.equr overhaul part 4: handle equrundef (and the other permutations of the directive)

[rmac] / sect.c

diff --git a/sect.c b/sect.c
index cdf53ffc1ab5e650848211a030931580eb349a11..c00a9d6990bb2635928ec0b54b3ff87bcc95989d 100644 (file)
--- a/sect.c
+++ b/sect.c
@@ -1,7 +1,7 @@
 //
-// RMAC - Reboot's Macro Assembler for all Atari computers
+// RMAC - Renamed Macro Assembler for all Atari computers
 // SECT.C - Code Generation, Fixups and Section Management
-// Copyright (C) 199x Landon Dyer, 2011-2020 Reboot and Friends
+// Copyright (C) 199x Landon Dyer, 2011-2021 Reboot and Friends
 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
 // Source utilised with the kind permission of Landon Dyer
 //
@@ -294,7 +294,7 @@ int AddFixup(uint32_t attr, uint32_t loc, TOKEN * fexpr)
        }
 
        // Allocate space for the fixup + any expression
-       FIXUP * fixup = malloc(sizeof(FIXUP) + (sizeof(TOKEN) * exprlen));
+       FIXUP * fixup = malloc(sizeof(FIXUP) + (sizeof(TOKEN) * exprlen)*2);
 
        // Store the relevant fixup information in the FIXUP
        fixup->next = NULL;
@@ -309,8 +309,53 @@ int AddFixup(uint32_t attr, uint32_t loc, TOKEN * fexpr)
        // Copy the passed in expression to the FIXUP, if any
        if (exprlen > 0)
        {
+               // Here we used to to a plain memcpy and punt on trying to evaluate the expression by then.
+               // As discussed in bug #176, this can lead to robustness issues because some symbols might
+               // have changed by the time we perform the relocations (think of a symbol that's SET multiple
+               // times). So instead we perform a symbol-by-symbol copy and check to see if there are any
+               // resolved symbols that can be evaluated immediately. Those, we replace with constants.
+               // Also of note: because "fixup" can be larger than what ExpressionLength() returns
+               // (due to constants taking up more space than symbols), we allocate twice as RAM as we should
+               // without expansions just to be on the safe side. The "correct" thing to do would be to
+               // modify ExpressionLength() to cater for defined symbols and return the exact amount of items.
+
                fixup->expr = (TOKEN *)((uint8_t *)fixup + sizeof(FIXUP));
-               memcpy(fixup->expr, fexpr, sizeof(TOKEN) * exprlen);
+               int i;
+               PTR dstexpr;
+               dstexpr.u32 = fixup->expr;
+               SYM *sy;
+               for (i = 0; i < exprlen; i++)
+               {
+                       if (*fexpr == SYMBOL)
+                       {
+                               sy = symbolPtr[fexpr[1]];
+                               if (sy->sattr & DEFINED && !(sy->sattr & (TDB| M56KPXYL|M6502)))
+                               {
+                                       // Only convert symbols that are defined and are absolute
+                                       *dstexpr.u32++ = CONST;
+                                       *dstexpr.u64++ = sy->svalue;
+                                       fexpr += 2;
+                                       i++;
+                               }
+                               else
+                               {
+                                       // Just copy the symbol
+                                       *dstexpr.u32++ = *fexpr++;
+                                       *dstexpr.u32++ = *fexpr++;
+                                       i++;
+                               }
+                       }
+                       else if (*fexpr == CONST || *fexpr == FCONST)
+                       {
+                               // Copy constants
+                               *dstexpr.u32++ = *fexpr++;
+                               *dstexpr.u32++ = *fexpr++;
+                               *dstexpr.u32++ = *fexpr++;
+                               i += 2;
+                       }
+                       else
+                               *dstexpr.u32++ = *fexpr++;
+               }
        }
 
        // Finally, put the FIXUP in the current section's linked list
@@ -416,14 +461,11 @@ int ResolveFixups(int sno)
                        if (evexpr(fup->expr, &eval, &eattr, &esym) != OK)
                                continue;
 
-                       if (CHECK_OPTS(OPT_PC_RELATIVE))
-                               if (eattr & REFERENCED)
-                                       if (eattr & DEFINED)
-                                               if (!(eattr & EQUATED))
-                                               {
-                                                       error("relocation not allowed");
-                                                       continue;
-                                               }
+                       if ((CHECK_OPTS(OPT_PC_RELATIVE)) && (eattr & (DEFINED | REFERENCED | EQUATED)) == (DEFINED | REFERENCED))
+                       {
+                               error("relocation not allowed when o30 is enabled");
+                               continue;
+                       }
                }
                // Simple symbol
                else
@@ -431,14 +473,11 @@ int ResolveFixups(int sno)
                        SYM * sy = fup->symbol;
                        eattr = sy->sattr;
 
-                       if (CHECK_OPTS(OPT_PC_RELATIVE))
-                               if (eattr & REFERENCED)
-                                       if (eattr & DEFINED)
-                                               if (!(eattr & EQUATED))
-                                               {
-                                                       error("relocation not allowed");
-                                                       continue;
-                                               }
+                       if ((CHECK_OPTS(OPT_PC_RELATIVE)) && (eattr & (DEFINED | REFERENCED | EQUATED)) == (DEFINED | REFERENCED))
+                       {
+                               error("relocation not allowed when o30 is enabled");
+                               continue;
+                       }
 
                        if (eattr & DEFINED)
                                eval = sy->svalue;
@@ -548,8 +587,10 @@ int ResolveFixups(int sno)
                                        // Just output a NOP
                                        *locp++ = 0x4E;
                                        *locp = 0x71;
+
                                        if (optim_warn_flag)
-                                               warn("bra.s with zero offset converted to NOP");
+                                               warn("o6: bra.s with zero offset converted to NOP");
+
                                        continue;
                                }
                                else
@@ -904,8 +945,8 @@ int ResolveFixups(int sno)
                                locp[1] = (uint8_t)eval;
                                break;
 
-                       // This is a 6 bit absoulte short address. It occupies
-                       // the low 6 bits of the middle byte of a DSP word.
+                       // This is a 6 bit absoulte short address. It occupies the low 6
+                       // bits of the middle byte of a DSP word.
                        case FU_DSPADR06:
                                if (eval > 63)
                                {
@@ -916,8 +957,8 @@ int ResolveFixups(int sno)
                                locp[1] |= eval;
                                break;
 
-                       // This is a 6 bit absoulte short address. It occupies
-                       // the low 6 bits of the middle byte of a DSP word.
+                       // This is a 6 bit absoulte short address. It occupies the low 6
+                       // bits of the middle byte of a DSP word.
                        case FU_DSPPP06:
                                if (eval < 0xFFFFFFC0)
                                {