Put inference parameters in a dedicated object.

This allows overriding parameters, while reducing global state
and simplifying the API.

base/REPLCompletions.jl

@@ -285,7 +285,8 @@ function get_type_call(expr::Expr)
     length(mt) == 1 || return (Any, false)
     m = first(mt)
     # Typeinference
-    return_type = Core.Inference.typeinf_type(m[3], m[1], m[2])
+    params = Core.Inference.InferenceParams()
+    return_type = Core.Inference.typeinf_type(m[3], m[1], m[2], true, params)
     return_type === nothing && return (Any, false)
     return (return_type, true)
 end

base/inference.jl

@@ -5,11 +5,25 @@ import Core: _apply, svec, apply_type, Builtin, IntrinsicFunction, MethodInstanc
 #### parameters limiting potentially-infinite types ####
 const MAX_TYPEUNION_LEN = 3
 const MAX_TYPE_DEPTH = 7
-const MAX_TUPLETYPE_LEN = 15
-const MAX_TUPLE_DEPTH = 4
 
-const MAX_TUPLE_SPLAT = 16
-const MAX_UNION_SPLITTING = 4
+immutable InferenceParams
+    # optimization
+    inlining::Bool
+
+    # parameters limiting potentially-infinite types (configurable)
+    MAX_TUPLETYPE_LEN::Int
+    MAX_TUPLE_DEPTH::Int
+    MAX_TUPLE_SPLAT::Int
+    MAX_UNION_SPLITTING::Int
+
+    # reasonable defaults
+    InferenceParams(;inlining::Bool=inlining_enabled(),
+                    tupletype_len::Int=15, tuple_depth::Int=4,
+                    tuple_splat::Int=16, union_splitting::Int=4) =
+        new(inlining, tupletype_len,
+            tuple_depth, tuple_splat, union_splitting)
+end
+
 const UNION_SPLIT_MISMATCH_ERROR = false
 
 # alloc_elim_pass! relies on `Slot_AssignedOnce | Slot_UsedUndef` being
@@ -49,6 +63,8 @@ type InferenceState
     mod::Module
     currpc::LineNum
 
+    params::InferenceParams
+
     # info on the state of inference and the linfo
     linfo::MethodInstance # used here for the tuple (specTypes, env, Method)
     src::CodeInfo
@@ -74,14 +90,16 @@ type InferenceState
     # iteration fixed-point detection
     fixedpoint::Bool
     inworkq::Bool
-    # optimization
+
+    # TODO: put these in InferenceParams (depends on proper multi-methodcache support)
     optimize::Bool
-    inlining::Bool
     cached::Bool
+
     inferred::Bool
 
