Merge commit 'b618cf7a378d' from llvm.org/release/11.x into apple/stable/20200714

13 files changed, 165 insertions, 112 deletions

diff --git a/lldb/include/lldb/Core/ModuleList.h b/lldb/include/lldb/Core/ModuleList.h
index 1de9f9964ada..e7eddbd9cff1 100644
--- a/lldb/include/lldb/Core/ModuleList.h
+++ b/lldb/include/lldb/Core/ModuleList.h
@@ -443,12 +443,11 @@ public:
 
   static bool ModuleIsInCache(const Module *module_ptr);
 
-  static Status GetSharedModule(const ModuleSpec &module_spec,
-                                lldb::ModuleSP &module_sp,
-                                const FileSpecList *module_search_paths_ptr,
-                                lldb::ModuleSP *old_module_sp_ptr,
-                                bool *did_create_ptr,
-                                bool always_create = false);
+  static Status
+  GetSharedModule(const ModuleSpec &module_spec, lldb::ModuleSP &module_sp,
+                  const FileSpecList *module_search_paths_ptr,
+                  llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules,
+                  bool *did_create_ptr, bool always_create = false);
 
   static bool RemoveSharedModule(lldb::ModuleSP &module_sp);
 
diff --git a/lldb/include/lldb/Target/Platform.h b/lldb/include/lldb/Target/Platform.h
index bbecd6631739..c0fc5458a996 100644
--- a/lldb/include/lldb/Target/Platform.h
+++ b/lldb/include/lldb/Target/Platform.h
@@ -301,11 +301,10 @@ public:
   LocateExecutableScriptingResources(Target *target, Module &module,
                                      Stream *feedback_stream);
 
-  virtual Status GetSharedModule(const ModuleSpec &module_spec,
-                                 Process *process, lldb::ModuleSP &module_sp,
-                                 const FileSpecList *module_search_paths_ptr,
-                                 lldb::ModuleSP *old_module_sp_ptr,
-                                 bool *did_create_ptr);
+  virtual Status GetSharedModule(
+      const ModuleSpec &module_spec, Process *process,
+      lldb::ModuleSP &module_sp, const FileSpecList *module_search_paths_ptr,
+      llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules, bool *did_create_ptr);
 
   virtual bool GetModuleSpec(const FileSpec &module_file_spec,
                              const ArchSpec &arch, ModuleSpec &module_spec);
diff --git a/lldb/source/Core/ModuleList.cpp b/lldb/source/Core/ModuleList.cpp
index b6fec4850d75..756e36187260 100644
--- a/lldb/source/Core/ModuleList.cpp
+++ b/lldb/source/Core/ModuleList.cpp
@@ -732,11 +732,11 @@ size_t ModuleList::RemoveOrphanSharedModules(bool mandatory) {
   return GetSharedModuleList().RemoveOrphans(mandatory);
 }
 
-Status ModuleList::GetSharedModule(const ModuleSpec &module_spec,
-                                   ModuleSP &module_sp,
-                                   const FileSpecList *module_search_paths_ptr,
-                                   ModuleSP *old_module_sp_ptr,
-                                   bool *did_create_ptr, bool always_create) {
+Status
+ModuleList::GetSharedModule(const ModuleSpec &module_spec, ModuleSP &module_sp,
+                            const FileSpecList *module_search_paths_ptr,
+                            llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules,
+                            bool *did_create_ptr, bool always_create) {
   ModuleList &shared_module_list = GetSharedModuleList();
   std::lock_guard<std::recursive_mutex> guard(
       shared_module_list.m_modules_mutex);
@@ -748,8 +748,6 @@ Status ModuleList::GetSharedModule(const ModuleSpec &module_spec,
 
   if (did_create_ptr)
     *did_create_ptr = false;
-  if (old_module_sp_ptr)
-    old_module_sp_ptr->reset();
 
   const UUID *uuid_ptr = module_spec.GetUUIDPtr();
   const FileSpec &module_file_spec = module_spec.GetFileSpec();
@@ -770,8 +768,8 @@ Status ModuleList::GetSharedModule(const ModuleSpec &module_spec,
 
