Index: llvm/test/tools/llvm-objdump/X86/debug-vars.yaml
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-objdump/X86/debug-vars.yaml
@@ -0,0 +1,22 @@
+## Test parsing of --dwarf=frames
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %S/disassemble-print-comments.s -o %t 
+
+# RUN: llvm-objdump -d --no-show-raw-insn --debug-vars  %t | FileCheck %s --check-prefix=UNICODE
+# RUN: llvm-objdump -d --no-show-raw-insn --debug-vars=unicode  %t | FileCheck %s --check-prefix=UNICODE
+
+# UNICODE:     0000000000000000 <foo>:
+# UNICODE-NEXT:                                                                    ┠─ bar = RDX
+# UNICODE-NEXT:       0:       nop                                                 ┃
+# UNICODE-NEXT:       1:       cmpl    $305419896, %eax        # imm = 0x12345678  ┻
+
+# RUN: llvm-objdump -d --no-show-raw-insn --debug-vars=ascii  %t | FileCheck %s --check-prefix=ASCII
+
+# ASCII:     0000000000000000 <foo>:
+# ASCII-NEXT:                                                                    |- bar = RDX
+# ASCII-NEXT:       0:       nop                                                 |
+# ASCII-NEXT:       1:       cmpl    $305419896, %eax        # imm = 0x12345678  v
+
+# RUN: not llvm-objdump -d --no-show-raw-insn --debug-vars=bad_value %t 2>&1 | FileCheck %s --check-prefix=ERROR
+
+# ERROR: error: 'bad_value' is not a valid value for '--debug-vars='
Index: llvm/test/tools/llvm-objdump/X86/eh_frame.yaml
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-objdump/X86/eh_frame.yaml
@@ -0,0 +1,17 @@
+## Test parsing of --dwarf=frames
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-objdump --dwarf=frames %t | FileCheck %s
+# CHECK: .debug_frame contents:
+# CHECK: .eh_frame contents:
+
+# RUN: not llvm-objdump --dwarf=bad_value %t 2>&1 | FileCheck %s --check-prefix=ERROR
+
+# ERROR: error: 'bad_value' is not a valid value for '--dwarf='
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64
Index: llvm/tools/llvm-objdump/llvm-objdump.h
===================================================================
--- llvm/tools/llvm-objdump/llvm-objdump.h
+++ llvm/tools/llvm-objdump/llvm-objdump.h
@@ -35,6 +35,7 @@
   DVDisabled,
   DVUnicode,
   DVASCII,
+  DVInvalid
 };
 
 extern bool ArchiveHeaders;
Index: llvm/tools/llvm-objdump/llvm-objdump.cpp
===================================================================
--- llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -2500,6 +2500,11 @@
   }
 }
 
+static void invalidArgValue(const opt::Arg *A) {
+  reportCmdLineError("'" + StringRef(A->getValue()) +
+                     "' is not a valid value for '" + A->getSpelling() + "'");
+}
+
 static std::vector<std::string>
 commaSeparatedValues(const llvm::opt::InputArgList &InputArgs, int ID) {
   std::vector<std::string> Values;
@@ -2573,8 +2578,11 @@
       commaSeparatedValues(InputArgs, OBJDUMP_disassemble_symbols_EQ);
   DisassembleZeroes = InputArgs.hasArg(OBJDUMP_disassemble_zeroes);
   if (const opt::Arg *A = InputArgs.getLastArg(OBJDUMP_dwarf_EQ)) {
-    DwarfDumpType =
-        StringSwitch<DIDumpType>(A->getValue()).Case("frames", DIDT_DebugFrame);
+    DwarfDumpType = StringSwitch<DIDumpType>(A->getValue())
+                        .Case("frames", DIDT_DebugFrame)
+                        .Default(DIDT_Null);
+    if (DwarfDumpType == DIDT_Null)
+      invalidArgValue(A);
   }
   DynamicRelocations = InputArgs.hasArg(OBJDUMP_dynamic_reloc);
   FaultMapSection = InputArgs.hasArg(OBJDUMP_fault_map_section);
@@ -2611,7 +2619,10 @@
   if (const opt::Arg *A = InputArgs.getLastArg(OBJDUMP_debug_vars_EQ)) {
     DbgVariables = StringSwitch<DebugVarsFormat>(A->getValue())
                        .Case("ascii", DVASCII)
-                       .Case("unicode", DVUnicode);
+                       .Case("unicode", DVUnicode)
+                       .Default(DVInvalid);
+    if (DbgVariables == DVInvalid)
+      invalidArgValue(A);
   }
   parseIntArg(InputArgs, OBJDUMP_debug_vars_indent_EQ, DbgIndent);