Align interpreter and codegen error behavior of setglobal! and friends

Currently this is an ErrorException in the runtime/interpreter, but a TypeError
in codegen. This is not permitted - which error is thrown is
semantically observable and codegen is not permitted to change it.
Worse, inference is also inconsistent about whether this is TypeError or
ErrorException, so this could actually lead to type confusion and crashes.
Fix all that by having the runtime also emit a TypeError here. However,
in order to not lose the binding name in the error message, adjust
the TypeError context field to permit a binding.

Author: Keno

Compiler/src/abstractinterpretation.jl

@@ -2485,7 +2485,7 @@ function abstract_eval_setglobal!(interp::AbstractInterpreter, sv::AbsIntState,
             (rt, exct) = global_assignment_rt_exct(interp, sv, saw_latestworld, gr, v)
             return CallMeta(rt, exct, Effects(setglobal!_effects, nothrow=exct===Bottom), GlobalAccessInfo(convert(Core.Binding, gr)))
         end
-        return CallMeta(Union{}, TypeError, EFFECTS_THROWS, NoCallInfo())
+        return CallMeta(Union{}, Union{TypeError, ErrorException}, EFFECTS_THROWS, NoCallInfo())
     end
     ⊑ = partialorder(typeinf_lattice(interp))
     if !(hasintersect(widenconst(M), Module) && hasintersect(widenconst(s), Symbol))
@@ -3751,7 +3751,7 @@ end
 
 function global_assignment_rt_exct(interp::AbstractInterpreter, sv::AbsIntState, saw_latestworld::Bool, g::GlobalRef, @nospecialize(newty))
     if saw_latestworld
-        return Pair{Any,Any}(newty, ErrorException)
+        return Pair{Any,Any}(newty, Union{TypeError, ErrorException})
     end
     newty′ = RefValue{Any}(newty)
     (valid_worlds, ret) = scan_partitions(interp, g, sv.world) do interp::AbstractInterpreter, ::Core.Binding, partition::Core.BindingPartition
@@ -3766,15 +3766,16 @@ function global_assignment_binding_rt_exct(interp::AbstractInterpreter, partitio
     if is_some_guard(kind)
         return Pair{Any,Any}(newty, ErrorException)
     elseif is_some_const_binding(kind) || is_some_imported(kind)
-        return Pair{Any,Any}(Bottom, ErrorException)
+        # N.B.: Backdating should not improve inference in an earlier world
+        return Pair{Any,Any}(kind == PARTITION_KIND_BACKDATED_CONST ? newty : Bottom, ErrorException)
     end
     ty = kind == PARTITION_KIND_DECLARED ? Any : partition_restriction(partition)
     wnewty = widenconst(newty)
     if !hasintersect(wnewty, ty)
-        return Pair{Any,Any}(Bottom, ErrorException)
+        return Pair{Any,Any}(Bottom, TypeError)
     elseif !(wnewty <: ty)
         retty = tmeet(typeinf_lattice(interp), newty, ty)
-        return Pair{Any,Any}(retty, ErrorException)
+        return Pair{Any,Any}(retty, TypeError)
     end
     return Pair{Any,Any}(newty, Bottom)
 end

Compiler/test/inference.jl

@@ -6458,7 +6458,7 @@ end
 global invalid_setglobal!_exct_modeling::Int
 @test Base.infer_exception_type((Float64,)) do x
     setglobal!(@__MODULE__, :invalid_setglobal!_exct_modeling, x)
-end == ErrorException
+end == TypeError
 
 # Issue #58257 - Hang in inference during BindingPartition resolution
 module A58257

base/boot.jl

@@ -410,7 +410,7 @@ struct TypeError <: Exception
     # `context` optionally adds extra detail, e.g. the name of the type parameter
     # that got a bad value.
     func::Symbol
-    context::Union{AbstractString,Symbol}
+    context::Union{AbstractString,Binding,Symbol}
     expected::Type
     got
     TypeError(func, context, @nospecialize(expected::Type), @nospecialize(got)) =

base/errorshow.jl

@@ -91,6 +91,9 @@ function showerror(io::IO, ex::TypeError)
         end
         if ex.context == ""
             ctx = "in $(ex.func)"
+        elseif isa(ex.context, Core.Binding)
+            gr = ex.context.globalref
+            ctx = "in $(ex.func) of global binding `$(gr.mod).$(gr.name)`"
         elseif ex.func === :var"keyword argument"
             ctx = "in keyword argument $(ex.context)"
         else

