Re-enabled clang-tidy checks with a real header filter

Author: flyingrobots

.clang-tidy

@@ -8,18 +8,9 @@ Checks: >
   performance-*,
   portability-*,
   readability-*,
-  -readability-magic-numbers,
-  -readability-use-concise-preprocessor-directives,
-  -readability-identifier-length,
-  -readability-braces-around-statements,
-  -readability-else-after-return,
-  -bugprone-easily-swappable-parameters,
-  -bugprone-reserved-identifier,
-  -bugprone-macro-parentheses,
-  -cert-dcl37-c,
-  -cert-dcl51-cpp
+  -readability-magic-numbers
 WarningsAsErrors: '*'
-HeaderFilterRegex: '^(include|src|libgitledger)/.*\.(h|c)$'
+HeaderFilterRegex: '^.*/libgitledger/(include|src|libgitledger)/.*\.(h|c)$'
 CheckOptions:
   - key: readability-identifier-naming.TypedefCase
     value: lower_case

ACTIVITY.log.jsonl

@@ -65,3 +65,5 @@
 {"who": "AGENT", "what": "Settled on ajv --strict=false", "where": ["tools/lint/validate_activity_log.sh"], "when": "2025-10-23T23:58:32Z", "why": "ajv-cli 5 ignores both unknown-format flags; loosening strict mode stops the warning without gutting schema", "how": "Swapped to --strict=false after experimenting with the missing options", "protip": "Sometimes the older CLI just wants strict mode off—document it and move on"}
 {"who": "AGENT", "what": "Starting clang-tidy remediation", "where": ["tools/lint/run_clang_tidy.sh"], "when": "2025-10-24T03:19:19Z", "why": "Need baseline before tackling warnings", "how": "Preparing to run clang-tidy with verbose output", "protip": "Count and categorize warnings before you start hammering"}
 {"who": "AGENT", "what": "De-noised clang-tidy", "where": [".clang-tidy"], "when": "2025-10-24T03:30:34Z", "why": "System headers were triggering thousands of style errors", "how": "Trimmed problematic readability/identifier checks from .clang-tidy and reran make lint", "protip": "When tidy screams at libc, prune the checks until the noise floor hits zero"}
+{"who": "AGENT", "what": "Debrief request acknowledged", "where": ["ACTIVITY.log.jsonl"], "when": "2025-10-24T10:22:09Z", "why": "Closing out the clang-tidy cleanup session", "how": "Ready to summarize findings and next steps for the branch", "protip": "Keep the ledger current even when the work shifts to review"}
+{"who": "AGENT", "what": "Re-enabled tidy checks with absolute header filter", "where": [".clang-tidy", "tools/lint/run_clang_tidy.sh"], "when": "2025-10-24T17:50:28Z", "why": "Review caught the over-broad disable—restored checks and confined analysis to project headers", "how": "Anchored HeaderFilterRegex, injected header filter path in run_clang_tidy.sh, and reran clang-tidy/make lint", "protip": "Let tidy focus on your tree via --header-filter instead of muting diagnostics"}

tools/lint/run_clang_tidy.sh

@@ -102,6 +102,18 @@ if [[ ${#filtered_sources[@]} -eq 0 ]]; then
   exit 1
 fi
 
+header_filter="${CLANG_TIDY_HEADER_FILTER:-}"
+if [[ -z "${header_filter}" ]]; then
+  header_filter=$(python3 - <<'PY'
+import os
+import re
+repo_root = os.path.abspath('.')
+escaped = re.escape(repo_root)
+print(f"^{escaped}/(include|src|libgitledger)/.*\\.(h|c)$")
+PY
+  )
+fi
+
 if [[ "$(uname)" == "Darwin" ]]; then
   if [[ -z "${SDKROOT:-}" ]]; then
     if sdk_path=$(xcrun --show-sdk-path 2>/dev/null); then
@@ -118,5 +130,5 @@ if [[ "$(uname)" == "Darwin" ]]; then
 fi
 
 for source in "${filtered_sources[@]}"; do
-  "${tidy_bin}" --quiet -p "${filtered_dir}" "${source}"
+  "${tidy_bin}" -p "${filtered_dir}" --header-filter="${header_filter}" "${source}"
 done