update to https://github.com/JuliaLang/julia/pull/39972

src/abstractinterpretation.jl

@@ -139,10 +139,12 @@ end
 
 function CC.abstract_call_method_with_const_args(interp::JETInterpreter, @nospecialize(rettype),
                                                  @nospecialize(f), argtypes::Vector{Any}, match::MethodMatch,
-                                                 sv::InferenceState, edgecycle::Bool)
+                                                 sv::InferenceState, edgecycle::Bool,
+                                                 va_override::Bool)
     result, inf_result = @invoke abstract_call_method_with_const_args(interp::AbstractInterpreter, @nospecialize(rettype),
                                                                       @nospecialize(f), argtypes::Vector{Any}, match::MethodMatch,
-                                                                      sv::InferenceState, edgecycle::Bool)
+                                                                      sv::InferenceState, edgecycle::Bool,
+                                                                      va_override::Bool)
 
     if isa(inf_result, InferenceResult)
         # successful constant prop', we also need to update reports

src/abstractinterpreterinterface.jl

@@ -224,11 +224,6 @@ struct AnalysisResult
     argtypes::Vector{Any}
     overridden_by_const::CC.BitVector
     cache::Vector{InferenceErrorReportCache}
-    # adapted from https://github.com/JuliaLang/julia/blob/3129a5bef56bb7216024ae606c02b413b00990e3/base/compiler/types.jl#L32-L35
-    function AnalysisResult(linfo::MethodInstance, given_argtypes::Vector{Any}, cache::Vector{InferenceErrorReportCache})
-        argtypes, overridden_by_const = matching_cache_argtypes(linfo, given_argtypes)
-        return new(linfo, argtypes, overridden_by_const, cache)
-    end
 end
 
 mutable struct JETInterpreter <: AbstractInterpreter

src/typeinfer.jl

@@ -169,7 +169,8 @@ function CC._typeinf(interp::JETInterpreter, frame::InferenceState)
 
     if !isempty(this_caches)
         if iscp
-            argtypes = frame.result.argtypes
+            result = frame.result
+            argtypes = result.argtypes
             cache = interp.cache
             @assert jet_cache_lookup(linfo, argtypes, cache) === nothing "invalid local caching $linfo, $argtypes"
             local_cache = InferenceErrorReportCache[]
@@ -178,7 +179,15 @@ function CC._typeinf(interp::JETInterpreter, frame::InferenceState)
                 # @assert first(report.st).linfo === linfo "invalid local caching"
                 cache_report!(local_cache, report)
             end
-            push!(cache, AnalysisResult(linfo, argtypes, local_cache))
+            # branching on https://github.com/JuliaLang/julia/pull/39972
+            given_argtypes, overridden_by_const = @static if VERSION ≥ v"1.7.0-DEV.705"
+                def = result.linfo.def
+                va_overwride = isa(def, Method) && def.is_for_opaque_closure
+                matching_cache_argtypes(linfo, argtypes, va_overwride)
+            else
+                matching_cache_argtypes(linfo, argtypes)
+            end
+            push!(cache, AnalysisResult(linfo, given_argtypes, overridden_by_const, local_cache))
         elseif frame.cached # only cache when `NativeInterpreter` does
             @assert !haskey(JET_GLOBAL_CACHE, linfo) || isentry "invalid global caching $linfo"
             global_cache = InferenceErrorReportCache[]

test/test_abstractinterpretation.jl

@@ -851,3 +851,17 @@ end
     interp, frame = analyze_call(m.psort!, (Vector{Int},))
     @test true
 end
+
+@static if VERSION ≥ v"1.7.0-DEV.705"
+
+@testset "opaque closure" begin
+    # can cache const prop' result with varargs
+    function oc_varargs_constprop()
+        oc = Base.Experimental.@opaque (args...)->args[1]+args[2]+arg[3] # typo on `arg[3]`
+        return Val{oc(1,2,3)}()
+    end
+    interp, = @analyze_call oc_varargs_constprop()
+    @test !isempty(interp.cache)
+end
+
+end # @static if VERSION ≥ v"1.7.0-DEV.705"