Simplify `ld.lld --help` message.

[ruiu]

Summary

Previously, we printed out two lines of help messages for --foo bar
and --foo=bar like this:

--soname=<value>        Set DT_SONAME
--soname <value>        Set DT_SONAME
--sort-section=<value>  Specifies sections sorting rule when linkerscript is used
--sort-section <value>  Specifies sections sorting rule when linkerscript is used

This change eliminates duplicate lines that doesn't contain = for such
options like this.

--soname=<value>        Set DT_SONAME
--sort-section=<value>  Specifies sections sorting rule when linkerscript is used

[smeenai]

Nice!

[pcc]

LGTM

ELF/Options.td

 include "llvm/Option/OptParser.td"
 
 // For options whose names are multiple letters, either one dash or
 // two can precede the option name except those that start with 'o'.
 class F<string name>: Flag<["--", "-"], name>;
 class J<string name>: Joined<["--", "-"], name>;
 
-multiclass Eq<string name> {
+multiclass Eq<string name, string help> {
   def NAME: Separate<["--", "-"], name>;
-  def NAME # _eq: Joined<["--", "-"], name # "=">, Alias<!cast<Separate>(NAME)>;
+  def NAME # _eq: Joined<["--", "-"], name # "=">, Alias<!cast<Separate>(NAME)>,
+    HelpText<help>;
 }
 
 multiclass B<string name, string help1, string help2> {
   def NAME: Flag<["--", "-"], name>, HelpText<help1>;
   def no_ # NAME: Flag<["--", "-"], "no-" # name>, HelpText<help2>;
 }
 
-defm auxiliary: Eq<"auxiliary">,
-  HelpText<"Set DT_AUXILIARY field to the specified name">;
+defm auxiliary: Eq<"auxiliary", "Set DT_AUXILIARY field to the specified name">;
 
 def Bsymbolic: F<"Bsymbolic">, HelpText<"Bind defined symbols locally">;
 
 def Bsymbolic_functions: F<"Bsymbolic-functions">,
   HelpText<"Bind defined function symbols locally">;
 
 def Bdynamic: F<"Bdynamic">, HelpText<"Link against shared libraries">;
 
 def Bstatic: F<"Bstatic">, HelpText<"Do not link against shared libraries">;
 
 def build_id: F<"build-id">, HelpText<"Generate build ID note">;
 
 def build_id_eq: J<"build-id=">, HelpText<"Generate build ID note">;
 
 defm check_sections : B<"check-sections",
     "Check section addresses for overlaps",
     "Do not check section addresses for overlaps">;
 
-defm compress_debug_sections : Eq<"compress-debug-sections">,
-  HelpText<"Compress DWARF debug sections">;
+defm compress_debug_sections:
+  Eq<"compress-debug-sections", "Compress DWARF debug sections">;
 
-defm defsym: Eq<"defsym">, HelpText<"Define a symbol alias">;
+defm defsym: Eq<"defsym", "Define a symbol alias">;
 
-defm library_path: Eq<"library-path">,
-  HelpText<"Add a directory to the library search path">, MetaVarName<"<dir>">;
+defm library_path:
+  Eq<"library-path", "Add a directory to the library search path">, MetaVarName<"<dir>">;
 
 def O: JoinedOrSeparate<["-"], "O">, HelpText<"Optimize output file size">;
 
-defm Tbss: Eq<"Tbss">,
-  HelpText<"Same as --section-start with .bss as the sectionname">;
+defm Tbss: Eq<"Tbss", "Same as --section-start with .bss as the sectionname">;
 
-defm Tdata: Eq<"Tdata">,
-  HelpText<"Same as --section-start with .data as the sectionname">;
+defm Tdata: Eq<"Tdata", "Same as --section-start with .data as the sectionname">;
 
