From b28a735dfc841d0164e9b7f9193616ae452f5b8c Mon Sep 17 00:00:00 2001
From: Morgan Bartholomew <morgan.bartholomew@jetbrains.com>
Date: Sun, 2 Nov 2025 10:48:05 +1000
Subject: [PATCH] [python] PY-61777 support python 3.11 regex features

(cherry picked from commit 91f2efe47546d0189840d3f3d21da39483de440f)

GitOrigin-RevId: 35c7b142f27130205916522c1bd8c66577be9395
---
 .../lang/regexp/RegExpLanguageHost.java       | 13 +++++-
 .../lang/regexp/RegExpLanguageHosts.java      |  2 +-
 .../python/codeInsight/PythonRegExpHost.java  |  5 ++-
 .../com/jetbrains/python/PyRegexpTest.java    | 43 +++++++++++++++++++
 4 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHost.java b/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHost.java
index 492be753eb4c..8c4a35e71953 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHost.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHost.java
@@ -32,7 +32,18 @@ public interface RegExpLanguageHost {
   }
 
   boolean supportsPerl5EmbeddedComments();
-  boolean supportsPossessiveQuantifiers();
+  /**
+   * @deprecated use `supportsPossessiveQuantifiers(RegExpElement)`
+   */
+  @Deprecated
+  default boolean supportsPossessiveQuantifiers() {
+    return false;
+  }
+
+  default boolean supportsPossessiveQuantifiers(RegExpElement context) {
+    return supportsPossessiveQuantifiers();
+  }
+
   default boolean isDuplicateGroupNamesAllowed(@NotNull RegExpGroup group) {
     return false;
   }
diff --git a/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHosts.java b/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHosts.java
index a1db81af5104..d1b060a2e574 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHosts.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/RegExpLanguageHosts.java
@@ -131,7 +131,7 @@ public final class RegExpLanguageHosts extends ClassExtension<RegExpLanguageHost
 
   public boolean supportsPossessiveQuantifiers(final @Nullable RegExpElement context) {
     final RegExpLanguageHost host = findRegExpHost(context);
-    return host == null || host.supportsPossessiveQuantifiers();
+    return host == null || host.supportsPossessiveQuantifiers(context);
   }
 
   public boolean supportsBoundary(final @Nullable RegExpBoundary boundary) {
diff --git a/python/src/com/jetbrains/python/codeInsight/PythonRegExpHost.java b/python/src/com/jetbrains/python/codeInsight/PythonRegExpHost.java
index 6346ecce88cf..563c4a9baaae 100644
--- a/python/src/com/jetbrains/python/codeInsight/PythonRegExpHost.java
+++ b/python/src/com/jetbrains/python/codeInsight/PythonRegExpHost.java
@@ -32,8 +32,9 @@ public final class PythonRegExpHost implements RegExpLanguageHost {
   }
 
   @Override
-  public boolean supportsPossessiveQuantifiers() {
-    return false;
+  public boolean supportsPossessiveQuantifiers(RegExpElement context) {
+    PsiLanguageInjectionHost host = InjectedLanguageManager.getInstance(context.getProject()).getInjectionHost(context);
+    return host != null && LanguageLevel.forElement(host).isAtLeast(LanguageLevel.PYTHON311);
   }
 
   @Override
diff --git a/python/testSrc/com/jetbrains/python/PyRegexpTest.java b/python/testSrc/com/jetbrains/python/PyRegexpTest.java
index b297ba6c28df..12b9fbbbbb14 100644
--- a/python/testSrc/com/jetbrains/python/PyRegexpTest.java
+++ b/python/testSrc/com/jetbrains/python/PyRegexpTest.java
@@ -1,6 +1,7 @@
 // Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.jetbrains.python;
 
+import com.intellij.idea.TestFor;
 import com.intellij.lang.injection.InjectedLanguageManager;
 import com.intellij.lexer.Lexer;
 import com.intellij.openapi.util.Pair;
@@ -13,6 +14,7 @@ import com.jetbrains.python.codeInsight.regexp.PythonVerboseRegexpLanguage;
 import com.jetbrains.python.codeInsight.regexp.PythonVerboseRegexpParserDefinition;
 import com.jetbrains.python.fixtures.PyLexerTestCase;
 import com.jetbrains.python.fixtures.PyTestCase;
+import com.jetbrains.python.psi.LanguageLevel;
 import org.intellij.lang.regexp.inspection.RegExpRedundantEscapeInspection;
 import org.intellij.lang.regexp.inspection.RegExpSimplifiableInspection;
 import org.jetbrains.annotations.NotNull;
@@ -251,6 +253,42 @@ public class PyRegexpTest extends PyTestCase {
                        "\\w+");
   }
 
+  @TestFor(issues="PY-61777")
+  public void testPossessiveQuantifierSupportedPy3() {
+    runWithLanguageLevel(LanguageLevel.PYTHON311, () ->
+      testHighlighting("""
+                           import re
+                           re.compile("a++ b*+ c?+")""")
+    );
+  }
+
+  @TestFor(issues="PY-61777")
+  public void testPossessiveQuantifierUnsupportedPy3() {
+    runWithLanguageLevel(LanguageLevel.PYTHON310, () ->
+      testHighlighting("""
+                           import re
+                           re.compile("a+<error descr="Nested quantifier in regexp">+</error> b*<error descr="Nested quantifier in regexp">+</error> c?<error descr="Nested quantifier in regexp">+</error>")""")
+    );
+  }
+
+  @TestFor(issues="PY-61777")
+  public void testAtomicGroupSupportedPy3() {
+    runWithLanguageLevel(LanguageLevel.PYTHON311, () ->
+      testHighlighting("""
+                           import re
+                           re.compile("(?>a+)")""")
+    );
+  }
+
+  @TestFor(issues="PY-61777")
+  public void testAtomicGroupUnsupportedPy3() {
+    runWithLanguageLevel(LanguageLevel.PYTHON310, () ->
+      testHighlighting("""
+                           import re
+                           re.compile("<error descr="Atomic groups are not supported in this regex dialect">(?>a+)</error>")""")
+    );
+  }
+
   @Nullable
   @Override
   protected LightProjectDescriptor getProjectDescriptor() {
@@ -275,6 +313,11 @@ public class PyRegexpTest extends PyTestCase {
     myFixture.testHighlighting(true, false, true, "regexp/" + getTestName(true) + ".py");
   }
 
+  private void testHighlighting(String text) {
+    myFixture.configureByText("test.py", text);
+    myFixture.testHighlighting(true, false, true, "test.py");
+  }
+
   private void doTestLexer(final String text, String... expectedTokens) {
     Lexer lexer = new PythonRegexpParserDefinition().createLexer(myFixture.getProject());
     PyLexerTestCase.doLexerTest(text, lexer, expectedTokens);