Skip to content

Commit

Permalink
inference: bail from const-prop if const-prop fails (#42112)
Browse files Browse the repository at this point in the history
Otherwise we can end up in an infinite cycle of attempting
const-prop, and that failing. Also handle `Varargs` in method-lookup
matching, which was the cause for which we could not compute the
const-prop signature.

Fixes #42097

(cherry picked from commit 3a4198e)
  • Loading branch information
vtjnash authored and KristofferC committed Sep 8, 2021
1 parent aa206b6 commit 886b922
Show file tree
Hide file tree
Showing 3 changed files with 29 additions and 16 deletions.
4 changes: 4 additions & 0 deletions base/compiler/abstractinterpretation.jl
Original file line number Diff line number Diff line change
Expand Up @@ -510,6 +510,10 @@ function abstract_call_method_with_const_args(interp::AbstractInterpreter, resul
return Any, nothing
end
inf_result = InferenceResult(mi, argtypes, 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
end
frame = InferenceState(inf_result, #=cache=#false, interp)
frame === nothing && return Any, nothing # this is probably a bad generated function (unsound), but just ignore it
frame.parent = sv
Expand Down
34 changes: 18 additions & 16 deletions base/compiler/inferenceresult.jl
Original file line number Diff line number Diff line change
Expand Up @@ -16,30 +16,32 @@ end
function matching_cache_argtypes(linfo::MethodInstance, given_argtypes::Vector, va_override)
@assert isa(linfo.def, Method) # ensure the next line works
nargs::Int = linfo.def.nargs
@assert length(given_argtypes) >= (nargs - 1)
given_argtypes = anymap(widenconditional, given_argtypes)
if va_override || linfo.def.isva
isva = va_override || linfo.def.isva
if isva || isvarargtype(given_argtypes[end])
isva_given_argtypes = Vector{Any}(undef, nargs)
for i = 1:(nargs - 1)
for i = 1:(nargs - isva)
isva_given_argtypes[i] = argtype_by_index(given_argtypes, i)
end
if length(given_argtypes) >= nargs || !isvarargtype(given_argtypes[end])
isva_given_argtypes[nargs] = tuple_tfunc(given_argtypes[nargs:end])
else
isva_given_argtypes[nargs] = tuple_tfunc(given_argtypes[end:end])
if isva
if length(given_argtypes) < nargs && isvarargtype(given_argtypes[end])
last = length(given_argtypes)
else
last = nargs
end
isva_given_argtypes[nargs] = tuple_tfunc(given_argtypes[last:end])
end
given_argtypes = isva_given_argtypes
end
@assert length(given_argtypes) == nargs
cache_argtypes, overridden_by_const = matching_cache_argtypes(linfo, nothing, va_override)
if nargs === length(given_argtypes)
for i in 1:nargs
given_argtype = given_argtypes[i]
cache_argtype = cache_argtypes[i]
if !is_argtype_match(given_argtype, cache_argtype, overridden_by_const[i])
# prefer the argtype we were given over the one computed from `linfo`
cache_argtypes[i] = given_argtype
overridden_by_const[i] = true
end
for i in 1:nargs
given_argtype = given_argtypes[i]
cache_argtype = cache_argtypes[i]
if !is_argtype_match(given_argtype, cache_argtype, overridden_by_const[i])
# prefer the argtype we were given over the one computed from `linfo`
cache_argtypes[i] = given_argtype
overridden_by_const[i] = true
end
end
return cache_argtypes, overridden_by_const
Expand Down
7 changes: 7 additions & 0 deletions test/compiler/inference.jl
Original file line number Diff line number Diff line change
Expand Up @@ -3499,3 +3499,10 @@ end
end
return x
end) === Union{Int, Float64, Char}

# issue #42097
struct Foo42097{F} end
Foo42097(f::F, args) where {F} = Foo42097{F}()
Foo42097(A) = Foo42097(Base.inferencebarrier(+), Base.inferencebarrier(1)...)
foo42097() = Foo42097([1]...)
@test foo42097() isa Foo42097{typeof(+)}

0 comments on commit 886b922

Please sign in to comment.