[ms] [llvm-ml] Add more documentation to unsupported options

[epastor]

Summary

Add documentation for the hidden unsupported ML.exe compatibility options.

Also consumes "/c" option without a warning, since that's our default behavior.

[epastor]

Rebase on HEAD

[epastor]

Rebase on parent

[thakis]

I'd argue that we shouldn't have help texts for flags we don't support.

[epastor]

Rebase on parent

[epastor]

In D90060#2378926, @thakis wrote:

I'd argue that we shouldn't have help texts for flags we don't support.

Fair enough; abandoned.

llvm/tools/llvm-ml/Opts.td

 class UnsupportedJoinedOrSeparate<string name> :
         JoinedOrSeparate<["/", "-"], name>, Group<unsupported_Group>;
 class UnsupportedSeparate<string name> : Separate<["/", "-"], name>,
                                          Group<unsupported_Group>;
 
 def help : MLFlag<"?">,
            HelpText<"Display available options">;
 def help_long : MLFlag<"help">, Alias<help>;
+
+def assemble_only : MLFlag<"c">, HelpText<"Assemble only; do not link">;
 def define : MLJoinedOrSeparate<"D">, MetaVarName<"<macro>=<value>">,
              HelpText<"Define <macro> to <value> (or blank if <value> "
                       "omitted)">;
-def output_file : MLJoinedOrSeparate<"Fo">, HelpText<"Names the output file">;
-def include_path : MLJoinedOrSeparate<"I">,
+def output_file : MLJoinedOrSeparate<"Fo">, MetaVarName<"<filename>">,
+                  HelpText<"Names the output object file">;
+def include_path : MLJoinedOrSeparate<"I">, MetaVarName<"<path>">,
                    HelpText<"Sets path for include files">;
 def safeseh : MLFlag<"safeseh">,
               HelpText<"Mark resulting object files as either containing no "
                        "exception handlers or containing exception handlers "
                        "that are all declared with .SAFESEH. Only available in "
                        "32-bit.">;
-def assembly_file : MLJoinedOrSeparate<"Ta">,
+def assembly_file : MLJoinedOrSeparate<"Ta">, MetaVarName<"<filename>">,
                     HelpText<"Assemble source file with name not ending with "
                              "the .asm extension">;
 
 def bitness : LLVMJoined<"m">, Values<"32,64">,
               HelpText<"Target platform (x86 or x86-64)">;
 def as_lex : LLVMFlag<"as-lex">,
              HelpText<"Lex tokens from a .asm file without assembling">;
 def filetype : LLVMJoined<"filetype=">, Values<"obj,s,null">,

 def print_imm_hex : LLVMFlag<"print-imm-hex">,
                     HelpText<"Prefer hex format for immediate values in output "
                              "assembly">;
 def preserve_comments : LLVMFlag<"preserve-comments">,
                         HelpText<"Preserve comments in output assembly">;
 def save_temp_labels : LLVMFlag<"save-temp-labels">,
                        HelpText<"Don't discard temporary labels">;
 
