* symbols.c (resolve_symbol_value): Don't change X_add_number for

	an equated symbol.
	* write.c (write_relocs): Avoid looping on equated symbols.
	Adjust fx_offset by X_add_number for each symbol.
	* config/obj-coff.c (do_relocs_for): Avoid looping on equated
	symbols.
	(fixup_segment): Add a loop to track down equated symbols and
	adjust fx_offset appropriately.

diff --git a/gas/ChangeLog b/gas/ChangeLog
index c917491..51d9df0 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,14 @@
+Mon Feb  3 12:35:54 1997  Ian Lance Taylor  <ian@cygnus.com>
+
+       * symbols.c (resolve_symbol_value): Don't change X_add_number for
+       an equated symbol.
+       * write.c (write_relocs): Avoid looping on equated symbols.
+       Adjust fx_offset by X_add_number for each symbol.
+       * config/obj-coff.c (do_relocs_for): Avoid looping on equated
+       symbols.
+       (fixup_segment): Add a loop to track down equated symbols and
+       adjust fx_offset appropriately.
+
 Fri Jan 31 15:21:02 1997  Jeffrey A Law  (law@cygnus.com)
 
        * config/tc-mn10200.c (md_relax_table): Add entries to allow

diff --git a/gas/symbols.c b/gas/symbols.c
index fa2fadb..def3f6b 100644 (file)
--- a/gas/symbols.c
+++ b/gas/symbols.c
@@ -639,7 +639,35 @@ resolve_symbol_value (symp)
 
       symp->sy_resolving = 1;
 
-    reduce:
+      /* Simplify addition or subtraction of a constant by folding the
+         constant into X_add_number.  */
+      if (symp->sy_value.X_op == O_add
+         || symp->sy_value.X_op == O_subtract)
+       {
+         resolve_symbol_value (symp->sy_value.X_add_symbol);
+         resolve_symbol_value (symp->sy_value.X_op_symbol);
+         if (S_GET_SEGMENT (symp->sy_value.X_op_symbol) == absolute_section)
+           {
+             right = S_GET_VALUE (symp->sy_value.X_op_symbol);
+             if (symp->sy_value.X_op == O_add)
+               symp->sy_value.X_add_number += right;
+             else
+               symp->sy_value.X_add_number -= right;
+             symp->sy_value.X_op = O_symbol;
+             symp->sy_value.X_op_symbol = NULL;
+           }
+         else if ((S_GET_SEGMENT (symp->sy_value.X_add_symbol)
+                   == absolute_section)
+                  && symp->sy_value.X_op == O_add)
+           {
+             left = S_GET_VALUE (symp->sy_value.X_add_symbol);
+             symp->sy_value.X_add_symbol = symp->sy_value.X_op_symbol;
+             symp->sy_value.X_add_number += left;
+             symp->sy_value.X_op = O_symbol;
+             symp->sy_value.X_op_symbol = NULL;
+           }
+       }
+
       switch (symp->sy_value.X_op)
        {
        case O_absent:
@@ -668,22 +696,26 @@ resolve_symbol_value (symp)
          if (symp->sy_value.X_add_number == 0)
            copy_symbol_attributes (symp, symp->sy_value.X_add_symbol);
 
-         S_SET_VALUE (symp,
-                      (symp->sy_value.X_add_number
-                       + symp->sy_frag->fr_address
-                       + S_GET_VALUE (symp->sy_value.X_add_symbol)));
-         if (S_GET_SEGMENT (symp) == expr_section
-             || S_GET_SEGMENT (symp) == undefined_section)
-           S_SET_SEGMENT (symp,
-                          S_GET_SEGMENT (symp->sy_value.X_add_symbol));
-
          /* If we have equated this symbol to an undefined symbol, we
-             keep X_op set to O_symbol.  This permits the routine
-             which writes out relocation to detect this case, and
-             convert the relocation to be against the symbol to which
-             this symbol is equated.  */
-         if (! S_IS_DEFINED (symp) || S_IS_COMMON (symp))
+             keep X_op set to O_symbol, and we don't change
+             X_add_number.  This permits the routine which writes out
+             relocation to detect this case, and convert the
+             relocation to be against the symbol to which this symbol
+             is equated.  */
+         if (! S_IS_DEFINED (symp->sy_value.X_add_symbol)
+             || S_IS_COMMON (symp->sy_value.X_add_symbol))
            symp->sy_value.X_op = O_symbol;
+         else
+           {
+             S_SET_VALUE (symp,
+                          (symp->sy_value.X_add_number
+                           + symp->sy_frag->fr_address
+                           + S_GET_VALUE (symp->sy_value.X_add_symbol)));
+             if (S_GET_SEGMENT (symp) == expr_section
+                 || S_GET_SEGMENT (symp) == undefined_section)
+               S_SET_SEGMENT (symp,
+                              S_GET_SEGMENT (symp->sy_value.X_add_symbol));
+           }
 
          resolved = symp->sy_value.X_add_symbol->sy_resolved;
          break;
@@ -708,39 +740,6 @@ resolve_symbol_value (symp)
          resolved = symp->sy_value.X_add_symbol->sy_resolved;
          break;
 