src/codegen.cpp

@@ -3231,8 +3231,7 @@ static jl_cgval_t emit_globalop(jl_codectx_t &ctx, jl_module_t *mod, jl_sym_t *s
             if (ty != nullptr) {
                 const std::string fname = issetglobal ? "setglobal!" : isreplaceglobal ? "replaceglobal!" : isswapglobal ? "swapglobal!" : ismodifyglobal ? "modifyglobal!" : "setglobalonce!";
                 if (!ismodifyglobal) {
-                    // TODO: use typeassert in jl_check_binding_assign_value too
-                    emit_typecheck(ctx, rval, ty, "typeassert");
+                    emit_typecheck(ctx, rval, ty, fname.c_str());
                     rval = update_julia_type(ctx, rval, ty);
                     if (rval.typ == jl_bottom_type)
                         return jl_cgval_t();

src/datatype.c

@@ -1992,11 +1992,11 @@ jl_value_t *swap_nth_field(jl_datatype_t *st, jl_value_t *v, size_t i, jl_value_
     }
 }
 
-inline jl_value_t *modify_value(jl_value_t *ty, _Atomic(jl_value_t*) *p, jl_value_t *parent, jl_value_t *op, jl_value_t *rhs, int isatomic, jl_module_t *mod, jl_sym_t *name)
+inline jl_value_t *modify_value(jl_value_t *ty, _Atomic(jl_value_t*) *p, jl_value_t *parent, jl_value_t *op, jl_value_t *rhs, int isatomic, jl_binding_t *b, jl_module_t *mod, jl_sym_t *name)
 {
     jl_value_t *r = isatomic ? jl_atomic_load(p) : jl_atomic_load_relaxed(p);
     if (__unlikely(r == NULL)) {
-        if (mod && name)
+        if (b)
             jl_undefined_var_error(name, (jl_value_t*)mod);
         jl_throw(jl_undefref_exception);
     }
@@ -2007,11 +2007,10 @@ inline jl_value_t *modify_value(jl_value_t *ty, _Atomic(jl_value_t*) *p, jl_valu
         args[1] = rhs;
         jl_value_t *y = jl_apply_generic(op, args, 2);
         args[1] = y;
-        if (!jl_isa(y, ty)) {
-            if (mod && name)
-                jl_errorf("cannot assign an incompatible value to the global %s.%s.", jl_symbol_name(mod->name), jl_symbol_name(name));
+        if (b)
+            jl_check_binding_assign_value(b, mod, name, y, "modifyglobal!");
+        else if (!jl_isa(y, ty))
             jl_type_error(jl_is_genericmemory(parent) ? "memoryrefmodify!" : "modifyfield!", ty, y);
-        }
         if (isatomic ? jl_atomic_cmpswap(p, &r, y) : jl_atomic_cmpswap_release(p, &r, y)) {
             jl_gc_wb(parent, y);
             break;
@@ -2125,7 +2124,7 @@ jl_value_t *modify_nth_field(jl_datatype_t *st, jl_value_t *v, size_t i, jl_valu
     jl_value_t *ty = jl_field_type_concrete(st, i);
     char *p = (char*)v + offs;
     if (jl_field_isptr(st, i)) {
-        return modify_value(ty, (_Atomic(jl_value_t*)*)p, v, op, rhs, isatomic, NULL, NULL);
+        return modify_value(ty, (_Atomic(jl_value_t*)*)p, v, op, rhs, isatomic, NULL, NULL, NULL);
     }
     else {
         uint8_t *psel = jl_is_uniontype(ty) ? (uint8_t*)&p[jl_field_size(st, i) - 1] : NULL;

src/genericmemory.c

@@ -506,7 +506,7 @@ JL_DLLEXPORT jl_value_t *jl_memoryrefmodify(jl_genericmemoryref_t m, jl_value_t
     char *data = (char*)m.ptr_or_offset;
     if (layout->flags.arrayelem_isboxed) {
         assert(data - (char*)m.mem->ptr < sizeof(jl_value_t*) * m.mem->length);
-        return modify_value(eltype, (_Atomic(jl_value_t*)*)data, owner, op, rhs, isatomic, NULL, NULL);
+        return modify_value(eltype, (_Atomic(jl_value_t*)*)data, owner, op, rhs, isatomic, NULL, NULL, NULL);
     }
     size_t fsz = layout->size;
     uint8_t *psel = NULL;

