Vendor import of lldb trunk r321414:vendor/lldb/lldb-trunk-r321426vendor/lldb/lldb-trunk-r321414

https://llvm.org/svn/llvm-project/lldb/trunk@321414

40 files changed, 367 insertions, 170 deletions

diff --git a/include/lldb/Interpreter/OptionValueFileSpec.h b/include/lldb/Interpreter/OptionValueFileSpec.h
index b53c03471e2b..293ecd0d8054 100644
--- a/include/lldb/Interpreter/OptionValueFileSpec.h
+++ b/include/lldb/Interpreter/OptionValueFileSpec.h
@@ -77,7 +77,7 @@ public:
 
   void SetDefaultValue(const FileSpec &value) { m_default_value = value; }
 
-  const lldb::DataBufferSP &GetFileContents(bool null_terminate);
+  const lldb::DataBufferSP &GetFileContents();
 
   void SetCompletionMask(uint32_t mask) { m_completion_mask = mask; }
 
diff --git a/include/lldb/Symbol/ObjectFile.h b/include/lldb/Symbol/ObjectFile.h
index 3f9250af7e08..dff802522da8 100644
--- a/include/lldb/Symbol/ObjectFile.h
+++ b/include/lldb/Symbol/ObjectFile.h
@@ -879,6 +879,9 @@ protected:
 
   ConstString GetNextSyntheticSymbolName();
 
+  static lldb::DataBufferSP MapFileData(const FileSpec &file, uint64_t Size,
+                                        uint64_t Offset);
+
 private:
   DISALLOW_COPY_AND_ASSIGN(ObjectFile);
 };
diff --git a/include/lldb/Target/Target.h b/include/lldb/Target/Target.h
index 242ec14165eb..a5d200069810 100644
--- a/include/lldb/Target/Target.h
+++ b/include/lldb/Target/Target.h
@@ -161,7 +161,7 @@ public:
 
   lldb::LanguageType GetLanguage() const;
 
-  const char *GetExpressionPrefixContentsAsCString();
+  llvm::StringRef GetExpressionPrefixContents();
 
   bool GetUseHexImmediates() const;
 
diff --git a/include/lldb/Utility/DataBufferLLVM.h b/include/lldb/Utility/DataBufferLLVM.h
index 737e2d019044..0eb229cffbe2 100644
--- a/include/lldb/Utility/DataBufferLLVM.h
+++ b/include/lldb/Utility/DataBufferLLVM.h
@@ -17,7 +17,7 @@
 #include <stdint.h> // for uint8_t, uint64_t
 
 namespace llvm {
-class MemoryBuffer;
+class WritableMemoryBuffer;
 class Twine;
 }
 
@@ -28,10 +28,10 @@ public:
   ~DataBufferLLVM();
 
   static std::shared_ptr<DataBufferLLVM>
-  CreateSliceFromPath(const llvm::Twine &Path, uint64_t Size, uint64_t Offset, bool Private = false);
+  CreateSliceFromPath(const llvm::Twine &Path, uint64_t Size, uint64_t Offset);
 
   static std::shared_ptr<DataBufferLLVM>
-  CreateFromPath(const llvm::Twine &Path, bool NullTerminate = false, bool Private = false);
+  CreateFromPath(const llvm::Twine &Path);
 
   uint8_t *GetBytes() override;
   const uint8_t *GetBytes() const override;
@@ -42,10 +42,9 @@ public:
 private:
   /// \brief Construct a DataBufferLLVM from \p Buffer.  \p Buffer must be a
   /// valid pointer.
-  explicit DataBufferLLVM(std::unique_ptr<llvm::MemoryBuffer> Buffer);
-  const uint8_t *GetBuffer() const;
+  explicit DataBufferLLVM(std::unique_ptr<llvm::WritableMemoryBuffer> Buffer);
 
-  std::unique_ptr<llvm::MemoryBuffer> Buffer;
+  std::unique_ptr<llvm::WritableMemoryBuffer> Buffer;
 };
 }
 
diff --git a/packages/Python/lldbsuite/test/expression_command/radar_9673664/TestExprHelpExamples.py b/packages/Python/lldbsuite/test/expression_command/radar_9673664/TestExprHelpExamples.py
index a6c0c050c468..4fc2463b25a8 100644
--- a/packages/Python/lldbsuite/test/expression_command/radar_9673664/TestExprHelpExamples.py
+++ b/packages/Python/lldbsuite/test/expression_command/radar_9673664/TestExprHelpExamples.py
@@ -42,7 +42,7 @@ class Radar9673644TestCase(TestBase):
 
         # rdar://problem/9673664 lldb expression evaluation problem
 
-        self.expect('expr char c[] = "foo"; c[0]',
+        self.expect('expr char str[] = "foo"; str[0]',
                     substrs=["'f'"])
         # runCmd: expr char c[] = "foo"; c[0]
         # output: (char) $0 = 'f'
diff --git a/packages/Python/lldbsuite/test/expression_command/top-level/test.cpp b/packages/Python/lldbsuite/test/expression_command/top-level/test.cpp
index ce2ea3bbb131..5a978743596a 100644
--- a/packages/Python/lldbsuite/test/expression_command/top-level/test.cpp
+++ b/packages/Python/lldbsuite/test/expression_command/top-level/test.cpp
@@ -42,11 +42,11 @@ public:
             int i;
         } s = { 15 };
     
-        int as[4] = { 2, 3, 4, 5 };
+        int numbers[4] = { 2, 3, 4, 5 };
     
-        for (signed char a : as)
+        for (signed char number: numbers)
         {
-            s.i -= a;
+            s.i -= number;
         }
     
         return s.i;
@@ -94,14 +94,14 @@ public:
 
 int doTest()
 {
-    int a = m.memberResult();
-    a += MyClass::staticResult();
-    a += m.externResult();
-    a += MyEnum::myEnumThree;
-    a += myEnumOne;
-    a += AnotherClass().complicatedFunction();
-    a += DiamondD(3).accessor();
-    return a;
+    int accumulator = m.memberResult();
+    accumulator += MyClass::staticResult();
+    accumulator += m.externResult();
+    accumulator += MyEnum::myEnumThree;
+    accumulator += myEnumOne;
+    accumulator += AnotherClass().complicatedFunction();
+    accumulator += DiamondD(3).accessor();
+    return accumulator;
 }
 
 // --
diff --git a/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py b/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py
index 965af3e4910a..550eae85e1d6 100644
--- a/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py
+++ b/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py
@@ -29,12 +29,14 @@ class ExecTestCase(TestBase):
     mydir = TestBase.compute_mydir(__file__)
 
     @skipUnlessDarwin
+    @expectedFailureAll(oslist=['macosx'], bugnumber="rdar://36134350") # when building with cmake on green gragon or on ci.swift.org, this test fails.
     @expectedFailureAll(archs=['i386'], bugnumber="rdar://28656532")
     @expectedFailureAll(oslist=["ios", "tvos", "watchos", "bridgeos"], bugnumber="rdar://problem/34559552") # this exec test has problems on ios systems
     def test_hitting_exec (self):
         self.do_test(False)
 
