Merge commit '5009d66cabff' from apple/stable/20200714 into swift/main

 Conflicts:
	lldb/packages/Python/lldbsuite/test/lldbtest.py

Author: Teemperor

lldb/bindings/interface/SBModule.i

@@ -356,6 +356,17 @@ public:
     static uint32_t
     GetNumberAllocatedModules();
 
+    %feature("docstring", "
+    Removes all modules which are no longer needed by any part of LLDB from
+    the module cache.
+
+    This is an implementation detail exposed for testing and should not be
+    relied upon. Use SBDebugger::MemoryPressureDetected instead to reduce
+    LLDB's memory consumption during execution.
+    ") GarbageCollectAllocatedModules;
+    static void
+    GarbageCollectAllocatedModules();
+
     STRING_EXTENSION(SBModule)
 
 #ifdef SWIGPYTHON

lldb/include/lldb/API/SBModule.h

@@ -293,6 +293,9 @@ class LLDB_API SBModule {
   /// Get the number of global modules.
   static uint32_t GetNumberAllocatedModules();
 
+  /// Remove any global modules which are no longer needed.
+  static void GarbageCollectAllocatedModules();
+
 private:
   friend class SBAddress;
   friend class SBFrame;

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

@@ -1029,6 +1029,17 @@ def tearDown(self):
         lldb.SBDebugger.Destroy(self.dbg)
         del self.dbg
 
+        # All modules should be orphaned now so that they can be cleared from
+        # the shared module cache.
+        lldb.SBModule.GarbageCollectAllocatedModules()
+
+        # Modules are not orphaned during reproducer replay because they're
+        # leaked on purpose.
+        if not configuration.is_reproducer():
+            # Assert that the global module cache is empty.
+            # (rdar://problem/64424164) self.assertEqual(lldb.SBModule.GetNumberAllocatedModules(), 0)
+
+
     # =========================================================
     # Various callbacks to allow introspection of test progress
     # =========================================================
@@ -1989,13 +2000,9 @@ def tearDown(self):
         for target in targets:
             self.dbg.DeleteTarget(target)
 
-        # Modules are not orphaned during reproducer replay because they're
-        # leaked on purpose.
         if not configuration.is_reproducer():
             # Assert that all targets are deleted.
-            assert self.dbg.GetNumTargets() == 0
-            # Assert that the global module cache is empty.
-            # (rdar://problem/64424164) assert lldb.SBModule.GetNumberAllocatedModules() == 0
+            self.assertEqual(self.dbg.GetNumTargets(), 0)
 
         # Do this last, to make sure it's in reverse order from how we setup.
         Base.tearDown(self)

lldb/source/API/SBModule.cpp

@@ -714,6 +714,13 @@ uint32_t SBModule::GetNumberAllocatedModules() {
   return Module::GetNumberAllocatedModules();
 }
 
+void SBModule::GarbageCollectAllocatedModules() {
+  LLDB_RECORD_STATIC_METHOD_NO_ARGS(void, SBModule,
+                                    GarbageCollectAllocatedModules);
+  const bool mandatory = false;
+  ModuleList::RemoveOrphanSharedModules(mandatory);
+}
+
 namespace lldb_private {
 namespace repro {