-def tiny_model_support : UnsupportedFlag<"AT">, HelpText<"">;
-def alternate_linker : UnsupportedJoined<"Bl">, HelpText<"">;
-def assemble_only : UnsupportedFlag<"c">, HelpText<"">;
-def coff_object_file : UnsupportedFlag<"coff">, HelpText<"">;
-def preserve_identifier_case : UnsupportedFlag<"Cp">, HelpText<"">;
-def uppercase_identifiers : UnsupportedFlag<"Cu">, HelpText<"">;
-def preserve_extern_case : UnsupportedFlag<"Cx">, HelpText<"">;
-def output_preprocessed : UnsupportedFlag<"EP">, HelpText<"">;
-def errorreport : UnsupportedJoined<"ERRORREPORT">, HelpText<"">;
-def stacksize : UnsupportedSeparate<"F">, HelpText<"">;
-def executable_file : UnsupportedSeparate<"Fe">, HelpText<"">;
-def code_listing_file : UnsupportedJoined<"FI">, HelpText<"">;
-def linker_map_file : UnsupportedJoined<"Fm">, HelpText<"">;
+def tiny_model_support : UnsupportedFlag<"AT">,
+                         HelpText<"Enable tiny-memory-model support, and "
+                                  "error messages for code constructs "
+                                  "violating requirements for .com format "
+                                  "files. Only available for 32-bit x86.">;
+def alternate_linker : UnsupportedJoined<"Bl">,
+                       HelpText<"Use the specified linker">;
+def coff_object_file : UnsupportedFlag<"coff">,
+                       HelpText<"Generate COFF object module type. Only "
+                                "available for 32-bit x86.">;
+def preserve_identifier_case : UnsupportedFlag<"Cp">,
+                               HelpText<"Preserve case for all user "
+                                        "identifiers">;
+def uppercase_identifiers : UnsupportedFlag<"Cu">,
+                            HelpText<"Map all identifiers to uppercase">;
+def preserve_extern_case : UnsupportedFlag<"Cx">,
+                           HelpText<"Preserve case for all public and extern "
+                                    "symbols">;
+def output_preprocessed : UnsupportedFlag<"EP">,
+                          HelpText<"Output a preprocessed source listing on "
+                                   "STDOUT">;
+def errorreport : UnsupportedJoined<"ERRORREPORT">,
+                  Values<"NONE,PROMPT,QUEUE,SEND">, HelpText<"Deprecated">;
+def stacksize : UnsupportedSeparate<"F">, MetaVarName<"<hex value>">,
+                HelpText<"Set the stack size to <hex value>, interpreted in "
+                         "hexadecimal">;
+def executable_file : UnsupportedSeparate<"Fe">, MetaVarName<"<filename>">,
+                      HelpText<"Names the executable output file">;
+def code_listing_file : UnsupportedJoined<"FI">, MetaVarName<"<filename>">,
+                        HelpText<"Generate an assembled code listing in "
+                                 "<filename>">;
+def linker_map_file : UnsupportedJoined<"Fm">, MetaVarName<"<filename>">,
+                      HelpText<"Generate a linker map file">;
 def fp_emulator_fixups : UnsupportedFlag<"FPi">, HelpText<"">;
-def source_browser_file : UnsupportedJoined<"Fr">, HelpText<"">;
-def extended_source_browser_file : UnsupportedJoined<"FR">, HelpText<"">;
-def pascal_conventions : UnsupportedFlag<"Gc">, HelpText<"">;
-def c_conventions : UnsupportedFlag<"Gd">, HelpText<"">;
-def stdcall_conventions : UnsupportedFlag<"GZ">, HelpText<"">;
-def extern_name_limit : UnsupportedSeparate<"H">, HelpText<"">;
-def nologo : UnsupportedFlag<"nologo">, HelpText<"">;
-def omf_object_file : UnsupportedFlag<"omf">, HelpText<"">;
-def full_listing : UnsupportedFlag<"Sa">, HelpText<"">;
-def first_pass_listing : UnsupportedFlag<"Sf">, HelpText<"">;
-def listing_width : UnsupportedSeparate<"SI">, HelpText<"">;
-def listing_without_symbols : UnsupportedFlag<"Sn">, HelpText<"">;
-def listing_page_length : UnsupportedSeparate<"Sp">, HelpText<"">;
-def listing_subtitle : UnsupportedSeparate<"Ss">, HelpText<"">;
-def listing_title : UnsupportedSeparate<"St">, HelpText<"">;
-def listing_false_conditionals : UnsupportedFlag<"Sx">, HelpText<"">;
-def extra_warnings : UnsupportedFlag<"w">, HelpText<"">;
-def warning_level : UnsupportedJoined<"W">, HelpText<"">;
-def error_on_warning : UnsupportedFlag<"WX">, HelpText<"">;
-def ignore_include_envvar : UnsupportedFlag<"X">, HelpText<"">;
-def line_number_info : UnsupportedFlag<"Zd">, HelpText<"">;
-def export_all_symbols : UnsupportedFlag<"Zf">, HelpText<"">;
-def codeview_info : UnsupportedFlag<"Zi">, HelpText<"">;
-def enable_m510_option : UnsupportedFlag<"Zm">, HelpText<"">;
-def structure_packing : UnsupportedJoined<"Zp">, HelpText<"">;
