x86: change fetch error handling in ckprefix()

Use a tristate (enum) return value type to be able to express all three
cases which are of interest to the (sole) caller. This also allows doing
away with the abuse of "rex_used".

diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 393522f37ac6cf2f28e3b83611575500b174e209..60bfa41a5ada03d659040da46b6df4d58f43e32c 100644 (file)
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -8953,7 +8953,11 @@ static const struct dis386 rm_table[][8] = {
 #define BND_PREFIX     0x04
 #define NOTRACK_PREFIX 0x05
 
-static int
+static enum {
+  ckp_okay,
+  ckp_bogus,
+  ckp_fetch_error,
+}
 ckprefix (instr_info *ins)
 {
   int newrex, i, length;
@@ -8963,7 +8967,8 @@ ckprefix (instr_info *ins)
   /* The maximum instruction length is 15bytes.  */
   while (length < MAX_CODE_LENGTH - 1)
     {
-      FETCH_DATA (ins->info, ins->codep + 1);
+      if (!fetch_code (ins->info, ins->codep + 1))
+       return ckp_fetch_error;
       newrex = 0;
       switch (*ins->codep)
        {
@@ -8987,7 +8992,7 @@ ckprefix (instr_info *ins)
          if (ins->address_mode == mode_64bit)
            newrex = *ins->codep;
          else
-           return 1;
+           return ckp_okay;
          ins->last_rex_prefix = i;
          break;
        case 0xf3:
@@ -9055,27 +9060,23 @@ ckprefix (instr_info *ins)
              ins->codep++;
              /* This ensures that the previous REX prefixes are noticed
                 as unused prefixes, as in the return case below.  */
-             ins->rex_used = ins->rex;
-             return 1;
+             return ins->rex ? ckp_bogus : ckp_okay;
            }
          ins->prefixes = PREFIX_FWAIT;
          break;
        default:
-         return 1;
+         return ckp_okay;
        }
       /* Rex is ignored when followed by another prefix.  */
       if (ins->rex)
-       {
-         ins->rex_used = ins->rex;
-         return 1;
-       }
+       return ckp_bogus;
       if (*ins->codep != FWAIT_OPCODE)
        ins->all_prefixes[i++] = *ins->codep;
       ins->rex = newrex;
       ins->codep++;
       length++;
     }
-  return 0;
+  return ckp_bogus;
 }
 
 /* Return the name of the prefix byte PREF, or NULL if PREF is not a
@@ -9918,8 +9919,12 @@ print_insn (bfd_vma pc, disassemble_info *info, int intel_syntax)
 
   sizeflag = priv.orig_sizeflag;
 
-  if (!ckprefix (&ins) || ins.rex_used)
+  switch (ckprefix (&ins))
     {
+    case ckp_okay:
+      break;
+
+    case ckp_bogus:
       /* Too many prefixes or unused REX prefixes.  */
       for (i = 0;
           i < (int) ARRAY_SIZE (ins.all_prefixes) && ins.all_prefixes[i];
@@ -9928,6 +9933,9 @@ print_insn (bfd_vma pc, disassemble_info *info, int intel_syntax)
                         (i == 0 ? "" : " "),
                         prefix_name (&ins, ins.all_prefixes[i], sizeflag));
       return i;
+
+    case ckp_fetch_error:
+      return fetch_error (&ins);
     }
 
   ins.insn_codep = ins.codep;