Add support for building ARM64 iOS wheels on CI (#181)

* Add support for building ARM64 iOS wheels on CI

* s/skip/skipif/

* Bump ios jobs to macos-15 and build-time Python 3.13

* Restore the `platform` field in the ios matrix, it's used by libffi downloads

* surewhynot

Co-authored-by: 🇺🇦 Sviatoslav Sydorenko (Святослав Сидоренко) <[email protected]>

* Revert "surewhynot"

This reverts commit c4e3a87.

* Pin to macos-14

Co-authored-by: Russell Keith-Magee <[email protected]>

* Attempt #2 to forego tar.gz extraction

* Be specific about what's raised in xfail

* Revert "Attempt #2 to forego tar.gz extraction"

This reverts commit a0cf74a.

---------

Co-authored-by: 🇺🇦 Sviatoslav Sydorenko (Святослав Сидоренко) <[email protected]>
Co-authored-by: Russell Keith-Magee <[email protected]>

Author: 3 people

.github/workflows/ci.yaml

@@ -112,7 +112,7 @@ jobs:
           - { spec: cp314-manylinux_aarch64, arch: aarch64 }
           - { spec: cp314t-manylinux_aarch64, arch: aarch64 }
 
-            # aarch64 musllinux
+          # aarch64 musllinux
           - { spec: cp39-musllinux_aarch64, arch: aarch64, omit: ${{ env.skip_ci_redundant_jobs }} }
           - { spec: cp310-musllinux_aarch64, arch: aarch64, omit: ${{ env.skip_ci_redundant_jobs }} }
           - { spec: cp311-musllinux_aarch64, arch: aarch64, omit: ${{ env.skip_ci_redundant_jobs }} }
@@ -379,8 +379,111 @@ jobs:
         if-no-files-found: error
       if: ${{ env.skip_artifact_upload != 'true' }}
 
+  make_ios_matrix:
+    runs-on: ubuntu-24.04
+    outputs:
+      matrix_json: ${{ steps.make_matrix.outputs.matrix_json }}
+    steps:
+    - uses: actions/checkout@v4
+    - name: make a matrix
+      id: make_matrix
+      uses: ./.github/actions/dynamatrix
+      with:
+        matrix_yaml: |
+          include:
+          # arm64 iOS device
+          - { spec: cp313-ios_arm64_iphoneos, platform: 'iphoneos' }
+          - { spec: cp314-ios_arm64_iphoneos, platform: 'iphoneos' }
+
+          # arm64 iOS simulator
+          - { spec: cp313-ios_arm64_iphonesimulator, platform: 'iphonesimulator' }
+          - { spec: cp314-ios_arm64_iphonesimulator, platform: 'iphonesimulator' }
+
+  ios:
+    needs: [python_sdist, make_ios_matrix]
+    runs-on: macos-14
+    strategy:
+      fail-fast: false
+      matrix: ${{ fromJSON(needs.make_ios_matrix.outputs.matrix_json) }}
+
+    steps:
+    - name: fetch sdist artifact
+      id: fetch_sdist
+      uses: actions/download-artifact@v4
+      with:
+        name: ${{ needs.python_sdist.outputs.sdist_artifact_name }}
+
+    - name: install python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.13'
+
+    - name: build wheel prereqs
+      run: |
+        set -eux
+        python3 -m pip install --user --upgrade cibuildwheel>=3.1.0
+        brew uninstall --ignore-dependencies libffi 2>&1 || true
+
+    - name: download libffi for iOS
+      env:
+        CFFI_IOS_LIBFFI_VERSION: '3.4.7-2'
+      run: |
+        set -eux
+
+        # Download prebuilt libffi from beeware/cpython-apple-source-deps
+        platform="${{ matrix.platform }}"
+        version="${CFFI_IOS_LIBFFI_VERSION}"
+        url="https://github.com/beeware/cpython-apple-source-deps/releases/download/libFFI-${version}/libffi-${version}-${platform}.arm64.tar.gz"
+
+        echo "Downloading libffi for iOS (${platform})..."
+        curl -L -o libffi-ios.tar.gz "${url}"
+
+        # Extract libffi
+        mkdir -p libffi-ios
+        tar zxf libffi-ios.tar.gz -C libffi-ios
+
+        # Set up paths for cibuildwheel
+        echo "LIBFFI_IOS_DIR=$(pwd)/libffi-ios" >> "$GITHUB_ENV"
+
+    - name: build/test wheels
+      id: build
+      env:
+        CIBW_BUILD: ${{ matrix.spec }}
+        CIBW_ENABLE: cpython-prerelease
+        CIBW_PLATFORM: ios
+        SDKROOT: ${{ matrix.platform }}
+        CIBW_TEST_REQUIRES: pytest setuptools
+        CIBW_TEST_SOURCES: cffi
+        # Running tests from `testing/` will not work since they try to compile C code on device
+        CIBW_TEST_COMMAND: python -m pytest -sv cffi/src/c/
+        # Environment variables for the build
+        CIBW_ENVIRONMENT: >
+          CFLAGS="-I${LIBFFI_IOS_DIR}/include"
+          LDFLAGS="-L${LIBFFI_IOS_DIR}/lib"
+          PYTHONUNBUFFERED=1
+        # Pass through our custom env vars
+        CIBW_ENVIRONMENT_PASS_IOS: LIBFFI_IOS_DIR PYTHONUNBUFFERED
+      run: |
+        set -eux
+
+        mkdir cffi
+
+        tar zxf ${{ steps.fetch_sdist.outputs.download-path }}/cffi*.tar.gz --strip-components=1 -C cffi
+
+        python3 -m cibuildwheel --output-dir dist cffi
+
+        echo "artifact_name=$(ls ./dist/)" >> "$GITHUB_OUTPUT"
+
+    - name: upload artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: ${{ steps.build.outputs.artifact_name }}
+        path: dist/*.whl
+        if-no-files-found: error
+      if: ${{ env.skip_artifact_upload != 'true' }}
+
   merge_artifacts:
-    needs: [python_sdist, linux, macos, windows]
+    needs: [python_sdist, linux, macos, windows, ios]
     runs-on: ubuntu-24.04
     steps:
     - name: merge all artifacts
@@ -451,7 +554,7 @@ jobs:
 
