[AsmParser] Support GAS's .print directive

[javed.absar]

lib/MC/MCParser/AsmParser.cpp

542

Putting DK_PRINT beyond DK_END doesn't seem right

[coby]

lib/MC/MCParser/AsmParser.cpp

542

ah.. DK_END stands for the ".end" directive and holds no other semantical purposes.. but I can see your point :)
will be relocated.
anything else other than this?

[javed.absar]

lib/MC/MCParser/AsmParser.cpp

542

OK from my side. Thanks.

[mcrosier]

LGTM.

[mcrosier]

In D38448#885704, @mcrosier wrote:

LGTM.

(Assuming the enum ordering is addressed, of course.)

[coby]

thanks for the prompt review.
will address enum's values definition ordering upon the commit itself

lib/MC/MCParser/AsmParser.cpp

enum DirectiveKind {
     DK_ENDM,
     DK_ENDMACRO,
     DK_PURGEM,
     DK_SLEB128,
     DK_ULEB128,
     DK_ERR,
     DK_ERROR,
     DK_WARNING,
-    DK_END
+    DK_END,
+    DK_PRINT
   };
 
   /// \brief Maps directive name --> DirectiveKind enum, for
   /// directives parsed by this class.
   StringMap<DirectiveKind> DirectiveKindMap;
 
   // ".ascii", ".asciz", ".string"
   bool parseDirectiveAscii(StringRef IDVal, bool ZeroTerminated);
private:
   bool parseDirectiveEnd(SMLoc DirectiveLoc);
 
   // ".err" or ".error"
   bool parseDirectiveError(SMLoc DirectiveLoc, bool WithMessage);
 
   // ".warning"
   bool parseDirectiveWarning(SMLoc DirectiveLoc);
 
+  // .print <double-quotes-string>
+  bool parseDirectivePrint(SMLoc DirectiveLoc);
+
   void initializeDirectiveKindMap();
 };
 
 } // end anonymous namespace
 
 namespace llvm {
 
 extern MCAsmParserExtension *createDarwinAsmParser();
if (IDVal[0] == '.' && IDVal != ".") {
     case DK_DS_D:
       return parseDirectiveDS(IDVal, 8);
     case DK_DS_L:
     case DK_DS_S:
       return parseDirectiveDS(IDVal, 4);
     case DK_DS_P:
     case DK_DS_X:
       return parseDirectiveDS(IDVal, 12);
+    case DK_PRINT:
+      return parseDirectivePrint(IDLoc);
     }
 
     return Error(IDLoc, "unknown directive");
   }
 
   // __asm _emit or __asm __emit
   if (ParsingInlineAsm && (IDVal == "_emit" || IDVal == "__emit" ||
                            IDVal == "_EMIT" || IDVal == "__EMIT"))
void AsmParser::initializeDirectiveKindMap() {
   DirectiveKindMap[".ds"] = DK_DS;
   DirectiveKindMap[".ds.b"] = DK_DS_B;
   DirectiveKindMap[".ds.d"] = DK_DS_D;
   DirectiveKindMap[".ds.l"] = DK_DS_L;
   DirectiveKindMap[".ds.p"] = DK_DS_P;
   DirectiveKindMap[".ds.s"] = DK_DS_S;
   DirectiveKindMap[".ds.w"] = DK_DS_W;
   DirectiveKindMap[".ds.x"] = DK_DS_X;
+  DirectiveKindMap[".print"] = DK_PRINT;
 }
 
 MCAsmMacro *AsmParser::parseMacroLikeBody(SMLoc DirectiveLoc) {
   AsmToken EndToken, StartToken = getTok();
 
   unsigned NestLevel = 0;
   while (true) {
     // Check whether we have reached the end of the file.
bool AsmParser::parseDirectiveMSAlign(SMLoc IDLoc, ParseStatementInfo &Info) {
   uint64_t IntValue = MCE->getValue();
   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 AsmParser::parseDirectivePrint(SMLoc DirectiveLoc) {
+  const AsmToken StrTok = getTok();
+  Lex();
+  if (StrTok.isNot(AsmToken::String) || StrTok.getString().front() != '"')
+    return Error(DirectiveLoc, "expected double quoted string after .print");
+  if (parseToken(AsmToken::EndOfStatement, "expected end of statement"))
+    return true;
+  llvm::outs() << StrTok.getStringContents() << '\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())
     return -1;
   if (AsmRewriteB->Loc.getPointer() < AsmRewriteA->Loc.getPointer())
     return 1;

test/MC/AsmParser/directive_print.s

+# RUN: not llvm-mc -triple i386-linux-gnu %s 2> %t.err | FileCheck %s
+# RUN: FileCheck < %t.err %s --check-prefix=CHECK-ERR
+
+T1:
+# CHECK: e
+# CHECK: 2.718281828459045235
+.print "e"
+.print "2.718281828459045235"
+
+T2:
+# CHECK-ERR: expected double quoted string after .print
+.print 'pi'
+
+T3:
+# CHECK-ERR: expected end of statement
+.print "a" "misplaced-string"