Fix for bug #78: Thanks to ggn for reporting and supplying the patch.

[rmac] / parmode.h

diff --git a/parmode.h b/parmode.h
index 4637d72dda1bca9613a2484de82f4bf68ffb9f4c..521f787e9fe39897b4bfe5d7797fc79b3aabd7cd 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
@@ -24,12 +24,18 @@
        }
        else if (*tok == '#')
        {
-               ++tok;
+               tok++;
+
                if (expr(AnEXPR, &AnEXVAL, &AnEXATTR, &AnESYM) != OK)
                        return ERROR;
 
                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])
@@ -44,7 +50,7 @@
        // ([bd,PC,Xn],od)
        else if (*tok == '(')
        {
-               ++tok;
+               tok++;
 
                if ((*tok >= KW_A0) && (*tok <= KW_A7))
                {
@@ -52,11 +58,11 @@
 
                        if (*tok == ')')
                        {
-                               ++tok;
+                               tok++;
 
                                if (*tok == '+')
                                {
-                                       ++tok;
+                                       tok++;
                                        AMn = APOSTINC;
                                }
                                else
@@ -66,21 +72,22 @@
                        }
 
                        AMn = AINDEXED;
-                       goto AMn_IX0;                                      // Handle ",Xn[.siz][*scale])"
+                       goto AMn_IX0;            // Handle ",Xn[.siz][*scale])"
                }
                else if (*tok == KW_PC)
                {                            // (PC,Xn[.siz][*scale]) 
-                       ++tok;
+                       tok++;
                        AMn = PCINDEXED;
 
-                       // Common index handler; enter here with `tok' pointing at the comma.
+                       // Common index handler; enter here with 'tok' pointing at the
+                       // comma.
 
-                       AMn_IX0:                                           // Handle indexed with missing expr
+                       AMn_IX0:                 // Handle indexed with missing expr
 
                        AnEXVAL = 0;
                        AnEXATTR = ABS | DEFINED;
 
-                       AMn_IXN:                                           // Handle any indexed (tok -> a comma)
+                       AMn_IXN:                 // Handle any indexed (tok -> a comma)
 
                        if (*tok++ != ',')
                                goto badmode;
@@ -91,23 +98,24 @@
                        AnIXREG = *tok++ & 15;
 
                        switch ((int)*tok)
-                       {                                // Index reg size: <empty> | .W | .L 
+                       {                        // Index reg size: <empty> | .W | .L 
                        case DOTW:
-                               ++tok;
+                               tok++;
                        default:
                                AnIXSIZ = 0;
                                break;
                        case DOTL:
                                AnIXSIZ = 0x0800;
-                               ++tok;
+                               tok++;
                                break;
-                       case DOTB:                                      // .B not allowed here...
+                       case DOTB:               // .B not allowed here...
                                goto badmode;
                        }
 
                        if (*tok == '*')
-                       {                                  // scale: *1, *2, *4, *8 
-                               ++tok;
+                       {                        // scale: *1, *2, *4, *8 
+                               tok++;
+
                                if (*tok++ != CONST || *tok > 8)
                                        goto badmode;
 
@@ -129,7 +137,7 @@
                                }
                        }
 
-                       if (*tok++ != ')')                                  // final ")" 
+                       if (*tok++ != ')')         // final ")" 
                                goto badmode;
 
                        goto AnOK;
@@ -139,17 +147,26 @@
                        goto unmode;
                }
                else
-               {                                              // (expr... 
+               {                              // (expr... 
                        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;
 
                        if ((*tok >= KW_A0) && (*tok <= KW_A7))
                        {
                                AnREG = *tok & 7;
-                               ++tok;
+                               tok++;
 
