  args, kwargs
-end
-
-const unused = (Symbol("#temp#"), Symbol("_"), Symbol(""), Symbol("#unused#"), Symbol("#self#"))
-
 """
 Function returning the slots of a function definition
 """
-function get_slots(func_def::Dict, args::Dict{Symbol, Any}, mod::Module)
+function get_slots(func_def::Dict, args::Dict{Symbol, Any}, mod::Module) :: Dict{Symbol, Any}
   slots = Dict{Symbol, Any}()
   func_def[:name] = gensym()
   func_def[:args] = (func_def[:args]..., func_def[:kwargs]...)
   func_def[:kwargs] = []
-  # replace yield with inference barrier
+  body = func_def[:body]
   func_def[:body] = postwalk(transform_yield, func_def[:body])
-  # collect items to skip
   nosaves = Set{Symbol}()
   func_def[:body] = postwalk(x->transform_nosave(x, nosaves), func_def[:body])
-  # eval function
   func_expr = combinedef(func_def) |> flatten
   @eval(mod, @noinline $func_expr)
-  # get typed code
   codeinfos = @eval(mod, code_typed($(func_def[:name]), Tuple; optimize=false))
-  # extract slot names and types
   for codeinfo in codeinfos
     for (name, type) in collect(zip(codeinfo.first.slotnames, codeinfo.first.slottypes))
-      name ∉ nosaves && name ∉ unused && (slots[name] = Union{type, get(slots, name, Union{})})
+      name ∉ nosaves && (slots[name] = type)
     end
   end
-  # remove `catch exc` statements
+  for (argname, argtype) in args
+    slots[argname] = argtype
+  end
   postwalk(x->remove_catch_exc(x, slots), func_def[:body])
-  # set error branches to Any
+  postwalk(x->make_arg_any(x, slots), body)
   for (key, val) in slots
     if val === Union{}
       slots[key] = Any
     end
   end
-  return func_def[:name], slots
+  delete!(slots, Symbol("#temp#"))
+  delete!(slots, Symbol("_"))
+  delete!(slots, Symbol(""))
+  delete!(slots, Symbol("#unused#"))
+  delete!(slots, Symbol("#self#"))
+  slots
 end
 
 """
@@ -103,6 +74,16 @@ function remove_catch_exc(expr, slots::Dict{Symbol, Any})
   expr
 end
 
+"""
+Function changing the type of a slot `arg` of a `arg = @yield ret` or `arg = @yield` statement to `Any`.
+"""
+function make_arg_any(expr, slots::Dict{Symbol, Any})
+  @capture(expr, arg_ = ex_) || return expr
+  _is_yield(ex) || return expr
+  slots[arg] = Any
+  expr
+end
+
 struct IteratorReturn{T}
   value :: T
   IteratorReturn(value) = new{typeof(value)}(value)
@@ -126,75 +107,3 @@ end
   isnothing(ret) && return IteratorReturn(nothing)
   ret
 end
-
-# this is similar to code_typed but it considers the world age
-function code_typed_by_type(@nospecialize(tt::Type);
-                            optimize::Bool=true,
-                            world::UInt=Base.get_world_counter(),
-                            interp::Core.Compiler.AbstractInterpreter=Core.Compiler.NativeInterpreter(world))
-    tt = Base.to_tuple_type(tt)
-    # look up the method
-    match, valid_worlds = Core.Compiler.findsup(tt, Core.Compiler.InternalMethodTable(world))
-    # run inference, normally not allowed in generated functions
-    frame = Core.Compiler.typeinf_frame(interp, match.method, match.spec_types, match.sparams, optimize)
-    frame === nothing && error("inference failed")
-    valid_worlds = Core.Compiler.intersect(valid_worlds, frame.valid_worlds)
-    return frame.linfo, frame.src, valid_worlds
-end
-
-function fsmi_generator(world::UInt, source::LineNumberNode, passtype, fsmitype::Type{Type{T}}, fargtypes) where T
-    @nospecialize
-    # get typed code of the inference function evaluated in get_slots
-    # but this time with concrete argument types
-    tt = Base.to_tuple_type(fargtypes)
-    mi, ci, valid_worlds = try
-      code_typed_by_type(tt; world, optimize=false)
-    catch err # inference failed, return generic type
-      Core.println(err)
-      slots = fieldtypes(T)[2:end]
-      stub = Core.GeneratedFunctionStub(identity, Core.svec(:pass, :fsmi, :fargs), Core.svec())
-      if isempty(slots)
-        return stub(world, source, :(return $T()))
-      else
-        return stub(world, source, :(return $T{$(slots...)}()))
-      end
-    end
-    min_world = valid_worlds.min_world
-    max_world = valid_worlds.max_world
-    # extract slot types
-    cislots = Dict{Symbol, Any}()
-    for (name, type) in collect(zip(ci.slotnames, ci.slottypes))
-      # take care to widen types that are unstable or Const
-      type = Core.Compiler.widenconst(type)
-      cislots[name] = Union{type, get(cislots, name, Union{})}
-    end
-    slots = map(slot->get(cislots, slot, Any), fieldnames(T)[2:end])
-    # generate code to instantiate the concrete type
-    stub = Core.GeneratedFunctionStub(identity, Core.svec(:pass, :fsmi, :fargs), Core.svec())
-    if isempty(slots)
-      exprs = stub(world, source, :(return $T()))
-    else
-      exprs = stub(world, source, :(return $T{$(slots...)}()))
-    end
-    # lower codeinfo to pass world age and invalidation edges
-    ci = ccall(:jl_expand_and_resolve, Any, (Any, Any, Any), exprs, passtype.name.module, Core.svec())
-    ci.min_world = min_world
-    ci.max_world = max_world
-    ci.edges = Core.MethodInstance[mi]
-    return ci
-end
-
-# JuliaLang/julia#48611: world age is exposed to generated functions, and should be used
-if VERSION >= v"1.10.0-DEV.873"
-  # This is like @generated, but it receives the world age of the caller
-  # which we need to do inference safely and correctly
-  @eval function typed_fsmi(fsmi, fargs...)
-      $(Expr(:meta, :generated_only))
-      $(Expr(:meta, :generated, fsmi_generator))
-  end
-else
-  # runtime fallback function that uses the fallback constructor with generic slot types
-  function typed_fsmi(fsmi::Type{T}, fargs...)::T where T
-    return T()
-  end
-end

test/test_jet.jl

@@ -22,10 +22,10 @@ end
     rep = report_package("ResumableFunctions";
         report_pass=MayThrowIsOk(),
         ignored_modules=(
-            Core.Compiler,
+
         )
     )
     @show rep
-    @test length(JET.get_reports(rep)) <= 8
+    @test length(JET.get_reports(rep)) <= 5
     @test_broken length(JET.get_reports(rep)) == 0
 end

test/test_main.jl

@@ -225,5 +225,5 @@ end
 end
 
 @testset "test_unstable" begin
-  @test collect(test_unstable(3)) == ["number 1", "number 2", "number 3"]
+  @test_broken collect(test_unstable(3)) == ["number 1", "number 2", "number 3"]
 end

test/test_performance.jl

@@ -32,5 +32,5 @@ end
 if VERSION >= v"1.10.0-DEV.873"
   cs = cumsum(1:1000)
   @allocated cs() # shake out the compilation overhead
-  @test (@allocated cs())==0
+  @test_broken (@allocated cs())==0
 end