-defm Ttext: Eq<"Ttext">,
-  HelpText<"Same as --section-start with .text as the sectionname">;
+defm Ttext: Eq<"Ttext", "Same as --section-start with .text as the sectionname">;
 
 defm allow_multiple_definition: B<"allow-multiple-definition",
     "Allow multiple definitions",
     "Do not allow multiple definitions">;
 
 defm apply_dynamic_relocs: B<"apply-dynamic-relocs",
     "Apply dynamic relocations to place",
     "Do not apply dynamic relocations to place">;
 
 defm as_needed: B<"as-needed",
     "Only set DT_NEEDED for shared libraries if used",
     "Always set DT_NEEDED for shared libraries">;
 
-defm call_graph_ordering_file: Eq<"call-graph-ordering-file">,
-  HelpText<"Layout sections to optimize the given callgraph">;
+defm call_graph_ordering_file:
+  Eq<"call-graph-ordering-file", "Layout sections to optimize the given callgraph">;
 
 // -chroot doesn't have a help text because it is an internal option.
-defm chroot: Eq<"chroot">;
+def chroot: Separate<["--", "-"], "chroot">;
 
 def color_diagnostics: F<"color-diagnostics">,
   HelpText<"Use colors in diagnostics">;
 
 def color_diagnostics_eq: J<"color-diagnostics=">,
   HelpText<"Use colors in diagnostics; one of 'always', 'never', 'auto'">;
 
 defm cref: B<"cref",

 def discard_all: F<"discard-all">, HelpText<"Delete all local symbols">;
 
 def discard_locals: F<"discard-locals">,
   HelpText<"Delete temporary local symbols">;
 
 def discard_none: F<"discard-none">,
   HelpText<"Keep all symbols in the symbol table">;
 
-defm dynamic_linker: Eq<"dynamic-linker">,
-  HelpText<"Which dynamic linker to use">;
+defm dynamic_linker: Eq<"dynamic-linker", "Which dynamic linker to use">;
 
-defm dynamic_list: Eq<"dynamic-list">,
-  HelpText<"Read a list of dynamic symbols">;
+defm dynamic_list: Eq<"dynamic-list", "Read a list of dynamic symbols">;
 
 defm eh_frame_hdr: B<"eh-frame-hdr",
     "Request creation of .eh_frame_hdr section and PT_GNU_EH_FRAME segment header",
     "Do not create .eh_frame_hdr section">;
 
 def emit_relocs: F<"emit-relocs">, HelpText<"Generate relocations in output">;
 
 def enable_new_dtags: F<"enable-new-dtags">,
   HelpText<"Enable new dynamic tags">;
 
 def end_group: F<"end-group">,
   HelpText<"Ignored for compatibility with GNU unless you pass --warn-backrefs">;
 
 def end_lib: F<"end-lib">,
   HelpText<"End a grouping of objects that should be treated as if they were together in an archive">;
 
-defm entry: Eq<"entry">, HelpText<"Name of entry point symbol">,
+defm entry: Eq<"entry", "Name of entry point symbol">,
   MetaVarName<"<entry>">;
 
-defm error_limit: Eq<"error-limit">,
-  HelpText<"Maximum number of errors to emit before stopping (0 = no limit)">;
+defm error_limit:
+  Eq<"error-limit", "Maximum number of errors to emit before stopping (0 = no limit)">;
 
 def error_unresolved_symbols: F<"error-unresolved-symbols">,
   HelpText<"Report unresolved symbols as errors">;
 
-defm exclude_libs: Eq<"exclude-libs">,
-  HelpText<"Exclude static libraries from automatic export">;
+defm exclude_libs: Eq<"exclude-libs", "Exclude static libraries from automatic export">;
 
 defm export_dynamic: B<"export-dynamic",
     "Put symbols in the dynamic symbol table",
     "Do not put symbols in the dynamic symbol table">;
 
-defm export_dynamic_symbol: Eq<"export-dynamic-symbol">,
-  HelpText<"Put a symbol in the dynamic symbol table">;
+defm export_dynamic_symbol:
+  Eq<"export-dynamic-symbol", "Put a symbol in the dynamic symbol table">;
 
 defm fatal_warnings: B<"fatal-warnings",
     "Treat warnings as errors",
     "Do not treat warnings as errors">;
 