                                if (*tok == ',')
                                {
@@ -159,7 +176,7 @@
                                else if (*tok == ')')
                                {
                                        AMn = ADISP;
-                                       ++tok;
+                                       tok++;
                                        goto AnOK;
                                }
                                else
@@ -174,8 +191,8 @@
                                }
                                else if (*tok == ')')
                                {
-                                       AMn = PCDISP;                                // expr(PC) 
-                                       ++tok;
+                                       AMn = PCDISP;             // expr(PC) 
+                                       tok++;
                                        goto AnOK;
                                }
                                else
@@ -185,7 +202,7 @@
                                goto badmode;
                }
        }
-       else if (*tok=='-' && tok[1]=='(' && ((tok[2]>=KW_A0) && (tok[2]<=KW_A7)) && tok[3]==')')
+       else if (*tok == '-' && tok[1] == '(' && ((tok[2] >= KW_A0) && (tok[2] <= KW_A7)) && tok[3] == ')')
        {
                AMn = APREDEC;
                AnREG = tok[2] & 7;
@@ -194,19 +211,19 @@
        else if (*tok == KW_CCR)
        {
                AMn = AM_CCR;
-               ++tok;
+               tok++;
                goto AnOK;
        }
        else if (*tok == KW_SR)
        {
                AMn = AM_SR;
-               ++tok;
+               tok++;
                goto AnOK;
        }
        else if (*tok == KW_USP)
        {
                AMn = AM_USP;
-               ++tok;
+               tok++;
                goto AnOK;
        }
        // expr
@@ -221,30 +238,44 @@
                if (expr(AnEXPR, &AnEXVAL, &AnEXATTR, &AnESYM) != OK)
                        return ERROR;
 
+CHK_FOR_DISPn:
                if (*tok == DOTW)
-               {                                    // expr.W 
-                       ++tok;
+               {
+                       // expr.W 
+                       tok++;
                        AMn = ABSW;
+
+                       if ((AnEXATTR & (TDB|DEFINED)) == DEFINED && (AnEXVAL < 0x10000))
+                               AnEXVAL = (int32_t)(int16_t)AnEXVAL;  // Sign extend value
+
                        goto AnOK;
                }
                else if (*tok != '(')
-               {                              // expr[.L]
+               {
+                       // expr[.L]
                        AMn = ABSL;
-                       // Defined, absolute values from $FFFF8000..$00007FFF get optimized to absolute short
 
-                       if ((AnEXATTR & (TDB|DEFINED)) == DEFINED && (AnEXVAL + 0x8000) < 0x10000)
+                       // Defined, absolute values from $FFFF8000..$00007FFF get optimized
+                       // to absolute short
+                       if (optim_flag && (AnEXATTR & (TDB|DEFINED)) == DEFINED && (AnEXVAL + 0x8000) < 0x10000)
+                       {
                                AMn = ABSW;
 
+                               if (sbra_flag)
+                                       warn("absolute value from $FFFF8000..$00007FFF optimised to absolute short");
+                       }
+
+                       // Is .L forced here?
                        if (*tok == DOTL)
-                       {                                 // force .L 
-                               ++tok;
+                       {
+                               tok++;
                                AMn = ABSL;
                        }
 
                        goto AnOK;
                }
 
-               ++tok;
+               tok++;
 
                if ((*tok >= KW_A0) && (*tok <= KW_A7))
                {
@@ -253,7 +284,7 @@
                        if (*tok == ')')
                        {
                                AMn = ADISP;
-                               ++tok;
+                               tok++;
                                goto AnOK;
                        }
 
@@ -265,7 +296,7 @@
                        if (*++tok == ')')
                        {
                                AMn = PCDISP;
-                               ++tok;
+                               tok++;
                                goto AnOK;
                        }
 
@@ -281,7 +312,7 @@
        ;
 }
 
-// Cleanup dirty little macros
+// Clean up dirty little macros
 #undef AnOK
 #undef AMn
 #undef AnREG
@@ -296,3 +327,4 @@
 #undef AnESYM
 #undef AMn_IX0
 #undef AMn_IXN
+#undef CHK_FOR_DISPn