Consolidate various isdefined functionality into a new builtin

Compiler/src/Compiler.jl

@@ -49,7 +49,7 @@ using Core: ABIOverride, Builtin, CodeInstance, IntrinsicFunction, MethodInstanc
 
 using Base
 using Base: @_foldable_meta, @_gc_preserve_begin, @_gc_preserve_end, @nospecializeinfer,
-    BINDING_KIND_GLOBAL, Base, BitVector, Bottom, Callable, DataTypeFieldDesc,
+    BINDING_KIND_GLOBAL, BINDING_KIND_UNDEF_CONST, Base, BitVector, Bottom, Callable, DataTypeFieldDesc,
     EffectsOverride, Filter, Generator, IteratorSize, JLOptions, NUM_EFFECTS_OVERRIDES,
     OneTo, Ordering, RefValue, SizeUnknown, _NAMEDTUPLE_NAME,
     _array_for, _bits_findnext, _methods_by_ftype, _uniontypes, all, allocatedinline, any,
@@ -58,7 +58,7 @@ using Base: @_foldable_meta, @_gc_preserve_begin, @_gc_preserve_end, @nospeciali
     datatype_pointerfree, decode_effects_override, diff_names, fieldindex,
     generating_output, get_nospecializeinfer_sig, get_world_counter, has_free_typevars,
     hasgenerator, hasintersect, indexed_iterate, isType, is_file_tracked, is_function_def,
-    is_meta_expr, is_meta_expr_head, is_nospecialized, is_nospecializeinfer,
+    is_meta_expr, is_meta_expr_head, is_nospecialized, is_nospecializeinfer, is_defined_const_binding,
     is_some_const_binding, is_some_guard, is_some_imported, is_valid_intrinsic_elptr,
     isbitsunion, isconcretedispatch, isdispatchelem, isexpr, isfieldatomic, isidentityfree,
     iskindtype, ismutabletypename, ismutationfree, issingletontype, isvarargtype, isvatuple,

Compiler/src/abstractinterpretation.jl

@@ -2637,21 +2637,14 @@ function abstract_call_known(interp::AbstractInterpreter, @nospecialize(f),
         elseif f === Core.getfield && argtypes_are_actually_getglobal(argtypes)
             return Future(abstract_eval_getglobal(interp, sv, si.saw_latestworld, argtypes))
         elseif f === Core.isdefined && argtypes_are_actually_getglobal(argtypes)
-            exct = Bottom
-            if length(argtypes) == 4
-                order = argtypes[4]
-                exct = global_order_exct(order, #=loading=#true, #=storing=#false)
-                if !(isa(order, Const) && get_atomic_order(order.val, #=loading=#true, #=storing=#false).x >= MEMORY_ORDER_UNORDERED.x)
-                    exct = Union{exct, ConcurrencyViolationError}
-                end
-            end
-            return Future(merge_exct(CallMeta(abstract_eval_isdefined(
-                    interp,
-                    GlobalRef((argtypes[2]::Const).val::Module,
-                              (argtypes[3]::Const).val::Symbol),
-                    si.saw_latestworld,
-                    sv),
-                NoCallInfo()), exct))
+            return Future(abstract_eval_isdefinedglobal(interp, argtypes[2], argtypes[3], Const(true),
+                length(argtypes) == 4 ? argtypes[4] : Const(:unordered),
+                si.saw_latestworld, sv))
+        elseif f === Core.isdefinedglobal && 3 <= length(argtypes) <= 5
+            return Future(abstract_eval_isdefinedglobal(interp, argtypes[2], argtypes[3],
+                length(argtypes) >= 4 ? argtypes[4] : Const(true),
+                length(argtypes) >= 5 ? argtypes[5] : Const(:unordered),
+                si.saw_latestworld, sv))
         elseif f === Core.get_binding_type
             return Future(abstract_eval_get_binding_type(interp, sv, argtypes))
         end
@@ -3203,21 +3196,73 @@ function abstract_eval_isdefined_expr(interp::AbstractInterpreter, e::Expr, ssta
     return abstract_eval_isdefined(interp, sym, sstate.saw_latestworld, sv)
 end
 
