Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -960,7 +960,7 @@
   PosFlag<SetTrue, [CC1Option], "Use 32-bit pointers for accessing const/local/shared address spaces">,
   NegFlag<SetFalse>>;
 def fgpu_default_stream_EQ : Joined<["-"], "fgpu-default-stream=">,
-  HelpText<"Specify default stream. Valid values are 'legacy' and 'per-thread'. The default value is 'legacy'. (HIP only)">,
+  HelpText<"Specify default stream. The default value is 'legacy'. (HIP only)">,
   Flags<[CC1Option]>,
   Values<"legacy,per-thread">,
   NormalizedValuesScope<"LangOptions::GPUDefaultStreamKind">,
@@ -1171,7 +1171,7 @@
   MarshallingInfoStringVector<CodeGenOpts<"OffloadObjects">>;
 def fembed_bitcode_EQ : Joined<["-"], "fembed-bitcode=">,
     Group<f_Group>, Flags<[NoXarchOption, CC1Option, CC1AsOption]>, MetaVarName<"<option>">,
-    HelpText<"Embed LLVM bitcode (option: off, all, bitcode, marker)">,
+    HelpText<"Embed LLVM bitcode">,
     Values<"off,all,bitcode,marker">, NormalizedValuesScope<"CodeGenOptions">,
     NormalizedValues<["Embed_Off", "Embed_All", "Embed_Bitcode", "Embed_Marker"]>,
     MarshallingInfoEnum<CodeGenOpts<"EmbedBitcode">, "Embed_Off">;
@@ -1297,7 +1297,7 @@
     ShouldParseIf<!strconcat(fprofile_arcs.KeyPath, "||", ftest_coverage.KeyPath)>;
 def fprofile_update_EQ : Joined<["-"], "fprofile-update=">,
     Group<f_Group>, Flags<[CC1Option, CoreOption]>, Values<"atomic,prefer-atomic,single">,
-    MetaVarName<"<method>">, HelpText<"Set update method of profile counters (atomic,prefer-atomic,single)">,
+    MetaVarName<"<method>">, HelpText<"Set update method of profile counters">,
     MarshallingInfoFlag<CodeGenOpts<"AtomicProfileUpdate">>;
 defm pseudo_probe_for_profiling : BoolFOption<"pseudo-probe-for-profiling",
   CodeGenOpts<"PseudoProbeForProfiling">, DefaultFalse,
@@ -1312,7 +1312,7 @@
     MarshallingInfoStringVector<LangOpts<"ProfileListFiles">>;
 def fswift_async_fp_EQ : Joined<["-"], "fswift-async-fp=">,
     Group<f_Group>, Flags<[CC1Option, CC1AsOption, CoreOption]>, MetaVarName<"<option>">,
-    HelpText<"Control emission of Swift async extended frame info (option: auto, always, never)">,
+    HelpText<"Control emission of Swift async extended frame info">,
     Values<"auto,always,never">,
     NormalizedValuesScope<"CodeGenOptions::SwiftAsyncFramePointerKind">,
     NormalizedValues<["Auto", "Always", "Never"]>,
@@ -1483,7 +1483,7 @@
 def fwasm_exceptions : Flag<["-"], "fwasm-exceptions">, Group<f_Group>,
   HelpText<"Use WebAssembly style exceptions">;
 def exception_model : Separate<["-"], "exception-model">,
-  Flags<[CC1Option, NoDriverOption]>, HelpText<"The exception model: dwarf|sjlj|seh|wasm">,
+  Flags<[CC1Option, NoDriverOption]>, HelpText<"The exception model">,
   Values<"dwarf,sjlj,seh,wasm">,
   NormalizedValuesScope<"LangOptions::ExceptionHandlingKind">,
   NormalizedValues<["DwarfCFI", "SjLj", "WinEH", "Wasm"]>,
@@ -1665,7 +1665,7 @@
   : Joined<["-"], "fsanitize-address-use-after-return=">,
     MetaVarName<"<mode>">,
     Flags<[CC1Option]>,