         // Make sure the file for the module hasn't been modified
         if (module_sp->FileHasChanged()) {
-          if (old_module_sp_ptr && !*old_module_sp_ptr)
-            *old_module_sp_ptr = module_sp;
+          if (old_modules)
+            old_modules->push_back(module_sp);
 
           Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_MODULES));
           if (log != nullptr)
@@ -925,8 +923,8 @@ Status ModuleList::GetSharedModule(const ModuleSpec &module_spec,
             located_binary_modulespec.GetFileSpec());
         if (file_spec_mod_time != llvm::sys::TimePoint<>()) {
           if (file_spec_mod_time != module_sp->GetModificationTime()) {
-            if (old_module_sp_ptr)
-              *old_module_sp_ptr = module_sp;
+            if (old_modules)
+              old_modules->push_back(module_sp);
             shared_module_list.Remove(module_sp);
             module_sp.reset();
           }
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
index d1064a0c8f3e..c893170bf41f 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
@@ -221,7 +221,7 @@ BringInRemoteFile(Platform *platform,
 lldb_private::Status PlatformDarwin::GetSharedModuleWithLocalCache(
     const lldb_private::ModuleSpec &module_spec, lldb::ModuleSP &module_sp,
     const lldb_private::FileSpecList *module_search_paths_ptr,
-    lldb::ModuleSP *old_module_sp_ptr, bool *did_create_ptr) {
+    llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules, bool *did_create_ptr) {
 
   Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM));
   LLDB_LOGF(log,
@@ -262,7 +262,7 @@ lldb_private::Status PlatformDarwin::GetSharedModuleWithLocalCache(
   }
 
   err = ModuleList::GetSharedModule(module_spec, module_sp,
-                                    module_search_paths_ptr, old_module_sp_ptr,
+                                    module_search_paths_ptr, old_modules,
                                     did_create_ptr);
   if (module_sp)
     return err;
@@ -365,8 +365,8 @@ lldb_private::Status PlatformDarwin::GetSharedModuleWithLocalCache(
 
 Status PlatformDarwin::GetSharedModule(
     const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
-    const FileSpecList *module_search_paths_ptr, ModuleSP *old_module_sp_ptr,
-    bool *did_create_ptr) {
+    const FileSpecList *module_search_paths_ptr,
+    llvm::SmallVectorImpl<ModuleSP> *old_modules, bool *did_create_ptr) {
   Status error;
   module_sp.reset();
 
@@ -375,16 +375,16 @@ Status PlatformDarwin::GetSharedModule(
     // module first.
     if (m_remote_platform_sp) {
       error = m_remote_platform_sp->GetSharedModule(
-          module_spec, process, module_sp, module_search_paths_ptr,
-          old_module_sp_ptr, did_create_ptr);
+          module_spec, process, module_sp, module_search_paths_ptr, old_modules,
+          did_create_ptr);
     }
   }
 
   if (!module_sp) {
     // Fall back to the local platform and find the file locally
     error = Platform::GetSharedModule(module_spec, process, module_sp,
-                                      module_search_paths_ptr,
-                                      old_module_sp_ptr, did_create_ptr);
+                                      module_search_paths_ptr, old_modules,
+                                      did_create_ptr);
 
     const FileSpec &platform_file = module_spec.GetFileSpec();
     if (!module_sp && module_search_paths_ptr && platform_file) {
@@ -397,7 +397,7 @@ Status PlatformDarwin::GetSharedModule(
           new_module_spec.GetFileSpec() = bundle_directory;
           if (Host::ResolveExecutableInBundle(new_module_spec.GetFileSpec())) {
             Status new_error(Platform::GetSharedModule(
-                new_module_spec, process, module_sp, nullptr, old_module_sp_ptr,
+                new_module_spec, process, module_sp, nullptr, old_modules,
                 did_create_ptr));
 