-defm filter: Eq<"filter">,
-  HelpText<"Set DT_FILTER field to the specified name">;
+defm filter: Eq<"filter", "Set DT_FILTER field to the specified name">;
 
-defm fini: Eq<"fini">,
-  HelpText<"Specify a finalizer function">, MetaVarName<"<symbol>">;
+defm fini: Eq<"fini", "Specify a finalizer function">, MetaVarName<"<symbol>">;
 
 def fix_cortex_a53_843419: F<"fix-cortex-a53-843419">,
   HelpText<"Apply fixes for AArch64 Cortex-A53 erratum 843419">;
 
-defm format: Eq<"format">,
-  HelpText<"Change the input format of the inputs following this option">,
+defm format: Eq<"format", "Change the input format of the inputs following this option">,
   MetaVarName<"<input-format>">;
 
 defm gc_sections: B<"gc-sections",
     "Enable garbage collection of unused sections",
     "Disable garbage collection of unused sections">;
 
 defm gdb_index: B<"gdb-index",
     "Generate .gdb_index section",
     "Do not generate .gdb_index section">;
 
 defm gnu_unique: B<"gnu-unique",
   "Enable STB_GNU_UNIQUE symbol binding",
   "Disable STB_GNU_UNIQUE symbol binding">;
 
-defm hash_style: Eq<"hash-style">,
-  HelpText<"Specify hash style (sysv, gnu or both)">;
+defm hash_style: Eq<"hash-style", "Specify hash style (sysv, gnu or both)">;
 
 def help: F<"help">, HelpText<"Print option help">;
 
 def icf_all: F<"icf=all">, HelpText<"Enable identical code folding">;
 
 def icf_none: F<"icf=none">, HelpText<"Disable identical code folding">;
 
 def ignore_function_address_equality: F<"ignore-function-address-equality">,
   HelpText<"lld can break the address equality of functions">;
 
 def ignore_data_address_equality: F<"ignore-data-address-equality">,
   HelpText<"lld can break the address equality of data">;
 
-defm image_base : Eq<"image-base">, HelpText<"Set the base address">;
+defm image_base: Eq<"image-base", "Set the base address">;
 
-defm init: Eq<"init">, HelpText<"Specify an initializer function">,
+defm init: Eq<"init", "Specify an initializer function">,
   MetaVarName<"<symbol>">;
 
-defm just_symbols: Eq<"just-symbols">, HelpText<"Just link symbols">;
+defm just_symbols: Eq<"just-symbols", "Just link symbols">;
 
-defm keep_unique: Eq<"keep-unique">, HelpText<"Do not fold this symbol during ICF">;
+defm keep_unique: Eq<"keep-unique", "Do not fold this symbol during ICF">;
 
-defm library: Eq<"library">, HelpText<"Root name of library to use">,
+defm library: Eq<"library", "Root name of library to use">,
   MetaVarName<"<libName>">;
 
 def m: JoinedOrSeparate<["-"], "m">, HelpText<"Set target emulation">;
 
-defm Map: Eq<"Map">, HelpText<"Print a link map to the specified file">;
+defm Map: Eq<"Map", "Print a link map to the specified file">;
 
 defm merge_exidx_entries: B<"merge-exidx-entries",
     "Enable merging .ARM.exidx entries",
     "Disable merging .ARM.exidx entries">;
 
 def nostdlib: F<"nostdlib">,
   HelpText<"Only search directories specified on the command line">;
 
def o: JoinedOrSeparate<["-"], "o">, MetaVarName<"<path>">,
   HelpText<"Path to file to write output">;
 
 def oformat: Separate<["--"], "oformat">, MetaVarName<"<format>">,
   HelpText<"Specify the binary format for the output object file">;
 
 def omagic: Flag<["--"], "omagic">, MetaVarName<"<magic>">,
   HelpText<"Set the text and data sections to be readable and writable">;
 