-    HelpText<"Select the mode of detecting stack use-after-return in AddressSanitizer: never | runtime (default) | always">,
+    HelpText<"Select the mode of detecting stack use-after-return in AddressSanitizer">,
     Group<f_clang_Group>,
     Values<"never,runtime,always">,
     NormalizedValuesScope<"llvm::AsanDetectStackUseAfterReturnMode">,
@@ -1954,7 +1954,7 @@
   HelpText<"Instrument function entry only, after inlining, without arguments to the instrumentation call">,
   MarshallingInfoFlag<CodeGenOpts<"InstrumentFunctionEntryBare">>;
 def fcf_protection_EQ : Joined<["-"], "fcf-protection=">, Flags<[CoreOption, CC1Option]>, Group<f_Group>,
-  HelpText<"Instrument control-flow architecture protection. Options: return, branch, full, none.">, Values<"return,branch,full,none">;
+  HelpText<"Instrument control-flow architecture protection">, Values<"return,branch,full,none">;
 def fcf_protection : Flag<["-"], "fcf-protection">, Group<f_Group>, Flags<[CoreOption, CC1Option]>,
   Alias<fcf_protection_EQ>, AliasArgs<["full"]>,
   HelpText<"Enable cf-protection in 'full' mode">;
@@ -2079,7 +2079,7 @@
 def fapple_link_rtlib : Flag<["-"], "fapple-link-rtlib">, Group<f_Group>,
   HelpText<"Force linking the clang builtins runtime library">;
 def flto_EQ : Joined<["-"], "flto=">, Flags<[CoreOption, CC1Option]>, Group<f_Group>,
-  HelpText<"Set LTO mode to either 'full' or 'thin'">, Values<"thin,full">;
+  HelpText<"Set LTO mode">, Values<"thin,full">;
 def flto_EQ_jobserver : Flag<["-"], "flto=jobserver">, Group<f_Group>,
   Alias<flto_EQ>, AliasArgs<["full"]>, HelpText<"Enable LTO in 'full' mode">;
 def flto_EQ_auto : Flag<["-"], "flto=auto">, Group<f_Group>,
@@ -2089,7 +2089,7 @@
 def fno_lto : Flag<["-"], "fno-lto">, Flags<[CoreOption, CC1Option]>, Group<f_Group>,
   HelpText<"Disable LTO mode (default)">;
 def foffload_lto_EQ : Joined<["-"], "foffload-lto=">, Flags<[CoreOption]>, Group<f_Group>,
-  HelpText<"Set LTO mode to either 'full' or 'thin' for offload compilation">, Values<"thin,full">;
+  HelpText<"Set LTO mode for offload compilation">, Values<"thin,full">;
 def foffload_lto : Flag<["-"], "foffload-lto">, Flags<[CoreOption]>, Group<f_Group>,
   Alias<foffload_lto_EQ>, AliasArgs<["full"]>, HelpText<"Enable LTO in 'full' mode for offload compilation">;
 def fno_offload_lto : Flag<["-"], "fno-offload-lto">, Flags<[CoreOption]>, Group<f_Group>,
@@ -2607,8 +2607,8 @@
 def fno_short_wchar : Flag<["-"], "fno-short-wchar">, Group<f_Group>,
   HelpText<"Force wchar_t to be an unsigned int">;
 def fshow_overloads_EQ : Joined<["-"], "fshow-overloads=">, Group<f_Group>, Flags<[CC1Option]>,
-  HelpText<"Which overload candidates to show when overload resolution fails: "
-           "best|all; defaults to all">, Values<"best,all">,
+  HelpText<"Which overload candidates to show when overload resolution fails. Defaults to all">,
+  Values<"best,all">,
   NormalizedValues<["Ovl_Best", "Ovl_All"]>,
   MarshallingInfoEnum<DiagnosticOpts<"ShowOverloads">, "Ovl_All">;
 defm show_column : BoolFOption<"show-column",
