René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Integrate C-Reduce for Automatic Test Case Reduction","articleBody":"### Problem Statement\n\nCurrently, SQLancer users must manually capture database states and write interestingness scripts when using C-Reduce for test case minimization. This process is error-prone and limits automation capabilities.\n\n### Implementation Plan\n\n1. **Add CLI option (`MainOptions.java`):**\n\n```java\n@Parameter(names = \"--use-creduce\", description = \"EXPERIMENTAL Attempt to reduce queries using c-reduce\")\nprivate boolean useCReduce = false; // NOPMD\n```\n\n2. **Modify Exception Handling (`Main.java`):**\n\nInside `executeMain(...)`: extend the existing `catch (Throwable reduce)` block.\n\n```java\ntry {\n    ...\n} catch (Throwable reduce) {\n    reduce.printStackTrace();\n    executor.getStateToReproduce().exception = reduce.getMessage();\n    executor.getLogger().logFileWriter = null;\n    executor.getLogger().logException(reduce, executor.getStateToReproduce());\n    \n    if (options.useCreduce()) {\n        Reducer\u003cG\u003e reducer = new CReducer\u003c\u003e(provider);\n        creducer.reduce(/* state, reduce, ... */);\n    }\n    return false;\n}\n```\n\n3. **CReducer.reduce(...) should:**\n   - Generate `databasex.sql`: Dump all statements from `state.getStatements()`, and append the failing statement (from `reduce.detailMessage`)\n   - Generate `databasex.sh` (interestingness script): Extract the error substring from `reduce.cause.detailMessage` (e.g., from `[SQLITE_CORRUPT]  The database disk image is malformed (database disk image is malformed)` grab `database disk image is malformed`), then can generate a script like: `sqlite3 databasex.sql 2\u003e\u00261 | grep -zq \"database disk image is malformed\"`.\n   - Invoke C-reduce by `ProcessBuilder`, like: `Process p = new ProcessBuilder(\"creduce\", \"databasex.sh\", \"databasex.sql\").start();`.\n\n### Questions\n\n- Is this design sensible? Any obvious pitfalls?\n- How to handle missing or mismatched SQLite versions? The interestingness script may fail.\n- This approach only works for SQLite. How can we generalize it to support other DBMSs?\n\n@mrigger @KabilanMA Could you review this design before implementation? Thanks!","author":{"url":"https://github.com/jinhuix","@type":"Person","name":"jinhuix"},"datePublished":"2025-06-06T06:58:55.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/1241/sqlancer/issues/1241"}