feat: add armv7l in auto_archs when running on aarch64

This depends on aarch32 EL0 support and thus is done conditionally.

cibuildwheel/architecture.py

@@ -3,6 +3,8 @@
 import functools
 import platform as platform_module
 import re
+import shutil
+import subprocess
 import sys
 from collections.abc import Set
 from enum import Enum
@@ -24,6 +26,19 @@
 ]
 
 
+def _check_aarch32_el0() -> bool:
+    """Check if running armv7l natively on aarch64 is supported"""
+    if not sys.platform.startswith("linux"):
+        return False
+    if platform_module.machine() != "aarch64":
+        return False
+    executable = shutil.which("linux32")
+    if executable is None:
+        return False
+    check = subprocess.run([executable, "uname", "-m"], check=False, capture_output=True, text=True)
+    return check.returncode == 0 and check.stdout.startswith("armv")
+
+
 @functools.total_ordering
 class Architecture(Enum):
     value: str
@@ -114,9 +129,12 @@ def auto_archs(platform: PlatformName) -> set[Architecture]:
             return set()  # can't build anything on this platform
         result = {native_arch}
 
-        if platform == "linux" and Architecture.x86_64 in result:
-            # x86_64 machines can run i686 containers
-            result.add(Architecture.i686)
+        if platform == "linux":
+            if Architecture.x86_64 in result:
+                # x86_64 machines can run i686 containers
+                result.add(Architecture.i686)
+            elif Architecture.aarch64 in result and _check_aarch32_el0():
+                result.add(Architecture.armv7l)
 
         if platform == "windows" and Architecture.AMD64 in result:
             result.add(Architecture.x86)

examples/github-with-qemu.yml

@@ -26,10 +26,7 @@ jobs:
           # configure cibuildwheel on Linux to build native archs ('auto'),
           # and to split the remaining architectures between the x86_64 and
           # ARM runners
-          # armv7l can be built without QEMU on GitHub Actions ARM runners but that's
-          # not the case on all ARM64 hardware hence 'auto armv7l' for native archs
-          # on the GHA ARM64 runner
-          CIBW_ARCHS_LINUX: ${{ runner.arch == 'X64' && 'auto ppc64le s390x' || 'auto armv7l' }}
+          CIBW_ARCHS_LINUX: ${{ runner.arch == 'X64' && 'auto ppc64le s390x' || 'auto' }}
 
       - uses: actions/upload-artifact@v4
         with:

test/test_manylinuxXXXX_only.py

@@ -108,6 +108,9 @@ def test(manylinux_image, tmp_path):
     if manylinux_image in {"manylinux_2_28", "manylinux_2_34"} and platform.machine() == "x86_64":
         # We don't have a manylinux_2_28+ image for i686
         add_env["CIBW_ARCHS"] = "x86_64"
+    if platform.machine() == "aarch64":
+        # We just have a manylinux_2_31 image for armv7l
+        add_env["CIBW_ARCHS"] = "aarch64"
 
     actual_wheels = utils.cibuildwheel_run(project_dir, add_env=add_env)
 
@@ -150,4 +153,8 @@ def test(manylinux_image, tmp_path):
         # We don't have a manylinux_2_28+ image for i686
         expected_wheels = [w for w in expected_wheels if "i686" not in w]
 
+    if platform.machine() == "aarch64":
+        # We just have a manylinux_2_31 image for armv7l
+        expected_wheels = [w for w in expected_wheels if "armv7l" not in w]
+
     assert set(actual_wheels) == set(expected_wheels)

test/test_musllinux_X_Y_only.py

@@ -38,7 +38,7 @@ def test(musllinux_image, tmp_path):
 
     # build the wheels
     add_env = {
-        "CIBW_SKIP": "*-manylinux*",
+        "CIBW_SKIP": "*-manylinux* *_armv7l",
         "CIBW_MUSLLINUX_X86_64_IMAGE": musllinux_image,
         "CIBW_MUSLLINUX_I686_IMAGE": musllinux_image,
         "CIBW_MUSLLINUX_AARCH64_IMAGE": musllinux_image,
@@ -54,4 +54,5 @@ def test(musllinux_image, tmp_path):
         musllinux_versions=[musllinux_image],
         single_python=True,
     )
+    expected_wheels = [w for w in expected_wheels if "armv7l" not in w]
     assert set(actual_wheels) == set(expected_wheels)

test/test_testing.py

@@ -68,7 +68,7 @@ def test_uname(self):
         # See #336 for more info.
         bits = struct.calcsize("P") * 8
         if bits == 32:
-            self.assertIn(platform.machine(), ["i686", "wasm32"])
+            self.assertIn(platform.machine(), ["i686", "armv7l","armv8l", "wasm32"])
 '''
 