-       case O_add:
-         resolve_symbol_value (symp->sy_value.X_add_symbol);
-         resolve_symbol_value (symp->sy_value.X_op_symbol);
-         seg_left = S_GET_SEGMENT (symp->sy_value.X_add_symbol);
-         seg_right = S_GET_SEGMENT (symp->sy_value.X_op_symbol);
-         /* This case comes up with PIC support.  */
-         {
-           symbolS *s_left = symp->sy_value.X_add_symbol;
-           symbolS *s_right = symp->sy_value.X_op_symbol;
-
-           if (seg_left == absolute_section)
-             {
-               symbolS *t;
-               segT ts;
-               t = s_left;
-               s_left = s_right;
-               s_right = t;
-               ts = seg_left;
-               seg_left = seg_right;
-               seg_right = ts;
-             }
-           if (seg_right == absolute_section
-               && s_right->sy_resolved)
-             {
-               symp->sy_value.X_add_number += S_GET_VALUE (s_right);
-               symp->sy_value.X_op_symbol = 0;
-               symp->sy_value.X_add_symbol = s_left;
-               symp->sy_value.X_op = O_symbol;
-               goto reduce;
-             }
-         }
-         /* fall through */
-
        case O_multiply:
        case O_divide:
        case O_modulus:
@@ -750,6 +749,7 @@ resolve_symbol_value (symp)
        case O_bit_or_not:
        case O_bit_exclusive_or:
        case O_bit_and:
+       case O_add:
        case O_subtract:
        case O_eq:
        case O_ne:
@@ -763,38 +763,50 @@ resolve_symbol_value (symp)
          resolve_symbol_value (symp->sy_value.X_op_symbol);
          seg_left = S_GET_SEGMENT (symp->sy_value.X_add_symbol);
          seg_right = S_GET_SEGMENT (symp->sy_value.X_op_symbol);
-         if (seg_left != seg_right
-             && seg_left != undefined_section
-             && seg_right != undefined_section)
-           {
-             char *file;
-             unsigned int line;
+         left = S_GET_VALUE (symp->sy_value.X_add_symbol);
+         right = S_GET_VALUE (symp->sy_value.X_op_symbol);
 
-             if (expr_symbol_where (symp, &file, &line))
-               as_bad_where
-                 (file, line,
-                  "illegal operation on symbols in different sections");
-             else
-               as_bad
-                 ("%s set to illegal operation on symbols in different sections",
-                  S_GET_NAME (symp));
-           }
-         if ((S_GET_SEGMENT (symp->sy_value.X_add_symbol)
-              != absolute_section)
-             && symp->sy_value.X_op != O_subtract)
+         /* Subtraction is permitted if both operands are in the same
+            section.  Otherwise, both operands must be absolute.  We
+            already handled the case of addition or subtraction of a
+            constant above.  This will probably need to be changed
+            for an object file format which supports arbitrary
+            expressions, such as IEEE-695.  */
+         if ((seg_left != absolute_section
+              || seg_right != absolute_section)
+             && (symp->sy_value.X_op != O_subtract
+                 || seg_left != seg_right))
            {
              char *file;
              unsigned int line;
 
              if (expr_symbol_where (symp, &file, &line))
-               as_bad_where (file, line,
-                             "illegal operation on non-absolute symbols");
+               {
+                 if (seg_left == undefined_section
+                     || seg_right == undefined_section)
+                   as_bad_where (file, line,
+                                 "undefined symbol %s in operation",
+                                 (seg_left == undefined_section
+                                  ? S_GET_NAME (symp->sy_value.X_add_symbol)
+                                  : S_GET_NAME (symp->sy_value.X_op_symbol)));
+                 else
+                   as_bad_where (file, line, "invalid section for operation");
+               }
              else
-               as_bad ("%s set to illegal operation on non-absolute symbols",
-                       S_GET_NAME (symp));
+               {
+                 if (seg_left == undefined_section
+                     || seg_right == undefined_section)
+                   as_bad ("undefined symbol %s in operation setting %s",
+                           (seg_left == undefined_section
+                            ? S_GET_NAME (symp->sy_value.X_add_symbol)
+                            : S_GET_NAME (symp->sy_value.X_op_symbol)),
+                           S_GET_NAME (symp));
+                 else
+                   as_bad ("invalid section for operation setting %s",
+                           S_GET_NAME (symp));
+               }
            }
-         left = S_GET_VALUE (symp->sy_value.X_add_symbol);
-         right = S_GET_VALUE (symp->sy_value.X_op_symbol);
+
          switch (symp->sy_value.X_op)
            {
            case O_multiply:            val = left * right; break;

diff --git a/gas/write.c b/gas/write.c
index 0cd68c3..a67b34a 100644 (file)
--- a/gas/write.c
+++ b/gas/write.c
@@ -874,7 +874,17 @@ write_relocs (abfd, sec, xxx)
       sym = fixp->fx_addsy;
       while (sym->sy_value.X_op == O_symbol
             && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
-       sym = sym->sy_value.X_add_symbol;
+       {
+         symbolS *n;
+
+         /* We must avoid looping, as that can occur with a badly
+            written program.  */
+         n = sym->sy_value.X_add_symbol;
+         if (n == sym)
+           break;
+         fixp->fx_offset += sym->sy_value.X_add_number;
+         sym = n;
+       }
       fixp->fx_addsy = sym;
 
       reloc = tc_gen_reloc (sec, fixp);