set up the top-level parsing loop.

llvm-svn: 73860

1 files changed, 54 insertions, 0 deletions

diff --git a/llvm/tools/llvm-mc/AsmParser.cpp b/llvm/tools/llvm-mc/AsmParser.cpp
index abb0d35b086..9c0b4abb076 100644
--- a/llvm/tools/llvm-mc/AsmParser.cpp
+++ b/llvm/tools/llvm-mc/AsmParser.cpp
@@ -12,8 +12,62 @@
 //===----------------------------------------------------------------------===//
 
 #include "AsmParser.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
 bool AsmParser::Run() {
+  // Prime the lexer.
+  Lexer.Lex();
+  
+  while (Lexer.isNot(asmtok::Eof))
+    if (ParseStatement())
+      return true;
+  
+  return false;
+}
+
+
+/// ParseStatement:
+///   ::= EndOfStatement
+///   ::= Label* Identifier Operands* EndOfStatement
+bool AsmParser::ParseStatement() {
+  switch (Lexer.getKind()) {
+  default:
+    Lexer.PrintError(Lexer.getLoc(), "unexpected token at start of statement");
+    return true;
+  case asmtok::EndOfStatement:
+    Lexer.Lex();
+    return false;
+  case asmtok::Identifier:
+    break;
+  // TODO: Recurse on local labels etc.
+  }
+  
+  // If we have an identifier, handle it as the key symbol.
+  //SMLoc IDLoc = Lexer.getLoc();
+  std::string IDVal = Lexer.getCurStrVal();
+  
+  // Consume the identifier, see what is after it.
+  if (Lexer.Lex() == asmtok::Colon) {
+    // identifier ':'   -> Label.
+    Lexer.Lex();
+    return ParseStatement();
+  }
+  
+  // Otherwise, we have a normal instruction or directive.  
+  if (IDVal[0] == '.')
+    outs() << "Found directive: " << IDVal << "\n";
+  else
+    outs() << "Found instruction: " << IDVal << "\n";
+
+  // Skip to end of line for now.
+  while (Lexer.isNot(asmtok::EndOfStatement) &&
+         Lexer.isNot(asmtok::Eof))
+    Lexer.Lex();
+  
+  // Eat EOL.
+  if (Lexer.is(asmtok::EndOfStatement))
+    Lexer.Lex();
   return false;
 }