X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?p=rmac;a=blobdiff_plain;f=sect.c;h=ae4d750b98b84c8ed1726b4084ba39d8e6d85551;hp=c7580631faa89cf9534f206bdfd34847cab5b13f;hb=HEAD;hpb=7d0d2b9ecddea35722fd1d09c99735b98f6f0362

diff --git a/sect.c b/sect.c
index c758063..12f9c89 100644
--- 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, 2011-2019 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
 //
@@ -18,7 +18,8 @@
 #include "riscasm.h"
 #include "symbol.h"
 #include "token.h"
-
+#define DEF_REGRISC
+#include "riscregs.h"
 
 // Function prototypes
 void MakeSection(int, uint16_t);
@@ -294,7 +295,7 @@ 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 +310,53 @@ 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
@@ -415,6 +461,21 @@ int ResolveFixups(int sno)
 			// evexpr presumably issues the errors/warnings here
 			if (evexpr(fup->expr, &eval, &eattr, &esym) != OK)
 				continue;
+
+			if (esym)
+				if (!(esym->sattr & DEFINED) && eval==0)
+				{
+					// If our expression still has an undefined symbol at this stage, it's bad news.
+					// The linker is never going to resolve the expression, so that's an error.
+					error("cannot export complex expression with unresloved symbol '%s'", esym->sname);
+					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
@@ -422,6 +483,12 @@ int ResolveFixups(int sno)
 			SYM * sy = fup->symbol;
 			eattr = sy->sattr;
 
+			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;
 			else
@@ -450,9 +517,6 @@ int ResolveFixups(int sno)
 		// from the location (that will happen in the linker when the external
 		// reference is resolved).
 		//
-		// MWC expects PC-relative things to have the LOC subtracted from the
-		// value, if the value is external (that is, undefined at this point).
-		//
 		// PC-relative fixups must be DEFINED and either in the same section
 		// (whereupon the subtraction takes place) or ABS (with no subtract).
 		if ((dw & FU_PCREL) || (dw & FU_PCRELX))
@@ -470,7 +534,7 @@ int ResolveFixups(int sno)
 				else if (tdb)
 				{
 					// Allow cross-section PCREL fixups in Alcyon mode
-					if (prg_flag)
+					if (prg_flag || (obj_format == RAW))
 					{
 						switch (tdb)
 						{
@@ -493,6 +557,9 @@ int ResolveFixups(int sno)
 						// In this instruction the PC is located a DWORD away
 						if (dw & FU_PCRELX)
 							eval += 2;
+						
+						if ((int64_t)eval > 0x7fff || (int64_t)eval < -32768)
+							error(range_error);
 					}
 					else
 					{
@@ -501,17 +568,9 @@ int ResolveFixups(int sno)
 					}
 				}
 
-				if (sbra_flag && (dw & FU_LBRA) && (eval + 0x80 < 0x100))
+				if (optim_warn_flag && (dw & FU_LBRA) && (eval + 0x80 < 0x100))
 					warn("unoptimized short branch");
 			}
-			else if (obj_format == MWC)
-			{
-				eval -= loc;
-
-				// In this instruction the PC is located a DWORD away
-				if (dw & FU_PCRELX)
-					eval += 2;
-			}
 
 			// Be sure to clear any TDB flags, since we handled it just now
 			tdb = 0;
@@ -536,11 +595,15 @@ int ResolveFixups(int sno)
 
 			if (eval == 0)
 			{
-				if (CHECK_OPTS(OPT_NULL_BRA))
+				if (*locp) // optim_flags[OPT_NULL_BRA] is stored there, check the comment in mach.s under m_br
 				{
 					// Just output a NOP
 					*locp++ = 0x4E;
 					*locp = 0x71;
+
+					if (optim_warn_flag)
+						warn("o6: bra.s with zero offset converted to NOP");
+
 					continue;
 				}
 				else
@@ -670,6 +733,7 @@ int ResolveFixups(int sno)
 			}
 			else if ((dw & FUMASKRISC) == FU_REGONE)
 			{
+				eval -= REGRISC_R0;
 				if (eval > 31)
 				{
 					error("register one value out of range");
@@ -683,6 +747,7 @@ int ResolveFixups(int sno)
 			}
 			else if ((dw & FUMASKRISC) == FU_REGTWO)
 			{
+				eval -= REGRISC_R0;
 				if (eval > 31)
 				{
 					error("register two value out of range");
@@ -895,8 +960,8 @@ 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)
 				{
@@ -907,8 +972,8 @@ 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)
 				{