lld-link: Allow /? as option prefix, like -? is allowed

link.exe seems to allow `/?foo` and `-?foo` in addition to `/foo` and `-foo`.

Since lld-link already supports the `-?foo` spelling, support `/?foo` as well.

Differential Revision: https://reviews.llvm.org/D61375

llvm-svn: 360150

lld/COFF/Options.td

@@ -3,11 +3,11 @@ include "llvm/Option/OptParser.td"
 // link.exe accepts options starting with either a dash or a slash.
 
 // Flag that takes no arguments.
-class F<string name> : Flag<["/", "-", "-?"], name>;
+class F<string name> : Flag<["/", "-", "/?", "-?"], name>;
 
 // Flag that takes one argument after ":".
 class P<string name, string help> :
-      Joined<["/", "-", "-?"], name#":">, HelpText<help>;
+      Joined<["/", "-", "/?", "-?"], name#":">, HelpText<help>;
 
 // Boolean flag which can be suffixed by ":no". Using it unsuffixed turns the
 // flag on and using it suffixed by ":no" turns it off.
@@ -66,7 +66,8 @@ def timestamp : P<"timestamp", "Specify the PE header timestamp">;
 def version : P<"version", "Specify a version number in the PE header">;
 def wholearchive_file : P<"wholearchive", "Include all object files from this archive">;
 
-def disallowlib : Joined<["/", "-", "-?"], "disallowlib:">, Alias<nodefaultlib>;
+def disallowlib : Joined<["/", "-", "/?", "-?"], "disallowlib:">,
+    Alias<nodefaultlib>;
 
 def manifest : F<"manifest">, HelpText<"Create .manifest file">;
 def manifest_colon : P<
@@ -84,11 +85,11 @@ def manifestinput : P<
 // We cannot use multiclass P because class name "incl" is different
 // from its command line option name. We do this because "include" is
 // a reserved keyword in tablegen.
-def incl : Joined<["/", "-"], "include:">,
+def incl : Joined<["/", "-", "/?", "-?"], "include:">,
     HelpText<"Force symbol to be added to symbol table as undefined one">;
 
 // "def" is also a keyword.
-def deffile : Joined<["/", "-"], "def:">,
+def deffile : Joined<["/", "-", "/?", "-?"], "def:">,
     HelpText<"Use module-definition file">;
 
 def debug : F<"debug">, HelpText<"Embed a symbol table in the image">;
@@ -155,7 +156,9 @@ defm tsaware  : B<"tsaware",
                   "Create non-Terminal Server aware executable">;
 
 def help : F<"help">;
-def help_q : Flag<["/?", "-?"], "">, Alias<help>;
+
+// /?? and -?? must be before /? and -? to not confuse lib/Options.
+def help_q : Flag<["/??", "-??", "/?", "-?"], "">, Alias<help>;
 
 // LLD extensions
 def exclude_all_symbols : F<"exclude-all-symbols">;
@@ -165,7 +168,7 @@ defm demangle : B<"demangle",
     "Do not demangle symbols in output">;
 def kill_at : F<"kill-at">;
 def lldmingw : F<"lldmingw">;
-def output_def : Joined<["/", "-"], "output-def:">;
+def output_def : Joined<["/", "-", "/?", "-?"], "output-def:">;
 def pdb_source_path : P<"pdbsourcepath",
                         "Base path used to make relative source file path absolute in PDB">;
 def rsp_quoting : Joined<["--"], "rsp-quoting=">,
@@ -178,15 +181,15 @@ defm threads: B<"threads",
 
 // Flags for debugging
 def lldmap : F<"lldmap">;
-def lldmap_file : Joined<["/", "-"], "lldmap:">;
+def lldmap_file : Joined<["/", "-", "/?", "-?"], "lldmap:">;
 def show_timing : F<"time">;
 def summary : F<"summary">;
 
 //==============================================================================
 // The flags below do nothing. They are defined only for link.exe compatibility.
 //==============================================================================
 
-class QF<string name> : Joined<["/", "-", "-?"], name#":">;
+class QF<string name> : Joined<["/", "-", "/?", "-?"], name#":">;
 
 def ignoreidl : F<"ignoreidl">;
 def nologo : F<"nologo">;