             if (module_sp)
@@ -424,8 +424,8 @@ Status PlatformDarwin::GetSharedModule(
                 ModuleSpec new_module_spec(module_spec);
                 new_module_spec.GetFileSpec() = new_file_spec;
                 Status new_error(Platform::GetSharedModule(
-                    new_module_spec, process, module_sp, nullptr,
-                    old_module_sp_ptr, did_create_ptr));
+                    new_module_spec, process, module_sp, nullptr, old_modules,
+                    did_create_ptr));
 
                 if (module_sp) {
                   module_sp->SetPlatformFileSpec(new_file_spec);
@@ -1683,8 +1683,8 @@ PlatformDarwin::LaunchProcess(lldb_private::ProcessLaunchInfo &launch_info) {
 
 lldb_private::Status PlatformDarwin::FindBundleBinaryInExecSearchPaths(
     const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
-    const FileSpecList *module_search_paths_ptr, ModuleSP *old_module_sp_ptr,
-    bool *did_create_ptr) {
+    const FileSpecList *module_search_paths_ptr,
+    llvm::SmallVectorImpl<ModuleSP> *old_modules, bool *did_create_ptr) {
   const FileSpec &platform_file = module_spec.GetFileSpec();
   // See if the file is present in any of the module_search_paths_ptr
   // directories.
@@ -1741,9 +1741,9 @@ lldb_private::Status PlatformDarwin::FindBundleBinaryInExecSearchPaths(
         if (FileSystem::Instance().Exists(path_to_try)) {
           ModuleSpec new_module_spec(module_spec);
           new_module_spec.GetFileSpec() = path_to_try;
-          Status new_error(Platform::GetSharedModule(
-              new_module_spec, process, module_sp, nullptr, old_module_sp_ptr,
-              did_create_ptr));
+          Status new_error(
+              Platform::GetSharedModule(new_module_spec, process, module_sp,
+                                        nullptr, old_modules, did_create_ptr));
 
           if (module_sp) {
             module_sp->SetPlatformFileSpec(path_to_try);
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.h b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.h
index 8e28a7000310..4e9a9495893b 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.h
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.h
@@ -46,7 +46,7 @@ public:
   GetSharedModule(const lldb_private::ModuleSpec &module_spec,
                   lldb_private::Process *process, lldb::ModuleSP &module_sp,
                   const lldb_private::FileSpecList *module_search_paths_ptr,
-                  lldb::ModuleSP *old_module_sp_ptr,
+                  llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules,
                   bool *did_create_ptr) override;
 
   size_t GetSoftwareBreakpointTrapOpcode(
@@ -132,7 +132,7 @@ protected:
   virtual lldb_private::Status GetSharedModuleWithLocalCache(
       const lldb_private::ModuleSpec &module_spec, lldb::ModuleSP &module_sp,
       const lldb_private::FileSpecList *module_search_paths_ptr,
-      lldb::ModuleSP *old_module_sp_ptr, bool *did_create_ptr);
+      llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules, bool *did_create_ptr);
 
   struct SDKEnumeratorInfo {
     lldb_private::FileSpec found_path;
@@ -158,7 +158,7 @@ protected:
       const lldb_private::ModuleSpec &module_spec,
       lldb_private::Process *process, lldb::ModuleSP &module_sp,
       const lldb_private::FileSpecList *module_search_paths_ptr,
-      lldb::ModuleSP *old_module_sp_ptr, bool *did_create_ptr);
+      llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules, bool *did_create_ptr);
 
   static std::string FindComponentInPath(llvm::StringRef path,
                                          llvm::StringRef component);
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.cpp b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.cpp
index 54f49601e811..76ce500ad784 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.cpp
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.cpp
@@ -727,8 +727,8 @@ PlatformDarwinKernel::GetDWARFBinaryInDSYMBundle(FileSpec dsym_bundle) {
 
