[ms] [llvm-ml] Implement the statement expansion operator

[epastor]

Summary

If prefaced with a %, expand text macros and macro functions in any statement.

Also, prevent expanding text macros in the message of an ECHO directive unless expanded explicitly by the statement expansion operator.

[epastor]

Rebase on HEAD

[epastor]

Rebase on parent

[thakis]

Looks like there's no coverage for expanding statements that aren't the echo special case - - could you add coverage for that too? Other than that, lg!

llvm/include/llvm/MC/MCAsmMacro.h

147

IsFunction

llvm/lib/MC/MCParser/MasmParser.cpp

5565

IsMacroFunction

[epastor]

Add a test case covering the lack of impact on typical statements

[epastor]

Rebase on parent

[epastor]

In D89740#2416458, @thakis wrote:

Looks like there's no coverage for expanding statements that aren't the echo special case - - could you add coverage for that too? Other than that, lg!

Oddly enough, MASM documentation suggests no use for this form except for ECHO and similar special cases, as strings are generally meant to be lexed.

[thakis]

llvm/test/tools/llvm-ml/macro_function.test

106 ↗

(On Diff #307686)

(this looks the same as the test in https://reviews.llvm.org/D89741 ; i'm guessing it belongs over there and not to this patch here.)

[epastor]

Remove unrelated test update.

[epastor]

Rebase to HEAD

[epastor]

Fix typo in test

llvm/include/llvm/MC/MCAsmMacro.h

 };
 
 typedef std::vector<MCAsmMacroParameter> MCAsmMacroParameters;
 struct MCAsmMacro {
   StringRef Name;
   StringRef Body;
   MCAsmMacroParameters Parameters;
   std::vector<std::string> Locals;
+  bool IsFunction = false;
 
 public:
   MCAsmMacro(StringRef N, StringRef B, MCAsmMacroParameters P)
       : Name(N), Body(B), Parameters(std::move(P)) {}
   MCAsmMacro(StringRef N, StringRef B, MCAsmMacroParameters P,
-             std::vector<std::string> L)
-      : Name(N), Body(B), Parameters(std::move(P)), Locals(std::move(L)) {}
+             std::vector<std::string> L, bool F)
+      : Name(N), Body(B), Parameters(std::move(P)), Locals(std::move(L)),
+        IsFunction(F) {}
 
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
   void dump() const { dump(dbgs()); }
   LLVM_DUMP_METHOD void dump(raw_ostream &OS) const;
 #endif
 };
 } // namespace llvm
 
 #endif

llvm/lib/MC/MCParser/MasmParser.cpp

parseMacroArgument(const MCAsmMacroParameter *MP, MCAsmMacroArgument &MA,
                      AsmToken::TokenKind EndTok = AsmToken::EndOfStatement);
 
   /// Parse all macro arguments for a given macro.
   bool
   parseMacroArguments(const MCAsmMacro *M, MCAsmMacroArguments &A,
                       AsmToken::TokenKind EndTok = AsmToken::EndOfStatement);
 
   void printMacroInstantiations();
+
+  bool expandStatement(SMLoc Loc);
+
   void printMessage(SMLoc Loc, SourceMgr::DiagKind Kind, const Twine &Msg,
                     SMRange Range = None) const {
     ArrayRef<SMRange> Ranges(Range);
     SrcMgr.PrintMessage(Loc, Kind, Msg, Ranges);
   }
   static void DiagHandler(const SMDiagnostic &Diag, void *Context);
 
   bool lookUpField(const StructInfo &Structure, StringRef Member,
private:
   ///
   /// \param InBuffer If not 0, should be the known buffer id that contains the
   /// location.
   void jumpToLoc(SMLoc Loc, unsigned InBuffer = 0,
                  bool EndStatementAtEOF = true);
 
   /// Parse up to a token of kind \p EndTok and return the contents from the
   /// current token up to (but not including) this token; the current token on
-  /// exit will be either this kind or EOF.
-  StringRef parseStringTo(AsmToken::TokenKind EndTok);
+  /// exit will be either this kind or EOF. Reads through instantiated macro
+  /// functions and text macros.
+  SmallVector<StringRef, 1> parseStringRefsTo(AsmToken::TokenKind EndTok);
+  std::string parseStringTo(AsmToken::TokenKind EndTok);
 