     @skipUnlessDarwin
+    @expectedFailureAll(oslist=['macosx'], bugnumber="rdar://36134350") # when building with cmake on green gragon or on ci.swift.org, this test fails.
     @expectedFailureAll(archs=['i386'], bugnumber="rdar://28656532")
     @expectedFailureAll(oslist=["ios", "tvos", "watchos", "bridgeos"], bugnumber="rdar://problem/34559552") # this exec test has problems on ios systems
     def test_skipping_exec (self):
diff --git a/packages/Python/lldbsuite/test/functionalities/postmortem/minidump-new/TestMiniDumpNew.py b/packages/Python/lldbsuite/test/functionalities/postmortem/minidump-new/TestMiniDumpNew.py
index 178bb678df7c..4e587b92c1d2 100644
--- a/packages/Python/lldbsuite/test/functionalities/postmortem/minidump-new/TestMiniDumpNew.py
+++ b/packages/Python/lldbsuite/test/functionalities/postmortem/minidump-new/TestMiniDumpNew.py
@@ -117,7 +117,7 @@ class MiniDumpNewTestCase(TestBase):
         thread = self.process.GetThreadAtIndex(0)
         self.assertEqual(thread.GetStopReason(), lldb.eStopReasonNone)
         stop_description = thread.GetStopDescription(256)
-        self.assertEqual(stop_description, None)
+        self.assertEqual(stop_description, "")
 
     def do_test_deeper_stack(self, binary, core, pid):
         target = self.dbg.CreateTarget(binary)
diff --git a/packages/Python/lldbsuite/test/lang/c/conflicting-symbol/TestConflictingSymbol.py b/packages/Python/lldbsuite/test/lang/c/conflicting-symbol/TestConflictingSymbol.py
index d3327700bfd2..328c383b38fb 100644
--- a/packages/Python/lldbsuite/test/lang/c/conflicting-symbol/TestConflictingSymbol.py
+++ b/packages/Python/lldbsuite/test/lang/c/conflicting-symbol/TestConflictingSymbol.py
@@ -16,6 +16,13 @@ class TestConflictingSymbols(TestBase):
     mydir = TestBase.compute_mydir(__file__)
     NO_DEBUG_INFO_TESTCASE = True
 
+    def setUp(self):
+        TestBase.setUp(self)
+
+        self.One_line = line_number('One/One.c', '// break here')
+        self.Two_line = line_number('Two/Two.c', '// break here')
+        self.main_line = line_number('main.c', '// break here')
+
     def test_conflicting_symbols(self):
         self.build()
         exe = os.path.join(os.getcwd(), "a.out")
@@ -27,15 +34,12 @@ class TestConflictingSymbols(TestBase):
         environment = self.registerSharedLibrariesWithTarget(
             target, ['One', 'Two'])
 
-        One_line = line_number('One/One.c', '// break here')
-        Two_line = line_number('Two/Two.c', '// break here')
-        main_line = line_number('main.c', '// break here')
         lldbutil.run_break_set_command(
-            self, 'breakpoint set -f One.c -l %s' % (One_line))
+            self, 'breakpoint set -f One.c -l %s' % (self.One_line))
         lldbutil.run_break_set_command(
-            self, 'breakpoint set -f Two.c -l %s' % (Two_line))
+            self, 'breakpoint set -f Two.c -l %s' % (self.Two_line))
         lldbutil.run_break_set_by_file_and_line(
-            self, 'main.c', main_line, num_expected_locations=1, loc_exact=True)
+            self, 'main.c', self.main_line, num_expected_locations=1, loc_exact=True)
 
         process = target.LaunchSimple(
             None, environment, self.get_process_working_directory())
@@ -88,3 +92,32 @@ class TestConflictingSymbols(TestBase):
             error=True,
             substrs=[
                 "Multiple internal symbols"])
+
+    @expectedFailureAll(bugnumber="llvm.org/pr35043")
+    def test_shadowed(self):
+        self.build()
+        exe = os.path.join(os.getcwd(), "a.out")
+        target = self.dbg.CreateTarget("a.out")
+        self.assertTrue(target, VALID_TARGET)
+
+        # Register our shared libraries for remote targets so they get
+        # automatically uploaded
+        environment = self.registerSharedLibrariesWithTarget(
+            target, ['One', 'Two'])
+
+        lldbutil.run_break_set_by_file_and_line(self, 'main.c', self.main_line)
+
+        process = target.LaunchSimple(
+            None, environment, self.get_process_working_directory())
+        self.assertTrue(process, PROCESS_IS_VALID)
+
+        # The stop reason of the thread should be breakpoint.
+        self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
+                    substrs=['stopped',
+                             'stop reason = breakpoint'])
+
+        # As we are shadowing the conflicting symbol, there should be no
+        # ambiguity in this expression.
+        self.expect(
+            "expr int conflicting_symbol = 474747; conflicting_symbol",
+            substrs=[ "474747"])
diff --git a/packages/Python/lldbsuite/test/lang/cpp/lambdas/main.cpp b/packages/Python/lldbsuite/test/lang/cpp/lambdas/main.cpp
index 3cce3baf2924..0432cc1357da 100644
--- a/packages/Python/lldbsuite/test/lang/cpp/lambdas/main.cpp
+++ b/packages/Python/lldbsuite/test/lang/cpp/lambdas/main.cpp
@@ -11,7 +11,7 @@
 
 int main (int argc, char const *argv[])
 {
-    printf("Stop here\n"); //% self.runCmd("expression auto $add = [](int a, int b) { return a + b; }")
+    printf("Stop here\n"); //% self.runCmd("expression auto $add = [](int first, int second) { return first + second; }")
                            //% self.expect("expression $add(2,3)", substrs = ['= 5'])
     return 0;
 }
diff --git a/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/Makefile b/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/Makefile
new file mode 100644
index 000000000000..f3414925f32b
--- /dev/null
+++ b/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/Makefile
@@ -0,0 +1,6 @@
+LEVEL = ../../../make
+
+C_SOURCES := main.c
+EXE := read-mem-cstring
+
+include $(LEVEL)/Makefile.rules
diff --git a/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/TestReadMemCString.py b/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/TestReadMemCString.py
new file mode 100644
index 000000000000..6302711606c5
--- /dev/null
+++ b/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/TestReadMemCString.py
@@ -0,0 +1,57 @@
+"""Test reading c-strings from memory via SB API."""
+
+from __future__ import print_function
+
+import os
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestReadMemCString(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def test_read_memory_c_string(self):
+        """Test corner case behavior of SBProcess::ReadCStringFromMemory"""
+        self.build()
+	self.dbg.SetAsync(False)
+
+        self.main_source = "main.c"
+	self.main_source_spec = lldb.SBFileSpec(self.main_source)
+	self.exe = os.path.join(os.getcwd(), "read-mem-cstring")
+
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
+            self, 'breakpoint here', self.main_source_spec, None, self.exe)
+
+	frame = thread.GetFrameAtIndex(0)
+        
+        err = lldb.SBError()
+
+        empty_str_addr = frame.FindVariable("empty_string").GetValueAsUnsigned(err)
+        self.assertTrue(err.Success())
+        self.assertTrue(empty_str_addr != lldb.LLDB_INVALID_ADDRESS)
+
+        one_letter_str_addr = frame.FindVariable("one_letter_string").GetValueAsUnsigned(err)
+        self.assertTrue(err.Success())
+        self.assertTrue(one_letter_str_addr != lldb.LLDB_INVALID_ADDRESS)
+
+        invalid_memory_str_addr = frame.FindVariable("invalid_memory_string").GetValueAsUnsigned(err)
+        self.assertTrue(err.Success())
+        self.assertTrue(invalid_memory_str_addr != lldb.LLDB_INVALID_ADDRESS)
+
+        # Important:  An empty (0-length) c-string must come back as a Python string, not a
+        # None object.
+        empty_str = process.ReadCStringFromMemory(empty_str_addr, 2048, err)
+        self.assertTrue(err.Success())
+        self.assertTrue(empty_str == "")
+
+        one_letter_string = process.ReadCStringFromMemory(one_letter_str_addr, 2048, err)
+        self.assertTrue(err.Success())
+        self.assertTrue(one_letter_string == "1")
+
+        invalid_memory_string = process.ReadCStringFromMemory(invalid_memory_str_addr, 2048, err)
+        self.assertTrue(err.Fail())
+        self.assertTrue(invalid_memory_string == "" or invalid_memory_string == None)
diff --git a/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/main.c b/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/main.c
new file mode 100644
index 000000000000..03c667417129
--- /dev/null
+++ b/packages/Python/lldbsuite/test/python_api/process/read-mem-cstring/main.c
@@ -0,0 +1,11 @@
+#include <stdlib.h>
+int main ()
+{
+   const char *empty_string = "";
+   const char *one_letter_string = "1";
+   // This expects that lower 4k of memory will be mapped unreadable, which most
+   // OSs do (to catch null pointer dereferences).
+   const char *invalid_memory_string = (char*)0x100;
+
+   return empty_string[0] + one_letter_string[0]; // breakpoint here
+}
diff --git a/scripts/Python/python-typemaps.swig b/scripts/Python/python-typemaps.swig
index df16a6d27b3b..29e5d9b156df 100644
--- a/scripts/Python/python-typemaps.swig
+++ b/scripts/Python/python-typemaps.swig
@@ -102,7 +102,8 @@
 %typemap(argout) (char *dst, size_t dst_len) {
    Py_XDECREF($result);   /* Blow away any previous result */
    if (result == 0) {
-      $result = Py_None;
+      lldb_private::PythonString string("");
+      $result = string.release();
       Py_INCREF($result);
    } else {
       llvm::StringRef ref(static_cast<const char*>($1), result);
diff --git a/source/Interpreter/OptionValueFileSpec.cpp b/source/Interpreter/OptionValueFileSpec.cpp
index b235d4ac6863..7d17ddec4f9c 100644
--- a/source/Interpreter/OptionValueFileSpec.cpp
+++ b/source/Interpreter/OptionValueFileSpec.cpp
@@ -113,14 +113,12 @@ size_t OptionValueFileSpec::AutoComplete(
   return matches.GetSize();
 }
 