src/julia.h

@@ -2086,6 +2086,10 @@ JL_DLLEXPORT void JL_NORETURN jl_type_error_rt(const char *fname,
                                                const char *context,
                                                jl_value_t *ty JL_MAYBE_UNROOTED,
                                                jl_value_t *got JL_MAYBE_UNROOTED);
+JL_DLLEXPORT void JL_NORETURN jl_type_error_global(const char *fname,
+                                               jl_binding_t *b JL_MAYBE_UNROOTED,
+                                               jl_value_t *ty JL_MAYBE_UNROOTED,
+                                               jl_value_t *got JL_MAYBE_UNROOTED);
 JL_DLLEXPORT void JL_NORETURN jl_undefined_var_error(jl_sym_t *var, jl_value_t *scope JL_MAYBE_UNROOTED);
 JL_DLLEXPORT void JL_NORETURN jl_has_no_field_error(jl_datatype_t *t, jl_sym_t *var);
 JL_DLLEXPORT void JL_NORETURN jl_argument_error(char *str);

src/julia_internal.h

@@ -882,7 +882,7 @@ int set_nth_fieldonce(jl_datatype_t *st, jl_value_t *v, size_t i, jl_value_t *rh
 jl_value_t *swap_bits(jl_value_t *ty, char *v, uint8_t *psel, jl_value_t *parent, jl_value_t *rhs, enum atomic_kind isatomic);
 jl_value_t *replace_value(jl_value_t *ty, _Atomic(jl_value_t*) *p, jl_value_t *parent, jl_value_t *expected, jl_value_t *rhs, int isatomic, jl_module_t *mod, jl_sym_t *name);
 jl_value_t *replace_bits(jl_value_t *ty, char *p, uint8_t *psel, jl_value_t *parent, jl_value_t *expected, jl_value_t *rhs, enum atomic_kind isatomic);
-jl_value_t *modify_value(jl_value_t *ty, _Atomic(jl_value_t*) *p, jl_value_t *parent, jl_value_t *op, jl_value_t *rhs, int isatomic, jl_module_t *mod, jl_sym_t *name);
+jl_value_t *modify_value(jl_value_t *ty, _Atomic(jl_value_t*) *p, jl_value_t *parent, jl_value_t *op, jl_value_t *rhs, int isatomic, jl_binding_t *b, jl_module_t *mod, jl_sym_t *name);
 jl_value_t *modify_bits(jl_value_t *ty, char *p, uint8_t *psel, jl_value_t *parent, jl_value_t *op, jl_value_t *rhs, enum atomic_kind isatomic);
 int setonce_bits(jl_datatype_t *rty, char *p, jl_value_t *owner, jl_value_t *rhs, enum atomic_kind isatomic);
 jl_expr_t *jl_exprn(jl_sym_t *head, size_t n);
@@ -895,6 +895,7 @@ jl_array_t *jl_get_loaded_modules(void);
 JL_DLLEXPORT int jl_datatype_isinlinealloc(jl_datatype_t *ty, int pointerfree);
 int jl_type_equality_is_identity(jl_value_t *t1, jl_value_t *t2) JL_NOTSAFEPOINT;
 
+jl_value_t *jl_check_binding_assign_value(jl_binding_t *b JL_PROPAGATES_ROOT, jl_module_t *mod, jl_sym_t *var, jl_value_t *rhs JL_MAYBE_UNROOTED, const char *msg);
 void jl_binding_set_type(jl_binding_t *b, jl_module_t *mod, jl_sym_t *sym, jl_value_t *ty);
 JL_DLLEXPORT void jl_declare_global(jl_module_t *m, jl_value_t *arg, jl_value_t *set_type, int strong);
 JL_DLLEXPORT jl_binding_partition_t *jl_declare_constant_val3(jl_binding_t *b JL_ROOTING_ARGUMENT, jl_module_t *mod, jl_sym_t *var, jl_value_t *val JL_ROOTED_ARGUMENT JL_MAYBE_UNROOTED, enum jl_partition_kind, size_t new_world) JL_GLOBALLY_ROOTED;

src/module.c

@@ -1886,34 +1886,32 @@ void jl_binding_deprecation_warning(jl_binding_t *b)
 