 Status PlatformDarwinKernel::GetSharedModule(
     const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
-    const FileSpecList *module_search_paths_ptr, ModuleSP *old_module_sp_ptr,
-    bool *did_create_ptr) {
+    const FileSpecList *module_search_paths_ptr,
+    llvm::SmallVectorImpl<ModuleSP> *old_modules, bool *did_create_ptr) {
   Status error;
   module_sp.reset();
   const FileSpec &platform_file = module_spec.GetFileSpec();
@@ -740,26 +740,26 @@ Status PlatformDarwinKernel::GetSharedModule(
   if (!kext_bundle_id.empty() && module_spec.GetUUID().IsValid()) {
     if (kext_bundle_id == "mach_kernel") {
       return GetSharedModuleKernel(module_spec, process, module_sp,
-                                   module_search_paths_ptr, old_module_sp_ptr,
+                                   module_search_paths_ptr, old_modules,
                                    did_create_ptr);
     } else {
       return GetSharedModuleKext(module_spec, process, module_sp,
-                                 module_search_paths_ptr, old_module_sp_ptr,
+                                 module_search_paths_ptr, old_modules,
                                  did_create_ptr);
     }
   } else {
     // Give the generic methods, including possibly calling into  DebugSymbols
     // framework on macOS systems, a chance.
     return PlatformDarwin::GetSharedModule(module_spec, process, module_sp,
-                                           module_search_paths_ptr,
-                                           old_module_sp_ptr, did_create_ptr);
+                                           module_search_paths_ptr, old_modules,
+                                           did_create_ptr);
   }
 }
 
 Status PlatformDarwinKernel::GetSharedModuleKext(
     const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
-    const FileSpecList *module_search_paths_ptr, ModuleSP *old_module_sp_ptr,
-    bool *did_create_ptr) {
+    const FileSpecList *module_search_paths_ptr,
+    llvm::SmallVectorImpl<ModuleSP> *old_modules, bool *did_create_ptr) {
   Status error;
   module_sp.reset();
   const FileSpec &platform_file = module_spec.GetFileSpec();
@@ -785,8 +785,8 @@ Status PlatformDarwinKernel::GetSharedModuleKext(
   // Give the generic methods, including possibly calling into  DebugSymbols
   // framework on macOS systems, a chance.
   error = PlatformDarwin::GetSharedModule(module_spec, process, module_sp,
-                                          module_search_paths_ptr,
-                                          old_module_sp_ptr, did_create_ptr);
+                                          module_search_paths_ptr, old_modules,
+                                          did_create_ptr);
   if (error.Success() && module_sp.get()) {
     return error;
   }
@@ -811,8 +811,8 @@ Status PlatformDarwinKernel::GetSharedModuleKext(
 
 Status PlatformDarwinKernel::GetSharedModuleKernel(
     const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
-    const FileSpecList *module_search_paths_ptr, ModuleSP *old_module_sp_ptr,
-    bool *did_create_ptr) {
+    const FileSpecList *module_search_paths_ptr,
+    llvm::SmallVectorImpl<ModuleSP> *old_modules, bool *did_create_ptr) {
   Status error;
   module_sp.reset();
 
@@ -878,8 +878,8 @@ Status PlatformDarwinKernel::GetSharedModuleKernel(
   // Give the generic methods, including possibly calling into  DebugSymbols
   // framework on macOS systems, a chance.
   error = PlatformDarwin::GetSharedModule(module_spec, process, module_sp,
-                                          module_search_paths_ptr,
-                                          old_module_sp_ptr, did_create_ptr);
+                                          module_search_paths_ptr, old_modules,
+                                          did_create_ptr);
   if (error.Success() && module_sp.get()) {
     return error;
   }
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.h b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.h
index cd9e9d70f8ed..a32024e7b1e4 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.h
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.h
@@ -57,7 +57,7 @@ public:
   GetSharedModule(const lldb_private::ModuleSpec &module_spec,
                   lldb_private::Process *process, lldb::ModuleSP &module_sp,
                   const lldb_private::FileSpecList *module_search_paths_ptr,
-                  lldb::ModuleSP *old_module_sp_ptr,
+                  llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules,
                   bool *did_create_ptr) override;
 
