Merge pull request #49664 from JuliaLang/jn/ml-matches-rewritten

reorder ml-matches to avoid catastrophic performance case

Author: vtjnash

doc/src/manual/methods.md

@@ -322,10 +322,10 @@ julia> g(2.0, 3.0)
 ERROR: MethodError: g(::Float64, ::Float64) is ambiguous.
 
 Candidates:
-  g(x::Float64, y)
-    @ Main none:1
   g(x, y::Float64)
     @ Main none:1
+  g(x::Float64, y)
+    @ Main none:1
 
 Possible fix, define
   g(::Float64, ::Float64)

src/gf.c

@@ -811,7 +811,7 @@ end
 let s = "CompletionFoo.test11(3, 4,"
     c, r, res = test_complete(s)
     @test !res
-    @test length(c) == 4
+    @test length(c) == 2
     @test any(str->occursin("test11(x::$Int, y::$Int, z)", str), c)
     @test any(str->occursin("test11(::Any, ::Any, s::String)", str), c)
 end

stdlib/REPL/test/replcompletions.jl

@@ -378,6 +378,17 @@ let ambig = Ref{Int32}(0)
     @test ambig[] == 1
 end
 
+fnoambig(::Int,::Int) = 1
+fnoambig(::Int,::Any) = 2
+fnoambig(::Any,::Int) = 3
+fnoambig(::Any,::Any) = 4
+let has_ambig = Ref(Int32(0))
+    ms = Base._methods_by_ftype(Tuple{typeof(fnoambig), Any, Any}, nothing, 4, Base.get_world_counter(), false, Ref(typemin(UInt)), Ref(typemax(UInt)), has_ambig)
+    @test ms isa Vector
+    @test length(ms) == 4
+    @test has_ambig[] == 0
+end
+
 # issue #11407
 f11407(::Dict{K,V}, ::Dict{Any,V}) where {K,V} = 1
 f11407(::Dict{K,V}, ::Dict{K,Any}) where {K,V} = 2

test/ambiguous.jl

@@ -43,8 +43,8 @@ end |> !Core.Compiler.is_nonoverlayed
 end |> !Core.Compiler.is_nonoverlayed
 
 # account for overlay possibility in unanalyzed matching method
-callstrange(::Nothing) = Core.compilerbarrier(:type, nothing) # trigger inference bail out
 callstrange(::Float64) = strangesin(x)
+callstrange(::Nothing) = Core.compilerbarrier(:type, nothing) # trigger inference bail out
 callstrange_entry(x) = callstrange(x) # needs to be defined here because of world age
 let interp = MTOverlayInterp(Set{Any}())
     matches = Core.Compiler.findall(Tuple{typeof(callstrange),Any}, Core.Compiler.method_table(interp)).matches

test/compiler/AbstractInterpreter.jl

@@ -92,8 +92,15 @@ method_c2(x::Int32, y::Float64) = true
 method_c2(x::Int32, y::Int32, z::Int32) = true
 method_c2(x::T, y::T, z::T) where {T<:Real} = true
 
-Base.show_method_candidates(buf, Base.MethodError(method_c2,(1., 1., 2)))
-@test occursin( "\n\nClosest candidates are:\n  method_c2(!Matched::Int32, ::Float64, ::Any...)$cmod$cfile$(c2line+2)\n  method_c2(::T, ::T, !Matched::T) where T<:Real$cmod$cfile$(c2line+5)\n  method_c2(!Matched::Int32, ::Any...)$cmod$cfile$(c2line+1)\n  ...\n", String(take!(buf)))
+let s
+    Base.show_method_candidates(buf, Base.MethodError(method_c2, (1., 1., 2)))
+    s = String(take!(buf))
+    @test occursin("\n\nClosest candidates are:\n  ", s)
+    @test occursin("\n  method_c2(!Matched::Int32, ::Float64, ::Any...)$cmod$cfile$(c2line+2)\n  ", s)
+    @test occursin("\n  method_c2(::T, ::T, !Matched::T) where T<:Real$cmod$cfile$(c2line+5)\n  ", s)
+    @test occursin("\n  method_c2(!Matched::Int32, ::Any...)$cmod$cfile$(c2line+1)\n  ", s)
+    @test occursin("\n  ...\n", s)
+end
 
 c3line = @__LINE__() + 1
 method_c3(x::Float64, y::Float64) = true

test/errorshow.jl

@@ -547,7 +547,7 @@ let
 end
 
 # code_typed_by_type
-@test Base.code_typed_by_type(Tuple{Type{<:Val}})[1][2] == Val
+@test Base.code_typed_by_type(Tuple{Type{<:Val}})[2][2] == Val
 @test Base.code_typed_by_type(Tuple{typeof(sin), Float64})[1][2] === Float64
 
 # New reflection methods in 0.6