Fixed #667: CoreKiwix for iOS Simulator

When we introduced CoreKiwix.xcframework, we made two mistakes:

- We forgot that some devs are on Apple Silicon and did not include arm64 arch for simulator
- We kept the `x86_64-apple-ios` target thinking simulator is a “just” an iOS on x64

This target mistake prevented XCode from finding our lib usable with the Simulator on x64.
Not including an arm64 version obviously prevented Silicon-using devs from using the Simulator.

The included libs changes now from

| Name                         | Content                                               |
| ---------------------------- | ----------------------------------------------------- |
| `ios-arm64`                  | All iOS devices are arm64                             |
| `ios-x86_64-simulator`       | Single x64 binary for Simulator                       |
| `macos-arm64_x86_64`         | Fat binary for macOS with both x64 and arm64          |

To

| Name                         | Content                                               |
| ---------------------------- | ----------------------------------------------------- |
| `ios-arm64`                  | All iOS devices are arm64                             |
| `ios-arm64_x86_64-simulator` | Fsat binary for iOS Simulator with both x64 and arm64 |
| `macos-arm64_x86_64`         | Fat binary for macOS with both x64 and arm64          |

- `iOSx64` Platforn renamed to `iOSx64Simulator` with its target fixed to `x86-apple-ios-simulator` (was `x86_64-apple-ios`)
- Added platformn `iOSArm64Simulator` for Apple Silicon devs to run Simulator
- `AppleXCFramework` dependency gets two changes:
    - Depends on all those platforms
    - `_make_macos_fat()` turned generic and called both for macOS fat binary and iOS Simulator one

kiwixbuild/dependencies/apple_xcframework.py

@@ -9,7 +9,13 @@ from .base import Dependency, NoopSource, Builder as BaseBuilder
 
 class AppleXCFramework(Dependency):
     name = "apple_xcframework"
-    subPlatformNames = ["macOS_x86_64", "macOS_arm64_static", "iOS_x86_64", "iOS_arm64"]
+    subPlatformNames = [
+        "macOS_x86_64",
+        "macOS_arm64_static",
+        "iOS_arm64",
+        "iOSSimulator_x86_64",
+        "iOSSimulator_arm64",
+    ]
     Source = NoopSource
 
     class Builder(BaseBuilder):
@@ -23,10 +29,18 @@ class AppleXCFramework(Dependency):
                 target for target in self.all_subplatforms if target.startswith("macOS")
             ]
 
+        @property
+        def iossimulator_subplatforms(self):
+            return [
+                target
+                for target in self.all_subplatforms
+                if target.startswith("iOSSimulator")
+            ]
+
         @property
         def ios_subplatforms(self):
             return [
-                target for target in self.all_subplatforms if target.startswith("iOS")
+                target for target in self.all_subplatforms if target.startswith("iOS_")
             ]
 
         @classmethod
@@ -56,13 +70,6 @@ class AppleXCFramework(Dependency):
                 static_ars = [str(f) for f in Path(lib_dir).glob("*.a")]
 
                 # create merged.a from all *.a in install_dir/lib
-                command = [
-                    "libtool",
-                    "-static",
-                    "-o",
-                    "merged.a",
-                    *static_ars
-                ]
                 run_command(command, lib_dir, context)
 
                 # will be included in xcframework
@@ -71,14 +78,14 @@ class AppleXCFramework(Dependency):
 
             return xcf_libs
 
-        def _make_macos_fat(self, context):
+        def make_fat_with(self, platforms, folder_name, context):
-            """create fat merged.a in fake macOS_fat install/lib with macOS archs"""
+            """create fat merged.a in {folder_name} install/lib with {platforms} archs"""
-            macos_libs = []
+            libs = []
-            for target in self.macos_subplatforms:
+            for target in platforms:
                 plt = PlatformInfo.get_platform(target)
-                macos_libs.append(pj(plt.buildEnv.install_dir, "lib", "merged.a"))
+                libs.append(pj(plt.buildEnv.install_dir, "lib", "merged.a"))
 
-            fat_dir = pj(self.buildEnv.build_dir, "macOS_fat")
+            fat_dir = pj(self.buildEnv.build_dir, folder_name)
             os.makedirs(fat_dir, exist_ok=True)
 
             output_merged = pj(fat_dir, "merged.a")
@@ -87,7 +94,7 @@ class AppleXCFramework(Dependency):
                 "-create",
                 "-output",
                 output_merged,
-                *macos_libs
+                *libs
             ]
             run_command(command, self.buildEnv.build_dir, context)
 
@@ -109,5 +116,16 @@ class AppleXCFramework(Dependency):
             xcf_libs = []
             self.command("remove_if_exists", self._remove_if_exists)
             xcf_libs += self.command("merge_libs", self._merge_libs)
-            xcf_libs += self.command("make_macos_fat", self._make_macos_fat)
+            xcf_libs += self.command(
+                "make_macos_fat",
+                self.make_fat_with,
+                self.macos_subplatforms,
+                "macOS_fat",
+            )
+            xcf_libs += self.command(
+                "make_simulator_fat",
+                self.make_fat_with,
+                self.iossimulator_subplatforms,
+                "iOS-simulator_fat",
+            )
             self.command("build_xcframework", self._build_xcframework, xcf_libs)

kiwixbuild/platforms/ios.py

@@ -131,11 +131,20 @@ class iOSArm64(ApplePlatformInfo):
     min_iphoneos_version = '15.0'
 
 
-class iOSx64(ApplePlatformInfo):
+class iOSx64Simulator(ApplePlatformInfo):
-    name = 'iOS_x86_64'
+    name = 'iOSSimulator_x86_64'
     arch = cpu = 'x86_64'
     host = 'x86_64-apple-darwin'
-    target = 'x86_64-apple-ios'
+    target = 'x86-apple-ios-simulator'
+    sdk_name = 'iphonesimulator'
+    min_iphoneos_version = '15.0'
+
+
+class iOSArm64Simulator(ApplePlatformInfo):
+    name = 'iOSSimulator_arm64'
+    arch = cpu = 'arm64'
+    host = 'arm-apple-darwin'
+    target = 'aarch64-apple-ios-simulator'
     sdk_name = 'iphonesimulator'
     min_iphoneos_version = '15.0'