   /// Parse up to the end of statement and return the contents from the current
   /// token until the end of the statement; the current token on exit will be
   /// either the EndOfStatement or EOF.
-  StringRef parseStringToEndOfStatement() override {
-    return parseStringTo(AsmToken::EndOfStatement);
-  }
+  StringRef parseStringToEndOfStatement() override;
 
   bool parseTextItem(std::string &Data);
 
   unsigned getBinOpPrecedence(AsmToken::TokenKind K,
                               MCBinaryExpr::Opcode &Kind);
 
   bool parseBinOpRHS(unsigned Precedence, const MCExpr *&Res, SMLoc &EndLoc);
   bool parseParenExpr(const MCExpr *&Res, SMLoc &EndLoc);
if (getTok().is(AsmToken::EndOfStatement)) {
     if (!getTok().getString().empty() && getTok().getString().front() != '\n' &&
         getTok().getString().front() != '\r' && MAI.preserveAsmComments())
       Out.addExplicitComment(Twine(getTok().getString()));
   }
 
   const AsmToken *tok = &Lexer.Lex();
 
   while (tok->is(AsmToken::Identifier)) {
-    auto it = Variables.find(tok->getIdentifier());
+    auto it = Variables.find(tok->getIdentifier().lower());
+    const llvm::MCAsmMacro *M =
+        getContext().lookupMacro(tok->getIdentifier().lower());
     if (it != Variables.end() && it->second.IsText) {
+      // This is a textmacro; expand it in place.
       std::unique_ptr<MemoryBuffer> Instantiation =
           MemoryBuffer::getMemBufferCopy(it->second.TextValue,
                                          "<instantiation>");
 
       // Jump to the macro instantiation and prime the lexer.
       CurBuffer = SrcMgr.AddNewSourceBuffer(std::move(Instantiation),
                                             getTok().getEndLoc());
       Lexer.setBuffer(SrcMgr.getMemoryBuffer(CurBuffer)->getBuffer(), nullptr,
                       /*EndStatementAtEOF=*/false);
       EndStatementAtEOFStack.push_back(false);
       tok = &Lexer.Lex();
+    } else if (M && M->IsFunction && Lexer.peekTok().is(AsmToken::LParen)) {
+      // This is a macro function invocation; expand it in place.
+      const AsmToken MacroTok = *tok;
+      tok = &Lexer.Lex();
+      if (handleMacroInvocation(M, MacroTok.getLoc())) {
+        Lexer.UnLex(AsmToken(AsmToken::Error, MacroTok.getIdentifier()));
+        tok = &Lexer.Lex();
+      }
+      continue;
     } else {
       break;
     }
   }
 
   // Parse comments here to be deferred until end of next statement.
   while (tok->is(AsmToken::Comment)) {
     if (MAI.preserveAsmComments())
if (!Sec->getBeginSymbol()) {
       Sec->setBeginSymbol(SectionStartSym);
     }
     bool InsertResult = getContext().addGenDwarfSection(Sec);
     assert(InsertResult && ".text section should not have debug info yet");
     (void)InsertResult;
   }
 
   // While we have input, parse each statement.
-  while (Lexer.isNot(AsmToken::Eof)) {
+  while (Lexer.isNot(AsmToken::Eof) ||
+         SrcMgr.getParentIncludeLoc(CurBuffer) != SMLoc()) {
+    // Skip through the EOF at the end of an inclusion.
+    if (Lexer.is(AsmToken::Eof))
+      Lex();
+
     ParseStatementInfo Info(&AsmStrRewrites);
     bool Parsed = parseStatement(Info, nullptr);
 
     // If we have a Lexer Error we are on an Error Token. Load in Lexer Error
     // for printing ErrMsg via Lex() only if no (presumably better) parser error
     // exists.
     if (Parsed && !hasPendingError() && Lexer.getTok().is(AsmToken::Error)) {
       Lex();
if (!ParsingMSInlineAsm && !getStreamer().getCurrentSectionOnly()) {
     return Error(getTok().getLoc(),
                  "expected section directive before assembly directive");
   }
   return false;
 }
 
 /// Throw away the rest of the line for testing purposes.
 void MasmParser::eatToEndOfStatement() {
-  while (Lexer.isNot(AsmToken::EndOfStatement) && Lexer.isNot(AsmToken::Eof))
+  while (Lexer.isNot(AsmToken::EndOfStatement)) {
+    if (Lexer.is(AsmToken::Eof)) {
+      SMLoc ParentIncludeLoc = SrcMgr.getParentIncludeLoc(CurBuffer);
+      if (ParentIncludeLoc == SMLoc()) {
+        break;
+      }
+
+      EndStatementAtEOFStack.pop_back();
+      jumpToLoc(ParentIncludeLoc, 0, EndStatementAtEOFStack.back());
+    }
+
     Lexer.Lex();
+  }
 