-const lldb::DataBufferSP &
-OptionValueFileSpec::GetFileContents(bool null_terminate) {
+const lldb::DataBufferSP &OptionValueFileSpec::GetFileContents() {
   if (m_current_value) {
     const auto file_mod_time = FileSystem::GetModificationTime(m_current_value);
     if (m_data_sp && m_data_mod_time == file_mod_time)
       return m_data_sp;
-    m_data_sp = DataBufferLLVM::CreateFromPath(m_current_value.GetPath(),
-                                               null_terminate);
+    m_data_sp = DataBufferLLVM::CreateFromPath(m_current_value.GetPath());
     m_data_mod_time = file_mod_time;
   }
   return m_data_sp;
diff --git a/source/Plugins/Disassembler/llvm/DisassemblerLLVMC.cpp b/source/Plugins/Disassembler/llvm/DisassemblerLLVMC.cpp
index 21e19bf2b127..a61abb9898ac 100644
--- a/source/Plugins/Disassembler/llvm/DisassemblerLLVMC.cpp
+++ b/source/Plugins/Disassembler/llvm/DisassemblerLLVMC.cpp
@@ -1127,6 +1127,11 @@ DisassemblerLLVMC::DisassemblerLLVMC(const ArchSpec &arch,
       features_str += "+dspr2,";
   }
 
+  // If any AArch64 variant, enable the ARMv8.2 ISA
+  // extensions so we can disassemble newer instructions.
+  if (triple.getArch() == llvm::Triple::aarch64)
+    features_str += "+v8.2a";
+
   m_disasm_ap.reset(new LLVMCDisassembler(triple_str, cpu, features_str.c_str(),
                                           flavor, *this));
   if (!m_disasm_ap->IsValid()) {
diff --git a/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index 17d892450e4d..36027dde0432 100644
--- a/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -24,7 +24,6 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Utility/ArchSpec.h"
 #include "lldb/Utility/DataBufferHeap.h"
-#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Status.h"
 #include "lldb/Utility/Stream.h"
@@ -406,8 +405,7 @@ ObjectFile *ObjectFileELF::CreateInstance(const lldb::ModuleSP &module_sp,
                                           lldb::offset_t file_offset,
                                           lldb::offset_t length) {
   if (!data_sp) {
-    data_sp =
-        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset, true);
+    data_sp = MapFileData(*file, length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -424,8 +422,7 @@ ObjectFile *ObjectFileELF::CreateInstance(const lldb::ModuleSP &module_sp,
 
   // Update the data to contain the entire file if it doesn't already
   if (data_sp->GetByteSize() < length) {
-    data_sp =
-        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset, true);
+    data_sp = MapFileData(*file, length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -684,8 +681,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
           size_t section_header_end = header.e_shoff + header.e_shentsize;
           if (header.HasHeaderExtension() &&
             section_header_end > data_sp->GetByteSize()) {
-            data_sp = DataBufferLLVM::CreateSliceFromPath(
-                file.GetPath(), section_header_end, file_offset);
+            data_sp = MapFileData(file, section_header_end, file_offset);
             if (data_sp) {
               data.SetData(data_sp);
               lldb::offset_t header_offset = data_offset;
@@ -698,8 +694,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
           section_header_end =
               header.e_shoff + header.e_shnum * header.e_shentsize;
           if (section_header_end > data_sp->GetByteSize()) {
-            data_sp = DataBufferLLVM::CreateSliceFromPath(
-                file.GetPath(), section_header_end, file_offset);
+            data_sp = MapFileData(file, section_header_end, file_offset);
             if (data_sp)
               data.SetData(data_sp);
           }
@@ -741,8 +736,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
                 size_t program_headers_end =
                     header.e_phoff + header.e_phnum * header.e_phentsize;
                 if (program_headers_end > data_sp->GetByteSize()) {
-                  data_sp = DataBufferLLVM::CreateSliceFromPath(
-                      file.GetPath(), program_headers_end, file_offset);
+                  data_sp = MapFileData(file, program_headers_end, file_offset);
                   if (data_sp)
                     data.SetData(data_sp);
                 }
@@ -757,8 +751,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
                 }
 
                 if (segment_data_end > data_sp->GetByteSize()) {
-                  data_sp = DataBufferLLVM::CreateSliceFromPath(
-                      file.GetPath(), segment_data_end, file_offset);
+                  data_sp = MapFileData(file, segment_data_end, file_offset);
                   if (data_sp)
                     data.SetData(data_sp);
                 }
@@ -767,8 +760,7 @@ size_t ObjectFileELF::GetModuleSpecifications(
                     CalculateELFNotesSegmentsCRC32(program_headers, data);
               } else {
                 // Need to map entire file into memory to calculate the crc.
-                data_sp = DataBufferLLVM::CreateSliceFromPath(file.GetPath(), -1,
-                                                         file_offset);
+                data_sp = MapFileData(file, -1, file_offset);
                 if (data_sp) {
                   data.SetData(data_sp);
                   gnu_debuglink_crc = calc_gnu_debuglink_crc32(
diff --git a/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index df334f88ee3b..e6941c9f6ed6 100644
--- a/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -38,7 +38,7 @@
 #include "lldb/Target/Thread.h"
 #include "lldb/Target/ThreadList.h"
 #include "lldb/Utility/ArchSpec.h"
-#include "lldb/Utility/DataBufferLLVM.h"
+#include "lldb/Utility/DataBuffer.h"
 #include "lldb/Utility/FileSpec.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Status.h"
@@ -862,8 +862,7 @@ ObjectFile *ObjectFileMachO::CreateInstance(const lldb::ModuleSP &module_sp,
                                             lldb::offset_t file_offset,
                                             lldb::offset_t length) {
   if (!data_sp) {
-    data_sp =
-        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
+    data_sp = MapFileData(*file, length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -874,8 +873,7 @@ ObjectFile *ObjectFileMachO::CreateInstance(const lldb::ModuleSP &module_sp,
 
