commit cfcb952e30e01d7cce430829af8edc7afc94e0b1
author Lysandros Nikolaou <lisandrosnik@gmail.com> Sat Oct 31 21:06:03 2020 +0200
committer GitHub <noreply@github.com> Sat Oct 31 12:06:03 2020 -0700
tree 8a171bdafe7537ffc636aee5ee76afe9e5562a9b
parent dbaa07db671c4e5842629c8be912f2b0370be794

[3.9] bpo-42218: Correctly handle errors in left-recursive rules (GH-23065) (GH-23066)



Left-recursive rules need to check for errors explicitly, since
even if the rule returns NULL, the parsing might continue and lead
to long-distance failures.

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
(cherry picked from commit 02cdfc93f82fecdb7eae97a868d4ee222b9875d9)

Automerge-Triggered-By: GH:lysnikolaou

Parser/pegen/parse.c

diff --git a/Parser/pegen/parse.c b/Parser/pegen/parse.c
index bae9463..97cefa9 100644
--- a/Parser/pegen/parse.c
+++ b/Parser/pegen/parse.c
@@ -3460,6 +3460,8 @@
         }
         p->mark = _mark;
         void *_raw = dotted_name_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;
@@ -9044,6 +9046,8 @@
         }
         p->mark = _mark;
         void *_raw = bitwise_or_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;
@@ -9158,6 +9162,8 @@
         }
         p->mark = _mark;
         void *_raw = bitwise_xor_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;
@@ -9272,6 +9278,8 @@
         }
         p->mark = _mark;
         void *_raw = bitwise_and_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;
@@ -9386,6 +9394,8 @@
         }
         p->mark = _mark;
         void *_raw = shift_expr_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;
@@ -9539,6 +9549,8 @@
         }
         p->mark = _mark;
         void *_raw = sum_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;
@@ -9698,6 +9710,8 @@
         }
         p->mark = _mark;
         void *_raw = term_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;
@@ -10302,6 +10316,8 @@
         }
         p->mark = _mark;
         void *_raw = primary_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;
@@ -13962,6 +13978,8 @@
         }
         p->mark = _mark;
         void *_raw = t_primary_raw(p);
+        if (p->error_indicator)
+            return NULL;
         if (_raw == NULL || p->mark <= _resmark)
             break;
         _resmark = p->mark;