   check:
     if: always()
-    needs: [python_sdist, linux, macos, windows, clang_TSAN, pytest-run-parallel, merge_artifacts]
+    needs: [python_sdist, linux, macos, windows, ios, clang_TSAN, pytest-run-parallel, merge_artifacts]
     runs-on: ubuntu-24.04
     steps:
     - name: Verify all previous jobs succeeded (provides a single check to sample for gating purposes)

src/c/test_c.py

@@ -17,6 +17,9 @@
     except ImportError:
         pass
 
+is_ios = sys.platform == 'ios'
+
+
 def _setup_path():
     import os, sys
     sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
@@ -1230,6 +1233,11 @@ def test_cannot_pass_struct_with_array_of_length_0():
     BFunc2 = new_function_type((BInt,), BStruct, False)
     pytest.raises(NotImplementedError, cast(BFunc2, 123), 123)
 
+@pytest.mark.xfail(
+    is_ios,
+    reason="For an unknown reason f(1, cast(BInt, 42)) returns 36792864",
+    raises=AssertionError,
+)
 def test_call_function_9():
     BInt = new_primitive_type("int")
     BFunc9 = new_function_type((BInt,), BInt, True)    # vararg
@@ -1362,6 +1370,7 @@ def test_write_variable():
     pytest.raises(ValueError, ll.write_variable, BVoidP, "stderr", stderr)
 
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback():
     BInt = new_primitive_type("int")
     def make_callback():
@@ -1378,6 +1387,7 @@ def cb(n):
     assert str(e.value) == "'int(*)(int)' expects 1 arguments, got 0"
 
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 @pytest.mark.thread_unsafe("mocks sys.unraiseablehook")
 def test_callback_exception():
     def check_value(x):
@@ -1435,6 +1445,7 @@ def oops(*args):
         assert ff(bigvalue) == -42
 
