From 07ffecb2257d40db7452a3f335f3b38796272e76 Mon Sep 17 00:00:00 2001
From: Tim Holy <tim.holy@gmail.com>
Date: Sun, 23 Aug 2020 09:52:41 -0500
Subject: [PATCH] More inferrability improvements

Detected as part of my work on https://github.com/JuliaLang/julia/pull/37163
---
 src/Cthulhu.jl    | 12 ++++++++++--
 src/reflection.jl | 16 ++++++++--------
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/Cthulhu.jl b/src/Cthulhu.jl
index 9503afad..0b33f79b 100644
--- a/src/Cthulhu.jl
+++ b/src/Cthulhu.jl
@@ -7,6 +7,12 @@ using UUIDs
 using Core: MethodInstance
 const Compiler = Core.Compiler
 
+if isdefined(Base, :mapany)
+    const mapany = Base.mapany
+else
+    mapany(f, itr) = map!(f, Vector{Any}(undef, length(itr)::Int), itr)  # convenient for Expr.args
+end
+
 Base.@kwdef mutable struct CthulhuConfig
     enable_highlighter::Bool = false
     highlighter::Cmd = `pygmentize -l`
@@ -174,7 +180,9 @@ function _descend(mi::MethodInstance; iswarn::Bool, params=current_params(), opt
             callsite = callsites[cid]
 
             if callsite.info isa MultiCallInfo
-                sub_callsites = map(ci->Callsite(callsite.id, ci), callsite.info.callinfos)
+                sub_callsites = let callsite=callsite
+                    map(ci->Callsite(callsite.id, ci), callsite.info.callinfos)
+                end
                 if isempty(sub_callsites)
                     @warn "Expected multiple callsites, but found none. Please fill an issue with a reproducing example" callsite.info
                     continue
@@ -231,7 +239,7 @@ function _descend(mi::MethodInstance; iswarn::Bool, params=current_params(), opt
             id = Base.PkgId(UUID("295af30f-e4ad-537b-8983-00126c2a3abe"), "Revise")
             mod = get(Base.loaded_modules, id, nothing)
             if mod !== nothing
-                revise = getfield(mod, :revise)
+                revise = getfield(mod, :revise)::Function
                 revise()
                 mi = first_method_instance(mi.specTypes)
             end
diff --git a/src/reflection.jl b/src/reflection.jl
index 14a26ed4..c145a45d 100644
--- a/src/reflection.jl
+++ b/src/reflection.jl
@@ -38,7 +38,7 @@ function transform(::Val{:CuFunction}, callsite, callexpr, CI, mi, slottypes; pa
     return Callsite(callsite.id, CuCallInfo(callinfo(Tuple{widenconst(ft), tt.val.parameters...}, Nothing, params=params)))
 end
 
-function find_callsites(CI, mi, slottypes; params=current_params(), multichoose::Bool=false, kwargs...)
+function find_callsites(CI::Core.CodeInfo, mi::Core.MethodInstance, slottypes; params=current_params(), multichoose::Bool=false, kwargs...)
     sptypes = sptypes_from_meth_instance(mi)
     callsites = Callsite[]
 
@@ -87,7 +87,7 @@ function find_callsites(CI, mi, slottypes; params=current_params(), multichoose:
                 end
             elseif c.head === :call
                 rt = CI.ssavaluetypes[id]
-                types = map(arg -> widenconst(argextype(arg, CI, sptypes, slottypes)), c.args)
+                types = mapany(arg -> widenconst(argextype(arg, CI, sptypes, slottypes)), c.args)
 
                 # Look through _apply
                 ok = true
@@ -142,9 +142,9 @@ function find_callsites(CI, mi, slottypes; params=current_params(), multichoose:
                     end
                     thatcher(types[1])
                     sigs = let types=types
-                        map(ft-> [ft, types[2:end]...], fts)
+                        mapany(ft-> Any[ft, types[2:end]...], fts)
                     end
-                    cis = map(t -> callinfo(Tuple{t...}, rt, params=params), sigs)
+                    cis = CallInfo[callinfo(Tuple{t...}, rt, params=params) for t in sigs]
                     callsite = Callsite(id, MultiCallInfo(Tuple{types...}, rt, cis))
                 else
                     ft = Base.unwrap_unionall(types[1])
@@ -201,7 +201,7 @@ if isdefined(Core.Compiler, :AbstractInterpreter)
         ccall(:jl_typeinf_begin, Cvoid, ())
         result = Core.Compiler.InferenceResult(mi)
         frame = Core.Compiler.InferenceState(result, false, interp)
-        frame === nothing && return (nothing, Any)
+        frame === nothing && return (nothing, Any, Any[])
         if Compiler.typeinf(interp, frame) && run_optimizer
             oparams = Core.Compiler.OptimizationParams(interp)
             opt = Compiler.OptimizationState(frame, oparams, interp)
@@ -209,7 +209,7 @@ if isdefined(Core.Compiler, :AbstractInterpreter)
             opt.src.inferred = true
         end
         ccall(:jl_typeinf_end, Cvoid, ())
-        frame.inferred || return (nothing, Any)
+        frame.inferred || return (nothing, Any, Any[])
         return (frame.src, result.result, frame.slottypes)
     end
 else
@@ -217,14 +217,14 @@ else
         ccall(:jl_typeinf_begin, Cvoid, ())
         result = Core.Compiler.InferenceResult(mi)
         frame = Core.Compiler.InferenceState(result, false, params)
-        frame === nothing && return (nothing, Any)
+        frame === nothing && return (nothing, Any, Any[])
         if Compiler.typeinf(frame) && run_optimizer
             opt = Compiler.OptimizationState(frame)
             Compiler.optimize(opt, result.result)
             opt.src.inferred = true
         end
         ccall(:jl_typeinf_end, Cvoid, ())
-        frame.inferred || return (nothing, Any)
+        frame.inferred || return (nothing, Any, Any[])
         return (frame.src, result.result, frame.slottypes)
     end
 end