[llvm] [llvm-objcopy] Improve help messages (PR #82830)

[Fangrui Song via llvm-commits]

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@@ -97,24 +92,25 @@ def S : Flag<["-"], "S">,
         Alias<strip_all>,
         HelpText<"Alias for --strip-all">;
 def strip_dwo : Flag<["--"], "strip-dwo">,
-                HelpText<"Remove all DWARF .dwo sections from file">;
+                HelpText<"Remove all DWARF .dwo sections">;
 def strip_non_alloc
     : Flag<["--"], "strip-non-alloc">,
-      HelpText<"Remove all non-allocated sections outside segments">;
+      HelpText<"Remove all non-allocated sections that are not within segments">;
 defm strip_unneeded_symbol
     : Eq<"strip-unneeded-symbol",
-         "Remove symbol <symbol> if it is not needed by relocations">,
+         "Remove all symbols named <symbol> that are local or undefined and "
+         "are not required by any relocation">,
       MetaVarName<"symbol">;
 defm strip_unneeded_symbols
     : Eq<"strip-unneeded-symbols",
-         "Reads a list of symbols from <filename> and removes them "
-         "if they are not needed by relocations">,
+         "Remove all symbols whose names appear in the file <file>, if they "
+         "are local or undefined and are not required by any relocation">,
       MetaVarName<"filename">;
 
 defm subsystem
     : Eq<"subsystem",
-         "Set PE subsystem and version">,
-      MetaVarName<"name[:version]">;
+         "Set the PE subsystem, optionally subsystem version">,
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MaskRay wrote:

llvm-objcopy.rst uses "Set the PE subsystem, and optionally subsystem version.". Let me just use its version.

https://github.com/llvm/llvm-project/pull/82830