     # src is assumed to be a newly-allocated CodeInfo, that can be modified in-place to contain intermediate results
-    function InferenceState(linfo::MethodInstance, src::CodeInfo, optimize::Bool, inlining::Bool, cached::Bool)
+    function InferenceState(linfo::MethodInstance, src::CodeInfo,
+                            optimize::Bool, cached::Bool, params::InferenceParams)
         code = src.code::Array{Any,1}
         nl = label_counter(code) + 1
         toplevel = !isdefined(linfo, :def)
@@ -113,7 +131,7 @@ type InferenceState
                     end
                     s[1][la] = VarState(Tuple, false)
                 else
-                    s[1][la] = VarState(tuple_tfunc(limit_tuple_depth(tupletype_tail(atypes, la))), false)
+                    s[1][la] = VarState(tuple_tfunc(limit_tuple_depth(params, tupletype_tail(atypes, la))), false)
                 end
                 la -= 1
             end
@@ -168,12 +186,13 @@ type InferenceState
         inmodule = toplevel ? current_module() : linfo.def.module # toplevel thunks are inferred in the current module
         frame = new(
             sp, nl, inmodule, 0,
+            params,
             linfo, src, nargs, s, Union{}, W, n,
             cur_hand, handler_at, n_handlers,
             ssavalue_uses, ssavalue_init,
             ObjectIdDict(), #Dict{InferenceState, Vector{LineNum}}(),
             Vector{Tuple{InferenceState, Vector{LineNum}}}(),
-            false, false, optimize, inlining, cached, false)
+            false, false, optimize, cached, false)
         push!(active, frame)
         nactive[] += 1
         return frame
@@ -669,7 +688,7 @@ function invoke_tfunc(f::ANY, types::ANY, argtype::ANY, sv::InferenceState)
     if !isleaftype(Type{types})
         return Any
     end
-    argtype = typeintersect(types,limit_tuple_type(argtype))
+    argtype = typeintersect(types,limit_tuple_type(argtype, sv.params))
     if is(argtype,Bottom)
         return Bottom
     end
@@ -703,7 +722,7 @@ function builtin_tfunction(f::ANY, argtypes::Array{Any,1}, sv::InferenceState)
     if is(f,tuple)
         for a in argtypes
             if !isa(a, Const)
-                return tuple_tfunc(limit_tuple_depth(argtypes_to_type(argtypes)))
+                return tuple_tfunc(limit_tuple_depth(sv.params, argtypes_to_type(argtypes)))
             end
         end
         return Const(tuple(map(a->a.val, argtypes)...))
@@ -766,28 +785,28 @@ function builtin_tfunction(f::ANY, argtypes::Array{Any,1}, sv::InferenceState)
     return tf[3](argtypes...)
 end
 
-limit_tuple_depth(t::ANY) = limit_tuple_depth_(t,0)
+limit_tuple_depth(params::InferenceParams, t::ANY) = limit_tuple_depth_(params,t,0)
 
-function limit_tuple_depth_(t::ANY, d::Int)
+function limit_tuple_depth_(params::InferenceParams, t::ANY, d::Int)
     if isa(t,Union)
         # also limit within Union types.
         # may have to recur into other stuff in the future too.
-        return Union{map(x->limit_tuple_depth_(x,d+1), t.types)...}
+        return Union{map(x->limit_tuple_depth_(params,x,d+1), t.types)...}
     end
     if isa(t,TypeVar)
-        return limit_tuple_depth_(t.ub, d)
+        return limit_tuple_depth_(params, t.ub, d)
     end
     if !(isa(t,DataType) && t.name === Tuple.name)
         return t
     end
-    if d > MAX_TUPLE_DEPTH
+    if d > params.MAX_TUPLE_DEPTH
         return Tuple
     end
-    p = map(x->limit_tuple_depth_(x,d+1), t.parameters)
+    p = map(x->limit_tuple_depth_(params,x,d+1), t.parameters)
     Tuple{p...}
 end
 
-limit_tuple_type = (t::ANY) -> limit_tuple_type_n(t, MAX_TUPLETYPE_LEN)
+limit_tuple_type = (t::ANY, params::InferenceParams) -> limit_tuple_type_n(t, params.MAX_TUPLETYPE_LEN)
 
 function limit_tuple_type_n(t::ANY, lim::Int)
     p = t.parameters
@@ -802,7 +821,7 @@ end
 
