spike: macOS opencv snapshot workflow (headless core/imgproc/imgcodecs) + gen_descriptor ISA_RE neon

Author: Sunrisepeak

.github/workflows/snapshot-macos-opencv.yml

@@ -0,0 +1,73 @@
+# TEMP spike: generate a macOS-arm64 (headless core/imgproc/imgcodecs) config
+# snapshot for compat.opencv on a real macos-15 runner, then emit the descriptor
+# via gen_descriptor.py and upload it as an artifact. Two-phase (like the ffmpeg
+# snapshot): this captures + generates; a follow-up build spike validates it.
+name: snapshot-macos-opencv
+on:
+  workflow_dispatch:
+  push:
+    branches: [spike/opencv-macos-snapshot]
+jobs:
+  snapshot:
+    runs-on: macos-15
+    timeout-minutes: 90
+    steps:
+      - uses: actions/checkout@v4
+      - name: install toolchain
+        run: brew install cmake ninja
+      - name: fetch + extract OpenCV 5.0.0
+        run: |
+          set -eux
+          V=5.0.0
+          SHA=b0528f5a1d379d59d4701cb28c36e22214cc51cf64594e5b56f2d3e6c0233095
+          curl -L -fsS -o opencv.tar.gz "https://github.com/opencv/opencv/archive/refs/tags/$V.tar.gz"
+          echo "$SHA  opencv.tar.gz" | shasum -a 256 -c -
+          tar -xzf opencv.tar.gz
+          echo "SRC=$PWD/opencv-$V" >> "$GITHUB_ENV"
+      - name: cmake configure (headless, aarch64, no external probes)
+        run: |
+          set -eux
+          cmake -G Ninja -S "$SRC" -B bld \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DBUILD_LIST=core,imgproc,imgcodecs \
+            -DBUILD_SHARED_LIBS=OFF \
+            -DBUILD_ZLIB=ON -DBUILD_PNG=ON -DBUILD_JPEG=ON \
+            -DWITH_TIFF=OFF -DWITH_WEBP=OFF -DWITH_OPENJPEG=OFF -DWITH_JASPER=OFF \
+            -DWITH_OPENEXR=OFF -DWITH_AVIF=OFF -DWITH_JPEGXL=OFF -DWITH_IMGCODEC_GIF=OFF \
+            -DWITH_OPENCL=OFF -DWITH_IPP=OFF -DWITH_LAPACK=OFF -DWITH_EIGEN=OFF -DWITH_ITT=OFF \
+            -DWITH_QT=OFF -DWITH_OPENGL=OFF -DWITH_FFMPEG=OFF -DWITH_GSTREAMER=OFF \
+            -DWITH_AVFOUNDATION=OFF -DWITH_V4L=OFF -DWITH_OBSENSOR=OFF \
+            -DWITH_PROTOBUF=OFF -DWITH_CAROTENE=OFF -DWITH_FLATBUFFERS=OFF \
+            -DWITH_UNIFONT=OFF -DWITH_ADE=OFF \
+            -DBUILD_TESTS=OFF -DBUILD_PERF_TESTS=OFF -DBUILD_EXAMPLES=OFF \
+            -DBUILD_opencv_apps=OFF -DBUILD_JAVA=OFF -DBUILD_opencv_python3=OFF
+      - name: reference build (materialize generators; -k keeps going past ICEs)
+        run: ninja -C bld -k 0 > bld/ninja-build.log 2>&1 || true
+      - name: dump compile commands + gen descriptor
+        run: |
+          set -eux
+          ninja -C bld -t commands > bld/ninja-cmds.log
+          python3 tools/compat-opencv/gen_descriptor.py \
+            "$SRC" bld 5.0.0 \
+            b0528f5a1d379d59d4701cb28c36e22214cc51cf64594e5b56f2d3e6c0233095 \
+            compat.opencv.macgen.lua
+          # retarget the single-platform emission to macosx + a spike name
+          sed -e 's/^        linux = {{/        macosx = {{/' \
+              -e 's/^        linux = {/        macosx = {/' \
+              -e 's/name        = "compat.opencv"/name        = "compat.opencvmac"/' \
+              compat.opencv.macgen.lua > compat.opencvmac.lua
+          echo "=== descriptor head ==="; head -60 compat.opencvmac.lua
+          echo "=== sanity: aarch64 SIMD dispatch files present? ==="
+          grep -oE '\.(neon[a-z0-9_]*|fp16)\.cpp' bld/ninja-cmds.log | sort | uniq -c || true
+      - name: upload artifact
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: opencv-macos-snapshot
+          path: |
+            compat.opencvmac.lua
+            compat.opencv.macgen.lua
+            bld/cvconfig.h
+            bld/cv_cpu_config.h
+            bld/ninja-cmds.log
+            bld/ninja-build.log

tools/compat-opencv/gen_descriptor.py

@@ -86,7 +86,12 @@
 assert compiles, "no compile commands parsed"
 print(f"parsed {len(compiles)} compiles")
 
-ISA_RE = re.compile(r"\.(sse4_1|sse4_2|avx512_skx|avx2|avx|fp16)\.cpp$")
+# x86 dispatch suffixes + aarch64 NEON dispatch suffixes (macOS/arm). Longest
+# alternatives first so `.neon_dotprod.cpp` isn't shadowed by `neon` (the
+# trailing `\.cpp$` anchor already forces a full match, but keep it explicit).
+ISA_RE = re.compile(
+    r"\.(sse4_1|sse4_2|avx512_skx|avx2|avx|fp16"
+    r"|neon_dotprod|neon_fp16|neon_bf16|neon_i8mm|neon)\.cpp$")
 MODS = ("core", "imgproc", "imgcodecs", "highgui", "videoio", "flann", "geometry", "dnn")
 # groups that belong to the additive `dnn` feature (sources gated; flags
 # entries stay unconditional — harmless when the feature is off)