   // Eat EOL.
   if (Lexer.is(AsmToken::EndOfStatement))
     Lexer.Lex();
 }
 
-StringRef MasmParser::parseStringTo(AsmToken::TokenKind EndTok) {
+SmallVector<StringRef, 1>
+MasmParser::parseStringRefsTo(AsmToken::TokenKind EndTok) {
+  SmallVector<StringRef, 1> Refs;
+  const char *Start = getTok().getLoc().getPointer();
+  while (Lexer.isNot(EndTok)) {
+    if (Lexer.is(AsmToken::Eof)) {
+      SMLoc ParentIncludeLoc = SrcMgr.getParentIncludeLoc(CurBuffer);
+      if (ParentIncludeLoc == SMLoc()) {
+        break;
+      }
+      Refs.emplace_back(Start, getTok().getLoc().getPointer() - Start);
+
+      EndStatementAtEOFStack.pop_back();
+      jumpToLoc(ParentIncludeLoc, 0, EndStatementAtEOFStack.back());
+      Lexer.Lex();
+      Start = getTok().getLoc().getPointer();
+    } else {
+      Lexer.Lex();
+    }
+  }
+  Refs.emplace_back(Start, getTok().getLoc().getPointer() - Start);
+  return Refs;
+}
+
+std::string MasmParser::parseStringTo(AsmToken::TokenKind EndTok) {
+  SmallVector<StringRef, 1> Refs = parseStringRefsTo(EndTok);
+  std::string Str;
+  for (StringRef S : Refs) {
+    Str.append(S.str());
+  }
+  return Str;
+}
+
+StringRef MasmParser::parseStringToEndOfStatement() {
   const char *Start = getTok().getLoc().getPointer();
 
-  while (Lexer.isNot(EndTok) && Lexer.isNot(AsmToken::Eof))
+  while (Lexer.isNot(AsmToken::EndOfStatement) && Lexer.isNot(AsmToken::Eof))
     Lexer.Lex();
 
   const char *End = getTok().getLoc().getPointer();
   return StringRef(Start, End - Start);
 }
 
 /// Parse a paren expression and return it.
 /// NOTE: This assumes the leading '(' has already been consumed.
bool MasmParser::parseBracketExpr(const MCExpr *&Res, SMLoc &EndLoc) {
   EndLoc = getTok().getEndLoc();
   if (parseToken(AsmToken::RBrac, "expected ']' in brackets expression"))
     return true;
   return false;
 }
 
 /// Parse a primary expression and return it.
 ///  primaryexpr ::= (parenexpr
-///  primaryexpr ::= macro_function "(" macro_arguments ")"
 ///  primaryexpr ::= symbol
 ///  primaryexpr ::= number
 ///  primaryexpr ::= '.'
 ///  primaryexpr ::= ~,+,-,'not' primaryexpr
 ///  primaryexpr ::= string
 ///          (a string is interpreted as a 64-bit number in big-endian base-256)
 bool MasmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc,
                                   AsmTypeInfo *TypeInfo) {
case AsmToken::Identifier: {
     }
     // Parse named bitwise negation.
     if (Identifier.equals_lower("not")) {
       if (parsePrimaryExpr(Res, EndLoc, nullptr))
         return true;
       Res = MCUnaryExpr::createNot(Res, getContext(), FirstTokenLoc);
       return false;
     }
-    // Parse macro function invocation.
-    if (const MCAsmMacro *M = getContext().lookupMacro(Identifier)) {
-      if (handleMacroInvocation(M, FirstTokenLoc))
-        return true;
-      return parsePrimaryExpr(Res, EndLoc, nullptr);
-    }
     // Parse symbol variant.
     std::pair<StringRef, StringRef> Split;
     if (!MAI.useParensForSymbolVariant()) {
       if (FirstTokenKind == AsmToken::String) {
         if (Lexer.is(AsmToken::At)) {
           Lex(); // eat @
           SMLoc AtLoc = getLexer().getLoc();
           StringRef VName;
if (TokPrec < NextTokPrec && parseBinOpRHS(TokPrec + 1, RHS, EndLoc))
       return true;
 
     // Merge LHS and RHS according to operator.
     Res = MCBinaryExpr::create(Kind, Res, RHS, getContext(), StartLoc);
   }
 }
 
 /// ParseStatement:
+///   ::= % statement
 ///   ::= EndOfStatement
 ///   ::= Label* Directive ...Operands... EndOfStatement
 ///   ::= Label* Identifier OperandList* EndOfStatement
 bool MasmParser::parseStatement(ParseStatementInfo &Info,
                                 MCAsmParserSemaCallback *SI) {
   assert(!hasPendingError() && "parseStatement started with pending error");
   // Eat initial spaces and comments.
   while (Lexer.is(AsmToken::Space))
     Lex();
   if (Lexer.is(AsmToken::EndOfStatement)) {
     // If this is a line comment we can drop it safely.
     if (getTok().getString().empty() || getTok().getString().front() == '\r' ||
         getTok().getString().front() == '\n')
       Out.AddBlankLine();
     Lex();
     return false;
   }
+
+  // If preceded by an expansion operator, first expand all text macros and
+  // macro functions.
+  if (getTok().is(AsmToken::Percent)) {
+    SMLoc ExpansionLoc = getTok().getLoc();
+    if (parseToken(AsmToken::Percent) || expandStatement(ExpansionLoc))
+      return true;
+  }
+
   // Statements always start with an identifier, unless we're dealing with a
   // processor directive (.386, .686, etc.) that lexes as a real.
   AsmToken ID = getTok();
   SMLoc IDLoc = ID.getLoc();
   StringRef IDVal;
   int64_t LocalLabelVal = -1;
   if (Lexer.is(AsmToken::HashDirective))
     return parseCppHashLineFilenameComment(IDLoc);
if (Lexer.is(AsmToken::Integer)) {
     Lex();
     IDVal = "*";
   } else if (Lexer.is(AsmToken::Real)) {
     // Treat ".<number>" as a valid identifier in this context.
     IDVal = getTok().getString();
     Lex(); // always eat a token
     if (!IDVal.startswith("."))
       return Error(IDLoc, "unexpected token at start of statement");
+  } else if (Lexer.is(AsmToken::Identifier) &&
+             getTok().getString().equals_lower("echo")) {
+    // Intercept echo early to avoid lexical substitution in its message, and
+    // delegate all handling to the appropriate function.
+    return parseDirectiveEcho();
   } else if (parseIdentifier(IDVal)) {
     if (!TheCondState.Ignore) {
       Lex(); // always eat a token
       return Error(IDLoc, "unexpected token at start of statement");
     }
     IDVal = "";
   }
 