 #### recursing into expression ####
 
-function abstract_call_gf_by_type(f::ANY, argtype::ANY, sv)
+function abstract_call_gf_by_type(f::ANY, argtype::ANY, sv::InferenceState)
     tm = _topmod(sv)
     # don't consider more than N methods. this trades off between
     # compiler performance and generated code performance.
@@ -811,7 +830,7 @@ function abstract_call_gf_by_type(f::ANY, argtype::ANY, sv)
     # It is important for N to be >= the number of methods in the error()
     # function, so we can still know that error() is always Bottom.
     # here I picked 4.
-    argtype = limit_tuple_type(argtype)
+    argtype = limit_tuple_type(argtype, sv.params)
     argtypes = argtype.parameters
     applicable = _methods_by_ftype(argtype, 4)
     rettype = Bottom
@@ -1006,9 +1025,10 @@ function abstract_apply(af::ANY, fargs, aargtypes::Vector{Any}, vtypes::VarTable
         # can be collapsed to a call to the applied func
         at = append_any(Any[type_typeof(af)], ctypes...)
         n = length(at)
-        if n-1 > MAX_TUPLETYPE_LEN
-            tail = foldl((a,b)->tmerge(a,unwrapva(b)), Bottom, at[MAX_TUPLETYPE_LEN+1:n])
-            at = vcat(at[1:MAX_TUPLETYPE_LEN], Any[Vararg{tail}])
+        if n-1 > sv.params.MAX_TUPLETYPE_LEN
+            tail = foldl((a,b)->tmerge(a,unwrapva(b)), Bottom,
+                         at[sv.params.MAX_TUPLETYPE_LEN+1:n])
+            at = vcat(at[1:sv.params.MAX_TUPLETYPE_LEN], Any[Vararg{tail}])
         end
         return abstract_call(af, (), at, vtypes, sv)
     end
@@ -1024,6 +1044,7 @@ function pure_eval_call(f::ANY, argtypes::ANY, atype::ANY, vtypes::VarTable, sv:
     end
 
     if f === return_type && length(argtypes) == 3
+        # NOTE: only considering calls to return_type without InferenceParams arg
         tt = argtypes[3]
         if isType(tt)
             af_argtype = tt.parameters[1]
@@ -1127,7 +1148,7 @@ function abstract_call(f::ANY, fargs, argtypes::Vector{Any}, vtypes::VarTable, s
         return Type
     end
 
-    if sv.inlining
+    if sv.params.inlining
         # need to model the special inliner for ^
         # to ensure we have added the same edge
         if isdefined(Main, :Base) &&
@@ -1520,7 +1541,8 @@ end
 
 
 # build (and start inferring) the inference frame for the linfo
-function typeinf_frame(linfo::MethodInstance, optimize::Bool, cached::Bool, caller)
+function typeinf_frame(linfo::MethodInstance, caller, optimize::Bool, cached::Bool,
+                       params::InferenceParams)
     frame = nothing
     if linfo.inInference
         # inference on this signature may be in progress,
@@ -1549,7 +1571,7 @@ function typeinf_frame(linfo::MethodInstance, optimize::Bool, cached::Bool, call
             src = get_source(linfo)
         end
         linfo.inInference = true
-        frame = InferenceState(linfo, src, optimize, inlining_enabled(), cached)
+        frame = InferenceState(linfo, src, optimize, cached, params)
     end
     frame = frame::InferenceState
 
@@ -1590,7 +1612,7 @@ function typeinf_edge(method::Method, atypes::ANY, sparams::SimpleVector, caller
             end
         end
     end
-    frame = typeinf_frame(code, true, true, caller)
+    frame = typeinf_frame(code, caller, true, true, caller.params)
     frame === nothing && return Any
     frame = frame::InferenceState
     return frame.bestguess
@@ -1599,12 +1621,14 @@ end
 #### entry points for inferring a MethodInstance given a type signature ####
 