   bool GetSupportedArchitectureAtIndex(uint32_t idx,
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformMacOSX.cpp b/lldb/source/Plugins/Platform/MacOSX/PlatformMacOSX.cpp
index ccf06cea2594..3e1b35c2f9ef 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformMacOSX.cpp
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformMacOSX.cpp
@@ -157,10 +157,10 @@ lldb_private::Status PlatformMacOSX::GetSharedModule(
     const lldb_private::ModuleSpec &module_spec, Process *process,
     lldb::ModuleSP &module_sp,
     const lldb_private::FileSpecList *module_search_paths_ptr,
-    lldb::ModuleSP *old_module_sp_ptr, bool *did_create_ptr) {
-  Status error = GetSharedModuleWithLocalCache(
-      module_spec, module_sp, module_search_paths_ptr, old_module_sp_ptr,
-      did_create_ptr);
+    llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules, bool *did_create_ptr) {
+  Status error = GetSharedModuleWithLocalCache(module_spec, module_sp,
+                                               module_search_paths_ptr,
+                                               old_modules, did_create_ptr);
 
   if (module_sp) {
     if (module_spec.GetArchitecture().GetCore() ==
@@ -171,15 +171,16 @@ lldb_private::Status PlatformMacOSX::GetSharedModule(
         ModuleSpec module_spec_x86_64(module_spec);
         module_spec_x86_64.GetArchitecture() = ArchSpec("x86_64-apple-macosx");
         lldb::ModuleSP x86_64_module_sp;
-        lldb::ModuleSP old_x86_64_module_sp;
+        llvm::SmallVector<lldb::ModuleSP, 1> old_x86_64_modules;
         bool did_create = false;
         Status x86_64_error = GetSharedModuleWithLocalCache(
             module_spec_x86_64, x86_64_module_sp, module_search_paths_ptr,
-            &old_x86_64_module_sp, &did_create);
+            &old_x86_64_modules, &did_create);
         if (x86_64_module_sp && x86_64_module_sp->GetObjectFile()) {
           module_sp = x86_64_module_sp;
-          if (old_module_sp_ptr)
-            *old_module_sp_ptr = old_x86_64_module_sp;
+          if (old_modules)
+            old_modules->append(old_x86_64_modules.begin(),
+                                old_x86_64_modules.end());
           if (did_create_ptr)
             *did_create_ptr = did_create;
           return x86_64_error;
@@ -189,7 +190,9 @@ lldb_private::Status PlatformMacOSX::GetSharedModule(
   }
 
   if (!module_sp) {
-      error = FindBundleBinaryInExecSearchPaths (module_spec, process, module_sp, module_search_paths_ptr, old_module_sp_ptr, did_create_ptr);
+    error = FindBundleBinaryInExecSearchPaths(module_spec, process, module_sp,
+                                              module_search_paths_ptr,
+                                              old_modules, did_create_ptr);
   }
   return error;
 }
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformMacOSX.h b/lldb/source/Plugins/Platform/MacOSX/PlatformMacOSX.h
index 70dd05407ac8..d64601f65196 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformMacOSX.h
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformMacOSX.h
@@ -40,7 +40,7 @@ public:
   GetSharedModule(const lldb_private::ModuleSpec &module_spec,
                   lldb_private::Process *process, lldb::ModuleSP &module_sp,
                   const lldb_private::FileSpecList *module_search_paths_ptr,
-                  lldb::ModuleSP *old_module_sp_ptr,
+                  llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules,
                   bool *did_create_ptr) override;
 
   const char *GetDescription() override { return GetDescriptionStatic(); }
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteDarwinDevice.cpp b/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteDarwinDevice.cpp
index 934b786a6f94..8a11f40ba0ab 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteDarwinDevice.cpp
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteDarwinDevice.cpp
@@ -499,8 +499,8 @@ Status PlatformRemoteDarwinDevice::GetSymbolFile(const FileSpec &platform_file,
 
