Throw StackOverflowError from initMethodStack; add StackOverflowError class and native test

[shai-almog]

Motivation

• Prevent an assertion crash when the VM call stack is exhausted by throwing a proper StackOverflowError so Java code can catch and recover.
• Provide the missing java.lang.StackOverflowError class so the VM can instantiate and throw the error.
• Add an integration test to validate that a stack overflow is thrown and that the VM can continue execution after it is caught.

Description

• Added vm/JavaAPI/src/java/lang/StackOverflowError.java implementing java.lang.VirtualMachineError.
• Updated vm/ByteCodeTranslator/src/nativeMethods.m to include the StackOverflowError header and change initMethodStack to check callStackOffset and call throwException(threadStateData, __NEW_INSTANCE_java_lang_StackOverflowError(threadStateData)) and return instead of asserting.
• Added vm/tests/src/test/java/com/codename1/tools/translator/StackOverflowIntegrationTest.java, a native integration test that compiles a small app which triggers a stack overflow, verifies the StackOverflowError was thrown/caught (STACK_OVERFLOW_OK) and that normal execution (a recursive sum) still works after recovery (RECOVERY_OK:7).

Testing

• No automated tests were executed as part of this change.
• A new automated integration test StackOverflowIntegrationTest was added under vm/tests and will run as part of the VM test suite when the test goals are invoked.
• The change is limited to VM native code, the JavaAPI, and an integration test; CI or a local Maven test run should be used to validate the new test in the full environment.

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Codex Task

[github-actions]

✅ Continuous Quality Report

Test & Coverage

• ✅ Tests: 2292 total, 0 failed, 0 skipped
• 📊 Line coverage: 52.81% [HTML preview] [Download]
  • Lowest covered classes
    • com.codename1.io.rest.RequestBuilder$FetchAsPropertyListActionListener – 0.00%
    • com.codename1.io.rest.RequestBuilder$FetchAsPropertiesActionListener – 0.00%
    • com.codename1.ui.Display$EdtException – 0.00%
    • com.codename1.ui.BrowserWindow$BrowserForm – 0.00%
    • com.codename1.ui.plaf.CSSBorder$LinearGradient – 0.00%
    • com.codename1.io.rest.RequestBuilder$GetAsStringAsyncImplActionListener – 0.00%
    • com.codename1.io.rest.RequestBuilder$GetAsJsonMapActionListener – 0.00%
    • com.codename1.payment.Purchase$SynchronizeReceiptsSyncRunnable – 0.00%
    • com.codename1.io.rest.RequestBuilder$GetAsBytesAsyncImplActionListener – 0.00%
    • com.codename1.io.rest.RequestBuilder$FetchAsJsonMapActionListener – 0.00%

Static Analysis

• SpotBugs [HTML preview] [Download]
  • ❌ ByteCodeTranslator: 122 findings (High: 6, Normal: 84, Low: 32)
    • Top findings
      • High: com/codename1/tools/translator/ByteCodeTranslator.java:579 – Found reliance on default encoding in com.codename1.tools.translator.ByteCodeTranslator.writeCmakeProject(File, File, String): new java.io.FileWriter(File) (rule: DM_DEFAULT_ENCODING)
      • High: com/codename1/tools/translator/ByteCodeTranslator.java:660 – Found reliance on default encoding in com.codename1.tools.translator.ByteCodeTranslator.readFileAsStringBuilder(File): new String(byte[]) (rule: DM_DEFAULT_ENCODING)
      • High: com/codename1/tools/translator/ByteCodeTranslator.java:690 – Found reliance on default encoding in com.codename1.tools.translator.ByteCodeTranslator.replaceInFile(File, String[]): new java.io.FileWriter(File) (rule: DM_DEFAULT_ENCODING)
      • …and 119 more
  • ❌ android: 444 findings (High: 42, Normal: 197, Low: 205)
    • Top findings
      • High: CodenameOne/src/com/codename1/impl/CodenameOneThread.java:48 – com.codename1.impl.CodenameOneThread.STACK_FRAME_SIZE isn't final but should be (rule: MS_SHOULD_BE_FINAL)
      • High: com/codename1/impl/android/AndroidImplementation.java:1059 – Write to static field com.codename1.impl.android.AndroidImplementation.context from instance method com.codename1.impl.android.AndroidImplementation.setContext(Context) (rule: ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD)
      • High: com/codename1/impl/android/AndroidImplementation.java:10706 – com.codename1.impl.android.AndroidImplementation.performBackgroundFetch(boolean) might ignore java.lang.Exception (rule: DE_MIGHT_IGNORE)
      • …and 441 more
  • ❌ codenameone-maven-plugin: 537 findings (High: 37, Normal: 327, Low: 173)
    • Top findings
      • High: com/codename1/builders/AndroidGradleBuilder.java:1553 – Found reliance on default encoding in com.codename1.builders.AndroidGradleBuilder.build(File, BuildRequest): String.getBytes() (rule: DM_DEFAULT_ENCODING)
      • High: com/codename1/builders/AndroidGradleBuilder.java:1982 – Found reliance on default encoding in com.codename1.builders.AndroidGradleBuilder.build(File, BuildRequest): new java.io.FileReader(File) (rule: DM_DEFAULT_ENCODING)
      • High: com/codename1/builders/AndroidGradleBuilder.java:3989 – Found reliance on default encoding in com.codename1.builders.AndroidGradleBuilder.extract(InputStream, File, String): String.getBytes() (rule: DM_DEFAULT_ENCODING)
      • …and 534 more
  • ✅ core-unittests: 0 findings (no issues)
  • ❌ ios: 127 findings (High: 5, Normal: 75, Low: 47)
    • Top findings
      • High: com/codename1/impl/ios/IOSImplementation.java:1218 – com.codename1.impl.ios.IOSImplementation.isDarkMode() has Boolean return type and returns explicit null (rule: NP_BOOLEAN_RETURN_NULL)
      • High: com/codename1/impl/ios/IOSImplementation.java:127 – com.codename1.impl.ios.IOSImplementation.nativeInstance isn't final but should be (rule: MS_SHOULD_BE_FINAL)
      • High: com/codename1/impl/ios/IOSImplementation.java:212 – Write to static field com.codename1.impl.ios.IOSImplementation.instance from instance method com.codename1.impl.ios.IOSImplementation.init(Object) (rule: ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD)
      • …and 124 more
• ✅ PMD: 0 findings (no issues) [Report archive]
• ✅ Checkstyle: 0 findings (no issues) [Report archive]

Generated automatically by the PR CI workflow.

[shai-almog]

Compared 30 screenshots: 30 matched.
✅ Native Android screenshot tests passed.

Benchmark Results

• VM Translation Time: 336 seconds
• Compilation Time: 350 seconds

Detailed Performance Metrics

Metric	Duration
Build Time Statistics
Setup & Unzip	31760 ms
Extract Extensions	29 ms
Google Services Setup	4 ms
Scan Classes	940 ms
Extract Libs	1281 ms
Inject Build Hints	80 ms
Generate Unit Tests	6 ms
Generate Stubs	2232 ms
Compile Stubs	2362 ms
Generate Icons	992 ms
Prepare ParparVM	240 ms
ParparVM Execution	185476 ms
Post-VM Setup	254 ms
CocoaPods	6244 ms
Finalize	29 ms
Total Time	231930 msMaven Overhead : 105000 ms
CocoaPods Install (Script)	2000 ms
Simulator Boot	270000 ms
Simulator Boot (Run)	6000 ms
App Install	19000 ms
App Launch	17000 ms
Test Execution	264000 ms