Add support for building iOS wheels.

README.md

@@ -58,12 +58,12 @@ Usage
 |                 | Linux | macOS | Windows | Linux ARM | macOS ARM | Windows ARM | iOS |
 |-----------------|-------|-------|---------|-----------|-----------|-------------|-----|
 | GitHub Actions  | ✅    | ✅    | ✅       | ✅        | ✅        | ✅²         | ✅³  |
-| Azure Pipelines | ✅    | ✅    | ✅       |           | ✅        | ✅²         |     |
+| Azure Pipelines | ✅    | ✅    | ✅       |           | ✅        | ✅²         | ✅³  |
 | Travis CI       | ✅    |       | ✅      | ✅        |           |             |     |
-| AppVeyor        | ✅    | ✅    | ✅      |           | ✅        | ✅²         |     |
-| CircleCI        | ✅    | ✅    |         | ✅        | ✅        |             |     |
-| Gitlab CI       | ✅    | ✅    | ✅      | ✅¹       | ✅        |             |     |
-| Cirrus CI       | ✅    | ✅    | ✅      | ✅        | ✅        |             |     |
+| AppVeyor        | ✅    | ✅    | ✅      |           | ✅        | ✅²         | ✅³  |
+| CircleCI        | ✅    | ✅    |         | ✅        | ✅        |             | ✅³  |
+| Gitlab CI       | ✅    | ✅    | ✅      | ✅¹       | ✅        |             | ✅³  |
+| Cirrus CI       | ✅    | ✅    | ✅      | ✅        | ✅        |             | ✅³  |
 
 <sup>¹ [Requires emulation](https://cibuildwheel.pypa.io/en/stable/faq/#emulation), distributed separately. Other services may also support Linux ARM through emulation or third-party build hosts, but these are not tested in our CI.</sup><br>
 <sup>² [Uses cross-compilation](https://cibuildwheel.pypa.io/en/stable/faq/#windows-arm64). It is not possible to test `arm64` on this CI platform.</sup><br>

bin/update_pythons.py

@@ -44,13 +44,13 @@ class ConfigWinPP(TypedDict):
     url: str
 
 
-class ConfigMacOS(TypedDict):
+class ConfigApple(TypedDict):
     identifier: str
     version: str
     url: str
 
 
-AnyConfig = ConfigWinCP | ConfigWinPP | ConfigMacOS
+AnyConfig = ConfigWinCP | ConfigWinPP | ConfigApple
 
 
 # The following set of "Versions" classes allow the initial call to the APIs to
@@ -154,7 +154,7 @@ def update_version_windows(self, spec: Specifier) -> ConfigWinCP:
             url=url,
         )
 
-    def update_version_macos(self, spec: Specifier) -> ConfigMacOS:
+    def update_version_macos(self, spec: Specifier) -> ConfigApple:
         if self.arch not in {"64", "ARM64"}:
             msg = f"'{self.arch}' arch not supported yet on macOS"
             raise RuntimeError(msg)
@@ -178,7 +178,7 @@ def update_version_macos(self, spec: Specifier) -> ConfigMacOS:
             if "" in rf["platform"] == "darwin" and rf["arch"] == arch
         )
 
-        return ConfigMacOS(
+        return ConfigApple(
             identifier=identifier,
             version=f"{version.major}.{version.minor}",
             url=url,
@@ -204,7 +204,7 @@ def __init__(self) -> None:
 
     def update_version_macos(
         self, identifier: str, version: Version, spec: Specifier
-    ) -> ConfigMacOS | None:
+    ) -> ConfigApple | None:
         # see note above on Specifier.filter
         unsorted_versions = spec.filter(self.versions_dict)
         sorted_versions = sorted(unsorted_versions, reverse=True)
@@ -223,7 +223,7 @@ def update_version_macos(
 
             urls = [rf["url"] for rf in file_info if file_ident in rf["url"]]
             if urls:
-                return ConfigMacOS(
+                return ConfigApple(
                     identifier=identifier,
                     version=f"{new_version.major}.{new_version.minor}",
                     url=urls[0],
@@ -232,6 +232,48 @@ def update_version_macos(
         return None
 