@@ -2655,8 +2655,8 @@
            "overwrite the guard value before overwriting the function's return "
            "address. The reference stack guard value is stored in a global variable.">;
 def ftrivial_auto_var_init : Joined<["-"], "ftrivial-auto-var-init=">, Group<f_Group>,
-  Flags<[CC1Option, CoreOption]>, HelpText<"Initialize trivial automatic stack variables: uninitialized (default)"
-  " | pattern">, Values<"uninitialized,zero,pattern">,
+  Flags<[CC1Option, CoreOption]>, HelpText<"Initialize trivial automatic stack variables. Defaults to 'uninitialized'">,
+  Values<"uninitialized,zero,pattern">,
   NormalizedValuesScope<"LangOptions::TrivialAutoVarInitKind">,
   NormalizedValues<["Uninitialized", "Zero", "Pattern"]>,
   MarshallingInfoEnum<LangOpts<"TrivialAutoVarInit">, "Uninitialized">;
@@ -2751,8 +2751,8 @@
 def ftime_report_EQ: Joined<["-"], "ftime-report=">, Group<f_Group>,
   Flags<[CC1Option]>, Values<"per-pass,per-pass-run">,
   MarshallingInfoFlag<CodeGenOpts<"TimePassesPerRun">>,
-  HelpText<"(For new pass manager) \"per-pass\": one report for each pass; "
-           "\"per-pass-run\": one report for each pass invocation">;
+  HelpText<"(For new pass manager) 'per-pass': one report for each pass; "
+           "'per-pass-run': one report for each pass invocation">;
 def ftime_trace : Flag<["-"], "ftime-trace">, Group<f_Group>,
   HelpText<"Turn on time profiler. Generates JSON file based on output filename.">,
   DocBrief<[{
@@ -2891,7 +2891,7 @@
   NegFlag<SetFalse>>;
 def fbasic_block_sections_EQ : Joined<["-"], "fbasic-block-sections=">, Group<f_Group>,
   Flags<[CC1Option, CC1AsOption]>,
-  HelpText<"Place each function's basic blocks in unique sections (ELF Only) : all | labels | none | list=<file>">,
+  HelpText<"Place each function's basic blocks in unique sections (ELF Only)">,
   DocBrief<[{Generate labels for each basic block or place each basic block or a subset of basic blocks in its own section.}]>,
   Values<"all,labels,none,list=">,
   MarshallingInfoString<CodeGenOpts<"BBSections">, [{"none"}]>;
@@ -3055,7 +3055,7 @@
   Group<g_flags_Group>;
 def gsplit_dwarf : Flag<["-"], "gsplit-dwarf">, Group<g_flags_Group>;
 def gsplit_dwarf_EQ : Joined<["-"], "gsplit-dwarf=">, Group<g_flags_Group>,
-  HelpText<"Set DWARF fission mode to either 'split' or 'single'">,
+  HelpText<"Set DWARF fission mode">,
   Values<"split,single">;
 def gno_split_dwarf : Flag<["-"], "gno-split-dwarf">, Group<g_flags_Group>;
 def gsimple_template_names : Flag<["-"], "gsimple-template-names">, Group<g_flags_Group>;
@@ -3292,11 +3292,11 @@
   HelpText<"Disable stack probes which are enabled by default">,
   MarshallingInfoFlag<CodeGenOpts<"NoStackArgProbe">>;
 def mthread_model : Separate<["-"], "mthread-model">, Group<m_Group>, Flags<[CC1Option]>,
-  HelpText<"The thread model to use, e.g. posix, single (posix by default)">, Values<"posix,single">,
+  HelpText<"The thread model to use. Default is 'posix')">, Values<"posix,single">,
   NormalizedValues<["POSIX", "Single"]>, NormalizedValuesScope<"LangOptions::ThreadModelKind">,