   // Update the data to contain the entire file if it doesn't already
   if (data_sp->GetByteSize() < length) {
-    data_sp =
-        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
+    data_sp = MapFileData(*file, length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -914,8 +912,7 @@ size_t ObjectFileMachO::GetModuleSpecifications(
       size_t header_and_load_cmds =
           header.sizeofcmds + MachHeaderSizeFromMagic(header.magic);
       if (header_and_load_cmds >= data_sp->GetByteSize()) {
-        data_sp = DataBufferLLVM::CreateSliceFromPath(
-            file.GetPath(), header_and_load_cmds, file_offset);
+        data_sp = MapFileData(file, header_and_load_cmds, file_offset);
         data.SetData(data_sp);
         data_offset = MachHeaderSizeFromMagic(header.magic);
       }
@@ -1127,8 +1124,7 @@ bool ObjectFileMachO::ParseHeader() {
                   ReadMemory(process_sp, m_memory_addr, header_and_lc_size);
             } else {
               // Read in all only the load command data from the file on disk
-              data_sp = DataBufferLLVM::CreateSliceFromPath(
-                  m_file.GetPath(), header_and_lc_size, m_file_offset);
+              data_sp = MapFileData(m_file, header_and_lc_size, m_file_offset);
               if (data_sp->GetByteSize() != header_and_lc_size)
                 return false;
             }
@@ -2100,9 +2096,8 @@ UUID ObjectFileMachO::GetSharedCacheUUID(FileSpec dyld_shared_cache,
                                          const ByteOrder byte_order,
                                          const uint32_t addr_byte_size) {
   UUID dsc_uuid;
-  DataBufferSP DscData = DataBufferLLVM::CreateSliceFromPath(
-      dyld_shared_cache.GetPath(),
-      sizeof(struct lldb_copy_dyld_cache_header_v1), 0);
+  DataBufferSP DscData = MapFileData(
+      dyld_shared_cache, sizeof(struct lldb_copy_dyld_cache_header_v1), 0);
   if (!DscData)
     return dsc_uuid;
   DataExtractor dsc_header_data(DscData, byte_order, addr_byte_size);
@@ -2708,9 +2703,8 @@ size_t ObjectFileMachO::ParseSymtab() {
 
       // Process the dyld shared cache header to find the unmapped symbols
 
-      DataBufferSP dsc_data_sp = DataBufferLLVM::CreateSliceFromPath(
-          dsc_filespec.GetPath(), sizeof(struct lldb_copy_dyld_cache_header_v1),
-          0);
+      DataBufferSP dsc_data_sp = MapFileData(
+          dsc_filespec, sizeof(struct lldb_copy_dyld_cache_header_v1), 0);
       if (!dsc_uuid.IsValid()) {
         dsc_uuid = GetSharedCacheUUID(dsc_filespec, byte_order, addr_byte_size);
       }
@@ -2742,11 +2736,9 @@ size_t ObjectFileMachO::ParseSymtab() {
         if (uuid_match &&
             mappingOffset >= sizeof(struct lldb_copy_dyld_cache_header_v1)) {
 
-          DataBufferSP dsc_mapping_info_data_sp =
-              DataBufferLLVM::CreateSliceFromPath(
-                  dsc_filespec.GetPath(),
-                  sizeof(struct lldb_copy_dyld_cache_mapping_info),
-                  mappingOffset);
+          DataBufferSP dsc_mapping_info_data_sp = MapFileData(
+              dsc_filespec, sizeof(struct lldb_copy_dyld_cache_mapping_info),
+              mappingOffset);
 
           DataExtractor dsc_mapping_info_data(dsc_mapping_info_data_sp,
                                               byte_order, addr_byte_size);
@@ -2770,9 +2762,7 @@ size_t ObjectFileMachO::ParseSymtab() {
           if (localSymbolsOffset && localSymbolsSize) {
             // Map the local symbols
             DataBufferSP dsc_local_symbols_data_sp =
-                DataBufferLLVM::CreateSliceFromPath(dsc_filespec.GetPath(),
-                                               localSymbolsSize,
-                                               localSymbolsOffset);
+                MapFileData(dsc_filespec, localSymbolsSize, localSymbolsOffset);
 
             if (dsc_local_symbols_data_sp) {
               DataExtractor dsc_local_symbols_data(dsc_local_symbols_data_sp,
diff --git a/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp b/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
index 72b1b15f08f8..77bfa7fe0a64 100644
--- a/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
+++ b/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
@@ -22,7 +22,6 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Utility/ArchSpec.h"
 #include "lldb/Utility/DataBufferHeap.h"
-#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/FileSpec.h"
 #include "lldb/Utility/StreamString.h"
 #include "lldb/Utility/Timer.h"
@@ -66,8 +65,7 @@ ObjectFile *ObjectFilePECOFF::CreateInstance(const lldb::ModuleSP &module_sp,
                                              lldb::offset_t file_offset,
                                              lldb::offset_t length) {
   if (!data_sp) {
-    data_sp =
-        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
+    data_sp = MapFileData(file, length, file_offset);
     if (!data_sp)
       return nullptr;
     data_offset = 0;
@@ -78,8 +76,7 @@ ObjectFile *ObjectFilePECOFF::CreateInstance(const lldb::ModuleSP &module_sp,
 
   // Update the data to contain the entire file if it doesn't already
   if (data_sp->GetByteSize() < length) {
-    data_sp =
-        DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
+    data_sp = MapFileData(file, length, file_offset);
     if (!data_sp)
       return nullptr;
   }
@@ -436,8 +433,7 @@ DataExtractor ObjectFilePECOFF::ReadImageData(uint32_t offset, size_t size) {
   if (m_file) {
     // A bit of a hack, but we intend to write to this buffer, so we can't 
     // mmap it.
-    auto buffer_sp =
-        DataBufferLLVM::CreateSliceFromPath(m_file.GetPath(), size, offset, true);
+    auto buffer_sp = MapFileData(m_file, size, offset);
     return DataExtractor(buffer_sp, GetByteOrder(), GetAddressByteSize());
   }
   ProcessSP process_sp(m_process_wp.lock());
diff --git a/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp b/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
index b39aa103f1db..b04d72f755f6 100644
--- a/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
+++ b/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
@@ -1173,7 +1173,7 @@ const char *PlatformDarwin::GetDeveloperDirectory() {
       xcode_dir_path.append("/usr/share/xcode-select/xcode_dir_path");
       temp_file_spec.SetFile(xcode_dir_path, false);
       auto dir_buffer =
-          DataBufferLLVM::CreateFromPath(temp_file_spec.GetPath(), true);
+          DataBufferLLVM::CreateFromPath(temp_file_spec.GetPath());
       if (dir_buffer && dir_buffer->GetByteSize() > 0) {
         llvm::StringRef path_ref(dir_buffer->GetChars());
         // Trim tailing newlines and make sure there is enough room for a null
diff --git a/source/Plugins/Process/MacOSX-Kernel/CommunicationKDP.cpp b/source/Plugins/Process/MacOSX-Kernel/CommunicationKDP.cpp
index 46d522531a5b..3d9f498b1e9a 100644
--- a/source/Plugins/Process/MacOSX-Kernel/CommunicationKDP.cpp
+++ b/source/Plugins/Process/MacOSX-Kernel/CommunicationKDP.cpp
@@ -98,7 +98,7 @@ bool CommunicationKDP::SendRequestAndGetReply(
 #ifdef LLDB_CONFIGURATION_DEBUG
   // NOTE: this only works for packets that are in native endian byte order
   assert(request_packet.GetSize() ==
-         *((uint16_t *)(request_packet.GetData() + 2)));
+         *((const uint16_t *)(request_packet.GetData() + 2)));
 #endif
   lldb::offset_t offset = 1;
   const uint32_t num_retries = 3;
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp b/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
index 1e20a090161d..4d4a4f8c5c7a 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.cpp
@@ -60,6 +60,7 @@ StateType GDBRemoteClientBase::SendContinuePacketAndWaitForResponse(
         continue;
       if (steady_clock::now() >= m_interrupt_time + kInterruptTimeout)
         return eStateInvalid;
+      break;
     }
     case PacketResult::Success:
       break;
diff --git a/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
index 6ae2b225d869..54b12cfb3b8c 100644
--- a/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -1743,8 +1743,8 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
                       "DWARF DW_TAG_array_type DIE at 0x%8.8x has a "
                       "class/union/struct element type DIE 0x%8.8x that is a "
                       "forward declaration, not a complete definition.\nTry "
-                      "compiling the source file with -fno-limit-debug-info or "
-                      "disable -gmodule",
+                      "compiling the source file with -fstandalone-debug or "
+                      "disable -gmodules",
                       die.GetOffset(), type_die_ref.die_offset);
                 else
                   module_sp->ReportError(
@@ -2255,7 +2255,7 @@ bool DWARFASTParserClang::CompleteTypeFromDWARF(const DWARFDIE &die,
                 if (die.GetCU()->GetProducer() ==
                     DWARFCompileUnit::eProducerClang)
                   module->ReportError(":: Try compiling the source file with "
-                                      "-fno-limit-debug-info.");
+                                      "-fstandalone-debug.");
 