-function abstract_eval_isdefined(interp::AbstractInterpreter, @nospecialize(sym), saw_latestworld::Bool, sv::AbsIntState)
+const generic_isdefinedglobal_effects = Effects(EFFECTS_TOTAL, consistent=ALWAYS_FALSE, nothrow=false)
+function abstract_eval_isdefinedglobal(interp::AbstractInterpreter, mod::Module, sym::Symbol, allow_import::Union{Bool, Nothing}, saw_latestworld::Bool, sv::AbsIntState)
     rt = Bool
+    if saw_latestworld
+        return RTEffects(rt, Union{}, Effects(generic_isdefinedglobal_effects, nothrow=true))
+    end
+
     effects = EFFECTS_TOTAL
-    exct = Union{}
-    isa(sym, Symbol) && (sym = GlobalRef(frame_module(sv), sym))
-    if isa(sym, GlobalRef)
-        rte = abstract_eval_globalref(interp, sym, saw_latestworld, sv)
+    partition = lookup_binding_partition!(interp, GlobalRef(mod, sym), sv)
+    if allow_import !== true && is_some_imported(binding_kind(partition))
+        if allow_import === false
+            rt = Const(false)
+        else
+            effects = Effects(generic_isdefinedglobal_effects, nothrow=true)
+        end
+    else
+        partition = walk_binding_partition!(interp, partition, sv)
+        rte = abstract_eval_partition_load(interp, partition)
         if rte.exct == Union{}
             rt = Const(true)
         elseif rte.rt === Union{} && rte.exct === UndefVarError
             rt = Const(false)
         else
-            effects = Effects(EFFECTS_TOTAL; consistent=ALWAYS_FALSE)
+            effects = Effects(generic_isdefinedglobal_effects, nothrow=true)
+        end
+    end
+    return RTEffects(rt, Union{}, effects)
+end
+
+function abstract_eval_isdefinedglobal(interp::AbstractInterpreter, @nospecialize(M), @nospecialize(s), @nospecialize(allow_import_arg), @nospecialize(order_arg), saw_latestworld::Bool, sv::AbsIntState)
+    exct = Bottom
+    allow_import = true
+    if allow_import_arg !== nothing
+        if !isa(allow_import_arg, Const)
+            allow_import = nothing
+            if widenconst(allow_import_arg) != Bool
+                exct = Union{exct, TypeError}
+            end
+        else
+            allow_import = allow_import_arg.val
+        end
+    end
+    if order_arg !== nothing
+        exct = global_order_exct(order_arg, #=loading=#true, #=storing=#false)
+        if !(isa(order_arg, Const) && get_atomic_order(order_arg.val, #=loading=#true, #=storing=#false).x >= MEMORY_ORDER_UNORDERED.x)
+            exct = Union{exct, ConcurrencyViolationError}
+        end
+    end
+    if M isa Const && s isa Const
+        M, s = M.val, s.val
+        if M isa Module && s isa Symbol
+            return merge_exct(CallMeta(abstract_eval_isdefinedglobal(interp, M, s, allow_import, saw_latestworld, sv), NoCallInfo()), exct)
         end
-    elseif isexpr(sym, :static_parameter)
+        return CallMeta(Union{}, TypeError, EFFECTS_THROWS, NoCallInfo())
+    elseif !hasintersect(widenconst(M), Module) || !hasintersect(widenconst(s), Symbol)
+        return CallMeta(Union{}, TypeError, EFFECTS_THROWS, NoCallInfo())
+    elseif M ⊑ Module && s ⊑ Symbol
+        return CallMeta(Bool, Union{exct, UndefVarError}, generic_isdefinedglobal_effects, NoCallInfo())
+    end
+    return CallMeta(Bool, Union{exct, TypeError, UndefVarError}, generic_isdefinedglobal_effects, NoCallInfo())
+end
+
+function abstract_eval_isdefined(interp::AbstractInterpreter, @nospecialize(sym), saw_latestworld::Bool, sv::AbsIntState)
+    rt = Bool
+    effects = EFFECTS_TOTAL
+    exct = Union{}
+    if isexpr(sym, :static_parameter)
         n = sym.args[1]::Int
         if 1 <= n <= length(sv.sptypes)
             sp = sv.sptypes[n]
@@ -3443,22 +3488,31 @@ function abstract_eval_globalref_type(g::GlobalRef, src::Union{CodeInfo, IRCode,
     return partition_restriction(partition)
 end
 