 Status PlatformRemoteDarwinDevice::GetSharedModule(
     const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
-    const FileSpecList *module_search_paths_ptr, ModuleSP *old_module_sp_ptr,
-    bool *did_create_ptr) {
+    const FileSpecList *module_search_paths_ptr,
+    llvm::SmallVectorImpl<ModuleSP> *old_modules, bool *did_create_ptr) {
   // For iOS, the SDK files are all cached locally on the host system. So first
   // we ask for the file in the cached SDK, then we attempt to get a shared
   // module for the right architecture with the right UUID.
@@ -603,24 +603,25 @@ Status PlatformRemoteDarwinDevice::GetSharedModule(
   // This may not be an SDK-related module.  Try whether we can bring in the
   // thing to our local cache.
   error = GetSharedModuleWithLocalCache(module_spec, module_sp,
-                                        module_search_paths_ptr,
-                                        old_module_sp_ptr, did_create_ptr);
+                                        module_search_paths_ptr, old_modules,
+                                        did_create_ptr);
   if (error.Success())
     return error;
 
   // See if the file is present in any of the module_search_paths_ptr
   // directories.
   if (!module_sp)
-    error = PlatformDarwin::FindBundleBinaryInExecSearchPaths (module_spec, process, module_sp,
-            module_search_paths_ptr, old_module_sp_ptr, did_create_ptr);
+    error = PlatformDarwin::FindBundleBinaryInExecSearchPaths(
+        module_spec, process, module_sp, module_search_paths_ptr, old_modules,
+        did_create_ptr);
 
   if (error.Success())
     return error;
 
   const bool always_create = false;
-  error = ModuleList::GetSharedModule(
-      module_spec, module_sp, module_search_paths_ptr, old_module_sp_ptr,
-      did_create_ptr, always_create);
+  error = ModuleList::GetSharedModule(module_spec, module_sp,
+                                      module_search_paths_ptr, old_modules,
+                                      did_create_ptr, always_create);
 
   if (module_sp)
     module_sp->SetPlatformFileSpec(platform_file);
diff --git a/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteDarwinDevice.h b/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteDarwinDevice.h
index 8731984e1ab9..6f6ede7c34b7 100644
--- a/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteDarwinDevice.h
+++ b/lldb/source/Plugins/Platform/MacOSX/PlatformRemoteDarwinDevice.h
@@ -38,7 +38,7 @@ public:
   GetSharedModule(const lldb_private::ModuleSpec &module_spec,
                   lldb_private::Process *process, lldb::ModuleSP &module_sp,
                   const lldb_private::FileSpecList *module_search_paths_ptr,
-                  lldb::ModuleSP *old_module_sp_ptr,
+                  llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules,
                   bool *did_create_ptr) override;
 
   void
diff --git a/lldb/source/Target/Platform.cpp b/lldb/source/Target/Platform.cpp
index 7e1b7450de0e..7a90fa1b9865 100644
--- a/lldb/source/Target/Platform.cpp
+++ b/lldb/source/Target/Platform.cpp
@@ -218,15 +218,14 @@ Platform::LocateExecutableScriptingResources(Target *target, Module &module,
 //    return PlatformSP();
 //}
 
-Status Platform::GetSharedModule(const ModuleSpec &module_spec,
-                                 Process *process, ModuleSP &module_sp,
-                                 const FileSpecList *module_search_paths_ptr,
-                                 ModuleSP *old_module_sp_ptr,
-                                 bool *did_create_ptr) {
+Status Platform::GetSharedModule(
+    const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
+    const FileSpecList *module_search_paths_ptr,
+    llvm::SmallVectorImpl<lldb::ModuleSP> *old_modules, bool *did_create_ptr) {
   if (IsHost())
-    return ModuleList::GetSharedModule(
-        module_spec, module_sp, module_search_paths_ptr, old_module_sp_ptr,
-        did_create_ptr, false);
+    return ModuleList::GetSharedModule(module_spec, module_sp,
+                                       module_search_paths_ptr, old_modules,
+                                       did_create_ptr, false);
 
