From 34501e12622f129ea112c9ca36251bae51eb32f5 Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@zytor.com>
Date: Tue, 3 Mar 2026 08:40:49 -0800
Subject: [PATCH] nasm.c: add the --bits option for compatibility with 3.0x

To make it easier to run A:B testing against NASM 3.0x, which is
the whole point of this branch, add the --bits option from NASM 3.0x.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 asm/nasm.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/asm/nasm.c b/asm/nasm.c
index e97a0af96..ba68c914b 100644
--- a/asm/nasm.c
+++ b/asm/nasm.c
@@ -947,7 +947,8 @@ enum text_options {
     OPT_KEEP_ALL,
     OPT_NO_LINE,
     OPT_DEBUG,
-    OPT_REPRODUCIBLE
+    OPT_REPRODUCIBLE,
+    OPT_BITS
 };
 enum need_arg {
     ARG_NO,
@@ -980,6 +981,7 @@ static const struct textargs textopts[] = {
     {"no-line",  OPT_NO_LINE, ARG_NO, 0},
     {"debug",    OPT_DEBUG, ARG_MAYBE, 0},
     {"reproducible", OPT_REPRODUCIBLE, ARG_NO, 0},
+    {"bits",     OPT_BITS, ARG_YES, 0},
     {NULL, OPT_BOGUS, ARG_NO, 0}
 };
 
@@ -1350,6 +1352,18 @@ static bool process_arg(char *p, char *q, int pass)
                 case OPT_REPRODUCIBLE:
                     reproducible = true;
                     break;
+                case OPT_BITS:
+                    if (pass == 2) {
+                        int bits = strtoul(param, NULL, 10);
+                        if (bits != 16 && bits != 32 && bits != 64) {
+                            nasm_nonfatalf(ERR_USAGE, "invalid argument to --bits");
+                        } else {
+                            char cmdbuf[16];
+                            snprintf(cmdbuf,sizeof(cmdbuf),"[bits %d]", bits);
+                            pp_pre_command(NULL, cmdbuf);
+                        }
+                    }
+                    break;
                 case OPT_HELP:
                     /* Allow --help topic without *requiring* topic */
                     if (!param)