Index: include/lldb/Symbol/DWARFCallFrameInfo.h
===================================================================
--- include/lldb/Symbol/DWARFCallFrameInfo.h
+++ include/lldb/Symbol/DWARFCallFrameInfo.h
@@ -37,7 +37,7 @@
   DWARFCallFrameInfo(ObjectFile &objfile, lldb::SectionSP &section,
                      lldb::RegisterKind reg_kind, bool is_eh_frame);
 
-  ~DWARFCallFrameInfo();
+  ~DWARFCallFrameInfo() = default;
 
   // Locate an AddressRange that includes the provided Address in this
   // object's eh_frame/debug_info
@@ -74,6 +74,11 @@
 
 private:
   enum { CFI_AUG_MAX_SIZE = 8, CFI_HEADER_SIZE = 8 };
+  enum CFIVersion {
+    CFI_VERSION1 = 1, // DWARF v.2
+    CFI_VERSION3 = 3, // DWARF v.3
+    CFI_VERSION4 = 4  // DWARF v.4, v.5
+  };
 
   struct CIE {
     dw_offset_t cie_offset;
@@ -80,6 +85,9 @@
     uint8_t version;
     char augmentation[CFI_AUG_MAX_SIZE]; // This is typically empty or very
                                          // short.
+    uint8_t address_size = sizeof(uint32_t); // The size of a target address.
+    uint8_t segment_size = 0;                // The size of a segment selector.
+
     uint32_t code_align;
     int32_t data_align;
     uint32_t return_addr_reg_num;
Index: source/Symbol/DWARFCallFrameInfo.cpp
===================================================================
--- source/Symbol/DWARFCallFrameInfo.cpp
+++ source/Symbol/DWARFCallFrameInfo.cpp
@@ -161,8 +161,6 @@
       m_fde_index(), m_fde_index_initialized(false),
       m_is_eh_frame(is_eh_frame) {}
 
-DWARFCallFrameInfo::~DWARFCallFrameInfo() {}
-
 bool DWARFCallFrameInfo::GetUnwindPlan(Address addr, UnwindPlan &unwind_plan) {
   FDEEntryMap::Entry fde_entry;
 
@@ -276,6 +274,12 @@
     //    cie.cieID = cieID;
     cie_sp->ptr_encoding = DW_EH_PE_absptr; // default
     cie_sp->version = m_cfi_data.GetU8(&offset);
+    if (cie_sp->version > CFI_VERSION4) {
+      Host::SystemLog(Host::eSystemLogError,
+                      "CIE parse error: CFI version %d is not supported\n",
+                      cie_sp->version);
+      return nullptr;
+    }
 
     for (i = 0; i < CFI_AUG_MAX_SIZE; ++i) {
       cie_sp->augmentation[i] = m_cfi_data.GetU8(&offset);
@@ -294,12 +298,24 @@
                       "CIE parse error: CIE augmentation string was too large "
                       "for the fixed sized buffer of %d bytes.\n",
                       CFI_AUG_MAX_SIZE);
-      return cie_sp;
+      return nullptr;
     }
+
+    // m_cfi_data uses address size from target architecture of the process
+    // may ignore these fields?
+    if (!m_is_eh_frame && cie_sp->version >= CFI_VERSION4) {
+      cie_sp->address_size = m_cfi_data.GetU8(&offset);
+      cie_sp->segment_size = m_cfi_data.GetU8(&offset);
+    }
+
     cie_sp->code_align = (uint32_t)m_cfi_data.GetULEB128(&offset);
     cie_sp->data_align = (int32_t)m_cfi_data.GetSLEB128(&offset);
-    cie_sp->return_addr_reg_num = m_cfi_data.GetU8(&offset);
 
+    cie_sp->return_addr_reg_num =
+        !m_is_eh_frame && cie_sp->version >= CFI_VERSION3
+            ? static_cast<uint32_t>(m_cfi_data.GetULEB128(&offset))
+            : m_cfi_data.GetU8(&offset);
+
     if (cie_sp->augmentation[0]) {
       // Get the length of the eh_frame augmentation data
       // which starts with a ULEB128 length in bytes
@@ -461,11 +477,33 @@
       m_fde_index_initialized = true;
       return;
     }
+
+    // An FDE entry contains CIE_pointer in debug_frame in same place as cie_id
+    // in eh_frame. CIE_pointer is an offset into the .debug_frame section.
+    // So, variable cie_offset should be equal to cie_id for debug_frame.
+    // FDE entries with cie_id == 0 shouldn't be ignored for it.
+    if ((cie_id == 0 && m_is_eh_frame) || cie_id == UINT32_MAX || len == 0) {
+      auto cie_sp = ParseCIE(current_entry);
+      if (!cie_sp) {
+        // Cannot parse, the reason is already logged
+        m_fde_index.Clear();
+        m_fde_index_initialized = true;
+        return;
+      }
+
+      m_cie_map[current_entry] = std::move(cie_sp);
+      offset = next_entry;
+      continue;
+    }
+
+    if (!m_is_eh_frame)
+      cie_offset = cie_id;
+
     if (cie_offset > m_cfi_data.GetByteSize()) {
-      Host::SystemLog(
-          Host::eSystemLogError,
-          "error: Invalid cie offset of 0x%x found in cie/fde at 0x%x\n",
-          cie_offset, current_entry);
+      Host::SystemLog(Host::eSystemLogError,
+                      "error: Invalid cie offset of 0x%x "
+                      "found in cie/fde at 0x%x\n",
+                      cie_offset, current_entry);
       // Don't trust anything in this eh_frame section if we find blatantly
       // invalid data.
       m_fde_index.Clear();
@@ -473,12 +511,6 @@
       return;
     }
 
-    if (cie_id == 0 || cie_id == UINT32_MAX || len == 0) {
-      m_cie_map[current_entry] = ParseCIE(current_entry);
-      offset = next_entry;
-      continue;
-    }
-
     const CIE *cie = GetCIE(cie_offset);
     if (cie) {
       const lldb::addr_t pc_rel_addr = m_section_sp->GetFileAddress();
@@ -531,7 +563,8 @@
     cie_offset = m_cfi_data.GetU32(&offset);
   }
 
-  assert(cie_offset != 0 && cie_offset != UINT32_MAX);
+  // FDE entries with zeroth cie_offset may occur for debug_frame.
+  assert(!(m_is_eh_frame && 0 == cie_offset) && cie_offset != UINT32_MAX);
 
   // Translate the CIE_id from the eh_frame format, which
   // is relative to the FDE offset, into a __eh_frame section
Index: source/Symbol/UnwindTable.cpp
===================================================================
--- source/Symbol/UnwindTable.cpp
+++ source/Symbol/UnwindTable.cpp
@@ -51,6 +51,13 @@
     if (sect.get()) {
       m_eh_frame_up.reset(new DWARFCallFrameInfo(m_object_file, sect,
                                                  eRegisterKindEHFrame, true));
+    } else {
+      // Try to find .debug_frame section even if .eh_frame doesn't exist.
+      sect = sl->FindSectionByType(eSectionTypeDWARFDebugFrame, true);
+      if (sect) {
+        m_eh_frame_up.reset(new DWARFCallFrameInfo(m_object_file, sect,
+                                                   eRegisterKindDWARF, false));
+      }
     }
     sect = sl->FindSectionByType(eSectionTypeCompactUnwind, true);
     if (sect.get()) {