From dcd8e05f0cf2d6be8996b5e979544ffead4d18bd Mon Sep 17 00:00:00 2001
From: Andre Wachsmuth <sensenmann5@gmail.com>
Date: Sat, 27 Apr 2024 18:40:58 +0100
Subject: [PATCH] Make regexp execution loop interruptible #1189 (#1440)

* Make regexp execution loop interruptible #1189

Uses Thread.currentThread.isInterrupted() so that the interruption flag remains set to true,
we only terminate the RegExp evaluation loop, but other (potentially third-party calling)
code may still have to check for the interrupted flag to stop its execution as well.

I also added a test with a long-running regexp that fails without the interrupt check.

Co-authored-by: Andre Wachsmuth <awa@xima.de>
---
 src/org/mozilla/javascript/regexp/NativeRegExp.java      | 9 ++++++---
 .../javascript/tests/ObserveInstructionCountTest.java    | 7 +++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/org/mozilla/javascript/regexp/NativeRegExp.java b/src/org/mozilla/javascript/regexp/NativeRegExp.java
index 2dadc213dd..c776c45fda 100644
--- a/src/org/mozilla/javascript/regexp/NativeRegExp.java
+++ b/src/org/mozilla/javascript/regexp/NativeRegExp.java
@@ -1857,7 +1857,8 @@ private static int simpleMatch(
         return -1;
     }
 
-    private static boolean executeREBytecode(REGlobalData gData, String input, int end) {
+    private static boolean executeREBytecode(
+            Context cx, REGlobalData gData, String input, int end) {
         int pc = 0;
         byte[] program = gData.regexp.program;
         int continuationOp = REOP_END;
@@ -1887,6 +1888,7 @@ private static boolean executeREBytecode(REGlobalData gData, String input, int e
         }
 
         for (; ; ) {
+            ScriptRuntime.addInstructionCount(cx, 5);
 
             if (reopIsSimple(op)) {
                 int match = simpleMatch(gData, input, op, program, pc, end, true);
@@ -2316,6 +2318,7 @@ && simpleMatch(gData, input, op, program, pc, end, false) < 0) {
     }
 
     private static boolean matchRegExp(
+            Context cx,
             REGlobalData gData,
             RECompiled re,
             String input,
@@ -2369,7 +2372,7 @@ && upcase(matchCh) == upcase((char) anchorCh))) {
             for (int j = 0; j < re.parenCount; j++) {
                 gData.parens[j] = -1L;
             }
-            boolean result = executeREBytecode(gData, input, end);
+            boolean result = executeREBytecode(cx, gData, input, end);
 
             gData.backTrackStackTop = null;
             gData.stateStackTop = null;
@@ -2403,7 +2406,7 @@ Object executeRegExp(
         //
         // Call the recursive matcher to do the real work.
         //
-        boolean matches = matchRegExp(gData, re, str, start, end, res.multiline);
+        boolean matches = matchRegExp(cx, gData, re, str, start, end, res.multiline);
         if (!matches) {
             if (matchType != PREFIX) return null;
             return Undefined.instance;
diff --git a/testsrc/org/mozilla/javascript/tests/ObserveInstructionCountTest.java b/testsrc/org/mozilla/javascript/tests/ObserveInstructionCountTest.java
index a83b351c6b..72d34115ea 100644
--- a/testsrc/org/mozilla/javascript/tests/ObserveInstructionCountTest.java
+++ b/testsrc/org/mozilla/javascript/tests/ObserveInstructionCountTest.java
@@ -118,4 +118,11 @@ public void forever() {
         String source = "for(;;);";
         baseCase(source);
     }
+
+    @Test
+    public void longRunningRegExp() {
+        String source =
+                "/(.*){1,32000}[bc]/.test(\"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\");";
+        baseCase(source);
+    }
 }