                 // We have no choice other than to pretend that the base class
                 // is complete. If we don't do this, clang will crash when we
@@ -3095,7 +3095,7 @@ bool DWARFASTParserClang::ParseChildMembers(
                       "DWARF DIE at 0x%8.8x (class %s) has a member variable "
                       "0x%8.8x (%s) whose type is a forward declaration, not a "
                       "complete definition.\nTry compiling the source file "
-                      "with -fno-limit-debug-info",
+                      "with -fstandalone-debug",
                       parent_die.GetOffset(), parent_die.GetName(),
                       die.GetOffset(), name);
                 else
diff --git a/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp b/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
index 9b98ebe112a2..7802d6f0d859 100644
--- a/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
+++ b/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
@@ -124,6 +124,8 @@ lldb::TypeSP PDBASTParser::CreateLLDBTypeFromPDBType(const PDBSymbol &type) {
   } else if (auto type_def = llvm::dyn_cast<PDBSymbolTypeTypedef>(&type)) {
     lldb_private::Type *target_type =
         m_ast.GetSymbolFile()->ResolveTypeUID(type_def->getTypeId());
+    if (!target_type)
+      return nullptr;
     std::string name = type_def->getName();
     uint64_t bytes = type_def->getLength();
     if (!target_type)
@@ -179,6 +181,8 @@ lldb::TypeSP PDBASTParser::CreateLLDBTypeFromPDBType(const PDBSymbol &type) {
 
     lldb_private::Type *element_type =
         m_ast.GetSymbolFile()->ResolveTypeUID(element_uid);
+    if (!element_type)
+      return nullptr;
     CompilerType element_ast_type = element_type->GetFullCompilerType();
     CompilerType array_ast_type =
         m_ast.CreateArrayType(element_ast_type, num_elements, false);
diff --git a/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp b/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
index 5e713224fcf8..de9b9f024fc7 100644
--- a/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
+++ b/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp
@@ -19,14 +19,18 @@
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Symbol/SymbolContext.h"
 #include "lldb/Symbol/TypeMap.h"
+#include "lldb/Utility/RegularExpression.h"
 
 #include "llvm/DebugInfo/PDB/GenericError.h"
+#include "llvm/DebugInfo/PDB/IPDBDataStream.h"
 #include "llvm/DebugInfo/PDB/IPDBEnumChildren.h"
 #include "llvm/DebugInfo/PDB/IPDBLineNumber.h"
 #include "llvm/DebugInfo/PDB/IPDBSourceFile.h"
+#include "llvm/DebugInfo/PDB/IPDBTable.h"
 #include "llvm/DebugInfo/PDB/PDBSymbol.h"
 #include "llvm/DebugInfo/PDB/PDBSymbolCompiland.h"
 #include "llvm/DebugInfo/PDB/PDBSymbolCompilandDetails.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolData.h"
 #include "llvm/DebugInfo/PDB/PDBSymbolExe.h"
 #include "llvm/DebugInfo/PDB/PDBSymbolFunc.h"
 #include "llvm/DebugInfo/PDB/PDBSymbolFuncDebugEnd.h"
@@ -93,6 +97,10 @@ SymbolFilePDB::SymbolFilePDB(lldb_private::ObjectFile *object_file)
 SymbolFilePDB::~SymbolFilePDB() {}
 
 uint32_t SymbolFilePDB::CalculateAbilities() {
+  uint32_t abilities = 0;
+  if (!m_obj_file)
+    return 0;
+
   if (!m_session_up) {
     // Lazily load and match the PDB file, but only do this once.
     std::string exePath = m_obj_file->GetFileSpec().GetPath();
@@ -100,10 +108,46 @@ uint32_t SymbolFilePDB::CalculateAbilities() {
                                 m_session_up);
     if (error) {
       llvm::consumeError(std::move(error));
-      return 0;
+      auto module_sp = m_obj_file->GetModule();
+      if (!module_sp)
+        return 0;
+      // See if any symbol file is specified through `--symfile` option.
+      FileSpec symfile = module_sp->GetSymbolFileFileSpec();
+      if (!symfile)
+        return 0;
+      error = loadDataForPDB(PDB_ReaderType::DIA,
+                             llvm::StringRef(symfile.GetPath()),
+                             m_session_up);
+      if (error) {
+        llvm::consumeError(std::move(error));
+        return 0;
+      }
     }
   }
-  return CompileUnits | LineTables;
+  if (!m_session_up.get())
+    return 0;
+
+  auto enum_tables_up = m_session_up->getEnumTables();
+  if (!enum_tables_up)
+    return 0;
+  while (auto table_up = enum_tables_up->getNext()) {
+    if (table_up->getItemCount() == 0)
+      continue;
+    auto type = table_up->getTableType();
+    switch (type) {
+    case PDB_TableType::Symbols:
+      // This table represents a store of symbols with types listed in
+      // PDBSym_Type
+      abilities |= (CompileUnits | Functions | Blocks |
+                    GlobalVariables | LocalVariables | VariableTypes);
+      break;
+    case PDB_TableType::LineNumbers:
+      abilities |= LineTables;
+      break;
+    default: break;
+    }
+  }
+  return abilities;
 }
 
 void SymbolFilePDB::InitializeObject() {
@@ -250,7 +294,8 @@ lldb_private::Type *SymbolFilePDB::ResolveTypeUID(lldb::user_id_t type_uid) {
     return nullptr;
 
   lldb::TypeSP result = pdb->CreateLLDBTypeFromPDBType(*pdb_type);
-  m_types.insert(std::make_pair(type_uid, result));
+  if (result.get())
+    m_types.insert(std::make_pair(type_uid, result));
   return result.get();
 }
 
@@ -385,19 +430,16 @@ uint32_t SymbolFilePDB::FindTypes(
 
   std::string name_str = name.AsCString();
 
-  // If this might be a regex, we have to return EVERY symbol and process them
-  // one by one, which is going to destroy performance on large PDB files.  So
-  // try really hard not to use a regex match.
-  if (name_str.find_first_of("[]?*.-+\\") != std::string::npos)
-    FindTypesByRegex(name_str, max_matches, types);
-  else
-    FindTypesByName(name_str, max_matches, types);
+  // There is an assumption 'name' is not a regex
+  FindTypesByName(name_str, max_matches, types);
+   
   return types.GetSize();
 }
 
-void SymbolFilePDB::FindTypesByRegex(const std::string &regex,
-                                     uint32_t max_matches,
-                                     lldb_private::TypeMap &types) {
+void
+SymbolFilePDB::FindTypesByRegex(const lldb_private::RegularExpression &regex,
+                                uint32_t max_matches,
+                                lldb_private::TypeMap &types) {
   // When searching by regex, we need to go out of our way to limit the search
   // space as much as possible since this searches EVERYTHING in the PDB,
   // manually doing regex comparisons.  PDB library isn't optimized for regex
@@ -409,8 +451,6 @@ void SymbolFilePDB::FindTypesByRegex(const std::string &regex,
   auto global = m_session_up->getGlobalScope();
   std::unique_ptr<IPDBEnumSymbols> results;
 
