trim: Add Core.finalizer support

This adds the changes required to guess the MethodInstance that the
runtime will eventually invoke for this call, enqueue it for codegen,
and then verify its presence in the verifier.

Author: topolarity

Compiler/src/typeinfer.jl

@@ -1374,8 +1374,29 @@ function typeinf_type(interp::AbstractInterpreter, mi::MethodInstance)
     return ci.rettype
 end
 
+# Resolve a call, as described by `argtype` to a single matching
+# Method and return a compilable MethodInstance for the call, if
+# it will be runtime-dispatched to exactly that MethodInstance
+function compileable_specialization_for_call(interp::AbstractInterpreter, @nospecialize(argtype))
+    matches = findall(argtype, method_table(interp); limit = 1)
+    matches === nothing && return nothing
+    length(matches.matches) == 0 && return nothing
+    match = only(matches.matches)
+
+    compileable_atype = get_compileable_sig(match.method, match.spec_types, match.sparams)
+    compileable_atype === nothing && return nothing
+    if match.spec_types !== compileable_atype
+        sp_ = ccall(:jl_type_intersection_with_env, Any, (Any, Any), compileable_atype, method.sig)::SimpleVector
+        sparams = sp_[2]::SimpleVector
+        mi = specialize_method(match.method, compileable_atype, sparams)
+    else
+        mi = specialize_method(match.method, compileable_atype, match.sparams)
+    end
+    return mi
+end
+
 # collect a list of all code that is needed along with CodeInstance to codegen it fully
-function collectinvokes!(wq::Vector{CodeInstance}, ci::CodeInfo)
+function collectinvokes!(wq::Vector{CodeInstance}, ci::CodeInfo, sptypes::Vector{VarState})
     src = ci.code
     for i = 1:length(src)
         stmt = src[i]
@@ -1384,6 +1405,31 @@ function collectinvokes!(wq::Vector{CodeInstance}, ci::CodeInfo)
             edge = stmt.args[1]
             edge isa CodeInstance && isdefined(edge, :inferred) && push!(wq, edge)
         end
+
+        if isexpr(stmt, :call)
+            farg = stmt.args[1]
+            !applicable(argextype, farg, ci, sptypes) && continue # TODO: Why is this failing during bootstrap
+            ftyp = widenconst(argextype(farg, ci, sptypes))
+            if ftyp <: Builtin
+                # TODO: Make interp elsewhere
+                interp = NativeInterpreter(Base.get_world_counter())
+                if Core.finalizer isa ftyp && length(stmt.args) == 3
+                    finalizer = argextype(stmt.args[2], ci, sptypes)
+                    obj = argextype(stmt.args[3], ci, sptypes)
+                    atype = argtypes_to_type(Any[finalizer, obj])
+
+                    mi = compileable_specialization_for_call(interp, atype)
+                    mi === nothing && continue
+
+                    if mi.def.primary_world <= Base.get_world_counter() <= mi.def.deleted_world
+                        ci = typeinf_ext(interp, mi, SOURCE_MODE_GET_SOURCE)
+                        # TODO: separate workqueue for NativeInterpreter
+                        ci isa CodeInstance && push!(wq, ci)
+                    end
+                    # push!(wq, mi)
+                end
+            end
+        end
         # TODO: handle other StmtInfo like @cfunction and OpaqueClosure?
     end
 end
@@ -1420,8 +1466,9 @@ function add_codeinsts_to_jit!(interp::AbstractInterpreter, ci, source_mode::UIn
             end
         end
         push!(inspected, callee)
-        collectinvokes!(tocompile, src)
         mi = get_ci_mi(callee)
+        sptypes = sptypes_from_meth_instance(mi)
+        collectinvokes!(tocompile, src, sptypes)
         if iszero(ccall(:jl_mi_cache_has_ci, Cint, (Any, Any), mi, callee))
             cached = ccall(:jl_get_ci_equiv, Any, (Any, UInt), callee, get_inference_world(interp))::CodeInstance
             if cached === callee
@@ -1519,7 +1566,8 @@ function typeinf_ext_toplevel(methods::Vector{Any}, worlds::Vector{UInt}, trim_m
             end
             push!(inspected, callee)
             if src isa CodeInfo
-                collectinvokes!(tocompile, src)
+                sptypes = sptypes_from_meth_instance(mi)
+                collectinvokes!(tocompile, src, sptypes)
                 # try to reuse an existing CodeInstance from before to avoid making duplicates in the cache
                 if iszero(ccall(:jl_mi_cache_has_ci, Cint, (Any, Any), mi, callee))
                     cached = ccall(:jl_get_ci_equiv, Any, (Any, UInt), callee, this_world)::CodeInstance

Compiler/src/verifytrim.jl

@@ -199,6 +199,8 @@ function verify_codeinstance!(codeinst::CodeInstance, codeinfo::CodeInfo, inspec
                 if !may_dispatch(ftyp)
                     continue
                 end
+                # TODO: Make interp elsewhere
+                interp = NativeInterpreter(Base.get_world_counter())
                 if Core._apply_iterate isa ftyp
                     if length(stmt.args) >= 3
                         # args[1] is _apply_iterate object
@@ -219,9 +221,17 @@ function verify_codeinstance!(codeinst::CodeInstance, codeinfo::CodeInfo, inspec
                     end
                 elseif Core.finalizer isa ftyp
                     if length(stmt.args) == 3
-                        # TODO: check that calling `args[1](args[2])` is defined before warning
+                        finalizer = argextype(stmt.args[2], ci, sptypes)
+                        obj = argextype(stmt.args[3], ci, sptypes)
+                        atype = argtypes_to_type(Any[finalizer, obj])
+
+                        mi = compileable_specialization_for_call(interp, atype)
+                        if mi !== nothing
+                            ci = get(caches, mi, nothing)
+                            ci isa CodeInstance && continue
+                        end
+
                         error = "unresolved finalizer registered"
-                        warn = true
                     end
                 else
                     error = "unresolved call to builtin"

base/runtime_internals.jl

@@ -1622,12 +1622,18 @@ end
 
 is_nospecialized(method::Method) = method.nospecialize ≠ 0
 is_nospecializeinfer(method::Method) = method.nospecializeinfer && is_nospecialized(method)
+
+"""
+Return MethodInstance corresponding to `atype` and `sparams`.
+
+No widening / narrowing / compileable-normalization of `atype` is performed.
+"""
 function specialize_method(method::Method, @nospecialize(atype), sparams::SimpleVector; preexisting::Bool=false)
     @inline
     if isa(atype, UnionAll)
         atype, sparams = normalize_typevars(method, atype, sparams)
     end
-    if is_nospecializeinfer(method)
+    if is_nospecializeinfer(method) # TODO: this shouldn't be here
         atype = get_nospecializeinfer_sig(method, atype, sparams)
     end
     if preexisting

src/gf.c

@@ -3211,6 +3211,7 @@ JL_DLLEXPORT jl_method_instance_t *jl_method_match_to_mi(jl_method_match_t *matc
 }
 
 // compile-time method lookup
+// intersect types with the MT, and return a single compileable specialization that covers the intersection.
 jl_method_instance_t *jl_get_specialization1(jl_tupletype_t *types, size_t world, int mt_cache)
 {
     if (jl_has_free_typevars((jl_value_t*)types))