if (LocalLabelVal == -1) {
       Sym = getContext().getOrCreateSymbol(IDVal);
     } else
       Sym = Ctx.createDirectionalLocalSymbol(LocalLabelVal);
     // End of Labels should be treated as end of line for lexing
     // purposes but that information is not available to the Lexer who
     // does not understand Labels. This may cause us to see a Hash
     // here instead of a preprocessor line comment.
     if (getTok().is(AsmToken::Hash)) {
-      StringRef CommentStr = parseStringToEndOfStatement();
+      std::string CommentStr = parseStringTo(AsmToken::EndOfStatement);
       Lexer.Lex();
       Lexer.UnLex(AsmToken(AsmToken::EndOfStatement, CommentStr));
     }
 
     // Consume any end of statement token, if present, to avoid spurious
     // AddBlankLine calls().
     if (getTok().is(AsmToken::EndOfStatement)) {
       Lex();
case AsmToken::Colon: {
     return false;
   }
 
   default: // Normal instruction or directive.
     break;
   }
 
   // If macros are enabled, check to see if this is a macro instantiation.
-  if (const MCAsmMacro *M = getContext().lookupMacro(IDVal)) {
+  if (const MCAsmMacro *M = getContext().lookupMacro(IDVal.lower())) {
     return handleMacroEntry(M, IDLoc);
   }
 
   // Otherwise, we have a normal instruction or directive.
 
   if (DirKind != DK_NO_DIRECTIVE) {
     // There are several entities interested in parsing directives:
     //
case DK_ERRIDNI:
       return parseDirectiveErrorIfidn(IDLoc, /*ExpectEqual=*/true,
                                       /*CaseInsensitive=*/true);
     case DK_ERRE:
       return parseDirectiveErrorIfe(IDLoc, true);
     case DK_ERRNZ:
       return parseDirectiveErrorIfe(IDLoc, false);
     case DK_RADIX:
       return parseDirectiveRadix(IDLoc);
-    case DK_ECHO:
-      return parseDirectiveEcho();
     }
 
     return Error(IDLoc, "unknown directive");
   }
 
   // We also check if this is allocating memory with user-defined type.
   auto IDIt = Structs.find(IDVal.lower());
   if (IDIt != Structs.end())
if (Pos == End)
       break;
 
     unsigned I = Pos;
     bool InitialAmpersand = (Body[I] == '&');
     if (InitialAmpersand) {
       ++I;
       ++Pos;
     }
-    while (isMacroParameterChar(Body[I]) && I + 1 != End)
+    while (I < End && isMacroParameterChar(Body[I]))
       ++I;
 
     const char *Begin = Body.data() + Pos;
     StringRef Argument(Begin, I - Pos);
     unsigned Index = 0;
 
     for (; Index < NParameters; ++Index)
       if (Parameters[Index].Name == Argument)

 
 } // end anonymous namespace
 
 bool MasmParser::parseMacroArgument(const MCAsmMacroParameter *MP,
                                     MCAsmMacroArgument &MA,
                                     AsmToken::TokenKind EndTok) {
   if (MP && MP->Vararg) {
     if (Lexer.isNot(EndTok)) {
-      StringRef Str = parseStringTo(EndTok);
-      MA.emplace_back(AsmToken::String, Str);
+      SmallVector<StringRef, 1> Str = parseStringRefsTo(EndTok);
+      for (StringRef S : Str) {
+        MA.emplace_back(AsmToken::String, S);
+      }
     }
     return false;
   }
+
   SMLoc StrLoc = Lexer.getLoc(), EndLoc;
   if (Lexer.is(AsmToken::Less) && isAngleBracketString(StrLoc, EndLoc)) {
     const char *StrChar = StrLoc.getPointer() + 1;
     const char *EndChar = EndLoc.getPointer() - 1;
     jumpToLoc(EndLoc, CurBuffer, EndStatementAtEOFStack.back());
     /// Eat from '<' to '>'.
     Lex();
     MA.emplace_back(AsmToken::String, StringRef(StrChar, EndChar - StrChar));
if (Lexer.is(AsmToken::Eof) || Lexer.is(AsmToken::Equal))
       return TokError("unexpected token");
 
     if (ParenLevel == 0) {
       if (Lexer.is(AsmToken::Comma))
         break;
 
       if (Lexer.is(AsmToken::Space)) {
         SpaceEaten = true;
-        Lexer.Lex(); // Eat spaces.
+        Lex(); // Eat spaces.
       }
 