 # compute an inferred AST and return type
-function typeinf_code(method::Method, atypes::ANY, sparams::SimpleVector, optimize::Bool, cached::Bool)
+function typeinf_code(method::Method, atypes::ANY, sparams::SimpleVector,
+                      optimize::Bool, cached::Bool, params::InferenceParams)
     code = code_for_method(method, atypes, sparams)
     code === nothing && return (nothing, Any)
-    return typeinf_code(code::MethodInstance, optimize, cached)
+    return typeinf_code(code::MethodInstance, optimize, cached, params)
 end
-function typeinf_code(linfo::MethodInstance, optimize::Bool, cached::Bool)
+function typeinf_code(linfo::MethodInstance, optimize::Bool, cached::Bool,
+                      params::InferenceParams)
     for i = 1:2 # test-and-lock-and-test
         if cached && isdefined(linfo, :inferred)
             # see if this code already exists in the cache
@@ -1635,7 +1659,7 @@ function typeinf_code(linfo::MethodInstance, optimize::Bool, cached::Bool)
         end
         i == 1 && ccall(:jl_typeinf_begin, Void, ())
     end
-    frame = typeinf_frame(linfo, optimize, cached, nothing)
+    frame = typeinf_frame(linfo, nothing, optimize, cached, params)
     ccall(:jl_typeinf_end, Void, ())
     frame === nothing && return (nothing, Any)
     frame = frame::InferenceState
@@ -1644,7 +1668,8 @@ function typeinf_code(linfo::MethodInstance, optimize::Bool, cached::Bool)
 end
 
 # compute (and cache) an inferred AST and return the inferred return type
-function typeinf_type(method::Method, atypes::ANY, sparams::SimpleVector, cached::Bool=true)
+function typeinf_type(method::Method, atypes::ANY, sparams::SimpleVector,
+                      cached::Bool, params::InferenceParams)
     code = code_for_method(method, atypes, sparams)
     code === nothing && return nothing
     code = code::MethodInstance
@@ -1661,7 +1686,7 @@ function typeinf_type(method::Method, atypes::ANY, sparams::SimpleVector, cached
         end
         i == 1 && ccall(:jl_typeinf_begin, Void, ())
     end
-    frame = typeinf_frame(code, cached, cached, nothing)
+    frame = typeinf_frame(code, nothing, cached, cached, params)
     ccall(:jl_typeinf_end, Void, ())
     frame === nothing && return nothing
     frame = frame::InferenceState
@@ -1672,13 +1697,14 @@ end
 function typeinf_ext(linfo::MethodInstance)
     if isdefined(linfo, :def)
         # method lambda - infer this specialization via the method cache
-        (code, typ) = typeinf_code(linfo, true, true)
+        (code, typ) = typeinf_code(linfo, true, true, InferenceParams())
         return code
     else
         # toplevel lambda - infer directly
         linfo.inInference = true
         ccall(:jl_typeinf_begin, Void, ())
-        frame = InferenceState(linfo, linfo.inferred::CodeInfo, true, inlining_enabled(), true)
+        frame = InferenceState(linfo, linfo.inferred::CodeInfo,
+                               true, true, InferenceParams())
         typeinf_loop(frame)
         ccall(:jl_typeinf_end, Void, ())
         @assert frame.inferred # TODO: deal with this better
@@ -2138,7 +2164,6 @@ function type_annotate!(sv::InferenceState)
     body = src.code::Array{Any,1}
     nexpr = length(body)
     i = 1
-    optimize = sv.optimize::Bool
     while i <= nexpr
         st_i = states[i]
         expr = body[i]
@@ -2151,7 +2176,7 @@ function type_annotate!(sv::InferenceState)
                 id = expr.args[1].id
                 record_slot_type!(id, widenconst(states[i+1][id].typ), src.slottypes)
             end
-        elseif optimize
+        elseif sv.optimize
             if ((isa(expr, Expr) && is_meta_expr(expr::Expr)) ||
                 isa(expr, LineNumberNode))
                 i += 1
@@ -2426,7 +2451,7 @@ function inlineable(f::ANY, ft::ANY, e::Expr, atypes::Vector{Any}, sv::Inference
     end
     topmod = _topmod(sv)
     # special-case inliners for known pure functions that compute types
-    if sv.inlining
+    if sv.params.inlining
         if isconstType(e.typ,true)
             if (is(f, apply_type) || is(f, fieldtype) || is(f, typeof) ||
                 istopfunction(topmod, f, :typejoin) ||
@@ -2460,7 +2485,7 @@ function inlineable(f::ANY, ft::ANY, e::Expr, atypes::Vector{Any}, sv::Inference
     function invoke_NF()
         # converts a :call to :invoke
         local nu = countunionsplit(atypes)
-        nu > MAX_UNION_SPLITTING && return NF
+        nu > sv.params.MAX_UNION_SPLITTING && return NF
 
