From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 26 Aug 2020 07:07:08 +0000 (-0700)
Subject: regex-emacs omit POS runtime check
X-Git-Tag: emacs-28.0.90~6398
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=438975bbaa25b7de74993e7928c45cf5779442b8;p=emacs.git

regex-emacs omit POS runtime check

* src/regex-emacs.c (re_match_2_internal): Replace unnecessary
runtime check of POS with some eassumes.
---

diff --git a/src/regex-emacs.c b/src/regex-emacs.c
index c44cce9f787..954a193371a 100644
--- a/src/regex-emacs.c
+++ b/src/regex-emacs.c
@@ -3864,6 +3864,10 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 		     re_char *string2, ptrdiff_t size2,
 		     ptrdiff_t pos, struct re_registers *regs, ptrdiff_t stop)
 {
+  eassume (0 <= size1);
+  eassume (0 <= size2);
+  eassume (0 <= pos && pos <= stop && stop <= size1 + size2);
+
   /* General temporaries.  */
   int mcnt;
 
@@ -3979,14 +3983,6 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
       best_regend = best_regstart + num_regs;
     }
 
-  /* The starting position is bogus.  */
-  if (pos < 0 || pos > size1 + size2)
-    {
-      unbind_to (count, Qnil);
-      SAFE_FREE ();
-      return -1;
-    }
-
   /* Initialize subexpression text positions to -1 to mark ones that no
      start_memory/stop_memory has been seen for.  */
   for (ptrdiff_t reg = 1; reg < num_regs; reg++)