fix wrong assertion, just propagate Bottom instead

JuliaLang · Oct 21, 2021 · c641d85 · c641d85
1 parent 4ef88d2
commit c641d85
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Showing 3 changed files with 14 additions and 16 deletions.
diff --git a/base/compiler/abstractinterpretation.jl b/base/compiler/abstractinterpretation.jl
@@ -547,7 +547,7 @@ function abstract_call_method_with_const_args(interp::AbstractInterpreter, resul
                 return nothing
             end
         end
-        inf_result = InferenceResult(mi; arginfo, va_override)
+        inf_result = InferenceResult(mi, arginfo, va_override)
         if !any(inf_result.overridden_by_const)
             add_remark!(interp, sv, "[constprop] Could not handle constant info in matching_cache_argtypes")
             return nothing

diff --git a/base/compiler/inferenceresult.jl b/base/compiler/inferenceresult.jl
@@ -24,6 +24,7 @@ function matching_cache_argtypes(
     linfo::MethodInstance, (; fargs, argtypes)::ArgInfo, va_override::Bool)
     @assert isa(linfo.def, Method) # ensure the next line works
     nargs::Int = linfo.def.nargs
+    cache_argtypes, overridden_by_const = matching_cache_argtypes(linfo, nothing, va_override)
     given_argtypes = Vector{Any}(undef, length(argtypes))
     local condargs = nothing
     for i in 1:length(argtypes)
@@ -33,20 +34,18 @@ function matching_cache_argtypes(
             cnd = argtype
             slotid = find_constrained_arg(cnd, fargs)
             if slotid !== nothing
-                if condargs === nothing
-                    condargs = Tuple{Int,Int}[]
-                end
-                # using union-split signature, we may be able to narrow down `Conditional` to `Const`
-                vtype = tmeet(cnd.vtype, widenconst(argtypes[slotid]))
-                elsetype = tmeet(cnd.elsetype, widenconst(argtypes[slotid]))
-                if vtype === Bottom
-                    given_argtypes[i] = Const(false)
-                    # union-split should never find a more precise information about `fargs[slotid]` than `Conditional`,
-                    # otherwise there should have been a bug around `Conditional` construction or maintainance
-                    @assert elsetype !== Bottom "invalid Conditional element"
-                elseif elsetype === Bottom
-                    given_argtypes[i] = Const(true)
+                # using union-split signature, we may be able to narrow down `Conditional`
+                sigt = widenconst(slotid > nargs ? argtypes[slotid] : cache_argtypes[slotid])
+                vtype = tmeet(cnd.vtype, sigt)
+                elsetype = tmeet(cnd.elsetype, sigt)
+                if vtype === Bottom && elsetype === Bottom
+                    # we accidentally proved this method match is impossible
+                    # TODO bail out here immediately rather than just propagating Bottom ?
+                    given_argtypes[i] = Bottom
                 else
+                    if condargs === nothing
+                        condargs = Tuple{Int,Int}[]
+                    end
                     push!(condargs, (slotid, i))
                     given_argtypes[i] = Conditional(SlotNumber(slotid), vtype, elsetype)
                 end
@@ -80,7 +79,6 @@ function matching_cache_argtypes(
         given_argtypes = isva_given_argtypes
     end
     @assert length(given_argtypes) == nargs
-    cache_argtypes, overridden_by_const = matching_cache_argtypes(linfo, nothing, va_override)
     for i in 1:nargs
         given_argtype = given_argtypes[i]
         cache_argtype = cache_argtypes[i]

diff --git a/base/compiler/types.jl b/base/compiler/types.jl
@@ -34,7 +34,7 @@ mutable struct InferenceResult
     result # ::Type, or InferenceState if WIP
     src #::Union{CodeInfo, OptimizationState, Nothing} # if inferred copy is available
     valid_worlds::WorldRange # if inference and optimization is finished
-    function InferenceResult(linfo::MethodInstance;
+    function InferenceResult(linfo::MethodInstance,
                              arginfo::Union{Nothing,ArgInfo} = nothing,
                              va_override::Bool = false)
         argtypes, overridden_by_const = matching_cache_argtypes(linfo, arginfo, va_override)