Address review comments

src/ast.c

@@ -153,25 +153,56 @@ static jl_value_t *scm_to_julia(fl_context_t *fl_ctx, value_t e, jl_module_t *mo
 static value_t julia_to_scm(fl_context_t *fl_ctx, jl_value_t *v);
 static jl_value_t *jl_expand_macros(jl_value_t *expr, jl_module_t *inmodule, struct macroctx_stack *macroctx, int onelevel, size_t world, int throw_load_error);
 
+static jl_sym_t *scmsym_to_julia(fl_context_t *fl_ctx, value_t s)
+{
+    assert(issymbol(s));
+    if (fl_isgensym(fl_ctx, s)) {
+        char gsname[16];
+        char *n = uint2str(&gsname[1], sizeof(gsname)-1,
+                           ((gensym_t*)ptr(s))->id, 10);
+        *(--n) = '#';
+        return jl_symbol(n);
+    }
+    return jl_symbol(symbol_name(fl_ctx, s));
+}
+
 static value_t fl_defined_julia_global(fl_context_t *fl_ctx, value_t *args, uint32_t nargs)
 {
     // tells whether a var is defined in and *by* the current module
     argcount(fl_ctx, "defined-julia-global", nargs, 1);
     (void)tosymbol(fl_ctx, args[0], "defined-julia-global");
     jl_ast_context_t *ctx = jl_ast_ctx(fl_ctx);
-    jl_sym_t *var = jl_symbol(symbol_name(fl_ctx, args[0]));
+    jl_sym_t *var = scmsym_to_julia(fl_ctx, args[0]);
     jl_binding_t *b = jl_get_module_binding(ctx->module, var, 0);
     return (b != NULL && jl_atomic_load_relaxed(&b->owner) == b) ? fl_ctx->T : fl_ctx->F;
 }
 
 static value_t fl_nothrow_julia_global(fl_context_t *fl_ctx, value_t *args, uint32_t nargs)
 {
     // tells whether a var is defined, in the sense that accessing it is nothrow
-    argcount(fl_ctx, "nothrow-julia-global", nargs, 1);
-    (void)tosymbol(fl_ctx, args[0], "nothrow-julia-global");
+    // can take either a symbol or a module and a symbol
     jl_ast_context_t *ctx = jl_ast_ctx(fl_ctx);
-    jl_sym_t *var = jl_symbol(symbol_name(fl_ctx, args[0]));
-    jl_binding_t *b = jl_get_module_binding(ctx->module, var, 0);
+    jl_module_t *mod = ctx->module;
+    jl_sym_t *var = NULL;
+    if (nargs == 1) {
+        (void)tosymbol(fl_ctx, args[0], "nothrow-julia-global");
+        var = scmsym_to_julia(fl_ctx, args[0]);
+    }
+    else {
+        argcount(fl_ctx, "nothrow-julia-global", nargs, 2);
+        value_t argmod = args[0];
+        if (iscvalue(argmod) && cv_class((cvalue_t*)ptr(argmod)) == jl_ast_ctx(fl_ctx)->jvtype) {
+            mod = *(jl_module_t**)cv_data((cvalue_t*)ptr(argmod));
+        } else {
+            (void)tosymbol(fl_ctx, argmod, "nothrow-julia-global");
+            if (scmsym_to_julia(fl_ctx, argmod) != jl_thismodule_sym) {
+                lerrorf(fl_ctx, fl_ctx->ArgError, "nothrow-julia-global: Unknown globalref module kind");
+            }
+        }
+        (void)tosymbol(fl_ctx, args[1], "nothrow-julia-global");
+        var = scmsym_to_julia(fl_ctx, args[1]);
+    }
+    jl_binding_t *b = jl_get_module_binding(mod, var, 0);
     b = b ? jl_atomic_load_relaxed(&b->owner) : NULL;
     return b != NULL && jl_atomic_load_relaxed(&b->value) != NULL ? fl_ctx->T : fl_ctx->F;
 }
@@ -434,20 +465,6 @@ JL_DLLEXPORT void fl_profile(const char *fname)
     jl_ast_ctx_leave(ctx);
 }
 