-function abstract_eval_binding_partition!(interp::AbstractInterpreter, g::GlobalRef, sv::AbsIntState)
+function lookup_binding_partition!(interp::AbstractInterpreter, g::GlobalRef, sv::AbsIntState)
     force_binding_resolution!(g)
     partition = lookup_binding_partition(get_inference_world(interp), g)
     update_valid_age!(sv, WorldRange(partition.min_world, partition.max_world))
+    partition
+end
 
+function walk_binding_partition!(interp::AbstractInterpreter, partition::Core.BindingPartition, sv::AbsIntState)
     while is_some_imported(binding_kind(partition))
         imported_binding = partition_restriction(partition)::Core.Binding
         partition = lookup_binding_partition(get_inference_world(interp), imported_binding)
         update_valid_age!(sv, WorldRange(partition.min_world, partition.max_world))
     end
+    return partition
+end
 
+function abstract_eval_binding_partition!(interp::AbstractInterpreter, g::GlobalRef, sv::AbsIntState)
+    partition = lookup_binding_partition!(interp, g, sv)
+    partition = walk_binding_partition!(interp, partition, sv)
     return partition
 end
 
 function abstract_eval_partition_load(interp::AbstractInterpreter, partition::Core.BindingPartition)
-    if is_some_guard(binding_kind(partition))
+    kind = binding_kind(partition)
+    if is_some_guard(kind) || kind == BINDING_KIND_UNDEF_CONST
         if InferenceParams(interp).assume_bindings_static
             return RTEffects(Union{}, UndefVarError, EFFECTS_THROWS)
         else
@@ -3468,13 +3522,12 @@ function abstract_eval_partition_load(interp::AbstractInterpreter, partition::Co
         end
     end
 
-    if is_some_const_binding(binding_kind(partition))
+    if is_defined_const_binding(kind)
         rt = Const(partition_restriction(partition))
         return RTEffects(rt, Union{}, Effects(EFFECTS_TOTAL, inaccessiblememonly=is_mutation_free_argtype(rt) ? ALWAYS_TRUE : ALWAYS_FALSE))
     end
 
     rt = partition_restriction(partition)
-
     return RTEffects(rt, UndefVarError, generic_getglobal_effects)
 end
 

Compiler/src/ssair/verify.jl

@@ -366,7 +366,7 @@ function verify_ir(ir::IRCode, print::Bool=true,
                     @verify_error "Assignment should have been removed during SSA conversion"
                     raise_error()
                 elseif stmt.head === :isdefined
-                    if length(stmt.args) > 2 || (length(stmt.args) == 2 && !isa(stmt.args[2], Bool))
+                    if length(stmt.args) > 2
                         @verify_error "malformed isdefined"
                         raise_error()
                     end
@@ -382,7 +382,7 @@ function verify_ir(ir::IRCode, print::Bool=true,
                 elseif stmt.head === :foreigncall
                     isforeigncall = true
                 elseif stmt.head === :isdefined && length(stmt.args) == 1 &&
-                        (stmt.args[1] isa GlobalRef || isexpr(stmt.args[1], :static_parameter))
+                        isexpr(stmt.args[1], :static_parameter)
                     # a GlobalRef or static_parameter isdefined check does not evaluate its argument
                     continue
                 elseif stmt.head === :call

base/boot.jl

@@ -231,7 +231,7 @@ export
     fieldtype, getfield, setfield!, swapfield!, modifyfield!, replacefield!, setfieldonce!,
     nfields, throw, tuple, ===, isdefined, eval,
     # access to globals
-    getglobal, setglobal!, swapglobal!, modifyglobal!, replaceglobal!, setglobalonce!,
+    getglobal, setglobal!, swapglobal!, modifyglobal!, replaceglobal!, setglobalonce!, isdefinedglobal,
     # ifelse, sizeof    # not exported, to avoid conflicting with Base
     # type reflection
     <:, typeof, isa, typeassert,

base/docs/basedocs.jl

@@ -2754,6 +2754,9 @@ compatible with the stores to that location. Otherwise, if not declared as
 
 To test whether an array element is defined, use [`isassigned`](@ref) instead.
 
+The global variable variant is supported for compatibility with older julia
+releases. For new code, prefer [`isdefinedglobal`](@ref).
+
 See also [`@isdefined`](@ref).
 
