DEBUG = TRUE
INCLUDE "Main.6502"

DEBUG = FALSE
INCLUDE "Main.6502"

all: source
        beebasm -DDEBUG -oDEBUG.ROM source
        beebasm -oPROD.ROM source

Only in beebasm-new: beebasm
diff -cr beebasm-c35bc523430d/src/commands.cpp beebasm-new/src/commands.cpp
*** beebasm-c35bc523430d/src/commands.cpp   Mon Apr  8 21:04:15 2013
--- beebasm-new/src/commands.cpp   Mon Apr  8 21:09:06 2013
***************
*** 56,61 ****
--- 56,63 ----
     { "SAVE",      &LineParser::HandleSave,         0 },
     { "FOR",      &LineParser::HandleFor,            0 },
     { "NEXT",      &LineParser::HandleNext,         0 },
+    { "IFDEF",      &LineParser::HandleIfDef,         &SourceFile::AddIfLevel },
+    { "ELIFDEF",      &LineParser::HandleIfDef,         &SourceFile::StartElif },
     { "IF",         &LineParser::HandleIf,            &SourceFile::AddIfLevel },
     { "ELIF",      &LineParser::HandleIf,            &SourceFile::StartElif },
     { "ELSE",      &LineParser::HandleDirective,         &SourceFile::StartElse },
***************
*** 1296,1301 ****
--- 1298,1317 ----
     }
  }
 
+ void LineParser::HandleIfDef()
+ {
+    if (!LineParser::MoveToNextAtom())
+    {
+       throw AsmException_SyntaxError_EmptyExpression( m_line, m_column );
+    }
+    else
+    {
+       string symbolName = GetSymbolName();
+       bool condition = SymbolTable::Instance().IsSymbolDefined(symbolName);
+       m_sourceCode->SetCurrentIfCondition( condition );
+    }
+ }   
+
 
 
  /*************************************************************************************************/
diff -cr beebasm-c35bc523430d/src/lineparser.h beebasm-new/src/lineparser.h
*** beebasm-c35bc523430d/src/lineparser.h   Mon Apr  8 21:04:15 2013
--- beebasm-new/src/lineparser.h   Mon Apr  8 21:05:53 2013
***************
*** 143,148 ****
--- 143,149 ----
     void         HandleOpenBrace();
     void         HandleCloseBrace();
     void         HandleIf();
+    void         HandleIfDef();
     void         HandleAlign();
     void         HandleSkip();
     void         HandleSkipTo();
diff -cr beebasm-c35bc523430d/src/main.cpp beebasm-new/src/main.cpp
*** beebasm-c35bc523430d/src/main.cpp   Mon Apr  8 21:04:15 2013
--- beebasm-new/src/main.cpp   Mon Apr  8 21:15:56 2013
***************
*** 67,72 ****
--- 67,73 ----
        READY,
        WAITING_FOR_INPUT_FILENAME,
        WAITING_FOR_OUTPUT_FILENAME,
+       WAITING_FOR_DEFINE_NAME,
        WAITING_FOR_DISC_INPUT_FILENAME,
        WAITING_FOR_DISC_OUTPUT_FILENAME,
        WAITING_FOR_BOOT_FILENAME,
***************
*** 77,82 ****
--- 78,84 ----
     bool bDumpSymbols = false;
 
     GlobalData::Create();
+    SymbolTable::Create();
 
     // Parse command line parameters
 
***************
*** 94,99 ****
--- 96,105 ----
              {
                 state = WAITING_FOR_OUTPUT_FILENAME;
              }
+             else if ( strcmp( argv[i], "-D" ) == 0 )
+             {
+                state = WAITING_FOR_DEFINE_NAME;
+             }
              else if ( strcmp( argv[i], "-do" ) == 0 )
              {
                 state = WAITING_FOR_DISC_OUTPUT_FILENAME;
***************
*** 124,129 ****
--- 130,136 ----
                 cout << "Possible options:" << endl;
                 cout << " -i <file>      Specify source filename" << endl;
                 cout << " -o <file>      Specify output filename (when not specified by SAVE command)" << endl;
+                cout << " -D NAME        Sets NAME = TRUE as a global variable" << endl;
                 cout << " -di <file>     Specify a disc image file to be added to" << endl;
                 cout << " -do <file>     Specify a disc image file to output" << endl;
                 cout << " -boot <file>   Specify a filename to be run by !BOOT on a new disc image" << endl;
***************
*** 156,161 ****
--- 163,173 ----
              state = READY;
              break;
 
+          case WAITING_FOR_DEFINE_NAME:
+             SymbolTable::Instance().AddSymbol (argv[i],-1);
+             state = READY;
+             break;
+
 
           case WAITING_FOR_DISC_OUTPUT_FILENAME:
 
***************
*** 213,219 ****
 
     int exitCode = EXIT_SUCCESS;
 
-    SymbolTable::Create();
     ObjectCode::Create();
     MacroTable::Create();
     SetupBASICTables();
--- 225,230 ----
Only in beebasm-new/src: objects

void LineParser::HandleIfDef()
{
    // check there's something following the IFDEF
    if (!AdvanceAndCheckEndOfStatement())
    {
        throw AsmException_SyntaxError_EmptyExpression(m_line, m_column);
    }
    else
    {
        // check it's a valid symbol name
        if (!isalpha(m_line[m_column]) && m_line[m_column] != '_')
        {
            throw AsmException_SyntaxError_InvalidSymbolName(m_line, m_column);
        }

        string symbolName = GetSymbolName();
        bool bSymbolDefined = (SymbolTable::Instance().IsSymbolDefined(symbolName);
        m_sourceCode->SetCurrentIfCondition(bSymbolDefined);

        // now insist that there's nothing following the symbol name other than a valid statement separator
        if (AdvanceAndCheckEndOfStatement())
        {
            throw AsmException_SyntaxError_InvalidCharacter(m_line, m_column);
        }
    }
}

globalsymbol = TRUE
{
    localsymbol = TRUE
    IFDEF globalsymbol
        PRINT"You will see this..."
    ENDIF
    IFDEF localsymbol
        PRINT"...but you will never see this"
    ENDIF
}

/tmp/a:10: error: Invalid symbol name; must start with a letter and contain only letters, numbers and underscore.

IFDEF 645
      ^

../beebasm -i /tmp/a -o /tmp/b -v
/tmp/a:16: error: Bad expression.

IFDEF _fli4 hello there
            ^

../beebasm -i /tmp/a -o /tmp/b -v
/tmp/a:22: error: Expression not found.

IFDEF
     ^

IFDEF FOO
   EQUB 1
ELSE
  FOO=TRUE
  EQUB 2
ENDIF