feat(lint): add clang-tidy static analysis configuration

Add clang-tidy setup for detecting bugs, style issues, and code smells:
- .clang-tidy: enable bugprone, cert, clang-analyzer, performance,
  portability, and readability checks with sensible exclusions
- scripts/clang-tidy.sh: wrapper script that auto-generates
  compile_commands.json via bear if needed

Author: mceachen

.clang-tidy

@@ -0,0 +1,44 @@
+---
+# clang-tidy configuration for sqlite-vec
+# See: https://clang.llvm.org/extra/clang-tidy/
+
+Checks: >
+  -*,
+  bugprone-*,
+  cert-*,
+  clang-analyzer-*,
+  concurrency-*,
+  misc-*,
+  performance-*,
+  portability-*,
+  readability-*,
+  -readability-identifier-length,
+  -readability-magic-numbers,
+  -readability-function-cognitive-complexity,
+  -misc-no-recursion,
+  -cert-dcl37-c,
+  -cert-dcl51-cpp,
+  -readability-isolate-declaration,
+  -readability-identifier-naming,
+  -clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling
+
+# Don't treat warnings as errors (informational only)
+WarningsAsErrors: ''
+
+# Header filter (analyze headers in this project)
+HeaderFilterRegex: '.*sqlite-vec\.h'
+
+# Check options
+CheckOptions:
+  - key: readability-identifier-naming.FunctionCase
+    value: lower_case
+  - key: readability-identifier-naming.VariableCase
+    value: lower_case
+  - key: readability-identifier-naming.ParameterCase
+    value: lower_case
+  - key: readability-function-size.LineThreshold
+    value: '200'
+  - key: readability-function-size.StatementThreshold
+    value: '150'
+  - key: cppcoreguidelines-avoid-do-while.IgnoreMacros
+    value: 'true'

scripts/clang-tidy.sh

@@ -0,0 +1,113 @@
+#!/bin/bash
+#
+# clang-tidy static analysis for sqlite-vec
+# Detects potential bugs, style issues, and code smells
+#
+# Usage: ./scripts/clang-tidy.sh
+# Or:    make lint-clang-tidy
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" &>/dev/null && pwd)"
+ROOT_DIR="$(dirname "$SCRIPT_DIR")"
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+BLUE='\033[0;34m'
+NC='\033[0m' # No Color
+
+echo -e "${BLUE}=== clang-tidy Static Analysis ===${NC}"
+
+# Check if clang-tidy is available
+if ! command -v clang-tidy &>/dev/null; then
+    echo -e "${YELLOW}Warning: clang-tidy not found.${NC}"
+    echo "Install with:"
+    echo "  Linux: sudo apt-get install clang-tidy"
+    echo "  macOS: brew install llvm"
+    exit 0
+fi
+
+echo "Using: $(clang-tidy --version | head -1)"
+
+# Check if compile_commands.json exists
+if [ ! -f "$ROOT_DIR/compile_commands.json" ]; then
+    echo -e "${YELLOW}compile_commands.json not found. Generating with bear...${NC}"
+
+    # Check if bear is available
+    if ! command -v bear &>/dev/null; then
+        echo -e "${YELLOW}Warning: bear not found. Install with:${NC}"
+        echo "  Linux: sudo apt-get install bear"
+        echo "  macOS: brew install bear"
+        echo ""
+        echo -e "${YELLOW}Running clang-tidy without compile_commands.json (less accurate)${NC}"
+    else
+        # Generate compile_commands.json
+        echo "Generating compile_commands.json with bear..."
+        cd "$ROOT_DIR"
+        if bear -- make clean all >/dev/null 2>&1; then
+            echo -e "${GREEN}Generated compile_commands.json${NC}"
+        else
+            echo -e "${YELLOW}Failed to generate compile_commands.json, continuing without it${NC}"
+            rm -f "$ROOT_DIR/compile_commands.json"
+        fi
+    fi
+fi
+
+# Output file
+OUTPUT_FILE="$ROOT_DIR/clang-tidy-output.txt"
+rm -f "$OUTPUT_FILE"
+
+# Run clang-tidy
+set +e
+if [ -f "$ROOT_DIR/compile_commands.json" ]; then
+    clang-tidy \
+        -p="$ROOT_DIR" \
+        "$ROOT_DIR/sqlite-vec.c" \
+        2>&1 | tee "$OUTPUT_FILE"
+    TIDY_EXIT=${PIPESTATUS[0]}
+else
+    # Fallback: run without compile_commands.json
+    clang-tidy \
+        "$ROOT_DIR/sqlite-vec.c" \
+        -- \
+        -I"$ROOT_DIR/vendor/" \
+        -DSQLITE_CORE \
+        -DSQLITE_VEC_STATIC \
+        2>&1 | tee "$OUTPUT_FILE"
+    TIDY_EXIT=${PIPESTATUS[0]}
+fi
+set -e
+
+echo ""
+
+# Count warnings and errors
+WARNING_COUNT=$(grep -c "warning:" "$OUTPUT_FILE" 2>/dev/null || echo "0")
+ERROR_COUNT=$(grep -c "error:" "$OUTPUT_FILE" 2>/dev/null || echo "0")
+
+echo -e "${BLUE}=== clang-tidy Summary ===${NC}"
+echo "  Warnings: $WARNING_COUNT"
+echo "  Errors:   $ERROR_COUNT"
+
+if [[ "$WARNING_COUNT" -eq 0 && "$ERROR_COUNT" -eq 0 ]]; then
+    echo -e "\n${GREEN}PASS: No issues found by clang-tidy${NC}"
+    rm -f "$OUTPUT_FILE"
+    exit 0
+else
+    echo -e "\n${YELLOW}Issues found. See $OUTPUT_FILE for details.${NC}"
+
+    # Show top issues
+    if [[ "$WARNING_COUNT" -gt 0 ]]; then
+        echo -e "\n${YELLOW}Top warnings:${NC}"
+        grep "warning:" "$OUTPUT_FILE" | head -10
+    fi
+
+    if [[ "$ERROR_COUNT" -gt 0 ]]; then
+        echo -e "\n${RED}Errors:${NC}"
+        grep "error:" "$OUTPUT_FILE" | head -10
+    fi
+
+    # Don't fail the build for clang-tidy warnings (informational only)
+    exit 0
+fi