 # Examples
@@ -2781,6 +2784,37 @@ false
 """
 isdefined
 
+
+"""
+    isdefinedglobal(m::Module, s::Symbol, [allow_import::Bool=true, [order::Symbol=:unordered]])
+
+Tests whether a global variable `s` is defined in module `m` (in the current world age).
+A variable is considered defined if and only if a value may be read from this global variable
+and an access will not throw. This includes both constants and global variables that have
+a value set.
+
+If `allow_import` is `false`, the global variable must be defined inside `m`
+and may not be imported from another module.
+
+See also [`@isdefined`](@ref).
+
+# Examples
+```jldoctest
+julia> isdefinedglobal(Base, :sum)
+true
+
+julia> isdefinedglobal(Base, :NonExistentMethod)
+false
+
+julia> isdefinedglobal(Base, :sum, false)
+true
+
+julia> isdefinedglobal(Main, :sum, false)
+false
+```
+"""
+isdefinedglobal
+
 """
     Memory{T}(undef, n)
 

doc/src/base/base.md

@@ -166,6 +166,7 @@ Core.replacefield!
 Core.swapfield!
 Core.setfieldonce!
 Core.isdefined
+Core.isdefinedglobal
 Base.@isdefined
 Base.convert
 Base.promote

doc/src/devdocs/ast.md

@@ -426,11 +426,8 @@ These symbols appear in the `head` field of [`Expr`](@ref)s in lowered form.
 
   * `isdefined`
 
-    `Expr(:isdefined, :x [, allow_import])` returns a Bool indicating whether `x` has
-    already been defined in the current scope. The optional second argument is a boolean
-    that specifies whether `x` should be considered defined by an import or if only constants
-    or globals in the current module count as being defined. If `x` is not a global, the argument
-    is ignored.
+    `Expr(:isdefined, :x)` returns a Bool indicating whether `x` has
+    already been defined in the current scope.
 
   * `the_exception`
 

src/builtin_proto.h

@@ -45,6 +45,7 @@ DECLARE_BUILTIN(invoke);
 DECLARE_BUILTIN(is);
 DECLARE_BUILTIN(isa);
 DECLARE_BUILTIN(isdefined);
+DECLARE_BUILTIN(isdefinedglobal);
 DECLARE_BUILTIN(issubtype);
 DECLARE_BUILTIN(memorynew);
 DECLARE_BUILTIN(memoryref);

src/builtins.c

@@ -1352,6 +1352,33 @@ JL_CALLABLE(jl_f_getglobal)
     return v;
 }
 
+JL_CALLABLE(jl_f_isdefinedglobal)
+{
+    jl_module_t *m = NULL;
+    jl_sym_t *s = NULL;
+    JL_NARGS(isdefined, 2, 3);
+    int allow_import = 1;
+    enum jl_memory_order order = jl_memory_order_unspecified;
+    JL_TYPECHK(isdefined, module, args[0]);
+    JL_TYPECHK(isdefined, symbol, args[1]);
+    if (nargs == 3) {
+        JL_TYPECHK(isdefined, bool, args[2]);
+        allow_import = jl_unbox_bool(args[2]);
+    }
+    if (nargs == 4) {
+        JL_TYPECHK(isdefined, symbol, args[3]);
+        order = jl_get_atomic_order_checked((jl_sym_t*)args[2], 1, 0);
+    }
+    m = (jl_module_t*)args[0];
+    s = (jl_sym_t*)args[1];
+    if (order == jl_memory_order_unspecified)
+        order = jl_memory_order_unordered;
+    if (order < jl_memory_order_unordered)
+        jl_atomic_error("isdefined: module binding cannot be accessed non-atomically");
+    int bound = jl_boundp(m, s, allow_import); // seq_cst always
+    return bound ? jl_true : jl_false;
+}
+
 JL_CALLABLE(jl_f_setglobal)
 {
     enum jl_memory_order order = jl_memory_order_release;
@@ -2451,6 +2478,7 @@ void jl_init_primitives(void) JL_GC_DISABLED
     // module bindings
     jl_builtin_getglobal = add_builtin_func("getglobal", jl_f_getglobal);
     jl_builtin_setglobal = add_builtin_func("setglobal!", jl_f_setglobal);
+    jl_builtin_isdefinedglobal = add_builtin_func("isdefinedglobal", jl_f_isdefinedglobal);
     add_builtin_func("get_binding_type", jl_f_get_binding_type);
     jl_builtin_swapglobal = add_builtin_func("swapglobal!", jl_f_swapglobal);
     jl_builtin_replaceglobal = add_builtin_func("replaceglobal!", jl_f_replaceglobal);