[M108-LTS][inspector] Create shared regexp object for regex breakpoints

The patch hoists creation of regex object out of the script loop (when
setting breakpoints via an url regexp).

(cherry picked from commit 79b94e8)

Bug: chromium:1422830
Change-Id: Ifc6117ad6c9de41844c2531c6c7d9f8fa4b27627
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4350697
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Original-Commit-Position: refs/branch-heads/11.2@{v8#19}
Cr-Original-Branched-From: 755511a-refs/heads/11.2.214@{#1}
Cr-Original-Branched-From: e6b1cce-refs/heads/main@{#86014}
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4685219
Reviewed-by: Victor Gabriel Savu <vsavu@google.com>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Zakhar Voit <voit@google.com>
Cr-Commit-Position: refs/branch-heads/10.8@{v8#76}
Cr-Branched-From: f1bc03f-refs/heads/10.8.168@{#1}
Cr-Branched-From: 237de89-refs/heads/main@{#83672}

src/inspector/v8-debugger-agent-impl.cc

@@ -501,24 +501,42 @@ Response V8DebuggerAgentImpl::setSkipAllPauses(bool skip) {
   return Response::Success();
 }
 
-static bool matches(V8InspectorImpl* inspector, const V8DebuggerScript& script,
-                    BreakpointType type, const String16& selector) {
-  switch (type) {
-    case BreakpointType::kByUrl:
-      return script.sourceURL() == selector;
-    case BreakpointType::kByScriptHash:
-      return script.hash() == selector;
-    case BreakpointType::kByUrlRegex: {
-      V8Regex regex(inspector, selector, true);
-      return regex.match(script.sourceURL()) != -1;
+namespace {
+
+class Matcher {
+ public:
+  Matcher(V8InspectorImpl* inspector, BreakpointType type,
+          const String16& selector)
+      : type_(type), selector_(selector) {
+    if (type == BreakpointType::kByUrlRegex) {
+      regex_ = std::make_unique<V8Regex>(inspector, selector, true);
     }
-    case BreakpointType::kByScriptId: {
-      return script.scriptId() == selector;
+  }
+
+  bool matches(const V8DebuggerScript& script) {
+    switch (type_) {
+      case BreakpointType::kByUrl:
+        return script.sourceURL() == selector_;
+      case BreakpointType::kByScriptHash:
+        return script.hash() == selector_;
+      case BreakpointType::kByUrlRegex: {
+        return regex_->match(script.sourceURL()) != -1;
+      }
+      case BreakpointType::kByScriptId: {
+        return script.scriptId() == selector_;
+      }
+      default:
+        return false;
     }
-    default:
-      return false;
   }
-}
+
+ private:
+  std::unique_ptr<V8Regex> regex_;
+  BreakpointType type_;
+  const String16& selector_;
+};
+
+}  // namespace
 
 Response V8DebuggerAgentImpl::setBreakpointByUrl(
     int lineNumber, Maybe<String16> optionalURL,
@@ -557,6 +575,9 @@ Response V8DebuggerAgentImpl::setBreakpointByUrl(
     type = BreakpointType::kByScriptHash;
   }
 
+  // Note: This constructor can call into JavaScript.
+  Matcher matcher(m_inspector, type, selector);
+
   String16 condition = optionalCondition.fromMaybe(String16());
   String16 breakpointId =
       generateBreakpointId(type, selector, lineNumber, columnNumber);
@@ -587,7 +608,7 @@ Response V8DebuggerAgentImpl::setBreakpointByUrl(
 
   String16 hint;
   for (const auto& script : m_scripts) {
-    if (!matches(m_inspector, *script.second, type, selector)) continue;
+    if (!matcher.matches(*script.second)) continue;
     if (!hint.isEmpty()) {
       adjustBreakpointLocation(*script.second, hint, &lineNumber,
                                &columnNumber);
@@ -683,6 +704,7 @@ Response V8DebuggerAgentImpl::removeBreakpoint(const String16& breakpointId) {
   if (!parseBreakpointId(breakpointId, &type, &selector)) {
     return Response::Success();
   }
+  Matcher matcher(m_inspector, type, selector);
   protocol::DictionaryValue* breakpoints = nullptr;
   switch (type) {
     case BreakpointType::kByUrl: {
@@ -719,8 +741,7 @@ Response V8DebuggerAgentImpl::removeBreakpoint(const String16& breakpointId) {
   // not Wasm breakpoint.
   std::vector<V8DebuggerScript*> scripts;
   for (const auto& scriptIter : m_scripts) {
-    const bool scriptSelectorMatch =
-        matches(m_inspector, *scriptIter.second, type, selector);
+    const bool scriptSelectorMatch = matcher.matches(*scriptIter.second);
     const bool isInstrumentation =
         type == BreakpointType::kInstrumentationBreakpoint;
     if (!scriptSelectorMatch && !isInstrumentation) continue;
@@ -1874,8 +1895,9 @@ void V8DebuggerAgentImpl::didParseSource(
       int columnNumber = 0;
       parseBreakpointId(breakpointId, &type, &selector, &lineNumber,
                         &columnNumber);
+      Matcher matcher(m_inspector, type, selector);
 
-      if (!matches(m_inspector, *scriptRef, type, selector)) continue;
+      if (!matcher.matches(*scriptRef)) continue;
       String16 condition;
       breakpointWithCondition.second->asString(&condition);
       String16 hint;