 
+class CPythonIOSVersions:
+    def __init__(self) -> None:
+        response = requests.get(
+            "https://api.github.com/repos/beeware/Python-Apple-support/releases",
+            headers={
+                "Accept": "application/vnd.github+json",
+                "X-Github-Api-Version": "2022-11-28",
+            },
+        )
+        response.raise_for_status()
+
+        releases_info = response.json()
+        self.versions_dict: dict[Version, dict[int, str]] = {}
+
+        # Each release has a name like "3.13-b4"
+        for release in releases_info:
+            py_version, build = release["name"].split("-")
+            version = Version(py_version)
+            self.versions_dict.setdefault(version, {})
+
+            # There are several release assets associated with each release;
+            # The name of the asset will be something like
+            # "Python-3.11-iOS-support.b4.tar.gz". Store all builds that are
+            # "-iOS-support" builds, retaining the download URL.
+            for asset in release["assets"]:
+                filename, build, _, _ = asset["name"].rsplit(".", 3)
+                if filename.endswith("-iOS-support"):
+                    self.versions_dict[version][int(build[1:])] = asset["browser_download_url"]
+
+    def update_version_ios(self, identifier: str, version: Version) -> ConfigApple | None:
+        # Return a config using the highest build number for the given version.
+        urls = [url for _, url in sorted(self.versions_dict.get(version, {}).items())]
+        if urls:
+            return ConfigApple(
+                identifier=identifier,
+                version=str(version),
+                url=urls[-1],
+            )
+
+        return None
+
+
 # This is a universal interface to all the above Versions classes. Given an
 # identifier, it updates a config dict.
 
@@ -250,6 +292,8 @@ def __init__(self) -> None:
         self.macos_pypy = PyPyVersions("64")
         self.macos_pypy_arm64 = PyPyVersions("ARM64")
 
+        self.ios_cpython = CPythonIOSVersions()
+
     def update_config(self, config: MutableMapping[str, str]) -> None:
         identifier = config["identifier"]
         version = Version(config["version"])
@@ -282,6 +326,8 @@ def update_config(self, config: MutableMapping[str, str]) -> None:
             config_update = self.windows_t_arm64.update_version_windows(spec)
         elif "win_arm64" in identifier and identifier.startswith("cp"):
             config_update = self.windows_arm64.update_version_windows(spec)
+        elif "ios" in identifier:
+            config_update = self.ios_cpython.update_version_ios(identifier, version)
 
         assert config_update is not None, f"{identifier} not found!"
         config.update(**config_update)
@@ -317,6 +363,9 @@ def update_pythons(force: bool, level: str) -> None:
     for config in configs["macos"]["python_configurations"]:
         all_versions.update_config(config)
 
+    for config in configs["ios"]["python_configurations"]:
+        all_versions.update_config(config)
+
     result_toml = dump_python_configurations(configs)
 
     rich.print()  # spacer

cibuildwheel/architecture.py

@@ -66,9 +66,9 @@ class Architecture(StrEnum):
 
     # iOS "multiarch" architectures that include both
     # the CPU architecture and the ABI.
-    arm64_device = "arm64-iphoneos"
-    arm64_simulator = "arm64-iphonesimulator"
-    x86_64_simulator = "x86_64-iphonesimulator"
+    arm64_iphoneos = auto()
+    arm64_iphonesimulator = auto()
+    x86_64_iphonesimulator = auto()
 
     @staticmethod
     def parse_config(config: str, platform: PlatformName) -> "set[Architecture]":
@@ -113,9 +113,9 @@ def native_arch(platform: PlatformName) -> "Architecture | None":
             # simulator for the macOS native platform.
             if host_platform == "macos":
                 if native_architecture == Architecture.x86_64:
-                    return Architecture.x86_64_simulator
+                    return Architecture.x86_64_iphonesimulator
                 else:
-                    return Architecture.arm64_simulator
+                    return Architecture.arm64_iphonesimulator
             else:
                 return None
 
@@ -152,12 +152,17 @@ def auto_archs(platform: PlatformName) -> "set[Architecture]":
             result.add(Architecture.x86)
 
         elif platform == "ios":
-            # iOS defaults to building all architectures
-            result = {
-                Architecture.x86_64_simulator,
-                Architecture.arm64_simulator,
-                Architecture.arm64_device,
-            }
+            # iOS defaults to building all targets with the same CPU architecture
+            # as the native simulator architecture
+            if native_arch == Architecture.x86_64_iphonesimulator:
+                result = {
+                    Architecture.x86_64_iphonesimulator,
+                }
+            else:
+                result = {
+                    Architecture.arm64_iphonesimulator,
+                    Architecture.arm64_iphoneos,
+                }
 
         return result
 
@@ -176,9 +181,9 @@ def all_archs(platform: PlatformName) -> "set[Architecture]":
             "windows": {Architecture.x86, Architecture.AMD64, Architecture.ARM64},
             "pyodide": {Architecture.wasm32},
             "ios": {
-                Architecture.x86_64_simulator,
-                Architecture.arm64_simulator,
-                Architecture.arm64_device,
+                Architecture.x86_64_iphonesimulator,
+                Architecture.arm64_iphonesimulator,
+                Architecture.arm64_iphoneos,
             },
         }
         return all_archs_map[platform]