   MarshallingInfoEnum<LangOpts<"ThreadModel">, "POSIX">;
 def meabi : Separate<["-"], "meabi">, Group<m_Group>, Flags<[CC1Option]>,
-  HelpText<"Set EABI type, e.g. 4, 5 or gnu (default depends on triple)">, Values<"default,4,5,gnu">,
+  HelpText<"Set EABI type. Default depends on triple)">, Values<"default,4,5,gnu">,
   MarshallingInfoEnum<TargetOpts<"EABIVersion">, "Default">,
   NormalizedValuesScope<"llvm::EABI">,
   NormalizedValues<["Default", "EABI4", "EABI5", "GNU"]>;
@@ -3484,7 +3484,7 @@
   NegFlag<SetFalse, [CC1Option]>>, Group<m_Group>;
 
 def mcode_object_version_EQ : Joined<["-"], "mcode-object-version=">, Group<m_Group>,
-  HelpText<"Specify code object ABI version. Allowed values are 2, 3, 4, and 5. Defaults to 4. (AMDGPU only)">,
+  HelpText<"Specify code object ABI version. Defaults to 4. (AMDGPU only)">,
   Flags<[CC1Option]>,
   Values<"none,2,3,4,5">,
   NormalizedValuesScope<"TargetOptions">,
@@ -5173,7 +5173,7 @@
   HelpText<"Enable additional debug output">,
   MarshallingInfoString<CodeGenOpts<"DebugPass">>;
 def mframe_pointer_EQ : Joined<["-"], "mframe-pointer=">,
-  HelpText<"Specify which frame pointers to retain (all, non-leaf, none).">, Values<"all,non-leaf,none">,
+  HelpText<"Specify which frame pointers to retain.">, Values<"all,non-leaf,none">,
   NormalizedValuesScope<"CodeGenOptions::FramePointerKind">, NormalizedValues<["All", "NonLeaf", "None"]>,
   MarshallingInfoEnum<CodeGenOpts<"FramePointer">, "None">;
 def mdisable_tail_calls : Flag<["-"], "mdisable-tail-calls">,
@@ -5299,8 +5299,7 @@
       HelpText<"Generate M NOPs before function entry">,
       MarshallingInfoInt<CodeGenOpts<"PatchableFunctionEntryOffset">>;
 def fprofile_instrument_EQ : Joined<["-"], "fprofile-instrument=">,
-    HelpText<"Enable PGO instrumentation. The accepted value is clang, llvm, "
-             "or none">, Values<"none,clang,llvm,csllvm">,
+    HelpText<"Enable PGO instrumentation">, Values<"none,clang,llvm,csllvm">,
     NormalizedValuesScope<"CodeGenOptions">,
     NormalizedValues<["ProfileNone", "ProfileClangInstr", "ProfileIRInstr", "ProfileCSIRInstr"]>,
     MarshallingInfoEnum<CodeGenOpts<"ProfileInstr">, "ProfileNone">;
@@ -5389,11 +5388,13 @@
   HelpText<"File for serializing diagnostics in a binary format">;
 
 def fdiagnostics_format : Separate<["-"], "fdiagnostics-format">,
-  HelpText<"Change diagnostic formatting to match IDE and command line tools">, Values<"clang,msvc,vi">,
+  HelpText<"Change diagnostic formatting to match IDE and command line tools">,
+  Values<"clang,msvc,vi">,
   NormalizedValuesScope<"DiagnosticOptions">, NormalizedValues<["Clang", "MSVC", "Vi"]>,
   MarshallingInfoEnum<DiagnosticOpts<"Format">, "Clang">;
 def fdiagnostics_show_category : Separate<["-"], "fdiagnostics-show-category">,
-  HelpText<"Print diagnostic category">, Values<"none,id,name">,
+  HelpText<"Print diagnostic category">,
+  Values<"none,id,name">,
   NormalizedValues<["0", "1", "2"]>,
   MarshallingInfoEnum<DiagnosticOpts<"ShowCategories">, "0">;
