Index: lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
===================================================================
--- lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -2186,9 +2186,10 @@
 std::vector<DWARFDIE> DWARFASTParserClang::GetDIEForDeclContext(
     lldb_private::CompilerDeclContext decl_context) {
   std::vector<DWARFDIE> result;
-  for (auto it = m_decl_ctx_to_die.find(
-           (clang::DeclContext *)decl_context.GetOpaqueDeclContext());
-       it != m_decl_ctx_to_die.end(); it++)
+  auto opaque_decl_ctx =
+      (clang::DeclContext *)decl_context.GetOpaqueDeclContext();
+  for (auto it = m_decl_ctx_to_die.find(opaque_decl_ctx);
+       it != m_decl_ctx_to_die.end() && it->first == opaque_decl_ctx; it++)
     result.push_back(it->second);
   return result;
 }
Index: lldb/trunk/unittests/SymbolFile/DWARF/CMakeLists.txt
===================================================================
--- lldb/trunk/unittests/SymbolFile/DWARF/CMakeLists.txt
+++ lldb/trunk/unittests/SymbolFile/DWARF/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_lldb_unittest(SymbolFileDWARFTests
+  DWARFASTParserClangTests.cpp
   SymbolFileDWARFTests.cpp
 
   LINK_LIBS
Index: lldb/trunk/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp
===================================================================
--- lldb/trunk/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp
+++ lldb/trunk/unittests/SymbolFile/DWARF/DWARFASTParserClangTests.cpp
@@ -0,0 +1,47 @@
+//===-- DWARFASTParserClangTests.cpp ----------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "gtest/gtest.h"
+
+#include "Plugins/SymbolFile/DWARF/DWARFASTParserClang.h"
+#include "Plugins/SymbolFile/DWARF/DWARFDIE.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+namespace {
+class DWARFASTParserClangStub : public DWARFASTParserClang {
+public:
+  using DWARFASTParserClang::DWARFASTParserClang;
+  using DWARFASTParserClang::LinkDeclContextToDIE;
+};
+} // namespace
+
+// If your implementation needs to dereference the dummy pointers we are
+// defining here, causing this test to fail, feel free to delete it.
+TEST(DWARFASTParserClangTests,
+     TestGetDIEForDeclContextReturnsOnlyMatchingEntries) {
+  ClangASTContext ast_ctx;
+  DWARFASTParserClangStub ast_parser(ast_ctx);
+
+  DWARFUnit *unit = nullptr;
+  DWARFDIE die1(unit, (DWARFDebugInfoEntry *)1LL);
+  DWARFDIE die2(unit, (DWARFDebugInfoEntry *)2LL);
+  DWARFDIE die3(unit, (DWARFDebugInfoEntry *)3LL);
+  DWARFDIE die4(unit, (DWARFDebugInfoEntry *)4LL);
+  ast_parser.LinkDeclContextToDIE((clang::DeclContext *)1LL, die1);
+  ast_parser.LinkDeclContextToDIE((clang::DeclContext *)2LL, die2);
+  ast_parser.LinkDeclContextToDIE((clang::DeclContext *)2LL, die3);
+  ast_parser.LinkDeclContextToDIE((clang::DeclContext *)3LL, die4);
+
+  auto die_list = ast_parser.GetDIEForDeclContext(
+      CompilerDeclContext(nullptr, (clang::DeclContext *)2LL));
+  ASSERT_EQ(2u, die_list.size());
+  ASSERT_EQ(die2, die_list[0]);
+  ASSERT_EQ(die3, die_list[1]);
+}