   // Module resolver lambda.
   auto resolver = [&](const ModuleSpec &spec) {
@@ -239,17 +238,17 @@ Status Platform::GetSharedModule(const ModuleSpec &module_spec,
       resolved_spec.GetFileSpec().PrependPathComponent(
           m_sdk_sysroot.GetStringRef());
       // Try to get shared module with resolved spec.
-      error = ModuleList::GetSharedModule(
-          resolved_spec, module_sp, module_search_paths_ptr, old_module_sp_ptr,
-          did_create_ptr, false);
+      error = ModuleList::GetSharedModule(resolved_spec, module_sp,
+                                          module_search_paths_ptr, old_modules,
+                                          did_create_ptr, false);
     }
     // If we don't have sysroot or it didn't work then
     // try original module spec.
     if (!error.Success()) {
       resolved_spec = spec;
-      error = ModuleList::GetSharedModule(
-          resolved_spec, module_sp, module_search_paths_ptr, old_module_sp_ptr,
-          did_create_ptr, false);
+      error = ModuleList::GetSharedModule(resolved_spec, module_sp,
+                                          module_search_paths_ptr, old_modules,
+                                          did_create_ptr, false);
     }
     if (error.Success() && module_sp)
       module_sp->SetPlatformFileSpec(resolved_spec.GetFileSpec());
diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index 4b55c43c35ac..fff2097403a0 100644
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -1971,8 +1971,9 @@ ModuleSP Target::GetOrCreateModule(const ModuleSpec &module_spec, bool notify,
     module_sp = m_images.FindFirstModule(module_spec);
 
   if (!module_sp) {
-    ModuleSP old_module_sp; // This will get filled in if we have a new version
-                            // of the library
+    llvm::SmallVector<ModuleSP, 1>
+        old_modules; // This will get filled in if we have a new version
+                     // of the library
     bool did_create_module = false;
     FileSpecList search_paths = GetExecutableSearchPaths();
     // If there are image search path entries, try to use them first to acquire
@@ -1985,7 +1986,7 @@ ModuleSP Target::GetOrCreateModule(const ModuleSpec &module_spec, bool notify,
         transformed_spec.GetFileSpec().GetFilename() =
             module_spec.GetFileSpec().GetFilename();
         error = ModuleList::GetSharedModule(transformed_spec, module_sp,
-                                            &search_paths, &old_module_sp,
+                                            &search_paths, &old_modules,
                                             &did_create_module);
       }
     }
@@ -2003,7 +2004,7 @@ ModuleSP Target::GetOrCreateModule(const ModuleSpec &module_spec, bool notify,
         // We have a UUID, it is OK to check the global module list...
         error =
             ModuleList::GetSharedModule(module_spec, module_sp, &search_paths,
-                                        &old_module_sp, &did_create_module);
+                                        &old_modules, &did_create_module);
       }
 