-  std::regex re(regex);
-
   uint32_t matches = 0;
 
   for (auto tag : tags_to_search) {
@@ -433,7 +473,7 @@ void SymbolFilePDB::FindTypesByRegex(const std::string &regex,
         continue;
       }
 
-      if (!std::regex_match(type_name, re))
+      if (!regex.Execute(type_name))
         continue;
 
       // This should cause the type to get cached and stored in the `m_types`
diff --git a/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h b/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h
index efd2cb081dca..d78358c714ac 100644
--- a/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h
+++ b/source/Plugins/SymbolFile/PDB/SymbolFilePDB.h
@@ -172,7 +172,8 @@ private:
       const llvm::pdb::PDBSymbolCompiland &cu,
       llvm::DenseMap<uint32_t, uint32_t> &index_map) const;
 
-  void FindTypesByRegex(const std::string &regex, uint32_t max_matches,
+  void FindTypesByRegex(const lldb_private::RegularExpression &regex,
+                        uint32_t max_matches,
                         lldb_private::TypeMap &types);
 
   void FindTypesByName(const std::string &name, uint32_t max_matches,
diff --git a/source/Symbol/ObjectFile.cpp b/source/Symbol/ObjectFile.cpp
index 7d73cb19d508..2129a4463cdd 100644
--- a/source/Symbol/ObjectFile.cpp
+++ b/source/Symbol/ObjectFile.cpp
@@ -688,3 +688,8 @@ Status ObjectFile::LoadInMemory(Target &target, bool set_pc) {
 void ObjectFile::RelocateSection(lldb_private::Section *section)
 {
 }
+
+DataBufferSP ObjectFile::MapFileData(const FileSpec &file, uint64_t Size,
+                                     uint64_t Offset) {
+  return DataBufferLLVM::CreateSliceFromPath(file.GetPath(), Size, Offset);
+}
diff --git a/source/Target/Target.cpp b/source/Target/Target.cpp
index 903f50887fec..fdc10cf48275 100644
--- a/source/Target/Target.cpp
+++ b/source/Target/Target.cpp
@@ -2313,7 +2313,7 @@ ExpressionResults Target::EvaluateExpression(
     result_valobj_sp = persistent_var_sp->GetValueObject();
     execution_results = eExpressionCompleted;
   } else {
-    const char *prefix = GetExpressionPrefixContentsAsCString();
+    llvm::StringRef prefix = GetExpressionPrefixContents();
     Status error;
     execution_results = UserExpression::Evaluate(exe_ctx, options, expr, prefix,
                                                  result_valobj_sp, error,
@@ -4046,18 +4046,19 @@ LanguageType TargetProperties::GetLanguage() const {
   return LanguageType();
 }
 
-const char *TargetProperties::GetExpressionPrefixContentsAsCString() {
+llvm::StringRef TargetProperties::GetExpressionPrefixContents() {
   const uint32_t idx = ePropertyExprPrefix;
   OptionValueFileSpec *file =
       m_collection_sp->GetPropertyAtIndexAsOptionValueFileSpec(nullptr, false,
                                                                idx);
   if (file) {
-    const bool null_terminate = true;
-    DataBufferSP data_sp(file->GetFileContents(null_terminate));
+    DataBufferSP data_sp(file->GetFileContents());
     if (data_sp)
-      return (const char *)data_sp->GetBytes();
+      return llvm::StringRef(
+          reinterpret_cast<const char *>(data_sp->GetBytes()),
+          data_sp->GetByteSize());
   }
-  return nullptr;
+  return "";
 }
 
 bool TargetProperties::GetBreakpointsConsultPlatformAvoidList() {
diff --git a/source/Utility/DataBufferLLVM.cpp b/source/Utility/DataBufferLLVM.cpp
index bebcafbf9150..713c3c2814ea 100644
--- a/source/Utility/DataBufferLLVM.cpp
+++ b/source/Utility/DataBufferLLVM.cpp
@@ -18,7 +18,8 @@
 
 using namespace lldb_private;
 
-DataBufferLLVM::DataBufferLLVM(std::unique_ptr<llvm::MemoryBuffer> MemBuffer)
+DataBufferLLVM::DataBufferLLVM(
+    std::unique_ptr<llvm::WritableMemoryBuffer> MemBuffer)
     : Buffer(std::move(MemBuffer)) {
   assert(Buffer != nullptr &&
          "Cannot construct a DataBufferLLVM with a null buffer");
@@ -28,13 +29,13 @@ DataBufferLLVM::~DataBufferLLVM() {}
 
 std::shared_ptr<DataBufferLLVM>
 DataBufferLLVM::CreateSliceFromPath(const llvm::Twine &Path, uint64_t Size,
-                               uint64_t Offset, bool Private) {
+                                    uint64_t Offset) {
   // If the file resides non-locally, pass the volatile flag so that we don't
   // mmap it.
-  if (!Private)
-    Private = !llvm::sys::fs::is_local(Path);
+  bool IsVolatile = !llvm::sys::fs::is_local(Path);
 
-  auto Buffer = llvm::MemoryBuffer::getFileSlice(Path, Size, Offset, Private);
+  auto Buffer =
+      llvm::WritableMemoryBuffer::getFileSlice(Path, Size, Offset, IsVolatile);
   if (!Buffer)
     return nullptr;
   return std::shared_ptr<DataBufferLLVM>(
@@ -42,13 +43,12 @@ DataBufferLLVM::CreateSliceFromPath(const llvm::Twine &Path, uint64_t Size,
 }
 
 std::shared_ptr<DataBufferLLVM>
-DataBufferLLVM::CreateFromPath(const llvm::Twine &Path, bool NullTerminate, bool Private) {
+DataBufferLLVM::CreateFromPath(const llvm::Twine &Path) {
   // If the file resides non-locally, pass the volatile flag so that we don't
   // mmap it.
-  if (!Private)
-    Private = !llvm::sys::fs::is_local(Path);
+  bool IsVolatile = !llvm::sys::fs::is_local(Path);
 
-  auto Buffer = llvm::MemoryBuffer::getFile(Path, -1, NullTerminate, Private);
+  auto Buffer = llvm::WritableMemoryBuffer::getFile(Path, -1, IsVolatile);
   if (!Buffer)
     return nullptr;
   return std::shared_ptr<DataBufferLLVM>(
@@ -56,15 +56,13 @@ DataBufferLLVM::CreateFromPath(const llvm::Twine &Path, bool NullTerminate, bool
 }
 
 uint8_t *DataBufferLLVM::GetBytes() {
-  return const_cast<uint8_t *>(GetBuffer());
+  return reinterpret_cast<uint8_t *>(Buffer->getBufferStart());
 }
 
