Added symbol definitions on the command line and weak symbols in the config.

git-svn-id: svn://svn.cc65.org/cc65/trunk@3552 b7a2c559-68d2-44c3-8de9-860c34a00d81

src/ld65/config.c

@@ -1335,7 +1335,7 @@ static void ParseFeatures (void)
 
 
     	    default:
-    	 	Error ("Unexpected feature token");
+       	       	FAIL ("Unexpected feature token");
     	}
 
     	/* Skip the semicolon */
@@ -1359,7 +1359,7 @@ static void ParseSymbols (void)
     while (CfgTok == CFGTOK_IDENT) {
 
 	long Val = 0L;
-        int  Weak;
+        int  Weak = 0;
 
 	/* Remember the name */
 	unsigned Name = GetStringId (CfgSVal);
@@ -1381,9 +1381,6 @@ static void ParseSymbols (void)
             Val = CfgIVal;
             CfgNextTok ();
 
-            /* Generate an export with the given value */
-            CreateConstExport (Name, Val);
-
         } else {
 
             /* Bitmask to remember the attributes we got already */
@@ -1453,7 +1450,18 @@ static void ParseSymbols (void)
                 Weak = 0;
             }
 
-            /* Generate an export with the given value */
+        }
+
+        /* Check if the symbol is already defined */
+        if (FindExport (Name) != 0) {
+            /* If the symbol is not marked as weak, this is an error.
+             * Otherwise ignore the symbol from the config.
+             */
+            if (!Weak) {
+                CfgError ("Symbol `%s' is already defined", GetString (Name));
+            }
+        } else {
+            /* The symbol is undefined, generate an export */
             CreateConstExport (Name, Val);
         }