       // Spaces can delimit parameters, but could also be part an expression.
       // If the token after a space is an operator, add the token and the next
       // one into this argument
       if (!IsDarwin) {
         if (isOperator(Lexer.getKind()) && Lexer.isNot(EndTok)) {
           MA.push_back(getTok());
-          Lexer.Lex();
+          Lex();
 
           // Whitespace after an operator can be ignored.
           if (Lexer.is(AsmToken::Space))
-            Lexer.Lex();
+            Lex();
 
           continue;
         }
       }
       if (SpaceEaten)
         break;
     }
 
     // handleMacroEntry relies on not advancing the lexer here
     // to be able to fill in the remaining default parameter values
     if (Lexer.is(EndTok) && (EndTok != AsmToken::RParen || ParenLevel == 0))
       break;
 
     // Adjust the current parentheses level.
     if (Lexer.is(AsmToken::LParen))
       ++ParenLevel;
     else if (Lexer.is(AsmToken::RParen) && ParenLevel)
       --ParenLevel;
 
     // Append the token to the current argument list.
     MA.push_back(getTok());
-    Lexer.Lex();
+    Lex();
   }
 
   if (ParenLevel != 0)
     return TokError("unbalanced parentheses in argument");
 
   if (MA.empty() && MP) {
     if (MP->Required) {
       return TokError("missing value for required parameter '" + MP->Name +
void MasmParser::handleMacroExit() {
   Lex();
 
   // Pop the instantiation entry.
   delete ActiveMacros.back();
   ActiveMacros.pop_back();
 }
 
 bool MasmParser::handleMacroInvocation(const MCAsmMacro *M, SMLoc NameLoc) {
+  if (!M->IsFunction)
+    return Error(NameLoc, "cannot invoke macro procedure as function");
+
   if (parseToken(AsmToken::LParen, "invoking macro function '" + M->Name +
                                        "' requires arguments in parentheses") ||
       handleMacroEntry(M, NameLoc, AsmToken::RParen))
     return true;
 
   // Parse all statements in the macro, retrieving the exit value when it ends.
   std::string ExitValue;
   SmallVector<AsmRewrite, 4> AsmStrRewrites;
bool MasmParser::parseTextItem(std::string &Data) {
   case AsmToken::LessEqual:
   case AsmToken::LessLess:
   case AsmToken::LessGreater:
     return parseAngleBracketString(Data);
   case AsmToken::Identifier: {
     StringRef ID;
     if (parseIdentifier(ID))
       return true;
+    Data = ID.str();
 
     auto it = Variables.find(ID);
     if (it == Variables.end())
       return true;
 
+    while (it != Variables.end()) {
       const Variable &Var = it->second;
       if (!Var.IsText)
         return true;
       Data = Var.TextValue;
+      it = Variables.find(Data);
+    }
     return false;
   }
   }
   llvm_unreachable("unhandled token kind");
 }
 
 /// parseDirectiveAscii:
 ///   ::= ( .ascii | .asciz | .string ) [ "string" ( , "string" )* ]
while (true) {
         break;
       parseOptionalToken(AsmToken::EndOfStatement);
     }
   }
 
   // Consuming deferred text, so use Lexer.Lex to ignore Lexing Errors.
   AsmToken EndToken, StartToken = getTok();
   unsigned MacroDepth = 0;
+  bool IsMacroFunction = false;
   // Lex the macro definition.
   while (true) {
     // Ignore Lexing errors in macros.
     while (Lexer.is(AsmToken::Error)) {
       Lexer.Lex();
     }
 
     // Check whether we have reached the end of the file.
     if (getLexer().is(AsmToken::Eof))
       return Error(NameLoc, "no matching 'endm' in definition");
 
-    // Otherwise, check whether we have reach the 'endm'.
+    // Otherwise, check whether we have reached the 'endm'... and determine if
+    // this is a macro function.
     if (getLexer().is(AsmToken::Identifier)) {
       if (getTok().getIdentifier().equals_lower("endm")) {
         if (MacroDepth == 0) { // Outermost macro.
           EndToken = getTok();
           Lexer.Lex();
           if (getLexer().isNot(AsmToken::EndOfStatement))
             return TokError("unexpected token in '" + EndToken.getIdentifier() +
                             "' directive");
           break;
         } else {
           // Otherwise we just found the end of an inner macro.
           --MacroDepth;
         }
+      } else if (getTok().getIdentifier().equals_lower("exitm")) {
+        if (MacroDepth == 0 &&
+            getLexer().peekTok().isNot(AsmToken::EndOfStatement)) {
+          IsMacroFunction = true;
+        }
       } else if (isMacroLikeDirective()) {
         // We allow nested macros. Those aren't instantiated until the
         // outermost macro is expanded so just ignore them for now.
         ++MacroDepth;
       }
     }
 