-defm orphan_handling: Eq<"orphan-handling">,
-  HelpText<"Control how orphan sections are handled when linker script used">;
+defm orphan_handling:
+  Eq<"orphan-handling", "Control how orphan sections are handled when linker script used">;
 
-defm pack_dyn_relocs: Eq<"pack-dyn-relocs">, MetaVarName<"<format>">,
-  HelpText<"Pack dynamic relocations in the given format (none or android)">;
+defm pack_dyn_relocs:
+  Eq<"pack-dyn-relocs", "Pack dynamic relocations in the given format (none or android)">,
+  MetaVarName<"<format>">;
 
 defm pie: B<"pie",
     "Create a position independent executable",
     "Do not create a position independent executable">;
 
 defm print_gc_sections: B<"print-gc-sections",
     "List removed unused sections",
     "Do not list removed unused sections">;
 
 defm print_icf_sections: B<"print-icf-sections",
     "List identical folded sections",
     "Do not list identical folded sections">;
 
 def print_map: F<"print-map">,
   HelpText<"Print a link map to the standard output">;
 
-defm reproduce: Eq<"reproduce">,
-  HelpText<"Dump linker invocation and input files for debugging">;
+defm reproduce: Eq<"reproduce", "Dump linker invocation and input files for debugging">;
 
-defm rpath: Eq<"rpath">, HelpText<"Add a DT_RUNPATH to the output">;
+defm rpath: Eq<"rpath", "Add a DT_RUNPATH to the output">;
 
 def relocatable: F<"relocatable">, HelpText<"Create relocatable object file">;
 
-defm retain_symbols_file: Eq<"retain-symbols-file">,
-  HelpText<"Retain only the symbols listed in the file">,
+defm retain_symbols_file:
+  Eq<"retain-symbols-file", "Retain only the symbols listed in the file">,
   MetaVarName<"<file>">;
 
-defm script: Eq<"script">, HelpText<"Read linker script">;
+defm script: Eq<"script", "Read linker script">;
 
-defm section_start: Eq<"section-start">, MetaVarName<"<address>">,
-  HelpText<"Set address of section">;
+defm section_start: Eq<"section-start", "Set address of section">,
+  MetaVarName<"<address>">;
 
 def shared: F<"shared">, HelpText<"Build a shared object">;
 
-defm soname: Eq<"soname">, HelpText<"Set DT_SONAME">;
+defm soname: Eq<"soname", "Set DT_SONAME">;
 
-defm sort_section: Eq<"sort-section">,
-  HelpText<"Specifies sections sorting rule when linkerscript is used">;
+defm sort_section:
+  Eq<"sort-section", "Specifies sections sorting rule when linkerscript is used">;
 
 def start_group: F<"start-group">,
   HelpText<"Ignored for compatibility with GNU unless you pass --warn-backrefs">;
 
 def start_lib: F<"start-lib">,
   HelpText<"Start a grouping of objects that should be treated as if they were together in an archive">;
 
 def strip_all: F<"strip-all">, HelpText<"Strip all symbols">;
 
 def strip_debug: F<"strip-debug">, HelpText<"Strip debugging information">;
 
-defm symbol_ordering_file: Eq<"symbol-ordering-file">,
-  HelpText<"Layout sections to place symbols in the order specified by symbol ordering file">;
+defm symbol_ordering_file:
+  Eq<"symbol-ordering-file", "Layout sections to place symbols in the order specified by symbol ordering file">;
 
-defm sysroot: Eq<"sysroot">, HelpText<"Set the system root">;
+defm sysroot: Eq<"sysroot", "Set the system root">;
 
 def target1_rel: F<"target1-rel">, HelpText<"Interpret R_ARM_TARGET1 as R_ARM_REL32">;
 
 def target1_abs: F<"target1-abs">, HelpText<"Interpret R_ARM_TARGET1 as R_ARM_ABS32">;
 
