reflection: use a real world for lookups (#43695)

Author: vtjnash

base/reflection.jl

@@ -980,7 +980,7 @@ function methods(@nospecialize(f), @nospecialize(t),
         throw(ArgumentError("argument is not a generic function"))
     end
     t = to_tuple_type(t)
-    world = typemax(UInt)
+    world = get_world_counter()
     # Lack of specialization => a comprehension triggers too many invalidations via _collect, so collect the methods manually
     ms = Method[]
     for m in _methods(f, t, -1, world)::Vector
@@ -995,7 +995,7 @@ methods(f::Core.Builtin) = MethodList(Method[], typeof(f).name.mt)
 
 function methods_including_ambiguous(@nospecialize(f), @nospecialize(t))
     tt = signature_type(f, t)
-    world = typemax(UInt)
+    world = get_world_counter()
     min = RefValue{UInt}(typemin(UInt))
     max = RefValue{UInt}(typemax(UInt))
     ms = _methods_by_ftype(tt, nothing, -1, world, true, min, max, Ptr{Int32}(C_NULL))
@@ -1069,7 +1069,7 @@ _uncompressed_ir(ci::Core.CodeInstance, s::Array{UInt8,1}) = ccall(:jl_uncompres
 const uncompressed_ast = uncompressed_ir
 const _uncompressed_ast = _uncompressed_ir
 
-function method_instances(@nospecialize(f), @nospecialize(t), world::UInt = typemax(UInt))
+function method_instances(@nospecialize(f), @nospecialize(t), world::UInt=get_world_counter())
     tt = signature_type(f, t)
     results = Core.MethodInstance[]
     for match in _methods_by_ftype(tt, -1, world)::Vector
@@ -1429,7 +1429,7 @@ function parentmodule(@nospecialize(f), @nospecialize(types))
 end
 
 """
-    hasmethod(f, t::Type{<:Tuple}[, kwnames]; world=typemax(UInt)) -> Bool
+    hasmethod(f, t::Type{<:Tuple}[, kwnames]; world=get_world_counter()) -> Bool
 
