build: compile yyjson with -Og in debug builds

[edsiper]

yyjson's reader can generate an oversized stack frame in SIMD-enabled Debug/RelWithDebInfo builds, which exceeds Fluent Bit's default coroutine stack budget and can break JSON parsing in coroutine paths such as filter_kubernetes.

This change forces -Og for the yyjson target in Debug and RelWithDebInfo builds for GNU/Clang/ Intel compilers. It preserves debug symbols while shrinking yyjson_read_opts() from 26112 bytes to 1472 bytes in the affected build, avoiding coroutine stack overflows without changing parser behavior.

(cc: @cosmo0920 )

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Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

Summary by CodeRabbit

• Chores
  • Adjusted build behavior for Debug and RelWithDebInfo builds with GNU/Clang/Intel compilers to use less aggressive optimization for a bundled dependency, improving debug reliability and compilation performance.
  • When the bundled dependency is present, code coverage is disabled to prevent inconsistent coverage results.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

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Reviewing files that changed from the base of the PR and between 930f191 and babc9b7.

📒 Files selected for processing (1)

• CMakeLists.txt

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📝 Walkthrough

Walkthrough

A CMake conditional was added to the bundled yyjson subdirectory: when the yyjson target exists, coverage is disabled and the compiler is GNU/Clang/AppleClang/Intel, the build applies a target-scoped -Og compile option for Debug and RelWithDebInfo configurations.

Changes

Cohort / File(s)	Summary
Build Configuration CMakeLists.txt	Added conditional to disable coverage and apply target-scoped -Og compile option to the bundled yyjson target for GNU/Clang/AppleClang/Intel compilers in Debug and RelWithDebInfo builds. No other targets or configurations changed.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• pack: use SIMD JSON when available - default to all #11562 — Adjusts build flags for the bundled yyjson target and relates to SIMD JSON packing changes.

Suggested reviewers

• niedbalski
• patrick-stephens
• celalettin1286
• cosmo0920

Poem

🐰 A tiny flag hops into place,
Debug lines snug in an optimization embrace,
yyjson trimmed for a gentler tune,
Compilers nod beneath the moon,
Build-time carrots for a sleeker race 🥕

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly and clearly summarizes the main change: applying -Og optimization to yyjson in debug builds, which is the core objective of the CMakeLists.txt modification.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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• Create PR with unit tests
• Commit unit tests in branch simd-coro

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@CMakeLists.txt`:
- Around line 668-674: The compiler check for applying debug/optimization flags
to target_compile_options(yyjson ...) omits AppleClang, so macOS system builds
won't get the stack-shrinking -Og adjustment; update the CMAKE_C_COMPILER_ID
MATCHES expression used in the if(...) guarding target_compile_options for the
yyjson target to include "AppleClang" (make it match "GNU|Clang|AppleClang") so
the -Og option is applied on AppleClang debug/RelWithDebInfo configurations.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

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Run ID: df6311c0-c7c1-46b5-b689-04e194a9d42f

📥 Commits

Reviewing files that changed from the base of the PR and between d257e00 and 930f191.

📒 Files selected for processing (1)

• CMakeLists.txt

[chatgpt-codex-connector]

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Reviewed commit: 930f191ee2

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[chatgpt-codex-connector]

Skip the -Og override when coverage is enabled

When Fluent Bit is configured with -DFLB_COVERAGE=On, CMakeLists.txt:467-472 explicitly adds -O0 --coverage and forces CMAKE_BUILD_TYPE=Debug, and that mode is exercised in .github/workflows/unit-tests.yaml:52. This new $<CONFIG:Debug> branch still appends -Og for yyjson, so the parser is no longer built with the project’s intended coverage flags (the last optimization flag wins for GCC/Clang). In that configuration the coverage job will collect different, less faithful line/branch coverage for yyjson than before, even though only interactive debug builds needed the stack-frame workaround.

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