From 401b724fbbf5a59cc47cb624b01d563517857234 Mon Sep 17 00:00:00 2001
From: Martin Holters <martin.holters@hsu-hh.de>
Date: Tue, 20 Jun 2017 08:22:56 +0200
Subject: [PATCH] Don't special-case inference of splatting ::Any parameters
 (#22364)

---
 base/inference.jl | 31 ++++++++++---------------------
 test/inference.jl |  7 +++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/base/inference.jl b/base/inference.jl
index 549e7b6b4b895..db09e8d35ea17 100644
--- a/base/inference.jl
+++ b/base/inference.jl
@@ -1879,30 +1879,19 @@ function abstract_apply(aft::ANY, fargs::Vector{Any}, aargtypes::Vector{Any}, vt
     splitunions = 1 < countunionsplit(aargtypes) <= sv.params.MAX_APPLY_UNION_ENUM
     ctypes = Any[Any[aft]]
     for i = 1:nargs
-        if aargtypes[i] === Any
-            # bail out completely and infer as f(::Any...)
-            # instead could infer the precise types for the types up to this point and just append a Vararg{Any}
-            # (by just using the normal logic from below), but that makes the time of the subarray test explode
-            push!(ctypes[1], Vararg{Any})
-            break
-        end
-    end
-    if length(ctypes[1]) == 1
-        for i = 1:nargs
-            ctypes´ = []
-            for ti in (splitunions ? uniontypes(aargtypes[i]) : Any[aargtypes[i]])
-                cti = precise_container_type(fargs[i], ti, vtypes, sv)
-                for ct in ctypes
-                    if !isempty(ct) && isvarargtype(ct[end])
-                        tail = tuple_tail_elem(unwrapva(ct[end]), cti)
-                        push!(ctypes´, push!(ct[1:(end - 1)], tail))
-                    else
-                        push!(ctypes´, append_any(ct, cti))
-                    end
+        ctypes´ = []
+        for ti in (splitunions ? uniontypes(aargtypes[i]) : Any[aargtypes[i]])
+            cti = precise_container_type(fargs[i], ti, vtypes, sv)
+            for ct in ctypes
+                if !isempty(ct) && isvarargtype(ct[end])
+                    tail = tuple_tail_elem(unwrapva(ct[end]), cti)
+                    push!(ctypes´, push!(ct[1:(end - 1)], tail))
+                else
+                    push!(ctypes´, append_any(ct, cti))
                 end
             end
-            ctypes = ctypes´
         end
+        ctypes = ctypes´
     end
     for ct in ctypes
         if length(ct) > sv.params.MAX_TUPLETYPE_LEN
diff --git a/test/inference.jl b/test/inference.jl
index 360b262ee5c5e..54574454b765f 100644
--- a/test/inference.jl
+++ b/test/inference.jl
@@ -949,3 +949,10 @@ copy_dims_pair(out, dim::Int, tail...) =  copy_dims_out(out => dim, tail...)
 copy_dims_pair(out, dim::Colon, tail...) = copy_dims_out(out => dim, tail...)
 @test Base.return_types(copy_dims_pair, (Tuple{}, Vararg{Union{Int,Colon}})) == Any[Tuple{}, Tuple{}, Tuple{}]
 @test all(m -> 5 < count_specializations(m) < 25, methods(copy_dims_out))
+
+# splatting an ::Any should still allow inference to use types of parameters preceding it
+f22364(::Int, ::Any...) = 0
+f22364(::String, ::Any...) = 0.0
+g22364(x) = f22364(x, Any[[]][1]...)
+@test @inferred(g22364(1)) === 0
+@test @inferred(g22364("1")) === 0.0