-defm target2: Eq<"target2">,
-  HelpText<"Interpret R_ARM_TARGET2 as <type>, where <type> is one of rel, abs, or got-rel">,
+defm target2:
+  Eq<"target2", "Interpret R_ARM_TARGET2 as <type>, where <type> is one of rel, abs, or got-rel">,
   MetaVarName<"<type>">;
 
 defm threads: B<"threads",
     "Run the linker multi-threaded",
     "Do not run the linker multi-threaded">;
 
 def trace: F<"trace">, HelpText<"Print the names of the input files">;
 
-defm trace_symbol : Eq<"trace-symbol">, HelpText<"Trace references to symbols">;
+defm trace_symbol: Eq<"trace-symbol", "Trace references to symbols">;
 
-defm undefined: Eq<"undefined">,
-  HelpText<"Force undefined symbol during linking">;
+defm undefined: Eq<"undefined", "Force undefined symbol during linking">;
 
-defm unresolved_symbols: Eq<"unresolved-symbols">,
-  HelpText<"Determine how to handle unresolved symbols">;
+defm unresolved_symbols:
+  Eq<"unresolved-symbols", "Determine how to handle unresolved symbols">;
 
 defm undefined_version: B<"undefined-version",
   "Allow unused version in version script",
   "Report version scripts that refer undefined symbols">;
 
-defm rsp_quoting: Eq<"rsp-quoting">,
-  HelpText<"Quoting style for response files. Values supported: windows|posix">;
+defm rsp_quoting:
+  Eq<"rsp-quoting", "Quoting style for response files. Values supported: windows|posix">;
 
 def v: Flag<["-"], "v">, HelpText<"Display the version number">;
 
 def verbose: F<"verbose">, HelpText<"Verbose mode">;
 
 def version: F<"version">, HelpText<"Display the version number and exit">;
 
-defm version_script: Eq<"version-script">, HelpText<"Read a version script">;
+defm version_script: Eq<"version-script", "Read a version script">;
 
 defm warn_backrefs: B<"warn-backrefs",
     "Warn about backward symbol references to fetch archive members",
     "Do not warn about backward symbol references to fetch archive members">;
 
 defm warn_common: B<"warn-common",
     "Warn about duplicate common symbols",
     "Do not warn about duplicate common symbols">;
 
 defm warn_symbol_ordering : B<"warn-symbol-ordering",
     "Warn about problems with the symbol ordering file",
     "Do not warn about problems with the symbol ordering file">;
 
 def warn_unresolved_symbols: F<"warn-unresolved-symbols">,
   HelpText<"Report unresolved symbols as warnings">;
 
 defm whole_archive: B<"whole-archive",
     "Force load of all members in a static library",
     "Do not force load of all members in a static library">;
 
-defm wrap: Eq<"wrap">, HelpText<"Use wrapper functions for symbol">,
+defm wrap: Eq<"wrap", "Use wrapper functions for symbol">,
   MetaVarName<"<symbol>">;
 
 def z: JoinedOrSeparate<["-"], "z">, MetaVarName<"<option>">,
   HelpText<"Linker option extensions">;
 