     // Otherwise, scan til the end of the statement.
     eatToEndOfStatement();
   }
 
-  if (getContext().lookupMacro(Name)) {
+  if (getContext().lookupMacro(Name.lower())) {
     return Error(NameLoc, "macro '" + Name + "' is already defined");
   }
 
   const char *BodyStart = StartToken.getLoc().getPointer();
   const char *BodyEnd = EndToken.getLoc().getPointer();
   StringRef Body = StringRef(BodyStart, BodyEnd - BodyStart);
-  MCAsmMacro Macro(Name, Body, std::move(Parameters), std::move(Locals));
+  MCAsmMacro Macro(Name, Body, std::move(Parameters), std::move(Locals),
+                   IsMacroFunction);
   DEBUG_WITH_TYPE("asm-macros", dbgs() << "Defining new macro:\n";
                   Macro.dump());
   getContext().defineMacro(Name, std::move(Macro));
   return false;
 }
 
 /// parseDirectiveExitMacro
 /// ::= "exitm" [textitem]
while (true) {
     SMLoc NameLoc;
     if (parseTokenLoc(NameLoc) ||
         check(parseIdentifier(Name), NameLoc,
               "expected identifier in 'purge' directive"))
       return true;
 
     DEBUG_WITH_TYPE("asm-macros", dbgs()
                                       << "Un-defining macro: " << Name << "\n");
-    if (!getContext().lookupMacro(Name))
+    if (!getContext().lookupMacro(Name.lower()))
       return Error(NameLoc, "macro '" + Name + "' is not defined");
-    getContext().undefineMacro(Name);
+    getContext().undefineMacro(Name.lower());
 
     if (!parseOptionalToken(AsmToken::Comma))
       break;
     parseOptionalToken(AsmToken::EndOfStatement);
   }
 
   return false;
 }
bool MasmParser::parseDirectiveComm(bool IsLocal) {
   return false;
 }
 
 /// parseDirectiveComment
 ///  ::= comment delimiter [[text]]
 ///              [[text]]
 ///              [[text]] delimiter [[text]]
 bool MasmParser::parseDirectiveComment(SMLoc DirectiveLoc) {
-  StringRef FirstLine = parseStringToEndOfStatement();
+  std::string FirstLine = parseStringTo(AsmToken::EndOfStatement);
   size_t DelimiterEnd = FirstLine.find_first_of("\b\t\v\f\r\x1A ");
-  StringRef Delimiter = FirstLine.take_front(DelimiterEnd);
+  StringRef Delimiter = StringRef(FirstLine).take_front(DelimiterEnd);
   if (Delimiter.empty())
     return Error(DirectiveLoc, "no delimiter in 'comment' directive");
   do {
     if (getTok().is(AsmToken::Eof))
       return Error(DirectiveLoc, "unmatched delimiter in 'comment' directive");
     Lex();  // eat end of statement
-  } while (!parseStringToEndOfStatement().contains(Delimiter));
+  } while (
+      !StringRef(parseStringTo(AsmToken::EndOfStatement)).contains(Delimiter));
   return parseToken(AsmToken::EndOfStatement,
                     "unexpected token in 'comment' directive");
 }
 
 /// parseDirectiveInclude
 ///  ::= include <filename>
 ///    | include filename
 bool MasmParser::parseDirectiveInclude() {
   // Allow the strings to have escaped octal character sequence.
   std::string Filename;
   SMLoc IncludeLoc = getTok().getLoc();
 
   if (!parseAngleBracketString(Filename))
-    Filename = parseStringToEndOfStatement().str();
+    Filename = parseStringTo(AsmToken::EndOfStatement);
   if (check(!Filename.empty(), "missing filename in 'include' directive") ||
       check(getTok().isNot(AsmToken::EndOfStatement),
             "unexpected token in 'include' directive") ||
       // Attempt to switch the lexer to the included file before consuming the
       // end of statement to avoid losing it when we switch.
       check(enterIncludeFile(Filename), IncludeLoc,
             "Could not find include file '" + Filename + "'"))
     return true;

 bool MasmParser::parseDirectiveError(SMLoc DirectiveLoc) {
   if (!TheCondStack.empty()) {
     if (TheCondStack.back().Ignore) {
       eatToEndOfStatement();
       return false;
     }
   }
 
-  StringRef Message = ".err directive invoked in source file";
+  std::string Message = ".err directive invoked in source file";
   if (Lexer.isNot(AsmToken::EndOfStatement))
-    Message = parseStringToEndOfStatement();
+    Message = parseStringTo(AsmToken::EndOfStatement);
   Lex();
 
   return Error(DirectiveLoc, Message);
 }
 
 /// parseDirectiveErrorIfb
 ///   ::= .errb textitem[, message]
 bool MasmParser::parseDirectiveErrorIfb(SMLoc DirectiveLoc, bool ExpectBlank) {
   if (!TheCondStack.empty()) {
     if (TheCondStack.back().Ignore) {
       eatToEndOfStatement();
       return false;
     }
   }
 
   std::string Text;
   if (parseTextItem(Text))
     return Error(getTok().getLoc(), "missing text item in '.errb' directive");
 
