Added the ParseInstruction() hook for target specific assembler directives so

that things like .word can be parsed as target specific.  Moved parsing .word
out of AsmParser.cpp into X86AsmParser.cpp as it is 2 bytes on X86 and 4 bytes
for other targets that support the .word directive.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81461 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Target/TargetAsmParser.h

@@ -10,6 +10,8 @@
 #ifndef LLVM_TARGET_TARGETPARSER_H
 #define LLVM_TARGET_TARGETPARSER_H
 
+#include "llvm/MC/MCAsmLexer.h"
+
 namespace llvm {
 class MCAsmParser;
 class MCInst;
@@ -44,6 +46,18 @@ public:
   /// \param Inst [out] - On success, the parsed instruction.
   /// \return True on failure.
   virtual bool ParseInstruction(const StringRef &Name, MCInst &Inst) = 0;
+
+  /// ParseDirective - Parse a target specific assembler directive
+  ///
+  /// The parser is positioned following the directive name.  The target
+  /// specific directive parser should parse the entire directive doing or
+  /// recording any target specific work, or return true and do nothing if the
+  /// directive is not target specific. If the directive is specific for
+  /// the target, the entire line is parsed up to and including the
+  /// end-of-statement token and false is returned.
+  ///
+  /// \param ID - the identifier token of the directive.
+  virtual bool ParseDirective(AsmToken DirectiveID) = 0;
 };
 
 } // End llvm namespace

lib/Target/X86/AsmParser/X86AsmParser.cpp

@@ -12,6 +12,7 @@
 #include "llvm/ADT/Twine.h"
 #include "llvm/MC/MCAsmLexer.h"
 #include "llvm/MC/MCAsmParser.h"
+#include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/Support/SourceMgr.h"
@@ -39,7 +40,9 @@ private:
   bool ParseOperand(X86Operand &Op);
 
   bool ParseMemOperand(X86Operand &Op);
-  
+
+  bool ParseDirectiveWord(unsigned Size, SMLoc L);
+
   /// @name Auto-generated Match Functions
   /// {  
 
@@ -57,6 +60,8 @@ public:
     : TargetAsmParser(T), Parser(_Parser) {}
 
   virtual bool ParseInstruction(const StringRef &Name, MCInst &Inst);
+
+  virtual bool ParseDirective(AsmToken DirectiveID);
 };
   
 } // end anonymous namespace
@@ -432,6 +437,38 @@ bool X86ATTAsmParser::ParseInstruction(const StringRef &Name, MCInst &Inst) {
   return true;
 }
 
+bool X86ATTAsmParser::ParseDirective(AsmToken DirectiveID) {
+  StringRef IDVal = DirectiveID.getIdentifier();
+  if (IDVal == ".word")
+    return ParseDirectiveWord(2, DirectiveID.getLoc());
+  return true;
+}
+
+/// ParseDirectiveWord
+///  ::= .word [ expression (, expression)* ]
+bool X86ATTAsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
+  if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    for (;;) {
+      const MCExpr *Value;
+      if (getParser().ParseExpression(Value))
+        return true;
+
+      getParser().getStreamer().EmitValue(Value, Size);
+
+      if (getLexer().is(AsmToken::EndOfStatement))
+        break;
+      
+      // FIXME: Improve diagnostic.
+      if (getLexer().isNot(AsmToken::Comma))
+        return Error(L, "unexpected token in directive");
+      getLexer().Lex();
+    }
+  }
+
+  getLexer().Lex();
+  return false;
+}
+
 // Force static initialization.
 extern "C" void LLVMInitializeX86AsmParser() {
   RegisterAsmParser<X86ATTAsmParser> X(TheX86_32Target);

tools/llvm-mc/AsmParser.cpp

@@ -591,10 +591,9 @@ bool AsmParser::ParseStatement() {
     if (IDVal == ".asciz")
       return ParseDirectiveAscii(true);
 
-    // FIXME: Target hooks for size? Also for "word", "hword".
     if (IDVal == ".byte")
       return ParseDirectiveValue(1);
-    if (IDVal == ".short" || IDVal == ".word")
+    if (IDVal == ".short")
       return ParseDirectiveValue(2);
     if (IDVal == ".long")
       return ParseDirectiveValue(4);
@@ -685,6 +684,10 @@ bool AsmParser::ParseStatement() {
     if (IDVal == ".loc")
       return ParseDirectiveLoc(IDLoc);
 
+    // Target hook for parsing target specific directives.
+    if (!getTargetParser().ParseDirective(ID))
+      return false;
+
     Warning(IDLoc, "ignoring directive for now");
     EatToEndOfStatement();
     return false;

tools/llvm-mc/llvm-mc.cpp

@@ -16,6 +16,7 @@
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCAsmLexer.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/Support/CommandLine.h"