       if (!module_sp) {
@@ -2012,7 +2013,7 @@ ModuleSP Target::GetOrCreateModule(const ModuleSpec &module_spec, bool notify,
         if (m_platform_sp) {
           error = m_platform_sp->GetSharedModule(
               module_spec, m_process_sp.get(), module_sp, &search_paths,
-              &old_module_sp, &did_create_module);
+              &old_modules, &did_create_module);
         } else {
           error.SetErrorString("no platform is currently set");
         }
@@ -2063,18 +2064,18 @@ ModuleSP Target::GetOrCreateModule(const ModuleSpec &module_spec, bool notify,
         // this target. So let's remove the UUID from the module list, and look
         // in the target's module list. Only do this if there is SOMETHING else
         // in the module spec...
-        if (!old_module_sp) {
-          if (module_spec.GetUUID().IsValid() &&
-              !module_spec.GetFileSpec().GetFilename().IsEmpty() &&
-              !module_spec.GetFileSpec().GetDirectory().IsEmpty()) {
-            ModuleSpec module_spec_copy(module_spec.GetFileSpec());
-            module_spec_copy.GetUUID().Clear();
-
-            ModuleList found_modules;
-            m_images.FindModules(module_spec_copy, found_modules);
-            if (found_modules.GetSize() == 1)
-              old_module_sp = found_modules.GetModuleAtIndex(0);
-          }
+        if (module_spec.GetUUID().IsValid() &&
+            !module_spec.GetFileSpec().GetFilename().IsEmpty() &&
+            !module_spec.GetFileSpec().GetDirectory().IsEmpty()) {
+          ModuleSpec module_spec_copy(module_spec.GetFileSpec());
+          module_spec_copy.GetUUID().Clear();
+
+          ModuleList found_modules;
+          m_images.FindModules(module_spec_copy, found_modules);
+          found_modules.ForEach([&](const ModuleSP &found_module) -> bool {
+            old_modules.push_back(found_module);
+            return true;
+          });
         }
 
         // Preload symbols outside of any lock, so hopefully we can do this for
@@ -2082,14 +2083,67 @@ ModuleSP Target::GetOrCreateModule(const ModuleSpec &module_spec, bool notify,
         if (GetPreloadSymbols())
           module_sp->PreloadSymbols();
 
-        if (old_module_sp && m_images.GetIndexForModule(old_module_sp.get()) !=
-                                 LLDB_INVALID_INDEX32) {
-          m_images.ReplaceModule(old_module_sp, module_sp);
+        llvm::SmallVector<ModuleSP, 1> replaced_modules;
+        for (ModuleSP &old_module_sp : old_modules) {
+          if (m_images.GetIndexForModule(old_module_sp.get()) !=
+              LLDB_INVALID_INDEX32) {
+            if (replaced_modules.empty())
+              m_images.ReplaceModule(old_module_sp, module_sp);
+            else
+              m_images.Remove(old_module_sp);
+
+            replaced_modules.push_back(std::move(old_module_sp));
+          }
+        }
+
+        if (replaced_modules.size() > 1) {
+          // The same new module replaced multiple old modules
+          // simultaneously.  It's not clear this should ever
+          // happen (if we always replace old modules as we add
+          // new ones, presumably we should never have more than
+          // one old one).  If there are legitimate cases where
+          // this happens, then the ModuleList::Notifier interface
+          // may need to be adjusted to allow reporting this.
+          // In the meantime, just log that this has happened; just
+          // above we called ReplaceModule on the first one, and Remove
+          // on the rest.
+          if (Log *log = GetLogIfAnyCategoriesSet(LIBLLDB_LOG_TARGET |
+                                                  LIBLLDB_LOG_MODULES)) {
+            StreamString message;
+            auto dump = [&message](Module &dump_module) -> void {
+              UUID dump_uuid = dump_module.GetUUID();
+
+              message << '[';
+              dump_module.GetDescription(message.AsRawOstream());
+              message << " (uuid ";
+
+              if (dump_uuid.IsValid())
+                dump_uuid.Dump(&message);
+              else
+                message << "not specified";
+
+              message << ")]";
+            };
+
+            message << "New module ";
+            dump(*module_sp);
+            message.AsRawOstream()
+                << llvm::formatv(" simultaneously replaced {0} old modules: ",
+                                 replaced_modules.size());
+            for (ModuleSP &replaced_module_sp : replaced_modules)
+              dump(*replaced_module_sp);
+
+            log->PutString(message.GetString());
+          }
+        }
+
+        if (replaced_modules.empty())
+          m_images.Append(module_sp, notify);
+
+        for (ModuleSP &old_module_sp : replaced_modules) {
           Module *old_module_ptr = old_module_sp.get();
           old_module_sp.reset();
           ModuleList::RemoveSharedModuleIfOrphaned(old_module_ptr);
-        } else {
-          m_images.Append(module_sp, notify);
         }
       } else
         module_sp.reset();