-  StringRef Message = ".errb directive invoked in source file";
+  std::string Message = ".errb directive invoked in source file";
   if (Lexer.isNot(AsmToken::EndOfStatement)) {
     if (parseToken(AsmToken::Comma))
       return addErrorSuffix(" in '.errb' directive");
-    Message = parseStringToEndOfStatement();
+    Message = parseStringTo(AsmToken::EndOfStatement);
   }
   Lex();
 
   if (Text.empty() == ExpectBlank)
     return Error(DirectiveLoc, Message);
   return false;
 }
 
if (!IsDefined) {
     if (Variables.find(Name) != Variables.end()) {
       IsDefined = true;
     } else {
       MCSymbol *Sym = getContext().lookupSymbol(Name);
       IsDefined = (Sym && !Sym->isUndefined(false));
     }
   }
 
-  StringRef Message = ".errdef directive invoked in source file";
+  std::string Message = ".errdef directive invoked in source file";
   if (Lexer.isNot(AsmToken::EndOfStatement)) {
     if (parseToken(AsmToken::Comma))
       return addErrorSuffix(" in '.errdef' directive");
-    Message = parseStringToEndOfStatement();
+    Message = parseStringTo(AsmToken::EndOfStatement);
   }
   Lex();
 
   if (IsDefined == ExpectDefined)
     return Error(DirectiveLoc, Message);
   return false;
 }
 
bool MasmParser::parseDirectiveErrorIfidn(SMLoc DirectiveLoc, bool ExpectEqual,
   Lex();
 
   if (parseTextItem(String2)) {
     if (ExpectEqual)
       return TokError("expected string parameter for '.erridn' directive");
     return TokError("expected string parameter for '.errdif' directive");
   }
 
-  StringRef Message;
+  std::string Message;
   if (ExpectEqual)
     Message = ".erridn directive invoked in source file";
   else
     Message = ".errdif directive invoked in source file";
   if (Lexer.isNot(AsmToken::EndOfStatement)) {
     if (parseToken(AsmToken::Comma))
       return addErrorSuffix(" in '.erridn' directive");
-    Message = parseStringToEndOfStatement();
+    Message = parseStringTo(AsmToken::EndOfStatement);
   }
   Lex();
 
   if (CaseInsensitive)
     TheCondState.CondMet =
         ExpectEqual == (StringRef(String1).equals_lower(String2));
   else
     TheCondState.CondMet = ExpectEqual == (String1 == String2);
if (TheCondStack.back().Ignore) {
       return false;
     }
   }
 
   int64_t ExprValue;
   if (parseAbsoluteExpression(ExprValue))
     return addErrorSuffix(" in '.erre' directive");
 
-  StringRef Message = ".erre directive invoked in source file";
+  std::string Message = ".erre directive invoked in source file";
   if (Lexer.isNot(AsmToken::EndOfStatement)) {
     if (parseToken(AsmToken::Comma))
       return addErrorSuffix(" in '.erre' directive");
-    Message = parseStringToEndOfStatement();
+    Message = parseStringTo(AsmToken::EndOfStatement);
   }
   Lex();
 
   if ((ExprValue == 0) == ExpectZero)
     return Error(DirectiveLoc, Message);
   return false;
 }
 
MCAsmMacro *MasmParser::parseMacroLikeBody(SMLoc DirectiveLoc) {
   const char *BodyEnd = EndToken.getLoc().getPointer();
   StringRef Body = StringRef(BodyStart, BodyEnd - BodyStart);
 
   // We Are Anonymous.
   MacroLikeBodies.emplace_back(StringRef(), Body, MCAsmMacroParameters());
   return &MacroLikeBodies.back();
 }
 