 def fno_diagnostics_use_presumed_location : Flag<["-"], "fno-diagnostics-use-presumed-location">,
@@ -5667,7 +5668,8 @@
   MarshallingInfoString<FrontendOpts<"MTMigrateDir">>;
 
 def arcmt_action_EQ : Joined<["-"], "arcmt-action=">, Flags<[CC1Option, NoDriverOption]>,
-  HelpText<"The ARC migration action to take">, Values<"check,modify,migrate">,
+  HelpText<"The ARC migration action to take">,
+  Values<"check,modify,migrate">,
   NormalizedValuesScope<"FrontendOptions">,
   NormalizedValues<["ARCMT_Check", "ARCMT_Modify", "ARCMT_Migrate"]>,
   MarshallingInfoEnum<FrontendOpts<"ARCMTAction">, "ARCMT_None">;
@@ -5772,13 +5774,15 @@
   HelpText<"Specify the class to use for constant Objective-C string objects.">,
   MarshallingInfoString<LangOpts<"ObjCConstantStringClass">>;
 def fobjc_arc_cxxlib_EQ : Joined<["-"], "fobjc-arc-cxxlib=">,
-  HelpText<"Objective-C++ Automatic Reference Counting standard library kind">, Values<"libc++,libstdc++,none">,
+  HelpText<"Objective-C++ Automatic Reference Counting standard library kind">,
+  Values<"libc++,libstdc++,none">,
   NormalizedValues<["ARCXX_libcxx", "ARCXX_libstdcxx", "ARCXX_nolib"]>,
   MarshallingInfoEnum<PreprocessorOpts<"ObjCXXARCStandardLibrary">, "ARCXX_nolib">;
 def fobjc_runtime_has_weak : Flag<["-"], "fobjc-runtime-has-weak">,
   HelpText<"The target Objective-C runtime supports ARC weak operations">;
 def fobjc_dispatch_method_EQ : Joined<["-"], "fobjc-dispatch-method=">,
-  HelpText<"Objective-C dispatch method to use">, Values<"legacy,non-legacy,mixed">,
+  HelpText<"Objective-C dispatch method to use">,
+  Values<"legacy,non-legacy,mixed">,
   NormalizedValuesScope<"CodeGenOptions">, NormalizedValues<["Legacy", "NonLegacy", "Mixed"]>,
   MarshallingInfoEnum<CodeGenOpts<"ObjCDispatchMethod">, "Legacy">;
 def disable_objc_default_synthesize_properties : Flag<["-"], "disable-objc-default-synthesize-properties">,
@@ -5825,7 +5829,8 @@
   HelpText<"Should __STATIC__ be defined">,
   MarshallingInfoFlag<LangOpts<"Static">>;
 def stack_protector : Separate<["-"], "stack-protector">,
-  HelpText<"Enable stack protectors">, Values<"0,1,2,3">,
+  HelpText<"Enable stack protectors">,
+  Values<"0,1,2,3">,
   NormalizedValuesScope<"LangOptions">,
   NormalizedValues<["SSPOff", "SSPOn", "SSPStrong", "SSPReq"]>,
   MarshallingInfoEnum<LangOpts<"StackProtector">, "SSPOff">;
@@ -5868,9 +5873,10 @@
 def ffake_address_space_map : Flag<["-"], "ffake-address-space-map">,
   HelpText<"Use a fake address space map; OpenCL testing purposes only">,
   MarshallingInfoFlag<LangOpts<"FakeAddressSpaceMap">>;
-def faddress_space_map_mangling_EQ : Joined<["-"], "faddress-space-map-mangling=">, MetaVarName<"<yes|no|target>">,
+def faddress_space_map_mangling_EQ : Joined<["-"], "faddress-space-map-mangling=">,
   HelpText<"Set the mode for address space map based mangling; OpenCL testing purposes only">,
-  Values<"target,no,yes">, NormalizedValuesScope<"LangOptions">,
+  Values<"target,no,yes">,
+  NormalizedValuesScope<"LangOptions">,
