Fix SDK selection using "platform select" when --sysroot/--version/--build options were specified

[ki.stfu]

Summary

This patch fixes SDK selection in the following case:

platform select remote-ios --sysroot "/Users/IliaK/Library/Developer/Xcode/iOS DeviceSupport/8.1.2 (12B440)" --build 12B440 --version 8.1.2
target create --arch arm64 "~/Project1.app"

Currently the lldb selects a first SDK version (in name order) in directory and then updates it after the device is connected. This approach ignores user's arguments and actually "platform select" command doesn't make sense.

After this patch, lldb takes a SDK which matches to user's arguments.

[clayborg]

See my inline comments and let me know

source/Plugins/Platform/MacOSX/PlatformRemoteiOS.cpp

756–777

Is this code even needed if PlatformRemoteiOS::UpdateSDKDirectoryInfosIfNeeded() puts the m_sdk_sysroot in first in the list? Or is this code for when no sysroot is specified and only a build number was specified?

[ki.stfu]

source/Plugins/Platform/MacOSX/PlatformRemoteiOS.cpp

756–777

Yes. The second case is right.

[clayborg]

Looks good then.

source/Plugins/Platform/MacOSX/PlatformRemoteiOS.h

protected:
 
     uint32_t
     FindFileInAllSDKs (const lldb_private::FileSpec &platform_file,
                        lldb_private::FileSpecList &file_list);
 
     uint32_t
     GetConnectedSDKIndex ();
 
+    // Get index of SDK in SDKDirectoryInfoCollection by its pointer and return UINT32_MAX if that SDK not found.
+    uint32_t
+    GetSDKIndexBySDKDirectoryInfo (const SDKDirectoryInfo *sdk_info);
+
 private:
     DISALLOW_COPY_AND_ASSIGN (PlatformRemoteiOS);
 
 };
 
 #endif  // liblldb_PlatformRemoteiOS_h_

source/Plugins/Platform/MacOSX/PlatformRemoteiOS.cpp

PlatformRemoteiOS::GetContainedFilesIntoVectorOfStringsCallback (void *baton,
     return FileSpec::eEnumerateDirectoryResultNext;
 }
 
 bool
 PlatformRemoteiOS::UpdateSDKDirectoryInfosIfNeeded()
 {
     if (m_sdk_directory_infos.empty())
     {
+        // A --sysroot option was supplied - add it to our list of SDKs to check
+        if (m_sdk_sysroot)
+        {
+            FileSpec sdk_sysroot_fspec(m_sdk_sysroot.GetCString(), true);
+            const SDKDirectoryInfo sdk_sysroot_directory_info(sdk_sysroot_fspec);
+            m_sdk_directory_infos.push_back(sdk_sysroot_directory_info);
+            return true;
+        }
         const char *device_support_dir = GetDeviceSupportDirectory();
         if (device_support_dir)
         {
             const bool find_directories = true;
             const bool find_files = false;
             const bool find_other = false;
 
             SDKDirectoryInfoCollection builtin_sdk_directory_infos;
if (platform_file.GetPath(platform_file_path, sizeof(platform_file_path)))
                 if (module_sp)
                 {
                     error.Clear();
                     return error;
                 }
             }
         }
         
-        // First try for an exact match of major, minor and update
+        // First try for an exact match of major, minor and update:
+        // If a particalar SDK version was specified via --version or --build, look for a match on disk.
+        const SDKDirectoryInfo *current_sdk_info = GetSDKDirectoryForCurrentOSVersion();
+        const uint32_t current_sdk_idx = GetSDKIndexBySDKDirectoryInfo(current_sdk_info);
+        if (current_sdk_idx < num_sdk_infos && current_sdk_idx != m_last_module_sdk_idx)
+        {
+            if (GetFileInSDK (platform_file_path, current_sdk_idx, platform_module_spec.GetFileSpec()))
+            {
+                module_sp.reset();
+                error = ResolveExecutable (platform_module_spec,
+                                           module_sp,
+                                           NULL);
+                if (module_sp)
+                {
+                    m_last_module_sdk_idx = current_sdk_idx;
+                    error.Clear();
+                    return error;
+                }
+            }
+        }
+
+        // Second try all SDKs that were found.
         for (uint32_t sdk_idx=0; sdk_idx<num_sdk_infos; ++sdk_idx)
         {
             if (m_last_module_sdk_idx == sdk_idx)
             {
                 // Skip the last module SDK index if we already searched
                 // it above
                 continue;
             }
PlatformRemoteiOS::GetConnectedSDKIndex ()
     }
     else
     {
         m_connected_module_sdk_idx = UINT32_MAX;
     }
     return m_connected_module_sdk_idx;
 }
 
+uint32_t
+PlatformRemoteiOS::GetSDKIndexBySDKDirectoryInfo (const SDKDirectoryInfo *sdk_info)
+{
+    if (sdk_info == NULL)
+    {
+        return UINT32_MAX;
+    }
+
+    return sdk_info - &m_sdk_directory_infos[0];
+}