[lldb] Revive TestSimulatorPlatform.py (#142244)

This test was incorrectly disabled and bitrotted since then. This PR
fixes up the test and re-enables it.

 - Build against the system libc++ (which can target the simulator)
 - Bump the deployment target for iOS and tvOS on Apple Silicon
 - Skip backdeploying to pre-Apple Silicon OS on Apple Silicon.

lldb/packages/Python/lldbsuite/test/decorators.py

@@ -9,6 +9,7 @@ import re
 import sys
 import tempfile
 import subprocess
+import json
 
 # Third-party modules
 import unittest
@@ -451,24 +452,67 @@ def apple_simulator_test(platform):
     """
     Decorate the test as a test requiring a simulator for a specific platform.
 
-    Consider that a simulator is available if you have the corresponding SDK installed.
-    The SDK identifiers for simulators are iphonesimulator, appletvsimulator, watchsimulator
+    Consider that a simulator is available if you have the corresponding SDK
+    and runtime installed.
+
+    The SDK identifiers for simulators are iphonesimulator, appletvsimulator,
+    watchsimulator
     """
 
     def should_skip_simulator_test():
         if lldbplatformutil.getHostPlatform() not in ["darwin", "macosx"]:
             return "simulator tests are run only on darwin hosts."
+
+        # Make sure we recognize the platform.
+        mapping = {
+            "iphone": "ios",
+            "appletv": "tvos",
+            "watch": "watchos",
+        }
+        if platform not in mapping:
+            return "unknown simulator platform: {}".format(platform)
+
+        # Make sure we have an SDK.
         try:
             output = subprocess.check_output(
                 ["xcodebuild", "-showsdks"], stderr=subprocess.DEVNULL
             ).decode("utf-8")
-            if re.search("%ssimulator" % platform, output):
-                return None
-            else:
+            if not re.search("%ssimulator" % platform, output):
                 return "%s simulator is not supported on this system." % platform
         except subprocess.CalledProcessError:
             return "Simulators are unsupported on this system (xcodebuild failed)"
 
+        # Make sure we a simulator runtime.
+        try:
+            sim_devices_str = subprocess.check_output(
+                ["xcrun", "simctl", "list", "-j", "devices"]
+            ).decode("utf-8")
+
+            sim_devices = json.loads(sim_devices_str)["devices"]
+            for simulator in sim_devices:
+                if isinstance(simulator, dict):
+                    runtime = simulator["name"]
+                    devices = simulator["devices"]
+                else:
+                    runtime = simulator
+                    devices = sim_devices[simulator]
+
+                if not mapping[platform] in runtime.lower():
+                    continue
+
+                for device in devices:
+                    if (
+                        "availability" in device
+                        and device["availability"] == "(available)"
+                    ):
+                        return None
+                    if "isAvailable" in device and device["isAvailable"]:
+                        return None
+
+            return "{} simulator is not supported on this system.".format(platform)
+        except (subprocess.CalledProcessError, json.decoder.JSONDecodeError):
+            return "Simulators are unsupported on this system (simctl failed)"
+
     return skipTestIfFn(should_skip_simulator_test)
 
 

lldb/test/API/macosx/simulator/TestSimulatorPlatform.py

@@ -39,15 +39,15 @@ class TestSimulatorPlatformLaunching(TestBase):
         if expected_version:
             self.assertEqual(aout_info["min_version_os_sdk"], expected_version)
 
-    @skipIf(bugnumber="rdar://76995109")
     def run_with(self, arch, os, vers, env, expected_load_command):
         env_list = [env] if env else []
         triple = "-".join([arch, "apple", os + vers] + env_list)
         sdk = lldbutil.get_xcode_sdk(os, env)
 
-        version_min = ""
         if not vers:
             vers = lldbutil.get_xcode_sdk_version(sdk)
+
+        version_min = ""
         if env == "simulator":
             version_min = "-m{}-simulator-version-min={}".format(os, vers)
         elif os == "macosx":
@@ -56,11 +56,14 @@ class TestSimulatorPlatformLaunching(TestBase):
         sdk_root = lldbutil.get_xcode_sdk_root(sdk)
         clang = lldbutil.get_xcode_clang(sdk)
 
+        print(triple)
+
         self.build(
             dictionary={
                 "ARCH": arch,
                 "ARCH_CFLAGS": "-target {} {}".format(triple, version_min),
                 "SDKROOT": sdk_root,
+                "USE_SYSTEM_STDLIB": 1,
             },
             compiler=clang,
         )
@@ -146,6 +149,7 @@ class TestSimulatorPlatformLaunching(TestBase):
 
     @skipUnlessDarwin
     @skipIfDarwinEmbedded
+    @skipIf(archs=["arm64", "arm64e"])
     def test_lc_version_min_macosx(self):
         """Test running a back-deploying non-simulator MacOS X binary"""
         self.run_with(
@@ -198,7 +202,7 @@ class TestSimulatorPlatformLaunching(TestBase):
         self.run_with(
             arch=self.getArchitecture(),
             os="ios",
-            vers="11.0",
+            vers="14.0",
             env="simulator",
             expected_load_command="LC_BUILD_VERSION",
         )
@@ -229,7 +233,7 @@ class TestSimulatorPlatformLaunching(TestBase):
         self.run_with(
             arch=self.getArchitecture(),
             os="tvos",
-            vers="11.0",
+            vers="14.0",
             env="simulator",
             expected_load_command="LC_BUILD_VERSION",
         )