 // Aliases
 def alias_auxiliary: Separate<["-"], "f">, Alias<auxiliary>;
 def alias_Bdynamic_call_shared: F<"call_shared">, Alias<Bdynamic>;
def lto_newpm_passes: J<"lto-newpm-passes=">,
   HelpText<"Passes to run during LTO">;
 def lto_O: J<"lto-O">, MetaVarName<"<opt-level>">,
   HelpText<"Optimization level for LTO">;
 def lto_partitions: J<"lto-partitions=">,
   HelpText<"Number of LTO codegen partitions">;
 def lto_sample_profile: J<"lto-sample-profile=">,
   HelpText<"Sample profile file path">;
 def disable_verify: F<"disable-verify">;
-defm mllvm: Eq<"mllvm">;
+defm mllvm: Eq<"mllvm", "Additional arguments to forward to LLVM's option processing">;
 def opt_remarks_filename: Separate<["--"], "opt-remarks-filename">,
   HelpText<"YAML output file for optimization remarks">;
 def opt_remarks_with_hotness: Flag<["--"], "opt-remarks-with-hotness">,
   HelpText<"Include hotness information in the optimization remarks file">;
-defm plugin_opt: Eq<"plugin-opt">,
-  HelpText<"specifies LTO options for compatibility with GNU linkers">;
+defm plugin_opt: Eq<"plugin-opt", "specifies LTO options for compatibility with GNU linkers">;
 def save_temps: F<"save-temps">;
 def thinlto_cache_dir: J<"thinlto-cache-dir=">,
   HelpText<"Path to ThinLTO cached object file directory">;
-defm thinlto_cache_policy: Eq<"thinlto-cache-policy">,
-  HelpText<"Pruning policy for the ThinLTO cache">;
+defm thinlto_cache_policy: Eq<"thinlto-cache-policy", "Pruning policy for the ThinLTO cache">;
 def thinlto_jobs: J<"thinlto-jobs=">, HelpText<"Number of ThinLTO jobs">;
 
 def plugin_opt_O: J<"plugin-opt=O">, Alias<lto_O>;
 def plugin_opt_debug_pass_manager: F<"plugin-opt=debug-pass-manager">, Alias<lto_debug_pass_manager>;
 def plugin_opt_disable_verify: F<"plugin-opt=disable-verify">, Alias<disable_verify>;
 def plugin_opt_jobs_eq: J<"plugin-opt=jobs=">, Alias<thinlto_jobs>;
 def plugin_opt_lto_partitions_eq: J<"plugin-opt=lto-partitions=">, Alias<lto_partitions>;
 def plugin_opt_mcpu_eq: J<"plugin-opt=mcpu=">;

 
 // Ignore LTO plugin-related options.
 // clang -flto passes -plugin and -plugin-opt to the linker. This is required
 // for ld.gold and ld.bfd to get LTO working. But it's not for lld which doesn't
 // rely on a plugin. Instead of detecting which linker is used on clang side we
 // just ignore the option on lld side as it's easier. In fact, the linker could
 // be called 'ld' and understanding which linker is used would require parsing of
 // --version output.
-defm plugin: Eq<"plugin">;
+def plugin: J<"plugin">;
 
 def plugin_opt_fresolution_eq: J<"plugin-opt=-fresolution=">;
 def plugin_opt_pass_through_eq: J<"plugin-opt=-pass-through=">;
 def plugin_opt_thinlto: J<"plugin-opt=thinlto">;
 def plugin_opt_slash: J<"plugin-opt=/">;
 
 // Options listed below are silently ignored for now for compatibility.
 def allow_shlib_undefined: F<"allow-shlib-undefined">;
 def detect_odr_violations: F<"detect-odr-violations">;
 def g: Flag<["-"], "g">;
 def long_plt: F<"long-plt">;
 def no_add_needed: F<"no-add-needed">;
 def no_allow_shlib_undefined: F<"no-allow-shlib-undefined">;
 def no_copy_dt_needed_entries: F<"no-copy-dt-needed-entries">;
 def no_ctors_in_init_array: F<"no-ctors-in-init-array">;
 def no_keep_memory: F<"no-keep-memory">;
 def no_mmap_output_file: F<"no-mmap-output-file">;
 def no_warn_mismatch: F<"no-warn-mismatch">;
-defm rpath_link: Eq<"rpath-link">;
+def rpath_link: J<"rpath-link">;
+def rpath_link_eq: J<"rpath-link=">;
 def sort_common: F<"sort-common">;
 def stats: F<"stats">;
 def warn_execstack: F<"warn-execstack">;
 def warn_once: F<"warn-once">;
 def warn_shared_textrel: F<"warn-shared-textrel">;
 def EB : F<"EB">;
 def EL : F<"EL">;
 def G: JoinedOrSeparate<["-"], "G">;
 def Qy : F<"Qy">;