Tentative fix for bug #55. Thanks to ggn for reporting!

[rmac] / parmode.h

diff --git a/parmode.h b/parmode.h
index 11b16bfbe81894d962029d18cf88d40a65930f77..38f6f94b6c787f5143c40bb98cdc0e7f806c8a0f 100644 (file)
--- a/parmode.h
+++ b/parmode.h
@@ -3,7 +3,7 @@
 // PARMODE.C - Addressing Modes Parser Include
 // Copyright (C) 199x Landon Dyer, 2011 Reboot and Friends
 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
-// Source Utilised with the Kind Permission of Landon Dyer
+// Source utilised with the kind permission of Landon Dyer
 //
 
 // This file is included (twice) to parse two addressing modes, into slightly
@@ -31,6 +31,11 @@
 
                AMn = IMMED;
        }
+
+       // Small problem with this is that the opening parentheses might be an
+       // expression that's part of a displacement; this code will falsely flag
+       // that as an error.
+
        // (An)
        // (An)+
        // (An,Xn[.siz][*scale])
@@ -145,6 +150,15 @@
                        if (expr(AnEXPR, &AnEXVAL, &AnEXATTR, &AnESYM) != OK)
                                return ERROR;
 
+                       // It could be that this is really just an expression prefixing a
+                       // register as a displacement...
+                       if (*tok == ')')
+                       {
+                               tok++;
+                               goto CHK_FOR_DISPn;
+                       }
+
+                       // Otherwise, check for PC & etc displacements...
                        if (*tok++ != ',')
                                goto badmode;
 
@@ -223,22 +237,27 @@
                if (expr(AnEXPR, &AnEXVAL, &AnEXATTR, &AnESYM) != OK)
                        return ERROR;
 
+CHK_FOR_DISPn:
                if (*tok == DOTW)
-               {                                    // expr.W 
+               {
+                       // expr.W 
                        tok++;
                        AMn = ABSW;
                        goto AnOK;
                }
                else if (*tok != '(')
-               {                              // expr[.L]
+               {
+                       // expr[.L]
                        AMn = ABSL;
-                       // Defined, absolute values from $FFFF8000..$00007FFF get optimized to absolute short
 
+                       // Defined, absolute values from $FFFF8000..$00007FFF get optimized
+                       // to absolute short
                        if ((AnEXATTR & (TDB|DEFINED)) == DEFINED && (AnEXVAL + 0x8000) < 0x10000)
                                AMn = ABSW;
 
+                       // Is .L forced here?
                        if (*tok == DOTL)
-                       {                                 // force .L 
+                       {
                                tok++;
                                AMn = ABSL;
                        }
@@ -246,7 +265,7 @@
                        goto AnOK;
                }
 
-               ++tok;
+               tok++;
 
                if ((*tok >= KW_A0) && (*tok <= KW_A7))
                {
@@ -283,7 +302,7 @@
        ;
 }
 
-// Cleanup dirty little macros
+// Clean up dirty little macros
 #undef AnOK
 #undef AMn
 #undef AnREG
@@ -298,3 +317,4 @@
 #undef AnESYM
 #undef AMn_IX0
 #undef AMn_IXN
+#undef CHK_FOR_DISPn