Fix isset on pseudoglobals

oulgen · fredemmott · commit 950b326f6dbe · 2018-05-11T08:52:42.000-07:00
Summary: Fixes #8187 Reviewed By: fredemmott Differential Revision: D7953851
diff --git a/hphp/hack/src/hhbc/emit_expression.ml b/hphp/hack/src/hhbc/emit_expression.ml
@@ -1169,14 +1169,21 @@ and emit_call_isset_expr env outer_pos (pos, expr_ as expr) =
     gather [
       emit_expr ~need_ref:false env e;
       emit_pos outer_pos;
-      instr (IIsset IssetG)
+      instr_issetg
     ]
   | A.Array_get (base_expr, opt_elem_expr) ->
     emit_array_get ~need_ref:false env pos None QueryOp.Isset base_expr opt_elem_expr
   | A.Class_get (cid, id)  ->
     emit_class_get env None QueryOp.Isset false cid id
   | A.Obj_get (expr, prop, nullflavor) ->
     emit_obj_get ~need_ref:false env pos None QueryOp.Isset expr prop nullflavor
+  | A.Lvar (_, n) when SN.Superglobals.is_superglobal n ->
+    gather [
+      emit_pos outer_pos;
+      instr_string @@ SU.Locals.strip_dollar n;
+      emit_pos outer_pos;
+      instr_issetg
+    ]
   | A.Lvar ((_, name) as id)
     when is_local_this env name && not (Emit_env.get_needs_local_this env) ->
     gather [
diff --git a/hphp/hack/src/hhbc/instruction_sequence.ml b/hphp/hack/src/hhbc/instruction_sequence.ml
@@ -118,6 +118,7 @@ let instr_setn = instr (IMutator SetN)
 let instr_unsetl local = instr (IMutator (UnsetL local))
 let instr_issetl local = instr (IIsset (IssetL local))
 let instr_issetn = instr (IIsset IssetN)
+let instr_issetg = instr (IIsset IssetG)
 let instr_issets = instr (IIsset (IssetS class_ref_rewrite_sentinel))
 let instr_emptys = instr (IIsset (EmptyS class_ref_rewrite_sentinel))
 let instr_emptyn = instr (IIsset EmptyN)
diff --git a/hphp/test/slow/global_vars/isset_unset_superglobals.php b/hphp/test/slow/global_vars/isset_unset_superglobals.php
@@ -0,0 +1,10 @@
+<?hh
+
+var_dump(isset($_GET));
+var_dump(isset($GLOBALS));
+
+$_GET = 1;
+$_GET;
+
+unset($_GET);
+unset($GLOBALS);
diff --git a/hphp/test/slow/global_vars/isset_unset_superglobals.php.expect b/hphp/test/slow/global_vars/isset_unset_superglobals.php.expect
@@ -0,0 +1,2 @@
+bool(true)
+bool(true)