         if nu > 1
             local spec_hit = nothing
@@ -2560,12 +2585,12 @@ function inlineable(f::ANY, ft::ANY, e::Expr, atypes::Vector{Any}, sv::Inference
         end
         return NF
     end
-    if !sv.inlining
+    if !sv.params.inlining
         return invoke_NF()
     end
 
-    if length(atype_unlimited.parameters) - 1 > MAX_TUPLETYPE_LEN
-        atype = limit_tuple_type(atype_unlimited)
+    if length(atype_unlimited.parameters) - 1 > sv.params.MAX_TUPLETYPE_LEN
+        atype = limit_tuple_type(atype_unlimited, sv.params)
     else
         atype = atype_unlimited
     end
@@ -2646,7 +2671,7 @@ function inlineable(f::ANY, ft::ANY, e::Expr, atypes::Vector{Any}, sv::Inference
                 linfo = code_for_method(method, metharg, methsp)
             end
             if isa(linfo, MethodInstance)
-                frame = typeinf_frame(linfo::MethodInstance, true, true, nothing)
+                frame = typeinf_frame(linfo::MethodInstance, nothing, true, true, sv.params)
             end
         end
         if isa(frame, InferenceState) && frame.inferred
@@ -3071,7 +3096,7 @@ function inlining_pass(e::Expr, sv::InferenceState)
         end
     end
 
-    if sv.inlining
+    if sv.params.inlining
         if isdefined(Main, :Base) &&
             ((isdefined(Main.Base, :^) && is(f, Main.Base.:^)) ||
              (isdefined(Main.Base, :.^) && is(f, Main.Base.:.^))) &&
@@ -3150,7 +3175,7 @@ function inlining_pass(e::Expr, sv::InferenceState)
                 elseif isa(aarg, Tuple)
                     newargs[i-2] = Any[ QuoteNode(x) for x in aarg ]
                 elseif isa(t, DataType) && t.name === Tuple.name && !isvatuple(t) &&
-                        effect_free(aarg, sv.src, sv.mod, true) && length(t.parameters) <= MAX_TUPLE_SPLAT
+                        effect_free(aarg, sv.src, sv.mod, true) && length(t.parameters) <= sv.params.MAX_TUPLE_SPLAT
                     # apply(f,t::(x,y)) => f(t[1],t[2])
                     tp = t.parameters
                     newargs[i-2] = Any[ mk_getfield(aarg,j,tp[j]) for j=1:length(tp) ]
@@ -3951,10 +3976,12 @@ function reindex_labels!(sv::InferenceState)
     end
 end
 
-function return_type(f::ANY, t::ANY)
+function return_type(f::ANY, t::ANY, params::InferenceParams=InferenceParams())
+    # NOTE: if not processed by pure_eval_call during inference, a call to return_type
+    #       might use difference InferenceParams than the method it is contained in...
     rt = Union{}
     for m in _methods(f, t, -1)
-        ty = typeinf_type(m[3], m[1], m[2])
+        ty = typeinf_type(m[3], m[1], m[2], true, params)
         ty === nothing && return Any
         rt = tmerge(rt, ty)
         rt === Any && break
@@ -3988,7 +4015,7 @@ let fs = Any[typeinf_ext, typeinf_loop, typeinf_edge, occurs_outside_getfield, e
                     typ[i] = typ[i].ub
                 end
             end
-            typeinf_type(m[3], Tuple{typ...}, m[2])
+            typeinf_type(m[3], Tuple{typ...}, m[2], true, InferenceParams())
         end
     end
 end