+bool MasmParser::expandStatement(SMLoc Loc) {
+  std::string Body = parseStringTo(AsmToken::EndOfStatement);
+  SMLoc EndLoc = getTok().getLoc();
+
+  MCAsmMacroParameters Parameters;
+  MCAsmMacroArguments Arguments;
+  for (const auto &V : Variables) {
+    const Variable &Var = V.getValue();
+    if (Var.IsText) {
+      Parameters.emplace_back();
+      Arguments.emplace_back();
+      MCAsmMacroParameter &P = Parameters.back();
+      MCAsmMacroArgument &A = Arguments.back();
+      P.Name = Var.Name;
+      P.Required = true;
+      A.push_back(AsmToken(AsmToken::String, Var.TextValue));
+    }
+  }
+  MacroLikeBodies.emplace_back(StringRef(), Body, Parameters);
+  MCAsmMacro M = MacroLikeBodies.back();
+
+  // Expand the statement in a new buffer.
+  SmallString<80> Buf;
+  raw_svector_ostream OS(Buf);
+  if (expandMacro(OS, M.Body, M.Parameters, Arguments, M.Locals, EndLoc))
+    return true;
+  std::unique_ptr<MemoryBuffer> Expansion =
+      MemoryBuffer::getMemBufferCopy(OS.str(), "<expansion>");
+
+  // Jump to the expanded statement and prime the lexer.
+  CurBuffer = SrcMgr.AddNewSourceBuffer(std::move(Expansion), EndLoc);
+  Lexer.setBuffer(SrcMgr.getMemoryBuffer(CurBuffer)->getBuffer());
+  EndStatementAtEOFStack.push_back(false);
+  Lex();
+  return false;
+}
+
 void MasmParser::instantiateMacroLikeBody(MCAsmMacro *M, SMLoc DirectiveLoc,
                                           raw_svector_ostream &OS) {
   instantiateMacroLikeBody(M, DirectiveLoc, /*ExitLoc=*/getTok().getLoc(), OS);
 }
 void MasmParser::instantiateMacroLikeBody(MCAsmMacro *M, SMLoc DirectiveLoc,
                                           SMLoc ExitLoc,
                                           raw_svector_ostream &OS) {
   OS << "endm\n";
if (check(parseIdentifier(Parameter.Name),
             "expected identifier in '" + Directive + "' directive") ||
       parseToken(AsmToken::Comma,
                  "expected comma in '" + Directive + "' directive"))
     return true;
   if (parseAngleBracketString(Argument)) {
     // Match ml64.exe; treat all characters to end of statement as a string,
     // ignoring comment markers, then discard anything following a space (using
     // the C locale).
-    Argument = parseStringToEndOfStatement().str();
+    Argument = parseStringTo(AsmToken::EndOfStatement);
     if (getTok().is(AsmToken::EndOfStatement))
       Argument += getTok().getString();
     size_t End = 0;
     for (; End < Argument.size(); ++End) {
       if (isSpace(Argument[End]))
         break;
     }
     Argument.resize(End);
if (!isPowerOf2_64(IntValue))
     return Error(ExprLoc, "literal value not a power of two greater then zero");
 
   Info.AsmRewrites->emplace_back(AOK_Align, IDLoc, 5, Log2_64(IntValue));
   return false;
 }
 
 bool MasmParser::parseDirectiveRadix(SMLoc DirectiveLoc) {
   const SMLoc Loc = getLexer().getLoc();
-  StringRef RadixString = parseStringToEndOfStatement().trim();
+  std::string RadixStringRaw = parseStringTo(AsmToken::EndOfStatement);
+  StringRef RadixString = StringRef(RadixStringRaw).trim();
   unsigned Radix;
   if (RadixString.getAsInteger(10, Radix)) {
     return Error(Loc,
                  "radix must be a decimal number in the range 2 to 16; was " +
                      RadixString);
   }
   if (Radix < 2 || Radix > 16)
     return Error(Loc, "radix must be in the range 2 to 16; was " +
                           std::to_string(Radix));
   getLexer().setMasmDefaultRadix(Radix);
   return false;
 }
 
+/// parseDirectiveEcho
+///   ::= "echo" message
 bool MasmParser::parseDirectiveEcho() {
-  StringRef Message = parseStringToEndOfStatement();
-  Lex();  // eat end of statement
-  llvm::outs() << Message << '\n';
+  // We're called before the directive is parsed, to avoid triggering lexical
+  // substitutions in the message. Assert that the next token is the directive,
+  // then eat it without using the Parser's Lex method.
+  assert(getTok().is(AsmToken::Identifier) &&
+         getTok().getString().equals_lower("echo"));
+  Lexer.Lex();
+
+  std::string Message = parseStringTo(AsmToken::EndOfStatement);
+  llvm::outs() << Message;
+  if (!StringRef(Message).endswith("\n"))
+    llvm::outs() << '\n';
   return false;
 }
 
 // We are comparing pointers, but the pointers are relative to a single string.
 // Thus, this should always be deterministic.
 static int rewritesSort(const AsmRewrite *AsmRewriteA,
                         const AsmRewrite *AsmRewriteB) {
   if (AsmRewriteA->Loc.getPointer() < AsmRewriteB->Loc.getPointer())

llvm/test/tools/llvm-ml/expansion.test

+; RUN: llvm-ml -filetype=asm %s 2>&1 | FileCheck %s
+
+.code
+
+num EQU 276
+var TEXTEQU %num
+
+ECHO t1
+ECHO var
+ ECHO var
+
+; CHECK-LABEL: t1
+; CHECK: var
+; CHECK: var
+; CHECK-NOT: var
+
+ECHO t2
+%ECHO var
+% ECHO var
+ %ECHO var
+ % ECHO var
+
+; CHECK-LABEL: t2
+; CHECK: 276
+; CHECK: 276
+; CHECK: 276
+; CHECK: 276
+; CHECK-NOT: 276
+
+t3:
+mov eax, var
+% mov eax, var
+
+; CHECK-LABEL: t3:
+; CHECK: mov eax, 276
+; CHECK: mov eax, 276
+
+end