   NormalizedValues<["ASMM_Target", "ASMM_Off", "ASMM_On"]>,
   MarshallingInfoEnum<LangOpts<"AddressSpaceMapMangling">, "ASMM_Target">;
 def funknown_anytype : Flag<["-"], "funknown-anytype">,
@@ -5908,7 +5914,8 @@
   MarshallingInfoFlag<LangOpts<"HalfArgsAndReturns">>,
   ImpliedByAnyOf<[fnative_half_arguments_and_returns.KeyPath]>;
 def fdefault_calling_conv_EQ : Joined<["-"], "fdefault-calling-conv=">,
-  HelpText<"Set default calling convention">, Values<"cdecl,fastcall,stdcall,vectorcall,regcall">,
+  HelpText<"Set default calling convention">,
+  Values<"cdecl,fastcall,stdcall,vectorcall,regcall">,
   NormalizedValuesScope<"LangOptions">,
   NormalizedValues<["DCC_CDecl", "DCC_FastCall", "DCC_StdCall", "DCC_VectorCall", "DCC_RegCall"]>,
   MarshallingInfoEnum<LangOpts<"DefaultCallingConv">, "DCC_None">;
@@ -5923,7 +5930,8 @@
   HelpText<"Preserve 3-component vector type">,
   MarshallingInfoFlag<CodeGenOpts<"PreserveVec3Type">>;
 def fwchar_type_EQ : Joined<["-"], "fwchar-type=">,
-  HelpText<"Select underlying type for wchar_t">, Values<"char,short,int">,
+  HelpText<"Select underlying type for wchar_t">,
+  Values<"char,short,int">,
   NormalizedValues<["1", "2", "4"]>,
   MarshallingInfoEnum<LangOpts<"WCharSize">, "0">;
 defm signed_wchar : BoolOption<"f", "signed-wchar",
Index: llvm/utils/TableGen/OptRSTEmitter.cpp
===================================================================
--- llvm/utils/TableGen/OptRSTEmitter.cpp
+++ llvm/utils/TableGen/OptRSTEmitter.cpp
@@ -60,18 +60,45 @@
       // Print the option name.
       OS << R->getValueAsString("Name");
 
+      StringRef MetaVarName;
       // Print the meta-variable.
       if (!isa<UnsetInit>(R->getValueInit("MetaVarName"))) {
+        MetaVarName = R->getValueAsString("MetaVarName");
+      } else if (!isa<UnsetInit>(R->getValueInit("Values")))
+        MetaVarName = "<value>";
+
+      if (!MetaVarName.empty()) {
         OS << '=';
-        OS.write_escaped(R->getValueAsString("MetaVarName"));
+        OS.write_escaped(MetaVarName);
       }
 
       OS << "\n\n";
 
+      std::string HelpText;
       // The option help text.
       if (!isa<UnsetInit>(R->getValueInit("HelpText"))) {
+        HelpText = R->getValueAsString("HelpText").trim().str();
+        if (!HelpText.empty() && HelpText.back() != '.')
+          HelpText.push_back('.');
+      }
+
+      if (!isa<UnsetInit>(R->getValueInit("Values"))) {
+        SmallVector<StringRef> Values;
+        SplitString(R->getValueAsString("Values"), Values, ",");
+        HelpText += (" " + MetaVarName + " can be ").str();
+
+        if (Values.size() == 1) {
+          HelpText += ("'" + Values.front() + "'.").str();
+        } else {
+          HelpText += "one of '";
+          HelpText += join(Values.begin(), Values.end() - 1, "', '");
+          HelpText += ("' or '" + Values.back() + "'.").str();
+        }
+      }
+
+      if (!HelpText.empty()) {
         OS << ' ';
-        OS.write_escaped(R->getValueAsString("HelpText"));
+        OS.write_escaped(HelpText);
         OS << "\n\n";
       }
     }