 // For a generally writable binding (checked using jl_check_binding_currently_writable in this world age), check whether
 // we can actually write the value `rhs` to it.
-jl_value_t *jl_check_binding_assign_value(jl_binding_t *b JL_PROPAGATES_ROOT, jl_module_t *mod, jl_sym_t *var, jl_value_t *rhs JL_MAYBE_UNROOTED)
+jl_value_t *jl_check_binding_assign_value(jl_binding_t *b JL_PROPAGATES_ROOT, jl_module_t *mod, jl_sym_t *var, jl_value_t *rhs JL_MAYBE_UNROOTED, const char *msg)
 {
     JL_GC_PUSH1(&rhs); // callee-rooted
     jl_binding_partition_t *bpart = jl_get_binding_partition(b, jl_current_task->world_age);
     enum jl_partition_kind kind = jl_binding_kind(bpart);
     assert(kind == PARTITION_KIND_DECLARED || kind == PARTITION_KIND_GLOBAL);
     jl_value_t *old_ty = kind == PARTITION_KIND_DECLARED ? (jl_value_t*)jl_any_type : bpart->restriction;
     JL_GC_PROMISE_ROOTED(old_ty);
-    if (old_ty != (jl_value_t*)jl_any_type && jl_typeof(rhs) != old_ty) {
-        if (!jl_isa(rhs, old_ty))
-            jl_errorf("cannot assign an incompatible value to the global %s.%s.",
-                        jl_symbol_name(mod->name), jl_symbol_name(var));
+    if (old_ty != (jl_value_t*)jl_any_type && jl_typeof(rhs) != old_ty && !jl_isa(rhs, old_ty)) {
+        jl_type_error_global(msg, b, old_ty, rhs);
     }
     JL_GC_POP();
     return old_ty;
 }
 
 JL_DLLEXPORT void jl_checked_assignment(jl_binding_t *b, jl_module_t *mod, jl_sym_t *var, jl_value_t *rhs)
 {
-    if (jl_check_binding_assign_value(b, mod, var, rhs) != NULL) {
+    if (jl_check_binding_assign_value(b, mod, var, rhs, "setglobal!") != NULL) {
         jl_atomic_store_release(&b->value, rhs);
         jl_gc_wb(b, rhs);
     }
 }
 
 JL_DLLEXPORT jl_value_t *jl_checked_swap(jl_binding_t *b, jl_module_t *mod, jl_sym_t *var, jl_value_t *rhs)
 {
-    jl_check_binding_assign_value(b, mod, var, rhs);
+    jl_check_binding_assign_value(b, mod, var, rhs, "swapglobal!");
     jl_value_t *old = jl_atomic_exchange(&b->value, rhs);
     jl_gc_wb(b, rhs);
     if (__unlikely(old == NULL))
@@ -1923,7 +1921,7 @@ JL_DLLEXPORT jl_value_t *jl_checked_swap(jl_binding_t *b, jl_module_t *mod, jl_s
 
 JL_DLLEXPORT jl_value_t *jl_checked_replace(jl_binding_t *b, jl_module_t *mod, jl_sym_t *var, jl_value_t *expected, jl_value_t *rhs)
 {
-    jl_value_t *ty = jl_check_binding_assign_value(b, mod, var, rhs);
+    jl_value_t *ty = jl_check_binding_assign_value(b, mod, var, rhs, "replaceglobal!");
     return replace_value(ty, &b->value, (jl_value_t*)b, expected, rhs, 1, mod, var);
 }
 
@@ -1937,12 +1935,12 @@ JL_DLLEXPORT jl_value_t *jl_checked_modify(jl_binding_t *b, jl_module_t *mod, jl
                   jl_symbol_name(mod->name), jl_symbol_name(var));
     jl_value_t *ty = bpart->restriction;
     JL_GC_PROMISE_ROOTED(ty);
-    return modify_value(ty, &b->value, (jl_value_t*)b, op, rhs, 1, mod, var);
+    return modify_value(ty, &b->value, (jl_value_t*)b, op, rhs, 1, b, mod, var);
 }
 
 JL_DLLEXPORT jl_value_t *jl_checked_assignonce(jl_binding_t *b, jl_module_t *mod, jl_sym_t *var, jl_value_t *rhs )
 {
-    jl_check_binding_assign_value(b, mod, var, rhs);
+    jl_check_binding_assign_value(b, mod, var, rhs, "setglobalonce!");
     jl_value_t *old = NULL;
     if (jl_atomic_cmpswap(&b->value, &old, rhs))
         jl_gc_wb(b, rhs);