 

test/utils.py

@@ -173,7 +173,7 @@ def expected_wheels(
             machine_arch = "aarch64"
 
     if manylinux_versions is None:
-        if machine_arch == "armv7l":
+        if machine_arch in ("armv7l", "aarch64"):
             manylinux_versions = ["manylinux_2_17", "manylinux2014", "manylinux_2_31"]
         elif machine_arch == "x86_64":
             manylinux_versions = [
@@ -250,14 +250,23 @@ def expected_wheels(
         if platform == "linux":
             architectures = [arch_name_for_linux(machine_arch)]
 
-            if machine_arch == "x86_64" and not single_arch:
-                architectures.append("i686")
+            if not single_arch:
+                if machine_arch == "x86_64":
+                    architectures.append("i686")
+                elif (
+                    machine_arch == "aarch64"
+                    and sys.platform.startswith("linux")
+                    and not python_abi_tag.startswith("pp")
+                ):
+                    # we assume all CI providers are able to run aarch32 EL0 on aarch64
+                    architectures.append("armv7l")
 
             if len(manylinux_versions) > 0:
                 platform_tags = [
                     ".".join(
                         f"{manylinux_version}_{architecture}"
                         for manylinux_version in manylinux_versions
+                        if (manylinux_version, architecture) != ("manylinux_2_31", "aarch64")
                     )
                     for architecture in architectures
                 ]

unit_test/architecture_test.py

@@ -1,10 +1,12 @@
 from __future__ import annotations
 
 import platform as platform_module
+import shutil
 import sys
 
 import pytest
 
+import cibuildwheel.architecture
 from cibuildwheel.architecture import Architecture
 
 
@@ -24,6 +26,7 @@ def platform_machine(request, monkeypatch):
     platform_name, platform_value, machine_value, machine_name = request.param
     monkeypatch.setattr(sys, "platform", platform_value)
     monkeypatch.setattr(platform_module, "machine", lambda: machine_value)
+    monkeypatch.setattr(cibuildwheel.architecture, "_check_aarch32_el0", lambda: True)
     return platform_name, machine_name
 
 
@@ -34,7 +37,7 @@ def test_arch_auto(platform_machine):
     expected = {
         "32": {Architecture.i686},
         "64": {Architecture.x86_64, Architecture.i686},
-        "arm": {Architecture.aarch64},
+        "arm": {Architecture.aarch64, Architecture.armv7l},
     }
     assert arch_set == expected[machine_name]
 
@@ -71,7 +74,7 @@ def test_arch_auto32(platform_machine):
     platform_name, machine_name = platform_machine
 
     arch_set = Architecture.parse_config("auto32", "linux")
-    expected = {"32": {Architecture.i686}, "64": {Architecture.i686}, "arm": set()}
+    expected = {"32": {Architecture.i686}, "64": {Architecture.i686}, "arm": {Architecture.armv7l}}
     assert arch_set == expected[machine_name]
 
     arch_set = Architecture.parse_config("auto32", "macos")
@@ -80,3 +83,18 @@ def test_arch_auto32(platform_machine):
     arch_set = Architecture.parse_config("auto32", "windows")
     expected = {"32": {Architecture.x86}, "64": {Architecture.x86}, "arm": set()}
     assert arch_set == expected[machine_name]
+
+
+def test_arch_auto_no_aarch32(monkeypatch):
+    monkeypatch.setattr(sys, "platform", "linux")
+    monkeypatch.setattr(platform_module, "machine", lambda: "aarch64")
+    monkeypatch.setattr(shutil, "which", lambda *args, **kwargs: None)
+
+    arch_set = Architecture.parse_config("auto", "linux")
+    assert arch_set == {Architecture.aarch64}
+
+    arch_set = Architecture.parse_config("auto64", "linux")
+    assert arch_set == {Architecture.aarch64}
+
+    arch_set = Architecture.parse_config("auto32", "linux")
+    assert len(arch_set) == 0

unit_test/main_tests/conftest.py

@@ -8,7 +8,7 @@
 
 import pytest
 
-from cibuildwheel import __main__, linux, macos, pyodide, windows
+from cibuildwheel import __main__, architecture, linux, macos, pyodide, windows
 from cibuildwheel.util import file
 
 
@@ -44,8 +44,8 @@ def ignore_call(*args, **kwargs):
     monkeypatch.setattr(linux, "build", fail_on_call)
     monkeypatch.setattr(macos, "build", fail_on_call)
     monkeypatch.setattr(pyodide, "build", fail_on_call)
-
     monkeypatch.setattr(Path, "mkdir", ignore_call)
+    monkeypatch.setattr(architecture, "_check_aarch32_el0", lambda: True)
 
 
 @pytest.fixture(autouse=True)