[ms] [llvm-ml] Support purging macro definitions

[epastor]

Summary

Support MASM's PURGE directive.

[thakis]

Can you add a test for the comma variant?

llvm/lib/MC/MCParser/MasmParser.cpp

5565

Why do we accept an optional EndOfStatement after every comma?

[epastor]

Add testing for list invocation of PURGE

llvm/lib/MC/MCParser/MasmParser.cpp

5565

MASM specifies that in list contexts, a trailing comma implies a line continuation... but only in list contexts.

[epastor]

Rebase on HEAD

[epastor]

Rebase to HEAD

llvm/lib/MC/MCParser/COFFMasmParser.cpp

void Initialize(MCAsmParser &Parser) override {
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".nolistif");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".nolistmacro");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>("page");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>("subtitle");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".tfcond");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>("title");
 
     // Macro directives
-    // exitm
     // goto
-    // purge
 
     // Miscellaneous directives
     addDirectiveHandler<&COFFMasmParser::ParseDirectiveAlias>("alias");
     // assume
     // .fpo
     addDirectiveHandler<&COFFMasmParser::ParseDirectiveIncludelib>(
         "includelib");
     // option
void Initialize(MCAsmParser &Parser) override {
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".586");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".586P");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".686");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".686P");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".k3d");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".mmx");
     addDirectiveHandler<&COFFMasmParser::IgnoreDirective>(".xmm");
 
-    // Repeat blocks directives
-    // goto
-
     // Scope directives
     // comm
     // externdef
 
     // Segment directives
     // .alpha (32-bit only, order segments alphabetically)
     // .dosseg (32-bit only, order segments in DOS convention)
     // .seq (32-bit only, order segments sequentially)

llvm/lib/MC/MCParser/MasmParser.cpp

enum DirectiveKind {
     DK_CFI_SIGNAL_FRAME,
     DK_CFI_UNDEFINED,
     DK_CFI_REGISTER,
     DK_CFI_WINDOW_SAVE,
     DK_CFI_B_KEY_FRAME,
     DK_MACRO,
     DK_EXITM,
     DK_ENDM,
-    DK_PURGEM,
+    DK_PURGE,
     DK_ERR,
     DK_ERRB,
     DK_ERRNB,
     DK_ERRDEF,
     DK_ERRNDEF,
     DK_ERRDIF,
     DK_ERRDIFI,
     DK_ERRIDN,
if (DirKind != DK_NO_DIRECTIVE) {
     case DK_CFI_WINDOW_SAVE:
       return parseDirectiveCFIWindowSave();
     case DK_EXITM:
       Info.ExitValue = "";
       return parseDirectiveExitMacro(IDVal, *Info.ExitValue);
     case DK_ENDM:
       Info.ExitValue = "";
       return parseDirectiveEndMacro(IDVal);
-    case DK_PURGEM:
+    case DK_PURGE:
       return parseDirectivePurgeMacro(IDLoc);
     case DK_END:
       return parseDirectiveEnd(IDLoc);
     case DK_ERR:
       return parseDirectiveError(IDLoc);
     case DK_ERRB:
       return parseDirectiveErrorIfb(IDLoc, true);
     case DK_ERRNB:
bool MasmParser::parseDirectiveEndMacro(StringRef Directive) {
 
   // Otherwise, this .endmacro is a stray entry in the file; well formed
   // .endmacro directives are handled during the macro definition parsing.
   return TokError("unexpected '" + Directive + "' in file, "
                                                "no current macro definition");
 }
 
 /// parseDirectivePurgeMacro
-/// ::= .purgem
+/// ::= purge identifier ( , identifier )*
 bool MasmParser::parseDirectivePurgeMacro(SMLoc DirectiveLoc) {
   StringRef Name;
-  SMLoc Loc;
-  if (parseTokenLoc(Loc) ||
-      check(parseIdentifier(Name), Loc,
-            "expected identifier in '.purgem' directive") ||
-      parseToken(AsmToken::EndOfStatement,
-                 "unexpected token in '.purgem' directive"))
+  while (true) {
+    SMLoc NameLoc;
+    if (parseTokenLoc(NameLoc) ||
+        check(parseIdentifier(Name), NameLoc,
+              "expected identifier in 'purge' directive"))
       return true;
 
-  if (!getContext().lookupMacro(Name))
-    return Error(DirectiveLoc, "macro '" + Name + "' is not defined");
-
-  getContext().undefineMacro(Name);
     DEBUG_WITH_TYPE("asm-macros", dbgs()
                                       << "Un-defining macro: " << Name << "\n");
+    if (!getContext().lookupMacro(Name))
+      return Error(NameLoc, "macro '" + Name + "' is not defined");
+    getContext().undefineMacro(Name);
+
+    if (!parseOptionalToken(AsmToken::Comma))
+      break;
+    parseOptionalToken(AsmToken::EndOfStatement);
+  }
+
   return false;
 }
 
 /// parseDirectiveSymbolAttribute
 ///  ::= { ".globl", ".weak", ... } [ identifier ( , identifier )* ]
 bool MasmParser::parseDirectiveSymbolAttribute(MCSymbolAttr Attr) {
   auto parseOp = [&]() -> bool {
     StringRef Name;
void MasmParser::initializeDirectiveKindMap() {
   // DirectiveKindMap[".cfi_signal_frame"] = DK_CFI_SIGNAL_FRAME;
   // DirectiveKindMap[".cfi_undefined"] = DK_CFI_UNDEFINED;
   // DirectiveKindMap[".cfi_register"] = DK_CFI_REGISTER;
   // DirectiveKindMap[".cfi_window_save"] = DK_CFI_WINDOW_SAVE;
   // DirectiveKindMap[".cfi_b_key_frame"] = DK_CFI_B_KEY_FRAME;
   DirectiveKindMap["macro"] = DK_MACRO;
   DirectiveKindMap["exitm"] = DK_EXITM;
   DirectiveKindMap["endm"] = DK_ENDM;
-  // DirectiveKindMap[".purgem"] = DK_PURGEM;
+  DirectiveKindMap["purge"] = DK_PURGE;
   DirectiveKindMap[".err"] = DK_ERR;
   DirectiveKindMap[".errb"] = DK_ERRB;
   DirectiveKindMap[".errnb"] = DK_ERRNB;
   DirectiveKindMap[".errdef"] = DK_ERRDEF;
   DirectiveKindMap[".errndef"] = DK_ERRNDEF;
   DirectiveKindMap[".errdif"] = DK_ERRDIF;
   DirectiveKindMap[".errdifi"] = DK_ERRDIFI;
   DirectiveKindMap[".erridn"] = DK_ERRIDN;

llvm/test/tools/llvm-ml/macro.test

 ; CHECK-NEXT: jmp "??0000"
 
   local_symbol_macro
 ; CHECK: "??0001":
 ; CHECK-NEXT: ret
 ; CHECK-NEXT: jmp "??0001"
 local_symbol_test ENDP
 
+PURGE ambiguous_substitution_macro, local_symbol_macro,
+      optional_parameter_macro
+
+; Redefinition
+local_symbol_macro MACRO
+  LOCAL b
+b: xor eax, eax
+   jmp b
+ENDM
+
+purge_test PROC
+; CHECK-LABEL: purge_test:
+
+  local_symbol_macro
+; CHECK: "??0002":
+; CHECK-NEXT: xor eax, eax
+; CHECK-NEXT: jmp "??0002"
+purge_test ENDP
+
 END