 Determine whether the given generic function has a method matching the given
 `Tuple` of argument types with the upper bound of world age given by `world`.
@@ -1464,13 +1464,13 @@ julia> hasmethod(g, Tuple{}, (:a, :b, :c, :d))  # g accepts arbitrary kwargs
 true
 ```
 """
-function hasmethod(@nospecialize(f), @nospecialize(t); world=typemax(UInt))
+function hasmethod(@nospecialize(f), @nospecialize(t); world::UInt=get_world_counter())
     t = to_tuple_type(t)
     t = signature_type(f, t)
     return ccall(:jl_gf_invoke_lookup, Any, (Any, UInt), t, world) !== nothing
 end
 
-function hasmethod(@nospecialize(f), @nospecialize(t), kwnames::Tuple{Vararg{Symbol}}; world=typemax(UInt))
+function hasmethod(@nospecialize(f), @nospecialize(t), kwnames::Tuple{Vararg{Symbol}}; world::UInt=get_world_counter())
     # TODO: this appears to be doing the wrong queries
     hasmethod(f, t, world=world) || return false
     isempty(kwnames) && return true
@@ -1501,7 +1501,7 @@ function bodyfunction(basemethod::Method)
     #   %1 = mkw(kwvalues..., #self#, args...)
     #        return %1
     # where `mkw` is the name of the "active" keyword body-function.
-    ast = Base.uncompressed_ast(basemethod)
+    ast = uncompressed_ast(basemethod)
     f = nothing
     if isa(ast, Core.CodeInfo) && length(ast.code) >= 2
         callexpr = ast.code[end-1]
@@ -1570,10 +1570,11 @@ function isambiguous(m1::Method, m2::Method; ambiguous_bottom::Bool=false)
         if !ambiguous_bottom
             has_bottom_parameter(ti) && return false
         end
+        world = get_world_counter()
         min = UInt[typemin(UInt)]
         max = UInt[typemax(UInt)]
         has_ambig = Int32[0]
-        ms = _methods_by_ftype(ti, nothing, -1, typemax(UInt), true, min, max, has_ambig)::Vector
+        ms = _methods_by_ftype(ti, nothing, -1, world, true, min, max, has_ambig)::Vector
         has_ambig[] == 0 && return false
         if !ambiguous_bottom
             filter!(ms) do m::Core.MethodMatch

stdlib/InteractiveUtils/src/codeview.jl

@@ -149,7 +149,7 @@ function _dump_function(@nospecialize(f), @nospecialize(t), native::Bool, wrappe
         throw(ArgumentError("argument is not a generic function"))
     end
     # get the MethodInstance for the method match
-    world = typemax(UInt)
+    world = Base.get_world_counter()
     match = Base._which(signature_type(f, t), world)
     linfo = Core.Compiler.specialize_method(match)
     # get the code for it

stdlib/Test/src/Test.jl

@@ -1704,9 +1704,10 @@ function detect_ambiguities(mods::Module...;
     function examine(mt::Core.MethodTable)
         for m in Base.MethodList(mt)
             is_in_mods(m.module, recursive, mods) || continue
-            ambig = Int32[0]
-            ms = Base._methods_by_ftype(m.sig, nothing, -1, typemax(UInt), true, UInt[typemin(UInt)], UInt[typemax(UInt)], ambig)
-            ambig[1] == 0 && continue
+            world = Base.get_world_counter()
+            ambig = Ref{Int32}(0)
+            ms = Base._methods_by_ftype(m.sig, nothing, -1, world, true, Ref(typemin(UInt)), Ref(typemax(UInt)), ambig)
+            ambig[] == 0 && continue
             isa(ms, Bool) && continue
             for match2 in ms
                 match2 = match2::Core.MethodMatch
@@ -1761,7 +1762,8 @@ function detect_unbound_args(mods...;
             if Base.isvatuple(tuple_sig)
                 params = tuple_sig.parameters[1:(end - 1)]
                 tuple_sig = Base.rewrap_unionall(Tuple{params...}, m.sig)
-                mf = ccall(:jl_gf_invoke_lookup, Any, (Any, UInt), tuple_sig, typemax(UInt))
+                world = Base.get_world_counter()
+                mf = ccall(:jl_gf_invoke_lookup, Any, (Any, UInt), tuple_sig, world)
                 if mf !== nothing && mf !== m && mf.sig <: tuple_sig
                     continue
                 end

test/compiler/contextual.jl

@@ -159,13 +159,13 @@ end
 
 end
 
-methods = Base._methods_by_ftype(Tuple{typeof(sin), Float64}, nothing, 1, typemax(UInt))
+methods = Base._methods_by_ftype(Tuple{typeof(sin), Float64}, nothing, 1, Base.get_world_counter())
 @test only(methods).method.module === Base.Math
 
-methods = Base._methods_by_ftype(Tuple{typeof(sin), Float64}, OverlayModule.mt, 1, typemax(UInt))
+methods = Base._methods_by_ftype(Tuple{typeof(sin), Float64}, OverlayModule.mt, 1, Base.get_world_counter())
 @test only(methods).method.module === OverlayModule
 
-methods = Base._methods_by_ftype(Tuple{typeof(sin), Int}, OverlayModule.mt, 1, typemax(UInt))
+methods = Base._methods_by_ftype(Tuple{typeof(sin), Int}, OverlayModule.mt, 1, Base.get_world_counter())
 @test isempty(methods)
 
 # precompilation

test/compiler/inference.jl

@@ -1232,7 +1232,7 @@ function get_linfo(@nospecialize(f), @nospecialize(t))
         throw(ArgumentError("argument is not a generic function"))
     end
     # get the MethodInstance for the method match
-    match = Base._which(Base.signature_type(f, t), typemax(UInt))
+    match = Base._which(Base.signature_type(f, t), Base.get_world_counter())
     precompile(match.spec_types)
     return Core.Compiler.specialize_method(match)
 end

test/compiler/validation.jl

@@ -19,7 +19,7 @@ function f22938(a, b, x...)
 end
 
 msig = Tuple{typeof(f22938),Int,Int,Int,Int}
-world = typemax(UInt)
+world = Base.get_world_counter()
 match = Base._methods_by_ftype(msig, -1, world)[]
 mi = Core.Compiler.specialize_method(match)
 c0 = Core.Compiler.retrieve_code_info(mi)