From ce4bec8e0ce57f3e11fb34db49cf81ffdf216f78 Mon Sep 17 00:00:00 2001
From: Kevin Enderby <enderby@apple.com>
Date: Thu, 10 Sep 2009 20:51:44 +0000
Subject: [PATCH] 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.

llvm-svn: 81461
---
 llvm/include/llvm/Target/TargetAsmParser.h    | 14 +++++++
 .../lib/Target/X86/AsmParser/X86AsmParser.cpp | 39 ++++++++++++++++++-
 llvm/tools/llvm-mc/AsmParser.cpp              |  7 +++-
 llvm/tools/llvm-mc/llvm-mc.cpp                |  1 +
 4 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/llvm/include/llvm/Target/TargetAsmParser.h b/llvm/include/llvm/Target/TargetAsmParser.h
index 8b8b2106ee68..ef1fc49cefee 100644
--- a/llvm/include/llvm/Target/TargetAsmParser.h
+++ b/llvm/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
diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index e5f23e018bf3..aa04ba60d377 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/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);
diff --git a/llvm/tools/llvm-mc/AsmParser.cpp b/llvm/tools/llvm-mc/AsmParser.cpp
index f51f43adc122..b1e8e9ae404f 100644
--- a/llvm/tools/llvm-mc/AsmParser.cpp
+++ b/llvm/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;
diff --git a/llvm/tools/llvm-mc/llvm-mc.cpp b/llvm/tools/llvm-mc/llvm-mc.cpp
index bf3c01794bca..e5d99be9e93f 100644
--- a/llvm/tools/llvm-mc/llvm-mc.cpp
+++ b/llvm/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"