xref: /third_party/glib/patch/backport-gregex-if-JIT-stack-limit-is-reached-fall-back-to-interpretive-matching.patch

From 406f85a48f1ec41cda15ae617a979f7df749cb27 Mon Sep 17 00:00:00 2001
From: Aleksei Rybalkin <aleksei@rybalkin.org>
Date: Sun, 20 Aug 2023 16:33:53 +0200
Subject: [PATCH 1/2] gregex: if JIT stack limit is reached, fall back to
 interpretive matching
 
Conflict:Move large_test_string to fix declaration-after-statement
Reference:https://gitlab.gnome.org/GNOME/glib/-/commit/406f85a48f1ec41cda15ae617a979f7df749cb27
 
---
 glib/gregex.c      | 13 ++++++++++---
 glib/tests/regex.c | 10 +++++++++-
 2 files changed, 19 insertions(+), 4 deletions(-)
 
diff --git a/glib/gregex.c b/glib/gregex.c
index 5ce034db41..1b3ee02f30 100644
--- a/glib/gregex.c
+++ b/glib/gregex.c
@@ -484,8 +484,6 @@ translate_match_error (gint errcode)
       /* not used by pcre2_match() */
       break;
     case PCRE2_ERROR_MATCHLIMIT:
-    case PCRE2_ERROR_JIT_STACKLIMIT:
-      return _("backtracking limit reached");
     case PCRE2_ERROR_CALLOUT:
       /* callouts are not implemented */
       break;
@@ -1107,8 +1105,17 @@ g_match_info_next (GMatchInfo  *match_info,
                                              opts,
                                              match_info->match_data,
                                              match_info->match_context);
+      /* if the JIT stack limit was reached, fall back to non-JIT matching in
+       * the next conditional statement */
+      if (match_info->matches == PCRE2_ERROR_JIT_STACKLIMIT)
+        {
+          g_info ("PCRE2 JIT stack limit reached, falling back to "
+                  "non-optimized matching.");
+          opts |= PCRE2_NO_JIT;
+          jit_status = JIT_STATUS_DISABLED;
+        }
     }
-  else
+  if (jit_status != JIT_STATUS_ENABLED)
     {
       match_info->matches = pcre2_match (match_info->regex->pcre_re,
                                          (PCRE2_SPTR8) match_info->string,
diff --git a/glib/tests/regex.c b/glib/tests/regex.c
index 821fc59608..f18db483c2 100644
--- a/glib/tests/regex.c
+++ b/glib/tests/regex.c
@@ -51,8 +51,9 @@
 /* A random value use to mark untouched integer variables. */
 #define UNTOUCHED -559038737
 
-/* A length of the test string in JIT stack test */
+/* Lengths of test strings in JIT stack tests */
 #define TEST_STRING_LEN 20000
+#define LARGE_TEST_STRING_LEN 200000
 
 static gint total;
 
@@ -2485,6 +2486,7 @@ int
 main (int argc, char *argv[])
 {
   char test_string[TEST_STRING_LEN];
+  char large_test_string[LARGE_TEST_STRING_LEN];
   setlocale (LC_ALL, "");
 
   g_test_init (&argc, &argv, NULL);
@@ -2711,6 +2713,12 @@ G_GNUC_END_IGNORE_DEPRECATIONS
   test_string[TEST_STRING_LEN - 1] = '\0';
   TEST_MATCH_SIMPLE ("^(?:[ \t\n]|[^[:cntrl:]])*$", test_string, 0, 0, TRUE);
 
+  /* Test that gregex falls back to unoptimized matching when reaching the JIT
+   * compiler stack limit */
+  memset (large_test_string, '*', LARGE_TEST_STRING_LEN);
+  large_test_string[LARGE_TEST_STRING_LEN - 1] = '\0';
+  TEST_MATCH_SIMPLE ("^(?:[ \t\n]|[^[:cntrl:]])*$", large_test_string, 0, 0, TRUE);
+
   /* TEST_MATCH(pattern, compile_opts, match_opts, string,
    * 		string_len, start_position, match_opts2, expected) */
   TEST_MATCH("a", 0, 0, "a", -1, 0, 0, TRUE);
-- 
GitLab
 
 
From 986fa3fdad5155924b17dbde16811d017a6413da Mon Sep 17 00:00:00 2001
From: Philip Withnall <philip@tecnocode.co.uk>
Date: Mon, 21 Aug 2023 10:19:43 +0000
Subject: [PATCH 2/2] Apply 2 suggestion(s) to 1 file(s)
 
Conflict:NA
Reference:https://gitlab.gnome.org/GNOME/glib/-/commit/986fa3fdad5155924b17dbde16811d017a6413da
 
---
 glib/gregex.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
 
diff --git a/glib/gregex.c b/glib/gregex.c
index 1b3ee02f30..b37a5e04c7 100644
--- a/glib/gregex.c
+++ b/glib/gregex.c
@@ -1109,12 +1109,13 @@ g_match_info_next (GMatchInfo  *match_info,
        * the next conditional statement */
       if (match_info->matches == PCRE2_ERROR_JIT_STACKLIMIT)
         {
-          g_info ("PCRE2 JIT stack limit reached, falling back to "
-                  "non-optimized matching.");
+          g_debug ("PCRE2 JIT stack limit reached, falling back to "
+                   "non-optimized matching.");
           opts |= PCRE2_NO_JIT;
           jit_status = JIT_STATUS_DISABLED;
         }
     }
+
   if (jit_status != JIT_STATUS_ENABLED)
     {
       match_info->matches = pcre2_match (match_info->regex->pcre_re,
-- 
GitLab