[ms] [llvm-ml] Handle OPTION PROLOGUE/EPILOGUE:NONE

[epastor]

Summary

Since we don't yet implement PROC's PROLOGUE and EPILOGUE support, we can safely ignore the option that disables them.

[thakis]

Test?

[epastor]

Add simple test

[thakis]

Thanks!

llvm/lib/MC/MCParser/COFFMasmParser.cpp

322

nit: no else after return

325

nit: no else after return

333

nit: no else after return

336

nit: no else after return

llvm/test/tools/llvm-ml/option_prologue_epilogue_none.asm

3 ↗

(On Diff #451487)

nit: maybe pRoLoGuE:nOnE and EPILogue:None to test case insensitivity too?

[epastor]

Fixing test

[epastor]

Address nits

[thakis]

llvm/lib/MC/MCParser/COFFMasmParser.cpp

324

no else after return here either

[epastor]

Fix remaining nit

[thakis]

Ship it :)

llvm/lib/MC/MCParser/COFFMasmParser.cpp

bool ParseSectionSwitch(StringRef Section, unsigned Characteristics,
                           SectionKind Kind, StringRef COMDATSymName,
                           COFF::COMDATType Type);
 
   bool ParseDirectiveProc(StringRef, SMLoc);
   bool ParseDirectiveEndProc(StringRef, SMLoc);
   bool ParseDirectiveSegment(StringRef, SMLoc);
   bool ParseDirectiveSegmentEnd(StringRef, SMLoc);
   bool ParseDirectiveIncludelib(StringRef, SMLoc);
+  bool ParseDirectiveOption(StringRef, SMLoc);
 
   bool ParseDirectiveAlias(StringRef, SMLoc);
 
   bool ParseSEHDirectiveAllocStack(StringRef, SMLoc);
   bool ParseSEHDirectiveEndProlog(StringRef, SMLoc);
 
   bool IgnoreDirective(StringRef, SMLoc) {
     while (!getLexer().is(AsmToken::EndOfStatement)) {
void Initialize(MCAsmParser &Parser) override {
     // goto
 
     // Miscellaneous directives
     addDirectiveHandler<&COFFMasmParser::ParseDirectiveAlias>("alias");
     // assume
     // .fpo
     addDirectiveHandler<&COFFMasmParser::ParseDirectiveIncludelib>(
         "includelib");
-    // option
+    addDirectiveHandler<&COFFMasmParser::ParseDirectiveOption>("option");
     // popcontext
     // pushcontext
     // .safeseh
 
     // Procedure directives
     addDirectiveHandler<&COFFMasmParser::ParseDirectiveEndProc>("endp");
     // invoke (32-bit only)
     addDirectiveHandler<&COFFMasmParser::ParseDirectiveProc>("proc");
getStreamer().switchSection(getContext().getCOFFSection(
       ".drectve", Flags, Kind, "", (COFF::COMDATType)(0)));
   getStreamer().emitBytes("/DEFAULTLIB:");
   getStreamer().emitBytes(Lib);
   getStreamer().emitBytes(" ");
   getStreamer().popSection();
   return false;
 }
 
+/// ParseDirectiveOption
+///  ::= "option" option-list
+bool COFFMasmParser::ParseDirectiveOption(StringRef Directive, SMLoc Loc) {
+  auto parseOption = [&]() -> bool {
+    StringRef Option;
+    if (getParser().parseIdentifier(Option))
+      return TokError("expected identifier for option name");
+    if (Option.equals_insensitive("prologue")) {
+      StringRef MacroId;
+      if (parseToken(AsmToken::Colon) || getParser().parseIdentifier(MacroId))
+        return TokError("expected :macroId after OPTION PROLOGUE");
+      if (MacroId.equals_insensitive("none")) {
+        // Since we currently don't implement prologues/epilogues, NONE is our
+        // default.
+        return false;
+      } else {
+        return TokError("OPTION PROLOGUE is currently unsupported");
+      }
+    } else if (Option.equals_insensitive("epilogue")) {
+      StringRef MacroId;
+      if (parseToken(AsmToken::Colon) || getParser().parseIdentifier(MacroId))
+        return TokError("expected :macroId after OPTION EPILOGUE");
+      if (MacroId.equals_insensitive("none")) {
+        // Since we currently don't implement prologues/epilogues, NONE is our
+        // default.
+        return false;
+      } else {
+        return TokError("OPTION EPILOGUE is currently unsupported");
+      }
+    } else {
+      return TokError("OPTION '" + Option + "' is currently unsupported");
+    }
+  };
+
+  if (parseMany(parseOption))
+    return addErrorSuffix(" in OPTION directive");
+  return false;
+}
+
 /// ParseDirectiveProc
 /// TODO(epastor): Implement parameters and other attributes.
 ///  ::= label "proc" [[distance]]
 ///          statements
 ///      label "endproc"
 bool COFFMasmParser::ParseDirectiveProc(StringRef Directive, SMLoc Loc) {
   StringRef Label;
   if (getParser().parseIdentifier(Label))