-def parse_only : UnsupportedFlag<"Zs">, HelpText<"">;
+def source_browser_file : UnsupportedJoined<"Fr">, MetaVarName<"<filename>">,
+                          HelpText<"Generate a .sbr file">;
+def extended_source_browser_file : UnsupportedJoined<"FR">,
+                                   MetaVarName<"<filename>">,
+                                   HelpText<"Generate an extended .sbr file">;
+def pascal_conventions : UnsupportedFlag<"Gc">,
+                         HelpText<"Use Pascal/FORTRAN calling and naming "
+                                  "conventions. Only available for 32-bit "
+                                  "x86.">;
+def c_conventions : UnsupportedFlag<"Gd">,
+                    HelpText<"Use C-style calling and naming conventions. Only "
+                             "available for 32-bit x86.">;
+def stdcall_conventions : UnsupportedFlag<"GZ">,
+                          HelpText<"Use __stdcall calling and naming "
+                                   "conventions. Only available for 32-bit "
+                                   "x86.">;
+def extern_name_limit : UnsupportedSeparate<"H">, MetaVarName<"<numchars>">,
+                        HelpText<"Restrict external names to <numchars> "
+                                 "characters. Only available for 32-bit x86.">;
+def nologo : UnsupportedFlag<"nologo">,
+             HelpText<"Suppress all messages for successful assembly">;
+def omf_object_file : UnsupportedFlag<"omf">,
+                      HelpText<"Generate OMF object module type. Only "
+                               "available for 32-bit x86.">;
+def full_listing : UnsupportedFlag<"Sa">,
+                   HelpText<"Enable all information in the source listing">;
+def first_pass_listing : UnsupportedFlag<"Sf">,
+                         HelpText<"Add a first-pass listing to the listing "
+                                  "file">;
+def listing_width : UnsupportedSeparate<"SI">, MetaVarName<"<width>">,
+                    HelpText<"Set the line width of the source listing to "
+                             "<width> characters per line, or unrestricted if "
+                             "<width> is 0">;
+def listing_without_symbols : UnsupportedFlag<"Sn">,
+                              HelpText<"Disable symbol table in source "
+                                       "listing">;
+def listing_page_length : UnsupportedSeparate<"Sp">, MetaVarName<"<numlines>">,
+                          HelpText<"Set the page length of the source listing "
+                                   "to <numlines> lines per page, or "
+                                   "unrestricted if <numlines> is 0">;
+def listing_subtitle : UnsupportedSeparate<"Ss">, MetaVarName<"<text>">,
+                       HelpText<"Set the source listing subtitle">;
+def listing_title : UnsupportedSeparate<"St">, MetaVarName<"<text>">,
+                    HelpText<"Set the source listing title">;
+def listing_false_conditionals : UnsupportedFlag<"Sx">,
+                                 HelpText<"Include contents of false "
+                                          "conditionals in the source listing">;
+def extra_warnings : UnsupportedFlag<"w">, HelpText<"Equivalent to /W0 /WX">;
+def warning_level : UnsupportedJoined<"W">, MetaVarName<"<level>">,
+                    HelpText<"Show all warnings up to level <level>">;
+def error_on_warning : UnsupportedFlag<"WX">,
+                       HelpText<"Upgrade all warnings to errors">;
+def ignore_include_envvar : UnsupportedFlag<"X">,
+                            HelpText<"Ignore the INCLUDE environment variable">;
+def line_number_info : UnsupportedFlag<"Zd">,
+                       HelpText<"Include line-number information in the object "
+                                "file">;
+def export_all_symbols : UnsupportedFlag<"Zf">,
+                         HelpText<"Export all symbols as public">;
+def codeview_info : UnsupportedFlag<"Zi">,
+                    HelpText<"Include CodeView information in the object file">;
+def enable_m510_option : UnsupportedFlag<"Zm">,
+                         HelpText<"Enable the M510 option for increased MASM "
+                                  "5.1 compatibility. Only available for "
+                                  "32-bit x86.">;
+def structure_packing : UnsupportedJoined<"Zp">, MetaVarName<"<alignment>">,
+                        HelpText<"Pack structures with the specified "
+                                 "alignment by default">;
+def parse_only : UnsupportedFlag<"Zs">, HelpText<"Run a syntax-check only">;