[lldb] Read from the Rosetta shared cache with Xcode 14

[JDevlieghere]

Summary

Xcode 14 no longer puts the Rosetta expanded shared cache under 16.0. Instead, it includes the real version number (e.g. 13.0), the build string and the architecture, similar to the device support directory names for iOS, tvOS and watchOS.

Currently, when there are multiple directories, we end up picking the wrong one in GetSDKDirectoryForCurrentOSVersion. The problem is that without the build string we have no way to differentiate between directories with the same version number.

13.0 (22A111) x86_64/
13.0 (22A222) x86_64/
13.0 (22A333) x86_64/

This patch fixes the problem by using GetOSBuildString which, as the name implies, returns the build string if it's known. For the host platform this returns the host build string while for a remote platform this returns the remote build string.

I added a Rosetta test and verified that this doesn't break remote ios debugging.

rdar://97576121

[mib]

LGTM with a comment.

lldb/test/API/macosx/rosetta/TestRosetta.py

8–11

Why not add this to decorators.py ?

[aprantl]

lldb/test/API/macosx/rosetta/TestRosetta.py

8–11

FWIW, there's a skipIfRosetta decorator there already.

[JDevlieghere]

lldb/test/API/macosx/rosetta/TestRosetta.py

8–11

@adrian: That's not the same thing, that's when the test suite as a whole is run under rosetta.
@ismail: I thought it was too specific and only used for one test, but I think it makes sense to move it there.

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

def skipIfTargetAndroid(bugnumber=None, api_levels=None, archs=None):
     """
     return skipTestIfFn(
         _skip_for_android(
             "skipping for android",
             api_levels,
             archs),
         bugnumber)
 
+def skipUnlessAppleSilicon(func):
+    """Decorate the item to skip tests unless running on Apple Silicon."""
+    def not_apple_silicon(test):
+        if platform.system() != 'Darwin' or test.getArchitecture() not in [
+                'arm64', 'arm64e'
+        ]:
+            return "Test only runs on Apple Silicon"
+        return None
+
+    return skipTestIfFn(not_apple_silicon)(func)
+
 def skipUnlessSupportedTypeAttribute(attr):
     """Decorate the item to skip test unless Clang supports type __attribute__(attr)."""
     def compiler_doesnt_support_struct_attribute(self):
         compiler_path = self.getCompiler()
         f = tempfile.NamedTemporaryFile()
         cmd = [self.getCompiler(), "-x", "c++", "-c", "-o", f.name, "-"]
         p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
         stdout, stderr = p.communicate('struct __attribute__((%s)) Test {};'%attr)

lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp

bool PlatformDarwinDevice::UpdateSDKDirectoryInfosIfNeeded() {
   return !m_sdk_directory_infos.empty();
 }
 
 const PlatformDarwinDevice::SDKDirectoryInfo *
 PlatformDarwinDevice::GetSDKDirectoryForCurrentOSVersion() {
   uint32_t i;
   if (UpdateSDKDirectoryInfosIfNeeded()) {
     const uint32_t num_sdk_infos = m_sdk_directory_infos.size();
-
-    // Check to see if the user specified a build string. If they did, then be
-    // sure to match it.
     std::vector<bool> check_sdk_info(num_sdk_infos, true);
-    ConstString build(m_sdk_build);
+
+    // Prefer the user SDK build string.
+    ConstString build = GetSDKBuild();
+
+    // Fall back to the platform's build string.
+    if (!build) {
+      if (llvm::Optional<std::string> os_build_str = GetOSBuildString()) {
+        build = ConstString(*os_build_str);
+      }
+    }
+
+    // If we have a build string, only check platforms for which the build
+    // string matches.
     if (build) {
       for (i = 0; i < num_sdk_infos; ++i)
         check_sdk_info[i] = m_sdk_directory_infos[i].build == build;
     }
 
     // If we are connected we can find the version of the OS the platform us
     // running on and select the right SDK
     llvm::VersionTuple version = GetOSVersion();
     if (!version.empty()) {
       if (UpdateSDKDirectoryInfosIfNeeded()) {
-        // First try for an exact match of major, minor and update
+        // First try for an exact match of major, minor and update.
         for (i = 0; i < num_sdk_infos; ++i) {
           if (check_sdk_info[i]) {
             if (m_sdk_directory_infos[i].version == version)
               return &m_sdk_directory_infos[i];
           }
         }
-        // First try for an exact match of major and minor
+        // Try for an exact match of major and minor.
         for (i = 0; i < num_sdk_infos; ++i) {
           if (check_sdk_info[i]) {
             if (m_sdk_directory_infos[i].version.getMajor() ==
                     version.getMajor() &&
                 m_sdk_directory_infos[i].version.getMinor() ==
                     version.getMinor()) {
               return &m_sdk_directory_infos[i];
             }
           }
         }
-        // Lastly try to match of major version only..
+        // Lastly try to match of major version only.
         for (i = 0; i < num_sdk_infos; ++i) {
           if (check_sdk_info[i]) {
             if (m_sdk_directory_infos[i].version.getMajor() ==
                 version.getMajor()) {
               return &m_sdk_directory_infos[i];
             }
           }
         }
       }
     } else if (build) {
-      // No version, just a build number, search for the first one that matches
+      // No version, just a build number, return the first one that matches.
       for (i = 0; i < num_sdk_infos; ++i)
         if (check_sdk_info[i])
           return &m_sdk_directory_infos[i];
     }
   }
   return nullptr;
 }
 

lldb/test/API/macosx/rosetta/Makefile

+C_SOURCES := main.c
+override ARCH = x86_64
+
+include Makefile.rules

lldb/test/API/macosx/rosetta/TestRosetta.py

+import re
+import lldb
+import lldbsuite.test.lldbutil as lldbutil
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+
+
+def get_os_version():
+    try:
+        os_version_str = subprocess.check_output(["sysctl", "kern.osversion"
+                                                  ]).decode('utf-8')
+    except subprocess.CalledProcessError:
+        return None
+    m = re.match(r'kern\.osversion: (\w+)', os_version_str)
+    if m:
+        return m.group(1)
+    return None
+
+
+def has_rosetta_shared_cache(os_version):
+    if not os_version:
+        return False
+    macos_device_support = os.path.join(os.path.expanduser("~"), 'Library',
+                                        'Developer', 'Xcode',
+                                        'macOS DeviceSupport')
+    for _, subdirs, _ in os.walk(macos_device_support):
+        for subdir in subdirs:
+            if os_version in subdir:
+                return True
+    return False
+
+
+class TestRosetta(TestBase):
+
+    NO_DEBUG_INFO_TESTCASE = True
+
+    @skipUnlessAppleSilicon
+    def test_rosetta(self):
+        """There can be many tests in a test case - describe this test here."""
+        self.build()
+        self.main_source_file = lldb.SBFileSpec("main.c")
+
+        broadcaster = self.dbg.GetBroadcaster()
+        listener = lldbutil.start_listening_from(
+            broadcaster, lldb.SBDebugger.eBroadcastBitWarning)
+
+        target, process, thread, bkpt = lldbutil.run_to_source_breakpoint(
+            self, "Set a breakpoint here", self.main_source_file)
+
+        event = lldb.SBEvent()
+        os_version = get_os_version()
+        if not has_rosetta_shared_cache(os_version):
+            self.assertTrue(listener.GetNextEvent(event))
+        else:
+            self.assertFalse(listener.GetNextEvent(event))

lldb/test/API/macosx/rosetta/main.c

+#include <stdio.h>
+
+int main() {
+  int i = 0; // Set a breakpoint here
+  return i;
+}