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_return_type():
     for rettype in ["signed char", "short", "int", "long", "long long",
                     "unsigned char", "unsigned short", "unsigned int",
@@ -1455,6 +1466,7 @@ def cb(n):
         assert f(max - 1) == max
         assert f(max) == 42
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_a_lot_of_callbacks():
     BIGNUM = 10000
     if 'PY_DOT_PY' in globals(): BIGNUM = 100   # tests on py.py
@@ -1470,6 +1482,7 @@ def cb(n):
     for i, f in enumerate(flist):
         assert f(-142) == -142 + i
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_receiving_tiny_struct():
     BSChar = new_primitive_type("signed char")
     BInt = new_primitive_type("int")
@@ -1485,6 +1498,7 @@ def cb(s):
     n = f(p[0])
     assert n == -42
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_returning_tiny_struct():
     BSChar = new_primitive_type("signed char")
     BInt = new_primitive_type("int")
@@ -1502,6 +1516,7 @@ def cb(n):
     assert s.a == -10
     assert s.b == -30
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_receiving_struct():
     BSChar = new_primitive_type("signed char")
     BInt = new_primitive_type("int")
@@ -1518,6 +1533,7 @@ def cb(s):
     n = f(p[0])
     assert n == 42
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_returning_struct():
     BSChar = new_primitive_type("signed char")
     BInt = new_primitive_type("int")
@@ -1537,6 +1553,7 @@ def cb(n):
     assert s.a == -10
     assert s.b == 1E-42
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_receiving_big_struct():
     BInt = new_primitive_type("int")
     BStruct = new_struct_type("struct foo")
@@ -1561,6 +1578,7 @@ def cb(s):
     n = f(p[0])
     assert n == 42
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_returning_big_struct():
     BInt = new_primitive_type("int")
     BStruct = new_struct_type("struct foo")
@@ -1586,6 +1604,7 @@ def cb():
     for i, name in enumerate("abcdefghij"):
         assert getattr(s, name) == 13 - i
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_returning_void():
     BVoid = new_void_type()
     BFunc = new_function_type((), BVoid, False)
@@ -1694,6 +1713,7 @@ def test_enum_overflow():
                     pytest.raises(OverflowError, new_enum_type,
                                    "foo", ("AA",), (testcase,), BPrimitive)
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_returning_enum():
     BInt = new_primitive_type("int")
     BEnum = new_enum_type("foo", ('def', 'c', 'ab'), (0, 1, -20), BInt)
@@ -1710,6 +1730,7 @@ def cb(n):
     assert f(20) == 20
     assert f(21) == 21
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_returning_enum_unsigned():
     BInt = new_primitive_type("int")
     BUInt = new_primitive_type("unsigned int")
@@ -1727,6 +1748,7 @@ def cb(n):
     assert f(20) == 20
     assert f(21) == 21
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_returning_char():
     BInt = new_primitive_type("int")
     BChar = new_primitive_type("char")
@@ -1741,6 +1763,7 @@ def _hacked_pypy_uni4():
     pyuni4 = {1: True, 2: False}[len(u+'\U00012345')]
     return 'PY_DOT_PY' in globals() and not pyuni4
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_callback_returning_wchar_t():
     BInt = new_primitive_type("int")
     BWChar = new_primitive_type("wchar_t")
@@ -2310,6 +2333,8 @@ def _test_wchar_variant(typename):
     assert str(q) == repr(q)
     pytest.raises(RuntimeError, string, q)
     #
+    if is_ios:
+        return  # cannot allocate executable memory for the callback() below
     def cb(p):
         assert repr(p).startswith("<cdata '%s *' 0x" % typename)
         return len(string(p))
@@ -2546,6 +2571,7 @@ def test_errno():
     f(); f()
     assert get_errno() == 95
 
+@pytest.mark.skipif(is_ios, reason="Cannot allocate executable memory on iOS")
 def test_errno_callback():
     if globals().get('PY_DOT_PY'):
         pytest.skip("cannot run this test on py.py (e.g. fails on Windows)")
@@ -2996,6 +3022,11 @@ def test_string_assignment_to_byte_array():
     except ImportError:
         pass   # win32
 
+@pytest.mark.skipif(
+    is_ios,
+    reason="For an unknown reason fscanf() doesn't read anything on 3.14"
+           " and crashes on 3.13 (that's why it's not an xfail)",
+)
 def test_FILE():
     if sys.platform == "win32":
         pytest.skip("testing FILE not implemented")