-const uint8_t *DataBufferLLVM::GetBytes() const { return GetBuffer(); }
+const uint8_t *DataBufferLLVM::GetBytes() const {
+  return reinterpret_cast<const uint8_t *>(Buffer->getBufferStart());
+}
 
 lldb::offset_t DataBufferLLVM::GetByteSize() const {
   return Buffer->getBufferSize();
 }
-
-const uint8_t *DataBufferLLVM::GetBuffer() const {
-  return reinterpret_cast<const uint8_t *>(Buffer->getBufferStart());
-}
diff --git a/tools/debugserver/debugserver.xcodeproj/project.pbxproj b/tools/debugserver/debugserver.xcodeproj/project.pbxproj
index d97b438ce8e5..6a919cfef5de 100644
--- a/tools/debugserver/debugserver.xcodeproj/project.pbxproj
+++ b/tools/debugserver/debugserver.xcodeproj/project.pbxproj
@@ -820,7 +820,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "-";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "-";
@@ -920,8 +920,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
@@ -1020,8 +1019,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
@@ -1127,8 +1125,7 @@
 				CLANG_WARN_INT_CONVERSION = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				CODE_SIGN_IDENTITY = "";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
@@ -1209,8 +1206,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
@@ -1279,8 +1275,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
@@ -1352,7 +1347,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "-";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "-";
@@ -1460,8 +1455,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
@@ -1601,8 +1595,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
@@ -1699,8 +1692,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
@@ -1823,8 +1815,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
@@ -1955,8 +1946,7 @@
 			buildSettings = {
 				CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
 				CLANG_CXX_LIBRARY = "libc++";
-				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-macosx-entitlements.plist";
-				"CODE_SIGN_ENTITLEMENTS[sdk=iphoneos*]" = "source/debugserver-entitlements.plist";
+				"CODE_SIGN_ENTITLEMENTS[sdk=*]" = "source/debugserver-entitlements.plist";
 				"CODE_SIGN_ENTITLEMENTS[sdk=macosx*]" = "source/debugserver-macosx-entitlements.plist";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
 				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "";
diff --git a/tools/debugserver/source/RNBContext.cpp b/tools/debugserver/source/RNBContext.cpp
index c1319af02322..c86511c6e226 100644
--- a/tools/debugserver/source/RNBContext.cpp
+++ b/tools/debugserver/source/RNBContext.cpp
@@ -42,6 +42,25 @@ const char *RNBContext::EnvironmentAtIndex(size_t index) {
     return NULL;
 }
 
+static std::string GetEnvironmentKey(const std::string &env) {
+  std::string key = env.substr(0, env.find('='));
+  if (!key.empty() && key.back() == '=')
+    key.pop_back();
+  return key;
+}
+
+void RNBContext::PushEnvironmentIfNeeded(const char *arg) {
+  if (!arg)
+    return;
+  std::string arg_key = GetEnvironmentKey(arg);
+
+  for (const std::string &entry: m_env_vec) {
+    if (arg_key == GetEnvironmentKey(entry))
+      return;
+  }
+  m_env_vec.push_back(arg);
+}
+
 const char *RNBContext::ArgumentAtIndex(size_t index) {
   if (index < m_arg_vec.size())
     return m_arg_vec[index].c_str();
diff --git a/tools/debugserver/source/RNBContext.h b/tools/debugserver/source/RNBContext.h
index 6fe7a299573a..0c649ae41007 100644
--- a/tools/debugserver/source/RNBContext.h
+++ b/tools/debugserver/source/RNBContext.h
@@ -86,6 +86,7 @@ public:
     if (arg)
       m_env_vec.push_back(arg);
   }
+  void PushEnvironmentIfNeeded(const char *arg);
   void ClearEnvironment() {
     m_env_vec.erase(m_env_vec.begin(), m_env_vec.end());
   }
diff --git a/tools/debugserver/source/debugserver.cpp b/tools/debugserver/source/debugserver.cpp
index 8291f8d32b51..7ae321ba431b 100644
--- a/tools/debugserver/source/debugserver.cpp
+++ b/tools/debugserver/source/debugserver.cpp
@@ -1020,6 +1020,7 @@ int main(int argc, char *argv[]) {
   optind = 1;
 #endif
 
+  bool forward_env = false;
   while ((ch = getopt_long_only(argc, argv, short_options, g_long_options,
                                 &long_option_index)) != -1) {
     DNBLogDebug("option: ch == %c (0x%2.2x) --%s%c%s\n", ch, (uint8_t)ch,
@@ -1251,14 +1252,7 @@ int main(int argc, char *argv[]) {
       break;
 
     case 'F':
-      // Pass the current environment down to the process that gets launched
-      {
-        char **host_env = *_NSGetEnviron();
-        char *env_entry;
-        size_t i;
-        for (i = 0; (env_entry = host_env[i]) != NULL; ++i)
-          remote->Context().PushEnvironment(env_entry);
-      }
+      forward_env = true;
       break;
 
     case '2':
@@ -1420,6 +1414,18 @@ int main(int argc, char *argv[]) {
   if (start_mode == eRNBRunLoopModeExit)
     return -1;
 
+  if (forward_env || start_mode == eRNBRunLoopModeInferiorLaunching) {
+    // Pass the current environment down to the process that gets launched
+    // This happens automatically in the "launching" mode. For the rest, we
+    // only do that if the user explicitly requested this via --forward-env
+    // argument.
+    char **host_env = *_NSGetEnviron();
+    char *env_entry;
+    size_t i;
+    for (i = 0; (env_entry = host_env[i]) != NULL; ++i)
+      remote->Context().PushEnvironmentIfNeeded(env_entry);
+  }
+
   RNBRunLoopMode mode = start_mode;
   char err_str[1024] = {'\0'};
 
diff --git a/tools/lldb-mi/MICmnLLDBDebuggerHandleEvents.cpp b/tools/lldb-mi/MICmnLLDBDebuggerHandleEvents.cpp
index 561fa91a0ee3..dceb29f5908f 100644
--- a/tools/lldb-mi/MICmnLLDBDebuggerHandleEvents.cpp
+++ b/tools/lldb-mi/MICmnLLDBDebuggerHandleEvents.cpp
@@ -18,6 +18,7 @@
 #include "lldb/API/SBTarget.h"
 #include "lldb/API/SBThread.h"
 #include "lldb/API/SBUnixSignals.h"
+#include "llvm/Support/Compiler.h"
 #ifdef _WIN32
 #include <io.h> // For the ::_access()
 #else
@@ -899,6 +900,7 @@ bool CMICmnLLDBDebuggerHandleEvents::HandleProcessEventBroadcastBitStateChanged(
     bOk = HandleProcessEventStateStopped(vEvent, bShouldBrk);
     if (bShouldBrk)
       break;
+    LLVM_FALLTHROUGH;
   case lldb::eStateCrashed:
   case lldb::eStateSuspended:
     pEventType = "eStateSuspended";
diff --git a/tools/lldb-mi/MIUtilString.cpp b/tools/lldb-mi/MIUtilString.cpp
index 45196a70398d..3797d1001798 100644
--- a/tools/lldb-mi/MIUtilString.cpp
+++ b/tools/lldb-mi/MIUtilString.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 // Third party headers
+#include "llvm/Support/Compiler.h"
 #include <cstdlib>
 #include <inttypes.h> // for PRIx8
 #include <limits.h>   // for ULONG_MAX
@@ -890,7 +891,7 @@ CMIUtilString CMIUtilString::ConvertToPrintableASCII(const char vChar,
   case '"':
     if (bEscapeQuotes)
       return "\\\"";
-  // fall thru
+    LLVM_FALLTHROUGH;
   default:
     if (::isprint(vChar))
       return Format("%c", vChar);
@@ -924,7 +925,7 @@ CMIUtilString::ConvertCharValueToPrintableASCII(char vChar,
   case '"':
     if (bEscapeQuotes)
       return "\\\"";
-  // fall thru
+    LLVM_FALLTHROUGH;
   default:
     if (::isprint(vChar))
       return Format("%c", vChar);
diff --git a/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp b/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp
index 1e9cf1700642..ac4eba1197ab 100644
--- a/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp
+++ b/unittests/SymbolFile/PDB/SymbolFilePDBTests.cpp
@@ -154,8 +154,7 @@ TEST_F(SymbolFilePDBTests, TestAbilitiesForPDB) {
   EXPECT_NE(nullptr, symfile);
   EXPECT_EQ(symfile->GetPluginName(), SymbolFilePDB::GetPluginNameStatic());
 
-  uint32_t expected_abilities =
-      SymbolFile::CompileUnits | SymbolFile::LineTables;
+  uint32_t expected_abilities = SymbolFile::kAllAbilities;
   EXPECT_EQ(expected_abilities, symfile->CalculateAbilities());
 }
 