-
-static jl_sym_t *scmsym_to_julia(fl_context_t *fl_ctx, value_t s)
-{
-    assert(issymbol(s));
-    if (fl_isgensym(fl_ctx, s)) {
-        char gsname[16];
-        char *n = uint2str(&gsname[1], sizeof(gsname)-1,
-                           ((gensym_t*)ptr(s))->id, 10);
-        *(--n) = '#';
-        return jl_symbol(n);
-    }
-    return jl_symbol(symbol_name(fl_ctx, s));
-}
-
 static jl_value_t *scm_to_julia(fl_context_t *fl_ctx, value_t e, jl_module_t *mod)
 {
     jl_value_t *v = NULL;

src/julia-syntax.scm

@@ -4257,6 +4257,7 @@ f(x) = yt(x)
 (define (valid-ir-argument? e)
   (or (simple-atom? e)
       (and (outerref? e) (nothrow-julia-global (cadr e)))
+      (and (globalref? e) (nothrow-julia-global (cadr e) (caddr e)))
       (and (pair? e)
            (memq (car e) '(quote inert top core
                                  slot static_parameter)))))
@@ -4265,7 +4266,7 @@ f(x) = yt(x)
   (or (ssavalue? lhs)
       (valid-ir-argument? e)
       (and (symbol? lhs) (pair? e)
-           (memq (car e) '(new splatnew the_exception isdefined call invoke foreigncall cfunction gc_preserve_begin copyast new_opaque_closure)))))
+           (memq (car e) '(new splatnew the_exception isdefined call invoke foreigncall cfunction gc_preserve_begin copyast new_opaque_closure globalref outerref)))))
 
 (define (valid-ir-return? e)
   ;; returning lambda directly is needed for @generated
@@ -4422,6 +4423,13 @@ f(x) = yt(x)
            (or (memq aval (lam:args lam))
                (let ((vi (get vinfo-table aval #f)))
                  (and vi (vinfo:sa vi))))))
+    ;; TODO: We could also allow const globals here
+    (define (const-read-arg? x)
+      ;; Even if we have side effects, we know that singly-assigned
+      ;; locals cannot be affected them, so we can inline them anyway.
+      (or (simple-atom? x) (single-assign-var? x)
+        (and (pair? x)
+          (memq (car x) '(quote inert top core)))))
     ;; evaluate the arguments of a call, creating temporary locations as needed
     (define (compile-args lst break-labels)
       (if (null? lst) '()
@@ -4442,9 +4450,7 @@ f(x) = yt(x)
                                  '(null))))
                   (loop (cdr lst)
                         (cons (if (and
-                                   ;; Even if we have side effects, we know that singly-assigned
-                                   ;; locals cannot be affected them, so we can inline them anyway.
-                                   (or simple? (single-assign-var? aval))
+                                   (or simple? (const-read-arg? aval))
                                    (valid-body-ir-argument? aval))
                                   aval
                                   (let ((tmp (make-ssavalue)))

test/compiler/inference.jl

@@ -5491,6 +5491,11 @@ end
 @test Base.return_types(phic_type10) |> only === Int
 @test phic_type10() === 2
 
+undef_trycatch() = try (a_undef_trycatch = a_undef_trycatch, b = 2); return 1 catch end
+# `global a_undef_trycatch` could be defined dynamically, so both paths must be allowed
+@test Base.return_types(undef_trycatch) |> only === Union{Nothing, Int}
+@test undef_trycatch() === nothing
+
 # Test that `exit` returns `Union{}` (issue #51856)
 function test_exit_bottom(s)
     n = tryparse(Int, s)

test/core.jl

@@ -8048,3 +8048,15 @@ end
 let lin = Core.LineInfoNode(Base, first(methods(convert)), :foo, Int32(5), Int32(0))
     @test convert(LineNumberNode, lin) == LineNumberNode(5, :foo)
 end
+
+# Test that a nothrow-globalref doesn't get outlined during lowering
+module WellKnownGlobal
+    global well_known = 1
+end
+macro insert_global()
+    Expr(:call, GlobalRef(Base, :println), GlobalRef(WellKnownGlobal, :well_known))
+end
+check_globalref_lowering() = @insert_global
+let src = code_lowered(check_globalref_lowering)[1]
+    @test length(src.code) == 2
+end