feat(#460): Binary-size regression gate

.github/workflows/ci-main.yml

@@ -132,6 +132,11 @@ jobs:
         if: runner.os != 'Windows'
         run: meson test -C builddir --print-errorlogs
 
+      - name: Check binary size
+        if: runner.os == 'Linux' && matrix.compiler == 'gcc'
+        continue-on-error: true
+        run: scripts/ci/check-text-size.sh builddir/libwirelog.so
+
       - name: Publish results
         if: always()
         shell: bash

.github/workflows/ci-pr.yml

@@ -117,6 +117,14 @@ jobs:
           call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
           meson test -C builddir --print-errorlogs
 
+      # =======================================================================
+      # Binary size regression gate (Issue #460)
+      # Only runs on Linux GCC (reference platform for .text baseline)
+      # =======================================================================
+      - name: Check binary size
+        if: runner.os == 'Linux' && matrix.compiler == 'gcc'
+        run: scripts/ci/check-text-size.sh builddir/libwirelog.so
+
       # =======================================================================
       # Phase 3: Sanitizers (ASan + UBSan) — runs on same platform after build
       # Linux: GCC + Clang; macOS: Clang (Windows: skipped)

scripts/ci/check-text-size.sh

@@ -0,0 +1,96 @@
+#!/bin/sh
+# check-text-size.sh - Binary-size regression gate for libwirelog (Issue #460)
+#
+# Computes .text section size of the built library, compares against
+# the committed baseline in tests/baseline_size.txt, and fails if
+# growth exceeds the 5120-byte budget (section 14, Issue #446).
+#
+# Usage: scripts/ci/check-text-size.sh <path-to-library>
+# Example: scripts/ci/check-text-size.sh builddir/libwirelog.so
+#
+# To update the baseline after legitimate growth:
+#   echo <new-size> > tests/baseline_size.txt
+
+set -e
+
+THRESHOLD=5120
+SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
+REPO_ROOT=$(cd "$SCRIPT_DIR/../.." && pwd)
+BASELINE_FILE="$REPO_ROOT/tests/baseline_size.txt"
+
+die() {
+    printf 'error: %s\n' "$1" >&2
+    exit 1
+}
+
+if [ $# -lt 1 ]; then
+    die "usage: $0 <path-to-library>"
+fi
+
+LIB="$1"
+
+if [ ! -f "$LIB" ]; then
+    die "library not found: $LIB"
+fi
+
+# Extract .text section size (platform-aware)
+extract_text_size() {
+    case "$(uname -s)" in
+        Linux)
+            size --format=sysv "$1" | awk '/^\.text[[:space:]]/ { print $2 }'
+            ;;
+        Darwin)
+            size -m "$1" | awk '/Section __text:/ { print $3 }'
+            ;;
+        *)
+            die "unsupported platform: $(uname -s)"
+            ;;
+    esac
+}
+
+TEXT_SIZE=$(extract_text_size "$LIB")
+
+if [ -z "$TEXT_SIZE" ]; then
+    die "could not extract .text section size from $LIB"
+fi
+
+# Validate extracted size is numeric
+case "$TEXT_SIZE" in
+    ''|*[!0-9]*)
+        die "non-numeric .text size extracted: '$TEXT_SIZE'"
+        ;;
+esac
+
+# Read baseline
+if [ ! -f "$BASELINE_FILE" ]; then
+    die "baseline file not found: $BASELINE_FILE"
+fi
+
+BASELINE=$(tr -d '[:space:]' < "$BASELINE_FILE")
+
+case "$BASELINE" in
+    ''|*[!0-9]*)
+        die "invalid baseline value in $BASELINE_FILE: '$BASELINE'"
+        ;;
+esac
+
+# Compute delta (positive = growth, negative = shrinkage)
+DELTA=$((TEXT_SIZE - BASELINE))
+
+printf '.text size:  %d bytes\n' "$TEXT_SIZE"
+printf 'baseline:    %d bytes\n' "$BASELINE"
+if [ "$DELTA" -ge 0 ]; then
+    printf 'delta:       +%d bytes\n' "$DELTA"
+else
+    printf 'delta:       %d bytes\n' "$DELTA"
+fi
+printf 'threshold:   +%d bytes\n' "$THRESHOLD"
+
+if [ "$DELTA" -gt "$THRESHOLD" ]; then
+    printf '\nFAIL: .text growth (+%d) exceeds %d-byte budget\n' "$DELTA" "$THRESHOLD" >&2
+    printf 'To update the baseline after a legitimate change:\n' >&2
+    printf '  echo %d > tests/baseline_size.txt\n' "$TEXT_SIZE" >&2
+    exit 1
+fi
+
+printf '\nPASS: .text delta within budget\n'