@@ -520,6 +519,13 @@ TEST_F(SymbolFilePDBTests, TestRegexNameMatch) {
                                             false, 0, searched_files, results);
   EXPECT_GT(num_results, 1u);
   EXPECT_EQ(num_results, results.GetSize());
+
+  // We expect no exception thrown if the given regex can't be compiled
+  results.Clear();
+  num_results = symfile->FindTypes(sc, ConstString("**"), nullptr,
+                                   false, 0, searched_files, results);
+  EXPECT_EQ(num_results, 0u);
+  EXPECT_EQ(num_results, results.GetSize());
 }
 
 TEST_F(SymbolFilePDBTests, TestMaxMatches) {
diff --git a/unittests/tools/lldb-server/CMakeLists.txt b/unittests/tools/lldb-server/CMakeLists.txt
index 8641e8ddb5c9..14df6e64b2ac 100644
--- a/unittests/tools/lldb-server/CMakeLists.txt
+++ b/unittests/tools/lldb-server/CMakeLists.txt
@@ -13,9 +13,9 @@ add_lldb_test_executable(thread_inferior inferior/thread_inferior.cpp)
 add_lldb_test_executable(environment_check inferior/environment_check.cpp)
 
 if (CMAKE_SYSTEM_NAME MATCHES "Darwin")
-  add_definitions(-DLLDB_SERVER="$<TARGET_FILE:debugserver>")
+  add_definitions(-DLLDB_SERVER="$<TARGET_FILE:debugserver>" -DLLDB_SERVER_IS_DEBUGSERVER=1)
 else()
-  add_definitions(-DLLDB_SERVER="$<TARGET_FILE:lldb-server>")
+  add_definitions(-DLLDB_SERVER="$<TARGET_FILE:lldb-server>" -DLLDB_SERVER_IS_DEBUGSERVER=0)
 endif()
 
 add_definitions(
diff --git a/unittests/tools/lldb-server/tests/LLGSTest.cpp b/unittests/tools/lldb-server/tests/LLGSTest.cpp
index 75d964ed26f4..8733adefa389 100644
--- a/unittests/tools/lldb-server/tests/LLGSTest.cpp
+++ b/unittests/tools/lldb-server/tests/LLGSTest.cpp
@@ -16,11 +16,6 @@ using namespace lldb_private;
 using namespace llvm;
 
 TEST_F(TestBase, LaunchModePreservesEnvironment) {
-  if (TestClient::IsDebugServer()) {
-    GTEST_LOG_(WARNING) << "Test fails with debugserver: llvm.org/pr35671";
-    return;
-  }
-
   putenv(const_cast<char *>("LLDB_TEST_MAGIC_VARIABLE=LLDB_TEST_MAGIC_VALUE"));
 
   auto ClientOr = TestClient::launch(getLogFileName(),
@@ -34,3 +29,20 @@ TEST_F(TestBase, LaunchModePreservesEnvironment) {
       HasValue(testing::Property(&StopReply::getKind,
                                  WaitStatus{WaitStatus::Exit, 0})));
 }
+
+TEST_F(TestBase, DS_TEST(DebugserverEnv)) {
+  // Test that --env takes precedence over inherited environment variables.
+  putenv(const_cast<char *>("LLDB_TEST_MAGIC_VARIABLE=foobar"));
+
+  auto ClientOr = TestClient::launchCustom(getLogFileName(),
+      { "--env", "LLDB_TEST_MAGIC_VARIABLE=LLDB_TEST_MAGIC_VALUE" },
+                                     {getInferiorPath("environment_check")});
+  ASSERT_THAT_EXPECTED(ClientOr, Succeeded());
+  auto &Client = **ClientOr;
+
+  ASSERT_THAT_ERROR(Client.ContinueAll(), Succeeded());
+  ASSERT_THAT_EXPECTED(
+      Client.GetLatestStopReplyAs<StopReplyExit>(),
+      HasValue(testing::Property(&StopReply::getKind,
+                                 WaitStatus{WaitStatus::Exit, 0})));
+}
diff --git a/unittests/tools/lldb-server/tests/TestClient.cpp b/unittests/tools/lldb-server/tests/TestClient.cpp
index 773466abe855..4653c2df1ce9 100644
--- a/unittests/tools/lldb-server/tests/TestClient.cpp
+++ b/unittests/tools/lldb-server/tests/TestClient.cpp
@@ -27,11 +27,6 @@ using namespace lldb_private;
 using namespace llvm;
 
 namespace llgs_tests {
-bool TestClient::IsDebugServer() {
-  return sys::path::filename(LLDB_SERVER).contains("debugserver");
-}
-
-bool TestClient::IsLldbServer() { return !IsDebugServer(); }
 
 TestClient::TestClient(std::unique_ptr<Connection> Conn) {
   SetConnection(Conn.release());
@@ -56,6 +51,10 @@ Expected<std::unique_ptr<TestClient>> TestClient::launch(StringRef Log) {
 }
 
 Expected<std::unique_ptr<TestClient>> TestClient::launch(StringRef Log, ArrayRef<StringRef> InferiorArgs) {
+  return launchCustom(Log, {}, InferiorArgs);
+}
+
+Expected<std::unique_ptr<TestClient>> TestClient::launchCustom(StringRef Log, ArrayRef<StringRef> ServerArgs, ArrayRef<StringRef> InferiorArgs) {
   const ArchSpec &arch_spec = HostInfo::GetArchitecture();
   Args args;
   args.AppendArgument(LLDB_SERVER);
@@ -80,6 +79,9 @@ Expected<std::unique_ptr<TestClient>> TestClient::launch(StringRef Log, ArrayRef
   args.AppendArgument(
       ("localhost:" + Twine(listen_socket.GetLocalPortNumber())).str());
 
+  for (StringRef arg : ServerArgs)
+    args.AppendArgument(arg);
+
   if (!InferiorArgs.empty()) {
     args.AppendArgument("--");
     for (StringRef arg : InferiorArgs)
diff --git a/unittests/tools/lldb-server/tests/TestClient.h b/unittests/tools/lldb-server/tests/TestClient.h
index 4fa1bbb8ac93..b5195307876d 100644
--- a/unittests/tools/lldb-server/tests/TestClient.h
+++ b/unittests/tools/lldb-server/tests/TestClient.h
@@ -21,12 +21,20 @@
 #include <memory>
 #include <string>
 
+#if LLDB_SERVER_IS_DEBUGSERVER
+#define LLGS_TEST(x) DISABLED_ ## x
+#define DS_TEST(x) x
+#else
+#define LLGS_TEST(x) x
+#define DS_TEST(x) DISABLED_ ## x
+#endif
+
 namespace llgs_tests {
 class TestClient
     : public lldb_private::process_gdb_remote::GDBRemoteCommunicationClient {
 public:
-  static bool IsDebugServer();
-  static bool IsLldbServer();
+  static bool IsDebugServer() { return LLDB_SERVER_IS_DEBUGSERVER; }
+  static bool IsLldbServer() { return !IsDebugServer(); }
 
   /// Launches the server, connects it to the client and returns the client. If
   /// Log is non-empty, the server will write it's log to this file.
@@ -37,6 +45,13 @@ public:
   static llvm::Expected<std::unique_ptr<TestClient>>
   launch(llvm::StringRef Log, llvm::ArrayRef<llvm::StringRef> InferiorArgs);
 
+  /// Allows user to pass additional arguments to the server. Be careful when
+  /// using this for generic tests, as the two stubs have different
+  /// command-line interfaces.
+  static llvm::Expected<std::unique_ptr<TestClient>>
+  launchCustom(llvm::StringRef Log, llvm::ArrayRef<llvm::StringRef> ServerArgs, llvm::ArrayRef<llvm::StringRef> InferiorArgs);
+
+
   ~TestClient() override;
   llvm::Error SetInferior(llvm::ArrayRef<std::string> inferior_args);
   llvm::Error ListThreadsInStopReply();